xref: /linux/drivers/tty/synclink_gt.c (revision ff40b5769a50fab654a70575ff0f49853b799b0e)
1 // SPDX-License-Identifier: GPL-1.0+
2 /*
3  * Device driver for Microgate SyncLink GT serial adapters.
4  *
5  * written by Paul Fulghum for Microgate Corporation
6  * paulkf@microgate.com
7  *
8  * Microgate and SyncLink are trademarks of Microgate Corporation
9  *
10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
11  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
12  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
13  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
14  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
15  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
16  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
17  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
18  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
19  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
20  * OF THE POSSIBILITY OF SUCH DAMAGE.
21  */
22 
23 /*
24  * DEBUG OUTPUT DEFINITIONS
25  *
26  * uncomment lines below to enable specific types of debug output
27  *
28  * DBGINFO   information - most verbose output
29  * DBGERR    serious errors
30  * DBGBH     bottom half service routine debugging
31  * DBGISR    interrupt service routine debugging
32  * DBGDATA   output receive and transmit data
33  * DBGTBUF   output transmit DMA buffers and registers
34  * DBGRBUF   output receive DMA buffers and registers
35  */
36 
37 #define DBGINFO(fmt) if (debug_level >= DEBUG_LEVEL_INFO) printk fmt
38 #define DBGERR(fmt) if (debug_level >= DEBUG_LEVEL_ERROR) printk fmt
39 #define DBGBH(fmt) if (debug_level >= DEBUG_LEVEL_BH) printk fmt
40 #define DBGISR(fmt) if (debug_level >= DEBUG_LEVEL_ISR) printk fmt
41 #define DBGDATA(info, buf, size, label) if (debug_level >= DEBUG_LEVEL_DATA) trace_block((info), (buf), (size), (label))
42 /*#define DBGTBUF(info) dump_tbufs(info)*/
43 /*#define DBGRBUF(info) dump_rbufs(info)*/
44 
45 
46 #include <linux/module.h>
47 #include <linux/errno.h>
48 #include <linux/signal.h>
49 #include <linux/sched.h>
50 #include <linux/timer.h>
51 #include <linux/interrupt.h>
52 #include <linux/pci.h>
53 #include <linux/tty.h>
54 #include <linux/tty_flip.h>
55 #include <linux/serial.h>
56 #include <linux/major.h>
57 #include <linux/string.h>
58 #include <linux/fcntl.h>
59 #include <linux/ptrace.h>
60 #include <linux/ioport.h>
61 #include <linux/mm.h>
62 #include <linux/seq_file.h>
63 #include <linux/slab.h>
64 #include <linux/netdevice.h>
65 #include <linux/vmalloc.h>
66 #include <linux/init.h>
67 #include <linux/delay.h>
68 #include <linux/ioctl.h>
69 #include <linux/termios.h>
70 #include <linux/bitops.h>
71 #include <linux/workqueue.h>
72 #include <linux/hdlc.h>
73 #include <linux/synclink.h>
74 
75 #include <asm/io.h>
76 #include <asm/irq.h>
77 #include <asm/dma.h>
78 #include <asm/types.h>
79 #include <linux/uaccess.h>
80 
81 #if defined(CONFIG_HDLC) || (defined(CONFIG_HDLC_MODULE) && defined(CONFIG_SYNCLINK_GT_MODULE))
82 #define SYNCLINK_GENERIC_HDLC 1
83 #else
84 #define SYNCLINK_GENERIC_HDLC 0
85 #endif
86 
87 /*
88  * module identification
89  */
90 static char *driver_name     = "SyncLink GT";
91 static char *slgt_driver_name = "synclink_gt";
92 static char *tty_dev_prefix  = "ttySLG";
93 MODULE_LICENSE("GPL");
94 #define MAX_DEVICES 32
95 
96 static const struct pci_device_id pci_table[] = {
97 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
98 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT2_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
99 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT4_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
100 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_AC_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
101 	{0,}, /* terminate list */
102 };
103 MODULE_DEVICE_TABLE(pci, pci_table);
104 
105 static int  init_one(struct pci_dev *dev,const struct pci_device_id *ent);
106 static void remove_one(struct pci_dev *dev);
107 static struct pci_driver pci_driver = {
108 	.name		= "synclink_gt",
109 	.id_table	= pci_table,
110 	.probe		= init_one,
111 	.remove		= remove_one,
112 };
113 
114 static bool pci_registered;
115 
116 /*
117  * module configuration and status
118  */
119 static struct slgt_info *slgt_device_list;
120 static int slgt_device_count;
121 
122 static int ttymajor;
123 static int debug_level;
124 static int maxframe[MAX_DEVICES];
125 
126 module_param(ttymajor, int, 0);
127 module_param(debug_level, int, 0);
128 module_param_array(maxframe, int, NULL, 0);
129 
130 MODULE_PARM_DESC(ttymajor, "TTY major device number override: 0=auto assigned");
131 MODULE_PARM_DESC(debug_level, "Debug syslog output: 0=disabled, 1 to 5=increasing detail");
132 MODULE_PARM_DESC(maxframe, "Maximum frame size used by device (4096 to 65535)");
133 
134 /*
135  * tty support and callbacks
136  */
137 static struct tty_driver *serial_driver;
138 
139 static void wait_until_sent(struct tty_struct *tty, int timeout);
140 static void flush_buffer(struct tty_struct *tty);
141 static void tx_release(struct tty_struct *tty);
142 
143 /*
144  * generic HDLC support
145  */
146 #define dev_to_port(D) (dev_to_hdlc(D)->priv)
147 
148 
149 /*
150  * device specific structures, macros and functions
151  */
152 
153 #define SLGT_MAX_PORTS 4
154 #define SLGT_REG_SIZE  256
155 
156 /*
157  * conditional wait facility
158  */
159 struct cond_wait {
160 	struct cond_wait *next;
161 	wait_queue_head_t q;
162 	wait_queue_entry_t wait;
163 	unsigned int data;
164 };
165 static void flush_cond_wait(struct cond_wait **head);
166 
167 /*
168  * DMA buffer descriptor and access macros
169  */
170 struct slgt_desc
171 {
172 	__le16 count;
173 	__le16 status;
174 	__le32 pbuf;  /* physical address of data buffer */
175 	__le32 next;  /* physical address of next descriptor */
176 
177 	/* driver book keeping */
178 	char *buf;          /* virtual  address of data buffer */
179     	unsigned int pdesc; /* physical address of this descriptor */
180 	dma_addr_t buf_dma_addr;
181 	unsigned short buf_count;
182 };
183 
184 #define set_desc_buffer(a,b) (a).pbuf = cpu_to_le32((unsigned int)(b))
185 #define set_desc_next(a,b) (a).next   = cpu_to_le32((unsigned int)(b))
186 #define set_desc_count(a,b)(a).count  = cpu_to_le16((unsigned short)(b))
187 #define set_desc_eof(a,b)  (a).status = cpu_to_le16((b) ? (le16_to_cpu((a).status) | BIT0) : (le16_to_cpu((a).status) & ~BIT0))
188 #define set_desc_status(a, b) (a).status = cpu_to_le16((unsigned short)(b))
189 #define desc_count(a)      (le16_to_cpu((a).count))
190 #define desc_status(a)     (le16_to_cpu((a).status))
191 #define desc_complete(a)   (le16_to_cpu((a).status) & BIT15)
192 #define desc_eof(a)        (le16_to_cpu((a).status) & BIT2)
193 #define desc_crc_error(a)  (le16_to_cpu((a).status) & BIT1)
194 #define desc_abort(a)      (le16_to_cpu((a).status) & BIT0)
195 #define desc_residue(a)    ((le16_to_cpu((a).status) & 0x38) >> 3)
196 
197 struct _input_signal_events {
198 	int ri_up;
199 	int ri_down;
200 	int dsr_up;
201 	int dsr_down;
202 	int dcd_up;
203 	int dcd_down;
204 	int cts_up;
205 	int cts_down;
206 };
207 
208 /*
209  * device instance data structure
210  */
211 struct slgt_info {
212 	void *if_ptr;		/* General purpose pointer (used by SPPP) */
213 	struct tty_port port;
214 
215 	struct slgt_info *next_device;	/* device list link */
216 
217 	char device_name[25];
218 	struct pci_dev *pdev;
219 
220 	int port_count;  /* count of ports on adapter */
221 	int adapter_num; /* adapter instance number */
222 	int port_num;    /* port instance number */
223 
224 	/* array of pointers to port contexts on this adapter */
225 	struct slgt_info *port_array[SLGT_MAX_PORTS];
226 
227 	int			line;		/* tty line instance number */
228 
229 	struct mgsl_icount	icount;
230 
231 	int			timeout;
232 	int			x_char;		/* xon/xoff character */
233 	unsigned int		read_status_mask;
234 	unsigned int 		ignore_status_mask;
235 
236 	wait_queue_head_t	status_event_wait_q;
237 	wait_queue_head_t	event_wait_q;
238 	struct timer_list	tx_timer;
239 	struct timer_list	rx_timer;
240 
241 	unsigned int            gpio_present;
242 	struct cond_wait        *gpio_wait_q;
243 
244 	spinlock_t lock;	/* spinlock for synchronizing with ISR */
245 
246 	struct work_struct task;
247 	u32 pending_bh;
248 	bool bh_requested;
249 	bool bh_running;
250 
251 	int isr_overflow;
252 	bool irq_requested;	/* true if IRQ requested */
253 	bool irq_occurred;	/* for diagnostics use */
254 
255 	/* device configuration */
256 
257 	unsigned int bus_type;
258 	unsigned int irq_level;
259 	unsigned long irq_flags;
260 
261 	unsigned char __iomem * reg_addr;  /* memory mapped registers address */
262 	u32 phys_reg_addr;
263 	bool reg_addr_requested;
264 
265 	MGSL_PARAMS params;       /* communications parameters */
266 	u32 idle_mode;
267 	u32 max_frame_size;       /* as set by device config */
268 
269 	unsigned int rbuf_fill_level;
270 	unsigned int rx_pio;
271 	unsigned int if_mode;
272 	unsigned int base_clock;
273 	unsigned int xsync;
274 	unsigned int xctrl;
275 
276 	/* device status */
277 
278 	bool rx_enabled;
279 	bool rx_restart;
280 
281 	bool tx_enabled;
282 	bool tx_active;
283 
284 	unsigned char signals;    /* serial signal states */
285 	int init_error;  /* initialization error */
286 
287 	unsigned char *tx_buf;
288 	int tx_count;
289 
290 	bool drop_rts_on_tx_done;
291 	struct	_input_signal_events	input_signal_events;
292 
293 	int dcd_chkcount;	/* check counts to prevent */
294 	int cts_chkcount;	/* too many IRQs if a signal */
295 	int dsr_chkcount;	/* is floating */
296 	int ri_chkcount;
297 
298 	char *bufs;		/* virtual address of DMA buffer lists */
299 	dma_addr_t bufs_dma_addr; /* physical address of buffer descriptors */
300 
301 	unsigned int rbuf_count;
302 	struct slgt_desc *rbufs;
303 	unsigned int rbuf_current;
304 	unsigned int rbuf_index;
305 	unsigned int rbuf_fill_index;
306 	unsigned short rbuf_fill_count;
307 
308 	unsigned int tbuf_count;
309 	struct slgt_desc *tbufs;
310 	unsigned int tbuf_current;
311 	unsigned int tbuf_start;
312 
313 	unsigned char *tmp_rbuf;
314 	unsigned int tmp_rbuf_count;
315 
316 	/* SPPP/Cisco HDLC device parts */
317 
318 	int netcount;
319 	spinlock_t netlock;
320 #if SYNCLINK_GENERIC_HDLC
321 	struct net_device *netdev;
322 #endif
323 
324 };
325 
326 static MGSL_PARAMS default_params = {
327 	.mode            = MGSL_MODE_HDLC,
328 	.loopback        = 0,
329 	.flags           = HDLC_FLAG_UNDERRUN_ABORT15,
330 	.encoding        = HDLC_ENCODING_NRZI_SPACE,
331 	.clock_speed     = 0,
332 	.addr_filter     = 0xff,
333 	.crc_type        = HDLC_CRC_16_CCITT,
334 	.preamble_length = HDLC_PREAMBLE_LENGTH_8BITS,
335 	.preamble        = HDLC_PREAMBLE_PATTERN_NONE,
336 	.data_rate       = 9600,
337 	.data_bits       = 8,
338 	.stop_bits       = 1,
339 	.parity          = ASYNC_PARITY_NONE
340 };
341 
342 
343 #define BH_RECEIVE  1
344 #define BH_TRANSMIT 2
345 #define BH_STATUS   4
346 #define IO_PIN_SHUTDOWN_LIMIT 100
347 
348 #define DMABUFSIZE 256
349 #define DESC_LIST_SIZE 4096
350 
351 #define MASK_PARITY  BIT1
352 #define MASK_FRAMING BIT0
353 #define MASK_BREAK   BIT14
354 #define MASK_OVERRUN BIT4
355 
356 #define GSR   0x00 /* global status */
357 #define JCR   0x04 /* JTAG control */
358 #define IODR  0x08 /* GPIO direction */
359 #define IOER  0x0c /* GPIO interrupt enable */
360 #define IOVR  0x10 /* GPIO value */
361 #define IOSR  0x14 /* GPIO interrupt status */
362 #define TDR   0x80 /* tx data */
363 #define RDR   0x80 /* rx data */
364 #define TCR   0x82 /* tx control */
365 #define TIR   0x84 /* tx idle */
366 #define TPR   0x85 /* tx preamble */
367 #define RCR   0x86 /* rx control */
368 #define VCR   0x88 /* V.24 control */
369 #define CCR   0x89 /* clock control */
370 #define BDR   0x8a /* baud divisor */
371 #define SCR   0x8c /* serial control */
372 #define SSR   0x8e /* serial status */
373 #define RDCSR 0x90 /* rx DMA control/status */
374 #define TDCSR 0x94 /* tx DMA control/status */
375 #define RDDAR 0x98 /* rx DMA descriptor address */
376 #define TDDAR 0x9c /* tx DMA descriptor address */
377 #define XSR   0x40 /* extended sync pattern */
378 #define XCR   0x44 /* extended control */
379 
380 #define RXIDLE      BIT14
381 #define RXBREAK     BIT14
382 #define IRQ_TXDATA  BIT13
383 #define IRQ_TXIDLE  BIT12
384 #define IRQ_TXUNDER BIT11 /* HDLC */
385 #define IRQ_RXDATA  BIT10
386 #define IRQ_RXIDLE  BIT9  /* HDLC */
387 #define IRQ_RXBREAK BIT9  /* async */
388 #define IRQ_RXOVER  BIT8
389 #define IRQ_DSR     BIT7
390 #define IRQ_CTS     BIT6
391 #define IRQ_DCD     BIT5
392 #define IRQ_RI      BIT4
393 #define IRQ_ALL     0x3ff0
394 #define IRQ_MASTER  BIT0
395 
396 #define slgt_irq_on(info, mask) \
397 	wr_reg16((info), SCR, (unsigned short)(rd_reg16((info), SCR) | (mask)))
398 #define slgt_irq_off(info, mask) \
399 	wr_reg16((info), SCR, (unsigned short)(rd_reg16((info), SCR) & ~(mask)))
400 
401 static __u8  rd_reg8(struct slgt_info *info, unsigned int addr);
402 static void  wr_reg8(struct slgt_info *info, unsigned int addr, __u8 value);
403 static __u16 rd_reg16(struct slgt_info *info, unsigned int addr);
404 static void  wr_reg16(struct slgt_info *info, unsigned int addr, __u16 value);
405 static __u32 rd_reg32(struct slgt_info *info, unsigned int addr);
406 static void  wr_reg32(struct slgt_info *info, unsigned int addr, __u32 value);
407 
408 static void  msc_set_vcr(struct slgt_info *info);
409 
410 static int  startup(struct slgt_info *info);
411 static int  block_til_ready(struct tty_struct *tty, struct file * filp,struct slgt_info *info);
412 static void shutdown(struct slgt_info *info);
413 static void program_hw(struct slgt_info *info);
414 static void change_params(struct slgt_info *info);
415 
416 static int  adapter_test(struct slgt_info *info);
417 
418 static void reset_port(struct slgt_info *info);
419 static void async_mode(struct slgt_info *info);
420 static void sync_mode(struct slgt_info *info);
421 
422 static void rx_stop(struct slgt_info *info);
423 static void rx_start(struct slgt_info *info);
424 static void reset_rbufs(struct slgt_info *info);
425 static void free_rbufs(struct slgt_info *info, unsigned int first, unsigned int last);
426 static bool rx_get_frame(struct slgt_info *info);
427 static bool rx_get_buf(struct slgt_info *info);
428 
429 static void tx_start(struct slgt_info *info);
430 static void tx_stop(struct slgt_info *info);
431 static void tx_set_idle(struct slgt_info *info);
432 static unsigned int tbuf_bytes(struct slgt_info *info);
433 static void reset_tbufs(struct slgt_info *info);
434 static void tdma_reset(struct slgt_info *info);
435 static bool tx_load(struct slgt_info *info, const char *buf, unsigned int count);
436 
437 static void get_gtsignals(struct slgt_info *info);
438 static void set_gtsignals(struct slgt_info *info);
439 static void set_rate(struct slgt_info *info, u32 data_rate);
440 
441 static void bh_transmit(struct slgt_info *info);
442 static void isr_txeom(struct slgt_info *info, unsigned short status);
443 
444 static void tx_timeout(struct timer_list *t);
445 static void rx_timeout(struct timer_list *t);
446 
447 /*
448  * ioctl handlers
449  */
450 static int  get_stats(struct slgt_info *info, struct mgsl_icount __user *user_icount);
451 static int  get_params(struct slgt_info *info, MGSL_PARAMS __user *params);
452 static int  set_params(struct slgt_info *info, MGSL_PARAMS __user *params);
453 static int  get_txidle(struct slgt_info *info, int __user *idle_mode);
454 static int  set_txidle(struct slgt_info *info, int idle_mode);
455 static int  tx_enable(struct slgt_info *info, int enable);
456 static int  tx_abort(struct slgt_info *info);
457 static int  rx_enable(struct slgt_info *info, int enable);
458 static int  modem_input_wait(struct slgt_info *info,int arg);
459 static int  wait_mgsl_event(struct slgt_info *info, int __user *mask_ptr);
460 static int  get_interface(struct slgt_info *info, int __user *if_mode);
461 static int  set_interface(struct slgt_info *info, int if_mode);
462 static int  set_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
463 static int  get_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
464 static int  wait_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
465 static int  get_xsync(struct slgt_info *info, int __user *if_mode);
466 static int  set_xsync(struct slgt_info *info, int if_mode);
467 static int  get_xctrl(struct slgt_info *info, int __user *if_mode);
468 static int  set_xctrl(struct slgt_info *info, int if_mode);
469 
470 /*
471  * driver functions
472  */
473 static void release_resources(struct slgt_info *info);
474 
475 /*
476  * DEBUG OUTPUT CODE
477  */
478 #ifndef DBGINFO
479 #define DBGINFO(fmt)
480 #endif
481 #ifndef DBGERR
482 #define DBGERR(fmt)
483 #endif
484 #ifndef DBGBH
485 #define DBGBH(fmt)
486 #endif
487 #ifndef DBGISR
488 #define DBGISR(fmt)
489 #endif
490 
491 #ifdef DBGDATA
492 static void trace_block(struct slgt_info *info, const char *data, int count, const char *label)
493 {
494 	int i;
495 	int linecount;
496 	printk("%s %s data:\n",info->device_name, label);
497 	while(count) {
498 		linecount = (count > 16) ? 16 : count;
499 		for(i=0; i < linecount; i++)
500 			printk("%02X ",(unsigned char)data[i]);
501 		for(;i<17;i++)
502 			printk("   ");
503 		for(i=0;i<linecount;i++) {
504 			if (data[i]>=040 && data[i]<=0176)
505 				printk("%c",data[i]);
506 			else
507 				printk(".");
508 		}
509 		printk("\n");
510 		data  += linecount;
511 		count -= linecount;
512 	}
513 }
514 #else
515 #define DBGDATA(info, buf, size, label)
516 #endif
517 
518 #ifdef DBGTBUF
519 static void dump_tbufs(struct slgt_info *info)
520 {
521 	int i;
522 	printk("tbuf_current=%d\n", info->tbuf_current);
523 	for (i=0 ; i < info->tbuf_count ; i++) {
524 		printk("%d: count=%04X status=%04X\n",
525 			i, le16_to_cpu(info->tbufs[i].count), le16_to_cpu(info->tbufs[i].status));
526 	}
527 }
528 #else
529 #define DBGTBUF(info)
530 #endif
531 
532 #ifdef DBGRBUF
533 static void dump_rbufs(struct slgt_info *info)
534 {
535 	int i;
536 	printk("rbuf_current=%d\n", info->rbuf_current);
537 	for (i=0 ; i < info->rbuf_count ; i++) {
538 		printk("%d: count=%04X status=%04X\n",
539 			i, le16_to_cpu(info->rbufs[i].count), le16_to_cpu(info->rbufs[i].status));
540 	}
541 }
542 #else
543 #define DBGRBUF(info)
544 #endif
545 
546 static inline int sanity_check(struct slgt_info *info, char *devname, const char *name)
547 {
548 #ifdef SANITY_CHECK
549 	if (!info) {
550 		printk("null struct slgt_info for (%s) in %s\n", devname, name);
551 		return 1;
552 	}
553 #else
554 	if (!info)
555 		return 1;
556 #endif
557 	return 0;
558 }
559 
560 /*
561  * line discipline callback wrappers
562  *
563  * The wrappers maintain line discipline references
564  * while calling into the line discipline.
565  *
566  * ldisc_receive_buf  - pass receive data to line discipline
567  */
568 static void ldisc_receive_buf(struct tty_struct *tty,
569 			      const __u8 *data, char *flags, int count)
570 {
571 	struct tty_ldisc *ld;
572 	if (!tty)
573 		return;
574 	ld = tty_ldisc_ref(tty);
575 	if (ld) {
576 		if (ld->ops->receive_buf)
577 			ld->ops->receive_buf(tty, data, flags, count);
578 		tty_ldisc_deref(ld);
579 	}
580 }
581 
582 /* tty callbacks */
583 
584 static int open(struct tty_struct *tty, struct file *filp)
585 {
586 	struct slgt_info *info;
587 	int retval, line;
588 	unsigned long flags;
589 
590 	line = tty->index;
591 	if (line >= slgt_device_count) {
592 		DBGERR(("%s: open with invalid line #%d.\n", driver_name, line));
593 		return -ENODEV;
594 	}
595 
596 	info = slgt_device_list;
597 	while(info && info->line != line)
598 		info = info->next_device;
599 	if (sanity_check(info, tty->name, "open"))
600 		return -ENODEV;
601 	if (info->init_error) {
602 		DBGERR(("%s init error=%d\n", info->device_name, info->init_error));
603 		return -ENODEV;
604 	}
605 
606 	tty->driver_data = info;
607 	info->port.tty = tty;
608 
609 	DBGINFO(("%s open, old ref count = %d\n", info->device_name, info->port.count));
610 
611 	mutex_lock(&info->port.mutex);
612 
613 	spin_lock_irqsave(&info->netlock, flags);
614 	if (info->netcount) {
615 		retval = -EBUSY;
616 		spin_unlock_irqrestore(&info->netlock, flags);
617 		mutex_unlock(&info->port.mutex);
618 		goto cleanup;
619 	}
620 	info->port.count++;
621 	spin_unlock_irqrestore(&info->netlock, flags);
622 
623 	if (info->port.count == 1) {
624 		/* 1st open on this device, init hardware */
625 		retval = startup(info);
626 		if (retval < 0) {
627 			mutex_unlock(&info->port.mutex);
628 			goto cleanup;
629 		}
630 	}
631 	mutex_unlock(&info->port.mutex);
632 	retval = block_til_ready(tty, filp, info);
633 	if (retval) {
634 		DBGINFO(("%s block_til_ready rc=%d\n", info->device_name, retval));
635 		goto cleanup;
636 	}
637 
638 	retval = 0;
639 
640 cleanup:
641 	if (retval) {
642 		if (tty->count == 1)
643 			info->port.tty = NULL; /* tty layer will release tty struct */
644 		if(info->port.count)
645 			info->port.count--;
646 	}
647 
648 	DBGINFO(("%s open rc=%d\n", info->device_name, retval));
649 	return retval;
650 }
651 
652 static void close(struct tty_struct *tty, struct file *filp)
653 {
654 	struct slgt_info *info = tty->driver_data;
655 
656 	if (sanity_check(info, tty->name, "close"))
657 		return;
658 	DBGINFO(("%s close entry, count=%d\n", info->device_name, info->port.count));
659 
660 	if (tty_port_close_start(&info->port, tty, filp) == 0)
661 		goto cleanup;
662 
663 	mutex_lock(&info->port.mutex);
664 	if (tty_port_initialized(&info->port))
665  		wait_until_sent(tty, info->timeout);
666 	flush_buffer(tty);
667 	tty_ldisc_flush(tty);
668 
669 	shutdown(info);
670 	mutex_unlock(&info->port.mutex);
671 
672 	tty_port_close_end(&info->port, tty);
673 	info->port.tty = NULL;
674 cleanup:
675 	DBGINFO(("%s close exit, count=%d\n", tty->driver->name, info->port.count));
676 }
677 
678 static void hangup(struct tty_struct *tty)
679 {
680 	struct slgt_info *info = tty->driver_data;
681 	unsigned long flags;
682 
683 	if (sanity_check(info, tty->name, "hangup"))
684 		return;
685 	DBGINFO(("%s hangup\n", info->device_name));
686 
687 	flush_buffer(tty);
688 
689 	mutex_lock(&info->port.mutex);
690 	shutdown(info);
691 
692 	spin_lock_irqsave(&info->port.lock, flags);
693 	info->port.count = 0;
694 	info->port.tty = NULL;
695 	spin_unlock_irqrestore(&info->port.lock, flags);
696 	tty_port_set_active(&info->port, false);
697 	mutex_unlock(&info->port.mutex);
698 
699 	wake_up_interruptible(&info->port.open_wait);
700 }
701 
702 static void set_termios(struct tty_struct *tty,
703 			const struct ktermios *old_termios)
704 {
705 	struct slgt_info *info = tty->driver_data;
706 	unsigned long flags;
707 
708 	DBGINFO(("%s set_termios\n", tty->driver->name));
709 
710 	change_params(info);
711 
712 	/* Handle transition to B0 status */
713 	if ((old_termios->c_cflag & CBAUD) && !C_BAUD(tty)) {
714 		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
715 		spin_lock_irqsave(&info->lock,flags);
716 		set_gtsignals(info);
717 		spin_unlock_irqrestore(&info->lock,flags);
718 	}
719 
720 	/* Handle transition away from B0 status */
721 	if (!(old_termios->c_cflag & CBAUD) && C_BAUD(tty)) {
722 		info->signals |= SerialSignal_DTR;
723 		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
724 			info->signals |= SerialSignal_RTS;
725 		spin_lock_irqsave(&info->lock,flags);
726 	 	set_gtsignals(info);
727 		spin_unlock_irqrestore(&info->lock,flags);
728 	}
729 
730 	/* Handle turning off CRTSCTS */
731 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
732 		tty->hw_stopped = false;
733 		tx_release(tty);
734 	}
735 }
736 
737 static void update_tx_timer(struct slgt_info *info)
738 {
739 	/*
740 	 * use worst case speed of 1200bps to calculate transmit timeout
741 	 * based on data in buffers (tbuf_bytes) and FIFO (128 bytes)
742 	 */
743 	if (info->params.mode == MGSL_MODE_HDLC) {
744 		int timeout  = (tbuf_bytes(info) * 7) + 1000;
745 		mod_timer(&info->tx_timer, jiffies + msecs_to_jiffies(timeout));
746 	}
747 }
748 
749 static int write(struct tty_struct *tty,
750 		 const unsigned char *buf, int count)
751 {
752 	int ret = 0;
753 	struct slgt_info *info = tty->driver_data;
754 	unsigned long flags;
755 
756 	if (sanity_check(info, tty->name, "write"))
757 		return -EIO;
758 
759 	DBGINFO(("%s write count=%d\n", info->device_name, count));
760 
761 	if (!info->tx_buf || (count > info->max_frame_size))
762 		return -EIO;
763 
764 	if (!count || tty->flow.stopped || tty->hw_stopped)
765 		return 0;
766 
767 	spin_lock_irqsave(&info->lock, flags);
768 
769 	if (info->tx_count) {
770 		/* send accumulated data from send_char() */
771 		if (!tx_load(info, info->tx_buf, info->tx_count))
772 			goto cleanup;
773 		info->tx_count = 0;
774 	}
775 
776 	if (tx_load(info, buf, count))
777 		ret = count;
778 
779 cleanup:
780 	spin_unlock_irqrestore(&info->lock, flags);
781 	DBGINFO(("%s write rc=%d\n", info->device_name, ret));
782 	return ret;
783 }
784 
785 static int put_char(struct tty_struct *tty, unsigned char ch)
786 {
787 	struct slgt_info *info = tty->driver_data;
788 	unsigned long flags;
789 	int ret = 0;
790 
791 	if (sanity_check(info, tty->name, "put_char"))
792 		return 0;
793 	DBGINFO(("%s put_char(%d)\n", info->device_name, ch));
794 	if (!info->tx_buf)
795 		return 0;
796 	spin_lock_irqsave(&info->lock,flags);
797 	if (info->tx_count < info->max_frame_size) {
798 		info->tx_buf[info->tx_count++] = ch;
799 		ret = 1;
800 	}
801 	spin_unlock_irqrestore(&info->lock,flags);
802 	return ret;
803 }
804 
805 static void send_xchar(struct tty_struct *tty, char ch)
806 {
807 	struct slgt_info *info = tty->driver_data;
808 	unsigned long flags;
809 
810 	if (sanity_check(info, tty->name, "send_xchar"))
811 		return;
812 	DBGINFO(("%s send_xchar(%d)\n", info->device_name, ch));
813 	info->x_char = ch;
814 	if (ch) {
815 		spin_lock_irqsave(&info->lock,flags);
816 		if (!info->tx_enabled)
817 		 	tx_start(info);
818 		spin_unlock_irqrestore(&info->lock,flags);
819 	}
820 }
821 
822 static void wait_until_sent(struct tty_struct *tty, int timeout)
823 {
824 	struct slgt_info *info = tty->driver_data;
825 	unsigned long orig_jiffies, char_time;
826 
827 	if (!info )
828 		return;
829 	if (sanity_check(info, tty->name, "wait_until_sent"))
830 		return;
831 	DBGINFO(("%s wait_until_sent entry\n", info->device_name));
832 	if (!tty_port_initialized(&info->port))
833 		goto exit;
834 
835 	orig_jiffies = jiffies;
836 
837 	/* Set check interval to 1/5 of estimated time to
838 	 * send a character, and make it at least 1. The check
839 	 * interval should also be less than the timeout.
840 	 * Note: use tight timings here to satisfy the NIST-PCTS.
841 	 */
842 
843 	if (info->params.data_rate) {
844 	       	char_time = info->timeout/(32 * 5);
845 		if (!char_time)
846 			char_time++;
847 	} else
848 		char_time = 1;
849 
850 	if (timeout)
851 		char_time = min_t(unsigned long, char_time, timeout);
852 
853 	while (info->tx_active) {
854 		msleep_interruptible(jiffies_to_msecs(char_time));
855 		if (signal_pending(current))
856 			break;
857 		if (timeout && time_after(jiffies, orig_jiffies + timeout))
858 			break;
859 	}
860 exit:
861 	DBGINFO(("%s wait_until_sent exit\n", info->device_name));
862 }
863 
864 static unsigned int write_room(struct tty_struct *tty)
865 {
866 	struct slgt_info *info = tty->driver_data;
867 	unsigned int ret;
868 
869 	if (sanity_check(info, tty->name, "write_room"))
870 		return 0;
871 	ret = (info->tx_active) ? 0 : HDLC_MAX_FRAME_SIZE;
872 	DBGINFO(("%s write_room=%u\n", info->device_name, ret));
873 	return ret;
874 }
875 
876 static void flush_chars(struct tty_struct *tty)
877 {
878 	struct slgt_info *info = tty->driver_data;
879 	unsigned long flags;
880 
881 	if (sanity_check(info, tty->name, "flush_chars"))
882 		return;
883 	DBGINFO(("%s flush_chars entry tx_count=%d\n", info->device_name, info->tx_count));
884 
885 	if (info->tx_count <= 0 || tty->flow.stopped ||
886 	    tty->hw_stopped || !info->tx_buf)
887 		return;
888 
889 	DBGINFO(("%s flush_chars start transmit\n", info->device_name));
890 
891 	spin_lock_irqsave(&info->lock,flags);
892 	if (info->tx_count && tx_load(info, info->tx_buf, info->tx_count))
893 		info->tx_count = 0;
894 	spin_unlock_irqrestore(&info->lock,flags);
895 }
896 
897 static void flush_buffer(struct tty_struct *tty)
898 {
899 	struct slgt_info *info = tty->driver_data;
900 	unsigned long flags;
901 
902 	if (sanity_check(info, tty->name, "flush_buffer"))
903 		return;
904 	DBGINFO(("%s flush_buffer\n", info->device_name));
905 
906 	spin_lock_irqsave(&info->lock, flags);
907 	info->tx_count = 0;
908 	spin_unlock_irqrestore(&info->lock, flags);
909 
910 	tty_wakeup(tty);
911 }
912 
913 /*
914  * throttle (stop) transmitter
915  */
916 static void tx_hold(struct tty_struct *tty)
917 {
918 	struct slgt_info *info = tty->driver_data;
919 	unsigned long flags;
920 
921 	if (sanity_check(info, tty->name, "tx_hold"))
922 		return;
923 	DBGINFO(("%s tx_hold\n", info->device_name));
924 	spin_lock_irqsave(&info->lock,flags);
925 	if (info->tx_enabled && info->params.mode == MGSL_MODE_ASYNC)
926 	 	tx_stop(info);
927 	spin_unlock_irqrestore(&info->lock,flags);
928 }
929 
930 /*
931  * release (start) transmitter
932  */
933 static void tx_release(struct tty_struct *tty)
934 {
935 	struct slgt_info *info = tty->driver_data;
936 	unsigned long flags;
937 
938 	if (sanity_check(info, tty->name, "tx_release"))
939 		return;
940 	DBGINFO(("%s tx_release\n", info->device_name));
941 	spin_lock_irqsave(&info->lock, flags);
942 	if (info->tx_count && tx_load(info, info->tx_buf, info->tx_count))
943 		info->tx_count = 0;
944 	spin_unlock_irqrestore(&info->lock, flags);
945 }
946 
947 /*
948  * Service an IOCTL request
949  *
950  * Arguments
951  *
952  * 	tty	pointer to tty instance data
953  * 	cmd	IOCTL command code
954  * 	arg	command argument/context
955  *
956  * Return 0 if success, otherwise error code
957  */
958 static int ioctl(struct tty_struct *tty,
959 		 unsigned int cmd, unsigned long arg)
960 {
961 	struct slgt_info *info = tty->driver_data;
962 	void __user *argp = (void __user *)arg;
963 	int ret;
964 
965 	if (sanity_check(info, tty->name, "ioctl"))
966 		return -ENODEV;
967 	DBGINFO(("%s ioctl() cmd=%08X\n", info->device_name, cmd));
968 
969 	if (cmd != TIOCMIWAIT) {
970 		if (tty_io_error(tty))
971 		    return -EIO;
972 	}
973 
974 	switch (cmd) {
975 	case MGSL_IOCWAITEVENT:
976 		return wait_mgsl_event(info, argp);
977 	case TIOCMIWAIT:
978 		return modem_input_wait(info,(int)arg);
979 	case MGSL_IOCSGPIO:
980 		return set_gpio(info, argp);
981 	case MGSL_IOCGGPIO:
982 		return get_gpio(info, argp);
983 	case MGSL_IOCWAITGPIO:
984 		return wait_gpio(info, argp);
985 	case MGSL_IOCGXSYNC:
986 		return get_xsync(info, argp);
987 	case MGSL_IOCSXSYNC:
988 		return set_xsync(info, (int)arg);
989 	case MGSL_IOCGXCTRL:
990 		return get_xctrl(info, argp);
991 	case MGSL_IOCSXCTRL:
992 		return set_xctrl(info, (int)arg);
993 	}
994 	mutex_lock(&info->port.mutex);
995 	switch (cmd) {
996 	case MGSL_IOCGPARAMS:
997 		ret = get_params(info, argp);
998 		break;
999 	case MGSL_IOCSPARAMS:
1000 		ret = set_params(info, argp);
1001 		break;
1002 	case MGSL_IOCGTXIDLE:
1003 		ret = get_txidle(info, argp);
1004 		break;
1005 	case MGSL_IOCSTXIDLE:
1006 		ret = set_txidle(info, (int)arg);
1007 		break;
1008 	case MGSL_IOCTXENABLE:
1009 		ret = tx_enable(info, (int)arg);
1010 		break;
1011 	case MGSL_IOCRXENABLE:
1012 		ret = rx_enable(info, (int)arg);
1013 		break;
1014 	case MGSL_IOCTXABORT:
1015 		ret = tx_abort(info);
1016 		break;
1017 	case MGSL_IOCGSTATS:
1018 		ret = get_stats(info, argp);
1019 		break;
1020 	case MGSL_IOCGIF:
1021 		ret = get_interface(info, argp);
1022 		break;
1023 	case MGSL_IOCSIF:
1024 		ret = set_interface(info,(int)arg);
1025 		break;
1026 	default:
1027 		ret = -ENOIOCTLCMD;
1028 	}
1029 	mutex_unlock(&info->port.mutex);
1030 	return ret;
1031 }
1032 
1033 static int get_icount(struct tty_struct *tty,
1034 				struct serial_icounter_struct *icount)
1035 
1036 {
1037 	struct slgt_info *info = tty->driver_data;
1038 	struct mgsl_icount cnow;	/* kernel counter temps */
1039 	unsigned long flags;
1040 
1041 	spin_lock_irqsave(&info->lock,flags);
1042 	cnow = info->icount;
1043 	spin_unlock_irqrestore(&info->lock,flags);
1044 
1045 	icount->cts = cnow.cts;
1046 	icount->dsr = cnow.dsr;
1047 	icount->rng = cnow.rng;
1048 	icount->dcd = cnow.dcd;
1049 	icount->rx = cnow.rx;
1050 	icount->tx = cnow.tx;
1051 	icount->frame = cnow.frame;
1052 	icount->overrun = cnow.overrun;
1053 	icount->parity = cnow.parity;
1054 	icount->brk = cnow.brk;
1055 	icount->buf_overrun = cnow.buf_overrun;
1056 
1057 	return 0;
1058 }
1059 
1060 /*
1061  * support for 32 bit ioctl calls on 64 bit systems
1062  */
1063 #ifdef CONFIG_COMPAT
1064 static long get_params32(struct slgt_info *info, struct MGSL_PARAMS32 __user *user_params)
1065 {
1066 	struct MGSL_PARAMS32 tmp_params;
1067 
1068 	DBGINFO(("%s get_params32\n", info->device_name));
1069 	memset(&tmp_params, 0, sizeof(tmp_params));
1070 	tmp_params.mode            = (compat_ulong_t)info->params.mode;
1071 	tmp_params.loopback        = info->params.loopback;
1072 	tmp_params.flags           = info->params.flags;
1073 	tmp_params.encoding        = info->params.encoding;
1074 	tmp_params.clock_speed     = (compat_ulong_t)info->params.clock_speed;
1075 	tmp_params.addr_filter     = info->params.addr_filter;
1076 	tmp_params.crc_type        = info->params.crc_type;
1077 	tmp_params.preamble_length = info->params.preamble_length;
1078 	tmp_params.preamble        = info->params.preamble;
1079 	tmp_params.data_rate       = (compat_ulong_t)info->params.data_rate;
1080 	tmp_params.data_bits       = info->params.data_bits;
1081 	tmp_params.stop_bits       = info->params.stop_bits;
1082 	tmp_params.parity          = info->params.parity;
1083 	if (copy_to_user(user_params, &tmp_params, sizeof(struct MGSL_PARAMS32)))
1084 		return -EFAULT;
1085 	return 0;
1086 }
1087 
1088 static long set_params32(struct slgt_info *info, struct MGSL_PARAMS32 __user *new_params)
1089 {
1090 	struct MGSL_PARAMS32 tmp_params;
1091 
1092 	DBGINFO(("%s set_params32\n", info->device_name));
1093 	if (copy_from_user(&tmp_params, new_params, sizeof(struct MGSL_PARAMS32)))
1094 		return -EFAULT;
1095 
1096 	spin_lock(&info->lock);
1097 	if (tmp_params.mode == MGSL_MODE_BASE_CLOCK) {
1098 		info->base_clock = tmp_params.clock_speed;
1099 	} else {
1100 		info->params.mode            = tmp_params.mode;
1101 		info->params.loopback        = tmp_params.loopback;
1102 		info->params.flags           = tmp_params.flags;
1103 		info->params.encoding        = tmp_params.encoding;
1104 		info->params.clock_speed     = tmp_params.clock_speed;
1105 		info->params.addr_filter     = tmp_params.addr_filter;
1106 		info->params.crc_type        = tmp_params.crc_type;
1107 		info->params.preamble_length = tmp_params.preamble_length;
1108 		info->params.preamble        = tmp_params.preamble;
1109 		info->params.data_rate       = tmp_params.data_rate;
1110 		info->params.data_bits       = tmp_params.data_bits;
1111 		info->params.stop_bits       = tmp_params.stop_bits;
1112 		info->params.parity          = tmp_params.parity;
1113 	}
1114 	spin_unlock(&info->lock);
1115 
1116 	program_hw(info);
1117 
1118 	return 0;
1119 }
1120 
1121 static long slgt_compat_ioctl(struct tty_struct *tty,
1122 			 unsigned int cmd, unsigned long arg)
1123 {
1124 	struct slgt_info *info = tty->driver_data;
1125 	int rc;
1126 
1127 	if (sanity_check(info, tty->name, "compat_ioctl"))
1128 		return -ENODEV;
1129 	DBGINFO(("%s compat_ioctl() cmd=%08X\n", info->device_name, cmd));
1130 
1131 	switch (cmd) {
1132 	case MGSL_IOCSPARAMS32:
1133 		rc = set_params32(info, compat_ptr(arg));
1134 		break;
1135 
1136 	case MGSL_IOCGPARAMS32:
1137 		rc = get_params32(info, compat_ptr(arg));
1138 		break;
1139 
1140 	case MGSL_IOCGPARAMS:
1141 	case MGSL_IOCSPARAMS:
1142 	case MGSL_IOCGTXIDLE:
1143 	case MGSL_IOCGSTATS:
1144 	case MGSL_IOCWAITEVENT:
1145 	case MGSL_IOCGIF:
1146 	case MGSL_IOCSGPIO:
1147 	case MGSL_IOCGGPIO:
1148 	case MGSL_IOCWAITGPIO:
1149 	case MGSL_IOCGXSYNC:
1150 	case MGSL_IOCGXCTRL:
1151 		rc = ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
1152 		break;
1153 	default:
1154 		rc = ioctl(tty, cmd, arg);
1155 	}
1156 	DBGINFO(("%s compat_ioctl() cmd=%08X rc=%d\n", info->device_name, cmd, rc));
1157 	return rc;
1158 }
1159 #else
1160 #define slgt_compat_ioctl NULL
1161 #endif /* ifdef CONFIG_COMPAT */
1162 
1163 /*
1164  * proc fs support
1165  */
1166 static inline void line_info(struct seq_file *m, struct slgt_info *info)
1167 {
1168 	char stat_buf[30];
1169 	unsigned long flags;
1170 
1171 	seq_printf(m, "%s: IO=%08X IRQ=%d MaxFrameSize=%u\n",
1172 		      info->device_name, info->phys_reg_addr,
1173 		      info->irq_level, info->max_frame_size);
1174 
1175 	/* output current serial signal states */
1176 	spin_lock_irqsave(&info->lock,flags);
1177 	get_gtsignals(info);
1178 	spin_unlock_irqrestore(&info->lock,flags);
1179 
1180 	stat_buf[0] = 0;
1181 	stat_buf[1] = 0;
1182 	if (info->signals & SerialSignal_RTS)
1183 		strcat(stat_buf, "|RTS");
1184 	if (info->signals & SerialSignal_CTS)
1185 		strcat(stat_buf, "|CTS");
1186 	if (info->signals & SerialSignal_DTR)
1187 		strcat(stat_buf, "|DTR");
1188 	if (info->signals & SerialSignal_DSR)
1189 		strcat(stat_buf, "|DSR");
1190 	if (info->signals & SerialSignal_DCD)
1191 		strcat(stat_buf, "|CD");
1192 	if (info->signals & SerialSignal_RI)
1193 		strcat(stat_buf, "|RI");
1194 
1195 	if (info->params.mode != MGSL_MODE_ASYNC) {
1196 		seq_printf(m, "\tHDLC txok:%d rxok:%d",
1197 			       info->icount.txok, info->icount.rxok);
1198 		if (info->icount.txunder)
1199 			seq_printf(m, " txunder:%d", info->icount.txunder);
1200 		if (info->icount.txabort)
1201 			seq_printf(m, " txabort:%d", info->icount.txabort);
1202 		if (info->icount.rxshort)
1203 			seq_printf(m, " rxshort:%d", info->icount.rxshort);
1204 		if (info->icount.rxlong)
1205 			seq_printf(m, " rxlong:%d", info->icount.rxlong);
1206 		if (info->icount.rxover)
1207 			seq_printf(m, " rxover:%d", info->icount.rxover);
1208 		if (info->icount.rxcrc)
1209 			seq_printf(m, " rxcrc:%d", info->icount.rxcrc);
1210 	} else {
1211 		seq_printf(m, "\tASYNC tx:%d rx:%d",
1212 			       info->icount.tx, info->icount.rx);
1213 		if (info->icount.frame)
1214 			seq_printf(m, " fe:%d", info->icount.frame);
1215 		if (info->icount.parity)
1216 			seq_printf(m, " pe:%d", info->icount.parity);
1217 		if (info->icount.brk)
1218 			seq_printf(m, " brk:%d", info->icount.brk);
1219 		if (info->icount.overrun)
1220 			seq_printf(m, " oe:%d", info->icount.overrun);
1221 	}
1222 
1223 	/* Append serial signal status to end */
1224 	seq_printf(m, " %s\n", stat_buf+1);
1225 
1226 	seq_printf(m, "\ttxactive=%d bh_req=%d bh_run=%d pending_bh=%x\n",
1227 		       info->tx_active,info->bh_requested,info->bh_running,
1228 		       info->pending_bh);
1229 }
1230 
1231 /* Called to print information about devices
1232  */
1233 static int synclink_gt_proc_show(struct seq_file *m, void *v)
1234 {
1235 	struct slgt_info *info;
1236 
1237 	seq_puts(m, "synclink_gt driver\n");
1238 
1239 	info = slgt_device_list;
1240 	while( info ) {
1241 		line_info(m, info);
1242 		info = info->next_device;
1243 	}
1244 	return 0;
1245 }
1246 
1247 /*
1248  * return count of bytes in transmit buffer
1249  */
1250 static unsigned int chars_in_buffer(struct tty_struct *tty)
1251 {
1252 	struct slgt_info *info = tty->driver_data;
1253 	unsigned int count;
1254 	if (sanity_check(info, tty->name, "chars_in_buffer"))
1255 		return 0;
1256 	count = tbuf_bytes(info);
1257 	DBGINFO(("%s chars_in_buffer()=%u\n", info->device_name, count));
1258 	return count;
1259 }
1260 
1261 /*
1262  * signal remote device to throttle send data (our receive data)
1263  */
1264 static void throttle(struct tty_struct * tty)
1265 {
1266 	struct slgt_info *info = tty->driver_data;
1267 	unsigned long flags;
1268 
1269 	if (sanity_check(info, tty->name, "throttle"))
1270 		return;
1271 	DBGINFO(("%s throttle\n", info->device_name));
1272 	if (I_IXOFF(tty))
1273 		send_xchar(tty, STOP_CHAR(tty));
1274 	if (C_CRTSCTS(tty)) {
1275 		spin_lock_irqsave(&info->lock,flags);
1276 		info->signals &= ~SerialSignal_RTS;
1277 		set_gtsignals(info);
1278 		spin_unlock_irqrestore(&info->lock,flags);
1279 	}
1280 }
1281 
1282 /*
1283  * signal remote device to stop throttling send data (our receive data)
1284  */
1285 static void unthrottle(struct tty_struct * tty)
1286 {
1287 	struct slgt_info *info = tty->driver_data;
1288 	unsigned long flags;
1289 
1290 	if (sanity_check(info, tty->name, "unthrottle"))
1291 		return;
1292 	DBGINFO(("%s unthrottle\n", info->device_name));
1293 	if (I_IXOFF(tty)) {
1294 		if (info->x_char)
1295 			info->x_char = 0;
1296 		else
1297 			send_xchar(tty, START_CHAR(tty));
1298 	}
1299 	if (C_CRTSCTS(tty)) {
1300 		spin_lock_irqsave(&info->lock,flags);
1301 		info->signals |= SerialSignal_RTS;
1302 		set_gtsignals(info);
1303 		spin_unlock_irqrestore(&info->lock,flags);
1304 	}
1305 }
1306 
1307 /*
1308  * set or clear transmit break condition
1309  * break_state	-1=set break condition, 0=clear
1310  */
1311 static int set_break(struct tty_struct *tty, int break_state)
1312 {
1313 	struct slgt_info *info = tty->driver_data;
1314 	unsigned short value;
1315 	unsigned long flags;
1316 
1317 	if (sanity_check(info, tty->name, "set_break"))
1318 		return -EINVAL;
1319 	DBGINFO(("%s set_break(%d)\n", info->device_name, break_state));
1320 
1321 	spin_lock_irqsave(&info->lock,flags);
1322 	value = rd_reg16(info, TCR);
1323  	if (break_state == -1)
1324 		value |= BIT6;
1325 	else
1326 		value &= ~BIT6;
1327 	wr_reg16(info, TCR, value);
1328 	spin_unlock_irqrestore(&info->lock,flags);
1329 	return 0;
1330 }
1331 
1332 #if SYNCLINK_GENERIC_HDLC
1333 
1334 /**
1335  * hdlcdev_attach - called by generic HDLC layer when protocol selected (PPP, frame relay, etc.)
1336  * @dev:      pointer to network device structure
1337  * @encoding: serial encoding setting
1338  * @parity:   FCS setting
1339  *
1340  * Set encoding and frame check sequence (FCS) options.
1341  *
1342  * Return: 0 if success, otherwise error code
1343  */
1344 static int hdlcdev_attach(struct net_device *dev, unsigned short encoding,
1345 			  unsigned short parity)
1346 {
1347 	struct slgt_info *info = dev_to_port(dev);
1348 	unsigned char  new_encoding;
1349 	unsigned short new_crctype;
1350 
1351 	/* return error if TTY interface open */
1352 	if (info->port.count)
1353 		return -EBUSY;
1354 
1355 	DBGINFO(("%s hdlcdev_attach\n", info->device_name));
1356 
1357 	switch (encoding)
1358 	{
1359 	case ENCODING_NRZ:        new_encoding = HDLC_ENCODING_NRZ; break;
1360 	case ENCODING_NRZI:       new_encoding = HDLC_ENCODING_NRZI_SPACE; break;
1361 	case ENCODING_FM_MARK:    new_encoding = HDLC_ENCODING_BIPHASE_MARK; break;
1362 	case ENCODING_FM_SPACE:   new_encoding = HDLC_ENCODING_BIPHASE_SPACE; break;
1363 	case ENCODING_MANCHESTER: new_encoding = HDLC_ENCODING_BIPHASE_LEVEL; break;
1364 	default: return -EINVAL;
1365 	}
1366 
1367 	switch (parity)
1368 	{
1369 	case PARITY_NONE:            new_crctype = HDLC_CRC_NONE; break;
1370 	case PARITY_CRC16_PR1_CCITT: new_crctype = HDLC_CRC_16_CCITT; break;
1371 	case PARITY_CRC32_PR1_CCITT: new_crctype = HDLC_CRC_32_CCITT; break;
1372 	default: return -EINVAL;
1373 	}
1374 
1375 	info->params.encoding = new_encoding;
1376 	info->params.crc_type = new_crctype;
1377 
1378 	/* if network interface up, reprogram hardware */
1379 	if (info->netcount)
1380 		program_hw(info);
1381 
1382 	return 0;
1383 }
1384 
1385 /**
1386  * hdlcdev_xmit - called by generic HDLC layer to send a frame
1387  * @skb: socket buffer containing HDLC frame
1388  * @dev: pointer to network device structure
1389  */
1390 static netdev_tx_t hdlcdev_xmit(struct sk_buff *skb,
1391 				      struct net_device *dev)
1392 {
1393 	struct slgt_info *info = dev_to_port(dev);
1394 	unsigned long flags;
1395 
1396 	DBGINFO(("%s hdlc_xmit\n", dev->name));
1397 
1398 	if (!skb->len)
1399 		return NETDEV_TX_OK;
1400 
1401 	/* stop sending until this frame completes */
1402 	netif_stop_queue(dev);
1403 
1404 	/* update network statistics */
1405 	dev->stats.tx_packets++;
1406 	dev->stats.tx_bytes += skb->len;
1407 
1408 	/* save start time for transmit timeout detection */
1409 	netif_trans_update(dev);
1410 
1411 	spin_lock_irqsave(&info->lock, flags);
1412 	tx_load(info, skb->data, skb->len);
1413 	spin_unlock_irqrestore(&info->lock, flags);
1414 
1415 	/* done with socket buffer, so free it */
1416 	dev_kfree_skb(skb);
1417 
1418 	return NETDEV_TX_OK;
1419 }
1420 
1421 /**
1422  * hdlcdev_open - called by network layer when interface enabled
1423  * @dev: pointer to network device structure
1424  *
1425  * Claim resources and initialize hardware.
1426  *
1427  * Return: 0 if success, otherwise error code
1428  */
1429 static int hdlcdev_open(struct net_device *dev)
1430 {
1431 	struct slgt_info *info = dev_to_port(dev);
1432 	int rc;
1433 	unsigned long flags;
1434 
1435 	DBGINFO(("%s hdlcdev_open\n", dev->name));
1436 
1437 	/* arbitrate between network and tty opens */
1438 	spin_lock_irqsave(&info->netlock, flags);
1439 	if (info->port.count != 0 || info->netcount != 0) {
1440 		DBGINFO(("%s hdlc_open busy\n", dev->name));
1441 		spin_unlock_irqrestore(&info->netlock, flags);
1442 		return -EBUSY;
1443 	}
1444 	info->netcount=1;
1445 	spin_unlock_irqrestore(&info->netlock, flags);
1446 
1447 	/* claim resources and init adapter */
1448 	if ((rc = startup(info)) != 0) {
1449 		spin_lock_irqsave(&info->netlock, flags);
1450 		info->netcount=0;
1451 		spin_unlock_irqrestore(&info->netlock, flags);
1452 		return rc;
1453 	}
1454 
1455 	/* generic HDLC layer open processing */
1456 	rc = hdlc_open(dev);
1457 	if (rc) {
1458 		shutdown(info);
1459 		spin_lock_irqsave(&info->netlock, flags);
1460 		info->netcount = 0;
1461 		spin_unlock_irqrestore(&info->netlock, flags);
1462 		return rc;
1463 	}
1464 
1465 	/* assert RTS and DTR, apply hardware settings */
1466 	info->signals |= SerialSignal_RTS | SerialSignal_DTR;
1467 	program_hw(info);
1468 
1469 	/* enable network layer transmit */
1470 	netif_trans_update(dev);
1471 	netif_start_queue(dev);
1472 
1473 	/* inform generic HDLC layer of current DCD status */
1474 	spin_lock_irqsave(&info->lock, flags);
1475 	get_gtsignals(info);
1476 	spin_unlock_irqrestore(&info->lock, flags);
1477 	if (info->signals & SerialSignal_DCD)
1478 		netif_carrier_on(dev);
1479 	else
1480 		netif_carrier_off(dev);
1481 	return 0;
1482 }
1483 
1484 /**
1485  * hdlcdev_close - called by network layer when interface is disabled
1486  * @dev:  pointer to network device structure
1487  *
1488  * Shutdown hardware and release resources.
1489  *
1490  * Return: 0 if success, otherwise error code
1491  */
1492 static int hdlcdev_close(struct net_device *dev)
1493 {
1494 	struct slgt_info *info = dev_to_port(dev);
1495 	unsigned long flags;
1496 
1497 	DBGINFO(("%s hdlcdev_close\n", dev->name));
1498 
1499 	netif_stop_queue(dev);
1500 
1501 	/* shutdown adapter and release resources */
1502 	shutdown(info);
1503 
1504 	hdlc_close(dev);
1505 
1506 	spin_lock_irqsave(&info->netlock, flags);
1507 	info->netcount=0;
1508 	spin_unlock_irqrestore(&info->netlock, flags);
1509 
1510 	return 0;
1511 }
1512 
1513 /**
1514  * hdlcdev_ioctl - called by network layer to process IOCTL call to network device
1515  * @dev: pointer to network device structure
1516  * @ifr: pointer to network interface request structure
1517  * @cmd: IOCTL command code
1518  *
1519  * Return: 0 if success, otherwise error code
1520  */
1521 static int hdlcdev_ioctl(struct net_device *dev, struct if_settings *ifs)
1522 {
1523 	const size_t size = sizeof(sync_serial_settings);
1524 	sync_serial_settings new_line;
1525 	sync_serial_settings __user *line = ifs->ifs_ifsu.sync;
1526 	struct slgt_info *info = dev_to_port(dev);
1527 	unsigned int flags;
1528 
1529 	DBGINFO(("%s hdlcdev_ioctl\n", dev->name));
1530 
1531 	/* return error if TTY interface open */
1532 	if (info->port.count)
1533 		return -EBUSY;
1534 
1535 	memset(&new_line, 0, sizeof(new_line));
1536 
1537 	switch (ifs->type) {
1538 	case IF_GET_IFACE: /* return current sync_serial_settings */
1539 
1540 		ifs->type = IF_IFACE_SYNC_SERIAL;
1541 		if (ifs->size < size) {
1542 			ifs->size = size; /* data size wanted */
1543 			return -ENOBUFS;
1544 		}
1545 
1546 		flags = info->params.flags & (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
1547 					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
1548 					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
1549 					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
1550 
1551 		switch (flags){
1552 		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN): new_line.clock_type = CLOCK_EXT; break;
1553 		case (HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_INT; break;
1554 		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_TXINT; break;
1555 		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN): new_line.clock_type = CLOCK_TXFROMRX; break;
1556 		default: new_line.clock_type = CLOCK_DEFAULT;
1557 		}
1558 
1559 		new_line.clock_rate = info->params.clock_speed;
1560 		new_line.loopback   = info->params.loopback ? 1:0;
1561 
1562 		if (copy_to_user(line, &new_line, size))
1563 			return -EFAULT;
1564 		return 0;
1565 
1566 	case IF_IFACE_SYNC_SERIAL: /* set sync_serial_settings */
1567 
1568 		if(!capable(CAP_NET_ADMIN))
1569 			return -EPERM;
1570 		if (copy_from_user(&new_line, line, size))
1571 			return -EFAULT;
1572 
1573 		switch (new_line.clock_type)
1574 		{
1575 		case CLOCK_EXT:      flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN; break;
1576 		case CLOCK_TXFROMRX: flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN; break;
1577 		case CLOCK_INT:      flags = HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG;    break;
1578 		case CLOCK_TXINT:    flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG;    break;
1579 		case CLOCK_DEFAULT:  flags = info->params.flags &
1580 					     (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
1581 					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
1582 					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
1583 					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN); break;
1584 		default: return -EINVAL;
1585 		}
1586 
1587 		if (new_line.loopback != 0 && new_line.loopback != 1)
1588 			return -EINVAL;
1589 
1590 		info->params.flags &= ~(HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
1591 					HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
1592 					HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
1593 					HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
1594 		info->params.flags |= flags;
1595 
1596 		info->params.loopback = new_line.loopback;
1597 
1598 		if (flags & (HDLC_FLAG_RXC_BRG | HDLC_FLAG_TXC_BRG))
1599 			info->params.clock_speed = new_line.clock_rate;
1600 		else
1601 			info->params.clock_speed = 0;
1602 
1603 		/* if network interface up, reprogram hardware */
1604 		if (info->netcount)
1605 			program_hw(info);
1606 		return 0;
1607 
1608 	default:
1609 		return hdlc_ioctl(dev, ifs);
1610 	}
1611 }
1612 
1613 /**
1614  * hdlcdev_tx_timeout - called by network layer when transmit timeout is detected
1615  * @dev: pointer to network device structure
1616  * @txqueue: unused
1617  */
1618 static void hdlcdev_tx_timeout(struct net_device *dev, unsigned int txqueue)
1619 {
1620 	struct slgt_info *info = dev_to_port(dev);
1621 	unsigned long flags;
1622 
1623 	DBGINFO(("%s hdlcdev_tx_timeout\n", dev->name));
1624 
1625 	dev->stats.tx_errors++;
1626 	dev->stats.tx_aborted_errors++;
1627 
1628 	spin_lock_irqsave(&info->lock,flags);
1629 	tx_stop(info);
1630 	spin_unlock_irqrestore(&info->lock,flags);
1631 
1632 	netif_wake_queue(dev);
1633 }
1634 
1635 /**
1636  * hdlcdev_tx_done - called by device driver when transmit completes
1637  * @info: pointer to device instance information
1638  *
1639  * Reenable network layer transmit if stopped.
1640  */
1641 static void hdlcdev_tx_done(struct slgt_info *info)
1642 {
1643 	if (netif_queue_stopped(info->netdev))
1644 		netif_wake_queue(info->netdev);
1645 }
1646 
1647 /**
1648  * hdlcdev_rx - called by device driver when frame received
1649  * @info: pointer to device instance information
1650  * @buf:  pointer to buffer contianing frame data
1651  * @size: count of data bytes in buf
1652  *
1653  * Pass frame to network layer.
1654  */
1655 static void hdlcdev_rx(struct slgt_info *info, char *buf, int size)
1656 {
1657 	struct sk_buff *skb = dev_alloc_skb(size);
1658 	struct net_device *dev = info->netdev;
1659 
1660 	DBGINFO(("%s hdlcdev_rx\n", dev->name));
1661 
1662 	if (skb == NULL) {
1663 		DBGERR(("%s: can't alloc skb, drop packet\n", dev->name));
1664 		dev->stats.rx_dropped++;
1665 		return;
1666 	}
1667 
1668 	skb_put_data(skb, buf, size);
1669 
1670 	skb->protocol = hdlc_type_trans(skb, dev);
1671 
1672 	dev->stats.rx_packets++;
1673 	dev->stats.rx_bytes += size;
1674 
1675 	netif_rx(skb);
1676 }
1677 
1678 static const struct net_device_ops hdlcdev_ops = {
1679 	.ndo_open       = hdlcdev_open,
1680 	.ndo_stop       = hdlcdev_close,
1681 	.ndo_start_xmit = hdlc_start_xmit,
1682 	.ndo_siocwandev = hdlcdev_ioctl,
1683 	.ndo_tx_timeout = hdlcdev_tx_timeout,
1684 };
1685 
1686 /**
1687  * hdlcdev_init - called by device driver when adding device instance
1688  * @info: pointer to device instance information
1689  *
1690  * Do generic HDLC initialization.
1691  *
1692  * Return: 0 if success, otherwise error code
1693  */
1694 static int hdlcdev_init(struct slgt_info *info)
1695 {
1696 	int rc;
1697 	struct net_device *dev;
1698 	hdlc_device *hdlc;
1699 
1700 	/* allocate and initialize network and HDLC layer objects */
1701 
1702 	dev = alloc_hdlcdev(info);
1703 	if (!dev) {
1704 		printk(KERN_ERR "%s hdlc device alloc failure\n", info->device_name);
1705 		return -ENOMEM;
1706 	}
1707 
1708 	/* for network layer reporting purposes only */
1709 	dev->mem_start = info->phys_reg_addr;
1710 	dev->mem_end   = info->phys_reg_addr + SLGT_REG_SIZE - 1;
1711 	dev->irq       = info->irq_level;
1712 
1713 	/* network layer callbacks and settings */
1714 	dev->netdev_ops	    = &hdlcdev_ops;
1715 	dev->watchdog_timeo = 10 * HZ;
1716 	dev->tx_queue_len   = 50;
1717 
1718 	/* generic HDLC layer callbacks and settings */
1719 	hdlc         = dev_to_hdlc(dev);
1720 	hdlc->attach = hdlcdev_attach;
1721 	hdlc->xmit   = hdlcdev_xmit;
1722 
1723 	/* register objects with HDLC layer */
1724 	rc = register_hdlc_device(dev);
1725 	if (rc) {
1726 		printk(KERN_WARNING "%s:unable to register hdlc device\n",__FILE__);
1727 		free_netdev(dev);
1728 		return rc;
1729 	}
1730 
1731 	info->netdev = dev;
1732 	return 0;
1733 }
1734 
1735 /**
1736  * hdlcdev_exit - called by device driver when removing device instance
1737  * @info: pointer to device instance information
1738  *
1739  * Do generic HDLC cleanup.
1740  */
1741 static void hdlcdev_exit(struct slgt_info *info)
1742 {
1743 	if (!info->netdev)
1744 		return;
1745 	unregister_hdlc_device(info->netdev);
1746 	free_netdev(info->netdev);
1747 	info->netdev = NULL;
1748 }
1749 
1750 #endif /* ifdef CONFIG_HDLC */
1751 
1752 /*
1753  * get async data from rx DMA buffers
1754  */
1755 static void rx_async(struct slgt_info *info)
1756 {
1757  	struct mgsl_icount *icount = &info->icount;
1758 	unsigned int start, end;
1759 	unsigned char *p;
1760 	unsigned char status;
1761 	struct slgt_desc *bufs = info->rbufs;
1762 	int i, count;
1763 	int chars = 0;
1764 	int stat;
1765 	unsigned char ch;
1766 
1767 	start = end = info->rbuf_current;
1768 
1769 	while(desc_complete(bufs[end])) {
1770 		count = desc_count(bufs[end]) - info->rbuf_index;
1771 		p     = bufs[end].buf + info->rbuf_index;
1772 
1773 		DBGISR(("%s rx_async count=%d\n", info->device_name, count));
1774 		DBGDATA(info, p, count, "rx");
1775 
1776 		for(i=0 ; i < count; i+=2, p+=2) {
1777 			ch = *p;
1778 			icount->rx++;
1779 
1780 			stat = 0;
1781 
1782 			status = *(p + 1) & (BIT1 + BIT0);
1783 			if (status) {
1784 				if (status & BIT1)
1785 					icount->parity++;
1786 				else if (status & BIT0)
1787 					icount->frame++;
1788 				/* discard char if tty control flags say so */
1789 				if (status & info->ignore_status_mask)
1790 					continue;
1791 				if (status & BIT1)
1792 					stat = TTY_PARITY;
1793 				else if (status & BIT0)
1794 					stat = TTY_FRAME;
1795 			}
1796 			tty_insert_flip_char(&info->port, ch, stat);
1797 			chars++;
1798 		}
1799 
1800 		if (i < count) {
1801 			/* receive buffer not completed */
1802 			info->rbuf_index += i;
1803 			mod_timer(&info->rx_timer, jiffies + 1);
1804 			break;
1805 		}
1806 
1807 		info->rbuf_index = 0;
1808 		free_rbufs(info, end, end);
1809 
1810 		if (++end == info->rbuf_count)
1811 			end = 0;
1812 
1813 		/* if entire list searched then no frame available */
1814 		if (end == start)
1815 			break;
1816 	}
1817 
1818 	if (chars)
1819 		tty_flip_buffer_push(&info->port);
1820 }
1821 
1822 /*
1823  * return next bottom half action to perform
1824  */
1825 static int bh_action(struct slgt_info *info)
1826 {
1827 	unsigned long flags;
1828 	int rc;
1829 
1830 	spin_lock_irqsave(&info->lock,flags);
1831 
1832 	if (info->pending_bh & BH_RECEIVE) {
1833 		info->pending_bh &= ~BH_RECEIVE;
1834 		rc = BH_RECEIVE;
1835 	} else if (info->pending_bh & BH_TRANSMIT) {
1836 		info->pending_bh &= ~BH_TRANSMIT;
1837 		rc = BH_TRANSMIT;
1838 	} else if (info->pending_bh & BH_STATUS) {
1839 		info->pending_bh &= ~BH_STATUS;
1840 		rc = BH_STATUS;
1841 	} else {
1842 		/* Mark BH routine as complete */
1843 		info->bh_running = false;
1844 		info->bh_requested = false;
1845 		rc = 0;
1846 	}
1847 
1848 	spin_unlock_irqrestore(&info->lock,flags);
1849 
1850 	return rc;
1851 }
1852 
1853 /*
1854  * perform bottom half processing
1855  */
1856 static void bh_handler(struct work_struct *work)
1857 {
1858 	struct slgt_info *info = container_of(work, struct slgt_info, task);
1859 	int action;
1860 
1861 	info->bh_running = true;
1862 
1863 	while((action = bh_action(info))) {
1864 		switch (action) {
1865 		case BH_RECEIVE:
1866 			DBGBH(("%s bh receive\n", info->device_name));
1867 			switch(info->params.mode) {
1868 			case MGSL_MODE_ASYNC:
1869 				rx_async(info);
1870 				break;
1871 			case MGSL_MODE_HDLC:
1872 				while(rx_get_frame(info));
1873 				break;
1874 			case MGSL_MODE_RAW:
1875 			case MGSL_MODE_MONOSYNC:
1876 			case MGSL_MODE_BISYNC:
1877 			case MGSL_MODE_XSYNC:
1878 				while(rx_get_buf(info));
1879 				break;
1880 			}
1881 			/* restart receiver if rx DMA buffers exhausted */
1882 			if (info->rx_restart)
1883 				rx_start(info);
1884 			break;
1885 		case BH_TRANSMIT:
1886 			bh_transmit(info);
1887 			break;
1888 		case BH_STATUS:
1889 			DBGBH(("%s bh status\n", info->device_name));
1890 			info->ri_chkcount = 0;
1891 			info->dsr_chkcount = 0;
1892 			info->dcd_chkcount = 0;
1893 			info->cts_chkcount = 0;
1894 			break;
1895 		default:
1896 			DBGBH(("%s unknown action\n", info->device_name));
1897 			break;
1898 		}
1899 	}
1900 	DBGBH(("%s bh_handler exit\n", info->device_name));
1901 }
1902 
1903 static void bh_transmit(struct slgt_info *info)
1904 {
1905 	struct tty_struct *tty = info->port.tty;
1906 
1907 	DBGBH(("%s bh_transmit\n", info->device_name));
1908 	if (tty)
1909 		tty_wakeup(tty);
1910 }
1911 
1912 static void dsr_change(struct slgt_info *info, unsigned short status)
1913 {
1914 	if (status & BIT3) {
1915 		info->signals |= SerialSignal_DSR;
1916 		info->input_signal_events.dsr_up++;
1917 	} else {
1918 		info->signals &= ~SerialSignal_DSR;
1919 		info->input_signal_events.dsr_down++;
1920 	}
1921 	DBGISR(("dsr_change %s signals=%04X\n", info->device_name, info->signals));
1922 	if ((info->dsr_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
1923 		slgt_irq_off(info, IRQ_DSR);
1924 		return;
1925 	}
1926 	info->icount.dsr++;
1927 	wake_up_interruptible(&info->status_event_wait_q);
1928 	wake_up_interruptible(&info->event_wait_q);
1929 	info->pending_bh |= BH_STATUS;
1930 }
1931 
1932 static void cts_change(struct slgt_info *info, unsigned short status)
1933 {
1934 	if (status & BIT2) {
1935 		info->signals |= SerialSignal_CTS;
1936 		info->input_signal_events.cts_up++;
1937 	} else {
1938 		info->signals &= ~SerialSignal_CTS;
1939 		info->input_signal_events.cts_down++;
1940 	}
1941 	DBGISR(("cts_change %s signals=%04X\n", info->device_name, info->signals));
1942 	if ((info->cts_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
1943 		slgt_irq_off(info, IRQ_CTS);
1944 		return;
1945 	}
1946 	info->icount.cts++;
1947 	wake_up_interruptible(&info->status_event_wait_q);
1948 	wake_up_interruptible(&info->event_wait_q);
1949 	info->pending_bh |= BH_STATUS;
1950 
1951 	if (tty_port_cts_enabled(&info->port)) {
1952 		if (info->port.tty) {
1953 			if (info->port.tty->hw_stopped) {
1954 				if (info->signals & SerialSignal_CTS) {
1955 					info->port.tty->hw_stopped = false;
1956 					info->pending_bh |= BH_TRANSMIT;
1957 					return;
1958 				}
1959 			} else {
1960 				if (!(info->signals & SerialSignal_CTS))
1961 					info->port.tty->hw_stopped = true;
1962 			}
1963 		}
1964 	}
1965 }
1966 
1967 static void dcd_change(struct slgt_info *info, unsigned short status)
1968 {
1969 	if (status & BIT1) {
1970 		info->signals |= SerialSignal_DCD;
1971 		info->input_signal_events.dcd_up++;
1972 	} else {
1973 		info->signals &= ~SerialSignal_DCD;
1974 		info->input_signal_events.dcd_down++;
1975 	}
1976 	DBGISR(("dcd_change %s signals=%04X\n", info->device_name, info->signals));
1977 	if ((info->dcd_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
1978 		slgt_irq_off(info, IRQ_DCD);
1979 		return;
1980 	}
1981 	info->icount.dcd++;
1982 #if SYNCLINK_GENERIC_HDLC
1983 	if (info->netcount) {
1984 		if (info->signals & SerialSignal_DCD)
1985 			netif_carrier_on(info->netdev);
1986 		else
1987 			netif_carrier_off(info->netdev);
1988 	}
1989 #endif
1990 	wake_up_interruptible(&info->status_event_wait_q);
1991 	wake_up_interruptible(&info->event_wait_q);
1992 	info->pending_bh |= BH_STATUS;
1993 
1994 	if (tty_port_check_carrier(&info->port)) {
1995 		if (info->signals & SerialSignal_DCD)
1996 			wake_up_interruptible(&info->port.open_wait);
1997 		else {
1998 			if (info->port.tty)
1999 				tty_hangup(info->port.tty);
2000 		}
2001 	}
2002 }
2003 
2004 static void ri_change(struct slgt_info *info, unsigned short status)
2005 {
2006 	if (status & BIT0) {
2007 		info->signals |= SerialSignal_RI;
2008 		info->input_signal_events.ri_up++;
2009 	} else {
2010 		info->signals &= ~SerialSignal_RI;
2011 		info->input_signal_events.ri_down++;
2012 	}
2013 	DBGISR(("ri_change %s signals=%04X\n", info->device_name, info->signals));
2014 	if ((info->ri_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
2015 		slgt_irq_off(info, IRQ_RI);
2016 		return;
2017 	}
2018 	info->icount.rng++;
2019 	wake_up_interruptible(&info->status_event_wait_q);
2020 	wake_up_interruptible(&info->event_wait_q);
2021 	info->pending_bh |= BH_STATUS;
2022 }
2023 
2024 static void isr_rxdata(struct slgt_info *info)
2025 {
2026 	unsigned int count = info->rbuf_fill_count;
2027 	unsigned int i = info->rbuf_fill_index;
2028 	unsigned short reg;
2029 
2030 	while (rd_reg16(info, SSR) & IRQ_RXDATA) {
2031 		reg = rd_reg16(info, RDR);
2032 		DBGISR(("isr_rxdata %s RDR=%04X\n", info->device_name, reg));
2033 		if (desc_complete(info->rbufs[i])) {
2034 			/* all buffers full */
2035 			rx_stop(info);
2036 			info->rx_restart = true;
2037 			continue;
2038 		}
2039 		info->rbufs[i].buf[count++] = (unsigned char)reg;
2040 		/* async mode saves status byte to buffer for each data byte */
2041 		if (info->params.mode == MGSL_MODE_ASYNC)
2042 			info->rbufs[i].buf[count++] = (unsigned char)(reg >> 8);
2043 		if (count == info->rbuf_fill_level || (reg & BIT10)) {
2044 			/* buffer full or end of frame */
2045 			set_desc_count(info->rbufs[i], count);
2046 			set_desc_status(info->rbufs[i], BIT15 | (reg >> 8));
2047 			info->rbuf_fill_count = count = 0;
2048 			if (++i == info->rbuf_count)
2049 				i = 0;
2050 			info->pending_bh |= BH_RECEIVE;
2051 		}
2052 	}
2053 
2054 	info->rbuf_fill_index = i;
2055 	info->rbuf_fill_count = count;
2056 }
2057 
2058 static void isr_serial(struct slgt_info *info)
2059 {
2060 	unsigned short status = rd_reg16(info, SSR);
2061 
2062 	DBGISR(("%s isr_serial status=%04X\n", info->device_name, status));
2063 
2064 	wr_reg16(info, SSR, status); /* clear pending */
2065 
2066 	info->irq_occurred = true;
2067 
2068 	if (info->params.mode == MGSL_MODE_ASYNC) {
2069 		if (status & IRQ_TXIDLE) {
2070 			if (info->tx_active)
2071 				isr_txeom(info, status);
2072 		}
2073 		if (info->rx_pio && (status & IRQ_RXDATA))
2074 			isr_rxdata(info);
2075 		if ((status & IRQ_RXBREAK) && (status & RXBREAK)) {
2076 			info->icount.brk++;
2077 			/* process break detection if tty control allows */
2078 			if (info->port.tty) {
2079 				if (!(status & info->ignore_status_mask)) {
2080 					if (info->read_status_mask & MASK_BREAK) {
2081 						tty_insert_flip_char(&info->port, 0, TTY_BREAK);
2082 						if (info->port.flags & ASYNC_SAK)
2083 							do_SAK(info->port.tty);
2084 					}
2085 				}
2086 			}
2087 		}
2088 	} else {
2089 		if (status & (IRQ_TXIDLE + IRQ_TXUNDER))
2090 			isr_txeom(info, status);
2091 		if (info->rx_pio && (status & IRQ_RXDATA))
2092 			isr_rxdata(info);
2093 		if (status & IRQ_RXIDLE) {
2094 			if (status & RXIDLE)
2095 				info->icount.rxidle++;
2096 			else
2097 				info->icount.exithunt++;
2098 			wake_up_interruptible(&info->event_wait_q);
2099 		}
2100 
2101 		if (status & IRQ_RXOVER)
2102 			rx_start(info);
2103 	}
2104 
2105 	if (status & IRQ_DSR)
2106 		dsr_change(info, status);
2107 	if (status & IRQ_CTS)
2108 		cts_change(info, status);
2109 	if (status & IRQ_DCD)
2110 		dcd_change(info, status);
2111 	if (status & IRQ_RI)
2112 		ri_change(info, status);
2113 }
2114 
2115 static void isr_rdma(struct slgt_info *info)
2116 {
2117 	unsigned int status = rd_reg32(info, RDCSR);
2118 
2119 	DBGISR(("%s isr_rdma status=%08x\n", info->device_name, status));
2120 
2121 	/* RDCSR (rx DMA control/status)
2122 	 *
2123 	 * 31..07  reserved
2124 	 * 06      save status byte to DMA buffer
2125 	 * 05      error
2126 	 * 04      eol (end of list)
2127 	 * 03      eob (end of buffer)
2128 	 * 02      IRQ enable
2129 	 * 01      reset
2130 	 * 00      enable
2131 	 */
2132 	wr_reg32(info, RDCSR, status);	/* clear pending */
2133 
2134 	if (status & (BIT5 + BIT4)) {
2135 		DBGISR(("%s isr_rdma rx_restart=1\n", info->device_name));
2136 		info->rx_restart = true;
2137 	}
2138 	info->pending_bh |= BH_RECEIVE;
2139 }
2140 
2141 static void isr_tdma(struct slgt_info *info)
2142 {
2143 	unsigned int status = rd_reg32(info, TDCSR);
2144 
2145 	DBGISR(("%s isr_tdma status=%08x\n", info->device_name, status));
2146 
2147 	/* TDCSR (tx DMA control/status)
2148 	 *
2149 	 * 31..06  reserved
2150 	 * 05      error
2151 	 * 04      eol (end of list)
2152 	 * 03      eob (end of buffer)
2153 	 * 02      IRQ enable
2154 	 * 01      reset
2155 	 * 00      enable
2156 	 */
2157 	wr_reg32(info, TDCSR, status);	/* clear pending */
2158 
2159 	if (status & (BIT5 + BIT4 + BIT3)) {
2160 		// another transmit buffer has completed
2161 		// run bottom half to get more send data from user
2162 		info->pending_bh |= BH_TRANSMIT;
2163 	}
2164 }
2165 
2166 /*
2167  * return true if there are unsent tx DMA buffers, otherwise false
2168  *
2169  * if there are unsent buffers then info->tbuf_start
2170  * is set to index of first unsent buffer
2171  */
2172 static bool unsent_tbufs(struct slgt_info *info)
2173 {
2174 	unsigned int i = info->tbuf_current;
2175 	bool rc = false;
2176 
2177 	/*
2178 	 * search backwards from last loaded buffer (precedes tbuf_current)
2179 	 * for first unsent buffer (desc_count > 0)
2180 	 */
2181 
2182 	do {
2183 		if (i)
2184 			i--;
2185 		else
2186 			i = info->tbuf_count - 1;
2187 		if (!desc_count(info->tbufs[i]))
2188 			break;
2189 		info->tbuf_start = i;
2190 		rc = true;
2191 	} while (i != info->tbuf_current);
2192 
2193 	return rc;
2194 }
2195 
2196 static void isr_txeom(struct slgt_info *info, unsigned short status)
2197 {
2198 	DBGISR(("%s txeom status=%04x\n", info->device_name, status));
2199 
2200 	slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);
2201 	tdma_reset(info);
2202 	if (status & IRQ_TXUNDER) {
2203 		unsigned short val = rd_reg16(info, TCR);
2204 		wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
2205 		wr_reg16(info, TCR, val); /* clear reset bit */
2206 	}
2207 
2208 	if (info->tx_active) {
2209 		if (info->params.mode != MGSL_MODE_ASYNC) {
2210 			if (status & IRQ_TXUNDER)
2211 				info->icount.txunder++;
2212 			else if (status & IRQ_TXIDLE)
2213 				info->icount.txok++;
2214 		}
2215 
2216 		if (unsent_tbufs(info)) {
2217 			tx_start(info);
2218 			update_tx_timer(info);
2219 			return;
2220 		}
2221 		info->tx_active = false;
2222 
2223 		del_timer(&info->tx_timer);
2224 
2225 		if (info->params.mode != MGSL_MODE_ASYNC && info->drop_rts_on_tx_done) {
2226 			info->signals &= ~SerialSignal_RTS;
2227 			info->drop_rts_on_tx_done = false;
2228 			set_gtsignals(info);
2229 		}
2230 
2231 #if SYNCLINK_GENERIC_HDLC
2232 		if (info->netcount)
2233 			hdlcdev_tx_done(info);
2234 		else
2235 #endif
2236 		{
2237 			if (info->port.tty && (info->port.tty->flow.stopped || info->port.tty->hw_stopped)) {
2238 				tx_stop(info);
2239 				return;
2240 			}
2241 			info->pending_bh |= BH_TRANSMIT;
2242 		}
2243 	}
2244 }
2245 
2246 static void isr_gpio(struct slgt_info *info, unsigned int changed, unsigned int state)
2247 {
2248 	struct cond_wait *w, *prev;
2249 
2250 	/* wake processes waiting for specific transitions */
2251 	for (w = info->gpio_wait_q, prev = NULL ; w != NULL ; w = w->next) {
2252 		if (w->data & changed) {
2253 			w->data = state;
2254 			wake_up_interruptible(&w->q);
2255 			if (prev != NULL)
2256 				prev->next = w->next;
2257 			else
2258 				info->gpio_wait_q = w->next;
2259 		} else
2260 			prev = w;
2261 	}
2262 }
2263 
2264 /* interrupt service routine
2265  *
2266  * 	irq	interrupt number
2267  * 	dev_id	device ID supplied during interrupt registration
2268  */
2269 static irqreturn_t slgt_interrupt(int dummy, void *dev_id)
2270 {
2271 	struct slgt_info *info = dev_id;
2272 	unsigned int gsr;
2273 	unsigned int i;
2274 
2275 	DBGISR(("slgt_interrupt irq=%d entry\n", info->irq_level));
2276 
2277 	while((gsr = rd_reg32(info, GSR) & 0xffffff00)) {
2278 		DBGISR(("%s gsr=%08x\n", info->device_name, gsr));
2279 		info->irq_occurred = true;
2280 		for(i=0; i < info->port_count ; i++) {
2281 			if (info->port_array[i] == NULL)
2282 				continue;
2283 			spin_lock(&info->port_array[i]->lock);
2284 			if (gsr & (BIT8 << i))
2285 				isr_serial(info->port_array[i]);
2286 			if (gsr & (BIT16 << (i*2)))
2287 				isr_rdma(info->port_array[i]);
2288 			if (gsr & (BIT17 << (i*2)))
2289 				isr_tdma(info->port_array[i]);
2290 			spin_unlock(&info->port_array[i]->lock);
2291 		}
2292 	}
2293 
2294 	if (info->gpio_present) {
2295 		unsigned int state;
2296 		unsigned int changed;
2297 		spin_lock(&info->lock);
2298 		while ((changed = rd_reg32(info, IOSR)) != 0) {
2299 			DBGISR(("%s iosr=%08x\n", info->device_name, changed));
2300 			/* read latched state of GPIO signals */
2301 			state = rd_reg32(info, IOVR);
2302 			/* clear pending GPIO interrupt bits */
2303 			wr_reg32(info, IOSR, changed);
2304 			for (i=0 ; i < info->port_count ; i++) {
2305 				if (info->port_array[i] != NULL)
2306 					isr_gpio(info->port_array[i], changed, state);
2307 			}
2308 		}
2309 		spin_unlock(&info->lock);
2310 	}
2311 
2312 	for(i=0; i < info->port_count ; i++) {
2313 		struct slgt_info *port = info->port_array[i];
2314 		if (port == NULL)
2315 			continue;
2316 		spin_lock(&port->lock);
2317 		if ((port->port.count || port->netcount) &&
2318 		    port->pending_bh && !port->bh_running &&
2319 		    !port->bh_requested) {
2320 			DBGISR(("%s bh queued\n", port->device_name));
2321 			schedule_work(&port->task);
2322 			port->bh_requested = true;
2323 		}
2324 		spin_unlock(&port->lock);
2325 	}
2326 
2327 	DBGISR(("slgt_interrupt irq=%d exit\n", info->irq_level));
2328 	return IRQ_HANDLED;
2329 }
2330 
2331 static int startup(struct slgt_info *info)
2332 {
2333 	DBGINFO(("%s startup\n", info->device_name));
2334 
2335 	if (tty_port_initialized(&info->port))
2336 		return 0;
2337 
2338 	if (!info->tx_buf) {
2339 		info->tx_buf = kmalloc(info->max_frame_size, GFP_KERNEL);
2340 		if (!info->tx_buf) {
2341 			DBGERR(("%s can't allocate tx buffer\n", info->device_name));
2342 			return -ENOMEM;
2343 		}
2344 	}
2345 
2346 	info->pending_bh = 0;
2347 
2348 	memset(&info->icount, 0, sizeof(info->icount));
2349 
2350 	/* program hardware for current parameters */
2351 	change_params(info);
2352 
2353 	if (info->port.tty)
2354 		clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
2355 
2356 	tty_port_set_initialized(&info->port, true);
2357 
2358 	return 0;
2359 }
2360 
2361 /*
2362  *  called by close() and hangup() to shutdown hardware
2363  */
2364 static void shutdown(struct slgt_info *info)
2365 {
2366 	unsigned long flags;
2367 
2368 	if (!tty_port_initialized(&info->port))
2369 		return;
2370 
2371 	DBGINFO(("%s shutdown\n", info->device_name));
2372 
2373 	/* clear status wait queue because status changes */
2374 	/* can't happen after shutting down the hardware */
2375 	wake_up_interruptible(&info->status_event_wait_q);
2376 	wake_up_interruptible(&info->event_wait_q);
2377 
2378 	del_timer_sync(&info->tx_timer);
2379 	del_timer_sync(&info->rx_timer);
2380 
2381 	kfree(info->tx_buf);
2382 	info->tx_buf = NULL;
2383 
2384 	spin_lock_irqsave(&info->lock,flags);
2385 
2386 	tx_stop(info);
2387 	rx_stop(info);
2388 
2389 	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
2390 
2391  	if (!info->port.tty || info->port.tty->termios.c_cflag & HUPCL) {
2392 		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
2393 		set_gtsignals(info);
2394 	}
2395 
2396 	flush_cond_wait(&info->gpio_wait_q);
2397 
2398 	spin_unlock_irqrestore(&info->lock,flags);
2399 
2400 	if (info->port.tty)
2401 		set_bit(TTY_IO_ERROR, &info->port.tty->flags);
2402 
2403 	tty_port_set_initialized(&info->port, false);
2404 }
2405 
2406 static void program_hw(struct slgt_info *info)
2407 {
2408 	unsigned long flags;
2409 
2410 	spin_lock_irqsave(&info->lock,flags);
2411 
2412 	rx_stop(info);
2413 	tx_stop(info);
2414 
2415 	if (info->params.mode != MGSL_MODE_ASYNC ||
2416 	    info->netcount)
2417 		sync_mode(info);
2418 	else
2419 		async_mode(info);
2420 
2421 	set_gtsignals(info);
2422 
2423 	info->dcd_chkcount = 0;
2424 	info->cts_chkcount = 0;
2425 	info->ri_chkcount = 0;
2426 	info->dsr_chkcount = 0;
2427 
2428 	slgt_irq_on(info, IRQ_DCD | IRQ_CTS | IRQ_DSR | IRQ_RI);
2429 	get_gtsignals(info);
2430 
2431 	if (info->netcount ||
2432 	    (info->port.tty && info->port.tty->termios.c_cflag & CREAD))
2433 		rx_start(info);
2434 
2435 	spin_unlock_irqrestore(&info->lock,flags);
2436 }
2437 
2438 /*
2439  * reconfigure adapter based on new parameters
2440  */
2441 static void change_params(struct slgt_info *info)
2442 {
2443 	unsigned cflag;
2444 	int bits_per_char;
2445 
2446 	if (!info->port.tty)
2447 		return;
2448 	DBGINFO(("%s change_params\n", info->device_name));
2449 
2450 	cflag = info->port.tty->termios.c_cflag;
2451 
2452 	/* if B0 rate (hangup) specified then negate RTS and DTR */
2453 	/* otherwise assert RTS and DTR */
2454  	if (cflag & CBAUD)
2455 		info->signals |= SerialSignal_RTS | SerialSignal_DTR;
2456 	else
2457 		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
2458 
2459 	/* byte size and parity */
2460 
2461 	info->params.data_bits = tty_get_char_size(cflag);
2462 	info->params.stop_bits = (cflag & CSTOPB) ? 2 : 1;
2463 
2464 	if (cflag & PARENB)
2465 		info->params.parity = (cflag & PARODD) ? ASYNC_PARITY_ODD : ASYNC_PARITY_EVEN;
2466 	else
2467 		info->params.parity = ASYNC_PARITY_NONE;
2468 
2469 	/* calculate number of jiffies to transmit a full
2470 	 * FIFO (32 bytes) at specified data rate
2471 	 */
2472 	bits_per_char = info->params.data_bits +
2473 			info->params.stop_bits + 1;
2474 
2475 	info->params.data_rate = tty_get_baud_rate(info->port.tty);
2476 
2477 	if (info->params.data_rate) {
2478 		info->timeout = (32*HZ*bits_per_char) /
2479 				info->params.data_rate;
2480 	}
2481 	info->timeout += HZ/50;		/* Add .02 seconds of slop */
2482 
2483 	tty_port_set_cts_flow(&info->port, cflag & CRTSCTS);
2484 	tty_port_set_check_carrier(&info->port, ~cflag & CLOCAL);
2485 
2486 	/* process tty input control flags */
2487 
2488 	info->read_status_mask = IRQ_RXOVER;
2489 	if (I_INPCK(info->port.tty))
2490 		info->read_status_mask |= MASK_PARITY | MASK_FRAMING;
2491 	if (I_BRKINT(info->port.tty) || I_PARMRK(info->port.tty))
2492 		info->read_status_mask |= MASK_BREAK;
2493 	if (I_IGNPAR(info->port.tty))
2494 		info->ignore_status_mask |= MASK_PARITY | MASK_FRAMING;
2495 	if (I_IGNBRK(info->port.tty)) {
2496 		info->ignore_status_mask |= MASK_BREAK;
2497 		/* If ignoring parity and break indicators, ignore
2498 		 * overruns too.  (For real raw support).
2499 		 */
2500 		if (I_IGNPAR(info->port.tty))
2501 			info->ignore_status_mask |= MASK_OVERRUN;
2502 	}
2503 
2504 	program_hw(info);
2505 }
2506 
2507 static int get_stats(struct slgt_info *info, struct mgsl_icount __user *user_icount)
2508 {
2509 	DBGINFO(("%s get_stats\n",  info->device_name));
2510 	if (!user_icount) {
2511 		memset(&info->icount, 0, sizeof(info->icount));
2512 	} else {
2513 		if (copy_to_user(user_icount, &info->icount, sizeof(struct mgsl_icount)))
2514 			return -EFAULT;
2515 	}
2516 	return 0;
2517 }
2518 
2519 static int get_params(struct slgt_info *info, MGSL_PARAMS __user *user_params)
2520 {
2521 	DBGINFO(("%s get_params\n", info->device_name));
2522 	if (copy_to_user(user_params, &info->params, sizeof(MGSL_PARAMS)))
2523 		return -EFAULT;
2524 	return 0;
2525 }
2526 
2527 static int set_params(struct slgt_info *info, MGSL_PARAMS __user *new_params)
2528 {
2529  	unsigned long flags;
2530 	MGSL_PARAMS tmp_params;
2531 
2532 	DBGINFO(("%s set_params\n", info->device_name));
2533 	if (copy_from_user(&tmp_params, new_params, sizeof(MGSL_PARAMS)))
2534 		return -EFAULT;
2535 
2536 	spin_lock_irqsave(&info->lock, flags);
2537 	if (tmp_params.mode == MGSL_MODE_BASE_CLOCK)
2538 		info->base_clock = tmp_params.clock_speed;
2539 	else
2540 		memcpy(&info->params, &tmp_params, sizeof(MGSL_PARAMS));
2541 	spin_unlock_irqrestore(&info->lock, flags);
2542 
2543 	program_hw(info);
2544 
2545 	return 0;
2546 }
2547 
2548 static int get_txidle(struct slgt_info *info, int __user *idle_mode)
2549 {
2550 	DBGINFO(("%s get_txidle=%d\n", info->device_name, info->idle_mode));
2551 	if (put_user(info->idle_mode, idle_mode))
2552 		return -EFAULT;
2553 	return 0;
2554 }
2555 
2556 static int set_txidle(struct slgt_info *info, int idle_mode)
2557 {
2558  	unsigned long flags;
2559 	DBGINFO(("%s set_txidle(%d)\n", info->device_name, idle_mode));
2560 	spin_lock_irqsave(&info->lock,flags);
2561 	info->idle_mode = idle_mode;
2562 	if (info->params.mode != MGSL_MODE_ASYNC)
2563 		tx_set_idle(info);
2564 	spin_unlock_irqrestore(&info->lock,flags);
2565 	return 0;
2566 }
2567 
2568 static int tx_enable(struct slgt_info *info, int enable)
2569 {
2570  	unsigned long flags;
2571 	DBGINFO(("%s tx_enable(%d)\n", info->device_name, enable));
2572 	spin_lock_irqsave(&info->lock,flags);
2573 	if (enable) {
2574 		if (!info->tx_enabled)
2575 			tx_start(info);
2576 	} else {
2577 		if (info->tx_enabled)
2578 			tx_stop(info);
2579 	}
2580 	spin_unlock_irqrestore(&info->lock,flags);
2581 	return 0;
2582 }
2583 
2584 /*
2585  * abort transmit HDLC frame
2586  */
2587 static int tx_abort(struct slgt_info *info)
2588 {
2589  	unsigned long flags;
2590 	DBGINFO(("%s tx_abort\n", info->device_name));
2591 	spin_lock_irqsave(&info->lock,flags);
2592 	tdma_reset(info);
2593 	spin_unlock_irqrestore(&info->lock,flags);
2594 	return 0;
2595 }
2596 
2597 static int rx_enable(struct slgt_info *info, int enable)
2598 {
2599  	unsigned long flags;
2600 	unsigned int rbuf_fill_level;
2601 	DBGINFO(("%s rx_enable(%08x)\n", info->device_name, enable));
2602 	spin_lock_irqsave(&info->lock,flags);
2603 	/*
2604 	 * enable[31..16] = receive DMA buffer fill level
2605 	 * 0 = noop (leave fill level unchanged)
2606 	 * fill level must be multiple of 4 and <= buffer size
2607 	 */
2608 	rbuf_fill_level = ((unsigned int)enable) >> 16;
2609 	if (rbuf_fill_level) {
2610 		if ((rbuf_fill_level > DMABUFSIZE) || (rbuf_fill_level % 4)) {
2611 			spin_unlock_irqrestore(&info->lock, flags);
2612 			return -EINVAL;
2613 		}
2614 		info->rbuf_fill_level = rbuf_fill_level;
2615 		if (rbuf_fill_level < 128)
2616 			info->rx_pio = 1; /* PIO mode */
2617 		else
2618 			info->rx_pio = 0; /* DMA mode */
2619 		rx_stop(info); /* restart receiver to use new fill level */
2620 	}
2621 
2622 	/*
2623 	 * enable[1..0] = receiver enable command
2624 	 * 0 = disable
2625 	 * 1 = enable
2626 	 * 2 = enable or force hunt mode if already enabled
2627 	 */
2628 	enable &= 3;
2629 	if (enable) {
2630 		if (!info->rx_enabled)
2631 			rx_start(info);
2632 		else if (enable == 2) {
2633 			/* force hunt mode (write 1 to RCR[3]) */
2634 			wr_reg16(info, RCR, rd_reg16(info, RCR) | BIT3);
2635 		}
2636 	} else {
2637 		if (info->rx_enabled)
2638 			rx_stop(info);
2639 	}
2640 	spin_unlock_irqrestore(&info->lock,flags);
2641 	return 0;
2642 }
2643 
2644 /*
2645  *  wait for specified event to occur
2646  */
2647 static int wait_mgsl_event(struct slgt_info *info, int __user *mask_ptr)
2648 {
2649  	unsigned long flags;
2650 	int s;
2651 	int rc=0;
2652 	struct mgsl_icount cprev, cnow;
2653 	int events;
2654 	int mask;
2655 	struct	_input_signal_events oldsigs, newsigs;
2656 	DECLARE_WAITQUEUE(wait, current);
2657 
2658 	if (get_user(mask, mask_ptr))
2659 		return -EFAULT;
2660 
2661 	DBGINFO(("%s wait_mgsl_event(%d)\n", info->device_name, mask));
2662 
2663 	spin_lock_irqsave(&info->lock,flags);
2664 
2665 	/* return immediately if state matches requested events */
2666 	get_gtsignals(info);
2667 	s = info->signals;
2668 
2669 	events = mask &
2670 		( ((s & SerialSignal_DSR) ? MgslEvent_DsrActive:MgslEvent_DsrInactive) +
2671  		  ((s & SerialSignal_DCD) ? MgslEvent_DcdActive:MgslEvent_DcdInactive) +
2672 		  ((s & SerialSignal_CTS) ? MgslEvent_CtsActive:MgslEvent_CtsInactive) +
2673 		  ((s & SerialSignal_RI)  ? MgslEvent_RiActive :MgslEvent_RiInactive) );
2674 	if (events) {
2675 		spin_unlock_irqrestore(&info->lock,flags);
2676 		goto exit;
2677 	}
2678 
2679 	/* save current irq counts */
2680 	cprev = info->icount;
2681 	oldsigs = info->input_signal_events;
2682 
2683 	/* enable hunt and idle irqs if needed */
2684 	if (mask & (MgslEvent_ExitHuntMode+MgslEvent_IdleReceived)) {
2685 		unsigned short val = rd_reg16(info, SCR);
2686 		if (!(val & IRQ_RXIDLE))
2687 			wr_reg16(info, SCR, (unsigned short)(val | IRQ_RXIDLE));
2688 	}
2689 
2690 	set_current_state(TASK_INTERRUPTIBLE);
2691 	add_wait_queue(&info->event_wait_q, &wait);
2692 
2693 	spin_unlock_irqrestore(&info->lock,flags);
2694 
2695 	for(;;) {
2696 		schedule();
2697 		if (signal_pending(current)) {
2698 			rc = -ERESTARTSYS;
2699 			break;
2700 		}
2701 
2702 		/* get current irq counts */
2703 		spin_lock_irqsave(&info->lock,flags);
2704 		cnow = info->icount;
2705 		newsigs = info->input_signal_events;
2706 		set_current_state(TASK_INTERRUPTIBLE);
2707 		spin_unlock_irqrestore(&info->lock,flags);
2708 
2709 		/* if no change, wait aborted for some reason */
2710 		if (newsigs.dsr_up   == oldsigs.dsr_up   &&
2711 		    newsigs.dsr_down == oldsigs.dsr_down &&
2712 		    newsigs.dcd_up   == oldsigs.dcd_up   &&
2713 		    newsigs.dcd_down == oldsigs.dcd_down &&
2714 		    newsigs.cts_up   == oldsigs.cts_up   &&
2715 		    newsigs.cts_down == oldsigs.cts_down &&
2716 		    newsigs.ri_up    == oldsigs.ri_up    &&
2717 		    newsigs.ri_down  == oldsigs.ri_down  &&
2718 		    cnow.exithunt    == cprev.exithunt   &&
2719 		    cnow.rxidle      == cprev.rxidle) {
2720 			rc = -EIO;
2721 			break;
2722 		}
2723 
2724 		events = mask &
2725 			( (newsigs.dsr_up   != oldsigs.dsr_up   ? MgslEvent_DsrActive:0)   +
2726 			  (newsigs.dsr_down != oldsigs.dsr_down ? MgslEvent_DsrInactive:0) +
2727 			  (newsigs.dcd_up   != oldsigs.dcd_up   ? MgslEvent_DcdActive:0)   +
2728 			  (newsigs.dcd_down != oldsigs.dcd_down ? MgslEvent_DcdInactive:0) +
2729 			  (newsigs.cts_up   != oldsigs.cts_up   ? MgslEvent_CtsActive:0)   +
2730 			  (newsigs.cts_down != oldsigs.cts_down ? MgslEvent_CtsInactive:0) +
2731 			  (newsigs.ri_up    != oldsigs.ri_up    ? MgslEvent_RiActive:0)    +
2732 			  (newsigs.ri_down  != oldsigs.ri_down  ? MgslEvent_RiInactive:0)  +
2733 			  (cnow.exithunt    != cprev.exithunt   ? MgslEvent_ExitHuntMode:0) +
2734 			  (cnow.rxidle      != cprev.rxidle     ? MgslEvent_IdleReceived:0) );
2735 		if (events)
2736 			break;
2737 
2738 		cprev = cnow;
2739 		oldsigs = newsigs;
2740 	}
2741 
2742 	remove_wait_queue(&info->event_wait_q, &wait);
2743 	set_current_state(TASK_RUNNING);
2744 
2745 
2746 	if (mask & (MgslEvent_ExitHuntMode + MgslEvent_IdleReceived)) {
2747 		spin_lock_irqsave(&info->lock,flags);
2748 		if (!waitqueue_active(&info->event_wait_q)) {
2749 			/* disable enable exit hunt mode/idle rcvd IRQs */
2750 			wr_reg16(info, SCR,
2751 				(unsigned short)(rd_reg16(info, SCR) & ~IRQ_RXIDLE));
2752 		}
2753 		spin_unlock_irqrestore(&info->lock,flags);
2754 	}
2755 exit:
2756 	if (rc == 0)
2757 		rc = put_user(events, mask_ptr);
2758 	return rc;
2759 }
2760 
2761 static int get_interface(struct slgt_info *info, int __user *if_mode)
2762 {
2763 	DBGINFO(("%s get_interface=%x\n", info->device_name, info->if_mode));
2764 	if (put_user(info->if_mode, if_mode))
2765 		return -EFAULT;
2766 	return 0;
2767 }
2768 
2769 static int set_interface(struct slgt_info *info, int if_mode)
2770 {
2771  	unsigned long flags;
2772 	unsigned short val;
2773 
2774 	DBGINFO(("%s set_interface=%x)\n", info->device_name, if_mode));
2775 	spin_lock_irqsave(&info->lock,flags);
2776 	info->if_mode = if_mode;
2777 
2778 	msc_set_vcr(info);
2779 
2780 	/* TCR (tx control) 07  1=RTS driver control */
2781 	val = rd_reg16(info, TCR);
2782 	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
2783 		val |= BIT7;
2784 	else
2785 		val &= ~BIT7;
2786 	wr_reg16(info, TCR, val);
2787 
2788 	spin_unlock_irqrestore(&info->lock,flags);
2789 	return 0;
2790 }
2791 
2792 static int get_xsync(struct slgt_info *info, int __user *xsync)
2793 {
2794 	DBGINFO(("%s get_xsync=%x\n", info->device_name, info->xsync));
2795 	if (put_user(info->xsync, xsync))
2796 		return -EFAULT;
2797 	return 0;
2798 }
2799 
2800 /*
2801  * set extended sync pattern (1 to 4 bytes) for extended sync mode
2802  *
2803  * sync pattern is contained in least significant bytes of value
2804  * most significant byte of sync pattern is oldest (1st sent/detected)
2805  */
2806 static int set_xsync(struct slgt_info *info, int xsync)
2807 {
2808 	unsigned long flags;
2809 
2810 	DBGINFO(("%s set_xsync=%x)\n", info->device_name, xsync));
2811 	spin_lock_irqsave(&info->lock, flags);
2812 	info->xsync = xsync;
2813 	wr_reg32(info, XSR, xsync);
2814 	spin_unlock_irqrestore(&info->lock, flags);
2815 	return 0;
2816 }
2817 
2818 static int get_xctrl(struct slgt_info *info, int __user *xctrl)
2819 {
2820 	DBGINFO(("%s get_xctrl=%x\n", info->device_name, info->xctrl));
2821 	if (put_user(info->xctrl, xctrl))
2822 		return -EFAULT;
2823 	return 0;
2824 }
2825 
2826 /*
2827  * set extended control options
2828  *
2829  * xctrl[31:19] reserved, must be zero
2830  * xctrl[18:17] extended sync pattern length in bytes
2831  *              00 = 1 byte  in xsr[7:0]
2832  *              01 = 2 bytes in xsr[15:0]
2833  *              10 = 3 bytes in xsr[23:0]
2834  *              11 = 4 bytes in xsr[31:0]
2835  * xctrl[16]    1 = enable terminal count, 0=disabled
2836  * xctrl[15:0]  receive terminal count for fixed length packets
2837  *              value is count minus one (0 = 1 byte packet)
2838  *              when terminal count is reached, receiver
2839  *              automatically returns to hunt mode and receive
2840  *              FIFO contents are flushed to DMA buffers with
2841  *              end of frame (EOF) status
2842  */
2843 static int set_xctrl(struct slgt_info *info, int xctrl)
2844 {
2845 	unsigned long flags;
2846 
2847 	DBGINFO(("%s set_xctrl=%x)\n", info->device_name, xctrl));
2848 	spin_lock_irqsave(&info->lock, flags);
2849 	info->xctrl = xctrl;
2850 	wr_reg32(info, XCR, xctrl);
2851 	spin_unlock_irqrestore(&info->lock, flags);
2852 	return 0;
2853 }
2854 
2855 /*
2856  * set general purpose IO pin state and direction
2857  *
2858  * user_gpio fields:
2859  * state   each bit indicates a pin state
2860  * smask   set bit indicates pin state to set
2861  * dir     each bit indicates a pin direction (0=input, 1=output)
2862  * dmask   set bit indicates pin direction to set
2863  */
2864 static int set_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
2865 {
2866  	unsigned long flags;
2867 	struct gpio_desc gpio;
2868 	__u32 data;
2869 
2870 	if (!info->gpio_present)
2871 		return -EINVAL;
2872 	if (copy_from_user(&gpio, user_gpio, sizeof(gpio)))
2873 		return -EFAULT;
2874 	DBGINFO(("%s set_gpio state=%08x smask=%08x dir=%08x dmask=%08x\n",
2875 		 info->device_name, gpio.state, gpio.smask,
2876 		 gpio.dir, gpio.dmask));
2877 
2878 	spin_lock_irqsave(&info->port_array[0]->lock, flags);
2879 	if (gpio.dmask) {
2880 		data = rd_reg32(info, IODR);
2881 		data |= gpio.dmask & gpio.dir;
2882 		data &= ~(gpio.dmask & ~gpio.dir);
2883 		wr_reg32(info, IODR, data);
2884 	}
2885 	if (gpio.smask) {
2886 		data = rd_reg32(info, IOVR);
2887 		data |= gpio.smask & gpio.state;
2888 		data &= ~(gpio.smask & ~gpio.state);
2889 		wr_reg32(info, IOVR, data);
2890 	}
2891 	spin_unlock_irqrestore(&info->port_array[0]->lock, flags);
2892 
2893 	return 0;
2894 }
2895 
2896 /*
2897  * get general purpose IO pin state and direction
2898  */
2899 static int get_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
2900 {
2901 	struct gpio_desc gpio;
2902 	if (!info->gpio_present)
2903 		return -EINVAL;
2904 	gpio.state = rd_reg32(info, IOVR);
2905 	gpio.smask = 0xffffffff;
2906 	gpio.dir   = rd_reg32(info, IODR);
2907 	gpio.dmask = 0xffffffff;
2908 	if (copy_to_user(user_gpio, &gpio, sizeof(gpio)))
2909 		return -EFAULT;
2910 	DBGINFO(("%s get_gpio state=%08x dir=%08x\n",
2911 		 info->device_name, gpio.state, gpio.dir));
2912 	return 0;
2913 }
2914 
2915 /*
2916  * conditional wait facility
2917  */
2918 static void init_cond_wait(struct cond_wait *w, unsigned int data)
2919 {
2920 	init_waitqueue_head(&w->q);
2921 	init_waitqueue_entry(&w->wait, current);
2922 	w->data = data;
2923 }
2924 
2925 static void add_cond_wait(struct cond_wait **head, struct cond_wait *w)
2926 {
2927 	set_current_state(TASK_INTERRUPTIBLE);
2928 	add_wait_queue(&w->q, &w->wait);
2929 	w->next = *head;
2930 	*head = w;
2931 }
2932 
2933 static void remove_cond_wait(struct cond_wait **head, struct cond_wait *cw)
2934 {
2935 	struct cond_wait *w, *prev;
2936 	remove_wait_queue(&cw->q, &cw->wait);
2937 	set_current_state(TASK_RUNNING);
2938 	for (w = *head, prev = NULL ; w != NULL ; prev = w, w = w->next) {
2939 		if (w == cw) {
2940 			if (prev != NULL)
2941 				prev->next = w->next;
2942 			else
2943 				*head = w->next;
2944 			break;
2945 		}
2946 	}
2947 }
2948 
2949 static void flush_cond_wait(struct cond_wait **head)
2950 {
2951 	while (*head != NULL) {
2952 		wake_up_interruptible(&(*head)->q);
2953 		*head = (*head)->next;
2954 	}
2955 }
2956 
2957 /*
2958  * wait for general purpose I/O pin(s) to enter specified state
2959  *
2960  * user_gpio fields:
2961  * state - bit indicates target pin state
2962  * smask - set bit indicates watched pin
2963  *
2964  * The wait ends when at least one watched pin enters the specified
2965  * state. When 0 (no error) is returned, user_gpio->state is set to the
2966  * state of all GPIO pins when the wait ends.
2967  *
2968  * Note: Each pin may be a dedicated input, dedicated output, or
2969  * configurable input/output. The number and configuration of pins
2970  * varies with the specific adapter model. Only input pins (dedicated
2971  * or configured) can be monitored with this function.
2972  */
2973 static int wait_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
2974 {
2975  	unsigned long flags;
2976 	int rc = 0;
2977 	struct gpio_desc gpio;
2978 	struct cond_wait wait;
2979 	u32 state;
2980 
2981 	if (!info->gpio_present)
2982 		return -EINVAL;
2983 	if (copy_from_user(&gpio, user_gpio, sizeof(gpio)))
2984 		return -EFAULT;
2985 	DBGINFO(("%s wait_gpio() state=%08x smask=%08x\n",
2986 		 info->device_name, gpio.state, gpio.smask));
2987 	/* ignore output pins identified by set IODR bit */
2988 	if ((gpio.smask &= ~rd_reg32(info, IODR)) == 0)
2989 		return -EINVAL;
2990 	init_cond_wait(&wait, gpio.smask);
2991 
2992 	spin_lock_irqsave(&info->port_array[0]->lock, flags);
2993 	/* enable interrupts for watched pins */
2994 	wr_reg32(info, IOER, rd_reg32(info, IOER) | gpio.smask);
2995 	/* get current pin states */
2996 	state = rd_reg32(info, IOVR);
2997 
2998 	if (gpio.smask & ~(state ^ gpio.state)) {
2999 		/* already in target state */
3000 		gpio.state = state;
3001 	} else {
3002 		/* wait for target state */
3003 		add_cond_wait(&info->gpio_wait_q, &wait);
3004 		spin_unlock_irqrestore(&info->port_array[0]->lock, flags);
3005 		schedule();
3006 		if (signal_pending(current))
3007 			rc = -ERESTARTSYS;
3008 		else
3009 			gpio.state = wait.data;
3010 		spin_lock_irqsave(&info->port_array[0]->lock, flags);
3011 		remove_cond_wait(&info->gpio_wait_q, &wait);
3012 	}
3013 
3014 	/* disable all GPIO interrupts if no waiting processes */
3015 	if (info->gpio_wait_q == NULL)
3016 		wr_reg32(info, IOER, 0);
3017 	spin_unlock_irqrestore(&info->port_array[0]->lock, flags);
3018 
3019 	if ((rc == 0) && copy_to_user(user_gpio, &gpio, sizeof(gpio)))
3020 		rc = -EFAULT;
3021 	return rc;
3022 }
3023 
3024 static int modem_input_wait(struct slgt_info *info,int arg)
3025 {
3026  	unsigned long flags;
3027 	int rc;
3028 	struct mgsl_icount cprev, cnow;
3029 	DECLARE_WAITQUEUE(wait, current);
3030 
3031 	/* save current irq counts */
3032 	spin_lock_irqsave(&info->lock,flags);
3033 	cprev = info->icount;
3034 	add_wait_queue(&info->status_event_wait_q, &wait);
3035 	set_current_state(TASK_INTERRUPTIBLE);
3036 	spin_unlock_irqrestore(&info->lock,flags);
3037 
3038 	for(;;) {
3039 		schedule();
3040 		if (signal_pending(current)) {
3041 			rc = -ERESTARTSYS;
3042 			break;
3043 		}
3044 
3045 		/* get new irq counts */
3046 		spin_lock_irqsave(&info->lock,flags);
3047 		cnow = info->icount;
3048 		set_current_state(TASK_INTERRUPTIBLE);
3049 		spin_unlock_irqrestore(&info->lock,flags);
3050 
3051 		/* if no change, wait aborted for some reason */
3052 		if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
3053 		    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
3054 			rc = -EIO;
3055 			break;
3056 		}
3057 
3058 		/* check for change in caller specified modem input */
3059 		if ((arg & TIOCM_RNG && cnow.rng != cprev.rng) ||
3060 		    (arg & TIOCM_DSR && cnow.dsr != cprev.dsr) ||
3061 		    (arg & TIOCM_CD  && cnow.dcd != cprev.dcd) ||
3062 		    (arg & TIOCM_CTS && cnow.cts != cprev.cts)) {
3063 			rc = 0;
3064 			break;
3065 		}
3066 
3067 		cprev = cnow;
3068 	}
3069 	remove_wait_queue(&info->status_event_wait_q, &wait);
3070 	set_current_state(TASK_RUNNING);
3071 	return rc;
3072 }
3073 
3074 /*
3075  *  return state of serial control and status signals
3076  */
3077 static int tiocmget(struct tty_struct *tty)
3078 {
3079 	struct slgt_info *info = tty->driver_data;
3080 	unsigned int result;
3081  	unsigned long flags;
3082 
3083 	spin_lock_irqsave(&info->lock,flags);
3084  	get_gtsignals(info);
3085 	spin_unlock_irqrestore(&info->lock,flags);
3086 
3087 	result = ((info->signals & SerialSignal_RTS) ? TIOCM_RTS:0) +
3088 		((info->signals & SerialSignal_DTR) ? TIOCM_DTR:0) +
3089 		((info->signals & SerialSignal_DCD) ? TIOCM_CAR:0) +
3090 		((info->signals & SerialSignal_RI)  ? TIOCM_RNG:0) +
3091 		((info->signals & SerialSignal_DSR) ? TIOCM_DSR:0) +
3092 		((info->signals & SerialSignal_CTS) ? TIOCM_CTS:0);
3093 
3094 	DBGINFO(("%s tiocmget value=%08X\n", info->device_name, result));
3095 	return result;
3096 }
3097 
3098 /*
3099  * set modem control signals (DTR/RTS)
3100  *
3101  * 	cmd	signal command: TIOCMBIS = set bit TIOCMBIC = clear bit
3102  *		TIOCMSET = set/clear signal values
3103  * 	value	bit mask for command
3104  */
3105 static int tiocmset(struct tty_struct *tty,
3106 		    unsigned int set, unsigned int clear)
3107 {
3108 	struct slgt_info *info = tty->driver_data;
3109  	unsigned long flags;
3110 
3111 	DBGINFO(("%s tiocmset(%x,%x)\n", info->device_name, set, clear));
3112 
3113 	if (set & TIOCM_RTS)
3114 		info->signals |= SerialSignal_RTS;
3115 	if (set & TIOCM_DTR)
3116 		info->signals |= SerialSignal_DTR;
3117 	if (clear & TIOCM_RTS)
3118 		info->signals &= ~SerialSignal_RTS;
3119 	if (clear & TIOCM_DTR)
3120 		info->signals &= ~SerialSignal_DTR;
3121 
3122 	spin_lock_irqsave(&info->lock,flags);
3123 	set_gtsignals(info);
3124 	spin_unlock_irqrestore(&info->lock,flags);
3125 	return 0;
3126 }
3127 
3128 static bool carrier_raised(struct tty_port *port)
3129 {
3130 	unsigned long flags;
3131 	struct slgt_info *info = container_of(port, struct slgt_info, port);
3132 
3133 	spin_lock_irqsave(&info->lock,flags);
3134 	get_gtsignals(info);
3135 	spin_unlock_irqrestore(&info->lock,flags);
3136 
3137 	return info->signals & SerialSignal_DCD;
3138 }
3139 
3140 static void dtr_rts(struct tty_port *port, bool active)
3141 {
3142 	unsigned long flags;
3143 	struct slgt_info *info = container_of(port, struct slgt_info, port);
3144 
3145 	spin_lock_irqsave(&info->lock,flags);
3146 	if (active)
3147 		info->signals |= SerialSignal_RTS | SerialSignal_DTR;
3148 	else
3149 		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
3150 	set_gtsignals(info);
3151 	spin_unlock_irqrestore(&info->lock,flags);
3152 }
3153 
3154 
3155 /*
3156  *  block current process until the device is ready to open
3157  */
3158 static int block_til_ready(struct tty_struct *tty, struct file *filp,
3159 			   struct slgt_info *info)
3160 {
3161 	DECLARE_WAITQUEUE(wait, current);
3162 	int		retval;
3163 	bool		do_clocal = false;
3164 	unsigned long	flags;
3165 	bool		cd;
3166 	struct tty_port *port = &info->port;
3167 
3168 	DBGINFO(("%s block_til_ready\n", tty->driver->name));
3169 
3170 	if (filp->f_flags & O_NONBLOCK || tty_io_error(tty)) {
3171 		/* nonblock mode is set or port is not enabled */
3172 		tty_port_set_active(port, true);
3173 		return 0;
3174 	}
3175 
3176 	if (C_CLOCAL(tty))
3177 		do_clocal = true;
3178 
3179 	/* Wait for carrier detect and the line to become
3180 	 * free (i.e., not in use by the callout).  While we are in
3181 	 * this loop, port->count is dropped by one, so that
3182 	 * close() knows when to free things.  We restore it upon
3183 	 * exit, either normal or abnormal.
3184 	 */
3185 
3186 	retval = 0;
3187 	add_wait_queue(&port->open_wait, &wait);
3188 
3189 	spin_lock_irqsave(&info->lock, flags);
3190 	port->count--;
3191 	spin_unlock_irqrestore(&info->lock, flags);
3192 	port->blocked_open++;
3193 
3194 	while (1) {
3195 		if (C_BAUD(tty) && tty_port_initialized(port))
3196 			tty_port_raise_dtr_rts(port);
3197 
3198 		set_current_state(TASK_INTERRUPTIBLE);
3199 
3200 		if (tty_hung_up_p(filp) || !tty_port_initialized(port)) {
3201 			retval = (port->flags & ASYNC_HUP_NOTIFY) ?
3202 					-EAGAIN : -ERESTARTSYS;
3203 			break;
3204 		}
3205 
3206 		cd = tty_port_carrier_raised(port);
3207 		if (do_clocal || cd)
3208 			break;
3209 
3210 		if (signal_pending(current)) {
3211 			retval = -ERESTARTSYS;
3212 			break;
3213 		}
3214 
3215 		DBGINFO(("%s block_til_ready wait\n", tty->driver->name));
3216 		tty_unlock(tty);
3217 		schedule();
3218 		tty_lock(tty);
3219 	}
3220 
3221 	set_current_state(TASK_RUNNING);
3222 	remove_wait_queue(&port->open_wait, &wait);
3223 
3224 	if (!tty_hung_up_p(filp))
3225 		port->count++;
3226 	port->blocked_open--;
3227 
3228 	if (!retval)
3229 		tty_port_set_active(port, true);
3230 
3231 	DBGINFO(("%s block_til_ready ready, rc=%d\n", tty->driver->name, retval));
3232 	return retval;
3233 }
3234 
3235 /*
3236  * allocate buffers used for calling line discipline receive_buf
3237  * directly in synchronous mode
3238  * note: add 5 bytes to max frame size to allow appending
3239  * 32-bit CRC and status byte when configured to do so
3240  */
3241 static int alloc_tmp_rbuf(struct slgt_info *info)
3242 {
3243 	info->tmp_rbuf = kmalloc(info->max_frame_size + 5, GFP_KERNEL);
3244 	if (info->tmp_rbuf == NULL)
3245 		return -ENOMEM;
3246 
3247 	return 0;
3248 }
3249 
3250 static void free_tmp_rbuf(struct slgt_info *info)
3251 {
3252 	kfree(info->tmp_rbuf);
3253 	info->tmp_rbuf = NULL;
3254 }
3255 
3256 /*
3257  * allocate DMA descriptor lists.
3258  */
3259 static int alloc_desc(struct slgt_info *info)
3260 {
3261 	unsigned int i;
3262 	unsigned int pbufs;
3263 
3264 	/* allocate memory to hold descriptor lists */
3265 	info->bufs = dma_alloc_coherent(&info->pdev->dev, DESC_LIST_SIZE,
3266 					&info->bufs_dma_addr, GFP_KERNEL);
3267 	if (info->bufs == NULL)
3268 		return -ENOMEM;
3269 
3270 	info->rbufs = (struct slgt_desc*)info->bufs;
3271 	info->tbufs = ((struct slgt_desc*)info->bufs) + info->rbuf_count;
3272 
3273 	pbufs = (unsigned int)info->bufs_dma_addr;
3274 
3275 	/*
3276 	 * Build circular lists of descriptors
3277 	 */
3278 
3279 	for (i=0; i < info->rbuf_count; i++) {
3280 		/* physical address of this descriptor */
3281 		info->rbufs[i].pdesc = pbufs + (i * sizeof(struct slgt_desc));
3282 
3283 		/* physical address of next descriptor */
3284 		if (i == info->rbuf_count - 1)
3285 			info->rbufs[i].next = cpu_to_le32(pbufs);
3286 		else
3287 			info->rbufs[i].next = cpu_to_le32(pbufs + ((i+1) * sizeof(struct slgt_desc)));
3288 		set_desc_count(info->rbufs[i], DMABUFSIZE);
3289 	}
3290 
3291 	for (i=0; i < info->tbuf_count; i++) {
3292 		/* physical address of this descriptor */
3293 		info->tbufs[i].pdesc = pbufs + ((info->rbuf_count + i) * sizeof(struct slgt_desc));
3294 
3295 		/* physical address of next descriptor */
3296 		if (i == info->tbuf_count - 1)
3297 			info->tbufs[i].next = cpu_to_le32(pbufs + info->rbuf_count * sizeof(struct slgt_desc));
3298 		else
3299 			info->tbufs[i].next = cpu_to_le32(pbufs + ((info->rbuf_count + i + 1) * sizeof(struct slgt_desc)));
3300 	}
3301 
3302 	return 0;
3303 }
3304 
3305 static void free_desc(struct slgt_info *info)
3306 {
3307 	if (info->bufs != NULL) {
3308 		dma_free_coherent(&info->pdev->dev, DESC_LIST_SIZE,
3309 				  info->bufs, info->bufs_dma_addr);
3310 		info->bufs  = NULL;
3311 		info->rbufs = NULL;
3312 		info->tbufs = NULL;
3313 	}
3314 }
3315 
3316 static int alloc_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count)
3317 {
3318 	int i;
3319 	for (i=0; i < count; i++) {
3320 		bufs[i].buf = dma_alloc_coherent(&info->pdev->dev, DMABUFSIZE,
3321 						 &bufs[i].buf_dma_addr, GFP_KERNEL);
3322 		if (!bufs[i].buf)
3323 			return -ENOMEM;
3324 		bufs[i].pbuf  = cpu_to_le32((unsigned int)bufs[i].buf_dma_addr);
3325 	}
3326 	return 0;
3327 }
3328 
3329 static void free_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count)
3330 {
3331 	int i;
3332 	for (i=0; i < count; i++) {
3333 		if (bufs[i].buf == NULL)
3334 			continue;
3335 		dma_free_coherent(&info->pdev->dev, DMABUFSIZE, bufs[i].buf,
3336 				  bufs[i].buf_dma_addr);
3337 		bufs[i].buf = NULL;
3338 	}
3339 }
3340 
3341 static int alloc_dma_bufs(struct slgt_info *info)
3342 {
3343 	info->rbuf_count = 32;
3344 	info->tbuf_count = 32;
3345 
3346 	if (alloc_desc(info) < 0 ||
3347 	    alloc_bufs(info, info->rbufs, info->rbuf_count) < 0 ||
3348 	    alloc_bufs(info, info->tbufs, info->tbuf_count) < 0 ||
3349 	    alloc_tmp_rbuf(info) < 0) {
3350 		DBGERR(("%s DMA buffer alloc fail\n", info->device_name));
3351 		return -ENOMEM;
3352 	}
3353 	reset_rbufs(info);
3354 	return 0;
3355 }
3356 
3357 static void free_dma_bufs(struct slgt_info *info)
3358 {
3359 	if (info->bufs) {
3360 		free_bufs(info, info->rbufs, info->rbuf_count);
3361 		free_bufs(info, info->tbufs, info->tbuf_count);
3362 		free_desc(info);
3363 	}
3364 	free_tmp_rbuf(info);
3365 }
3366 
3367 static int claim_resources(struct slgt_info *info)
3368 {
3369 	if (request_mem_region(info->phys_reg_addr, SLGT_REG_SIZE, "synclink_gt") == NULL) {
3370 		DBGERR(("%s reg addr conflict, addr=%08X\n",
3371 			info->device_name, info->phys_reg_addr));
3372 		info->init_error = DiagStatus_AddressConflict;
3373 		goto errout;
3374 	}
3375 	else
3376 		info->reg_addr_requested = true;
3377 
3378 	info->reg_addr = ioremap(info->phys_reg_addr, SLGT_REG_SIZE);
3379 	if (!info->reg_addr) {
3380 		DBGERR(("%s can't map device registers, addr=%08X\n",
3381 			info->device_name, info->phys_reg_addr));
3382 		info->init_error = DiagStatus_CantAssignPciResources;
3383 		goto errout;
3384 	}
3385 	return 0;
3386 
3387 errout:
3388 	release_resources(info);
3389 	return -ENODEV;
3390 }
3391 
3392 static void release_resources(struct slgt_info *info)
3393 {
3394 	if (info->irq_requested) {
3395 		free_irq(info->irq_level, info);
3396 		info->irq_requested = false;
3397 	}
3398 
3399 	if (info->reg_addr_requested) {
3400 		release_mem_region(info->phys_reg_addr, SLGT_REG_SIZE);
3401 		info->reg_addr_requested = false;
3402 	}
3403 
3404 	if (info->reg_addr) {
3405 		iounmap(info->reg_addr);
3406 		info->reg_addr = NULL;
3407 	}
3408 }
3409 
3410 /* Add the specified device instance data structure to the
3411  * global linked list of devices and increment the device count.
3412  */
3413 static void add_device(struct slgt_info *info)
3414 {
3415 	char *devstr;
3416 
3417 	info->next_device = NULL;
3418 	info->line = slgt_device_count;
3419 	sprintf(info->device_name, "%s%d", tty_dev_prefix, info->line);
3420 
3421 	if (info->line < MAX_DEVICES) {
3422 		if (maxframe[info->line])
3423 			info->max_frame_size = maxframe[info->line];
3424 	}
3425 
3426 	slgt_device_count++;
3427 
3428 	if (!slgt_device_list)
3429 		slgt_device_list = info;
3430 	else {
3431 		struct slgt_info *current_dev = slgt_device_list;
3432 		while(current_dev->next_device)
3433 			current_dev = current_dev->next_device;
3434 		current_dev->next_device = info;
3435 	}
3436 
3437 	if (info->max_frame_size < 4096)
3438 		info->max_frame_size = 4096;
3439 	else if (info->max_frame_size > 65535)
3440 		info->max_frame_size = 65535;
3441 
3442 	switch(info->pdev->device) {
3443 	case SYNCLINK_GT_DEVICE_ID:
3444 		devstr = "GT";
3445 		break;
3446 	case SYNCLINK_GT2_DEVICE_ID:
3447 		devstr = "GT2";
3448 		break;
3449 	case SYNCLINK_GT4_DEVICE_ID:
3450 		devstr = "GT4";
3451 		break;
3452 	case SYNCLINK_AC_DEVICE_ID:
3453 		devstr = "AC";
3454 		info->params.mode = MGSL_MODE_ASYNC;
3455 		break;
3456 	default:
3457 		devstr = "(unknown model)";
3458 	}
3459 	printk("SyncLink %s %s IO=%08x IRQ=%d MaxFrameSize=%u\n",
3460 		devstr, info->device_name, info->phys_reg_addr,
3461 		info->irq_level, info->max_frame_size);
3462 
3463 #if SYNCLINK_GENERIC_HDLC
3464 	hdlcdev_init(info);
3465 #endif
3466 }
3467 
3468 static const struct tty_port_operations slgt_port_ops = {
3469 	.carrier_raised = carrier_raised,
3470 	.dtr_rts = dtr_rts,
3471 };
3472 
3473 /*
3474  *  allocate device instance structure, return NULL on failure
3475  */
3476 static struct slgt_info *alloc_dev(int adapter_num, int port_num, struct pci_dev *pdev)
3477 {
3478 	struct slgt_info *info;
3479 
3480 	info = kzalloc(sizeof(struct slgt_info), GFP_KERNEL);
3481 
3482 	if (!info) {
3483 		DBGERR(("%s device alloc failed adapter=%d port=%d\n",
3484 			driver_name, adapter_num, port_num));
3485 	} else {
3486 		tty_port_init(&info->port);
3487 		info->port.ops = &slgt_port_ops;
3488 		INIT_WORK(&info->task, bh_handler);
3489 		info->max_frame_size = 4096;
3490 		info->base_clock = 14745600;
3491 		info->rbuf_fill_level = DMABUFSIZE;
3492 		init_waitqueue_head(&info->status_event_wait_q);
3493 		init_waitqueue_head(&info->event_wait_q);
3494 		spin_lock_init(&info->netlock);
3495 		memcpy(&info->params,&default_params,sizeof(MGSL_PARAMS));
3496 		info->idle_mode = HDLC_TXIDLE_FLAGS;
3497 		info->adapter_num = adapter_num;
3498 		info->port_num = port_num;
3499 
3500 		timer_setup(&info->tx_timer, tx_timeout, 0);
3501 		timer_setup(&info->rx_timer, rx_timeout, 0);
3502 
3503 		/* Copy configuration info to device instance data */
3504 		info->pdev = pdev;
3505 		info->irq_level = pdev->irq;
3506 		info->phys_reg_addr = pci_resource_start(pdev,0);
3507 
3508 		info->bus_type = MGSL_BUS_TYPE_PCI;
3509 		info->irq_flags = IRQF_SHARED;
3510 
3511 		info->init_error = -1; /* assume error, set to 0 on successful init */
3512 	}
3513 
3514 	return info;
3515 }
3516 
3517 static void device_init(int adapter_num, struct pci_dev *pdev)
3518 {
3519 	struct slgt_info *port_array[SLGT_MAX_PORTS];
3520 	int i;
3521 	int port_count = 1;
3522 
3523 	if (pdev->device == SYNCLINK_GT2_DEVICE_ID)
3524 		port_count = 2;
3525 	else if (pdev->device == SYNCLINK_GT4_DEVICE_ID)
3526 		port_count = 4;
3527 
3528 	/* allocate device instances for all ports */
3529 	for (i=0; i < port_count; ++i) {
3530 		port_array[i] = alloc_dev(adapter_num, i, pdev);
3531 		if (port_array[i] == NULL) {
3532 			for (--i; i >= 0; --i) {
3533 				tty_port_destroy(&port_array[i]->port);
3534 				kfree(port_array[i]);
3535 			}
3536 			return;
3537 		}
3538 	}
3539 
3540 	/* give copy of port_array to all ports and add to device list  */
3541 	for (i=0; i < port_count; ++i) {
3542 		memcpy(port_array[i]->port_array, port_array, sizeof(port_array));
3543 		add_device(port_array[i]);
3544 		port_array[i]->port_count = port_count;
3545 		spin_lock_init(&port_array[i]->lock);
3546 	}
3547 
3548 	/* Allocate and claim adapter resources */
3549 	if (!claim_resources(port_array[0])) {
3550 
3551 		alloc_dma_bufs(port_array[0]);
3552 
3553 		/* copy resource information from first port to others */
3554 		for (i = 1; i < port_count; ++i) {
3555 			port_array[i]->irq_level = port_array[0]->irq_level;
3556 			port_array[i]->reg_addr  = port_array[0]->reg_addr;
3557 			alloc_dma_bufs(port_array[i]);
3558 		}
3559 
3560 		if (request_irq(port_array[0]->irq_level,
3561 					slgt_interrupt,
3562 					port_array[0]->irq_flags,
3563 					port_array[0]->device_name,
3564 					port_array[0]) < 0) {
3565 			DBGERR(("%s request_irq failed IRQ=%d\n",
3566 				port_array[0]->device_name,
3567 				port_array[0]->irq_level));
3568 		} else {
3569 			port_array[0]->irq_requested = true;
3570 			adapter_test(port_array[0]);
3571 			for (i=1 ; i < port_count ; i++) {
3572 				port_array[i]->init_error = port_array[0]->init_error;
3573 				port_array[i]->gpio_present = port_array[0]->gpio_present;
3574 			}
3575 		}
3576 	}
3577 
3578 	for (i = 0; i < port_count; ++i) {
3579 		struct slgt_info *info = port_array[i];
3580 		tty_port_register_device(&info->port, serial_driver, info->line,
3581 				&info->pdev->dev);
3582 	}
3583 }
3584 
3585 static int init_one(struct pci_dev *dev,
3586 			      const struct pci_device_id *ent)
3587 {
3588 	if (pci_enable_device(dev)) {
3589 		printk("error enabling pci device %p\n", dev);
3590 		return -EIO;
3591 	}
3592 	pci_set_master(dev);
3593 	device_init(slgt_device_count, dev);
3594 	return 0;
3595 }
3596 
3597 static void remove_one(struct pci_dev *dev)
3598 {
3599 }
3600 
3601 static const struct tty_operations ops = {
3602 	.open = open,
3603 	.close = close,
3604 	.write = write,
3605 	.put_char = put_char,
3606 	.flush_chars = flush_chars,
3607 	.write_room = write_room,
3608 	.chars_in_buffer = chars_in_buffer,
3609 	.flush_buffer = flush_buffer,
3610 	.ioctl = ioctl,
3611 	.compat_ioctl = slgt_compat_ioctl,
3612 	.throttle = throttle,
3613 	.unthrottle = unthrottle,
3614 	.send_xchar = send_xchar,
3615 	.break_ctl = set_break,
3616 	.wait_until_sent = wait_until_sent,
3617 	.set_termios = set_termios,
3618 	.stop = tx_hold,
3619 	.start = tx_release,
3620 	.hangup = hangup,
3621 	.tiocmget = tiocmget,
3622 	.tiocmset = tiocmset,
3623 	.get_icount = get_icount,
3624 	.proc_show = synclink_gt_proc_show,
3625 };
3626 
3627 static void slgt_cleanup(void)
3628 {
3629 	struct slgt_info *info;
3630 	struct slgt_info *tmp;
3631 
3632 	printk(KERN_INFO "unload %s\n", driver_name);
3633 
3634 	if (serial_driver) {
3635 		for (info=slgt_device_list ; info != NULL ; info=info->next_device)
3636 			tty_unregister_device(serial_driver, info->line);
3637 		tty_unregister_driver(serial_driver);
3638 		tty_driver_kref_put(serial_driver);
3639 	}
3640 
3641 	/* reset devices */
3642 	info = slgt_device_list;
3643 	while(info) {
3644 		reset_port(info);
3645 		info = info->next_device;
3646 	}
3647 
3648 	/* release devices */
3649 	info = slgt_device_list;
3650 	while(info) {
3651 #if SYNCLINK_GENERIC_HDLC
3652 		hdlcdev_exit(info);
3653 #endif
3654 		free_dma_bufs(info);
3655 		free_tmp_rbuf(info);
3656 		if (info->port_num == 0)
3657 			release_resources(info);
3658 		tmp = info;
3659 		info = info->next_device;
3660 		tty_port_destroy(&tmp->port);
3661 		kfree(tmp);
3662 	}
3663 
3664 	if (pci_registered)
3665 		pci_unregister_driver(&pci_driver);
3666 }
3667 
3668 /*
3669  *  Driver initialization entry point.
3670  */
3671 static int __init slgt_init(void)
3672 {
3673 	int rc;
3674 
3675 	printk(KERN_INFO "%s\n", driver_name);
3676 
3677 	serial_driver = tty_alloc_driver(MAX_DEVICES, TTY_DRIVER_REAL_RAW |
3678 			TTY_DRIVER_DYNAMIC_DEV);
3679 	if (IS_ERR(serial_driver)) {
3680 		printk("%s can't allocate tty driver\n", driver_name);
3681 		return PTR_ERR(serial_driver);
3682 	}
3683 
3684 	/* Initialize the tty_driver structure */
3685 
3686 	serial_driver->driver_name = slgt_driver_name;
3687 	serial_driver->name = tty_dev_prefix;
3688 	serial_driver->major = ttymajor;
3689 	serial_driver->minor_start = 64;
3690 	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
3691 	serial_driver->subtype = SERIAL_TYPE_NORMAL;
3692 	serial_driver->init_termios = tty_std_termios;
3693 	serial_driver->init_termios.c_cflag =
3694 		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
3695 	serial_driver->init_termios.c_ispeed = 9600;
3696 	serial_driver->init_termios.c_ospeed = 9600;
3697 	tty_set_operations(serial_driver, &ops);
3698 	if ((rc = tty_register_driver(serial_driver)) < 0) {
3699 		DBGERR(("%s can't register serial driver\n", driver_name));
3700 		tty_driver_kref_put(serial_driver);
3701 		serial_driver = NULL;
3702 		goto error;
3703 	}
3704 
3705 	printk(KERN_INFO "%s, tty major#%d\n",
3706 	       driver_name, serial_driver->major);
3707 
3708 	slgt_device_count = 0;
3709 	if ((rc = pci_register_driver(&pci_driver)) < 0) {
3710 		printk("%s pci_register_driver error=%d\n", driver_name, rc);
3711 		goto error;
3712 	}
3713 	pci_registered = true;
3714 
3715 	if (!slgt_device_list)
3716 		printk("%s no devices found\n",driver_name);
3717 
3718 	return 0;
3719 
3720 error:
3721 	slgt_cleanup();
3722 	return rc;
3723 }
3724 
3725 static void __exit slgt_exit(void)
3726 {
3727 	slgt_cleanup();
3728 }
3729 
3730 module_init(slgt_init);
3731 module_exit(slgt_exit);
3732 
3733 /*
3734  * register access routines
3735  */
3736 
3737 #define CALC_REGADDR() \
3738 	unsigned long reg_addr = ((unsigned long)info->reg_addr) + addr; \
3739 	if (addr >= 0x80) \
3740 		reg_addr += (info->port_num) * 32; \
3741 	else if (addr >= 0x40)	\
3742 		reg_addr += (info->port_num) * 16;
3743 
3744 static __u8 rd_reg8(struct slgt_info *info, unsigned int addr)
3745 {
3746 	CALC_REGADDR();
3747 	return readb((void __iomem *)reg_addr);
3748 }
3749 
3750 static void wr_reg8(struct slgt_info *info, unsigned int addr, __u8 value)
3751 {
3752 	CALC_REGADDR();
3753 	writeb(value, (void __iomem *)reg_addr);
3754 }
3755 
3756 static __u16 rd_reg16(struct slgt_info *info, unsigned int addr)
3757 {
3758 	CALC_REGADDR();
3759 	return readw((void __iomem *)reg_addr);
3760 }
3761 
3762 static void wr_reg16(struct slgt_info *info, unsigned int addr, __u16 value)
3763 {
3764 	CALC_REGADDR();
3765 	writew(value, (void __iomem *)reg_addr);
3766 }
3767 
3768 static __u32 rd_reg32(struct slgt_info *info, unsigned int addr)
3769 {
3770 	CALC_REGADDR();
3771 	return readl((void __iomem *)reg_addr);
3772 }
3773 
3774 static void wr_reg32(struct slgt_info *info, unsigned int addr, __u32 value)
3775 {
3776 	CALC_REGADDR();
3777 	writel(value, (void __iomem *)reg_addr);
3778 }
3779 
3780 static void rdma_reset(struct slgt_info *info)
3781 {
3782 	unsigned int i;
3783 
3784 	/* set reset bit */
3785 	wr_reg32(info, RDCSR, BIT1);
3786 
3787 	/* wait for enable bit cleared */
3788 	for(i=0 ; i < 1000 ; i++)
3789 		if (!(rd_reg32(info, RDCSR) & BIT0))
3790 			break;
3791 }
3792 
3793 static void tdma_reset(struct slgt_info *info)
3794 {
3795 	unsigned int i;
3796 
3797 	/* set reset bit */
3798 	wr_reg32(info, TDCSR, BIT1);
3799 
3800 	/* wait for enable bit cleared */
3801 	for(i=0 ; i < 1000 ; i++)
3802 		if (!(rd_reg32(info, TDCSR) & BIT0))
3803 			break;
3804 }
3805 
3806 /*
3807  * enable internal loopback
3808  * TxCLK and RxCLK are generated from BRG
3809  * and TxD is looped back to RxD internally.
3810  */
3811 static void enable_loopback(struct slgt_info *info)
3812 {
3813 	/* SCR (serial control) BIT2=loopback enable */
3814 	wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) | BIT2));
3815 
3816 	if (info->params.mode != MGSL_MODE_ASYNC) {
3817 		/* CCR (clock control)
3818 		 * 07..05  tx clock source (010 = BRG)
3819 		 * 04..02  rx clock source (010 = BRG)
3820 		 * 01      auxclk enable   (0 = disable)
3821 		 * 00      BRG enable      (1 = enable)
3822 		 *
3823 		 * 0100 1001
3824 		 */
3825 		wr_reg8(info, CCR, 0x49);
3826 
3827 		/* set speed if available, otherwise use default */
3828 		if (info->params.clock_speed)
3829 			set_rate(info, info->params.clock_speed);
3830 		else
3831 			set_rate(info, 3686400);
3832 	}
3833 }
3834 
3835 /*
3836  *  set baud rate generator to specified rate
3837  */
3838 static void set_rate(struct slgt_info *info, u32 rate)
3839 {
3840 	unsigned int div;
3841 	unsigned int osc = info->base_clock;
3842 
3843 	/* div = osc/rate - 1
3844 	 *
3845 	 * Round div up if osc/rate is not integer to
3846 	 * force to next slowest rate.
3847 	 */
3848 
3849 	if (rate) {
3850 		div = osc/rate;
3851 		if (!(osc % rate) && div)
3852 			div--;
3853 		wr_reg16(info, BDR, (unsigned short)div);
3854 	}
3855 }
3856 
3857 static void rx_stop(struct slgt_info *info)
3858 {
3859 	unsigned short val;
3860 
3861 	/* disable and reset receiver */
3862 	val = rd_reg16(info, RCR) & ~BIT1;          /* clear enable bit */
3863 	wr_reg16(info, RCR, (unsigned short)(val | BIT2)); /* set reset bit */
3864 	wr_reg16(info, RCR, val);                  /* clear reset bit */
3865 
3866 	slgt_irq_off(info, IRQ_RXOVER + IRQ_RXDATA + IRQ_RXIDLE);
3867 
3868 	/* clear pending rx interrupts */
3869 	wr_reg16(info, SSR, IRQ_RXIDLE + IRQ_RXOVER);
3870 
3871 	rdma_reset(info);
3872 
3873 	info->rx_enabled = false;
3874 	info->rx_restart = false;
3875 }
3876 
3877 static void rx_start(struct slgt_info *info)
3878 {
3879 	unsigned short val;
3880 
3881 	slgt_irq_off(info, IRQ_RXOVER + IRQ_RXDATA);
3882 
3883 	/* clear pending rx overrun IRQ */
3884 	wr_reg16(info, SSR, IRQ_RXOVER);
3885 
3886 	/* reset and disable receiver */
3887 	val = rd_reg16(info, RCR) & ~BIT1; /* clear enable bit */
3888 	wr_reg16(info, RCR, (unsigned short)(val | BIT2)); /* set reset bit */
3889 	wr_reg16(info, RCR, val);                  /* clear reset bit */
3890 
3891 	rdma_reset(info);
3892 	reset_rbufs(info);
3893 
3894 	if (info->rx_pio) {
3895 		/* rx request when rx FIFO not empty */
3896 		wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) & ~BIT14));
3897 		slgt_irq_on(info, IRQ_RXDATA);
3898 		if (info->params.mode == MGSL_MODE_ASYNC) {
3899 			/* enable saving of rx status */
3900 			wr_reg32(info, RDCSR, BIT6);
3901 		}
3902 	} else {
3903 		/* rx request when rx FIFO half full */
3904 		wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) | BIT14));
3905 		/* set 1st descriptor address */
3906 		wr_reg32(info, RDDAR, info->rbufs[0].pdesc);
3907 
3908 		if (info->params.mode != MGSL_MODE_ASYNC) {
3909 			/* enable rx DMA and DMA interrupt */
3910 			wr_reg32(info, RDCSR, (BIT2 + BIT0));
3911 		} else {
3912 			/* enable saving of rx status, rx DMA and DMA interrupt */
3913 			wr_reg32(info, RDCSR, (BIT6 + BIT2 + BIT0));
3914 		}
3915 	}
3916 
3917 	slgt_irq_on(info, IRQ_RXOVER);
3918 
3919 	/* enable receiver */
3920 	wr_reg16(info, RCR, (unsigned short)(rd_reg16(info, RCR) | BIT1));
3921 
3922 	info->rx_restart = false;
3923 	info->rx_enabled = true;
3924 }
3925 
3926 static void tx_start(struct slgt_info *info)
3927 {
3928 	if (!info->tx_enabled) {
3929 		wr_reg16(info, TCR,
3930 			 (unsigned short)((rd_reg16(info, TCR) | BIT1) & ~BIT2));
3931 		info->tx_enabled = true;
3932 	}
3933 
3934 	if (desc_count(info->tbufs[info->tbuf_start])) {
3935 		info->drop_rts_on_tx_done = false;
3936 
3937 		if (info->params.mode != MGSL_MODE_ASYNC) {
3938 			if (info->params.flags & HDLC_FLAG_AUTO_RTS) {
3939 				get_gtsignals(info);
3940 				if (!(info->signals & SerialSignal_RTS)) {
3941 					info->signals |= SerialSignal_RTS;
3942 					set_gtsignals(info);
3943 					info->drop_rts_on_tx_done = true;
3944 				}
3945 			}
3946 
3947 			slgt_irq_off(info, IRQ_TXDATA);
3948 			slgt_irq_on(info, IRQ_TXUNDER + IRQ_TXIDLE);
3949 			/* clear tx idle and underrun status bits */
3950 			wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER));
3951 		} else {
3952 			slgt_irq_off(info, IRQ_TXDATA);
3953 			slgt_irq_on(info, IRQ_TXIDLE);
3954 			/* clear tx idle status bit */
3955 			wr_reg16(info, SSR, IRQ_TXIDLE);
3956 		}
3957 		/* set 1st descriptor address and start DMA */
3958 		wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc);
3959 		wr_reg32(info, TDCSR, BIT2 + BIT0);
3960 		info->tx_active = true;
3961 	}
3962 }
3963 
3964 static void tx_stop(struct slgt_info *info)
3965 {
3966 	unsigned short val;
3967 
3968 	del_timer(&info->tx_timer);
3969 
3970 	tdma_reset(info);
3971 
3972 	/* reset and disable transmitter */
3973 	val = rd_reg16(info, TCR) & ~BIT1;          /* clear enable bit */
3974 	wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
3975 
3976 	slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);
3977 
3978 	/* clear tx idle and underrun status bit */
3979 	wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER));
3980 
3981 	reset_tbufs(info);
3982 
3983 	info->tx_enabled = false;
3984 	info->tx_active = false;
3985 }
3986 
3987 static void reset_port(struct slgt_info *info)
3988 {
3989 	if (!info->reg_addr)
3990 		return;
3991 
3992 	tx_stop(info);
3993 	rx_stop(info);
3994 
3995 	info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
3996 	set_gtsignals(info);
3997 
3998 	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
3999 }
4000 
4001 static void reset_adapter(struct slgt_info *info)
4002 {
4003 	int i;
4004 	for (i=0; i < info->port_count; ++i) {
4005 		if (info->port_array[i])
4006 			reset_port(info->port_array[i]);
4007 	}
4008 }
4009 
4010 static void async_mode(struct slgt_info *info)
4011 {
4012   	unsigned short val;
4013 
4014 	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
4015 	tx_stop(info);
4016 	rx_stop(info);
4017 
4018 	/* TCR (tx control)
4019 	 *
4020 	 * 15..13  mode, 010=async
4021 	 * 12..10  encoding, 000=NRZ
4022 	 * 09      parity enable
4023 	 * 08      1=odd parity, 0=even parity
4024 	 * 07      1=RTS driver control
4025 	 * 06      1=break enable
4026 	 * 05..04  character length
4027 	 *         00=5 bits
4028 	 *         01=6 bits
4029 	 *         10=7 bits
4030 	 *         11=8 bits
4031 	 * 03      0=1 stop bit, 1=2 stop bits
4032 	 * 02      reset
4033 	 * 01      enable
4034 	 * 00      auto-CTS enable
4035 	 */
4036 	val = 0x4000;
4037 
4038 	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
4039 		val |= BIT7;
4040 
4041 	if (info->params.parity != ASYNC_PARITY_NONE) {
4042 		val |= BIT9;
4043 		if (info->params.parity == ASYNC_PARITY_ODD)
4044 			val |= BIT8;
4045 	}
4046 
4047 	switch (info->params.data_bits)
4048 	{
4049 	case 6: val |= BIT4; break;
4050 	case 7: val |= BIT5; break;
4051 	case 8: val |= BIT5 + BIT4; break;
4052 	}
4053 
4054 	if (info->params.stop_bits != 1)
4055 		val |= BIT3;
4056 
4057 	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
4058 		val |= BIT0;
4059 
4060 	wr_reg16(info, TCR, val);
4061 
4062 	/* RCR (rx control)
4063 	 *
4064 	 * 15..13  mode, 010=async
4065 	 * 12..10  encoding, 000=NRZ
4066 	 * 09      parity enable
4067 	 * 08      1=odd parity, 0=even parity
4068 	 * 07..06  reserved, must be 0
4069 	 * 05..04  character length
4070 	 *         00=5 bits
4071 	 *         01=6 bits
4072 	 *         10=7 bits
4073 	 *         11=8 bits
4074 	 * 03      reserved, must be zero
4075 	 * 02      reset
4076 	 * 01      enable
4077 	 * 00      auto-DCD enable
4078 	 */
4079 	val = 0x4000;
4080 
4081 	if (info->params.parity != ASYNC_PARITY_NONE) {
4082 		val |= BIT9;
4083 		if (info->params.parity == ASYNC_PARITY_ODD)
4084 			val |= BIT8;
4085 	}
4086 
4087 	switch (info->params.data_bits)
4088 	{
4089 	case 6: val |= BIT4; break;
4090 	case 7: val |= BIT5; break;
4091 	case 8: val |= BIT5 + BIT4; break;
4092 	}
4093 
4094 	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
4095 		val |= BIT0;
4096 
4097 	wr_reg16(info, RCR, val);
4098 
4099 	/* CCR (clock control)
4100 	 *
4101 	 * 07..05  011 = tx clock source is BRG/16
4102 	 * 04..02  010 = rx clock source is BRG
4103 	 * 01      0 = auxclk disabled
4104 	 * 00      1 = BRG enabled
4105 	 *
4106 	 * 0110 1001
4107 	 */
4108 	wr_reg8(info, CCR, 0x69);
4109 
4110 	msc_set_vcr(info);
4111 
4112 	/* SCR (serial control)
4113 	 *
4114 	 * 15  1=tx req on FIFO half empty
4115 	 * 14  1=rx req on FIFO half full
4116 	 * 13  tx data  IRQ enable
4117 	 * 12  tx idle  IRQ enable
4118 	 * 11  rx break on IRQ enable
4119 	 * 10  rx data  IRQ enable
4120 	 * 09  rx break off IRQ enable
4121 	 * 08  overrun  IRQ enable
4122 	 * 07  DSR      IRQ enable
4123 	 * 06  CTS      IRQ enable
4124 	 * 05  DCD      IRQ enable
4125 	 * 04  RI       IRQ enable
4126 	 * 03  0=16x sampling, 1=8x sampling
4127 	 * 02  1=txd->rxd internal loopback enable
4128 	 * 01  reserved, must be zero
4129 	 * 00  1=master IRQ enable
4130 	 */
4131 	val = BIT15 + BIT14 + BIT0;
4132 	/* JCR[8] : 1 = x8 async mode feature available */
4133 	if ((rd_reg32(info, JCR) & BIT8) && info->params.data_rate &&
4134 	    ((info->base_clock < (info->params.data_rate * 16)) ||
4135 	     (info->base_clock % (info->params.data_rate * 16)))) {
4136 		/* use 8x sampling */
4137 		val |= BIT3;
4138 		set_rate(info, info->params.data_rate * 8);
4139 	} else {
4140 		/* use 16x sampling */
4141 		set_rate(info, info->params.data_rate * 16);
4142 	}
4143 	wr_reg16(info, SCR, val);
4144 
4145 	slgt_irq_on(info, IRQ_RXBREAK | IRQ_RXOVER);
4146 
4147 	if (info->params.loopback)
4148 		enable_loopback(info);
4149 }
4150 
4151 static void sync_mode(struct slgt_info *info)
4152 {
4153 	unsigned short val;
4154 
4155 	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
4156 	tx_stop(info);
4157 	rx_stop(info);
4158 
4159 	/* TCR (tx control)
4160 	 *
4161 	 * 15..13  mode
4162 	 *         000=HDLC/SDLC
4163 	 *         001=raw bit synchronous
4164 	 *         010=asynchronous/isochronous
4165 	 *         011=monosync byte synchronous
4166 	 *         100=bisync byte synchronous
4167 	 *         101=xsync byte synchronous
4168 	 * 12..10  encoding
4169 	 * 09      CRC enable
4170 	 * 08      CRC32
4171 	 * 07      1=RTS driver control
4172 	 * 06      preamble enable
4173 	 * 05..04  preamble length
4174 	 * 03      share open/close flag
4175 	 * 02      reset
4176 	 * 01      enable
4177 	 * 00      auto-CTS enable
4178 	 */
4179 	val = BIT2;
4180 
4181 	switch(info->params.mode) {
4182 	case MGSL_MODE_XSYNC:
4183 		val |= BIT15 + BIT13;
4184 		break;
4185 	case MGSL_MODE_MONOSYNC: val |= BIT14 + BIT13; break;
4186 	case MGSL_MODE_BISYNC:   val |= BIT15; break;
4187 	case MGSL_MODE_RAW:      val |= BIT13; break;
4188 	}
4189 	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
4190 		val |= BIT7;
4191 
4192 	switch(info->params.encoding)
4193 	{
4194 	case HDLC_ENCODING_NRZB:          val |= BIT10; break;
4195 	case HDLC_ENCODING_NRZI_MARK:     val |= BIT11; break;
4196 	case HDLC_ENCODING_NRZI:          val |= BIT11 + BIT10; break;
4197 	case HDLC_ENCODING_BIPHASE_MARK:  val |= BIT12; break;
4198 	case HDLC_ENCODING_BIPHASE_SPACE: val |= BIT12 + BIT10; break;
4199 	case HDLC_ENCODING_BIPHASE_LEVEL: val |= BIT12 + BIT11; break;
4200 	case HDLC_ENCODING_DIFF_BIPHASE_LEVEL: val |= BIT12 + BIT11 + BIT10; break;
4201 	}
4202 
4203 	switch (info->params.crc_type & HDLC_CRC_MASK)
4204 	{
4205 	case HDLC_CRC_16_CCITT: val |= BIT9; break;
4206 	case HDLC_CRC_32_CCITT: val |= BIT9 + BIT8; break;
4207 	}
4208 
4209 	if (info->params.preamble != HDLC_PREAMBLE_PATTERN_NONE)
4210 		val |= BIT6;
4211 
4212 	switch (info->params.preamble_length)
4213 	{
4214 	case HDLC_PREAMBLE_LENGTH_16BITS: val |= BIT5; break;
4215 	case HDLC_PREAMBLE_LENGTH_32BITS: val |= BIT4; break;
4216 	case HDLC_PREAMBLE_LENGTH_64BITS: val |= BIT5 + BIT4; break;
4217 	}
4218 
4219 	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
4220 		val |= BIT0;
4221 
4222 	wr_reg16(info, TCR, val);
4223 
4224 	/* TPR (transmit preamble) */
4225 
4226 	switch (info->params.preamble)
4227 	{
4228 	case HDLC_PREAMBLE_PATTERN_FLAGS: val = 0x7e; break;
4229 	case HDLC_PREAMBLE_PATTERN_ONES:  val = 0xff; break;
4230 	case HDLC_PREAMBLE_PATTERN_ZEROS: val = 0x00; break;
4231 	case HDLC_PREAMBLE_PATTERN_10:    val = 0x55; break;
4232 	case HDLC_PREAMBLE_PATTERN_01:    val = 0xaa; break;
4233 	default:                          val = 0x7e; break;
4234 	}
4235 	wr_reg8(info, TPR, (unsigned char)val);
4236 
4237 	/* RCR (rx control)
4238 	 *
4239 	 * 15..13  mode
4240 	 *         000=HDLC/SDLC
4241 	 *         001=raw bit synchronous
4242 	 *         010=asynchronous/isochronous
4243 	 *         011=monosync byte synchronous
4244 	 *         100=bisync byte synchronous
4245 	 *         101=xsync byte synchronous
4246 	 * 12..10  encoding
4247 	 * 09      CRC enable
4248 	 * 08      CRC32
4249 	 * 07..03  reserved, must be 0
4250 	 * 02      reset
4251 	 * 01      enable
4252 	 * 00      auto-DCD enable
4253 	 */
4254 	val = 0;
4255 
4256 	switch(info->params.mode) {
4257 	case MGSL_MODE_XSYNC:
4258 		val |= BIT15 + BIT13;
4259 		break;
4260 	case MGSL_MODE_MONOSYNC: val |= BIT14 + BIT13; break;
4261 	case MGSL_MODE_BISYNC:   val |= BIT15; break;
4262 	case MGSL_MODE_RAW:      val |= BIT13; break;
4263 	}
4264 
4265 	switch(info->params.encoding)
4266 	{
4267 	case HDLC_ENCODING_NRZB:          val |= BIT10; break;
4268 	case HDLC_ENCODING_NRZI_MARK:     val |= BIT11; break;
4269 	case HDLC_ENCODING_NRZI:          val |= BIT11 + BIT10; break;
4270 	case HDLC_ENCODING_BIPHASE_MARK:  val |= BIT12; break;
4271 	case HDLC_ENCODING_BIPHASE_SPACE: val |= BIT12 + BIT10; break;
4272 	case HDLC_ENCODING_BIPHASE_LEVEL: val |= BIT12 + BIT11; break;
4273 	case HDLC_ENCODING_DIFF_BIPHASE_LEVEL: val |= BIT12 + BIT11 + BIT10; break;
4274 	}
4275 
4276 	switch (info->params.crc_type & HDLC_CRC_MASK)
4277 	{
4278 	case HDLC_CRC_16_CCITT: val |= BIT9; break;
4279 	case HDLC_CRC_32_CCITT: val |= BIT9 + BIT8; break;
4280 	}
4281 
4282 	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
4283 		val |= BIT0;
4284 
4285 	wr_reg16(info, RCR, val);
4286 
4287 	/* CCR (clock control)
4288 	 *
4289 	 * 07..05  tx clock source
4290 	 * 04..02  rx clock source
4291 	 * 01      auxclk enable
4292 	 * 00      BRG enable
4293 	 */
4294 	val = 0;
4295 
4296 	if (info->params.flags & HDLC_FLAG_TXC_BRG)
4297 	{
4298 		// when RxC source is DPLL, BRG generates 16X DPLL
4299 		// reference clock, so take TxC from BRG/16 to get
4300 		// transmit clock at actual data rate
4301 		if (info->params.flags & HDLC_FLAG_RXC_DPLL)
4302 			val |= BIT6 + BIT5;	/* 011, txclk = BRG/16 */
4303 		else
4304 			val |= BIT6;	/* 010, txclk = BRG */
4305 	}
4306 	else if (info->params.flags & HDLC_FLAG_TXC_DPLL)
4307 		val |= BIT7;	/* 100, txclk = DPLL Input */
4308 	else if (info->params.flags & HDLC_FLAG_TXC_RXCPIN)
4309 		val |= BIT5;	/* 001, txclk = RXC Input */
4310 
4311 	if (info->params.flags & HDLC_FLAG_RXC_BRG)
4312 		val |= BIT3;	/* 010, rxclk = BRG */
4313 	else if (info->params.flags & HDLC_FLAG_RXC_DPLL)
4314 		val |= BIT4;	/* 100, rxclk = DPLL */
4315 	else if (info->params.flags & HDLC_FLAG_RXC_TXCPIN)
4316 		val |= BIT2;	/* 001, rxclk = TXC Input */
4317 
4318 	if (info->params.clock_speed)
4319 		val |= BIT1 + BIT0;
4320 
4321 	wr_reg8(info, CCR, (unsigned char)val);
4322 
4323 	if (info->params.flags & (HDLC_FLAG_TXC_DPLL + HDLC_FLAG_RXC_DPLL))
4324 	{
4325 		// program DPLL mode
4326 		switch(info->params.encoding)
4327 		{
4328 		case HDLC_ENCODING_BIPHASE_MARK:
4329 		case HDLC_ENCODING_BIPHASE_SPACE:
4330 			val = BIT7; break;
4331 		case HDLC_ENCODING_BIPHASE_LEVEL:
4332 		case HDLC_ENCODING_DIFF_BIPHASE_LEVEL:
4333 			val = BIT7 + BIT6; break;
4334 		default: val = BIT6;	// NRZ encodings
4335 		}
4336 		wr_reg16(info, RCR, (unsigned short)(rd_reg16(info, RCR) | val));
4337 
4338 		// DPLL requires a 16X reference clock from BRG
4339 		set_rate(info, info->params.clock_speed * 16);
4340 	}
4341 	else
4342 		set_rate(info, info->params.clock_speed);
4343 
4344 	tx_set_idle(info);
4345 
4346 	msc_set_vcr(info);
4347 
4348 	/* SCR (serial control)
4349 	 *
4350 	 * 15  1=tx req on FIFO half empty
4351 	 * 14  1=rx req on FIFO half full
4352 	 * 13  tx data  IRQ enable
4353 	 * 12  tx idle  IRQ enable
4354 	 * 11  underrun IRQ enable
4355 	 * 10  rx data  IRQ enable
4356 	 * 09  rx idle  IRQ enable
4357 	 * 08  overrun  IRQ enable
4358 	 * 07  DSR      IRQ enable
4359 	 * 06  CTS      IRQ enable
4360 	 * 05  DCD      IRQ enable
4361 	 * 04  RI       IRQ enable
4362 	 * 03  reserved, must be zero
4363 	 * 02  1=txd->rxd internal loopback enable
4364 	 * 01  reserved, must be zero
4365 	 * 00  1=master IRQ enable
4366 	 */
4367 	wr_reg16(info, SCR, BIT15 + BIT14 + BIT0);
4368 
4369 	if (info->params.loopback)
4370 		enable_loopback(info);
4371 }
4372 
4373 /*
4374  *  set transmit idle mode
4375  */
4376 static void tx_set_idle(struct slgt_info *info)
4377 {
4378 	unsigned char val;
4379 	unsigned short tcr;
4380 
4381 	/* if preamble enabled (tcr[6] == 1) then tx idle size = 8 bits
4382 	 * else tcr[5:4] = tx idle size: 00 = 8 bits, 01 = 16 bits
4383 	 */
4384 	tcr = rd_reg16(info, TCR);
4385 	if (info->idle_mode & HDLC_TXIDLE_CUSTOM_16) {
4386 		/* disable preamble, set idle size to 16 bits */
4387 		tcr = (tcr & ~(BIT6 + BIT5)) | BIT4;
4388 		/* MSB of 16 bit idle specified in tx preamble register (TPR) */
4389 		wr_reg8(info, TPR, (unsigned char)((info->idle_mode >> 8) & 0xff));
4390 	} else if (!(tcr & BIT6)) {
4391 		/* preamble is disabled, set idle size to 8 bits */
4392 		tcr &= ~(BIT5 + BIT4);
4393 	}
4394 	wr_reg16(info, TCR, tcr);
4395 
4396 	if (info->idle_mode & (HDLC_TXIDLE_CUSTOM_8 | HDLC_TXIDLE_CUSTOM_16)) {
4397 		/* LSB of custom tx idle specified in tx idle register */
4398 		val = (unsigned char)(info->idle_mode & 0xff);
4399 	} else {
4400 		/* standard 8 bit idle patterns */
4401 		switch(info->idle_mode)
4402 		{
4403 		case HDLC_TXIDLE_FLAGS:          val = 0x7e; break;
4404 		case HDLC_TXIDLE_ALT_ZEROS_ONES:
4405 		case HDLC_TXIDLE_ALT_MARK_SPACE: val = 0xaa; break;
4406 		case HDLC_TXIDLE_ZEROS:
4407 		case HDLC_TXIDLE_SPACE:          val = 0x00; break;
4408 		default:                         val = 0xff;
4409 		}
4410 	}
4411 
4412 	wr_reg8(info, TIR, val);
4413 }
4414 
4415 /*
4416  * get state of V24 status (input) signals
4417  */
4418 static void get_gtsignals(struct slgt_info *info)
4419 {
4420 	unsigned short status = rd_reg16(info, SSR);
4421 
4422 	/* clear all serial signals except RTS and DTR */
4423 	info->signals &= SerialSignal_RTS | SerialSignal_DTR;
4424 
4425 	if (status & BIT3)
4426 		info->signals |= SerialSignal_DSR;
4427 	if (status & BIT2)
4428 		info->signals |= SerialSignal_CTS;
4429 	if (status & BIT1)
4430 		info->signals |= SerialSignal_DCD;
4431 	if (status & BIT0)
4432 		info->signals |= SerialSignal_RI;
4433 }
4434 
4435 /*
4436  * set V.24 Control Register based on current configuration
4437  */
4438 static void msc_set_vcr(struct slgt_info *info)
4439 {
4440 	unsigned char val = 0;
4441 
4442 	/* VCR (V.24 control)
4443 	 *
4444 	 * 07..04  serial IF select
4445 	 * 03      DTR
4446 	 * 02      RTS
4447 	 * 01      LL
4448 	 * 00      RL
4449 	 */
4450 
4451 	switch(info->if_mode & MGSL_INTERFACE_MASK)
4452 	{
4453 	case MGSL_INTERFACE_RS232:
4454 		val |= BIT5; /* 0010 */
4455 		break;
4456 	case MGSL_INTERFACE_V35:
4457 		val |= BIT7 + BIT6 + BIT5; /* 1110 */
4458 		break;
4459 	case MGSL_INTERFACE_RS422:
4460 		val |= BIT6; /* 0100 */
4461 		break;
4462 	}
4463 
4464 	if (info->if_mode & MGSL_INTERFACE_MSB_FIRST)
4465 		val |= BIT4;
4466 	if (info->signals & SerialSignal_DTR)
4467 		val |= BIT3;
4468 	if (info->signals & SerialSignal_RTS)
4469 		val |= BIT2;
4470 	if (info->if_mode & MGSL_INTERFACE_LL)
4471 		val |= BIT1;
4472 	if (info->if_mode & MGSL_INTERFACE_RL)
4473 		val |= BIT0;
4474 	wr_reg8(info, VCR, val);
4475 }
4476 
4477 /*
4478  * set state of V24 control (output) signals
4479  */
4480 static void set_gtsignals(struct slgt_info *info)
4481 {
4482 	unsigned char val = rd_reg8(info, VCR);
4483 	if (info->signals & SerialSignal_DTR)
4484 		val |= BIT3;
4485 	else
4486 		val &= ~BIT3;
4487 	if (info->signals & SerialSignal_RTS)
4488 		val |= BIT2;
4489 	else
4490 		val &= ~BIT2;
4491 	wr_reg8(info, VCR, val);
4492 }
4493 
4494 /*
4495  * free range of receive DMA buffers (i to last)
4496  */
4497 static void free_rbufs(struct slgt_info *info, unsigned int i, unsigned int last)
4498 {
4499 	int done = 0;
4500 
4501 	while(!done) {
4502 		/* reset current buffer for reuse */
4503 		info->rbufs[i].status = 0;
4504 		set_desc_count(info->rbufs[i], info->rbuf_fill_level);
4505 		if (i == last)
4506 			done = 1;
4507 		if (++i == info->rbuf_count)
4508 			i = 0;
4509 	}
4510 	info->rbuf_current = i;
4511 }
4512 
4513 /*
4514  * mark all receive DMA buffers as free
4515  */
4516 static void reset_rbufs(struct slgt_info *info)
4517 {
4518 	free_rbufs(info, 0, info->rbuf_count - 1);
4519 	info->rbuf_fill_index = 0;
4520 	info->rbuf_fill_count = 0;
4521 }
4522 
4523 /*
4524  * pass receive HDLC frame to upper layer
4525  *
4526  * return true if frame available, otherwise false
4527  */
4528 static bool rx_get_frame(struct slgt_info *info)
4529 {
4530 	unsigned int start, end;
4531 	unsigned short status;
4532 	unsigned int framesize = 0;
4533 	unsigned long flags;
4534 	struct tty_struct *tty = info->port.tty;
4535 	unsigned char addr_field = 0xff;
4536 	unsigned int crc_size = 0;
4537 
4538 	switch (info->params.crc_type & HDLC_CRC_MASK) {
4539 	case HDLC_CRC_16_CCITT: crc_size = 2; break;
4540 	case HDLC_CRC_32_CCITT: crc_size = 4; break;
4541 	}
4542 
4543 check_again:
4544 
4545 	framesize = 0;
4546 	addr_field = 0xff;
4547 	start = end = info->rbuf_current;
4548 
4549 	for (;;) {
4550 		if (!desc_complete(info->rbufs[end]))
4551 			goto cleanup;
4552 
4553 		if (framesize == 0 && info->params.addr_filter != 0xff)
4554 			addr_field = info->rbufs[end].buf[0];
4555 
4556 		framesize += desc_count(info->rbufs[end]);
4557 
4558 		if (desc_eof(info->rbufs[end]))
4559 			break;
4560 
4561 		if (++end == info->rbuf_count)
4562 			end = 0;
4563 
4564 		if (end == info->rbuf_current) {
4565 			if (info->rx_enabled){
4566 				spin_lock_irqsave(&info->lock,flags);
4567 				rx_start(info);
4568 				spin_unlock_irqrestore(&info->lock,flags);
4569 			}
4570 			goto cleanup;
4571 		}
4572 	}
4573 
4574 	/* status
4575 	 *
4576 	 * 15      buffer complete
4577 	 * 14..06  reserved
4578 	 * 05..04  residue
4579 	 * 02      eof (end of frame)
4580 	 * 01      CRC error
4581 	 * 00      abort
4582 	 */
4583 	status = desc_status(info->rbufs[end]);
4584 
4585 	/* ignore CRC bit if not using CRC (bit is undefined) */
4586 	if ((info->params.crc_type & HDLC_CRC_MASK) == HDLC_CRC_NONE)
4587 		status &= ~BIT1;
4588 
4589 	if (framesize == 0 ||
4590 		 (addr_field != 0xff && addr_field != info->params.addr_filter)) {
4591 		free_rbufs(info, start, end);
4592 		goto check_again;
4593 	}
4594 
4595 	if (framesize < (2 + crc_size) || status & BIT0) {
4596 		info->icount.rxshort++;
4597 		framesize = 0;
4598 	} else if (status & BIT1) {
4599 		info->icount.rxcrc++;
4600 		if (!(info->params.crc_type & HDLC_CRC_RETURN_EX))
4601 			framesize = 0;
4602 	}
4603 
4604 #if SYNCLINK_GENERIC_HDLC
4605 	if (framesize == 0) {
4606 		info->netdev->stats.rx_errors++;
4607 		info->netdev->stats.rx_frame_errors++;
4608 	}
4609 #endif
4610 
4611 	DBGBH(("%s rx frame status=%04X size=%d\n",
4612 		info->device_name, status, framesize));
4613 	DBGDATA(info, info->rbufs[start].buf, min_t(int, framesize, info->rbuf_fill_level), "rx");
4614 
4615 	if (framesize) {
4616 		if (!(info->params.crc_type & HDLC_CRC_RETURN_EX)) {
4617 			framesize -= crc_size;
4618 			crc_size = 0;
4619 		}
4620 
4621 		if (framesize > info->max_frame_size + crc_size)
4622 			info->icount.rxlong++;
4623 		else {
4624 			/* copy dma buffer(s) to contiguous temp buffer */
4625 			int copy_count = framesize;
4626 			int i = start;
4627 			unsigned char *p = info->tmp_rbuf;
4628 			info->tmp_rbuf_count = framesize;
4629 
4630 			info->icount.rxok++;
4631 
4632 			while(copy_count) {
4633 				int partial_count = min_t(int, copy_count, info->rbuf_fill_level);
4634 				memcpy(p, info->rbufs[i].buf, partial_count);
4635 				p += partial_count;
4636 				copy_count -= partial_count;
4637 				if (++i == info->rbuf_count)
4638 					i = 0;
4639 			}
4640 
4641 			if (info->params.crc_type & HDLC_CRC_RETURN_EX) {
4642 				*p = (status & BIT1) ? RX_CRC_ERROR : RX_OK;
4643 				framesize++;
4644 			}
4645 
4646 #if SYNCLINK_GENERIC_HDLC
4647 			if (info->netcount)
4648 				hdlcdev_rx(info,info->tmp_rbuf, framesize);
4649 			else
4650 #endif
4651 				ldisc_receive_buf(tty, info->tmp_rbuf, NULL,
4652 						  framesize);
4653 		}
4654 	}
4655 	free_rbufs(info, start, end);
4656 	return true;
4657 
4658 cleanup:
4659 	return false;
4660 }
4661 
4662 /*
4663  * pass receive buffer (RAW synchronous mode) to tty layer
4664  * return true if buffer available, otherwise false
4665  */
4666 static bool rx_get_buf(struct slgt_info *info)
4667 {
4668 	unsigned int i = info->rbuf_current;
4669 	unsigned int count;
4670 
4671 	if (!desc_complete(info->rbufs[i]))
4672 		return false;
4673 	count = desc_count(info->rbufs[i]);
4674 	switch(info->params.mode) {
4675 	case MGSL_MODE_MONOSYNC:
4676 	case MGSL_MODE_BISYNC:
4677 	case MGSL_MODE_XSYNC:
4678 		/* ignore residue in byte synchronous modes */
4679 		if (desc_residue(info->rbufs[i]))
4680 			count--;
4681 		break;
4682 	}
4683 	DBGDATA(info, info->rbufs[i].buf, count, "rx");
4684 	DBGINFO(("rx_get_buf size=%d\n", count));
4685 	if (count)
4686 		ldisc_receive_buf(info->port.tty, info->rbufs[i].buf, NULL,
4687 				  count);
4688 	free_rbufs(info, i, i);
4689 	return true;
4690 }
4691 
4692 static void reset_tbufs(struct slgt_info *info)
4693 {
4694 	unsigned int i;
4695 	info->tbuf_current = 0;
4696 	for (i=0 ; i < info->tbuf_count ; i++) {
4697 		info->tbufs[i].status = 0;
4698 		info->tbufs[i].count  = 0;
4699 	}
4700 }
4701 
4702 /*
4703  * return number of free transmit DMA buffers
4704  */
4705 static unsigned int free_tbuf_count(struct slgt_info *info)
4706 {
4707 	unsigned int count = 0;
4708 	unsigned int i = info->tbuf_current;
4709 
4710 	do
4711 	{
4712 		if (desc_count(info->tbufs[i]))
4713 			break; /* buffer in use */
4714 		++count;
4715 		if (++i == info->tbuf_count)
4716 			i=0;
4717 	} while (i != info->tbuf_current);
4718 
4719 	/* if tx DMA active, last zero count buffer is in use */
4720 	if (count && (rd_reg32(info, TDCSR) & BIT0))
4721 		--count;
4722 
4723 	return count;
4724 }
4725 
4726 /*
4727  * return number of bytes in unsent transmit DMA buffers
4728  * and the serial controller tx FIFO
4729  */
4730 static unsigned int tbuf_bytes(struct slgt_info *info)
4731 {
4732 	unsigned int total_count = 0;
4733 	unsigned int i = info->tbuf_current;
4734 	unsigned int reg_value;
4735 	unsigned int count;
4736 	unsigned int active_buf_count = 0;
4737 
4738 	/*
4739 	 * Add descriptor counts for all tx DMA buffers.
4740 	 * If count is zero (cleared by DMA controller after read),
4741 	 * the buffer is complete or is actively being read from.
4742 	 *
4743 	 * Record buf_count of last buffer with zero count starting
4744 	 * from current ring position. buf_count is mirror
4745 	 * copy of count and is not cleared by serial controller.
4746 	 * If DMA controller is active, that buffer is actively
4747 	 * being read so add to total.
4748 	 */
4749 	do {
4750 		count = desc_count(info->tbufs[i]);
4751 		if (count)
4752 			total_count += count;
4753 		else if (!total_count)
4754 			active_buf_count = info->tbufs[i].buf_count;
4755 		if (++i == info->tbuf_count)
4756 			i = 0;
4757 	} while (i != info->tbuf_current);
4758 
4759 	/* read tx DMA status register */
4760 	reg_value = rd_reg32(info, TDCSR);
4761 
4762 	/* if tx DMA active, last zero count buffer is in use */
4763 	if (reg_value & BIT0)
4764 		total_count += active_buf_count;
4765 
4766 	/* add tx FIFO count = reg_value[15..8] */
4767 	total_count += (reg_value >> 8) & 0xff;
4768 
4769 	/* if transmitter active add one byte for shift register */
4770 	if (info->tx_active)
4771 		total_count++;
4772 
4773 	return total_count;
4774 }
4775 
4776 /*
4777  * load data into transmit DMA buffer ring and start transmitter if needed
4778  * return true if data accepted, otherwise false (buffers full)
4779  */
4780 static bool tx_load(struct slgt_info *info, const char *buf, unsigned int size)
4781 {
4782 	unsigned short count;
4783 	unsigned int i;
4784 	struct slgt_desc *d;
4785 
4786 	/* check required buffer space */
4787 	if (DIV_ROUND_UP(size, DMABUFSIZE) > free_tbuf_count(info))
4788 		return false;
4789 
4790 	DBGDATA(info, buf, size, "tx");
4791 
4792 	/*
4793 	 * copy data to one or more DMA buffers in circular ring
4794 	 * tbuf_start   = first buffer for this data
4795 	 * tbuf_current = next free buffer
4796 	 *
4797 	 * Copy all data before making data visible to DMA controller by
4798 	 * setting descriptor count of the first buffer.
4799 	 * This prevents an active DMA controller from reading the first DMA
4800 	 * buffers of a frame and stopping before the final buffers are filled.
4801 	 */
4802 
4803 	info->tbuf_start = i = info->tbuf_current;
4804 
4805 	while (size) {
4806 		d = &info->tbufs[i];
4807 
4808 		count = (unsigned short)((size > DMABUFSIZE) ? DMABUFSIZE : size);
4809 		memcpy(d->buf, buf, count);
4810 
4811 		size -= count;
4812 		buf  += count;
4813 
4814 		/*
4815 		 * set EOF bit for last buffer of HDLC frame or
4816 		 * for every buffer in raw mode
4817 		 */
4818 		if ((!size && info->params.mode == MGSL_MODE_HDLC) ||
4819 		    info->params.mode == MGSL_MODE_RAW)
4820 			set_desc_eof(*d, 1);
4821 		else
4822 			set_desc_eof(*d, 0);
4823 
4824 		/* set descriptor count for all but first buffer */
4825 		if (i != info->tbuf_start)
4826 			set_desc_count(*d, count);
4827 		d->buf_count = count;
4828 
4829 		if (++i == info->tbuf_count)
4830 			i = 0;
4831 	}
4832 
4833 	info->tbuf_current = i;
4834 
4835 	/* set first buffer count to make new data visible to DMA controller */
4836 	d = &info->tbufs[info->tbuf_start];
4837 	set_desc_count(*d, d->buf_count);
4838 
4839 	/* start transmitter if needed and update transmit timeout */
4840 	if (!info->tx_active)
4841 		tx_start(info);
4842 	update_tx_timer(info);
4843 
4844 	return true;
4845 }
4846 
4847 static int register_test(struct slgt_info *info)
4848 {
4849 	static unsigned short patterns[] =
4850 		{0x0000, 0xffff, 0xaaaa, 0x5555, 0x6969, 0x9696};
4851 	static unsigned int count = ARRAY_SIZE(patterns);
4852 	unsigned int i;
4853 	int rc = 0;
4854 
4855 	for (i=0 ; i < count ; i++) {
4856 		wr_reg16(info, TIR, patterns[i]);
4857 		wr_reg16(info, BDR, patterns[(i+1)%count]);
4858 		if ((rd_reg16(info, TIR) != patterns[i]) ||
4859 		    (rd_reg16(info, BDR) != patterns[(i+1)%count])) {
4860 			rc = -ENODEV;
4861 			break;
4862 		}
4863 	}
4864 	info->gpio_present = (rd_reg32(info, JCR) & BIT5) ? 1 : 0;
4865 	info->init_error = rc ? 0 : DiagStatus_AddressFailure;
4866 	return rc;
4867 }
4868 
4869 static int irq_test(struct slgt_info *info)
4870 {
4871 	unsigned long timeout;
4872 	unsigned long flags;
4873 	struct tty_struct *oldtty = info->port.tty;
4874 	u32 speed = info->params.data_rate;
4875 
4876 	info->params.data_rate = 921600;
4877 	info->port.tty = NULL;
4878 
4879 	spin_lock_irqsave(&info->lock, flags);
4880 	async_mode(info);
4881 	slgt_irq_on(info, IRQ_TXIDLE);
4882 
4883 	/* enable transmitter */
4884 	wr_reg16(info, TCR,
4885 		(unsigned short)(rd_reg16(info, TCR) | BIT1));
4886 
4887 	/* write one byte and wait for tx idle */
4888 	wr_reg16(info, TDR, 0);
4889 
4890 	/* assume failure */
4891 	info->init_error = DiagStatus_IrqFailure;
4892 	info->irq_occurred = false;
4893 
4894 	spin_unlock_irqrestore(&info->lock, flags);
4895 
4896 	timeout=100;
4897 	while(timeout-- && !info->irq_occurred)
4898 		msleep_interruptible(10);
4899 
4900 	spin_lock_irqsave(&info->lock,flags);
4901 	reset_port(info);
4902 	spin_unlock_irqrestore(&info->lock,flags);
4903 
4904 	info->params.data_rate = speed;
4905 	info->port.tty = oldtty;
4906 
4907 	info->init_error = info->irq_occurred ? 0 : DiagStatus_IrqFailure;
4908 	return info->irq_occurred ? 0 : -ENODEV;
4909 }
4910 
4911 static int loopback_test_rx(struct slgt_info *info)
4912 {
4913 	unsigned char *src, *dest;
4914 	int count;
4915 
4916 	if (desc_complete(info->rbufs[0])) {
4917 		count = desc_count(info->rbufs[0]);
4918 		src   = info->rbufs[0].buf;
4919 		dest  = info->tmp_rbuf;
4920 
4921 		for( ; count ; count-=2, src+=2) {
4922 			/* src=data byte (src+1)=status byte */
4923 			if (!(*(src+1) & (BIT9 + BIT8))) {
4924 				*dest = *src;
4925 				dest++;
4926 				info->tmp_rbuf_count++;
4927 			}
4928 		}
4929 		DBGDATA(info, info->tmp_rbuf, info->tmp_rbuf_count, "rx");
4930 		return 1;
4931 	}
4932 	return 0;
4933 }
4934 
4935 static int loopback_test(struct slgt_info *info)
4936 {
4937 #define TESTFRAMESIZE 20
4938 
4939 	unsigned long timeout;
4940 	u16 count;
4941 	unsigned char buf[TESTFRAMESIZE];
4942 	int rc = -ENODEV;
4943 	unsigned long flags;
4944 
4945 	struct tty_struct *oldtty = info->port.tty;
4946 	MGSL_PARAMS params;
4947 
4948 	memcpy(&params, &info->params, sizeof(params));
4949 
4950 	info->params.mode = MGSL_MODE_ASYNC;
4951 	info->params.data_rate = 921600;
4952 	info->params.loopback = 1;
4953 	info->port.tty = NULL;
4954 
4955 	/* build and send transmit frame */
4956 	for (count = 0; count < TESTFRAMESIZE; ++count)
4957 		buf[count] = (unsigned char)count;
4958 
4959 	info->tmp_rbuf_count = 0;
4960 	memset(info->tmp_rbuf, 0, TESTFRAMESIZE);
4961 
4962 	/* program hardware for HDLC and enabled receiver */
4963 	spin_lock_irqsave(&info->lock,flags);
4964 	async_mode(info);
4965 	rx_start(info);
4966 	tx_load(info, buf, count);
4967 	spin_unlock_irqrestore(&info->lock, flags);
4968 
4969 	/* wait for receive complete */
4970 	for (timeout = 100; timeout; --timeout) {
4971 		msleep_interruptible(10);
4972 		if (loopback_test_rx(info)) {
4973 			rc = 0;
4974 			break;
4975 		}
4976 	}
4977 
4978 	/* verify received frame length and contents */
4979 	if (!rc && (info->tmp_rbuf_count != count ||
4980 		  memcmp(buf, info->tmp_rbuf, count))) {
4981 		rc = -ENODEV;
4982 	}
4983 
4984 	spin_lock_irqsave(&info->lock,flags);
4985 	reset_adapter(info);
4986 	spin_unlock_irqrestore(&info->lock,flags);
4987 
4988 	memcpy(&info->params, &params, sizeof(info->params));
4989 	info->port.tty = oldtty;
4990 
4991 	info->init_error = rc ? DiagStatus_DmaFailure : 0;
4992 	return rc;
4993 }
4994 
4995 static int adapter_test(struct slgt_info *info)
4996 {
4997 	DBGINFO(("testing %s\n", info->device_name));
4998 	if (register_test(info) < 0) {
4999 		printk("register test failure %s addr=%08X\n",
5000 			info->device_name, info->phys_reg_addr);
5001 	} else if (irq_test(info) < 0) {
5002 		printk("IRQ test failure %s IRQ=%d\n",
5003 			info->device_name, info->irq_level);
5004 	} else if (loopback_test(info) < 0) {
5005 		printk("loopback test failure %s\n", info->device_name);
5006 	}
5007 	return info->init_error;
5008 }
5009 
5010 /*
5011  * transmit timeout handler
5012  */
5013 static void tx_timeout(struct timer_list *t)
5014 {
5015 	struct slgt_info *info = from_timer(info, t, tx_timer);
5016 	unsigned long flags;
5017 
5018 	DBGINFO(("%s tx_timeout\n", info->device_name));
5019 	if(info->tx_active && info->params.mode == MGSL_MODE_HDLC) {
5020 		info->icount.txtimeout++;
5021 	}
5022 	spin_lock_irqsave(&info->lock,flags);
5023 	tx_stop(info);
5024 	spin_unlock_irqrestore(&info->lock,flags);
5025 
5026 #if SYNCLINK_GENERIC_HDLC
5027 	if (info->netcount)
5028 		hdlcdev_tx_done(info);
5029 	else
5030 #endif
5031 		bh_transmit(info);
5032 }
5033 
5034 /*
5035  * receive buffer polling timer
5036  */
5037 static void rx_timeout(struct timer_list *t)
5038 {
5039 	struct slgt_info *info = from_timer(info, t, rx_timer);
5040 	unsigned long flags;
5041 
5042 	DBGINFO(("%s rx_timeout\n", info->device_name));
5043 	spin_lock_irqsave(&info->lock, flags);
5044 	info->pending_bh |= BH_RECEIVE;
5045 	spin_unlock_irqrestore(&info->lock, flags);
5046 	bh_handler(&info->task);
5047 }
5048 
5049