xref: /linux/drivers/tty/mxser.c (revision bb5b94f5bbe75470912b70fb08880fc5273aa62d)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *          mxser.c  -- MOXA Smartio/Industio family multiport serial driver.
4  *
5  *      Copyright (C) 1999-2006  Moxa Technologies (support@moxa.com).
6  *	Copyright (C) 2006-2008  Jiri Slaby <jirislaby@gmail.com>
7  *
8  *      This code is loosely based on the 1.8 moxa driver which is based on
9  *	Linux serial driver, written by Linus Torvalds, Theodore T'so and
10  *	others.
11  *
12  *	Fed through a cleanup, indent and remove of non 2.6 code by Alan Cox
13  *	<alan@lxorguk.ukuu.org.uk>. The original 1.8 code is available on
14  *	www.moxa.com.
15  *	- Fixed x86_64 cleanness
16  */
17 
18 #include <linux/module.h>
19 #include <linux/errno.h>
20 #include <linux/signal.h>
21 #include <linux/sched.h>
22 #include <linux/timer.h>
23 #include <linux/interrupt.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/serial.h>
27 #include <linux/serial_reg.h>
28 #include <linux/major.h>
29 #include <linux/string.h>
30 #include <linux/fcntl.h>
31 #include <linux/ptrace.h>
32 #include <linux/ioport.h>
33 #include <linux/mm.h>
34 #include <linux/delay.h>
35 #include <linux/pci.h>
36 #include <linux/bitops.h>
37 #include <linux/slab.h>
38 #include <linux/ratelimit.h>
39 
40 #include <asm/io.h>
41 #include <asm/irq.h>
42 #include <linux/uaccess.h>
43 
44 /*
45  *	Semi-public control interfaces
46  */
47 
48 /*
49  *	MOXA ioctls
50  */
51 
52 #define MOXA			0x400
53 #define MOXA_SET_OP_MODE	(MOXA + 66)
54 #define MOXA_GET_OP_MODE	(MOXA + 67)
55 
56 #define RS232_MODE		0
57 #define RS485_2WIRE_MODE	1
58 #define RS422_MODE		2
59 #define RS485_4WIRE_MODE	3
60 #define OP_MODE_MASK		3
61 
62 /* --------------------------------------------------- */
63 
64 /*
65  * Follow just what Moxa Must chip defines.
66  *
67  * When LCR register (offset 0x03) is written the following value, the Must chip
68  * will enter enhanced mode. And a write to EFR (offset 0x02) bit 6,7 will
69  * change bank.
70  */
71 #define MOXA_MUST_ENTER_ENHANCED	0xBF
72 
73 /* when enhanced mode is enabled, access to general bank register */
74 #define MOXA_MUST_GDL_REGISTER		0x07
75 #define MOXA_MUST_GDL_MASK		0x7F
76 #define MOXA_MUST_GDL_HAS_BAD_DATA	0x80
77 
78 #define MOXA_MUST_LSR_RERR		0x80	/* error in receive FIFO */
79 /* enhanced register bank select and enhanced mode setting register */
80 /* This works only when LCR register equals to 0xBF */
81 #define MOXA_MUST_EFR_REGISTER		0x02
82 #define MOXA_MUST_EFR_EFRB_ENABLE	0x10 /* enhanced mode enable */
83 /* enhanced register bank set 0, 1, 2 */
84 #define MOXA_MUST_EFR_BANK0		0x00
85 #define MOXA_MUST_EFR_BANK1		0x40
86 #define MOXA_MUST_EFR_BANK2		0x80
87 #define MOXA_MUST_EFR_BANK3		0xC0
88 #define MOXA_MUST_EFR_BANK_MASK		0xC0
89 
90 /* set XON1 value register, when LCR=0xBF and change to bank0 */
91 #define MOXA_MUST_XON1_REGISTER		0x04
92 
93 /* set XON2 value register, when LCR=0xBF and change to bank0 */
94 #define MOXA_MUST_XON2_REGISTER		0x05
95 
96 /* set XOFF1 value register, when LCR=0xBF and change to bank0 */
97 #define MOXA_MUST_XOFF1_REGISTER	0x06
98 
99 /* set XOFF2 value register, when LCR=0xBF and change to bank0 */
100 #define MOXA_MUST_XOFF2_REGISTER	0x07
101 
102 #define MOXA_MUST_RBRTL_REGISTER	0x04
103 #define MOXA_MUST_RBRTH_REGISTER	0x05
104 #define MOXA_MUST_RBRTI_REGISTER	0x06
105 #define MOXA_MUST_THRTL_REGISTER	0x07
106 #define MOXA_MUST_ENUM_REGISTER		0x04
107 #define MOXA_MUST_HWID_REGISTER		0x05
108 #define MOXA_MUST_ECR_REGISTER		0x06
109 #define MOXA_MUST_CSR_REGISTER		0x07
110 
111 #define MOXA_MUST_FCR_GDA_MODE_ENABLE	0x20 /* good data mode enable */
112 #define MOXA_MUST_FCR_GDA_ONLY_ENABLE	0x10 /* only good data put into RxFIFO */
113 
114 #define MOXA_MUST_IER_ECTSI		0x80 /* enable CTS interrupt */
115 #define MOXA_MUST_IER_ERTSI		0x40 /* enable RTS interrupt */
116 #define MOXA_MUST_IER_XINT		0x20 /* enable Xon/Xoff interrupt */
117 #define MOXA_MUST_IER_EGDAI		0x10 /* enable GDA interrupt */
118 
119 #define MOXA_MUST_RECV_ISR		(UART_IER_RDI | MOXA_MUST_IER_EGDAI)
120 
121 /* GDA interrupt pending */
122 #define MOXA_MUST_IIR_GDA		0x1C
123 #define MOXA_MUST_IIR_RDA		0x04
124 #define MOXA_MUST_IIR_RTO		0x0C
125 #define MOXA_MUST_IIR_LSR		0x06
126 
127 /* received Xon/Xoff or specical interrupt pending */
128 #define MOXA_MUST_IIR_XSC		0x10
129 
130 /* RTS/CTS change state interrupt pending */
131 #define MOXA_MUST_IIR_RTSCTS		0x20
132 #define MOXA_MUST_IIR_MASK		0x3E
133 
134 #define MOXA_MUST_MCR_XON_FLAG		0x40
135 #define MOXA_MUST_MCR_XON_ANY		0x80
136 #define MOXA_MUST_MCR_TX_XON		0x08
137 
138 #define MOXA_MUST_EFR_SF_MASK		0x0F /* software flow control on chip mask value */
139 #define MOXA_MUST_EFR_SF_TX1		0x08 /* send Xon1/Xoff1 */
140 #define MOXA_MUST_EFR_SF_TX2		0x04 /* send Xon2/Xoff2 */
141 #define MOXA_MUST_EFR_SF_TX12		0x0C /* send Xon1,Xon2/Xoff1,Xoff2 */
142 #define MOXA_MUST_EFR_SF_TX_NO		0x00 /* don't send Xon/Xoff */
143 #define MOXA_MUST_EFR_SF_TX_MASK	0x0C /* Tx software flow control mask */
144 #define MOXA_MUST_EFR_SF_RX_NO		0x00 /* don't receive Xon/Xoff */
145 #define MOXA_MUST_EFR_SF_RX1		0x02 /* receive Xon1/Xoff1 */
146 #define MOXA_MUST_EFR_SF_RX2		0x01 /* receive Xon2/Xoff2 */
147 #define MOXA_MUST_EFR_SF_RX12		0x03 /* receive Xon1,Xon2/Xoff1,Xoff2 */
148 #define MOXA_MUST_EFR_SF_RX_MASK	0x03 /* Rx software flow control mask */
149 
150 #define	MXSERMAJOR	 174
151 
152 #define MXSER_BOARDS		4	/* Max. boards */
153 #define MXSER_PORTS_PER_BOARD	8	/* Max. ports per board */
154 #define MXSER_PORTS		(MXSER_BOARDS * MXSER_PORTS_PER_BOARD)
155 #define MXSER_ISR_PASS_LIMIT	100
156 
157 #define WAKEUP_CHARS		256
158 
159 #define MXSER_BAUD_BASE		921600
160 #define MXSER_CUSTOM_DIVISOR	(MXSER_BAUD_BASE * 16)
161 
162 #define PCI_DEVICE_ID_POS104UL	0x1044
163 #define PCI_DEVICE_ID_CB108	0x1080
164 #define PCI_DEVICE_ID_CP102UF	0x1023
165 #define PCI_DEVICE_ID_CP112UL	0x1120
166 #define PCI_DEVICE_ID_CB114	0x1142
167 #define PCI_DEVICE_ID_CP114UL	0x1143
168 #define PCI_DEVICE_ID_CB134I	0x1341
169 #define PCI_DEVICE_ID_CP138U	0x1380
170 
171 #define MXSER_NPORTS(ddata)		((ddata) & 0xffU)
172 #define MXSER_HIGHBAUD			0x0100
173 
174 enum mxser_must_hwid {
175 	MOXA_OTHER_UART		= 0x00,
176 	MOXA_MUST_MU150_HWID	= 0x01,
177 	MOXA_MUST_MU860_HWID	= 0x02,
178 };
179 
180 static const struct {
181 	u8 type;
182 	u8 fifo_size;
183 	u8 rx_high_water;
184 	u8 rx_low_water;
185 	speed_t max_baud;
186 } Gpci_uart_info[] = {
187 	{ MOXA_OTHER_UART,	 16, 14,  1, 921600 },
188 	{ MOXA_MUST_MU150_HWID,	 64, 48, 16, 230400 },
189 	{ MOXA_MUST_MU860_HWID, 128, 96, 32, 921600 }
190 };
191 #define UART_INFO_NUM	ARRAY_SIZE(Gpci_uart_info)
192 
193 
194 /* driver_data correspond to the lines in the structure above
195    see also ISA probe function before you change something */
196 static const struct pci_device_id mxser_pcibrds[] = {
197 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_C168),	.driver_data = 8 },
198 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_C104),	.driver_data = 4 },
199 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP132),	.driver_data = 2 },
200 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP114),	.driver_data = 4 },
201 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CT114),	.driver_data = 4 },
202 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP102),	.driver_data = 2 | MXSER_HIGHBAUD },
203 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP104U),	.driver_data = 4 },
204 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP168U),	.driver_data = 8 },
205 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP132U),	.driver_data = 2 },
206 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP134U),	.driver_data = 4 },
207 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP104JU),.driver_data = 4 },
208 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_RC7000),	.driver_data = 8 }, /* RC7000 */
209 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP118U),	.driver_data = 8 },
210 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP102UL),.driver_data = 2 },
211 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP102U),	.driver_data = 2 },
212 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP118EL),.driver_data = 8 },
213 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP168EL),.driver_data = 8 },
214 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP104EL),.driver_data = 4 },
215 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CB108),	.driver_data = 8 },
216 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CB114),	.driver_data = 4 },
217 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CB134I),	.driver_data = 4 },
218 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CP138U),	.driver_data = 8 },
219 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_POS104UL),	.driver_data = 4 },
220 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CP114UL),	.driver_data = 4 },
221 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CP102UF),	.driver_data = 2 },
222 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_CP112UL),	.driver_data = 2 },
223 	{ }
224 };
225 MODULE_DEVICE_TABLE(pci, mxser_pcibrds);
226 
227 static int ttymajor = MXSERMAJOR;
228 
229 /* Variables for insmod */
230 
231 MODULE_AUTHOR("Casper Yang");
232 MODULE_DESCRIPTION("MOXA Smartio/Industio Family Multiport Board Device Driver");
233 module_param(ttymajor, int, 0);
234 MODULE_LICENSE("GPL");
235 
236 struct mxser_board;
237 
238 struct mxser_port {
239 	struct tty_port port;
240 	struct mxser_board *board;
241 
242 	unsigned long ioaddr;
243 	unsigned long opmode_ioaddr;
244 
245 	u8 rx_high_water;
246 	u8 rx_low_water;
247 	int type;		/* UART type */
248 
249 	unsigned char x_char;	/* xon/xoff character */
250 	u8 IER;			/* Interrupt Enable Register */
251 	u8 MCR;			/* Modem control register */
252 
253 	unsigned char ldisc_stop_rx;
254 
255 	struct async_icount icount; /* kernel counters for 4 input interrupts */
256 	unsigned int timeout;
257 
258 	u8 read_status_mask;
259 	u8 ignore_status_mask;
260 	u8 xmit_fifo_size;
261 	unsigned int xmit_head;
262 	unsigned int xmit_tail;
263 	unsigned int xmit_cnt;
264 	int closing;
265 
266 	spinlock_t slock;
267 };
268 
269 struct mxser_board {
270 	unsigned int idx;
271 	unsigned short nports;
272 	int irq;
273 	unsigned long vector;
274 
275 	enum mxser_must_hwid must_hwid;
276 	speed_t max_baud;
277 
278 	struct mxser_port ports[];
279 };
280 
281 static DECLARE_BITMAP(mxser_boards, MXSER_BOARDS);
282 static struct tty_driver *mxvar_sdriver;
283 
284 static u8 __mxser_must_set_EFR(unsigned long baseio, u8 clear, u8 set,
285 		bool restore_LCR)
286 {
287 	u8 oldlcr, efr;
288 
289 	oldlcr = inb(baseio + UART_LCR);
290 	outb(MOXA_MUST_ENTER_ENHANCED, baseio + UART_LCR);
291 
292 	efr = inb(baseio + MOXA_MUST_EFR_REGISTER);
293 	efr &= ~clear;
294 	efr |= set;
295 
296 	outb(efr, baseio + MOXA_MUST_EFR_REGISTER);
297 
298 	if (restore_LCR)
299 		outb(oldlcr, baseio + UART_LCR);
300 
301 	return oldlcr;
302 }
303 
304 static u8 mxser_must_select_bank(unsigned long baseio, u8 bank)
305 {
306 	return __mxser_must_set_EFR(baseio, MOXA_MUST_EFR_BANK_MASK, bank,
307 			false);
308 }
309 
310 static void mxser_set_must_xon1_value(unsigned long baseio, u8 value)
311 {
312 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK0);
313 	outb(value, baseio + MOXA_MUST_XON1_REGISTER);
314 	outb(oldlcr, baseio + UART_LCR);
315 }
316 
317 static void mxser_set_must_xoff1_value(unsigned long baseio, u8 value)
318 {
319 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK0);
320 	outb(value, baseio + MOXA_MUST_XOFF1_REGISTER);
321 	outb(oldlcr, baseio + UART_LCR);
322 }
323 
324 static void mxser_set_must_fifo_value(struct mxser_port *info)
325 {
326 	u8 oldlcr = mxser_must_select_bank(info->ioaddr, MOXA_MUST_EFR_BANK1);
327 	outb(info->rx_high_water, info->ioaddr + MOXA_MUST_RBRTH_REGISTER);
328 	outb(info->rx_high_water, info->ioaddr + MOXA_MUST_RBRTI_REGISTER);
329 	outb(info->rx_low_water, info->ioaddr + MOXA_MUST_RBRTL_REGISTER);
330 	outb(oldlcr, info->ioaddr + UART_LCR);
331 }
332 
333 static void mxser_set_must_enum_value(unsigned long baseio, u8 value)
334 {
335 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK2);
336 	outb(value, baseio + MOXA_MUST_ENUM_REGISTER);
337 	outb(oldlcr, baseio + UART_LCR);
338 }
339 
340 static u8 mxser_get_must_hardware_id(unsigned long baseio)
341 {
342 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK2);
343 	u8 id = inb(baseio + MOXA_MUST_HWID_REGISTER);
344 	outb(oldlcr, baseio + UART_LCR);
345 
346 	return id;
347 }
348 
349 static void mxser_must_set_EFR(unsigned long baseio, u8 clear, u8 set)
350 {
351 	__mxser_must_set_EFR(baseio, clear, set, true);
352 }
353 
354 static void mxser_must_set_enhance_mode(unsigned long baseio, bool enable)
355 {
356 	mxser_must_set_EFR(baseio,
357 			enable ? 0 : MOXA_MUST_EFR_EFRB_ENABLE,
358 			enable ? MOXA_MUST_EFR_EFRB_ENABLE : 0);
359 }
360 
361 static void mxser_must_no_sw_flow_control(unsigned long baseio)
362 {
363 	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_MASK, 0);
364 }
365 
366 static void mxser_must_set_tx_sw_flow_control(unsigned long baseio, bool enable)
367 {
368 	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_TX_MASK,
369 			enable ? MOXA_MUST_EFR_SF_TX1 : 0);
370 }
371 
372 static void mxser_must_set_rx_sw_flow_control(unsigned long baseio, bool enable)
373 {
374 	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_RX_MASK,
375 			enable ? MOXA_MUST_EFR_SF_RX1 : 0);
376 }
377 
378 static enum mxser_must_hwid mxser_must_get_hwid(unsigned long io)
379 {
380 	u8 oldmcr, hwid;
381 	int i;
382 
383 	outb(0, io + UART_LCR);
384 	mxser_must_set_enhance_mode(io, false);
385 	oldmcr = inb(io + UART_MCR);
386 	outb(0, io + UART_MCR);
387 	mxser_set_must_xon1_value(io, 0x11);
388 	if ((hwid = inb(io + UART_MCR)) != 0) {
389 		outb(oldmcr, io + UART_MCR);
390 		return MOXA_OTHER_UART;
391 	}
392 
393 	hwid = mxser_get_must_hardware_id(io);
394 	for (i = 1; i < UART_INFO_NUM; i++) /* 0 = OTHER_UART */
395 		if (hwid == Gpci_uart_info[i].type)
396 			return hwid;
397 
398 	return MOXA_OTHER_UART;
399 }
400 
401 static bool mxser_16550A_or_MUST(struct mxser_port *info)
402 {
403 	return info->type == PORT_16550A || info->board->must_hwid;
404 }
405 
406 static void mxser_process_txrx_fifo(struct mxser_port *info)
407 {
408 	unsigned int i;
409 
410 	if (info->type == PORT_16450 || info->type == PORT_8250) {
411 		info->rx_high_water = 1;
412 		info->rx_low_water = 1;
413 		info->xmit_fifo_size = 1;
414 		return;
415 	}
416 
417 	for (i = 0; i < UART_INFO_NUM; i++)
418 		if (info->board->must_hwid == Gpci_uart_info[i].type) {
419 			info->rx_low_water = Gpci_uart_info[i].rx_low_water;
420 			info->rx_high_water = Gpci_uart_info[i].rx_high_water;
421 			info->xmit_fifo_size = Gpci_uart_info[i].fifo_size;
422 			break;
423 		}
424 }
425 
426 static void __mxser_start_tx(struct mxser_port *info)
427 {
428 	outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
429 	info->IER |= UART_IER_THRI;
430 	outb(info->IER, info->ioaddr + UART_IER);
431 }
432 
433 static void mxser_start_tx(struct mxser_port *info)
434 {
435 	unsigned long flags;
436 
437 	spin_lock_irqsave(&info->slock, flags);
438 	__mxser_start_tx(info);
439 	spin_unlock_irqrestore(&info->slock, flags);
440 }
441 
442 static void __mxser_stop_tx(struct mxser_port *info)
443 {
444 	info->IER &= ~UART_IER_THRI;
445 	outb(info->IER, info->ioaddr + UART_IER);
446 }
447 
448 static int mxser_carrier_raised(struct tty_port *port)
449 {
450 	struct mxser_port *mp = container_of(port, struct mxser_port, port);
451 	return (inb(mp->ioaddr + UART_MSR) & UART_MSR_DCD)?1:0;
452 }
453 
454 static void mxser_dtr_rts(struct tty_port *port, int on)
455 {
456 	struct mxser_port *mp = container_of(port, struct mxser_port, port);
457 	unsigned long flags;
458 	u8 mcr;
459 
460 	spin_lock_irqsave(&mp->slock, flags);
461 	mcr = inb(mp->ioaddr + UART_MCR);
462 	if (on)
463 		mcr |= UART_MCR_DTR | UART_MCR_RTS;
464 	else
465 		mcr &= ~(UART_MCR_DTR | UART_MCR_RTS);
466 	outb(mcr, mp->ioaddr + UART_MCR);
467 	spin_unlock_irqrestore(&mp->slock, flags);
468 }
469 
470 static int mxser_set_baud(struct tty_struct *tty, speed_t newspd)
471 {
472 	struct mxser_port *info = tty->driver_data;
473 	unsigned int quot = 0, baud;
474 	unsigned char cval;
475 	u64 timeout;
476 
477 	if (newspd > info->board->max_baud)
478 		return -1;
479 
480 	if (newspd == 134) {
481 		quot = 2 * MXSER_BAUD_BASE / 269;
482 		tty_encode_baud_rate(tty, 134, 134);
483 	} else if (newspd) {
484 		quot = MXSER_BAUD_BASE / newspd;
485 		if (quot == 0)
486 			quot = 1;
487 		baud = MXSER_BAUD_BASE / quot;
488 		tty_encode_baud_rate(tty, baud, baud);
489 	} else {
490 		quot = 0;
491 	}
492 
493 	/*
494 	 * worst case (128 * 1000 * 10 * 18432) needs 35 bits, so divide in the
495 	 * u64 domain
496 	 */
497 	timeout = (u64)info->xmit_fifo_size * HZ * 10 * quot;
498 	do_div(timeout, MXSER_BAUD_BASE);
499 	info->timeout = timeout + HZ / 50; /* Add .02 seconds of slop */
500 
501 	if (quot) {
502 		info->MCR |= UART_MCR_DTR;
503 		outb(info->MCR, info->ioaddr + UART_MCR);
504 	} else {
505 		info->MCR &= ~UART_MCR_DTR;
506 		outb(info->MCR, info->ioaddr + UART_MCR);
507 		return 0;
508 	}
509 
510 	cval = inb(info->ioaddr + UART_LCR);
511 
512 	outb(cval | UART_LCR_DLAB, info->ioaddr + UART_LCR);	/* set DLAB */
513 
514 	outb(quot & 0xff, info->ioaddr + UART_DLL);	/* LS of divisor */
515 	outb(quot >> 8, info->ioaddr + UART_DLM);	/* MS of divisor */
516 	outb(cval, info->ioaddr + UART_LCR);	/* reset DLAB */
517 
518 #ifdef BOTHER
519 	if (C_BAUD(tty) == BOTHER) {
520 		quot = MXSER_BAUD_BASE % newspd;
521 		quot *= 8;
522 		if (quot % newspd > newspd / 2) {
523 			quot /= newspd;
524 			quot++;
525 		} else
526 			quot /= newspd;
527 
528 		mxser_set_must_enum_value(info->ioaddr, quot);
529 	} else
530 #endif
531 		mxser_set_must_enum_value(info->ioaddr, 0);
532 
533 	return 0;
534 }
535 
536 static void mxser_handle_cts(struct tty_struct *tty, struct mxser_port *info,
537 		u8 msr)
538 {
539 	bool cts = msr & UART_MSR_CTS;
540 
541 	if (tty->hw_stopped) {
542 		if (cts) {
543 			tty->hw_stopped = 0;
544 
545 			if (!mxser_16550A_or_MUST(info))
546 				__mxser_start_tx(info);
547 			tty_wakeup(tty);
548 		}
549 		return;
550 	} else if (cts)
551 		return;
552 
553 	tty->hw_stopped = 1;
554 	if (!mxser_16550A_or_MUST(info))
555 		__mxser_stop_tx(info);
556 }
557 
558 /*
559  * This routine is called to set the UART divisor registers to match
560  * the specified baud rate for a serial port.
561  */
562 static void mxser_change_speed(struct tty_struct *tty)
563 {
564 	struct mxser_port *info = tty->driver_data;
565 	unsigned cflag, cval, fcr;
566 
567 	cflag = tty->termios.c_cflag;
568 
569 	mxser_set_baud(tty, tty_get_baud_rate(tty));
570 
571 	/* byte size and parity */
572 	switch (cflag & CSIZE) {
573 	default:
574 	case CS5:
575 		cval = UART_LCR_WLEN5;
576 		break;
577 	case CS6:
578 		cval = UART_LCR_WLEN6;
579 		break;
580 	case CS7:
581 		cval = UART_LCR_WLEN7;
582 		break;
583 	case CS8:
584 		cval = UART_LCR_WLEN8;
585 		break;
586 	}
587 
588 	if (cflag & CSTOPB)
589 		cval |= UART_LCR_STOP;
590 	if (cflag & PARENB)
591 		cval |= UART_LCR_PARITY;
592 	if (!(cflag & PARODD))
593 		cval |= UART_LCR_EPAR;
594 	if (cflag & CMSPAR)
595 		cval |= UART_LCR_SPAR;
596 
597 	if ((info->type == PORT_8250) || (info->type == PORT_16450)) {
598 		if (info->board->must_hwid) {
599 			fcr = UART_FCR_ENABLE_FIFO;
600 			fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
601 			mxser_set_must_fifo_value(info);
602 		} else
603 			fcr = 0;
604 	} else {
605 		fcr = UART_FCR_ENABLE_FIFO;
606 		if (info->board->must_hwid) {
607 			fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
608 			mxser_set_must_fifo_value(info);
609 		} else {
610 			switch (info->rx_high_water) {
611 			case 1:
612 				fcr |= UART_FCR_TRIGGER_1;
613 				break;
614 			case 4:
615 				fcr |= UART_FCR_TRIGGER_4;
616 				break;
617 			case 8:
618 				fcr |= UART_FCR_TRIGGER_8;
619 				break;
620 			default:
621 				fcr |= UART_FCR_TRIGGER_14;
622 				break;
623 			}
624 		}
625 	}
626 
627 	/* CTS flow control flag and modem status interrupts */
628 	info->IER &= ~UART_IER_MSI;
629 	info->MCR &= ~UART_MCR_AFE;
630 	tty_port_set_cts_flow(&info->port, cflag & CRTSCTS);
631 	if (cflag & CRTSCTS) {
632 		info->IER |= UART_IER_MSI;
633 		if (mxser_16550A_or_MUST(info)) {
634 			info->MCR |= UART_MCR_AFE;
635 		} else {
636 			mxser_handle_cts(tty, info,
637 					inb(info->ioaddr + UART_MSR));
638 		}
639 	}
640 	outb(info->MCR, info->ioaddr + UART_MCR);
641 	tty_port_set_check_carrier(&info->port, ~cflag & CLOCAL);
642 	if (~cflag & CLOCAL)
643 		info->IER |= UART_IER_MSI;
644 	outb(info->IER, info->ioaddr + UART_IER);
645 
646 	/*
647 	 * Set up parity check flag
648 	 */
649 	info->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
650 	if (I_INPCK(tty))
651 		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
652 	if (I_BRKINT(tty) || I_PARMRK(tty))
653 		info->read_status_mask |= UART_LSR_BI;
654 
655 	info->ignore_status_mask = 0;
656 
657 	if (I_IGNBRK(tty)) {
658 		info->ignore_status_mask |= UART_LSR_BI;
659 		info->read_status_mask |= UART_LSR_BI;
660 		/*
661 		 * If we're ignore parity and break indicators, ignore
662 		 * overruns too.  (For real raw support).
663 		 */
664 		if (I_IGNPAR(tty)) {
665 			info->ignore_status_mask |=
666 						UART_LSR_OE |
667 						UART_LSR_PE |
668 						UART_LSR_FE;
669 			info->read_status_mask |=
670 						UART_LSR_OE |
671 						UART_LSR_PE |
672 						UART_LSR_FE;
673 		}
674 	}
675 	if (info->board->must_hwid) {
676 		mxser_set_must_xon1_value(info->ioaddr, START_CHAR(tty));
677 		mxser_set_must_xoff1_value(info->ioaddr, STOP_CHAR(tty));
678 		mxser_must_set_rx_sw_flow_control(info->ioaddr, I_IXON(tty));
679 		mxser_must_set_tx_sw_flow_control(info->ioaddr, I_IXOFF(tty));
680 	}
681 
682 
683 	outb(fcr, info->ioaddr + UART_FCR);	/* set fcr */
684 	outb(cval, info->ioaddr + UART_LCR);
685 }
686 
687 static void mxser_check_modem_status(struct tty_struct *tty,
688 				struct mxser_port *port, int status)
689 {
690 	/* update input line counters */
691 	if (status & UART_MSR_TERI)
692 		port->icount.rng++;
693 	if (status & UART_MSR_DDSR)
694 		port->icount.dsr++;
695 	if (status & UART_MSR_DDCD)
696 		port->icount.dcd++;
697 	if (status & UART_MSR_DCTS)
698 		port->icount.cts++;
699 	wake_up_interruptible(&port->port.delta_msr_wait);
700 
701 	if (tty_port_check_carrier(&port->port) && (status & UART_MSR_DDCD)) {
702 		if (status & UART_MSR_DCD)
703 			wake_up_interruptible(&port->port.open_wait);
704 	}
705 
706 	if (tty_port_cts_enabled(&port->port))
707 		mxser_handle_cts(tty, port, status);
708 }
709 
710 static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
711 {
712 	struct mxser_port *info = container_of(port, struct mxser_port, port);
713 	unsigned long page;
714 	unsigned long flags;
715 
716 	page = __get_free_page(GFP_KERNEL);
717 	if (!page)
718 		return -ENOMEM;
719 
720 	spin_lock_irqsave(&info->slock, flags);
721 
722 	if (!info->type) {
723 		set_bit(TTY_IO_ERROR, &tty->flags);
724 		free_page(page);
725 		spin_unlock_irqrestore(&info->slock, flags);
726 		return 0;
727 	}
728 	info->port.xmit_buf = (unsigned char *) page;
729 
730 	/*
731 	 * Clear the FIFO buffers and disable them
732 	 * (they will be reenabled in mxser_change_speed())
733 	 */
734 	if (info->board->must_hwid)
735 		outb((UART_FCR_CLEAR_RCVR |
736 			UART_FCR_CLEAR_XMIT |
737 			MOXA_MUST_FCR_GDA_MODE_ENABLE), info->ioaddr + UART_FCR);
738 	else
739 		outb((UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT),
740 			info->ioaddr + UART_FCR);
741 
742 	/*
743 	 * At this point there's no way the LSR could still be 0xFF;
744 	 * if it is, then bail out, because there's likely no UART
745 	 * here.
746 	 */
747 	if (inb(info->ioaddr + UART_LSR) == 0xff) {
748 		spin_unlock_irqrestore(&info->slock, flags);
749 		if (capable(CAP_SYS_ADMIN)) {
750 			set_bit(TTY_IO_ERROR, &tty->flags);
751 			return 0;
752 		} else
753 			return -ENODEV;
754 	}
755 
756 	/*
757 	 * Clear the interrupt registers.
758 	 */
759 	(void) inb(info->ioaddr + UART_LSR);
760 	(void) inb(info->ioaddr + UART_RX);
761 	(void) inb(info->ioaddr + UART_IIR);
762 	(void) inb(info->ioaddr + UART_MSR);
763 
764 	/*
765 	 * Now, initialize the UART
766 	 */
767 	outb(UART_LCR_WLEN8, info->ioaddr + UART_LCR);	/* reset DLAB */
768 	info->MCR = UART_MCR_DTR | UART_MCR_RTS;
769 	outb(info->MCR, info->ioaddr + UART_MCR);
770 
771 	/*
772 	 * Finally, enable interrupts
773 	 */
774 	info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
775 
776 	if (info->board->must_hwid)
777 		info->IER |= MOXA_MUST_IER_EGDAI;
778 	outb(info->IER, info->ioaddr + UART_IER);	/* enable interrupts */
779 
780 	/*
781 	 * And clear the interrupt registers again for luck.
782 	 */
783 	(void) inb(info->ioaddr + UART_LSR);
784 	(void) inb(info->ioaddr + UART_RX);
785 	(void) inb(info->ioaddr + UART_IIR);
786 	(void) inb(info->ioaddr + UART_MSR);
787 
788 	clear_bit(TTY_IO_ERROR, &tty->flags);
789 	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
790 
791 	/*
792 	 * and set the speed of the serial port
793 	 */
794 	mxser_change_speed(tty);
795 	spin_unlock_irqrestore(&info->slock, flags);
796 
797 	return 0;
798 }
799 
800 /*
801  * This routine will shutdown a serial port
802  */
803 static void mxser_shutdown_port(struct tty_port *port)
804 {
805 	struct mxser_port *info = container_of(port, struct mxser_port, port);
806 	unsigned long flags;
807 
808 	spin_lock_irqsave(&info->slock, flags);
809 
810 	/*
811 	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
812 	 * here so the queue might never be waken up
813 	 */
814 	wake_up_interruptible(&info->port.delta_msr_wait);
815 
816 	/*
817 	 * Free the xmit buffer, if necessary
818 	 */
819 	if (info->port.xmit_buf) {
820 		free_page((unsigned long) info->port.xmit_buf);
821 		info->port.xmit_buf = NULL;
822 	}
823 
824 	info->IER = 0;
825 	outb(0x00, info->ioaddr + UART_IER);
826 
827 	/* clear Rx/Tx FIFO's */
828 	if (info->board->must_hwid)
829 		outb(UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT |
830 				MOXA_MUST_FCR_GDA_MODE_ENABLE,
831 				info->ioaddr + UART_FCR);
832 	else
833 		outb(UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
834 			info->ioaddr + UART_FCR);
835 
836 	/* read data port to reset things */
837 	(void) inb(info->ioaddr + UART_RX);
838 
839 
840 	if (info->board->must_hwid)
841 		mxser_must_no_sw_flow_control(info->ioaddr);
842 
843 	spin_unlock_irqrestore(&info->slock, flags);
844 }
845 
846 /*
847  * This routine is called whenever a serial port is opened.  It
848  * enables interrupts for a serial port, linking in its async structure into
849  * the IRQ chain.   It also performs the serial-specific
850  * initialization for the tty structure.
851  */
852 static int mxser_open(struct tty_struct *tty, struct file *filp)
853 {
854 	struct tty_port *tport = tty->port;
855 	struct mxser_port *port = container_of(tport, struct mxser_port, port);
856 
857 	tty->driver_data = port;
858 
859 	return tty_port_open(tport, tty, filp);
860 }
861 
862 static void mxser_flush_buffer(struct tty_struct *tty)
863 {
864 	struct mxser_port *info = tty->driver_data;
865 	char fcr;
866 	unsigned long flags;
867 
868 
869 	spin_lock_irqsave(&info->slock, flags);
870 	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
871 
872 	fcr = inb(info->ioaddr + UART_FCR);
873 	outb((fcr | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT),
874 		info->ioaddr + UART_FCR);
875 	outb(fcr, info->ioaddr + UART_FCR);
876 
877 	spin_unlock_irqrestore(&info->slock, flags);
878 
879 	tty_wakeup(tty);
880 }
881 
882 
883 static void mxser_close_port(struct tty_port *port)
884 {
885 	struct mxser_port *info = container_of(port, struct mxser_port, port);
886 	unsigned long timeout;
887 	/*
888 	 * At this point we stop accepting input.  To do this, we
889 	 * disable the receive line status interrupts, and tell the
890 	 * interrupt driver to stop checking the data ready bit in the
891 	 * line status register.
892 	 */
893 	info->IER &= ~UART_IER_RLSI;
894 	if (info->board->must_hwid)
895 		info->IER &= ~MOXA_MUST_RECV_ISR;
896 
897 	outb(info->IER, info->ioaddr + UART_IER);
898 	/*
899 	 * Before we drop DTR, make sure the UART transmitter
900 	 * has completely drained; this is especially
901 	 * important if there is a transmit FIFO!
902 	 */
903 	timeout = jiffies + HZ;
904 	while (!(inb(info->ioaddr + UART_LSR) & UART_LSR_TEMT)) {
905 		schedule_timeout_interruptible(5);
906 		if (time_after(jiffies, timeout))
907 			break;
908 	}
909 }
910 
911 /*
912  * This routine is called when the serial port gets closed.  First, we
913  * wait for the last remaining data to be sent.  Then, we unlink its
914  * async structure from the interrupt chain if necessary, and we free
915  * that IRQ if nothing is left in the chain.
916  */
917 static void mxser_close(struct tty_struct *tty, struct file *filp)
918 {
919 	struct mxser_port *info = tty->driver_data;
920 	struct tty_port *port = &info->port;
921 
922 	if (info == NULL)
923 		return;
924 	if (tty_port_close_start(port, tty, filp) == 0)
925 		return;
926 	info->closing = 1;
927 	mutex_lock(&port->mutex);
928 	mxser_close_port(port);
929 	mxser_flush_buffer(tty);
930 	if (tty_port_initialized(port) && C_HUPCL(tty))
931 		tty_port_lower_dtr_rts(port);
932 	mxser_shutdown_port(port);
933 	tty_port_set_initialized(port, 0);
934 	mutex_unlock(&port->mutex);
935 	info->closing = 0;
936 	/* Right now the tty_port set is done outside of the close_end helper
937 	   as we don't yet have everyone using refcounts */
938 	tty_port_close_end(port, tty);
939 	tty_port_tty_set(port, NULL);
940 }
941 
942 static int mxser_write(struct tty_struct *tty, const unsigned char *buf, int count)
943 {
944 	int c, total = 0;
945 	struct mxser_port *info = tty->driver_data;
946 	unsigned long flags;
947 
948 	if (!info->port.xmit_buf)
949 		return 0;
950 
951 	while (1) {
952 		c = min_t(int, count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
953 					  SERIAL_XMIT_SIZE - info->xmit_head));
954 		if (c <= 0)
955 			break;
956 
957 		memcpy(info->port.xmit_buf + info->xmit_head, buf, c);
958 		spin_lock_irqsave(&info->slock, flags);
959 		info->xmit_head = (info->xmit_head + c) &
960 				  (SERIAL_XMIT_SIZE - 1);
961 		info->xmit_cnt += c;
962 		spin_unlock_irqrestore(&info->slock, flags);
963 
964 		buf += c;
965 		count -= c;
966 		total += c;
967 	}
968 
969 	if (info->xmit_cnt && !tty->flow.stopped)
970 		if (!tty->hw_stopped || mxser_16550A_or_MUST(info))
971 			mxser_start_tx(info);
972 
973 	return total;
974 }
975 
976 static int mxser_put_char(struct tty_struct *tty, unsigned char ch)
977 {
978 	struct mxser_port *info = tty->driver_data;
979 	unsigned long flags;
980 
981 	if (!info->port.xmit_buf)
982 		return 0;
983 
984 	if (info->xmit_cnt >= SERIAL_XMIT_SIZE - 1)
985 		return 0;
986 
987 	spin_lock_irqsave(&info->slock, flags);
988 	info->port.xmit_buf[info->xmit_head++] = ch;
989 	info->xmit_head &= SERIAL_XMIT_SIZE - 1;
990 	info->xmit_cnt++;
991 	spin_unlock_irqrestore(&info->slock, flags);
992 
993 	return 1;
994 }
995 
996 
997 static void mxser_flush_chars(struct tty_struct *tty)
998 {
999 	struct mxser_port *info = tty->driver_data;
1000 
1001 	if (!info->xmit_cnt || tty->flow.stopped || !info->port.xmit_buf ||
1002 			(tty->hw_stopped && !mxser_16550A_or_MUST(info)))
1003 		return;
1004 
1005 	mxser_start_tx(info);
1006 }
1007 
1008 static unsigned int mxser_write_room(struct tty_struct *tty)
1009 {
1010 	struct mxser_port *info = tty->driver_data;
1011 	int ret;
1012 
1013 	ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
1014 	return ret < 0 ? 0 : ret;
1015 }
1016 
1017 static unsigned int mxser_chars_in_buffer(struct tty_struct *tty)
1018 {
1019 	struct mxser_port *info = tty->driver_data;
1020 	return info->xmit_cnt;
1021 }
1022 
1023 /*
1024  * ------------------------------------------------------------
1025  * friends of mxser_ioctl()
1026  * ------------------------------------------------------------
1027  */
1028 static int mxser_get_serial_info(struct tty_struct *tty,
1029 		struct serial_struct *ss)
1030 {
1031 	struct mxser_port *info = tty->driver_data;
1032 	struct tty_port *port = &info->port;
1033 	unsigned int closing_wait, close_delay;
1034 
1035 	mutex_lock(&port->mutex);
1036 
1037 	close_delay = jiffies_to_msecs(info->port.close_delay) / 10;
1038 	closing_wait = info->port.closing_wait;
1039 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
1040 		closing_wait = jiffies_to_msecs(closing_wait) / 10;
1041 
1042 	ss->type = info->type,
1043 	ss->line = tty->index,
1044 	ss->port = info->ioaddr,
1045 	ss->irq = info->board->irq,
1046 	ss->flags = info->port.flags,
1047 	ss->baud_base = MXSER_BAUD_BASE,
1048 	ss->close_delay = close_delay;
1049 	ss->closing_wait = closing_wait;
1050 	ss->custom_divisor = MXSER_CUSTOM_DIVISOR,
1051 	mutex_unlock(&port->mutex);
1052 	return 0;
1053 }
1054 
1055 static int mxser_set_serial_info(struct tty_struct *tty,
1056 		struct serial_struct *ss)
1057 {
1058 	struct mxser_port *info = tty->driver_data;
1059 	struct tty_port *port = &info->port;
1060 	speed_t baud;
1061 	unsigned long sl_flags;
1062 	unsigned int old_speed, close_delay, closing_wait;
1063 	int retval = 0;
1064 
1065 	if (tty_io_error(tty))
1066 		return -EIO;
1067 
1068 	mutex_lock(&port->mutex);
1069 
1070 	if (ss->irq != info->board->irq ||
1071 			ss->port != info->ioaddr) {
1072 		mutex_unlock(&port->mutex);
1073 		return -EINVAL;
1074 	}
1075 
1076 	old_speed = port->flags & ASYNC_SPD_MASK;
1077 
1078 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
1079 	closing_wait = ss->closing_wait;
1080 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
1081 		closing_wait = msecs_to_jiffies(closing_wait * 10);
1082 
1083 	if (!capable(CAP_SYS_ADMIN)) {
1084 		if ((ss->baud_base != MXSER_BAUD_BASE) ||
1085 				(close_delay != port->close_delay) ||
1086 				(closing_wait != port->closing_wait) ||
1087 				((ss->flags & ~ASYNC_USR_MASK) != (port->flags & ~ASYNC_USR_MASK))) {
1088 			mutex_unlock(&port->mutex);
1089 			return -EPERM;
1090 		}
1091 		port->flags = (port->flags & ~ASYNC_USR_MASK) |
1092 				(ss->flags & ASYNC_USR_MASK);
1093 	} else {
1094 		/*
1095 		 * OK, past this point, all the error checking has been done.
1096 		 * At this point, we start making changes.....
1097 		 */
1098 		port->flags = ((port->flags & ~ASYNC_FLAGS) |
1099 				(ss->flags & ASYNC_FLAGS));
1100 		port->close_delay = close_delay;
1101 		port->closing_wait = closing_wait;
1102 		if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST &&
1103 				(ss->baud_base != MXSER_BAUD_BASE ||
1104 				ss->custom_divisor !=
1105 				MXSER_CUSTOM_DIVISOR)) {
1106 			if (ss->custom_divisor == 0) {
1107 				mutex_unlock(&port->mutex);
1108 				return -EINVAL;
1109 			}
1110 			baud = ss->baud_base / ss->custom_divisor;
1111 			tty_encode_baud_rate(tty, baud, baud);
1112 		}
1113 
1114 		info->type = ss->type;
1115 
1116 		mxser_process_txrx_fifo(info);
1117 	}
1118 
1119 	if (tty_port_initialized(port)) {
1120 		if (old_speed != (port->flags & ASYNC_SPD_MASK)) {
1121 			spin_lock_irqsave(&info->slock, sl_flags);
1122 			mxser_change_speed(tty);
1123 			spin_unlock_irqrestore(&info->slock, sl_flags);
1124 		}
1125 	} else {
1126 		retval = mxser_activate(port, tty);
1127 		if (retval == 0)
1128 			tty_port_set_initialized(port, 1);
1129 	}
1130 	mutex_unlock(&port->mutex);
1131 	return retval;
1132 }
1133 
1134 /*
1135  * mxser_get_lsr_info - get line status register info
1136  *
1137  * Purpose: Let user call ioctl() to get info when the UART physically
1138  *	    is emptied.  On bus types like RS485, the transmitter must
1139  *	    release the bus after transmitting. This must be done when
1140  *	    the transmit shift register is empty, not be done when the
1141  *	    transmit holding register is empty.  This functionality
1142  *	    allows an RS485 driver to be written in user space.
1143  */
1144 static int mxser_get_lsr_info(struct mxser_port *info,
1145 		unsigned int __user *value)
1146 {
1147 	unsigned char status;
1148 	unsigned int result;
1149 	unsigned long flags;
1150 
1151 	spin_lock_irqsave(&info->slock, flags);
1152 	status = inb(info->ioaddr + UART_LSR);
1153 	spin_unlock_irqrestore(&info->slock, flags);
1154 	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
1155 	return put_user(result, value);
1156 }
1157 
1158 static int mxser_tiocmget(struct tty_struct *tty)
1159 {
1160 	struct mxser_port *info = tty->driver_data;
1161 	unsigned char control, status;
1162 	unsigned long flags;
1163 
1164 	if (tty_io_error(tty))
1165 		return -EIO;
1166 
1167 	spin_lock_irqsave(&info->slock, flags);
1168 	control = info->MCR;
1169 	status = inb(info->ioaddr + UART_MSR);
1170 	if (status & UART_MSR_ANY_DELTA)
1171 		mxser_check_modem_status(tty, info, status);
1172 	spin_unlock_irqrestore(&info->slock, flags);
1173 
1174 	return ((control & UART_MCR_RTS) ? TIOCM_RTS : 0) |
1175 		    ((control & UART_MCR_DTR) ? TIOCM_DTR : 0) |
1176 		    ((status & UART_MSR_DCD) ? TIOCM_CAR : 0) |
1177 		    ((status & UART_MSR_RI) ? TIOCM_RNG : 0) |
1178 		    ((status & UART_MSR_DSR) ? TIOCM_DSR : 0) |
1179 		    ((status & UART_MSR_CTS) ? TIOCM_CTS : 0);
1180 }
1181 
1182 static int mxser_tiocmset(struct tty_struct *tty,
1183 		unsigned int set, unsigned int clear)
1184 {
1185 	struct mxser_port *info = tty->driver_data;
1186 	unsigned long flags;
1187 
1188 	if (tty_io_error(tty))
1189 		return -EIO;
1190 
1191 	spin_lock_irqsave(&info->slock, flags);
1192 
1193 	if (set & TIOCM_RTS)
1194 		info->MCR |= UART_MCR_RTS;
1195 	if (set & TIOCM_DTR)
1196 		info->MCR |= UART_MCR_DTR;
1197 
1198 	if (clear & TIOCM_RTS)
1199 		info->MCR &= ~UART_MCR_RTS;
1200 	if (clear & TIOCM_DTR)
1201 		info->MCR &= ~UART_MCR_DTR;
1202 
1203 	outb(info->MCR, info->ioaddr + UART_MCR);
1204 	spin_unlock_irqrestore(&info->slock, flags);
1205 	return 0;
1206 }
1207 
1208 static int mxser_cflags_changed(struct mxser_port *info, unsigned long arg,
1209 		struct async_icount *cprev)
1210 {
1211 	struct async_icount cnow;
1212 	unsigned long flags;
1213 	int ret;
1214 
1215 	spin_lock_irqsave(&info->slock, flags);
1216 	cnow = info->icount;	/* atomic copy */
1217 	spin_unlock_irqrestore(&info->slock, flags);
1218 
1219 	ret =	((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
1220 		((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
1221 		((arg & TIOCM_CD)  && (cnow.dcd != cprev->dcd)) ||
1222 		((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
1223 
1224 	*cprev = cnow;
1225 
1226 	return ret;
1227 }
1228 
1229 /* We should likely switch to TIOCGRS485/TIOCSRS485. */
1230 static int mxser_ioctl_op_mode(struct mxser_port *port, int index, bool set,
1231 		int __user *u_opmode)
1232 {
1233 	int opmode, p = index % 4;
1234 	int shiftbit = p * 2;
1235 	u8 val;
1236 
1237 	if (port->board->must_hwid != MOXA_MUST_MU860_HWID)
1238 		return -EFAULT;
1239 
1240 	if (set) {
1241 		if (get_user(opmode, u_opmode))
1242 			return -EFAULT;
1243 
1244 		if (opmode & ~OP_MODE_MASK)
1245 			return -EINVAL;
1246 
1247 		spin_lock_irq(&port->slock);
1248 		val = inb(port->opmode_ioaddr);
1249 		val &= ~(OP_MODE_MASK << shiftbit);
1250 		val |= (opmode << shiftbit);
1251 		outb(val, port->opmode_ioaddr);
1252 		spin_unlock_irq(&port->slock);
1253 
1254 		return 0;
1255 	}
1256 
1257 	spin_lock_irq(&port->slock);
1258 	opmode = inb(port->opmode_ioaddr) >> shiftbit;
1259 	spin_unlock_irq(&port->slock);
1260 
1261 	return put_user(opmode & OP_MODE_MASK, u_opmode);
1262 }
1263 
1264 static int mxser_ioctl(struct tty_struct *tty,
1265 		unsigned int cmd, unsigned long arg)
1266 {
1267 	struct mxser_port *info = tty->driver_data;
1268 	struct async_icount cnow;
1269 	unsigned long flags;
1270 	void __user *argp = (void __user *)arg;
1271 
1272 	if (cmd == MOXA_SET_OP_MODE || cmd == MOXA_GET_OP_MODE)
1273 		return mxser_ioctl_op_mode(info, tty->index,
1274 				cmd == MOXA_SET_OP_MODE, argp);
1275 
1276 	if (cmd != TIOCMIWAIT && tty_io_error(tty))
1277 		return -EIO;
1278 
1279 	switch (cmd) {
1280 	case TIOCSERGETLSR:	/* Get line status register */
1281 		return  mxser_get_lsr_info(info, argp);
1282 		/*
1283 		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1284 		 * - mask passed in arg for lines of interest
1285 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1286 		 * Caller should use TIOCGICOUNT to see which one it was
1287 		 */
1288 	case TIOCMIWAIT:
1289 		spin_lock_irqsave(&info->slock, flags);
1290 		cnow = info->icount;	/* note the counters on entry */
1291 		spin_unlock_irqrestore(&info->slock, flags);
1292 
1293 		return wait_event_interruptible(info->port.delta_msr_wait,
1294 				mxser_cflags_changed(info, arg, &cnow));
1295 	default:
1296 		return -ENOIOCTLCMD;
1297 	}
1298 	return 0;
1299 }
1300 
1301 	/*
1302 	 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1303 	 * Return: write counters to the user passed counter struct
1304 	 * NB: both 1->0 and 0->1 transitions are counted except for
1305 	 *     RI where only 0->1 is counted.
1306 	 */
1307 
1308 static int mxser_get_icount(struct tty_struct *tty,
1309 		struct serial_icounter_struct *icount)
1310 
1311 {
1312 	struct mxser_port *info = tty->driver_data;
1313 	struct async_icount cnow;
1314 	unsigned long flags;
1315 
1316 	spin_lock_irqsave(&info->slock, flags);
1317 	cnow = info->icount;
1318 	spin_unlock_irqrestore(&info->slock, flags);
1319 
1320 	icount->frame = cnow.frame;
1321 	icount->brk = cnow.brk;
1322 	icount->overrun = cnow.overrun;
1323 	icount->buf_overrun = cnow.buf_overrun;
1324 	icount->parity = cnow.parity;
1325 	icount->rx = cnow.rx;
1326 	icount->tx = cnow.tx;
1327 	icount->cts = cnow.cts;
1328 	icount->dsr = cnow.dsr;
1329 	icount->rng = cnow.rng;
1330 	icount->dcd = cnow.dcd;
1331 	return 0;
1332 }
1333 
1334 static void mxser_stoprx(struct tty_struct *tty)
1335 {
1336 	struct mxser_port *info = tty->driver_data;
1337 
1338 	info->ldisc_stop_rx = 1;
1339 	if (I_IXOFF(tty)) {
1340 		if (info->board->must_hwid) {
1341 			info->IER &= ~MOXA_MUST_RECV_ISR;
1342 			outb(info->IER, info->ioaddr + UART_IER);
1343 		} else {
1344 			info->x_char = STOP_CHAR(tty);
1345 			outb(0, info->ioaddr + UART_IER);
1346 			info->IER |= UART_IER_THRI;
1347 			outb(info->IER, info->ioaddr + UART_IER);
1348 		}
1349 	}
1350 
1351 	if (C_CRTSCTS(tty)) {
1352 		info->MCR &= ~UART_MCR_RTS;
1353 		outb(info->MCR, info->ioaddr + UART_MCR);
1354 	}
1355 }
1356 
1357 /*
1358  * This routine is called by the upper-layer tty layer to signal that
1359  * incoming characters should be throttled.
1360  */
1361 static void mxser_throttle(struct tty_struct *tty)
1362 {
1363 	mxser_stoprx(tty);
1364 }
1365 
1366 static void mxser_unthrottle(struct tty_struct *tty)
1367 {
1368 	struct mxser_port *info = tty->driver_data;
1369 
1370 	/* startrx */
1371 	info->ldisc_stop_rx = 0;
1372 	if (I_IXOFF(tty)) {
1373 		if (info->x_char)
1374 			info->x_char = 0;
1375 		else {
1376 			if (info->board->must_hwid) {
1377 				info->IER |= MOXA_MUST_RECV_ISR;
1378 				outb(info->IER, info->ioaddr + UART_IER);
1379 			} else {
1380 				info->x_char = START_CHAR(tty);
1381 				outb(0, info->ioaddr + UART_IER);
1382 				info->IER |= UART_IER_THRI;
1383 				outb(info->IER, info->ioaddr + UART_IER);
1384 			}
1385 		}
1386 	}
1387 
1388 	if (C_CRTSCTS(tty)) {
1389 		info->MCR |= UART_MCR_RTS;
1390 		outb(info->MCR, info->ioaddr + UART_MCR);
1391 	}
1392 }
1393 
1394 /*
1395  * mxser_stop() and mxser_start()
1396  *
1397  * This routines are called before setting or resetting tty->flow.stopped.
1398  * They enable or disable transmitter interrupts, as necessary.
1399  */
1400 static void mxser_stop(struct tty_struct *tty)
1401 {
1402 	struct mxser_port *info = tty->driver_data;
1403 	unsigned long flags;
1404 
1405 	spin_lock_irqsave(&info->slock, flags);
1406 	if (info->IER & UART_IER_THRI)
1407 		__mxser_stop_tx(info);
1408 	spin_unlock_irqrestore(&info->slock, flags);
1409 }
1410 
1411 static void mxser_start(struct tty_struct *tty)
1412 {
1413 	struct mxser_port *info = tty->driver_data;
1414 	unsigned long flags;
1415 
1416 	spin_lock_irqsave(&info->slock, flags);
1417 	if (info->xmit_cnt && info->port.xmit_buf)
1418 		__mxser_start_tx(info);
1419 	spin_unlock_irqrestore(&info->slock, flags);
1420 }
1421 
1422 static void mxser_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1423 {
1424 	struct mxser_port *info = tty->driver_data;
1425 	unsigned long flags;
1426 
1427 	spin_lock_irqsave(&info->slock, flags);
1428 	mxser_change_speed(tty);
1429 	spin_unlock_irqrestore(&info->slock, flags);
1430 
1431 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
1432 		tty->hw_stopped = 0;
1433 		mxser_start(tty);
1434 	}
1435 
1436 	/* Handle sw stopped */
1437 	if ((old_termios->c_iflag & IXON) && !I_IXON(tty)) {
1438 		tty->flow.stopped = 0;
1439 
1440 		if (info->board->must_hwid) {
1441 			spin_lock_irqsave(&info->slock, flags);
1442 			mxser_must_set_rx_sw_flow_control(info->ioaddr, false);
1443 			spin_unlock_irqrestore(&info->slock, flags);
1444 		}
1445 
1446 		mxser_start(tty);
1447 	}
1448 }
1449 
1450 /*
1451  * mxser_wait_until_sent() --- wait until the transmitter is empty
1452  */
1453 static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
1454 {
1455 	struct mxser_port *info = tty->driver_data;
1456 	unsigned long orig_jiffies, char_time;
1457 	unsigned long flags;
1458 	int lsr;
1459 
1460 	if (info->type == PORT_UNKNOWN)
1461 		return;
1462 
1463 	if (info->xmit_fifo_size == 0)
1464 		return;		/* Just in case.... */
1465 
1466 	orig_jiffies = jiffies;
1467 	/*
1468 	 * Set the check interval to be 1/5 of the estimated time to
1469 	 * send a single character, and make it at least 1.  The check
1470 	 * interval should also be less than the timeout.
1471 	 *
1472 	 * Note: we have to use pretty tight timings here to satisfy
1473 	 * the NIST-PCTS.
1474 	 */
1475 	char_time = (info->timeout - HZ / 50) / info->xmit_fifo_size;
1476 	char_time = char_time / 5;
1477 	if (char_time == 0)
1478 		char_time = 1;
1479 	if (timeout && timeout < char_time)
1480 		char_time = timeout;
1481 	/*
1482 	 * If the transmitter hasn't cleared in twice the approximate
1483 	 * amount of time to send the entire FIFO, it probably won't
1484 	 * ever clear.  This assumes the UART isn't doing flow
1485 	 * control, which is currently the case.  Hence, if it ever
1486 	 * takes longer than info->timeout, this is probably due to a
1487 	 * UART bug of some kind.  So, we clamp the timeout parameter at
1488 	 * 2*info->timeout.
1489 	 */
1490 	if (!timeout || timeout > 2 * info->timeout)
1491 		timeout = 2 * info->timeout;
1492 
1493 	spin_lock_irqsave(&info->slock, flags);
1494 	while (!((lsr = inb(info->ioaddr + UART_LSR)) & UART_LSR_TEMT)) {
1495 		spin_unlock_irqrestore(&info->slock, flags);
1496 		schedule_timeout_interruptible(char_time);
1497 		spin_lock_irqsave(&info->slock, flags);
1498 		if (signal_pending(current))
1499 			break;
1500 		if (timeout && time_after(jiffies, orig_jiffies + timeout))
1501 			break;
1502 	}
1503 	spin_unlock_irqrestore(&info->slock, flags);
1504 	set_current_state(TASK_RUNNING);
1505 }
1506 
1507 /*
1508  * This routine is called by tty_hangup() when a hangup is signaled.
1509  */
1510 static void mxser_hangup(struct tty_struct *tty)
1511 {
1512 	struct mxser_port *info = tty->driver_data;
1513 
1514 	mxser_flush_buffer(tty);
1515 	tty_port_hangup(&info->port);
1516 }
1517 
1518 /*
1519  * mxser_rs_break() --- routine which turns the break handling on or off
1520  */
1521 static int mxser_rs_break(struct tty_struct *tty, int break_state)
1522 {
1523 	struct mxser_port *info = tty->driver_data;
1524 	unsigned long flags;
1525 	u8 lcr;
1526 
1527 	spin_lock_irqsave(&info->slock, flags);
1528 	lcr = inb(info->ioaddr + UART_LCR);
1529 	if (break_state == -1)
1530 		lcr |= UART_LCR_SBC;
1531 	else
1532 		lcr &= ~UART_LCR_SBC;
1533 	outb(lcr, info->ioaddr + UART_LCR);
1534 	spin_unlock_irqrestore(&info->slock, flags);
1535 
1536 	return 0;
1537 }
1538 
1539 static bool mxser_receive_chars_new(struct tty_struct *tty,
1540 		struct mxser_port *port, u8 status)
1541 {
1542 	enum mxser_must_hwid hwid = port->board->must_hwid;
1543 	u8 gdl;
1544 
1545 	if (hwid == MOXA_OTHER_UART)
1546 		return false;
1547 	if (status & UART_LSR_BRK_ERROR_BITS)
1548 		return false;
1549 	if (hwid == MOXA_MUST_MU860_HWID && (status & MOXA_MUST_LSR_RERR))
1550 		return false;
1551 	if (status & MOXA_MUST_LSR_RERR)
1552 		return false;
1553 
1554 	gdl = inb(port->ioaddr + MOXA_MUST_GDL_REGISTER);
1555 	if (hwid == MOXA_MUST_MU150_HWID)
1556 		gdl &= MOXA_MUST_GDL_MASK;
1557 
1558 	if (gdl >= tty->receive_room && !port->ldisc_stop_rx)
1559 		mxser_stoprx(tty);
1560 
1561 	while (gdl--) {
1562 		u8 ch = inb(port->ioaddr + UART_RX);
1563 		tty_insert_flip_char(&port->port, ch, 0);
1564 	}
1565 
1566 	return true;
1567 }
1568 
1569 static u8 mxser_receive_chars_old(struct tty_struct *tty,
1570 		                struct mxser_port *port, u8 status)
1571 {
1572 	enum mxser_must_hwid hwid = port->board->must_hwid;
1573 	int recv_room = tty->receive_room;
1574 	int ignored = 0;
1575 	int max = 256;
1576 	int cnt = 0;
1577 	u8 ch;
1578 
1579 	do {
1580 		if (max-- < 0)
1581 			break;
1582 
1583 		ch = inb(port->ioaddr + UART_RX);
1584 		if (hwid && (status & UART_LSR_OE))
1585 			outb(UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
1586 					MOXA_MUST_FCR_GDA_MODE_ENABLE,
1587 					port->ioaddr + UART_FCR);
1588 		status &= port->read_status_mask;
1589 		if (status & port->ignore_status_mask) {
1590 			if (++ignored > 100)
1591 				break;
1592 		} else {
1593 			char flag = 0;
1594 			if (status & UART_LSR_BRK_ERROR_BITS) {
1595 				if (status & UART_LSR_BI) {
1596 					flag = TTY_BREAK;
1597 					port->icount.brk++;
1598 
1599 					if (port->port.flags & ASYNC_SAK)
1600 						do_SAK(tty);
1601 				} else if (status & UART_LSR_PE) {
1602 					flag = TTY_PARITY;
1603 					port->icount.parity++;
1604 				} else if (status & UART_LSR_FE) {
1605 					flag = TTY_FRAME;
1606 					port->icount.frame++;
1607 				} else if (status & UART_LSR_OE) {
1608 					flag = TTY_OVERRUN;
1609 					port->icount.overrun++;
1610 				}
1611 			}
1612 			tty_insert_flip_char(&port->port, ch, flag);
1613 			cnt++;
1614 			if (cnt >= recv_room) {
1615 				if (!port->ldisc_stop_rx)
1616 					mxser_stoprx(tty);
1617 				break;
1618 			}
1619 
1620 		}
1621 
1622 		if (hwid)
1623 			break;
1624 
1625 		status = inb(port->ioaddr + UART_LSR);
1626 	} while (status & UART_LSR_DR);
1627 
1628 	return status;
1629 }
1630 
1631 static u8 mxser_receive_chars(struct tty_struct *tty,
1632 		struct mxser_port *port, u8 status)
1633 {
1634 	if (tty->receive_room == 0 && !port->ldisc_stop_rx)
1635 		mxser_stoprx(tty);
1636 
1637 	if (!mxser_receive_chars_new(tty, port, status))
1638 		status = mxser_receive_chars_old(tty, port, status);
1639 
1640 	tty_flip_buffer_push(&port->port);
1641 
1642 	return status;
1643 }
1644 
1645 static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port)
1646 {
1647 	int count, cnt;
1648 
1649 	if (port->x_char) {
1650 		outb(port->x_char, port->ioaddr + UART_TX);
1651 		port->x_char = 0;
1652 		port->icount.tx++;
1653 		return;
1654 	}
1655 
1656 	if (port->port.xmit_buf == NULL)
1657 		return;
1658 
1659 	if (!port->xmit_cnt || tty->flow.stopped ||
1660 			(tty->hw_stopped && !mxser_16550A_or_MUST(port))) {
1661 		__mxser_stop_tx(port);
1662 		return;
1663 	}
1664 
1665 	cnt = port->xmit_cnt;
1666 	count = port->xmit_fifo_size;
1667 	do {
1668 		outb(port->port.xmit_buf[port->xmit_tail++],
1669 			port->ioaddr + UART_TX);
1670 		port->xmit_tail = port->xmit_tail & (SERIAL_XMIT_SIZE - 1);
1671 		if (!--port->xmit_cnt)
1672 			break;
1673 	} while (--count > 0);
1674 
1675 	port->icount.tx += (cnt - port->xmit_cnt);
1676 
1677 	if (port->xmit_cnt < WAKEUP_CHARS)
1678 		tty_wakeup(tty);
1679 
1680 	if (!port->xmit_cnt)
1681 		__mxser_stop_tx(port);
1682 }
1683 
1684 static bool mxser_port_isr(struct mxser_port *port)
1685 {
1686 	struct tty_struct *tty;
1687 	u8 iir, msr, status;
1688 	bool error = false;
1689 
1690 	iir = inb(port->ioaddr + UART_IIR);
1691 	if (iir & UART_IIR_NO_INT)
1692 		return true;
1693 
1694 	iir &= MOXA_MUST_IIR_MASK;
1695 	tty = tty_port_tty_get(&port->port);
1696 	if (!tty || port->closing || !tty_port_initialized(&port->port)) {
1697 		status = inb(port->ioaddr + UART_LSR);
1698 		outb(MOXA_MUST_FCR_GDA_MODE_ENABLE | UART_FCR_ENABLE_FIFO |
1699 				UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
1700 				port->ioaddr + UART_FCR);
1701 		inb(port->ioaddr + UART_MSR);
1702 
1703 		error = true;
1704 		goto put_tty;
1705 	}
1706 
1707 	status = inb(port->ioaddr + UART_LSR);
1708 
1709 	if (port->board->must_hwid) {
1710 		if (iir == MOXA_MUST_IIR_GDA ||
1711 		    iir == MOXA_MUST_IIR_RDA ||
1712 		    iir == MOXA_MUST_IIR_RTO ||
1713 		    iir == MOXA_MUST_IIR_LSR)
1714 			status = mxser_receive_chars(tty, port, status);
1715 	} else {
1716 		status &= port->read_status_mask;
1717 		if (status & UART_LSR_DR)
1718 			status = mxser_receive_chars(tty, port, status);
1719 	}
1720 
1721 	msr = inb(port->ioaddr + UART_MSR);
1722 	if (msr & UART_MSR_ANY_DELTA)
1723 		mxser_check_modem_status(tty, port, msr);
1724 
1725 	if (port->board->must_hwid) {
1726 		if (iir == 0x02 && (status & UART_LSR_THRE))
1727 			mxser_transmit_chars(tty, port);
1728 	} else {
1729 		if (status & UART_LSR_THRE)
1730 			mxser_transmit_chars(tty, port);
1731 	}
1732 
1733 put_tty:
1734 	tty_kref_put(tty);
1735 
1736 	return error;
1737 }
1738 
1739 /*
1740  * This is the serial driver's generic interrupt routine
1741  */
1742 static irqreturn_t mxser_interrupt(int irq, void *dev_id)
1743 {
1744 	struct mxser_board *brd = dev_id;
1745 	struct mxser_port *port;
1746 	unsigned int int_cnt, pass_counter = 0;
1747 	unsigned int i, max = brd->nports;
1748 	int handled = IRQ_NONE;
1749 	u8 irqbits, bits, mask = BIT(max) - 1;
1750 
1751 	while (pass_counter++ < MXSER_ISR_PASS_LIMIT) {
1752 		irqbits = inb(brd->vector) & mask;
1753 		if (irqbits == mask)
1754 			break;
1755 
1756 		handled = IRQ_HANDLED;
1757 		for (i = 0, bits = 1; i < max; i++, irqbits |= bits, bits <<= 1) {
1758 			if (irqbits == mask)
1759 				break;
1760 			if (bits & irqbits)
1761 				continue;
1762 			port = &brd->ports[i];
1763 
1764 			int_cnt = 0;
1765 			spin_lock(&port->slock);
1766 			do {
1767 				if (mxser_port_isr(port))
1768 					break;
1769 			} while (int_cnt++ < MXSER_ISR_PASS_LIMIT);
1770 			spin_unlock(&port->slock);
1771 		}
1772 	}
1773 
1774 	return handled;
1775 }
1776 
1777 static const struct tty_operations mxser_ops = {
1778 	.open = mxser_open,
1779 	.close = mxser_close,
1780 	.write = mxser_write,
1781 	.put_char = mxser_put_char,
1782 	.flush_chars = mxser_flush_chars,
1783 	.write_room = mxser_write_room,
1784 	.chars_in_buffer = mxser_chars_in_buffer,
1785 	.flush_buffer = mxser_flush_buffer,
1786 	.ioctl = mxser_ioctl,
1787 	.throttle = mxser_throttle,
1788 	.unthrottle = mxser_unthrottle,
1789 	.set_termios = mxser_set_termios,
1790 	.stop = mxser_stop,
1791 	.start = mxser_start,
1792 	.hangup = mxser_hangup,
1793 	.break_ctl = mxser_rs_break,
1794 	.wait_until_sent = mxser_wait_until_sent,
1795 	.tiocmget = mxser_tiocmget,
1796 	.tiocmset = mxser_tiocmset,
1797 	.set_serial = mxser_set_serial_info,
1798 	.get_serial = mxser_get_serial_info,
1799 	.get_icount = mxser_get_icount,
1800 };
1801 
1802 static const struct tty_port_operations mxser_port_ops = {
1803 	.carrier_raised = mxser_carrier_raised,
1804 	.dtr_rts = mxser_dtr_rts,
1805 	.activate = mxser_activate,
1806 	.shutdown = mxser_shutdown_port,
1807 };
1808 
1809 /*
1810  * The MOXA Smartio/Industio serial driver boot-time initialization code!
1811  */
1812 
1813 static void mxser_initbrd(struct mxser_board *brd, bool high_baud)
1814 {
1815 	struct mxser_port *info;
1816 	unsigned int i;
1817 	bool is_mu860;
1818 
1819 	brd->must_hwid = mxser_must_get_hwid(brd->ports[0].ioaddr);
1820 	is_mu860 = brd->must_hwid == MOXA_MUST_MU860_HWID;
1821 
1822 	for (i = 0; i < UART_INFO_NUM; i++) {
1823 		if (Gpci_uart_info[i].type == brd->must_hwid) {
1824 			brd->max_baud = Gpci_uart_info[i].max_baud;
1825 
1826 			/* exception....CP-102 */
1827 			if (high_baud)
1828 				brd->max_baud = 921600;
1829 			break;
1830 		}
1831 	}
1832 
1833 	if (is_mu860) {
1834 		/* set to RS232 mode by default */
1835 		outb(0, brd->vector + 4);
1836 		outb(0, brd->vector + 0x0c);
1837 	}
1838 
1839 	for (i = 0; i < brd->nports; i++) {
1840 		info = &brd->ports[i];
1841 		if (is_mu860) {
1842 			if (i < 4)
1843 				info->opmode_ioaddr = brd->vector + 4;
1844 			else
1845 				info->opmode_ioaddr = brd->vector + 0x0c;
1846 		}
1847 		tty_port_init(&info->port);
1848 		info->port.ops = &mxser_port_ops;
1849 		info->board = brd;
1850 		info->ldisc_stop_rx = 0;
1851 
1852 		/* Enhance mode enabled here */
1853 		if (brd->must_hwid != MOXA_OTHER_UART)
1854 			mxser_must_set_enhance_mode(info->ioaddr, true);
1855 
1856 		info->type = PORT_16550A;
1857 
1858 		mxser_process_txrx_fifo(info);
1859 
1860 		info->port.close_delay = 5 * HZ / 10;
1861 		info->port.closing_wait = 30 * HZ;
1862 		spin_lock_init(&info->slock);
1863 
1864 		/* before set INT ISR, disable all int */
1865 		outb(inb(info->ioaddr + UART_IER) & 0xf0,
1866 			info->ioaddr + UART_IER);
1867 	}
1868 }
1869 
1870 static int mxser_probe(struct pci_dev *pdev,
1871 		const struct pci_device_id *ent)
1872 {
1873 	struct mxser_board *brd;
1874 	unsigned int i, base;
1875 	unsigned long ioaddress;
1876 	unsigned short nports = MXSER_NPORTS(ent->driver_data);
1877 	struct device *tty_dev;
1878 	int retval = -EINVAL;
1879 
1880 	i = find_first_zero_bit(mxser_boards, MXSER_BOARDS);
1881 	if (i >= MXSER_BOARDS) {
1882 		dev_err(&pdev->dev, "too many boards found (maximum %d), board "
1883 				"not configured\n", MXSER_BOARDS);
1884 		goto err;
1885 	}
1886 
1887 	brd = devm_kzalloc(&pdev->dev, struct_size(brd, ports, nports),
1888 			GFP_KERNEL);
1889 	if (!brd)
1890 		goto err;
1891 
1892 	brd->idx = i;
1893 	__set_bit(brd->idx, mxser_boards);
1894 	base = i * MXSER_PORTS_PER_BOARD;
1895 
1896 	retval = pcim_enable_device(pdev);
1897 	if (retval) {
1898 		dev_err(&pdev->dev, "PCI enable failed\n");
1899 		goto err_zero;
1900 	}
1901 
1902 	/* io address */
1903 	ioaddress = pci_resource_start(pdev, 2);
1904 	retval = pci_request_region(pdev, 2, "mxser(IO)");
1905 	if (retval)
1906 		goto err_zero;
1907 
1908 	brd->nports = nports;
1909 	for (i = 0; i < nports; i++)
1910 		brd->ports[i].ioaddr = ioaddress + 8 * i;
1911 
1912 	/* vector */
1913 	ioaddress = pci_resource_start(pdev, 3);
1914 	retval = pci_request_region(pdev, 3, "mxser(vector)");
1915 	if (retval)
1916 		goto err_zero;
1917 	brd->vector = ioaddress;
1918 
1919 	/* irq */
1920 	brd->irq = pdev->irq;
1921 
1922 	mxser_initbrd(brd, ent->driver_data & MXSER_HIGHBAUD);
1923 
1924 	retval = devm_request_irq(&pdev->dev, brd->irq, mxser_interrupt,
1925 			IRQF_SHARED, "mxser", brd);
1926 	if (retval) {
1927 		dev_err(&pdev->dev, "request irq failed");
1928 		goto err_relbrd;
1929 	}
1930 
1931 	for (i = 0; i < nports; i++) {
1932 		tty_dev = tty_port_register_device(&brd->ports[i].port,
1933 				mxvar_sdriver, base + i, &pdev->dev);
1934 		if (IS_ERR(tty_dev)) {
1935 			retval = PTR_ERR(tty_dev);
1936 			for (; i > 0; i--)
1937 				tty_unregister_device(mxvar_sdriver,
1938 					base + i - 1);
1939 			goto err_relbrd;
1940 		}
1941 	}
1942 
1943 	pci_set_drvdata(pdev, brd);
1944 
1945 	return 0;
1946 err_relbrd:
1947 	for (i = 0; i < nports; i++)
1948 		tty_port_destroy(&brd->ports[i].port);
1949 err_zero:
1950 	__clear_bit(brd->idx, mxser_boards);
1951 err:
1952 	return retval;
1953 }
1954 
1955 static void mxser_remove(struct pci_dev *pdev)
1956 {
1957 	struct mxser_board *brd = pci_get_drvdata(pdev);
1958 	unsigned int i, base = brd->idx * MXSER_PORTS_PER_BOARD;
1959 
1960 	for (i = 0; i < brd->nports; i++) {
1961 		tty_unregister_device(mxvar_sdriver, base + i);
1962 		tty_port_destroy(&brd->ports[i].port);
1963 	}
1964 
1965 	__clear_bit(brd->idx, mxser_boards);
1966 }
1967 
1968 static struct pci_driver mxser_driver = {
1969 	.name = "mxser",
1970 	.id_table = mxser_pcibrds,
1971 	.probe = mxser_probe,
1972 	.remove = mxser_remove
1973 };
1974 
1975 static int __init mxser_module_init(void)
1976 {
1977 	int retval;
1978 
1979 	mxvar_sdriver = alloc_tty_driver(MXSER_PORTS);
1980 	if (!mxvar_sdriver)
1981 		return -ENOMEM;
1982 
1983 	/* Initialize the tty_driver structure */
1984 	mxvar_sdriver->name = "ttyMI";
1985 	mxvar_sdriver->major = ttymajor;
1986 	mxvar_sdriver->minor_start = 0;
1987 	mxvar_sdriver->type = TTY_DRIVER_TYPE_SERIAL;
1988 	mxvar_sdriver->subtype = SERIAL_TYPE_NORMAL;
1989 	mxvar_sdriver->init_termios = tty_std_termios;
1990 	mxvar_sdriver->init_termios.c_cflag = B9600|CS8|CREAD|HUPCL|CLOCAL;
1991 	mxvar_sdriver->flags = TTY_DRIVER_REAL_RAW|TTY_DRIVER_DYNAMIC_DEV;
1992 	tty_set_operations(mxvar_sdriver, &mxser_ops);
1993 
1994 	retval = tty_register_driver(mxvar_sdriver);
1995 	if (retval) {
1996 		printk(KERN_ERR "Couldn't install MOXA Smartio/Industio family "
1997 				"tty driver !\n");
1998 		goto err_put;
1999 	}
2000 
2001 	retval = pci_register_driver(&mxser_driver);
2002 	if (retval) {
2003 		printk(KERN_ERR "mxser: can't register pci driver\n");
2004 		goto err_unr;
2005 	}
2006 
2007 	return 0;
2008 err_unr:
2009 	tty_unregister_driver(mxvar_sdriver);
2010 err_put:
2011 	put_tty_driver(mxvar_sdriver);
2012 	return retval;
2013 }
2014 
2015 static void __exit mxser_module_exit(void)
2016 {
2017 	pci_unregister_driver(&mxser_driver);
2018 	tty_unregister_driver(mxvar_sdriver);
2019 	put_tty_driver(mxvar_sdriver);
2020 }
2021 
2022 module_init(mxser_module_init);
2023 module_exit(mxser_module_exit);
2024