xref: /linux/drivers/tty/mxser.c (revision 68a052239fc4b351e961f698b824f7654a346091)
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_MOXA_RC7000	0x0001
163 #define PCI_DEVICE_ID_MOXA_CP102	0x1020
164 #define PCI_DEVICE_ID_MOXA_CP102UL	0x1021
165 #define PCI_DEVICE_ID_MOXA_CP102U	0x1022
166 #define PCI_DEVICE_ID_MOXA_CP102UF	0x1023
167 #define PCI_DEVICE_ID_MOXA_C104		0x1040
168 #define PCI_DEVICE_ID_MOXA_CP104U	0x1041
169 #define PCI_DEVICE_ID_MOXA_CP104JU	0x1042
170 #define PCI_DEVICE_ID_MOXA_CP104EL	0x1043
171 #define PCI_DEVICE_ID_MOXA_POS104UL	0x1044
172 #define PCI_DEVICE_ID_MOXA_CB108	0x1080
173 #define PCI_DEVICE_ID_MOXA_CP112UL	0x1120
174 #define PCI_DEVICE_ID_MOXA_CT114	0x1140
175 #define PCI_DEVICE_ID_MOXA_CP114	0x1141
176 #define PCI_DEVICE_ID_MOXA_CB114	0x1142
177 #define PCI_DEVICE_ID_MOXA_CP114UL	0x1143
178 #define PCI_DEVICE_ID_MOXA_CP118U	0x1180
179 #define PCI_DEVICE_ID_MOXA_CP118EL	0x1181
180 #define PCI_DEVICE_ID_MOXA_CP132	0x1320
181 #define PCI_DEVICE_ID_MOXA_CP132U	0x1321
182 #define PCI_DEVICE_ID_MOXA_CP134U	0x1340
183 #define PCI_DEVICE_ID_MOXA_CB134I	0x1341
184 #define PCI_DEVICE_ID_MOXA_CP138U	0x1380
185 #define PCI_DEVICE_ID_MOXA_C168		0x1680
186 #define PCI_DEVICE_ID_MOXA_CP168U	0x1681
187 #define PCI_DEVICE_ID_MOXA_CP168EL	0x1682
188 
189 #define MXSER_NPORTS(ddata)		((ddata) & 0xffU)
190 #define MXSER_HIGHBAUD			0x0100
191 
192 enum mxser_must_hwid {
193 	MOXA_OTHER_UART		= 0x00,
194 	MOXA_MUST_MU150_HWID	= 0x01,
195 	MOXA_MUST_MU860_HWID	= 0x02,
196 };
197 
198 static const struct {
199 	u8 type;
200 	u8 fifo_size;
201 	u8 rx_high_water;
202 	u8 rx_low_water;
203 	speed_t max_baud;
204 } Gpci_uart_info[] = {
205 	{ MOXA_OTHER_UART,	 16, 14,  1, 921600 },
206 	{ MOXA_MUST_MU150_HWID,	 64, 48, 16, 230400 },
207 	{ MOXA_MUST_MU860_HWID, 128, 96, 32, 921600 }
208 };
209 #define UART_INFO_NUM	ARRAY_SIZE(Gpci_uart_info)
210 
211 static const struct pci_device_id mxser_pcibrds[] = {
212 	{ PCI_DEVICE_DATA(MOXA, C168,		8) },
213 	{ PCI_DEVICE_DATA(MOXA, C104,		4) },
214 	{ PCI_DEVICE_DATA(MOXA, CP132,		2) },
215 	{ PCI_DEVICE_DATA(MOXA, CP114,		4) },
216 	{ PCI_DEVICE_DATA(MOXA, CT114,		4) },
217 	{ PCI_DEVICE_DATA(MOXA, CP102,		2 | MXSER_HIGHBAUD) },
218 	{ PCI_DEVICE_DATA(MOXA, CP104U,		4) },
219 	{ PCI_DEVICE_DATA(MOXA, CP168U,		8) },
220 	{ PCI_DEVICE_DATA(MOXA, CP132U,		2) },
221 	{ PCI_DEVICE_DATA(MOXA, CP134U,		4) },
222 	{ PCI_DEVICE_DATA(MOXA, CP104JU,	4) },
223 	{ PCI_DEVICE_DATA(MOXA, RC7000,		8) }, /* RC7000 */
224 	{ PCI_DEVICE_DATA(MOXA, CP118U,		8) },
225 	{ PCI_DEVICE_DATA(MOXA, CP102UL,	2) },
226 	{ PCI_DEVICE_DATA(MOXA, CP102U,		2) },
227 	{ PCI_DEVICE_DATA(MOXA, CP118EL,	8) },
228 	{ PCI_DEVICE_DATA(MOXA, CP168EL,	8) },
229 	{ PCI_DEVICE_DATA(MOXA, CP104EL,	4) },
230 	{ PCI_DEVICE_DATA(MOXA, CB108,		8) },
231 	{ PCI_DEVICE_DATA(MOXA, CB114,		4) },
232 	{ PCI_DEVICE_DATA(MOXA, CB134I,		4) },
233 	{ PCI_DEVICE_DATA(MOXA, CP138U,		8) },
234 	{ PCI_DEVICE_DATA(MOXA, POS104UL,	4) },
235 	{ PCI_DEVICE_DATA(MOXA, CP114UL,	4) },
236 	{ PCI_DEVICE_DATA(MOXA, CP102UF,	2) },
237 	{ PCI_DEVICE_DATA(MOXA, CP112UL,	2) },
238 	{ }
239 };
240 MODULE_DEVICE_TABLE(pci, mxser_pcibrds);
241 
242 static int ttymajor = MXSERMAJOR;
243 
244 /* Variables for insmod */
245 
246 MODULE_AUTHOR("Casper Yang");
247 MODULE_DESCRIPTION("MOXA Smartio/Industio Family Multiport Board Device Driver");
248 module_param(ttymajor, int, 0);
249 MODULE_LICENSE("GPL");
250 
251 struct mxser_board;
252 
253 struct mxser_port {
254 	struct tty_port port;
255 	struct mxser_board *board;
256 
257 	unsigned long ioaddr;
258 	unsigned long opmode_ioaddr;
259 
260 	u8 rx_high_water;
261 	u8 rx_low_water;
262 	int type;		/* UART type */
263 
264 	u8 x_char;		/* xon/xoff character */
265 	u8 IER;			/* Interrupt Enable Register */
266 	u8 MCR;			/* Modem control register */
267 	u8 FCR;			/* FIFO control register */
268 
269 	struct async_icount icount; /* kernel counters for 4 input interrupts */
270 	unsigned int timeout;
271 
272 	u8 read_status_mask;
273 	u8 ignore_status_mask;
274 	u8 xmit_fifo_size;
275 
276 	spinlock_t slock;
277 };
278 
279 struct mxser_board {
280 	unsigned int idx;
281 	unsigned short nports;
282 	int irq;
283 	unsigned long vector;
284 
285 	enum mxser_must_hwid must_hwid;
286 	speed_t max_baud;
287 
288 	struct mxser_port ports[] /* __counted_by(nports) */;
289 };
290 
291 static DECLARE_BITMAP(mxser_boards, MXSER_BOARDS);
292 static struct tty_driver *mxvar_sdriver;
293 
294 static u8 __mxser_must_set_EFR(unsigned long baseio, u8 clear, u8 set,
295 		bool restore_LCR)
296 {
297 	u8 oldlcr, efr;
298 
299 	oldlcr = inb(baseio + UART_LCR);
300 	outb(MOXA_MUST_ENTER_ENHANCED, baseio + UART_LCR);
301 
302 	efr = inb(baseio + MOXA_MUST_EFR_REGISTER);
303 	efr &= ~clear;
304 	efr |= set;
305 
306 	outb(efr, baseio + MOXA_MUST_EFR_REGISTER);
307 
308 	if (restore_LCR)
309 		outb(oldlcr, baseio + UART_LCR);
310 
311 	return oldlcr;
312 }
313 
314 static u8 mxser_must_select_bank(unsigned long baseio, u8 bank)
315 {
316 	return __mxser_must_set_EFR(baseio, MOXA_MUST_EFR_BANK_MASK, bank,
317 			false);
318 }
319 
320 static void mxser_set_must_xon1_value(unsigned long baseio, u8 value)
321 {
322 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK0);
323 	outb(value, baseio + MOXA_MUST_XON1_REGISTER);
324 	outb(oldlcr, baseio + UART_LCR);
325 }
326 
327 static void mxser_set_must_xoff1_value(unsigned long baseio, u8 value)
328 {
329 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK0);
330 	outb(value, baseio + MOXA_MUST_XOFF1_REGISTER);
331 	outb(oldlcr, baseio + UART_LCR);
332 }
333 
334 static void mxser_set_must_fifo_value(struct mxser_port *info)
335 {
336 	u8 oldlcr = mxser_must_select_bank(info->ioaddr, MOXA_MUST_EFR_BANK1);
337 	outb(info->rx_high_water, info->ioaddr + MOXA_MUST_RBRTH_REGISTER);
338 	outb(info->rx_high_water, info->ioaddr + MOXA_MUST_RBRTI_REGISTER);
339 	outb(info->rx_low_water, info->ioaddr + MOXA_MUST_RBRTL_REGISTER);
340 	outb(oldlcr, info->ioaddr + UART_LCR);
341 }
342 
343 static void mxser_set_must_enum_value(unsigned long baseio, u8 value)
344 {
345 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK2);
346 	outb(value, baseio + MOXA_MUST_ENUM_REGISTER);
347 	outb(oldlcr, baseio + UART_LCR);
348 }
349 
350 static u8 mxser_get_must_hardware_id(unsigned long baseio)
351 {
352 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK2);
353 	u8 id = inb(baseio + MOXA_MUST_HWID_REGISTER);
354 	outb(oldlcr, baseio + UART_LCR);
355 
356 	return id;
357 }
358 
359 static void mxser_must_set_EFR(unsigned long baseio, u8 clear, u8 set)
360 {
361 	__mxser_must_set_EFR(baseio, clear, set, true);
362 }
363 
364 static void mxser_must_set_enhance_mode(unsigned long baseio, bool enable)
365 {
366 	mxser_must_set_EFR(baseio,
367 			enable ? 0 : MOXA_MUST_EFR_EFRB_ENABLE,
368 			enable ? MOXA_MUST_EFR_EFRB_ENABLE : 0);
369 }
370 
371 static void mxser_must_no_sw_flow_control(unsigned long baseio)
372 {
373 	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_MASK, 0);
374 }
375 
376 static void mxser_must_set_tx_sw_flow_control(unsigned long baseio, bool enable)
377 {
378 	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_TX_MASK,
379 			enable ? MOXA_MUST_EFR_SF_TX1 : 0);
380 }
381 
382 static void mxser_must_set_rx_sw_flow_control(unsigned long baseio, bool enable)
383 {
384 	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_RX_MASK,
385 			enable ? MOXA_MUST_EFR_SF_RX1 : 0);
386 }
387 
388 static enum mxser_must_hwid mxser_must_get_hwid(unsigned long io)
389 {
390 	u8 oldmcr, hwid;
391 	int i;
392 
393 	outb(0, io + UART_LCR);
394 	mxser_must_set_enhance_mode(io, false);
395 	oldmcr = inb(io + UART_MCR);
396 	outb(0, io + UART_MCR);
397 	mxser_set_must_xon1_value(io, 0x11);
398 	if (inb(io + UART_MCR) != 0) {
399 		outb(oldmcr, io + UART_MCR);
400 		return MOXA_OTHER_UART;
401 	}
402 
403 	hwid = mxser_get_must_hardware_id(io);
404 	for (i = 1; i < UART_INFO_NUM; i++) /* 0 = OTHER_UART */
405 		if (hwid == Gpci_uart_info[i].type)
406 			return hwid;
407 
408 	return MOXA_OTHER_UART;
409 }
410 
411 static bool mxser_16550A_or_MUST(struct mxser_port *info)
412 {
413 	return info->type == PORT_16550A || info->board->must_hwid;
414 }
415 
416 static void mxser_process_txrx_fifo(struct mxser_port *info)
417 {
418 	unsigned int i;
419 
420 	if (info->type == PORT_16450 || info->type == PORT_8250) {
421 		info->rx_high_water = 1;
422 		info->rx_low_water = 1;
423 		info->xmit_fifo_size = 1;
424 		return;
425 	}
426 
427 	for (i = 0; i < UART_INFO_NUM; i++)
428 		if (info->board->must_hwid == Gpci_uart_info[i].type) {
429 			info->rx_low_water = Gpci_uart_info[i].rx_low_water;
430 			info->rx_high_water = Gpci_uart_info[i].rx_high_water;
431 			info->xmit_fifo_size = Gpci_uart_info[i].fifo_size;
432 			break;
433 		}
434 }
435 
436 static void __mxser_start_tx(struct mxser_port *info)
437 {
438 	outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
439 	info->IER |= UART_IER_THRI;
440 	outb(info->IER, info->ioaddr + UART_IER);
441 }
442 
443 static void mxser_start_tx(struct mxser_port *info)
444 {
445 	guard(spinlock_irqsave)(&info->slock);
446 	__mxser_start_tx(info);
447 }
448 
449 static void __mxser_stop_tx(struct mxser_port *info)
450 {
451 	info->IER &= ~UART_IER_THRI;
452 	outb(info->IER, info->ioaddr + UART_IER);
453 }
454 
455 static bool mxser_carrier_raised(struct tty_port *port)
456 {
457 	struct mxser_port *mp = container_of(port, struct mxser_port, port);
458 
459 	return inb(mp->ioaddr + UART_MSR) & UART_MSR_DCD;
460 }
461 
462 static void mxser_dtr_rts(struct tty_port *port, bool active)
463 {
464 	struct mxser_port *mp = container_of(port, struct mxser_port, port);
465 	u8 mcr;
466 
467 	guard(spinlock_irqsave)(&mp->slock);
468 	mcr = inb(mp->ioaddr + UART_MCR);
469 	if (active)
470 		mcr |= UART_MCR_DTR | UART_MCR_RTS;
471 	else
472 		mcr &= ~(UART_MCR_DTR | UART_MCR_RTS);
473 	outb(mcr, mp->ioaddr + UART_MCR);
474 }
475 
476 static int mxser_set_baud(struct tty_struct *tty, speed_t newspd)
477 {
478 	struct mxser_port *info = tty->driver_data;
479 	unsigned int quot = 0, baud;
480 	unsigned char cval;
481 	u64 timeout;
482 
483 	if (newspd > info->board->max_baud)
484 		return -1;
485 
486 	if (newspd == 134) {
487 		quot = 2 * MXSER_BAUD_BASE / 269;
488 		tty_encode_baud_rate(tty, 134, 134);
489 	} else if (newspd) {
490 		quot = MXSER_BAUD_BASE / newspd;
491 		if (quot == 0)
492 			quot = 1;
493 		baud = MXSER_BAUD_BASE / quot;
494 		tty_encode_baud_rate(tty, baud, baud);
495 	} else {
496 		quot = 0;
497 	}
498 
499 	/*
500 	 * worst case (128 * 1000 * 10 * 18432) needs 35 bits, so divide in the
501 	 * u64 domain
502 	 */
503 	timeout = (u64)info->xmit_fifo_size * HZ * 10 * quot;
504 	do_div(timeout, MXSER_BAUD_BASE);
505 	info->timeout = timeout + HZ / 50; /* Add .02 seconds of slop */
506 
507 	if (quot) {
508 		info->MCR |= UART_MCR_DTR;
509 		outb(info->MCR, info->ioaddr + UART_MCR);
510 	} else {
511 		info->MCR &= ~UART_MCR_DTR;
512 		outb(info->MCR, info->ioaddr + UART_MCR);
513 		return 0;
514 	}
515 
516 	cval = inb(info->ioaddr + UART_LCR);
517 
518 	outb(cval | UART_LCR_DLAB, info->ioaddr + UART_LCR);	/* set DLAB */
519 
520 	outb(quot & 0xff, info->ioaddr + UART_DLL);	/* LS of divisor */
521 	outb(quot >> 8, info->ioaddr + UART_DLM);	/* MS of divisor */
522 	outb(cval, info->ioaddr + UART_LCR);	/* reset DLAB */
523 
524 	if (C_BAUD(tty) == BOTHER) {
525 		quot = MXSER_BAUD_BASE % newspd;
526 		quot *= 8;
527 		if (quot % newspd > newspd / 2) {
528 			quot /= newspd;
529 			quot++;
530 		} else
531 			quot /= newspd;
532 
533 		mxser_set_must_enum_value(info->ioaddr, quot);
534 	} else {
535 		mxser_set_must_enum_value(info->ioaddr, 0);
536 	}
537 
538 	return 0;
539 }
540 
541 static void mxser_handle_cts(struct tty_struct *tty, struct mxser_port *info,
542 		u8 msr)
543 {
544 	bool cts = msr & UART_MSR_CTS;
545 
546 	if (tty->hw_stopped) {
547 		if (cts) {
548 			tty->hw_stopped = false;
549 
550 			if (!mxser_16550A_or_MUST(info))
551 				__mxser_start_tx(info);
552 			tty_wakeup(tty);
553 		}
554 		return;
555 	} else if (cts)
556 		return;
557 
558 	tty->hw_stopped = true;
559 	if (!mxser_16550A_or_MUST(info))
560 		__mxser_stop_tx(info);
561 }
562 
563 /*
564  * This routine is called to set the UART divisor registers to match
565  * the specified baud rate for a serial port.
566  */
567 static void mxser_change_speed(struct tty_struct *tty,
568 			       const struct ktermios *old_termios)
569 {
570 	struct mxser_port *info = tty->driver_data;
571 	unsigned cflag, cval;
572 
573 	cflag = tty->termios.c_cflag;
574 
575 	if (mxser_set_baud(tty, tty_get_baud_rate(tty))) {
576 		/* Use previous rate on a failure */
577 		if (old_termios) {
578 			speed_t baud = tty_termios_baud_rate(old_termios);
579 			tty_encode_baud_rate(tty, baud, baud);
580 		}
581 	}
582 
583 	/* byte size and parity */
584 	cval = UART_LCR_WLEN(tty_get_char_size(tty->termios.c_cflag));
585 
586 	if (cflag & CSTOPB)
587 		cval |= UART_LCR_STOP;
588 	if (cflag & PARENB)
589 		cval |= UART_LCR_PARITY;
590 	if (!(cflag & PARODD))
591 		cval |= UART_LCR_EPAR;
592 	if (cflag & CMSPAR)
593 		cval |= UART_LCR_SPAR;
594 
595 	info->FCR = 0;
596 	if (info->board->must_hwid) {
597 		info->FCR |= UART_FCR_ENABLE_FIFO |
598 			MOXA_MUST_FCR_GDA_MODE_ENABLE;
599 		mxser_set_must_fifo_value(info);
600 	} else if (info->type != PORT_8250 && info->type != PORT_16450) {
601 		info->FCR |= UART_FCR_ENABLE_FIFO;
602 		switch (info->rx_high_water) {
603 		case 1:
604 			info->FCR |= UART_FCR_TRIGGER_1;
605 			break;
606 		case 4:
607 			info->FCR |= UART_FCR_TRIGGER_4;
608 			break;
609 		case 8:
610 			info->FCR |= UART_FCR_TRIGGER_8;
611 			break;
612 		default:
613 			info->FCR |= UART_FCR_TRIGGER_14;
614 			break;
615 		}
616 	}
617 
618 	/* CTS flow control flag and modem status interrupts */
619 	info->IER &= ~UART_IER_MSI;
620 	info->MCR &= ~UART_MCR_AFE;
621 	tty_port_set_cts_flow(&info->port, cflag & CRTSCTS);
622 	if (cflag & CRTSCTS) {
623 		info->IER |= UART_IER_MSI;
624 		if (mxser_16550A_or_MUST(info)) {
625 			info->MCR |= UART_MCR_AFE;
626 		} else {
627 			mxser_handle_cts(tty, info,
628 					inb(info->ioaddr + UART_MSR));
629 		}
630 	}
631 	outb(info->MCR, info->ioaddr + UART_MCR);
632 	tty_port_set_check_carrier(&info->port, ~cflag & CLOCAL);
633 	if (~cflag & CLOCAL)
634 		info->IER |= UART_IER_MSI;
635 	outb(info->IER, info->ioaddr + UART_IER);
636 
637 	/*
638 	 * Set up parity check flag
639 	 */
640 	info->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
641 	if (I_INPCK(tty))
642 		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
643 	if (I_BRKINT(tty) || I_PARMRK(tty))
644 		info->read_status_mask |= UART_LSR_BI;
645 
646 	info->ignore_status_mask = 0;
647 
648 	if (I_IGNBRK(tty)) {
649 		info->ignore_status_mask |= UART_LSR_BI;
650 		info->read_status_mask |= UART_LSR_BI;
651 		/*
652 		 * If we're ignore parity and break indicators, ignore
653 		 * overruns too.  (For real raw support).
654 		 */
655 		if (I_IGNPAR(tty)) {
656 			info->ignore_status_mask |=
657 						UART_LSR_OE |
658 						UART_LSR_PE |
659 						UART_LSR_FE;
660 			info->read_status_mask |=
661 						UART_LSR_OE |
662 						UART_LSR_PE |
663 						UART_LSR_FE;
664 		}
665 	}
666 	if (info->board->must_hwid) {
667 		mxser_set_must_xon1_value(info->ioaddr, START_CHAR(tty));
668 		mxser_set_must_xoff1_value(info->ioaddr, STOP_CHAR(tty));
669 		mxser_must_set_rx_sw_flow_control(info->ioaddr, I_IXON(tty));
670 		mxser_must_set_tx_sw_flow_control(info->ioaddr, I_IXOFF(tty));
671 	}
672 
673 
674 	outb(info->FCR, info->ioaddr + UART_FCR);
675 	outb(cval, info->ioaddr + UART_LCR);
676 }
677 
678 static u8 mxser_check_modem_status(struct tty_struct *tty,
679 				struct mxser_port *port)
680 {
681 	u8 msr = inb(port->ioaddr + UART_MSR);
682 
683 	if (!(msr & UART_MSR_ANY_DELTA))
684 		return msr;
685 
686 	/* update input line counters */
687 	if (msr & UART_MSR_TERI)
688 		port->icount.rng++;
689 	if (msr & UART_MSR_DDSR)
690 		port->icount.dsr++;
691 	if (msr & UART_MSR_DDCD)
692 		port->icount.dcd++;
693 	if (msr & UART_MSR_DCTS)
694 		port->icount.cts++;
695 	wake_up_interruptible(&port->port.delta_msr_wait);
696 
697 	if (tty_port_check_carrier(&port->port) && (msr & UART_MSR_DDCD)) {
698 		if (msr & UART_MSR_DCD)
699 			wake_up_interruptible(&port->port.open_wait);
700 	}
701 
702 	if (tty_port_cts_enabled(&port->port))
703 		mxser_handle_cts(tty, port, msr);
704 
705 	return msr;
706 }
707 
708 static void mxser_disable_and_clear_FIFO(struct mxser_port *info)
709 {
710 	u8 fcr = UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT;
711 
712 	if (info->board->must_hwid)
713 		fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
714 
715 	outb(fcr, info->ioaddr + UART_FCR);
716 }
717 
718 static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
719 {
720 	struct mxser_port *info = container_of(port, struct mxser_port, port);
721 	unsigned long flags;
722 	int ret;
723 
724 	ret = tty_port_alloc_xmit_buf(port);
725 	if (ret < 0)
726 		return ret;
727 
728 	spin_lock_irqsave(&info->slock, flags);
729 
730 	if (!info->type) {
731 		set_bit(TTY_IO_ERROR, &tty->flags);
732 		spin_unlock_irqrestore(&info->slock, flags);
733 		ret = 0;
734 		goto err_free_xmit;
735 	}
736 
737 	/*
738 	 * Clear the FIFO buffers and disable them
739 	 * (they will be reenabled in mxser_change_speed())
740 	 */
741 	mxser_disable_and_clear_FIFO(info);
742 
743 	/*
744 	 * At this point there's no way the LSR could still be 0xFF;
745 	 * if it is, then bail out, because there's likely no UART
746 	 * here.
747 	 */
748 	if (inb(info->ioaddr + UART_LSR) == 0xff) {
749 		spin_unlock_irqrestore(&info->slock, flags);
750 		if (capable(CAP_SYS_ADMIN)) {
751 			set_bit(TTY_IO_ERROR, &tty->flags);
752 			return 0;
753 		}
754 
755 		ret = -ENODEV;
756 		goto err_free_xmit;
757 	}
758 
759 	/*
760 	 * Clear the interrupt registers.
761 	 */
762 	(void) inb(info->ioaddr + UART_LSR);
763 	(void) inb(info->ioaddr + UART_RX);
764 	(void) inb(info->ioaddr + UART_IIR);
765 	(void) inb(info->ioaddr + UART_MSR);
766 
767 	/*
768 	 * Now, initialize the UART
769 	 */
770 	outb(UART_LCR_WLEN8, info->ioaddr + UART_LCR);	/* reset DLAB */
771 	info->MCR = UART_MCR_DTR | UART_MCR_RTS;
772 	outb(info->MCR, info->ioaddr + UART_MCR);
773 
774 	/*
775 	 * Finally, enable interrupts
776 	 */
777 	info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
778 
779 	if (info->board->must_hwid)
780 		info->IER |= MOXA_MUST_IER_EGDAI;
781 	outb(info->IER, info->ioaddr + UART_IER);	/* enable interrupts */
782 
783 	/*
784 	 * And clear the interrupt registers again for luck.
785 	 */
786 	(void) inb(info->ioaddr + UART_LSR);
787 	(void) inb(info->ioaddr + UART_RX);
788 	(void) inb(info->ioaddr + UART_IIR);
789 	(void) inb(info->ioaddr + UART_MSR);
790 
791 	clear_bit(TTY_IO_ERROR, &tty->flags);
792 	kfifo_reset(&port->xmit_fifo);
793 
794 	/*
795 	 * and set the speed of the serial port
796 	 */
797 	mxser_change_speed(tty, NULL);
798 	spin_unlock_irqrestore(&info->slock, flags);
799 
800 	return 0;
801 err_free_xmit:
802 	tty_port_free_xmit_buf(port);
803 	return ret;
804 }
805 
806 /*
807  * To stop accepting input, we disable the receive line status interrupts, and
808  * tell the interrupt driver to stop checking the data ready bit in the line
809  * status register.
810  */
811 static void mxser_stop_rx(struct mxser_port *info)
812 {
813 	info->IER &= ~UART_IER_RLSI;
814 	if (info->board->must_hwid)
815 		info->IER &= ~MOXA_MUST_RECV_ISR;
816 
817 	outb(info->IER, info->ioaddr + UART_IER);
818 }
819 
820 /*
821  * This routine will shutdown a serial port
822  */
823 static void mxser_shutdown_port(struct tty_port *port)
824 {
825 	struct mxser_port *info = container_of(port, struct mxser_port, port);
826 
827 	scoped_guard(spinlock_irqsave, &info->slock) {
828 		mxser_stop_rx(info);
829 
830 		/*
831 		 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
832 		 * here so the queue might never be waken up
833 		 */
834 		wake_up_interruptible(&info->port.delta_msr_wait);
835 
836 		info->IER = 0;
837 		outb(0x00, info->ioaddr + UART_IER);
838 
839 		/* clear Rx/Tx FIFO's */
840 		mxser_disable_and_clear_FIFO(info);
841 
842 		/* read data port to reset things */
843 		(void)inb(info->ioaddr + UART_RX);
844 
845 		if (info->board->must_hwid)
846 			mxser_must_no_sw_flow_control(info->ioaddr);
847 	}
848 
849 	/* make sure ISR is not running while we free the buffer */
850 	synchronize_irq(info->board->irq);
851 
852 	tty_port_free_xmit_buf(port);
853 }
854 
855 /*
856  * This routine is called whenever a serial port is opened.  It
857  * enables interrupts for a serial port, linking in its async structure into
858  * the IRQ chain.   It also performs the serial-specific
859  * initialization for the tty structure.
860  */
861 static int mxser_open(struct tty_struct *tty, struct file *filp)
862 {
863 	struct tty_port *tport = tty->port;
864 	struct mxser_port *port = container_of(tport, struct mxser_port, port);
865 
866 	tty->driver_data = port;
867 
868 	return tty_port_open(tport, tty, filp);
869 }
870 
871 static void mxser_flush_buffer(struct tty_struct *tty)
872 {
873 	struct mxser_port *info = tty->driver_data;
874 
875 	scoped_guard(spinlock_irqsave, &info->slock) {
876 		kfifo_reset(&info->port.xmit_fifo);
877 
878 		outb(info->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
879 		     info->ioaddr + UART_FCR);
880 	}
881 
882 	tty_wakeup(tty);
883 }
884 
885 static void mxser_close(struct tty_struct *tty, struct file *filp)
886 {
887 	tty_port_close(tty->port, tty, filp);
888 }
889 
890 static ssize_t mxser_write(struct tty_struct *tty, const u8 *buf, size_t count)
891 {
892 	struct mxser_port *info = tty->driver_data;
893 	size_t written;
894 	bool is_empty;
895 
896 	scoped_guard(spinlock_irqsave, &info->slock) {
897 		written = kfifo_in(&info->port.xmit_fifo, buf, count);
898 		is_empty = kfifo_is_empty(&info->port.xmit_fifo);
899 	}
900 
901 	if (!is_empty && !tty->flow.stopped)
902 		if (!tty->hw_stopped || mxser_16550A_or_MUST(info))
903 			mxser_start_tx(info);
904 
905 	return written;
906 }
907 
908 static int mxser_put_char(struct tty_struct *tty, u8 ch)
909 {
910 	struct mxser_port *info = tty->driver_data;
911 
912 	guard(spinlock_irqsave)(&info->slock);
913 	return kfifo_put(&info->port.xmit_fifo, ch);
914 }
915 
916 
917 static void mxser_flush_chars(struct tty_struct *tty)
918 {
919 	struct mxser_port *info = tty->driver_data;
920 
921 	if (kfifo_is_empty(&info->port.xmit_fifo) || tty->flow.stopped ||
922 			(tty->hw_stopped && !mxser_16550A_or_MUST(info)))
923 		return;
924 
925 	mxser_start_tx(info);
926 }
927 
928 static unsigned int mxser_write_room(struct tty_struct *tty)
929 {
930 	struct mxser_port *info = tty->driver_data;
931 
932 	return kfifo_avail(&info->port.xmit_fifo);
933 }
934 
935 static unsigned int mxser_chars_in_buffer(struct tty_struct *tty)
936 {
937 	struct mxser_port *info = tty->driver_data;
938 
939 	return kfifo_len(&info->port.xmit_fifo);
940 }
941 
942 /*
943  * ------------------------------------------------------------
944  * friends of mxser_ioctl()
945  * ------------------------------------------------------------
946  */
947 static int mxser_get_serial_info(struct tty_struct *tty,
948 		struct serial_struct *ss)
949 {
950 	struct mxser_port *info = tty->driver_data;
951 	struct tty_port *port = &info->port;
952 	unsigned int closing_wait, close_delay;
953 
954 	guard(mutex)(&port->mutex);
955 
956 	close_delay = jiffies_to_msecs(info->port.close_delay) / 10;
957 	closing_wait = info->port.closing_wait;
958 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
959 		closing_wait = jiffies_to_msecs(closing_wait) / 10;
960 
961 	ss->type = info->type;
962 	ss->line = tty->index;
963 	ss->port = info->ioaddr;
964 	ss->irq = info->board->irq;
965 	ss->flags = info->port.flags;
966 	ss->baud_base = MXSER_BAUD_BASE;
967 	ss->close_delay = close_delay;
968 	ss->closing_wait = closing_wait;
969 	ss->custom_divisor = MXSER_CUSTOM_DIVISOR;
970 
971 	return 0;
972 }
973 
974 static int mxser_set_serial_info(struct tty_struct *tty,
975 		struct serial_struct *ss)
976 {
977 	struct mxser_port *info = tty->driver_data;
978 	struct tty_port *port = &info->port;
979 	speed_t baud;
980 	unsigned int old_speed, close_delay, closing_wait;
981 
982 	if (tty_io_error(tty))
983 		return -EIO;
984 
985 	guard(mutex)(&port->mutex);
986 
987 	if (ss->irq != info->board->irq || ss->port != info->ioaddr)
988 		return -EINVAL;
989 
990 	old_speed = port->flags & ASYNC_SPD_MASK;
991 
992 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
993 	closing_wait = ss->closing_wait;
994 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
995 		closing_wait = msecs_to_jiffies(closing_wait * 10);
996 
997 	if (!capable(CAP_SYS_ADMIN)) {
998 		if ((ss->baud_base != MXSER_BAUD_BASE) ||
999 				(close_delay != port->close_delay) ||
1000 				(closing_wait != port->closing_wait) ||
1001 				((ss->flags & ~ASYNC_USR_MASK) != (port->flags & ~ASYNC_USR_MASK)))
1002 			return -EPERM;
1003 
1004 		port->flags = (port->flags & ~ASYNC_USR_MASK) |
1005 				(ss->flags & ASYNC_USR_MASK);
1006 	} else {
1007 		/*
1008 		 * OK, past this point, all the error checking has been done.
1009 		 * At this point, we start making changes.....
1010 		 */
1011 		port->flags = ((port->flags & ~ASYNC_FLAGS) |
1012 				(ss->flags & ASYNC_FLAGS));
1013 		port->close_delay = close_delay;
1014 		port->closing_wait = closing_wait;
1015 		if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST &&
1016 				(ss->baud_base != MXSER_BAUD_BASE ||
1017 				ss->custom_divisor !=
1018 				MXSER_CUSTOM_DIVISOR)) {
1019 			if (ss->custom_divisor == 0)
1020 				return -EINVAL;
1021 
1022 			baud = ss->baud_base / ss->custom_divisor;
1023 			tty_encode_baud_rate(tty, baud, baud);
1024 		}
1025 
1026 		info->type = ss->type;
1027 
1028 		mxser_process_txrx_fifo(info);
1029 	}
1030 
1031 	if (tty_port_initialized(port)) {
1032 		if (old_speed != (port->flags & ASYNC_SPD_MASK)) {
1033 			guard(spinlock_irqsave)(&info->slock);
1034 			mxser_change_speed(tty, NULL);
1035 		}
1036 
1037 		return 0;
1038 	}
1039 
1040 	int retval = mxser_activate(port, tty);
1041 	if (retval == 0)
1042 		tty_port_set_initialized(port, true);
1043 
1044 	return retval;
1045 }
1046 
1047 /*
1048  * mxser_get_lsr_info - get line status register info
1049  *
1050  * Purpose: Let user call ioctl() to get info when the UART physically
1051  *	    is emptied.  On bus types like RS485, the transmitter must
1052  *	    release the bus after transmitting. This must be done when
1053  *	    the transmit shift register is empty, not be done when the
1054  *	    transmit holding register is empty.  This functionality
1055  *	    allows an RS485 driver to be written in user space.
1056  */
1057 static int mxser_get_lsr_info(struct mxser_port *info,
1058 		unsigned int __user *value)
1059 {
1060 	unsigned int result;
1061 	u8 status;
1062 
1063 	scoped_guard(spinlock_irqsave, &info->slock)
1064 		status = inb(info->ioaddr + UART_LSR);
1065 	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
1066 	return put_user(result, value);
1067 }
1068 
1069 static int mxser_tiocmget(struct tty_struct *tty)
1070 {
1071 	struct mxser_port *info = tty->driver_data;
1072 	unsigned char control;
1073 	u8 msr;
1074 
1075 	if (tty_io_error(tty))
1076 		return -EIO;
1077 
1078 	scoped_guard(spinlock_irqsave, &info->slock) {
1079 		control = info->MCR;
1080 		msr = mxser_check_modem_status(tty, info);
1081 	}
1082 
1083 	return ((control & UART_MCR_RTS) ? TIOCM_RTS : 0) |
1084 		    ((control & UART_MCR_DTR) ? TIOCM_DTR : 0) |
1085 		    ((msr & UART_MSR_DCD) ? TIOCM_CAR : 0) |
1086 		    ((msr & UART_MSR_RI) ? TIOCM_RNG : 0) |
1087 		    ((msr & UART_MSR_DSR) ? TIOCM_DSR : 0) |
1088 		    ((msr & UART_MSR_CTS) ? TIOCM_CTS : 0);
1089 }
1090 
1091 static int mxser_tiocmset(struct tty_struct *tty,
1092 		unsigned int set, unsigned int clear)
1093 {
1094 	struct mxser_port *info = tty->driver_data;
1095 
1096 	if (tty_io_error(tty))
1097 		return -EIO;
1098 
1099 	guard(spinlock_irqsave)(&info->slock);
1100 
1101 	if (set & TIOCM_RTS)
1102 		info->MCR |= UART_MCR_RTS;
1103 	if (set & TIOCM_DTR)
1104 		info->MCR |= UART_MCR_DTR;
1105 
1106 	if (clear & TIOCM_RTS)
1107 		info->MCR &= ~UART_MCR_RTS;
1108 	if (clear & TIOCM_DTR)
1109 		info->MCR &= ~UART_MCR_DTR;
1110 
1111 	outb(info->MCR, info->ioaddr + UART_MCR);
1112 
1113 	return 0;
1114 }
1115 
1116 static int mxser_cflags_changed(struct mxser_port *info, unsigned long arg,
1117 		struct async_icount *cprev)
1118 {
1119 	struct async_icount cnow;
1120 	int ret;
1121 
1122 	/* atomic copy */
1123 	scoped_guard(spinlock_irqsave, &info->slock)
1124 		cnow = info->icount;
1125 
1126 	ret =	((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
1127 		((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
1128 		((arg & TIOCM_CD)  && (cnow.dcd != cprev->dcd)) ||
1129 		((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
1130 
1131 	*cprev = cnow;
1132 
1133 	return ret;
1134 }
1135 
1136 /* We should likely switch to TIOCGRS485/TIOCSRS485. */
1137 static int mxser_ioctl_op_mode(struct mxser_port *port, int index, bool set,
1138 		int __user *u_opmode)
1139 {
1140 	int opmode, p = index % 4;
1141 	int shiftbit = p * 2;
1142 	u8 val;
1143 
1144 	if (port->board->must_hwid != MOXA_MUST_MU860_HWID)
1145 		return -EFAULT;
1146 
1147 	if (set) {
1148 		if (get_user(opmode, u_opmode))
1149 			return -EFAULT;
1150 
1151 		if (opmode & ~OP_MODE_MASK)
1152 			return -EINVAL;
1153 
1154 		guard(spinlock_irq)(&port->slock);
1155 		val = inb(port->opmode_ioaddr);
1156 		val &= ~(OP_MODE_MASK << shiftbit);
1157 		val |= (opmode << shiftbit);
1158 		outb(val, port->opmode_ioaddr);
1159 
1160 		return 0;
1161 	}
1162 
1163 	scoped_guard(spinlock_irq, &port->slock)
1164 		opmode = inb(port->opmode_ioaddr) >> shiftbit;
1165 
1166 	return put_user(opmode & OP_MODE_MASK, u_opmode);
1167 }
1168 
1169 static int mxser_ioctl(struct tty_struct *tty,
1170 		unsigned int cmd, unsigned long arg)
1171 {
1172 	struct mxser_port *info = tty->driver_data;
1173 	struct async_icount cnow;
1174 	void __user *argp = (void __user *)arg;
1175 
1176 	if (cmd == MOXA_SET_OP_MODE || cmd == MOXA_GET_OP_MODE)
1177 		return mxser_ioctl_op_mode(info, tty->index,
1178 				cmd == MOXA_SET_OP_MODE, argp);
1179 
1180 	if (cmd != TIOCMIWAIT && tty_io_error(tty))
1181 		return -EIO;
1182 
1183 	switch (cmd) {
1184 	case TIOCSERGETLSR:	/* Get line status register */
1185 		return  mxser_get_lsr_info(info, argp);
1186 		/*
1187 		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1188 		 * - mask passed in arg for lines of interest
1189 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1190 		 * Caller should use TIOCGICOUNT to see which one it was
1191 		 */
1192 	case TIOCMIWAIT:
1193 		/* note the counters on entry */
1194 		scoped_guard(spinlock_irqsave, &info->slock)
1195 			cnow = info->icount;
1196 
1197 		return wait_event_interruptible(info->port.delta_msr_wait,
1198 				mxser_cflags_changed(info, arg, &cnow));
1199 	default:
1200 		return -ENOIOCTLCMD;
1201 	}
1202 	return 0;
1203 }
1204 
1205 	/*
1206 	 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1207 	 * Return: write counters to the user passed counter struct
1208 	 * NB: both 1->0 and 0->1 transitions are counted except for
1209 	 *     RI where only 0->1 is counted.
1210 	 */
1211 
1212 static int mxser_get_icount(struct tty_struct *tty,
1213 		struct serial_icounter_struct *icount)
1214 
1215 {
1216 	struct mxser_port *info = tty->driver_data;
1217 	struct async_icount cnow;
1218 
1219 	scoped_guard(spinlock_irqsave, &info->slock)
1220 		cnow = info->icount;
1221 
1222 	icount->frame = cnow.frame;
1223 	icount->brk = cnow.brk;
1224 	icount->overrun = cnow.overrun;
1225 	icount->buf_overrun = cnow.buf_overrun;
1226 	icount->parity = cnow.parity;
1227 	icount->rx = cnow.rx;
1228 	icount->tx = cnow.tx;
1229 	icount->cts = cnow.cts;
1230 	icount->dsr = cnow.dsr;
1231 	icount->rng = cnow.rng;
1232 	icount->dcd = cnow.dcd;
1233 	return 0;
1234 }
1235 
1236 /*
1237  * This routine is called by the upper-layer tty layer to signal that
1238  * incoming characters should be throttled.
1239  */
1240 static void mxser_throttle(struct tty_struct *tty)
1241 {
1242 	struct mxser_port *info = tty->driver_data;
1243 
1244 	if (I_IXOFF(tty)) {
1245 		if (info->board->must_hwid) {
1246 			info->IER &= ~MOXA_MUST_RECV_ISR;
1247 			outb(info->IER, info->ioaddr + UART_IER);
1248 		} else {
1249 			info->x_char = STOP_CHAR(tty);
1250 			outb(0, info->ioaddr + UART_IER);
1251 			info->IER |= UART_IER_THRI;
1252 			outb(info->IER, info->ioaddr + UART_IER);
1253 		}
1254 	}
1255 
1256 	if (C_CRTSCTS(tty)) {
1257 		info->MCR &= ~UART_MCR_RTS;
1258 		outb(info->MCR, info->ioaddr + UART_MCR);
1259 	}
1260 }
1261 
1262 static void mxser_unthrottle(struct tty_struct *tty)
1263 {
1264 	struct mxser_port *info = tty->driver_data;
1265 
1266 	/* startrx */
1267 	if (I_IXOFF(tty)) {
1268 		if (info->x_char)
1269 			info->x_char = 0;
1270 		else {
1271 			if (info->board->must_hwid) {
1272 				info->IER |= MOXA_MUST_RECV_ISR;
1273 				outb(info->IER, info->ioaddr + UART_IER);
1274 			} else {
1275 				info->x_char = START_CHAR(tty);
1276 				outb(0, info->ioaddr + UART_IER);
1277 				info->IER |= UART_IER_THRI;
1278 				outb(info->IER, info->ioaddr + UART_IER);
1279 			}
1280 		}
1281 	}
1282 
1283 	if (C_CRTSCTS(tty)) {
1284 		info->MCR |= UART_MCR_RTS;
1285 		outb(info->MCR, info->ioaddr + UART_MCR);
1286 	}
1287 }
1288 
1289 /*
1290  * mxser_stop() and mxser_start()
1291  *
1292  * This routines are called before setting or resetting tty->flow.stopped.
1293  * They enable or disable transmitter interrupts, as necessary.
1294  */
1295 static void mxser_stop(struct tty_struct *tty)
1296 {
1297 	struct mxser_port *info = tty->driver_data;
1298 
1299 	guard(spinlock_irqsave)(&info->slock);
1300 	if (info->IER & UART_IER_THRI)
1301 		__mxser_stop_tx(info);
1302 }
1303 
1304 static void mxser_start(struct tty_struct *tty)
1305 {
1306 	struct mxser_port *info = tty->driver_data;
1307 
1308 	guard(spinlock_irqsave)(&info->slock);
1309 	if (!kfifo_is_empty(&info->port.xmit_fifo))
1310 		__mxser_start_tx(info);
1311 }
1312 
1313 static void mxser_set_termios(struct tty_struct *tty,
1314 			      const struct ktermios *old_termios)
1315 {
1316 	struct mxser_port *info = tty->driver_data;
1317 
1318 	scoped_guard(spinlock_irqsave, &info->slock)
1319 		mxser_change_speed(tty, old_termios);
1320 
1321 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
1322 		tty->hw_stopped = false;
1323 		mxser_start(tty);
1324 	}
1325 
1326 	/* Handle sw stopped */
1327 	if ((old_termios->c_iflag & IXON) && !I_IXON(tty)) {
1328 		tty->flow.stopped = 0;
1329 
1330 		if (info->board->must_hwid) {
1331 			guard(spinlock_irqsave)(&info->slock);
1332 			mxser_must_set_rx_sw_flow_control(info->ioaddr, false);
1333 		}
1334 
1335 		mxser_start(tty);
1336 	}
1337 }
1338 
1339 static bool mxser_tx_empty(struct mxser_port *info)
1340 {
1341 	guard(spinlock_irqsave)(&info->slock);
1342 	return !(inb(info->ioaddr + UART_LSR) & UART_LSR_TEMT);
1343 }
1344 
1345 /*
1346  * mxser_wait_until_sent() --- wait until the transmitter is empty
1347  */
1348 static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
1349 {
1350 	struct mxser_port *info = tty->driver_data;
1351 	unsigned long expire, char_time;
1352 
1353 	if (info->type == PORT_UNKNOWN)
1354 		return;
1355 
1356 	if (info->xmit_fifo_size == 0)
1357 		return;		/* Just in case.... */
1358 
1359 	/*
1360 	 * Set the check interval to be 1/5 of the estimated time to
1361 	 * send a single character, and make it at least 1.  The check
1362 	 * interval should also be less than the timeout.
1363 	 *
1364 	 * Note: we have to use pretty tight timings here to satisfy
1365 	 * the NIST-PCTS.
1366 	 */
1367 	char_time = (info->timeout - HZ / 50) / info->xmit_fifo_size;
1368 	char_time = char_time / 5;
1369 	if (char_time == 0)
1370 		char_time = 1;
1371 	if (timeout && timeout < char_time)
1372 		char_time = timeout;
1373 
1374 	char_time = jiffies_to_msecs(char_time);
1375 
1376 	/*
1377 	 * If the transmitter hasn't cleared in twice the approximate
1378 	 * amount of time to send the entire FIFO, it probably won't
1379 	 * ever clear.  This assumes the UART isn't doing flow
1380 	 * control, which is currently the case.  Hence, if it ever
1381 	 * takes longer than info->timeout, this is probably due to a
1382 	 * UART bug of some kind.  So, we clamp the timeout parameter at
1383 	 * 2*info->timeout.
1384 	 */
1385 	if (!timeout || timeout > 2 * info->timeout)
1386 		timeout = 2 * info->timeout;
1387 
1388 	expire = jiffies + timeout;
1389 
1390 	while (mxser_tx_empty(info)) {
1391 		msleep_interruptible(char_time);
1392 		if (signal_pending(current))
1393 			break;
1394 		if (time_after(jiffies, expire))
1395 			break;
1396 	}
1397 }
1398 
1399 /*
1400  * This routine is called by tty_hangup() when a hangup is signaled.
1401  */
1402 static void mxser_hangup(struct tty_struct *tty)
1403 {
1404 	struct mxser_port *info = tty->driver_data;
1405 
1406 	mxser_flush_buffer(tty);
1407 	tty_port_hangup(&info->port);
1408 }
1409 
1410 /*
1411  * mxser_rs_break() --- routine which turns the break handling on or off
1412  */
1413 static int mxser_rs_break(struct tty_struct *tty, int break_state)
1414 {
1415 	struct mxser_port *info = tty->driver_data;
1416 	u8 lcr;
1417 
1418 	guard(spinlock_irqsave)(&info->slock);
1419 	lcr = inb(info->ioaddr + UART_LCR);
1420 	if (break_state == -1)
1421 		lcr |= UART_LCR_SBC;
1422 	else
1423 		lcr &= ~UART_LCR_SBC;
1424 	outb(lcr, info->ioaddr + UART_LCR);
1425 
1426 	return 0;
1427 }
1428 
1429 static bool mxser_receive_chars_new(struct mxser_port *port, u8 status)
1430 {
1431 	enum mxser_must_hwid hwid = port->board->must_hwid;
1432 	u8 gdl;
1433 
1434 	if (hwid == MOXA_OTHER_UART)
1435 		return false;
1436 	if (status & (UART_LSR_BRK_ERROR_BITS | MOXA_MUST_LSR_RERR))
1437 		return false;
1438 
1439 	gdl = inb(port->ioaddr + MOXA_MUST_GDL_REGISTER);
1440 	if (hwid == MOXA_MUST_MU150_HWID)
1441 		gdl &= MOXA_MUST_GDL_MASK;
1442 
1443 	while (gdl--) {
1444 		u8 ch = inb(port->ioaddr + UART_RX);
1445 		if (!tty_insert_flip_char(&port->port, ch, 0))
1446 			port->icount.buf_overrun++;
1447 	}
1448 
1449 	return true;
1450 }
1451 
1452 static u8 mxser_receive_chars_old(struct tty_struct *tty,
1453 		                struct mxser_port *port, u8 status)
1454 {
1455 	enum mxser_must_hwid hwid = port->board->must_hwid;
1456 	int ignored = 0;
1457 	int max = 256;
1458 	u8 ch;
1459 
1460 	do {
1461 		if (max-- < 0)
1462 			break;
1463 
1464 		ch = inb(port->ioaddr + UART_RX);
1465 		if (hwid && (status & UART_LSR_OE))
1466 			outb(port->FCR | UART_FCR_CLEAR_RCVR,
1467 					port->ioaddr + UART_FCR);
1468 		status &= port->read_status_mask;
1469 		if (status & port->ignore_status_mask) {
1470 			if (++ignored > 100)
1471 				break;
1472 		} else {
1473 			u8 flag = 0;
1474 			if (status & UART_LSR_BRK_ERROR_BITS) {
1475 				if (status & UART_LSR_BI) {
1476 					flag = TTY_BREAK;
1477 					port->icount.brk++;
1478 
1479 					if (port->port.flags & ASYNC_SAK)
1480 						do_SAK(tty);
1481 				} else if (status & UART_LSR_PE) {
1482 					flag = TTY_PARITY;
1483 					port->icount.parity++;
1484 				} else if (status & UART_LSR_FE) {
1485 					flag = TTY_FRAME;
1486 					port->icount.frame++;
1487 				} else if (status & UART_LSR_OE) {
1488 					flag = TTY_OVERRUN;
1489 					port->icount.overrun++;
1490 				}
1491 			}
1492 			if (!tty_insert_flip_char(&port->port, ch, flag)) {
1493 				port->icount.buf_overrun++;
1494 				break;
1495 			}
1496 		}
1497 
1498 		if (hwid)
1499 			break;
1500 
1501 		status = inb(port->ioaddr + UART_LSR);
1502 	} while (status & UART_LSR_DR);
1503 
1504 	return status;
1505 }
1506 
1507 static u8 mxser_receive_chars(struct tty_struct *tty,
1508 		struct mxser_port *port, u8 status)
1509 {
1510 	if (!mxser_receive_chars_new(port, status))
1511 		status = mxser_receive_chars_old(tty, port, status);
1512 
1513 	tty_flip_buffer_push(&port->port);
1514 
1515 	return status;
1516 }
1517 
1518 static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port)
1519 {
1520 	int count;
1521 
1522 	if (port->x_char) {
1523 		outb(port->x_char, port->ioaddr + UART_TX);
1524 		port->x_char = 0;
1525 		port->icount.tx++;
1526 		return;
1527 	}
1528 
1529 	if (kfifo_is_empty(&port->port.xmit_fifo) || tty->flow.stopped ||
1530 			(tty->hw_stopped && !mxser_16550A_or_MUST(port))) {
1531 		__mxser_stop_tx(port);
1532 		return;
1533 	}
1534 
1535 	count = port->xmit_fifo_size;
1536 	do {
1537 		u8 c;
1538 
1539 		if (!kfifo_get(&port->port.xmit_fifo, &c))
1540 			break;
1541 
1542 		outb(c, port->ioaddr + UART_TX);
1543 		port->icount.tx++;
1544 	} while (--count > 0);
1545 
1546 	if (kfifo_len(&port->port.xmit_fifo) < WAKEUP_CHARS)
1547 		tty_wakeup(tty);
1548 
1549 	if (kfifo_is_empty(&port->port.xmit_fifo))
1550 		__mxser_stop_tx(port);
1551 }
1552 
1553 static bool mxser_port_isr(struct mxser_port *port)
1554 {
1555 	u8 iir, status;
1556 
1557 	iir = inb(port->ioaddr + UART_IIR);
1558 	if (iir & UART_IIR_NO_INT)
1559 		return true;
1560 
1561 	iir &= MOXA_MUST_IIR_MASK;
1562 
1563 	scoped_guard(tty_port_tty, &port->port) {
1564 		struct tty_struct *tty = scoped_tty();
1565 
1566 		status = inb(port->ioaddr + UART_LSR);
1567 
1568 		if (port->board->must_hwid) {
1569 			if (iir == MOXA_MUST_IIR_GDA ||
1570 			    iir == MOXA_MUST_IIR_RDA ||
1571 			    iir == MOXA_MUST_IIR_RTO ||
1572 			    iir == MOXA_MUST_IIR_LSR)
1573 				status = mxser_receive_chars(tty, port, status);
1574 		} else {
1575 			status &= port->read_status_mask;
1576 			if (status & UART_LSR_DR)
1577 				status = mxser_receive_chars(tty, port, status);
1578 		}
1579 
1580 		mxser_check_modem_status(tty, port);
1581 
1582 		if (port->board->must_hwid) {
1583 			if (iir == 0x02 && (status & UART_LSR_THRE))
1584 				mxser_transmit_chars(tty, port);
1585 		} else {
1586 			if (status & UART_LSR_THRE)
1587 				mxser_transmit_chars(tty, port);
1588 		}
1589 
1590 		return false;
1591 	}
1592 
1593 	status = inb(port->ioaddr + UART_LSR);
1594 	outb(port->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
1595 			port->ioaddr + UART_FCR);
1596 	inb(port->ioaddr + UART_MSR);
1597 
1598 	return true;
1599 }
1600 
1601 /*
1602  * This is the serial driver's generic interrupt routine
1603  */
1604 static irqreturn_t mxser_interrupt(int irq, void *dev_id)
1605 {
1606 	struct mxser_board *brd = dev_id;
1607 	struct mxser_port *port;
1608 	unsigned int int_cnt, pass_counter = 0;
1609 	unsigned int i, max = brd->nports;
1610 	int handled = IRQ_NONE;
1611 	u8 irqbits, bits, mask = BIT(max) - 1;
1612 
1613 	while (pass_counter++ < MXSER_ISR_PASS_LIMIT) {
1614 		irqbits = inb(brd->vector) & mask;
1615 		if (irqbits == mask)
1616 			break;
1617 
1618 		handled = IRQ_HANDLED;
1619 		for (i = 0, bits = 1; i < max; i++, irqbits |= bits, bits <<= 1) {
1620 			if (irqbits == mask)
1621 				break;
1622 			if (bits & irqbits)
1623 				continue;
1624 			port = &brd->ports[i];
1625 
1626 			int_cnt = 0;
1627 			guard(spinlock)(&port->slock);
1628 			do {
1629 				if (mxser_port_isr(port))
1630 					break;
1631 			} while (int_cnt++ < MXSER_ISR_PASS_LIMIT);
1632 		}
1633 	}
1634 
1635 	return handled;
1636 }
1637 
1638 static const struct tty_operations mxser_ops = {
1639 	.open = mxser_open,
1640 	.close = mxser_close,
1641 	.write = mxser_write,
1642 	.put_char = mxser_put_char,
1643 	.flush_chars = mxser_flush_chars,
1644 	.write_room = mxser_write_room,
1645 	.chars_in_buffer = mxser_chars_in_buffer,
1646 	.flush_buffer = mxser_flush_buffer,
1647 	.ioctl = mxser_ioctl,
1648 	.throttle = mxser_throttle,
1649 	.unthrottle = mxser_unthrottle,
1650 	.set_termios = mxser_set_termios,
1651 	.stop = mxser_stop,
1652 	.start = mxser_start,
1653 	.hangup = mxser_hangup,
1654 	.break_ctl = mxser_rs_break,
1655 	.wait_until_sent = mxser_wait_until_sent,
1656 	.tiocmget = mxser_tiocmget,
1657 	.tiocmset = mxser_tiocmset,
1658 	.set_serial = mxser_set_serial_info,
1659 	.get_serial = mxser_get_serial_info,
1660 	.get_icount = mxser_get_icount,
1661 };
1662 
1663 static const struct tty_port_operations mxser_port_ops = {
1664 	.carrier_raised = mxser_carrier_raised,
1665 	.dtr_rts = mxser_dtr_rts,
1666 	.activate = mxser_activate,
1667 	.shutdown = mxser_shutdown_port,
1668 };
1669 
1670 /*
1671  * The MOXA Smartio/Industio serial driver boot-time initialization code!
1672  */
1673 
1674 static void mxser_initbrd(struct mxser_board *brd, bool high_baud)
1675 {
1676 	struct mxser_port *info;
1677 	unsigned int i;
1678 	bool is_mu860;
1679 
1680 	brd->must_hwid = mxser_must_get_hwid(brd->ports[0].ioaddr);
1681 	is_mu860 = brd->must_hwid == MOXA_MUST_MU860_HWID;
1682 
1683 	for (i = 0; i < UART_INFO_NUM; i++) {
1684 		if (Gpci_uart_info[i].type == brd->must_hwid) {
1685 			brd->max_baud = Gpci_uart_info[i].max_baud;
1686 
1687 			/* exception....CP-102 */
1688 			if (high_baud)
1689 				brd->max_baud = 921600;
1690 			break;
1691 		}
1692 	}
1693 
1694 	if (is_mu860) {
1695 		/* set to RS232 mode by default */
1696 		outb(0, brd->vector + 4);
1697 		outb(0, brd->vector + 0x0c);
1698 	}
1699 
1700 	for (i = 0; i < brd->nports; i++) {
1701 		info = &brd->ports[i];
1702 		if (is_mu860) {
1703 			if (i < 4)
1704 				info->opmode_ioaddr = brd->vector + 4;
1705 			else
1706 				info->opmode_ioaddr = brd->vector + 0x0c;
1707 		}
1708 		tty_port_init(&info->port);
1709 		info->port.ops = &mxser_port_ops;
1710 		info->board = brd;
1711 
1712 		/* Enhance mode enabled here */
1713 		if (brd->must_hwid != MOXA_OTHER_UART)
1714 			mxser_must_set_enhance_mode(info->ioaddr, true);
1715 
1716 		info->type = PORT_16550A;
1717 
1718 		mxser_process_txrx_fifo(info);
1719 
1720 		spin_lock_init(&info->slock);
1721 
1722 		/* before set INT ISR, disable all int */
1723 		outb(inb(info->ioaddr + UART_IER) & 0xf0,
1724 			info->ioaddr + UART_IER);
1725 	}
1726 }
1727 
1728 static int mxser_probe(struct pci_dev *pdev,
1729 		const struct pci_device_id *ent)
1730 {
1731 	struct mxser_board *brd;
1732 	unsigned int i, base;
1733 	unsigned long ioaddress;
1734 	unsigned short nports = MXSER_NPORTS(ent->driver_data);
1735 	struct device *tty_dev;
1736 	int retval = -EINVAL;
1737 
1738 	i = find_first_zero_bit(mxser_boards, MXSER_BOARDS);
1739 	if (i >= MXSER_BOARDS) {
1740 		dev_err(&pdev->dev, "too many boards found (maximum %d), board "
1741 				"not configured\n", MXSER_BOARDS);
1742 		goto err;
1743 	}
1744 
1745 	brd = devm_kzalloc(&pdev->dev, struct_size(brd, ports, nports),
1746 			GFP_KERNEL);
1747 	if (!brd)
1748 		goto err;
1749 
1750 	brd->idx = i;
1751 	__set_bit(brd->idx, mxser_boards);
1752 	base = i * MXSER_PORTS_PER_BOARD;
1753 
1754 	retval = pcim_enable_device(pdev);
1755 	if (retval) {
1756 		dev_err(&pdev->dev, "PCI enable failed\n");
1757 		goto err_zero;
1758 	}
1759 
1760 	/* io address */
1761 	ioaddress = pci_resource_start(pdev, 2);
1762 	retval = pcim_request_region(pdev, 2, "mxser(IO)");
1763 	if (retval)
1764 		goto err_zero;
1765 
1766 	brd->nports = nports;
1767 	for (i = 0; i < nports; i++)
1768 		brd->ports[i].ioaddr = ioaddress + 8 * i;
1769 
1770 	/* vector */
1771 	ioaddress = pci_resource_start(pdev, 3);
1772 	retval = pcim_request_region(pdev, 3, "mxser(vector)");
1773 	if (retval)
1774 		goto err_zero;
1775 	brd->vector = ioaddress;
1776 
1777 	/* irq */
1778 	brd->irq = pdev->irq;
1779 
1780 	mxser_initbrd(brd, ent->driver_data & MXSER_HIGHBAUD);
1781 
1782 	retval = devm_request_irq(&pdev->dev, brd->irq, mxser_interrupt,
1783 			IRQF_SHARED, "mxser", brd);
1784 	if (retval) {
1785 		dev_err(&pdev->dev, "request irq failed");
1786 		goto err_relbrd;
1787 	}
1788 
1789 	for (i = 0; i < nports; i++) {
1790 		tty_dev = tty_port_register_device(&brd->ports[i].port,
1791 				mxvar_sdriver, base + i, &pdev->dev);
1792 		if (IS_ERR(tty_dev)) {
1793 			retval = PTR_ERR(tty_dev);
1794 			for (; i > 0; i--)
1795 				tty_unregister_device(mxvar_sdriver,
1796 					base + i - 1);
1797 			goto err_relbrd;
1798 		}
1799 	}
1800 
1801 	pci_set_drvdata(pdev, brd);
1802 
1803 	return 0;
1804 err_relbrd:
1805 	for (i = 0; i < nports; i++)
1806 		tty_port_destroy(&brd->ports[i].port);
1807 err_zero:
1808 	__clear_bit(brd->idx, mxser_boards);
1809 err:
1810 	return retval;
1811 }
1812 
1813 static void mxser_remove(struct pci_dev *pdev)
1814 {
1815 	struct mxser_board *brd = pci_get_drvdata(pdev);
1816 	unsigned int i, base = brd->idx * MXSER_PORTS_PER_BOARD;
1817 
1818 	for (i = 0; i < brd->nports; i++) {
1819 		tty_unregister_device(mxvar_sdriver, base + i);
1820 		tty_port_destroy(&brd->ports[i].port);
1821 	}
1822 
1823 	__clear_bit(brd->idx, mxser_boards);
1824 }
1825 
1826 static struct pci_driver mxser_driver = {
1827 	.name = "mxser",
1828 	.id_table = mxser_pcibrds,
1829 	.probe = mxser_probe,
1830 	.remove = mxser_remove
1831 };
1832 
1833 static int __init mxser_module_init(void)
1834 {
1835 	int retval;
1836 
1837 	mxvar_sdriver = tty_alloc_driver(MXSER_PORTS, TTY_DRIVER_REAL_RAW |
1838 			TTY_DRIVER_DYNAMIC_DEV);
1839 	if (IS_ERR(mxvar_sdriver))
1840 		return PTR_ERR(mxvar_sdriver);
1841 
1842 	/* Initialize the tty_driver structure */
1843 	mxvar_sdriver->name = "ttyMI";
1844 	mxvar_sdriver->major = ttymajor;
1845 	mxvar_sdriver->minor_start = 0;
1846 	mxvar_sdriver->type = TTY_DRIVER_TYPE_SERIAL;
1847 	mxvar_sdriver->subtype = SERIAL_TYPE_NORMAL;
1848 	mxvar_sdriver->init_termios = tty_std_termios;
1849 	mxvar_sdriver->init_termios.c_cflag = B9600|CS8|CREAD|HUPCL|CLOCAL;
1850 	tty_set_operations(mxvar_sdriver, &mxser_ops);
1851 
1852 	retval = tty_register_driver(mxvar_sdriver);
1853 	if (retval) {
1854 		printk(KERN_ERR "Couldn't install MOXA Smartio/Industio family "
1855 				"tty driver !\n");
1856 		goto err_put;
1857 	}
1858 
1859 	retval = pci_register_driver(&mxser_driver);
1860 	if (retval) {
1861 		printk(KERN_ERR "mxser: can't register pci driver\n");
1862 		goto err_unr;
1863 	}
1864 
1865 	return 0;
1866 err_unr:
1867 	tty_unregister_driver(mxvar_sdriver);
1868 err_put:
1869 	tty_driver_kref_put(mxvar_sdriver);
1870 	return retval;
1871 }
1872 
1873 static void __exit mxser_module_exit(void)
1874 {
1875 	pci_unregister_driver(&mxser_driver);
1876 	tty_unregister_driver(mxvar_sdriver);
1877 	tty_driver_kref_put(mxvar_sdriver);
1878 }
1879 
1880 module_init(mxser_module_init);
1881 module_exit(mxser_module_exit);
1882