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1/*
2 *
3 * Copyright (C) 2008 Christian Pellegrin <chripell@evolware.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 *
11 * Notes: the MAX3100 doesn't provide an interrupt on CTS so we have
12 * to use polling for flow control. TX empty IRQ is unusable, since
13 * writing conf clears FIFO buffer and we cannot have this interrupt
14 * always asking us for attention.
15 *
16 * Example platform data:
17
18 static struct plat_max3100 max3100_plat_data = {
19 .loopback = 0,
20 .crystal = 0,
21 .poll_time = 100,
22 };
23
24 static struct spi_board_info spi_board_info[] = {
25 {
26 .modalias = "max3100",
27 .platform_data = &max3100_plat_data,
28 .irq = IRQ_EINT12,
29 .max_speed_hz = 5*1000*1000,
30 .chip_select = 0,
31 },
32 };
33
34 * The initial minor number is 209 in the low-density serial port:
35 * mknod /dev/ttyMAX0 c 204 209
36 */
37
38#define MAX3100_MAJOR 204
39#define MAX3100_MINOR 209
40/* 4 MAX3100s should be enough for everyone */
41#define MAX_MAX3100 4
42
43#include <linux/delay.h>
44#include <linux/slab.h>
45#include <linux/device.h>
46#include <linux/serial_core.h>
47#include <linux/serial.h>
48#include <linux/spi/spi.h>
49#include <linux/freezer.h>
50
51#include <linux/serial_max3100.h>
52
53#define MAX3100_C (1<<14)
54#define MAX3100_D (0<<14)
55#define MAX3100_W (1<<15)
56#define MAX3100_RX (0<<15)
57
58#define MAX3100_WC (MAX3100_W | MAX3100_C)
59#define MAX3100_RC (MAX3100_RX | MAX3100_C)
60#define MAX3100_WD (MAX3100_W | MAX3100_D)
61#define MAX3100_RD (MAX3100_RX | MAX3100_D)
62#define MAX3100_CMD (3 << 14)
63
64#define MAX3100_T (1<<14)
65#define MAX3100_R (1<<15)
66
67#define MAX3100_FEN (1<<13)
68#define MAX3100_SHDN (1<<12)
69#define MAX3100_TM (1<<11)
70#define MAX3100_RM (1<<10)
71#define MAX3100_PM (1<<9)
72#define MAX3100_RAM (1<<8)
73#define MAX3100_IR (1<<7)
74#define MAX3100_ST (1<<6)
75#define MAX3100_PE (1<<5)
76#define MAX3100_L (1<<4)
77#define MAX3100_BAUD (0xf)
78
79#define MAX3100_TE (1<<10)
80#define MAX3100_RAFE (1<<10)
81#define MAX3100_RTS (1<<9)
82#define MAX3100_CTS (1<<9)
83#define MAX3100_PT (1<<8)
84#define MAX3100_DATA (0xff)
85
86#define MAX3100_RT (MAX3100_R | MAX3100_T)
87#define MAX3100_RTC (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE)
88
89/* the following simulate a status reg for ignore_status_mask */
90#define MAX3100_STATUS_PE 1
91#define MAX3100_STATUS_FE 2
92#define MAX3100_STATUS_OE 4
93
94struct max3100_port {
95 struct uart_port port;
96 struct spi_device *spi;
97
98 int cts; /* last CTS received for flow ctrl */
99 int tx_empty; /* last TX empty bit */
100
101 spinlock_t conf_lock; /* shared data */
102 int conf_commit; /* need to make changes */
103 int conf; /* configuration for the MAX31000
104 * (bits 0-7, bits 8-11 are irqs) */
105 int rts_commit; /* need to change rts */
106 int rts; /* rts status */
107 int baud; /* current baud rate */
108
109 int parity; /* keeps track if we should send parity */
110#define MAX3100_PARITY_ON 1
111#define MAX3100_PARITY_ODD 2
112#define MAX3100_7BIT 4
113 int rx_enabled; /* if we should rx chars */
114
115 int irq; /* irq assigned to the max3100 */
116
117 int minor; /* minor number */
118 int crystal; /* 1 if 3.6864Mhz crystal 0 for 1.8432 */
119 int loopback; /* 1 if we are in loopback mode */
120
121 /* for handling irqs: need workqueue since we do spi_sync */
122 struct workqueue_struct *workqueue;
123 struct work_struct work;
124 /* set to 1 to make the workhandler exit as soon as possible */
125 int force_end_work;
126 /* need to know we are suspending to avoid deadlock on workqueue */
127 int suspending;
128
129 /* hook for suspending MAX3100 via dedicated pin */
130 void (*max3100_hw_suspend) (int suspend);
131
132 /* poll time (in ms) for ctrl lines */
133 int poll_time;
134 /* and its timer */
135 struct timer_list timer;
136};
137
138static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
139static DEFINE_MUTEX(max3100s_lock); /* race on probe */
140
141static int max3100_do_parity(struct max3100_port *s, u16 c)
142{
143 int parity;
144
145 if (s->parity & MAX3100_PARITY_ODD)
146 parity = 1;
147 else
148 parity = 0;
149
150 if (s->parity & MAX3100_7BIT)
151 c &= 0x7f;
152 else
153 c &= 0xff;
154
155 parity = parity ^ (hweight8(c) & 1);
156 return parity;
157}
158
159static int max3100_check_parity(struct max3100_port *s, u16 c)
160{
161 return max3100_do_parity(s, c) == ((c >> 8) & 1);
162}
163
164static void max3100_calc_parity(struct max3100_port *s, u16 *c)
165{
166 if (s->parity & MAX3100_7BIT)
167 *c &= 0x7f;
168 else
169 *c &= 0xff;
170
171 if (s->parity & MAX3100_PARITY_ON)
172 *c |= max3100_do_parity(s, *c) << 8;
173}
174
175static void max3100_work(struct work_struct *w);
176
177static void max3100_dowork(struct max3100_port *s)
178{
179 if (!s->force_end_work && !work_pending(&s->work) &&
180 !freezing(current) && !s->suspending)
181 queue_work(s->workqueue, &s->work);
182}
183
184static void max3100_timeout(unsigned long data)
185{
186 struct max3100_port *s = (struct max3100_port *)data;
187
188 if (s->port.state) {
189 max3100_dowork(s);
190 mod_timer(&s->timer, jiffies + s->poll_time);
191 }
192}
193
194static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx)
195{
196 struct spi_message message;
197 u16 etx, erx;
198 int status;
199 struct spi_transfer tran = {
200 .tx_buf = &etx,
201 .rx_buf = &erx,
202 .len = 2,
203 };
204
205 etx = cpu_to_be16(tx);
206 spi_message_init(&message);
207 spi_message_add_tail(&tran, &message);
208 status = spi_sync(s->spi, &message);
209 if (status) {
210 dev_warn(&s->spi->dev, "error while calling spi_sync\n");
211 return -EIO;
212 }
213 *rx = be16_to_cpu(erx);
214 s->tx_empty = (*rx & MAX3100_T) > 0;
215 dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
216 return 0;
217}
218
219static int max3100_handlerx(struct max3100_port *s, u16 rx)
220{
221 unsigned int ch, flg, status = 0;
222 int ret = 0, cts;
223
224 if (rx & MAX3100_R && s->rx_enabled) {
225 dev_dbg(&s->spi->dev, "%s\n", __func__);
226 ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff);
227 if (rx & MAX3100_RAFE) {
228 s->port.icount.frame++;
229 flg = TTY_FRAME;
230 status |= MAX3100_STATUS_FE;
231 } else {
232 if (s->parity & MAX3100_PARITY_ON) {
233 if (max3100_check_parity(s, rx)) {
234 s->port.icount.rx++;
235 flg = TTY_NORMAL;
236 } else {
237 s->port.icount.parity++;
238 flg = TTY_PARITY;
239 status |= MAX3100_STATUS_PE;
240 }
241 } else {
242 s->port.icount.rx++;
243 flg = TTY_NORMAL;
244 }
245 }
246 uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg);
247 ret = 1;
248 }
249
250 cts = (rx & MAX3100_CTS) > 0;
251 if (s->cts != cts) {
252 s->cts = cts;
253 uart_handle_cts_change(&s->port, cts ? TIOCM_CTS : 0);
254 }
255
256 return ret;
257}
258
259static void max3100_work(struct work_struct *w)
260{
261 struct max3100_port *s = container_of(w, struct max3100_port, work);
262 int rxchars;
263 u16 tx, rx;
264 int conf, cconf, rts, crts;
265 struct circ_buf *xmit = &s->port.state->xmit;
266
267 dev_dbg(&s->spi->dev, "%s\n", __func__);
268
269 rxchars = 0;
270 do {
271 spin_lock(&s->conf_lock);
272 conf = s->conf;
273 cconf = s->conf_commit;
274 s->conf_commit = 0;
275 rts = s->rts;
276 crts = s->rts_commit;
277 s->rts_commit = 0;
278 spin_unlock(&s->conf_lock);
279 if (cconf)
280 max3100_sr(s, MAX3100_WC | conf, &rx);
281 if (crts) {
282 max3100_sr(s, MAX3100_WD | MAX3100_TE |
283 (s->rts ? MAX3100_RTS : 0), &rx);
284 rxchars += max3100_handlerx(s, rx);
285 }
286
287 max3100_sr(s, MAX3100_RD, &rx);
288 rxchars += max3100_handlerx(s, rx);
289
290 if (rx & MAX3100_T) {
291 tx = 0xffff;
292 if (s->port.x_char) {
293 tx = s->port.x_char;
294 s->port.icount.tx++;
295 s->port.x_char = 0;
296 } else if (!uart_circ_empty(xmit) &&
297 !uart_tx_stopped(&s->port)) {
298 tx = xmit->buf[xmit->tail];
299 xmit->tail = (xmit->tail + 1) &
300 (UART_XMIT_SIZE - 1);
301 s->port.icount.tx++;
302 }
303 if (tx != 0xffff) {
304 max3100_calc_parity(s, &tx);
305 tx |= MAX3100_WD | (s->rts ? MAX3100_RTS : 0);
306 max3100_sr(s, tx, &rx);
307 rxchars += max3100_handlerx(s, rx);
308 }
309 }
310
311 if (rxchars > 16 && s->port.state->port.tty != NULL) {
312 tty_flip_buffer_push(s->port.state->port.tty);
313 rxchars = 0;
314 }
315 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
316 uart_write_wakeup(&s->port);
317
318 } while (!s->force_end_work &&
319 !freezing(current) &&
320 ((rx & MAX3100_R) ||
321 (!uart_circ_empty(xmit) &&
322 !uart_tx_stopped(&s->port))));
323
324 if (rxchars > 0 && s->port.state->port.tty != NULL)
325 tty_flip_buffer_push(s->port.state->port.tty);
326}
327
328static irqreturn_t max3100_irq(int irqno, void *dev_id)
329{
330 struct max3100_port *s = dev_id;
331
332 dev_dbg(&s->spi->dev, "%s\n", __func__);
333
334 max3100_dowork(s);
335 return IRQ_HANDLED;
336}
337
338static void max3100_enable_ms(struct uart_port *port)
339{
340 struct max3100_port *s = container_of(port,
341 struct max3100_port,
342 port);
343
344 if (s->poll_time > 0)
345 mod_timer(&s->timer, jiffies);
346 dev_dbg(&s->spi->dev, "%s\n", __func__);
347}
348
349static void max3100_start_tx(struct uart_port *port)
350{
351 struct max3100_port *s = container_of(port,
352 struct max3100_port,
353 port);
354
355 dev_dbg(&s->spi->dev, "%s\n", __func__);
356
357 max3100_dowork(s);
358}
359
360static void max3100_stop_rx(struct uart_port *port)
361{
362 struct max3100_port *s = container_of(port,
363 struct max3100_port,
364 port);
365
366 dev_dbg(&s->spi->dev, "%s\n", __func__);
367
368 s->rx_enabled = 0;
369 spin_lock(&s->conf_lock);
370 s->conf &= ~MAX3100_RM;
371 s->conf_commit = 1;
372 spin_unlock(&s->conf_lock);
373 max3100_dowork(s);
374}
375
376static unsigned int max3100_tx_empty(struct uart_port *port)
377{
378 struct max3100_port *s = container_of(port,
379 struct max3100_port,
380 port);
381
382 dev_dbg(&s->spi->dev, "%s\n", __func__);
383
384 /* may not be truly up-to-date */
385 max3100_dowork(s);
386 return s->tx_empty;
387}
388
389static unsigned int max3100_get_mctrl(struct uart_port *port)
390{
391 struct max3100_port *s = container_of(port,
392 struct max3100_port,
393 port);
394
395 dev_dbg(&s->spi->dev, "%s\n", __func__);
396
397 /* may not be truly up-to-date */
398 max3100_dowork(s);
399 /* always assert DCD and DSR since these lines are not wired */
400 return (s->cts ? TIOCM_CTS : 0) | TIOCM_DSR | TIOCM_CAR;
401}
402
403static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl)
404{
405 struct max3100_port *s = container_of(port,
406 struct max3100_port,
407 port);
408 int rts;
409
410 dev_dbg(&s->spi->dev, "%s\n", __func__);
411
412 rts = (mctrl & TIOCM_RTS) > 0;
413
414 spin_lock(&s->conf_lock);
415 if (s->rts != rts) {
416 s->rts = rts;
417 s->rts_commit = 1;
418 max3100_dowork(s);
419 }
420 spin_unlock(&s->conf_lock);
421}
422
423static void
424max3100_set_termios(struct uart_port *port, struct ktermios *termios,
425 struct ktermios *old)
426{
427 struct max3100_port *s = container_of(port,
428 struct max3100_port,
429 port);
430 int baud = 0;
431 unsigned cflag;
432 u32 param_new, param_mask, parity = 0;
433
434 dev_dbg(&s->spi->dev, "%s\n", __func__);
435
436 cflag = termios->c_cflag;
437 param_new = 0;
438 param_mask = 0;
439
440 baud = tty_termios_baud_rate(termios);
441 param_new = s->conf & MAX3100_BAUD;
442 switch (baud) {
443 case 300:
444 if (s->crystal)
445 baud = s->baud;
446 else
447 param_new = 15;
448 break;
449 case 600:
450 param_new = 14 + s->crystal;
451 break;
452 case 1200:
453 param_new = 13 + s->crystal;
454 break;
455 case 2400:
456 param_new = 12 + s->crystal;
457 break;
458 case 4800:
459 param_new = 11 + s->crystal;
460 break;
461 case 9600:
462 param_new = 10 + s->crystal;
463 break;
464 case 19200:
465 param_new = 9 + s->crystal;
466 break;
467 case 38400:
468 param_new = 8 + s->crystal;
469 break;
470 case 57600:
471 param_new = 1 + s->crystal;
472 break;
473 case 115200:
474 param_new = 0 + s->crystal;
475 break;
476 case 230400:
477 if (s->crystal)
478 param_new = 0;
479 else
480 baud = s->baud;
481 break;
482 default:
483 baud = s->baud;
484 }
485 tty_termios_encode_baud_rate(termios, baud, baud);
486 s->baud = baud;
487 param_mask |= MAX3100_BAUD;
488
489 if ((cflag & CSIZE) == CS8) {
490 param_new &= ~MAX3100_L;
491 parity &= ~MAX3100_7BIT;
492 } else {
493 param_new |= MAX3100_L;
494 parity |= MAX3100_7BIT;
495 cflag = (cflag & ~CSIZE) | CS7;
496 }
497 param_mask |= MAX3100_L;
498
499 if (cflag & CSTOPB)
500 param_new |= MAX3100_ST;
501 else
502 param_new &= ~MAX3100_ST;
503 param_mask |= MAX3100_ST;
504
505 if (cflag & PARENB) {
506 param_new |= MAX3100_PE;
507 parity |= MAX3100_PARITY_ON;
508 } else {
509 param_new &= ~MAX3100_PE;
510 parity &= ~MAX3100_PARITY_ON;
511 }
512 param_mask |= MAX3100_PE;
513
514 if (cflag & PARODD)
515 parity |= MAX3100_PARITY_ODD;
516 else
517 parity &= ~MAX3100_PARITY_ODD;
518
519 /* mask termios capabilities we don't support */
520 cflag &= ~CMSPAR;
521 termios->c_cflag = cflag;
522
523 s->port.ignore_status_mask = 0;
524 if (termios->c_iflag & IGNPAR)
525 s->port.ignore_status_mask |=
526 MAX3100_STATUS_PE | MAX3100_STATUS_FE |
527 MAX3100_STATUS_OE;
528
529 /* we are sending char from a workqueue so enable */
530 s->port.state->port.tty->low_latency = 1;
531
532 if (s->poll_time > 0)
533 del_timer_sync(&s->timer);
534
535 uart_update_timeout(port, termios->c_cflag, baud);
536
537 spin_lock(&s->conf_lock);
538 s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
539 s->conf_commit = 1;
540 s->parity = parity;
541 spin_unlock(&s->conf_lock);
542 max3100_dowork(s);
543
544 if (UART_ENABLE_MS(&s->port, termios->c_cflag))
545 max3100_enable_ms(&s->port);
546}
547
548static void max3100_shutdown(struct uart_port *port)
549{
550 struct max3100_port *s = container_of(port,
551 struct max3100_port,
552 port);
553
554 dev_dbg(&s->spi->dev, "%s\n", __func__);
555
556 if (s->suspending)
557 return;
558
559 s->force_end_work = 1;
560
561 if (s->poll_time > 0)
562 del_timer_sync(&s->timer);
563
564 if (s->workqueue) {
565 flush_workqueue(s->workqueue);
566 destroy_workqueue(s->workqueue);
567 s->workqueue = NULL;
568 }
569 if (s->irq)
570 free_irq(s->irq, s);
571
572 /* set shutdown mode to save power */
573 if (s->max3100_hw_suspend)
574 s->max3100_hw_suspend(1);
575 else {
576 u16 tx, rx;
577
578 tx = MAX3100_WC | MAX3100_SHDN;
579 max3100_sr(s, tx, &rx);
580 }
581}
582
583static int max3100_startup(struct uart_port *port)
584{
585 struct max3100_port *s = container_of(port,
586 struct max3100_port,
587 port);
588 char b[12];
589
590 dev_dbg(&s->spi->dev, "%s\n", __func__);
591
592 s->conf = MAX3100_RM;
593 s->baud = s->crystal ? 230400 : 115200;
594 s->rx_enabled = 1;
595
596 if (s->suspending)
597 return 0;
598
599 s->force_end_work = 0;
600 s->parity = 0;
601 s->rts = 0;
602
603 sprintf(b, "max3100-%d", s->minor);
604 s->workqueue = create_freezable_workqueue(b);
605 if (!s->workqueue) {
606 dev_warn(&s->spi->dev, "cannot create workqueue\n");
607 return -EBUSY;
608 }
609 INIT_WORK(&s->work, max3100_work);
610
611 if (request_irq(s->irq, max3100_irq,
612 IRQF_TRIGGER_FALLING, "max3100", s) < 0) {
613 dev_warn(&s->spi->dev, "cannot allocate irq %d\n", s->irq);
614 s->irq = 0;
615 destroy_workqueue(s->workqueue);
616 s->workqueue = NULL;
617 return -EBUSY;
618 }
619
620 if (s->loopback) {
621 u16 tx, rx;
622 tx = 0x4001;
623 max3100_sr(s, tx, &rx);
624 }
625
626 if (s->max3100_hw_suspend)
627 s->max3100_hw_suspend(0);
628 s->conf_commit = 1;
629 max3100_dowork(s);
630 /* wait for clock to settle */
631 msleep(50);
632
633 max3100_enable_ms(&s->port);
634
635 return 0;
636}
637
638static const char *max3100_type(struct uart_port *port)
639{
640 struct max3100_port *s = container_of(port,
641 struct max3100_port,
642 port);
643
644 dev_dbg(&s->spi->dev, "%s\n", __func__);
645
646 return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL;
647}
648
649static void max3100_release_port(struct uart_port *port)
650{
651 struct max3100_port *s = container_of(port,
652 struct max3100_port,
653 port);
654
655 dev_dbg(&s->spi->dev, "%s\n", __func__);
656}
657
658static void max3100_config_port(struct uart_port *port, int flags)
659{
660 struct max3100_port *s = container_of(port,
661 struct max3100_port,
662 port);
663
664 dev_dbg(&s->spi->dev, "%s\n", __func__);
665
666 if (flags & UART_CONFIG_TYPE)
667 s->port.type = PORT_MAX3100;
668}
669
670static int max3100_verify_port(struct uart_port *port,
671 struct serial_struct *ser)
672{
673 struct max3100_port *s = container_of(port,
674 struct max3100_port,
675 port);
676 int ret = -EINVAL;
677
678 dev_dbg(&s->spi->dev, "%s\n", __func__);
679
680 if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100)
681 ret = 0;
682 return ret;
683}
684
685static void max3100_stop_tx(struct uart_port *port)
686{
687 struct max3100_port *s = container_of(port,
688 struct max3100_port,
689 port);
690
691 dev_dbg(&s->spi->dev, "%s\n", __func__);
692}
693
694static int max3100_request_port(struct uart_port *port)
695{
696 struct max3100_port *s = container_of(port,
697 struct max3100_port,
698 port);
699
700 dev_dbg(&s->spi->dev, "%s\n", __func__);
701 return 0;
702}
703
704static void max3100_break_ctl(struct uart_port *port, int break_state)
705{
706 struct max3100_port *s = container_of(port,
707 struct max3100_port,
708 port);
709
710 dev_dbg(&s->spi->dev, "%s\n", __func__);
711}
712
713static struct uart_ops max3100_ops = {
714 .tx_empty = max3100_tx_empty,
715 .set_mctrl = max3100_set_mctrl,
716 .get_mctrl = max3100_get_mctrl,
717 .stop_tx = max3100_stop_tx,
718 .start_tx = max3100_start_tx,
719 .stop_rx = max3100_stop_rx,
720 .enable_ms = max3100_enable_ms,
721 .break_ctl = max3100_break_ctl,
722 .startup = max3100_startup,
723 .shutdown = max3100_shutdown,
724 .set_termios = max3100_set_termios,
725 .type = max3100_type,
726 .release_port = max3100_release_port,
727 .request_port = max3100_request_port,
728 .config_port = max3100_config_port,
729 .verify_port = max3100_verify_port,
730};
731
732static struct uart_driver max3100_uart_driver = {
733 .owner = THIS_MODULE,
734 .driver_name = "ttyMAX",
735 .dev_name = "ttyMAX",
736 .major = MAX3100_MAJOR,
737 .minor = MAX3100_MINOR,
738 .nr = MAX_MAX3100,
739};
740static int uart_driver_registered;
741
742static int __devinit max3100_probe(struct spi_device *spi)
743{
744 int i, retval;
745 struct plat_max3100 *pdata;
746 u16 tx, rx;
747
748 mutex_lock(&max3100s_lock);
749
750 if (!uart_driver_registered) {
751 uart_driver_registered = 1;
752 retval = uart_register_driver(&max3100_uart_driver);
753 if (retval) {
754 printk(KERN_ERR "Couldn't register max3100 uart driver\n");
755 mutex_unlock(&max3100s_lock);
756 return retval;
757 }
758 }
759
760 for (i = 0; i < MAX_MAX3100; i++)
761 if (!max3100s[i])
762 break;
763 if (i == MAX_MAX3100) {
764 dev_warn(&spi->dev, "too many MAX3100 chips\n");
765 mutex_unlock(&max3100s_lock);
766 return -ENOMEM;
767 }
768
769 max3100s[i] = kzalloc(sizeof(struct max3100_port), GFP_KERNEL);
770 if (!max3100s[i]) {
771 dev_warn(&spi->dev,
772 "kmalloc for max3100 structure %d failed!\n", i);
773 mutex_unlock(&max3100s_lock);
774 return -ENOMEM;
775 }
776 max3100s[i]->spi = spi;
777 max3100s[i]->irq = spi->irq;
778 spin_lock_init(&max3100s[i]->conf_lock);
779 dev_set_drvdata(&spi->dev, max3100s[i]);
780 pdata = spi->dev.platform_data;
781 max3100s[i]->crystal = pdata->crystal;
782 max3100s[i]->loopback = pdata->loopback;
783 max3100s[i]->poll_time = pdata->poll_time * HZ / 1000;
784 if (pdata->poll_time > 0 && max3100s[i]->poll_time == 0)
785 max3100s[i]->poll_time = 1;
786 max3100s[i]->max3100_hw_suspend = pdata->max3100_hw_suspend;
787 max3100s[i]->minor = i;
788 init_timer(&max3100s[i]->timer);
789 max3100s[i]->timer.function = max3100_timeout;
790 max3100s[i]->timer.data = (unsigned long) max3100s[i];
791
792 dev_dbg(&spi->dev, "%s: adding port %d\n", __func__, i);
793 max3100s[i]->port.irq = max3100s[i]->irq;
794 max3100s[i]->port.uartclk = max3100s[i]->crystal ? 3686400 : 1843200;
795 max3100s[i]->port.fifosize = 16;
796 max3100s[i]->port.ops = &max3100_ops;
797 max3100s[i]->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
798 max3100s[i]->port.line = i;
799 max3100s[i]->port.type = PORT_MAX3100;
800 max3100s[i]->port.dev = &spi->dev;
801 retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port);
802 if (retval < 0)
803 dev_warn(&spi->dev,
804 "uart_add_one_port failed for line %d with error %d\n",
805 i, retval);
806
807 /* set shutdown mode to save power. Will be woken-up on open */
808 if (max3100s[i]->max3100_hw_suspend)
809 max3100s[i]->max3100_hw_suspend(1);
810 else {
811 tx = MAX3100_WC | MAX3100_SHDN;
812 max3100_sr(max3100s[i], tx, &rx);
813 }
814 mutex_unlock(&max3100s_lock);
815 return 0;
816}
817
818static int __devexit max3100_remove(struct spi_device *spi)
819{
820 struct max3100_port *s = dev_get_drvdata(&spi->dev);
821 int i;
822
823 mutex_lock(&max3100s_lock);
824
825 /* find out the index for the chip we are removing */
826 for (i = 0; i < MAX_MAX3100; i++)
827 if (max3100s[i] == s)
828 break;
829
830 dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i);
831 uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port);
832 kfree(max3100s[i]);
833 max3100s[i] = NULL;
834
835 /* check if this is the last chip we have */
836 for (i = 0; i < MAX_MAX3100; i++)
837 if (max3100s[i]) {
838 mutex_unlock(&max3100s_lock);
839 return 0;
840 }
841 pr_debug("removing max3100 driver\n");
842 uart_unregister_driver(&max3100_uart_driver);
843
844 mutex_unlock(&max3100s_lock);
845 return 0;
846}
847
848#ifdef CONFIG_PM
849
850static int max3100_suspend(struct spi_device *spi, pm_message_t state)
851{
852 struct max3100_port *s = dev_get_drvdata(&spi->dev);
853
854 dev_dbg(&s->spi->dev, "%s\n", __func__);
855
856 disable_irq(s->irq);
857
858 s->suspending = 1;
859 uart_suspend_port(&max3100_uart_driver, &s->port);
860
861 if (s->max3100_hw_suspend)
862 s->max3100_hw_suspend(1);
863 else {
864 /* no HW suspend, so do SW one */
865 u16 tx, rx;
866
867 tx = MAX3100_WC | MAX3100_SHDN;
868 max3100_sr(s, tx, &rx);
869 }
870 return 0;
871}
872
873static int max3100_resume(struct spi_device *spi)
874{
875 struct max3100_port *s = dev_get_drvdata(&spi->dev);
876
877 dev_dbg(&s->spi->dev, "%s\n", __func__);
878
879 if (s->max3100_hw_suspend)
880 s->max3100_hw_suspend(0);
881 uart_resume_port(&max3100_uart_driver, &s->port);
882 s->suspending = 0;
883
884 enable_irq(s->irq);
885
886 s->conf_commit = 1;
887 if (s->workqueue)
888 max3100_dowork(s);
889
890 return 0;
891}
892
893#else
894#define max3100_suspend NULL
895#define max3100_resume NULL
896#endif
897
898static struct spi_driver max3100_driver = {
899 .driver = {
900 .name = "max3100",
901 .bus = &spi_bus_type,
902 .owner = THIS_MODULE,
903 },
904
905 .probe = max3100_probe,
906 .remove = __devexit_p(max3100_remove),
907 .suspend = max3100_suspend,
908 .resume = max3100_resume,
909};
910
911static int __init max3100_init(void)
912{
913 return spi_register_driver(&max3100_driver);
914}
915module_init(max3100_init);
916
917static void __exit max3100_exit(void)
918{
919 spi_unregister_driver(&max3100_driver);
920}
921module_exit(max3100_exit);
922
923MODULE_DESCRIPTION("MAX3100 driver");
924MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
925MODULE_LICENSE("GPL");
926MODULE_ALIAS("spi:max3100");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2008 Christian Pellegrin <chripell@evolware.org>
4 *
5 * Notes: the MAX3100 doesn't provide an interrupt on CTS so we have
6 * to use polling for flow control. TX empty IRQ is unusable, since
7 * writing conf clears FIFO buffer and we cannot have this interrupt
8 * always asking us for attention.
9 *
10 * The initial minor number is 209 in the low-density serial port:
11 * mknod /dev/ttyMAX0 c 204 209
12 */
13
14#define MAX3100_MAJOR 204
15#define MAX3100_MINOR 209
16/* 4 MAX3100s should be enough for everyone */
17#define MAX_MAX3100 4
18
19#include <linux/container_of.h>
20#include <linux/delay.h>
21#include <linux/device.h>
22#include <linux/freezer.h>
23#include <linux/mod_devicetable.h>
24#include <linux/module.h>
25#include <linux/pm.h>
26#include <linux/property.h>
27#include <linux/serial_core.h>
28#include <linux/serial.h>
29#include <linux/slab.h>
30#include <linux/spi/spi.h>
31#include <linux/tty_flip.h>
32#include <linux/tty.h>
33#include <linux/types.h>
34
35#include <linux/unaligned.h>
36
37#define MAX3100_C (1<<14)
38#define MAX3100_D (0<<14)
39#define MAX3100_W (1<<15)
40#define MAX3100_RX (0<<15)
41
42#define MAX3100_WC (MAX3100_W | MAX3100_C)
43#define MAX3100_RC (MAX3100_RX | MAX3100_C)
44#define MAX3100_WD (MAX3100_W | MAX3100_D)
45#define MAX3100_RD (MAX3100_RX | MAX3100_D)
46#define MAX3100_CMD (3 << 14)
47
48#define MAX3100_T (1<<14)
49#define MAX3100_R (1<<15)
50
51#define MAX3100_FEN (1<<13)
52#define MAX3100_SHDN (1<<12)
53#define MAX3100_TM (1<<11)
54#define MAX3100_RM (1<<10)
55#define MAX3100_PM (1<<9)
56#define MAX3100_RAM (1<<8)
57#define MAX3100_IR (1<<7)
58#define MAX3100_ST (1<<6)
59#define MAX3100_PE (1<<5)
60#define MAX3100_L (1<<4)
61#define MAX3100_BAUD (0xf)
62
63#define MAX3100_TE (1<<10)
64#define MAX3100_RAFE (1<<10)
65#define MAX3100_RTS (1<<9)
66#define MAX3100_CTS (1<<9)
67#define MAX3100_PT (1<<8)
68#define MAX3100_DATA (0xff)
69
70#define MAX3100_RT (MAX3100_R | MAX3100_T)
71#define MAX3100_RTC (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE)
72
73/* the following simulate a status reg for ignore_status_mask */
74#define MAX3100_STATUS_PE 1
75#define MAX3100_STATUS_FE 2
76#define MAX3100_STATUS_OE 4
77
78struct max3100_port {
79 struct uart_port port;
80 struct spi_device *spi;
81
82 int cts; /* last CTS received for flow ctrl */
83 int tx_empty; /* last TX empty bit */
84
85 spinlock_t conf_lock; /* shared data */
86 int conf_commit; /* need to make changes */
87 int conf; /* configuration for the MAX31000
88 * (bits 0-7, bits 8-11 are irqs) */
89 int rts_commit; /* need to change rts */
90 int rts; /* rts status */
91 int baud; /* current baud rate */
92
93 int parity; /* keeps track if we should send parity */
94#define MAX3100_PARITY_ON 1
95#define MAX3100_PARITY_ODD 2
96#define MAX3100_7BIT 4
97 int rx_enabled; /* if we should rx chars */
98
99 int minor; /* minor number */
100 int loopback_commit; /* need to change loopback */
101 int loopback; /* 1 if we are in loopback mode */
102
103 /* for handling irqs: need workqueue since we do spi_sync */
104 struct workqueue_struct *workqueue;
105 struct work_struct work;
106 /* set to 1 to make the workhandler exit as soon as possible */
107 int force_end_work;
108 /* need to know we are suspending to avoid deadlock on workqueue */
109 int suspending;
110
111 struct timer_list timer;
112};
113
114static inline struct max3100_port *to_max3100_port(struct uart_port *port)
115{
116 return container_of(port, struct max3100_port, port);
117}
118
119static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
120static DEFINE_MUTEX(max3100s_lock); /* race on probe */
121
122static int max3100_do_parity(struct max3100_port *s, u16 c)
123{
124 int parity;
125
126 if (s->parity & MAX3100_PARITY_ODD)
127 parity = 1;
128 else
129 parity = 0;
130
131 if (s->parity & MAX3100_7BIT)
132 c &= 0x7f;
133 else
134 c &= 0xff;
135
136 parity = parity ^ (hweight8(c) & 1);
137 return parity;
138}
139
140static int max3100_check_parity(struct max3100_port *s, u16 c)
141{
142 return max3100_do_parity(s, c) == ((c >> 8) & 1);
143}
144
145static void max3100_calc_parity(struct max3100_port *s, u16 *c)
146{
147 if (s->parity & MAX3100_7BIT)
148 *c &= 0x7f;
149 else
150 *c &= 0xff;
151
152 if (s->parity & MAX3100_PARITY_ON)
153 *c |= max3100_do_parity(s, *c) << 8;
154}
155
156static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx)
157{
158 struct spi_message message;
159 __be16 etx, erx;
160 int status;
161 struct spi_transfer tran = {
162 .tx_buf = &etx,
163 .rx_buf = &erx,
164 .len = 2,
165 };
166
167 etx = cpu_to_be16(tx);
168 spi_message_init(&message);
169 spi_message_add_tail(&tran, &message);
170 status = spi_sync(s->spi, &message);
171 if (status) {
172 dev_warn(&s->spi->dev, "error while calling spi_sync\n");
173 return -EIO;
174 }
175 *rx = be16_to_cpu(erx);
176 s->tx_empty = (*rx & MAX3100_T) > 0;
177 dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
178 return 0;
179}
180
181static int max3100_handlerx_unlocked(struct max3100_port *s, u16 rx)
182{
183 unsigned int status = 0;
184 int ret = 0, cts;
185 u8 ch, flg;
186
187 if (rx & MAX3100_R && s->rx_enabled) {
188 dev_dbg(&s->spi->dev, "%s\n", __func__);
189 ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff);
190 if (rx & MAX3100_RAFE) {
191 s->port.icount.frame++;
192 flg = TTY_FRAME;
193 status |= MAX3100_STATUS_FE;
194 } else {
195 if (s->parity & MAX3100_PARITY_ON) {
196 if (max3100_check_parity(s, rx)) {
197 s->port.icount.rx++;
198 flg = TTY_NORMAL;
199 } else {
200 s->port.icount.parity++;
201 flg = TTY_PARITY;
202 status |= MAX3100_STATUS_PE;
203 }
204 } else {
205 s->port.icount.rx++;
206 flg = TTY_NORMAL;
207 }
208 }
209 uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg);
210 ret = 1;
211 }
212
213 cts = (rx & MAX3100_CTS) > 0;
214 if (s->cts != cts) {
215 s->cts = cts;
216 uart_handle_cts_change(&s->port, cts);
217 }
218
219 return ret;
220}
221
222static int max3100_handlerx(struct max3100_port *s, u16 rx)
223{
224 unsigned long flags;
225 int ret;
226
227 uart_port_lock_irqsave(&s->port, &flags);
228 ret = max3100_handlerx_unlocked(s, rx);
229 uart_port_unlock_irqrestore(&s->port, flags);
230 return ret;
231}
232
233static void max3100_work(struct work_struct *w)
234{
235 struct max3100_port *s = container_of(w, struct max3100_port, work);
236 struct tty_port *tport = &s->port.state->port;
237 unsigned char ch;
238 int conf, cconf, cloopback, crts;
239 int rxchars;
240 u16 tx, rx;
241
242 dev_dbg(&s->spi->dev, "%s\n", __func__);
243
244 rxchars = 0;
245 do {
246 spin_lock(&s->conf_lock);
247 conf = s->conf;
248 cconf = s->conf_commit;
249 s->conf_commit = 0;
250 cloopback = s->loopback_commit;
251 s->loopback_commit = 0;
252 crts = s->rts_commit;
253 s->rts_commit = 0;
254 spin_unlock(&s->conf_lock);
255 if (cconf)
256 max3100_sr(s, MAX3100_WC | conf, &rx);
257 if (cloopback)
258 max3100_sr(s, 0x4001, &rx);
259 if (crts) {
260 max3100_sr(s, MAX3100_WD | MAX3100_TE |
261 (s->rts ? MAX3100_RTS : 0), &rx);
262 rxchars += max3100_handlerx(s, rx);
263 }
264
265 max3100_sr(s, MAX3100_RD, &rx);
266 rxchars += max3100_handlerx(s, rx);
267
268 if (rx & MAX3100_T) {
269 tx = 0xffff;
270 if (s->port.x_char) {
271 tx = s->port.x_char;
272 s->port.icount.tx++;
273 s->port.x_char = 0;
274 } else if (!uart_tx_stopped(&s->port) &&
275 uart_fifo_get(&s->port, &ch)) {
276 tx = ch;
277 }
278 if (tx != 0xffff) {
279 max3100_calc_parity(s, &tx);
280 tx |= MAX3100_WD | (s->rts ? MAX3100_RTS : 0);
281 max3100_sr(s, tx, &rx);
282 rxchars += max3100_handlerx(s, rx);
283 }
284 }
285
286 if (rxchars > 16) {
287 tty_flip_buffer_push(&s->port.state->port);
288 rxchars = 0;
289 }
290 if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
291 uart_write_wakeup(&s->port);
292
293 } while (!s->force_end_work &&
294 !freezing(current) &&
295 ((rx & MAX3100_R) ||
296 (!kfifo_is_empty(&tport->xmit_fifo) &&
297 !uart_tx_stopped(&s->port))));
298
299 if (rxchars > 0)
300 tty_flip_buffer_push(&s->port.state->port);
301}
302
303static void max3100_dowork(struct max3100_port *s)
304{
305 if (!s->force_end_work && !freezing(current) && !s->suspending)
306 queue_work(s->workqueue, &s->work);
307}
308
309static void max3100_timeout(struct timer_list *t)
310{
311 struct max3100_port *s = from_timer(s, t, timer);
312
313 max3100_dowork(s);
314 mod_timer(&s->timer, jiffies + uart_poll_timeout(&s->port));
315}
316
317static irqreturn_t max3100_irq(int irqno, void *dev_id)
318{
319 struct max3100_port *s = dev_id;
320
321 dev_dbg(&s->spi->dev, "%s\n", __func__);
322
323 max3100_dowork(s);
324 return IRQ_HANDLED;
325}
326
327static void max3100_enable_ms(struct uart_port *port)
328{
329 struct max3100_port *s = to_max3100_port(port);
330
331 mod_timer(&s->timer, jiffies);
332 dev_dbg(&s->spi->dev, "%s\n", __func__);
333}
334
335static void max3100_start_tx(struct uart_port *port)
336{
337 struct max3100_port *s = to_max3100_port(port);
338
339 dev_dbg(&s->spi->dev, "%s\n", __func__);
340
341 max3100_dowork(s);
342}
343
344static void max3100_stop_rx(struct uart_port *port)
345{
346 struct max3100_port *s = to_max3100_port(port);
347
348 dev_dbg(&s->spi->dev, "%s\n", __func__);
349
350 s->rx_enabled = 0;
351 spin_lock(&s->conf_lock);
352 s->conf &= ~MAX3100_RM;
353 s->conf_commit = 1;
354 spin_unlock(&s->conf_lock);
355 max3100_dowork(s);
356}
357
358static unsigned int max3100_tx_empty(struct uart_port *port)
359{
360 struct max3100_port *s = to_max3100_port(port);
361
362 dev_dbg(&s->spi->dev, "%s\n", __func__);
363
364 /* may not be truly up-to-date */
365 max3100_dowork(s);
366 return s->tx_empty;
367}
368
369static unsigned int max3100_get_mctrl(struct uart_port *port)
370{
371 struct max3100_port *s = to_max3100_port(port);
372
373 dev_dbg(&s->spi->dev, "%s\n", __func__);
374
375 /* may not be truly up-to-date */
376 max3100_dowork(s);
377 /* always assert DCD and DSR since these lines are not wired */
378 return (s->cts ? TIOCM_CTS : 0) | TIOCM_DSR | TIOCM_CAR;
379}
380
381static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl)
382{
383 struct max3100_port *s = to_max3100_port(port);
384 int loopback, rts;
385
386 dev_dbg(&s->spi->dev, "%s\n", __func__);
387
388 loopback = (mctrl & TIOCM_LOOP) > 0;
389 rts = (mctrl & TIOCM_RTS) > 0;
390
391 spin_lock(&s->conf_lock);
392 if (s->loopback != loopback) {
393 s->loopback = loopback;
394 s->loopback_commit = 1;
395 }
396 if (s->rts != rts) {
397 s->rts = rts;
398 s->rts_commit = 1;
399 }
400 if (s->loopback_commit || s->rts_commit)
401 max3100_dowork(s);
402 spin_unlock(&s->conf_lock);
403}
404
405static void
406max3100_set_termios(struct uart_port *port, struct ktermios *termios,
407 const struct ktermios *old)
408{
409 struct max3100_port *s = to_max3100_port(port);
410 unsigned int baud = port->uartclk / 16;
411 unsigned int baud230400 = (baud == 230400) ? 1 : 0;
412 unsigned cflag;
413 u32 param_new, param_mask, parity = 0;
414
415 dev_dbg(&s->spi->dev, "%s\n", __func__);
416
417 cflag = termios->c_cflag;
418 param_mask = 0;
419
420 baud = tty_termios_baud_rate(termios);
421 param_new = s->conf & MAX3100_BAUD;
422 switch (baud) {
423 case 300:
424 if (baud230400)
425 baud = s->baud;
426 else
427 param_new = 15;
428 break;
429 case 600:
430 param_new = 14 + baud230400;
431 break;
432 case 1200:
433 param_new = 13 + baud230400;
434 break;
435 case 2400:
436 param_new = 12 + baud230400;
437 break;
438 case 4800:
439 param_new = 11 + baud230400;
440 break;
441 case 9600:
442 param_new = 10 + baud230400;
443 break;
444 case 19200:
445 param_new = 9 + baud230400;
446 break;
447 case 38400:
448 param_new = 8 + baud230400;
449 break;
450 case 57600:
451 param_new = 1 + baud230400;
452 break;
453 case 115200:
454 param_new = 0 + baud230400;
455 break;
456 case 230400:
457 if (baud230400)
458 param_new = 0;
459 else
460 baud = s->baud;
461 break;
462 default:
463 baud = s->baud;
464 }
465 tty_termios_encode_baud_rate(termios, baud, baud);
466 s->baud = baud;
467 param_mask |= MAX3100_BAUD;
468
469 if ((cflag & CSIZE) == CS8) {
470 param_new &= ~MAX3100_L;
471 parity &= ~MAX3100_7BIT;
472 } else {
473 param_new |= MAX3100_L;
474 parity |= MAX3100_7BIT;
475 cflag = (cflag & ~CSIZE) | CS7;
476 }
477 param_mask |= MAX3100_L;
478
479 if (cflag & CSTOPB)
480 param_new |= MAX3100_ST;
481 else
482 param_new &= ~MAX3100_ST;
483 param_mask |= MAX3100_ST;
484
485 if (cflag & PARENB) {
486 param_new |= MAX3100_PE;
487 parity |= MAX3100_PARITY_ON;
488 } else {
489 param_new &= ~MAX3100_PE;
490 parity &= ~MAX3100_PARITY_ON;
491 }
492 param_mask |= MAX3100_PE;
493
494 if (cflag & PARODD)
495 parity |= MAX3100_PARITY_ODD;
496 else
497 parity &= ~MAX3100_PARITY_ODD;
498
499 /* mask termios capabilities we don't support */
500 cflag &= ~CMSPAR;
501 termios->c_cflag = cflag;
502
503 s->port.ignore_status_mask = 0;
504 if (termios->c_iflag & IGNPAR)
505 s->port.ignore_status_mask |=
506 MAX3100_STATUS_PE | MAX3100_STATUS_FE |
507 MAX3100_STATUS_OE;
508
509 del_timer_sync(&s->timer);
510 uart_update_timeout(port, termios->c_cflag, baud);
511
512 spin_lock(&s->conf_lock);
513 s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
514 s->conf_commit = 1;
515 s->parity = parity;
516 spin_unlock(&s->conf_lock);
517 max3100_dowork(s);
518
519 if (UART_ENABLE_MS(&s->port, termios->c_cflag))
520 max3100_enable_ms(&s->port);
521}
522
523static void max3100_shutdown(struct uart_port *port)
524{
525 struct max3100_port *s = to_max3100_port(port);
526 u16 rx;
527
528 dev_dbg(&s->spi->dev, "%s\n", __func__);
529
530 if (s->suspending)
531 return;
532
533 s->force_end_work = 1;
534
535 del_timer_sync(&s->timer);
536
537 if (s->workqueue) {
538 destroy_workqueue(s->workqueue);
539 s->workqueue = NULL;
540 }
541 if (port->irq)
542 free_irq(port->irq, s);
543
544 /* set shutdown mode to save power */
545 max3100_sr(s, MAX3100_WC | MAX3100_SHDN, &rx);
546}
547
548static int max3100_startup(struct uart_port *port)
549{
550 struct max3100_port *s = to_max3100_port(port);
551 char b[12];
552 int ret;
553
554 dev_dbg(&s->spi->dev, "%s\n", __func__);
555
556 s->conf = MAX3100_RM;
557 s->baud = port->uartclk / 16;
558 s->rx_enabled = 1;
559
560 if (s->suspending)
561 return 0;
562
563 s->force_end_work = 0;
564 s->parity = 0;
565 s->rts = 0;
566
567 sprintf(b, "max3100-%d", s->minor);
568 s->workqueue = create_freezable_workqueue(b);
569 if (!s->workqueue) {
570 dev_warn(&s->spi->dev, "cannot create workqueue\n");
571 return -EBUSY;
572 }
573 INIT_WORK(&s->work, max3100_work);
574
575 ret = request_irq(port->irq, max3100_irq, IRQF_TRIGGER_FALLING, "max3100", s);
576 if (ret < 0) {
577 dev_warn(&s->spi->dev, "cannot allocate irq %d\n", port->irq);
578 port->irq = 0;
579 destroy_workqueue(s->workqueue);
580 s->workqueue = NULL;
581 return -EBUSY;
582 }
583
584 s->conf_commit = 1;
585 max3100_dowork(s);
586 /* wait for clock to settle */
587 msleep(50);
588
589 max3100_enable_ms(&s->port);
590
591 return 0;
592}
593
594static const char *max3100_type(struct uart_port *port)
595{
596 struct max3100_port *s = to_max3100_port(port);
597
598 dev_dbg(&s->spi->dev, "%s\n", __func__);
599
600 return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL;
601}
602
603static void max3100_release_port(struct uart_port *port)
604{
605 struct max3100_port *s = to_max3100_port(port);
606
607 dev_dbg(&s->spi->dev, "%s\n", __func__);
608}
609
610static void max3100_config_port(struct uart_port *port, int flags)
611{
612 struct max3100_port *s = to_max3100_port(port);
613
614 dev_dbg(&s->spi->dev, "%s\n", __func__);
615
616 if (flags & UART_CONFIG_TYPE)
617 s->port.type = PORT_MAX3100;
618}
619
620static int max3100_verify_port(struct uart_port *port,
621 struct serial_struct *ser)
622{
623 struct max3100_port *s = to_max3100_port(port);
624 int ret = -EINVAL;
625
626 dev_dbg(&s->spi->dev, "%s\n", __func__);
627
628 if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100)
629 ret = 0;
630 return ret;
631}
632
633static void max3100_stop_tx(struct uart_port *port)
634{
635 struct max3100_port *s = to_max3100_port(port);
636
637 dev_dbg(&s->spi->dev, "%s\n", __func__);
638}
639
640static int max3100_request_port(struct uart_port *port)
641{
642 struct max3100_port *s = to_max3100_port(port);
643
644 dev_dbg(&s->spi->dev, "%s\n", __func__);
645 return 0;
646}
647
648static void max3100_break_ctl(struct uart_port *port, int break_state)
649{
650 struct max3100_port *s = to_max3100_port(port);
651
652 dev_dbg(&s->spi->dev, "%s\n", __func__);
653}
654
655static const struct uart_ops max3100_ops = {
656 .tx_empty = max3100_tx_empty,
657 .set_mctrl = max3100_set_mctrl,
658 .get_mctrl = max3100_get_mctrl,
659 .stop_tx = max3100_stop_tx,
660 .start_tx = max3100_start_tx,
661 .stop_rx = max3100_stop_rx,
662 .enable_ms = max3100_enable_ms,
663 .break_ctl = max3100_break_ctl,
664 .startup = max3100_startup,
665 .shutdown = max3100_shutdown,
666 .set_termios = max3100_set_termios,
667 .type = max3100_type,
668 .release_port = max3100_release_port,
669 .request_port = max3100_request_port,
670 .config_port = max3100_config_port,
671 .verify_port = max3100_verify_port,
672};
673
674static struct uart_driver max3100_uart_driver = {
675 .owner = THIS_MODULE,
676 .driver_name = "ttyMAX",
677 .dev_name = "ttyMAX",
678 .major = MAX3100_MAJOR,
679 .minor = MAX3100_MINOR,
680 .nr = MAX_MAX3100,
681};
682static int uart_driver_registered;
683
684static int max3100_probe(struct spi_device *spi)
685{
686 struct device *dev = &spi->dev;
687 int i, retval;
688 u16 rx;
689
690 mutex_lock(&max3100s_lock);
691
692 if (!uart_driver_registered) {
693 retval = uart_register_driver(&max3100_uart_driver);
694 if (retval) {
695 mutex_unlock(&max3100s_lock);
696 return dev_err_probe(dev, retval, "Couldn't register max3100 uart driver\n");
697 }
698
699 uart_driver_registered = 1;
700 }
701
702 for (i = 0; i < MAX_MAX3100; i++)
703 if (!max3100s[i])
704 break;
705 if (i == MAX_MAX3100) {
706 mutex_unlock(&max3100s_lock);
707 return dev_err_probe(dev, -ENOMEM, "too many MAX3100 chips\n");
708 }
709
710 max3100s[i] = kzalloc(sizeof(struct max3100_port), GFP_KERNEL);
711 if (!max3100s[i]) {
712 mutex_unlock(&max3100s_lock);
713 return -ENOMEM;
714 }
715 max3100s[i]->spi = spi;
716 spin_lock_init(&max3100s[i]->conf_lock);
717 spi_set_drvdata(spi, max3100s[i]);
718 max3100s[i]->minor = i;
719 timer_setup(&max3100s[i]->timer, max3100_timeout, 0);
720
721 dev_dbg(&spi->dev, "%s: adding port %d\n", __func__, i);
722 max3100s[i]->port.irq = spi->irq;
723 max3100s[i]->port.fifosize = 16;
724 max3100s[i]->port.ops = &max3100_ops;
725 max3100s[i]->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
726 max3100s[i]->port.line = i;
727 max3100s[i]->port.type = PORT_MAX3100;
728 max3100s[i]->port.dev = &spi->dev;
729
730 /* Read clock frequency from a property, uart_add_one_port() will fail if it's not set */
731 device_property_read_u32(dev, "clock-frequency", &max3100s[i]->port.uartclk);
732
733 retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port);
734 if (retval < 0)
735 dev_err_probe(dev, retval, "uart_add_one_port failed for line %d\n", i);
736
737 /* set shutdown mode to save power. Will be woken-up on open */
738 max3100_sr(max3100s[i], MAX3100_WC | MAX3100_SHDN, &rx);
739 mutex_unlock(&max3100s_lock);
740 return 0;
741}
742
743static void max3100_remove(struct spi_device *spi)
744{
745 struct max3100_port *s = spi_get_drvdata(spi);
746 int i;
747
748 mutex_lock(&max3100s_lock);
749
750 /* find out the index for the chip we are removing */
751 for (i = 0; i < MAX_MAX3100; i++)
752 if (max3100s[i] == s) {
753 dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i);
754 uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port);
755 kfree(max3100s[i]);
756 max3100s[i] = NULL;
757 break;
758 }
759
760 WARN_ON(i == MAX_MAX3100);
761
762 /* check if this is the last chip we have */
763 for (i = 0; i < MAX_MAX3100; i++)
764 if (max3100s[i]) {
765 mutex_unlock(&max3100s_lock);
766 return;
767 }
768 pr_debug("removing max3100 driver\n");
769 uart_unregister_driver(&max3100_uart_driver);
770 uart_driver_registered = 0;
771
772 mutex_unlock(&max3100s_lock);
773}
774
775static int max3100_suspend(struct device *dev)
776{
777 struct max3100_port *s = dev_get_drvdata(dev);
778 u16 rx;
779
780 dev_dbg(&s->spi->dev, "%s\n", __func__);
781
782 disable_irq(s->port.irq);
783
784 s->suspending = 1;
785 uart_suspend_port(&max3100_uart_driver, &s->port);
786
787 /* no HW suspend, so do SW one */
788 max3100_sr(s, MAX3100_WC | MAX3100_SHDN, &rx);
789 return 0;
790}
791
792static int max3100_resume(struct device *dev)
793{
794 struct max3100_port *s = dev_get_drvdata(dev);
795
796 dev_dbg(&s->spi->dev, "%s\n", __func__);
797
798 uart_resume_port(&max3100_uart_driver, &s->port);
799 s->suspending = 0;
800
801 enable_irq(s->port.irq);
802
803 s->conf_commit = 1;
804 if (s->workqueue)
805 max3100_dowork(s);
806
807 return 0;
808}
809
810static DEFINE_SIMPLE_DEV_PM_OPS(max3100_pm_ops, max3100_suspend, max3100_resume);
811
812static const struct spi_device_id max3100_spi_id[] = {
813 { "max3100" },
814 { }
815};
816MODULE_DEVICE_TABLE(spi, max3100_spi_id);
817
818static const struct of_device_id max3100_of_match[] = {
819 { .compatible = "maxim,max3100" },
820 { }
821};
822MODULE_DEVICE_TABLE(of, max3100_of_match);
823
824static struct spi_driver max3100_driver = {
825 .driver = {
826 .name = "max3100",
827 .of_match_table = max3100_of_match,
828 .pm = pm_sleep_ptr(&max3100_pm_ops),
829 },
830 .probe = max3100_probe,
831 .remove = max3100_remove,
832 .id_table = max3100_spi_id,
833};
834
835module_spi_driver(max3100_driver);
836
837MODULE_DESCRIPTION("MAX3100 driver");
838MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
839MODULE_LICENSE("GPL");