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tty: add SPDX identifiers to all remaining files in drivers/tty/
[linux-2.6-block.git] / drivers / tty / serial / max3100.c
CommitLineData
e3b3d0f5 1// SPDX-License-Identifier: GPL-2.0+
7831d56b
AC		 2/*
3 *
4 * Copyright (C) 2008 Christian Pellegrin <chripell@evolware.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 *
12 * Notes: the MAX3100 doesn't provide an interrupt on CTS so we have
13 * to use polling for flow control. TX empty IRQ is unusable, since
14 * writing conf clears FIFO buffer and we cannot have this interrupt
15 * always asking us for attention.
16 *
17 * Example platform data:
18
19 static struct plat_max3100 max3100_plat_data = {
20 .loopback = 0,
21 .crystal = 0,
22 .poll_time = 100,
23 };
24
25 static struct spi_board_info spi_board_info[] = {
26 {
27 .modalias = "max3100",
28 .platform_data = &max3100_plat_data,
29 .irq = IRQ_EINT12,
30 .max_speed_hz = 5*1000*1000,
31 .chip_select = 0,
32 },
33 };
34
35 * The initial minor number is 209 in the low-density serial port:
36 * mknod /dev/ttyMAX0 c 204 209
37 */
38
39#define MAX3100_MAJOR 204
40#define MAX3100_MINOR 209
41/* 4 MAX3100s should be enough for everyone */
42#define MAX_MAX3100 4
43
44#include <linux/delay.h>
5a0e3ad6 45#include <linux/slab.h>
7831d56b 46#include <linux/device.h>
578b9ce0 47#include <linux/module.h>
7831d56b
AC		 48#include <linux/serial_core.h>
49#include <linux/serial.h>
50#include <linux/spi/spi.h>
51#include <linux/freezer.h>
ee160a38
JS		 52#include <linux/tty.h>
53#include <linux/tty_flip.h>
7831d56b
AC		 54
55#include <linux/serial_max3100.h>
56
57#define MAX3100_C (1<<14)
58#define MAX3100_D (0<<14)
59#define MAX3100_W (1<<15)
60#define MAX3100_RX (0<<15)
61
62#define MAX3100_WC (MAX3100_W | MAX3100_C)
63#define MAX3100_RC (MAX3100_RX | MAX3100_C)
64#define MAX3100_WD (MAX3100_W | MAX3100_D)
65#define MAX3100_RD (MAX3100_RX | MAX3100_D)
66#define MAX3100_CMD (3 << 14)
67
68#define MAX3100_T (1<<14)
69#define MAX3100_R (1<<15)
70
71#define MAX3100_FEN (1<<13)
72#define MAX3100_SHDN (1<<12)
73#define MAX3100_TM (1<<11)
74#define MAX3100_RM (1<<10)
75#define MAX3100_PM (1<<9)
76#define MAX3100_RAM (1<<8)
77#define MAX3100_IR (1<<7)
78#define MAX3100_ST (1<<6)
79#define MAX3100_PE (1<<5)
80#define MAX3100_L (1<<4)
81#define MAX3100_BAUD (0xf)
82
83#define MAX3100_TE (1<<10)
84#define MAX3100_RAFE (1<<10)
85#define MAX3100_RTS (1<<9)
86#define MAX3100_CTS (1<<9)
87#define MAX3100_PT (1<<8)
88#define MAX3100_DATA (0xff)
89
90#define MAX3100_RT (MAX3100_R | MAX3100_T)
91#define MAX3100_RTC (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE)
92
93/* the following simulate a status reg for ignore_status_mask */
94#define MAX3100_STATUS_PE 1
95#define MAX3100_STATUS_FE 2
96#define MAX3100_STATUS_OE 4
97
98struct max3100_port {
99 struct uart_port port;
100 struct spi_device *spi;
101
102 int cts; /* last CTS received for flow ctrl */
103 int tx_empty; /* last TX empty bit */
104
105 spinlock_t conf_lock; /* shared data */
106 int conf_commit; /* need to make changes */
107 int conf; /* configuration for the MAX31000
108 * (bits 0-7, bits 8-11 are irqs) */
109 int rts_commit; /* need to change rts */
110 int rts; /* rts status */
111 int baud; /* current baud rate */
112
113 int parity; /* keeps track if we should send parity */
114#define MAX3100_PARITY_ON 1
115#define MAX3100_PARITY_ODD 2
116#define MAX3100_7BIT 4
117 int rx_enabled; /* if we should rx chars */
118
119 int irq; /* irq assigned to the max3100 */
120
121 int minor; /* minor number */
122 int crystal; /* 1 if 3.6864Mhz crystal 0 for 1.8432 */
123 int loopback; /* 1 if we are in loopback mode */
124
125 /* for handling irqs: need workqueue since we do spi_sync */
126 struct workqueue_struct *workqueue;
127 struct work_struct work;
128 /* set to 1 to make the workhandler exit as soon as possible */
129 int force_end_work;
130 /* need to know we are suspending to avoid deadlock on workqueue */
131 int suspending;
132
133 /* hook for suspending MAX3100 via dedicated pin */
134 void (*max3100_hw_suspend) (int suspend);
135
136 /* poll time (in ms) for ctrl lines */
137 int poll_time;
138 /* and its timer */
139 struct timer_list timer;
140};
141
142static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
143static DEFINE_MUTEX(max3100s_lock); /* race on probe */
144
145static int max3100_do_parity(struct max3100_port *s, u16 c)
146{
147 int parity;
148
149 if (s->parity & MAX3100_PARITY_ODD)
150 parity = 1;
151 else
152 parity = 0;
153
154 if (s->parity & MAX3100_7BIT)
155 c &= 0x7f;
156 else
157 c &= 0xff;
158
159 parity = parity ^ (hweight8(c) & 1);
160 return parity;
161}
162
163static int max3100_check_parity(struct max3100_port *s, u16 c)
164{
165 return max3100_do_parity(s, c) == ((c >> 8) & 1);
166}
167
168static void max3100_calc_parity(struct max3100_port *s, u16 *c)
169{
170 if (s->parity & MAX3100_7BIT)
171 *c &= 0x7f;
172 else
173 *c &= 0xff;
174
175 if (s->parity & MAX3100_PARITY_ON)
176 *c |= max3100_do_parity(s, *c) << 8;
177}
178
179static void max3100_work(struct work_struct *w);
180
181static void max3100_dowork(struct max3100_port *s)
182{
7998005b 183 if (!s->force_end_work && !freezing(current) && !s->suspending)
7831d56b
AC		 184 queue_work(s->workqueue, &s->work);
185}
186
187static void max3100_timeout(unsigned long data)
188{
189 struct max3100_port *s = (struct max3100_port *)data;
190
ebd2c8f6 191 if (s->port.state) {
7831d56b
AC		 192 max3100_dowork(s);
193 mod_timer(&s->timer, jiffies + s->poll_time);
194 }
195}
196
197static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx)
198{
199 struct spi_message message;
200 u16 etx, erx;
201 int status;
202 struct spi_transfer tran = {
203 .tx_buf = &etx,
204 .rx_buf = &erx,
205 .len = 2,
206 };
207
208 etx = cpu_to_be16(tx);
209 spi_message_init(&message);
210 spi_message_add_tail(&tran, &message);
211 status = spi_sync(s->spi, &message);
212 if (status) {
213 dev_warn(&s->spi->dev, "error while calling spi_sync\n");
214 return -EIO;
215 }
216 *rx = be16_to_cpu(erx);
217 s->tx_empty = (*rx & MAX3100_T) > 0;
218 dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
219 return 0;
220}
221
222static int max3100_handlerx(struct max3100_port *s, u16 rx)
223{
224 unsigned int ch, flg, status = 0;
225 int ret = 0, cts;
226
227 if (rx & MAX3100_R && s->rx_enabled) {
228 dev_dbg(&s->spi->dev, "%s\n", __func__);
229 ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff);
230 if (rx & MAX3100_RAFE) {
231 s->port.icount.frame++;
232 flg = TTY_FRAME;
233 status |= MAX3100_STATUS_FE;
234 } else {
235 if (s->parity & MAX3100_PARITY_ON) {
236 if (max3100_check_parity(s, rx)) {
237 s->port.icount.rx++;
238 flg = TTY_NORMAL;
239 } else {
240 s->port.icount.parity++;
241 flg = TTY_PARITY;
242 status |= MAX3100_STATUS_PE;
243 }
244 } else {
245 s->port.icount.rx++;
246 flg = TTY_NORMAL;
247 }
248 }
249 uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg);
250 ret = 1;
251 }
252
253 cts = (rx & MAX3100_CTS) > 0;
254 if (s->cts != cts) {
255 s->cts = cts;
256 uart_handle_cts_change(&s->port, cts ? TIOCM_CTS : 0);
257 }
258
259 return ret;
260}
261
262static void max3100_work(struct work_struct *w)
263{
264 struct max3100_port *s = container_of(w, struct max3100_port, work);
265 int rxchars;
266 u16 tx, rx;
5de15cc2 267 int conf, cconf, crts;
ebd2c8f6 268 struct circ_buf *xmit = &s->port.state->xmit;
7831d56b
AC		 269
270 dev_dbg(&s->spi->dev, "%s\n", __func__);
271
272 rxchars = 0;
273 do {
274 spin_lock(&s->conf_lock);
275 conf = s->conf;
276 cconf = s->conf_commit;
277 s->conf_commit = 0;
7831d56b
AC		 278 crts = s->rts_commit;
279 s->rts_commit = 0;
280 spin_unlock(&s->conf_lock);
281 if (cconf)
282 max3100_sr(s, MAX3100_WC | conf, &rx);
283 if (crts) {
284 max3100_sr(s, MAX3100_WD | MAX3100_TE |
285 (s->rts ? MAX3100_RTS : 0), &rx);
286 rxchars += max3100_handlerx(s, rx);
287 }
288
289 max3100_sr(s, MAX3100_RD, &rx);
290 rxchars += max3100_handlerx(s, rx);
291
292 if (rx & MAX3100_T) {
293 tx = 0xffff;
294 if (s->port.x_char) {
295 tx = s->port.x_char;
296 s->port.icount.tx++;
297 s->port.x_char = 0;
298 } else if (!uart_circ_empty(xmit) &&
299 !uart_tx_stopped(&s->port)) {
300 tx = xmit->buf[xmit->tail];
301 xmit->tail = (xmit->tail + 1) &
302 (UART_XMIT_SIZE - 1);
303 s->port.icount.tx++;
304 }
305 if (tx != 0xffff) {
306 max3100_calc_parity(s, &tx);
307 tx |= MAX3100_WD | (s->rts ? MAX3100_RTS : 0);
308 max3100_sr(s, tx, &rx);
309 rxchars += max3100_handlerx(s, rx);
310 }
311 }
312
2e124b4a
JS		 313 if (rxchars > 16) {
314 tty_flip_buffer_push(&s->port.state->port);
7831d56b
AC		 315 rxchars = 0;
316 }
317 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
318 uart_write_wakeup(&s->port);
319
320 } while (!s->force_end_work &&
321 !freezing(current) &&
322 ((rx & MAX3100_R) ||
323 (!uart_circ_empty(xmit) &&
324 !uart_tx_stopped(&s->port))));
325
2e124b4a
JS		 326 if (rxchars > 0)
327 tty_flip_buffer_push(&s->port.state->port);
7831d56b
AC		 328}
329
330static irqreturn_t max3100_irq(int irqno, void *dev_id)
331{
332 struct max3100_port *s = dev_id;
333
334 dev_dbg(&s->spi->dev, "%s\n", __func__);
335
336 max3100_dowork(s);
337 return IRQ_HANDLED;
338}
339
340static void max3100_enable_ms(struct uart_port *port)
341{
342 struct max3100_port *s = container_of(port,
343 struct max3100_port,
344 port);
345
346 if (s->poll_time > 0)
347 mod_timer(&s->timer, jiffies);
348 dev_dbg(&s->spi->dev, "%s\n", __func__);
349}
350
351static void max3100_start_tx(struct uart_port *port)
352{
353 struct max3100_port *s = container_of(port,
354 struct max3100_port,
355 port);
356
357 dev_dbg(&s->spi->dev, "%s\n", __func__);
358
359 max3100_dowork(s);
360}
361
362static void max3100_stop_rx(struct uart_port *port)
363{
364 struct max3100_port *s = container_of(port,
365 struct max3100_port,
366 port);
367
368 dev_dbg(&s->spi->dev, "%s\n", __func__);
369
370 s->rx_enabled = 0;
371 spin_lock(&s->conf_lock);
372 s->conf &= ~MAX3100_RM;
373 s->conf_commit = 1;
374 spin_unlock(&s->conf_lock);
375 max3100_dowork(s);
376}
377
378static unsigned int max3100_tx_empty(struct uart_port *port)
379{
380 struct max3100_port *s = container_of(port,
381 struct max3100_port,
382 port);
383
384 dev_dbg(&s->spi->dev, "%s\n", __func__);
385
386 /* may not be truly up-to-date */
387 max3100_dowork(s);
388 return s->tx_empty;
389}
390
391static unsigned int max3100_get_mctrl(struct uart_port *port)
392{
393 struct max3100_port *s = container_of(port,
394 struct max3100_port,
395 port);
396
397 dev_dbg(&s->spi->dev, "%s\n", __func__);
398
399 /* may not be truly up-to-date */
400 max3100_dowork(s);
401 /* always assert DCD and DSR since these lines are not wired */
402 return (s->cts ? TIOCM_CTS : 0) | TIOCM_DSR | TIOCM_CAR;
403}
404
405static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl)
406{
407 struct max3100_port *s = container_of(port,
408 struct max3100_port,
409 port);
410 int rts;
411
412 dev_dbg(&s->spi->dev, "%s\n", __func__);
413
414 rts = (mctrl & TIOCM_RTS) > 0;
415
416 spin_lock(&s->conf_lock);
417 if (s->rts != rts) {
418 s->rts = rts;
419 s->rts_commit = 1;
420 max3100_dowork(s);
421 }
422 spin_unlock(&s->conf_lock);
423}
424
425static void
426max3100_set_termios(struct uart_port *port, struct ktermios *termios,
427 struct ktermios *old)
428{
429 struct max3100_port *s = container_of(port,
430 struct max3100_port,
431 port);
432 int baud = 0;
433 unsigned cflag;
434 u32 param_new, param_mask, parity = 0;
7831d56b
AC		 435
436 dev_dbg(&s->spi->dev, "%s\n", __func__);
7831d56b
AC		 437
438 cflag = termios->c_cflag;
7831d56b
AC		 439 param_mask = 0;
440
eab4f5af 441 baud = tty_termios_baud_rate(termios);
7831d56b
AC		 442 param_new = s->conf & MAX3100_BAUD;
443 switch (baud) {
444 case 300:
445 if (s->crystal)
446 baud = s->baud;
447 else
448 param_new = 15;
449 break;
450 case 600:
451 param_new = 14 + s->crystal;
452 break;
453 case 1200:
454 param_new = 13 + s->crystal;
455 break;
456 case 2400:
457 param_new = 12 + s->crystal;
458 break;
459 case 4800:
460 param_new = 11 + s->crystal;
461 break;
462 case 9600:
463 param_new = 10 + s->crystal;
464 break;
465 case 19200:
466 param_new = 9 + s->crystal;
467 break;
468 case 38400:
469 param_new = 8 + s->crystal;
470 break;
471 case 57600:
472 param_new = 1 + s->crystal;
473 break;
474 case 115200:
475 param_new = 0 + s->crystal;
476 break;
477 case 230400:
478 if (s->crystal)
479 param_new = 0;
480 else
481 baud = s->baud;
482 break;
483 default:
484 baud = s->baud;
485 }
eab4f5af 486 tty_termios_encode_baud_rate(termios, baud, baud);
7831d56b
AC		 487 s->baud = baud;
488 param_mask |= MAX3100_BAUD;
489
490 if ((cflag & CSIZE) == CS8) {
491 param_new &= ~MAX3100_L;
492 parity &= ~MAX3100_7BIT;
493 } else {
494 param_new |= MAX3100_L;
495 parity |= MAX3100_7BIT;
496 cflag = (cflag & ~CSIZE) | CS7;
497 }
498 param_mask |= MAX3100_L;
499
500 if (cflag & CSTOPB)
501 param_new |= MAX3100_ST;
502 else
503 param_new &= ~MAX3100_ST;
504 param_mask |= MAX3100_ST;
505
506 if (cflag & PARENB) {
507 param_new |= MAX3100_PE;
508 parity |= MAX3100_PARITY_ON;
509 } else {
510 param_new &= ~MAX3100_PE;
511 parity &= ~MAX3100_PARITY_ON;
512 }
513 param_mask |= MAX3100_PE;
514
515 if (cflag & PARODD)
516 parity |= MAX3100_PARITY_ODD;
517 else
518 parity &= ~MAX3100_PARITY_ODD;
519
520 /* mask termios capabilities we don't support */
521 cflag &= ~CMSPAR;
522 termios->c_cflag = cflag;
523
524 s->port.ignore_status_mask = 0;
525 if (termios->c_iflag & IGNPAR)
526 s->port.ignore_status_mask |=
527 MAX3100_STATUS_PE | MAX3100_STATUS_FE |
528 MAX3100_STATUS_OE;
529
530 /* we are sending char from a workqueue so enable */
d6c53c0e 531 s->port.state->port.low_latency = 1;
7831d56b
AC		 532
533 if (s->poll_time > 0)
534 del_timer_sync(&s->timer);
535
536 uart_update_timeout(port, termios->c_cflag, baud);
537
538 spin_lock(&s->conf_lock);
539 s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
540 s->conf_commit = 1;
541 s->parity = parity;
542 spin_unlock(&s->conf_lock);
543 max3100_dowork(s);
544
545 if (UART_ENABLE_MS(&s->port, termios->c_cflag))
546 max3100_enable_ms(&s->port);
547}
548
549static void max3100_shutdown(struct uart_port *port)
550{
551 struct max3100_port *s = container_of(port,
552 struct max3100_port,
553 port);
554
555 dev_dbg(&s->spi->dev, "%s\n", __func__);
556
557 if (s->suspending)
558 return;
559
560 s->force_end_work = 1;
561
562 if (s->poll_time > 0)
563 del_timer_sync(&s->timer);
564
565 if (s->workqueue) {
566 flush_workqueue(s->workqueue);
567 destroy_workqueue(s->workqueue);
568 s->workqueue = NULL;
569 }
570 if (s->irq)
571 free_irq(s->irq, s);
572
573 /* set shutdown mode to save power */
574 if (s->max3100_hw_suspend)
575 s->max3100_hw_suspend(1);
576 else {
577 u16 tx, rx;
578
579 tx = MAX3100_WC | MAX3100_SHDN;
580 max3100_sr(s, tx, &rx);
581 }
582}
583
584static int max3100_startup(struct uart_port *port)
585{
586 struct max3100_port *s = container_of(port,
587 struct max3100_port,
588 port);
589 char b[12];
590
591 dev_dbg(&s->spi->dev, "%s\n", __func__);
592
593 s->conf = MAX3100_RM;
594 s->baud = s->crystal ? 230400 : 115200;
595 s->rx_enabled = 1;
596
597 if (s->suspending)
598 return 0;
599
600 s->force_end_work = 0;
601 s->parity = 0;
602 s->rts = 0;
603
604 sprintf(b, "max3100-%d", s->minor);
58a69cb4 605 s->workqueue = create_freezable_workqueue(b);
7831d56b
AC		 606 if (!s->workqueue) {
607 dev_warn(&s->spi->dev, "cannot create workqueue\n");
608 return -EBUSY;
609 }
610 INIT_WORK(&s->work, max3100_work);
611
612 if (request_irq(s->irq, max3100_irq,
613 IRQF_TRIGGER_FALLING, "max3100", s) < 0) {
614 dev_warn(&s->spi->dev, "cannot allocate irq %d\n", s->irq);
615 s->irq = 0;
616 destroy_workqueue(s->workqueue);
617 s->workqueue = NULL;
618 return -EBUSY;
619 }
620
621 if (s->loopback) {
622 u16 tx, rx;
623 tx = 0x4001;
624 max3100_sr(s, tx, &rx);
625 }
626
627 if (s->max3100_hw_suspend)
628 s->max3100_hw_suspend(0);
629 s->conf_commit = 1;
630 max3100_dowork(s);
631 /* wait for clock to settle */
632 msleep(50);
633
634 max3100_enable_ms(&s->port);
635
636 return 0;
637}
638
639static const char *max3100_type(struct uart_port *port)
640{
641 struct max3100_port *s = container_of(port,
642 struct max3100_port,
643 port);
644
645 dev_dbg(&s->spi->dev, "%s\n", __func__);
646
647 return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL;
648}
649
650static void max3100_release_port(struct uart_port *port)
651{
652 struct max3100_port *s = container_of(port,
653 struct max3100_port,
654 port);
655
656 dev_dbg(&s->spi->dev, "%s\n", __func__);
657}
658
659static void max3100_config_port(struct uart_port *port, int flags)
660{
661 struct max3100_port *s = container_of(port,
662 struct max3100_port,
663 port);
664
665 dev_dbg(&s->spi->dev, "%s\n", __func__);
666
667 if (flags & UART_CONFIG_TYPE)
668 s->port.type = PORT_MAX3100;
669}
670
671static int max3100_verify_port(struct uart_port *port,
672 struct serial_struct *ser)
673{
674 struct max3100_port *s = container_of(port,
675 struct max3100_port,
676 port);
677 int ret = -EINVAL;
678
679 dev_dbg(&s->spi->dev, "%s\n", __func__);
680
681 if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100)
682 ret = 0;
683 return ret;
684}
685
686static void max3100_stop_tx(struct uart_port *port)
687{
688 struct max3100_port *s = container_of(port,
689 struct max3100_port,
690 port);
691
692 dev_dbg(&s->spi->dev, "%s\n", __func__);
693}
694
695static int max3100_request_port(struct uart_port *port)
696{
697 struct max3100_port *s = container_of(port,
698 struct max3100_port,
699 port);
700
701 dev_dbg(&s->spi->dev, "%s\n", __func__);
702 return 0;
703}
704
705static void max3100_break_ctl(struct uart_port *port, int break_state)
706{
707 struct max3100_port *s = container_of(port,
708 struct max3100_port,
709 port);
710
711 dev_dbg(&s->spi->dev, "%s\n", __func__);
712}
713
069a47e5 714static const struct uart_ops max3100_ops = {
7831d56b
AC		 715 .tx_empty = max3100_tx_empty,
716 .set_mctrl = max3100_set_mctrl,
717 .get_mctrl = max3100_get_mctrl,
718 .stop_tx = max3100_stop_tx,
719 .start_tx = max3100_start_tx,
720 .stop_rx = max3100_stop_rx,
721 .enable_ms = max3100_enable_ms,
722 .break_ctl = max3100_break_ctl,
723 .startup = max3100_startup,
724 .shutdown = max3100_shutdown,
725 .set_termios = max3100_set_termios,
726 .type = max3100_type,
727 .release_port = max3100_release_port,
728 .request_port = max3100_request_port,
729 .config_port = max3100_config_port,
730 .verify_port = max3100_verify_port,
731};
732
733static struct uart_driver max3100_uart_driver = {
734 .owner = THIS_MODULE,
735 .driver_name = "ttyMAX",
736 .dev_name = "ttyMAX",
737 .major = MAX3100_MAJOR,
738 .minor = MAX3100_MINOR,
739 .nr = MAX_MAX3100,
740};
741static int uart_driver_registered;
742
9671f099 743static int max3100_probe(struct spi_device *spi)
7831d56b
AC		 744{
745 int i, retval;
746 struct plat_max3100 *pdata;
747 u16 tx, rx;
748
749 mutex_lock(&max3100s_lock);
750
751 if (!uart_driver_registered) {
752 uart_driver_registered = 1;
753 retval = uart_register_driver(&max3100_uart_driver);
754 if (retval) {
755 printk(KERN_ERR "Couldn't register max3100 uart driver\n");
756 mutex_unlock(&max3100s_lock);
757 return retval;
758 }
759 }
760
761 for (i = 0; i < MAX_MAX3100; i++)
762 if (!max3100s[i])
763 break;
764 if (i == MAX_MAX3100) {
765 dev_warn(&spi->dev, "too many MAX3100 chips\n");
766 mutex_unlock(&max3100s_lock);
767 return -ENOMEM;
768 }
769
770 max3100s[i] = kzalloc(sizeof(struct max3100_port), GFP_KERNEL);
771 if (!max3100s[i]) {
772 dev_warn(&spi->dev,
773 "kmalloc for max3100 structure %d failed!\n", i);
774 mutex_unlock(&max3100s_lock);
775 return -ENOMEM;
776 }
777 max3100s[i]->spi = spi;
778 max3100s[i]->irq = spi->irq;
779 spin_lock_init(&max3100s[i]->conf_lock);
31bdfc64 780 spi_set_drvdata(spi, max3100s[i]);
574de559 781 pdata = dev_get_platdata(&spi->dev);
7831d56b
AC		 782 max3100s[i]->crystal = pdata->crystal;
783 max3100s[i]->loopback = pdata->loopback;
c89b7370 784 max3100s[i]->poll_time = msecs_to_jiffies(pdata->poll_time);
7831d56b
AC		 785 if (pdata->poll_time > 0 && max3100s[i]->poll_time == 0)
786 max3100s[i]->poll_time = 1;
787 max3100s[i]->max3100_hw_suspend = pdata->max3100_hw_suspend;
788 max3100s[i]->minor = i;
71fa5272
AP		 789 setup_timer(&max3100s[i]->timer, max3100_timeout,
790 (unsigned long)max3100s[i]);
7831d56b
AC		 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
ae8d8a14 818static int max3100_remove(struct spi_device *spi)
7831d56b 819{
31bdfc64 820 struct max3100_port *s = spi_get_drvdata(spi);
7831d56b
AC		 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++)
41fda9c4
AC		 827 if (max3100s[i] == s) {
828 dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i);
829 uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port);
830 kfree(max3100s[i]);
831 max3100s[i] = NULL;
7831d56b 832 break;
41fda9c4 833 }
7831d56b 834
41fda9c4
AC		 835 WARN_ON(i == MAX_MAX3100);
836
7831d56b
AC		 837 /* check if this is the last chip we have */
838 for (i = 0; i < MAX_MAX3100; i++)
839 if (max3100s[i]) {
840 mutex_unlock(&max3100s_lock);
841 return 0;
842 }
843 pr_debug("removing max3100 driver\n");
844 uart_unregister_driver(&max3100_uart_driver);
845
846 mutex_unlock(&max3100s_lock);
847 return 0;
848}
849
c47ddc26 850#ifdef CONFIG_PM_SLEEP
7831d56b 851
c47ddc26 852static int max3100_suspend(struct device *dev)
7831d56b 853{
c47ddc26 854 struct max3100_port *s = dev_get_drvdata(dev);
7831d56b
AC		 855
856 dev_dbg(&s->spi->dev, "%s\n", __func__);
857
858 disable_irq(s->irq);
859
860 s->suspending = 1;
861 uart_suspend_port(&max3100_uart_driver, &s->port);
862
863 if (s->max3100_hw_suspend)
864 s->max3100_hw_suspend(1);
865 else {
866 /* no HW suspend, so do SW one */
867 u16 tx, rx;
868
869 tx = MAX3100_WC | MAX3100_SHDN;
870 max3100_sr(s, tx, &rx);
871 }
872 return 0;
873}
874
c47ddc26 875static int max3100_resume(struct device *dev)
7831d56b 876{
c47ddc26 877 struct max3100_port *s = dev_get_drvdata(dev);
7831d56b
AC		 878
879 dev_dbg(&s->spi->dev, "%s\n", __func__);
880
881 if (s->max3100_hw_suspend)
882 s->max3100_hw_suspend(0);
883 uart_resume_port(&max3100_uart_driver, &s->port);
884 s->suspending = 0;
885
886 enable_irq(s->irq);
887
888 s->conf_commit = 1;
889 if (s->workqueue)
890 max3100_dowork(s);
891
892 return 0;
893}
894
c47ddc26
LPC		 895static SIMPLE_DEV_PM_OPS(max3100_pm_ops, max3100_suspend, max3100_resume);
896#define MAX3100_PM_OPS (&max3100_pm_ops)
897
7831d56b 898#else
c47ddc26 899#define MAX3100_PM_OPS NULL
7831d56b
AC		 900#endif
901
902static struct spi_driver max3100_driver = {
903 .driver = {
904 .name = "max3100",
c47ddc26 905 .pm = MAX3100_PM_OPS,
7831d56b 906 },
7831d56b 907 .probe = max3100_probe,
2d47b716 908 .remove = max3100_remove,
7831d56b
AC		 909};
910
c0fc208e 911module_spi_driver(max3100_driver);
7831d56b
AC		 912
913MODULE_DESCRIPTION("MAX3100 driver");
914MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
915MODULE_LICENSE("GPL");
e0626e38 916MODULE_ALIAS("spi:max3100");
Linux 6.x block layer and io_uring tree(s)