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
78 struct 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
to_max3100_port(struct uart_port * port)114 static inline struct max3100_port *to_max3100_port(struct uart_port *port)
115 {
116 return container_of(port, struct max3100_port, port);
117 }
118
119 static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
120 static DEFINE_MUTEX(max3100s_lock); /* race on probe */
121
max3100_do_parity(struct max3100_port * s,u16 c)122 static 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
max3100_check_parity(struct max3100_port * s,u16 c)140 static int max3100_check_parity(struct max3100_port *s, u16 c)
141 {
142 return max3100_do_parity(s, c) == ((c >> 8) & 1);
143 }
144
max3100_calc_parity(struct max3100_port * s,u16 * c)145 static 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
max3100_sr(struct max3100_port * s,u16 tx,u16 * rx)156 static 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
max3100_handlerx_unlocked(struct max3100_port * s,u16 rx)181 static 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
max3100_handlerx(struct max3100_port * s,u16 rx)222 static 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
max3100_work(struct work_struct * w)233 static 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
max3100_dowork(struct max3100_port * s)303 static 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
max3100_timeout(struct timer_list * t)309 static 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
max3100_irq(int irqno,void * dev_id)317 static 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
max3100_enable_ms(struct uart_port * port)327 static 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
max3100_start_tx(struct uart_port * port)335 static 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
max3100_stop_rx(struct uart_port * port)344 static 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
max3100_tx_empty(struct uart_port * port)358 static 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
max3100_get_mctrl(struct uart_port * port)369 static 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
max3100_set_mctrl(struct uart_port * port,unsigned int mctrl)381 static 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
405 static void
max3100_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)406 max3100_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
max3100_shutdown(struct uart_port * port)523 static 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
max3100_startup(struct uart_port * port)548 static 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
max3100_type(struct uart_port * port)594 static 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
max3100_release_port(struct uart_port * port)603 static 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
max3100_config_port(struct uart_port * port,int flags)610 static 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
max3100_verify_port(struct uart_port * port,struct serial_struct * ser)620 static 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
max3100_stop_tx(struct uart_port * port)633 static 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
max3100_request_port(struct uart_port * port)640 static 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
max3100_break_ctl(struct uart_port * port,int break_state)648 static 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
655 static 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
674 static 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 };
682 static int uart_driver_registered;
683
max3100_probe(struct spi_device * spi)684 static 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
max3100_remove(struct spi_device * spi)743 static 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
max3100_suspend(struct device * dev)775 static 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
max3100_resume(struct device * dev)792 static 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
810 static DEFINE_SIMPLE_DEV_PM_OPS(max3100_pm_ops, max3100_suspend, max3100_resume);
811
812 static const struct spi_device_id max3100_spi_id[] = {
813 { "max3100" },
814 { }
815 };
816 MODULE_DEVICE_TABLE(spi, max3100_spi_id);
817
818 static const struct of_device_id max3100_of_match[] = {
819 { .compatible = "maxim,max3100" },
820 { }
821 };
822 MODULE_DEVICE_TABLE(of, max3100_of_match);
823
824 static 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
835 module_spi_driver(max3100_driver);
836
837 MODULE_DESCRIPTION("MAX3100 driver");
838 MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
839 MODULE_LICENSE("GPL");
840