xref: /openbmc/linux/drivers/tty/serial/max3100.c (revision 565d76cb)
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 
94 struct 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 
138 static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
139 static DEFINE_MUTEX(max3100s_lock);		   /* race on probe */
140 
141 static 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 
159 static int max3100_check_parity(struct max3100_port *s, u16 c)
160 {
161 	return max3100_do_parity(s, c) == ((c >> 8) & 1);
162 }
163 
164 static 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 
175 static void max3100_work(struct work_struct *w);
176 
177 static 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 
184 static 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 
194 static 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 
219 static 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 
259 static 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 
328 static 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 
338 static 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 
349 static 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 
360 static 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 
376 static 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 
389 static 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 
403 static 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 
423 static void
424 max3100_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 
548 static 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 
583 static 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 
638 static 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 
649 static 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 
658 static 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 
670 static 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 
685 static 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 
694 static 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 
704 static 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 
713 static 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 
732 static 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 };
740 static int uart_driver_registered;
741 
742 static 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 
818 static 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 
850 static 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 
873 static 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 
898 static 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 
911 static int __init max3100_init(void)
912 {
913 	return spi_register_driver(&max3100_driver);
914 }
915 module_init(max3100_init);
916 
917 static void __exit max3100_exit(void)
918 {
919 	spi_unregister_driver(&max3100_driver);
920 }
921 module_exit(max3100_exit);
922 
923 MODULE_DESCRIPTION("MAX3100 driver");
924 MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
925 MODULE_LICENSE("GPL");
926 MODULE_ALIAS("spi:max3100");
927