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/drivers/tty/serial/max3100.c

http://github.com/mirrors/linux
C | 909 lines | 708 code | 150 blank | 51 comment | 88 complexity | 53545aeb62ff1ab3dad50a940b889e87 MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 *
  4 *  Copyright (C) 2008 Christian Pellegrin <chripell@evolware.org>
  5 *
  6 * Notes: the MAX3100 doesn't provide an interrupt on CTS so we have
  7 * to use polling for flow control. TX empty IRQ is unusable, since
  8 * writing conf clears FIFO buffer and we cannot have this interrupt
  9 * always asking us for attention.
 10 *
 11 * Example platform data:
 12
 13 static struct plat_max3100 max3100_plat_data = {
 14 .loopback = 0,
 15 .crystal = 0,
 16 .poll_time = 100,
 17 };
 18
 19 static struct spi_board_info spi_board_info[] = {
 20 {
 21 .modalias	= "max3100",
 22 .platform_data	= &max3100_plat_data,
 23 .irq		= IRQ_EINT12,
 24 .max_speed_hz	= 5*1000*1000,
 25 .chip_select	= 0,
 26 },
 27 };
 28
 29 * The initial minor number is 209 in the low-density serial port:
 30 * mknod /dev/ttyMAX0 c 204 209
 31 */
 32
 33#define MAX3100_MAJOR 204
 34#define MAX3100_MINOR 209
 35/* 4 MAX3100s should be enough for everyone */
 36#define MAX_MAX3100 4
 37
 38#include <linux/delay.h>
 39#include <linux/slab.h>
 40#include <linux/device.h>
 41#include <linux/module.h>
 42#include <linux/serial_core.h>
 43#include <linux/serial.h>
 44#include <linux/spi/spi.h>
 45#include <linux/freezer.h>
 46#include <linux/tty.h>
 47#include <linux/tty_flip.h>
 48
 49#include <linux/serial_max3100.h>
 50
 51#define MAX3100_C    (1<<14)
 52#define MAX3100_D    (0<<14)
 53#define MAX3100_W    (1<<15)
 54#define MAX3100_RX   (0<<15)
 55
 56#define MAX3100_WC   (MAX3100_W  | MAX3100_C)
 57#define MAX3100_RC   (MAX3100_RX | MAX3100_C)
 58#define MAX3100_WD   (MAX3100_W  | MAX3100_D)
 59#define MAX3100_RD   (MAX3100_RX | MAX3100_D)
 60#define MAX3100_CMD  (3 << 14)
 61
 62#define MAX3100_T    (1<<14)
 63#define MAX3100_R    (1<<15)
 64
 65#define MAX3100_FEN  (1<<13)
 66#define MAX3100_SHDN (1<<12)
 67#define MAX3100_TM   (1<<11)
 68#define MAX3100_RM   (1<<10)
 69#define MAX3100_PM   (1<<9)
 70#define MAX3100_RAM  (1<<8)
 71#define MAX3100_IR   (1<<7)
 72#define MAX3100_ST   (1<<6)
 73#define MAX3100_PE   (1<<5)
 74#define MAX3100_L    (1<<4)
 75#define MAX3100_BAUD (0xf)
 76
 77#define MAX3100_TE   (1<<10)
 78#define MAX3100_RAFE (1<<10)
 79#define MAX3100_RTS  (1<<9)
 80#define MAX3100_CTS  (1<<9)
 81#define MAX3100_PT   (1<<8)
 82#define MAX3100_DATA (0xff)
 83
 84#define MAX3100_RT   (MAX3100_R | MAX3100_T)
 85#define MAX3100_RTC  (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE)
 86
 87/* the following simulate a status reg for ignore_status_mask */
 88#define MAX3100_STATUS_PE 1
 89#define MAX3100_STATUS_FE 2
 90#define MAX3100_STATUS_OE 4
 91
 92struct max3100_port {
 93	struct uart_port port;
 94	struct spi_device *spi;
 95
 96	int cts;	        /* last CTS received for flow ctrl */
 97	int tx_empty;		/* last TX empty bit */
 98
 99	spinlock_t conf_lock;	/* shared data */
100	int conf_commit;	/* need to make changes */
101	int conf;		/* configuration for the MAX31000
102				 * (bits 0-7, bits 8-11 are irqs) */
103	int rts_commit;	        /* need to change rts */
104	int rts;		/* rts status */
105	int baud;		/* current baud rate */
106
107	int parity;		/* keeps track if we should send parity */
108#define MAX3100_PARITY_ON 1
109#define MAX3100_PARITY_ODD 2
110#define MAX3100_7BIT 4
111	int rx_enabled;	        /* if we should rx chars */
112
113	int irq;		/* irq assigned to the max3100 */
114
115	int minor;		/* minor number */
116	int crystal;		/* 1 if 3.6864Mhz crystal 0 for 1.8432 */
117	int loopback;		/* 1 if we are in loopback mode */
118
119	/* for handling irqs: need workqueue since we do spi_sync */
120	struct workqueue_struct *workqueue;
121	struct work_struct work;
122	/* set to 1 to make the workhandler exit as soon as possible */
123	int  force_end_work;
124	/* need to know we are suspending to avoid deadlock on workqueue */
125	int suspending;
126
127	/* hook for suspending MAX3100 via dedicated pin */
128	void (*max3100_hw_suspend) (int suspend);
129
130	/* poll time (in ms) for ctrl lines */
131	int poll_time;
132	/* and its timer */
133	struct timer_list	timer;
134};
135
136static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
137static DEFINE_MUTEX(max3100s_lock);		   /* race on probe */
138
139static int max3100_do_parity(struct max3100_port *s, u16 c)
140{
141	int parity;
142
143	if (s->parity & MAX3100_PARITY_ODD)
144		parity = 1;
145	else
146		parity = 0;
147
148	if (s->parity & MAX3100_7BIT)
149		c &= 0x7f;
150	else
151		c &= 0xff;
152
153	parity = parity ^ (hweight8(c) & 1);
154	return parity;
155}
156
157static int max3100_check_parity(struct max3100_port *s, u16 c)
158{
159	return max3100_do_parity(s, c) == ((c >> 8) & 1);
160}
161
162static void max3100_calc_parity(struct max3100_port *s, u16 *c)
163{
164	if (s->parity & MAX3100_7BIT)
165		*c &= 0x7f;
166	else
167		*c &= 0xff;
168
169	if (s->parity & MAX3100_PARITY_ON)
170		*c |= max3100_do_parity(s, *c) << 8;
171}
172
173static void max3100_work(struct work_struct *w);
174
175static void max3100_dowork(struct max3100_port *s)
176{
177	if (!s->force_end_work && !freezing(current) && !s->suspending)
178		queue_work(s->workqueue, &s->work);
179}
180
181static void max3100_timeout(struct timer_list *t)
182{
183	struct max3100_port *s = from_timer(s, t, timer);
184
185	if (s->port.state) {
186		max3100_dowork(s);
187		mod_timer(&s->timer, jiffies + s->poll_time);
188	}
189}
190
191static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx)
192{
193	struct spi_message message;
194	u16 etx, erx;
195	int status;
196	struct spi_transfer tran = {
197		.tx_buf = &etx,
198		.rx_buf = &erx,
199		.len = 2,
200	};
201
202	etx = cpu_to_be16(tx);
203	spi_message_init(&message);
204	spi_message_add_tail(&tran, &message);
205	status = spi_sync(s->spi, &message);
206	if (status) {
207		dev_warn(&s->spi->dev, "error while calling spi_sync\n");
208		return -EIO;
209	}
210	*rx = be16_to_cpu(erx);
211	s->tx_empty = (*rx & MAX3100_T) > 0;
212	dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
213	return 0;
214}
215
216static int max3100_handlerx(struct max3100_port *s, u16 rx)
217{
218	unsigned int ch, flg, status = 0;
219	int ret = 0, cts;
220
221	if (rx & MAX3100_R && s->rx_enabled) {
222		dev_dbg(&s->spi->dev, "%s\n", __func__);
223		ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff);
224		if (rx & MAX3100_RAFE) {
225			s->port.icount.frame++;
226			flg = TTY_FRAME;
227			status |= MAX3100_STATUS_FE;
228		} else {
229			if (s->parity & MAX3100_PARITY_ON) {
230				if (max3100_check_parity(s, rx)) {
231					s->port.icount.rx++;
232					flg = TTY_NORMAL;
233				} else {
234					s->port.icount.parity++;
235					flg = TTY_PARITY;
236					status |= MAX3100_STATUS_PE;
237				}
238			} else {
239				s->port.icount.rx++;
240				flg = TTY_NORMAL;
241			}
242		}
243		uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg);
244		ret = 1;
245	}
246
247	cts = (rx & MAX3100_CTS) > 0;
248	if (s->cts != cts) {
249		s->cts = cts;
250		uart_handle_cts_change(&s->port, cts ? TIOCM_CTS : 0);
251	}
252
253	return ret;
254}
255
256static void max3100_work(struct work_struct *w)
257{
258	struct max3100_port *s = container_of(w, struct max3100_port, work);
259	int rxchars;
260	u16 tx, rx;
261	int conf, cconf, crts;
262	struct circ_buf *xmit = &s->port.state->xmit;
263
264	dev_dbg(&s->spi->dev, "%s\n", __func__);
265
266	rxchars = 0;
267	do {
268		spin_lock(&s->conf_lock);
269		conf = s->conf;
270		cconf = s->conf_commit;
271		s->conf_commit = 0;
272		crts = s->rts_commit;
273		s->rts_commit = 0;
274		spin_unlock(&s->conf_lock);
275		if (cconf)
276			max3100_sr(s, MAX3100_WC | conf, &rx);
277		if (crts) {
278			max3100_sr(s, MAX3100_WD | MAX3100_TE |
279				   (s->rts ? MAX3100_RTS : 0), &rx);
280			rxchars += max3100_handlerx(s, rx);
281		}
282
283		max3100_sr(s, MAX3100_RD, &rx);
284		rxchars += max3100_handlerx(s, rx);
285
286		if (rx & MAX3100_T) {
287			tx = 0xffff;
288			if (s->port.x_char) {
289				tx = s->port.x_char;
290				s->port.icount.tx++;
291				s->port.x_char = 0;
292			} else if (!uart_circ_empty(xmit) &&
293				   !uart_tx_stopped(&s->port)) {
294				tx = xmit->buf[xmit->tail];
295				xmit->tail = (xmit->tail + 1) &
296					(UART_XMIT_SIZE - 1);
297				s->port.icount.tx++;
298			}
299			if (tx != 0xffff) {
300				max3100_calc_parity(s, &tx);
301				tx |= MAX3100_WD | (s->rts ? MAX3100_RTS : 0);
302				max3100_sr(s, tx, &rx);
303				rxchars += max3100_handlerx(s, rx);
304			}
305		}
306
307		if (rxchars > 16) {
308			tty_flip_buffer_push(&s->port.state->port);
309			rxchars = 0;
310		}
311		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
312			uart_write_wakeup(&s->port);
313
314	} while (!s->force_end_work &&
315		 !freezing(current) &&
316		 ((rx & MAX3100_R) ||
317		  (!uart_circ_empty(xmit) &&
318		   !uart_tx_stopped(&s->port))));
319
320	if (rxchars > 0)
321		tty_flip_buffer_push(&s->port.state->port);
322}
323
324static irqreturn_t max3100_irq(int irqno, void *dev_id)
325{
326	struct max3100_port *s = dev_id;
327
328	dev_dbg(&s->spi->dev, "%s\n", __func__);
329
330	max3100_dowork(s);
331	return IRQ_HANDLED;
332}
333
334static void max3100_enable_ms(struct uart_port *port)
335{
336	struct max3100_port *s = container_of(port,
337					      struct max3100_port,
338					      port);
339
340	if (s->poll_time > 0)
341		mod_timer(&s->timer, jiffies);
342	dev_dbg(&s->spi->dev, "%s\n", __func__);
343}
344
345static void max3100_start_tx(struct uart_port *port)
346{
347	struct max3100_port *s = container_of(port,
348					      struct max3100_port,
349					      port);
350
351	dev_dbg(&s->spi->dev, "%s\n", __func__);
352
353	max3100_dowork(s);
354}
355
356static void max3100_stop_rx(struct uart_port *port)
357{
358	struct max3100_port *s = container_of(port,
359					      struct max3100_port,
360					      port);
361
362	dev_dbg(&s->spi->dev, "%s\n", __func__);
363
364	s->rx_enabled = 0;
365	spin_lock(&s->conf_lock);
366	s->conf &= ~MAX3100_RM;
367	s->conf_commit = 1;
368	spin_unlock(&s->conf_lock);
369	max3100_dowork(s);
370}
371
372static unsigned int max3100_tx_empty(struct uart_port *port)
373{
374	struct max3100_port *s = container_of(port,
375					      struct max3100_port,
376					      port);
377
378	dev_dbg(&s->spi->dev, "%s\n", __func__);
379
380	/* may not be truly up-to-date */
381	max3100_dowork(s);
382	return s->tx_empty;
383}
384
385static unsigned int max3100_get_mctrl(struct uart_port *port)
386{
387	struct max3100_port *s = container_of(port,
388					      struct max3100_port,
389					      port);
390
391	dev_dbg(&s->spi->dev, "%s\n", __func__);
392
393	/* may not be truly up-to-date */
394	max3100_dowork(s);
395	/* always assert DCD and DSR since these lines are not wired */
396	return (s->cts ? TIOCM_CTS : 0) | TIOCM_DSR | TIOCM_CAR;
397}
398
399static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl)
400{
401	struct max3100_port *s = container_of(port,
402					      struct max3100_port,
403					      port);
404	int rts;
405
406	dev_dbg(&s->spi->dev, "%s\n", __func__);
407
408	rts = (mctrl & TIOCM_RTS) > 0;
409
410	spin_lock(&s->conf_lock);
411	if (s->rts != rts) {
412		s->rts = rts;
413		s->rts_commit = 1;
414		max3100_dowork(s);
415	}
416	spin_unlock(&s->conf_lock);
417}
418
419static void
420max3100_set_termios(struct uart_port *port, struct ktermios *termios,
421		    struct ktermios *old)
422{
423	struct max3100_port *s = container_of(port,
424					      struct max3100_port,
425					      port);
426	int baud = 0;
427	unsigned cflag;
428	u32 param_new, param_mask, parity = 0;
429
430	dev_dbg(&s->spi->dev, "%s\n", __func__);
431
432	cflag = termios->c_cflag;
433	param_mask = 0;
434
435	baud = tty_termios_baud_rate(termios);
436	param_new = s->conf & MAX3100_BAUD;
437	switch (baud) {
438	case 300:
439		if (s->crystal)
440			baud = s->baud;
441		else
442			param_new = 15;
443		break;
444	case 600:
445		param_new = 14 + s->crystal;
446		break;
447	case 1200:
448		param_new = 13 + s->crystal;
449		break;
450	case 2400:
451		param_new = 12 + s->crystal;
452		break;
453	case 4800:
454		param_new = 11 + s->crystal;
455		break;
456	case 9600:
457		param_new = 10 + s->crystal;
458		break;
459	case 19200:
460		param_new = 9 + s->crystal;
461		break;
462	case 38400:
463		param_new = 8 + s->crystal;
464		break;
465	case 57600:
466		param_new = 1 + s->crystal;
467		break;
468	case 115200:
469		param_new = 0 + s->crystal;
470		break;
471	case 230400:
472		if (s->crystal)
473			param_new = 0;
474		else
475			baud = s->baud;
476		break;
477	default:
478		baud = s->baud;
479	}
480	tty_termios_encode_baud_rate(termios, baud, baud);
481	s->baud = baud;
482	param_mask |= MAX3100_BAUD;
483
484	if ((cflag & CSIZE) == CS8) {
485		param_new &= ~MAX3100_L;
486		parity &= ~MAX3100_7BIT;
487	} else {
488		param_new |= MAX3100_L;
489		parity |= MAX3100_7BIT;
490		cflag = (cflag & ~CSIZE) | CS7;
491	}
492	param_mask |= MAX3100_L;
493
494	if (cflag & CSTOPB)
495		param_new |= MAX3100_ST;
496	else
497		param_new &= ~MAX3100_ST;
498	param_mask |= MAX3100_ST;
499
500	if (cflag & PARENB) {
501		param_new |= MAX3100_PE;
502		parity |= MAX3100_PARITY_ON;
503	} else {
504		param_new &= ~MAX3100_PE;
505		parity &= ~MAX3100_PARITY_ON;
506	}
507	param_mask |= MAX3100_PE;
508
509	if (cflag & PARODD)
510		parity |= MAX3100_PARITY_ODD;
511	else
512		parity &= ~MAX3100_PARITY_ODD;
513
514	/* mask termios capabilities we don't support */
515	cflag &= ~CMSPAR;
516	termios->c_cflag = cflag;
517
518	s->port.ignore_status_mask = 0;
519	if (termios->c_iflag & IGNPAR)
520		s->port.ignore_status_mask |=
521			MAX3100_STATUS_PE | MAX3100_STATUS_FE |
522			MAX3100_STATUS_OE;
523
524	/* we are sending char from a workqueue so enable */
525	s->port.state->port.low_latency = 1;
526
527	if (s->poll_time > 0)
528		del_timer_sync(&s->timer);
529
530	uart_update_timeout(port, termios->c_cflag, baud);
531
532	spin_lock(&s->conf_lock);
533	s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
534	s->conf_commit = 1;
535	s->parity = parity;
536	spin_unlock(&s->conf_lock);
537	max3100_dowork(s);
538
539	if (UART_ENABLE_MS(&s->port, termios->c_cflag))
540		max3100_enable_ms(&s->port);
541}
542
543static void max3100_shutdown(struct uart_port *port)
544{
545	struct max3100_port *s = container_of(port,
546					      struct max3100_port,
547					      port);
548
549	dev_dbg(&s->spi->dev, "%s\n", __func__);
550
551	if (s->suspending)
552		return;
553
554	s->force_end_work = 1;
555
556	if (s->poll_time > 0)
557		del_timer_sync(&s->timer);
558
559	if (s->workqueue) {
560		flush_workqueue(s->workqueue);
561		destroy_workqueue(s->workqueue);
562		s->workqueue = NULL;
563	}
564	if (s->irq)
565		free_irq(s->irq, s);
566
567	/* set shutdown mode to save power */
568	if (s->max3100_hw_suspend)
569		s->max3100_hw_suspend(1);
570	else  {
571		u16 tx, rx;
572
573		tx = MAX3100_WC | MAX3100_SHDN;
574		max3100_sr(s, tx, &rx);
575	}
576}
577
578static int max3100_startup(struct uart_port *port)
579{
580	struct max3100_port *s = container_of(port,
581					      struct max3100_port,
582					      port);
583	char b[12];
584
585	dev_dbg(&s->spi->dev, "%s\n", __func__);
586
587	s->conf = MAX3100_RM;
588	s->baud = s->crystal ? 230400 : 115200;
589	s->rx_enabled = 1;
590
591	if (s->suspending)
592		return 0;
593
594	s->force_end_work = 0;
595	s->parity = 0;
596	s->rts = 0;
597
598	sprintf(b, "max3100-%d", s->minor);
599	s->workqueue = create_freezable_workqueue(b);
600	if (!s->workqueue) {
601		dev_warn(&s->spi->dev, "cannot create workqueue\n");
602		return -EBUSY;
603	}
604	INIT_WORK(&s->work, max3100_work);
605
606	if (request_irq(s->irq, max3100_irq,
607			IRQF_TRIGGER_FALLING, "max3100", s) < 0) {
608		dev_warn(&s->spi->dev, "cannot allocate irq %d\n", s->irq);
609		s->irq = 0;
610		destroy_workqueue(s->workqueue);
611		s->workqueue = NULL;
612		return -EBUSY;
613	}
614
615	if (s->loopback) {
616		u16 tx, rx;
617		tx = 0x4001;
618		max3100_sr(s, tx, &rx);
619	}
620
621	if (s->max3100_hw_suspend)
622		s->max3100_hw_suspend(0);
623	s->conf_commit = 1;
624	max3100_dowork(s);
625	/* wait for clock to settle */
626	msleep(50);
627
628	max3100_enable_ms(&s->port);
629
630	return 0;
631}
632
633static const char *max3100_type(struct uart_port *port)
634{
635	struct max3100_port *s = container_of(port,
636					      struct max3100_port,
637					      port);
638
639	dev_dbg(&s->spi->dev, "%s\n", __func__);
640
641	return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL;
642}
643
644static void max3100_release_port(struct uart_port *port)
645{
646	struct max3100_port *s = container_of(port,
647					      struct max3100_port,
648					      port);
649
650	dev_dbg(&s->spi->dev, "%s\n", __func__);
651}
652
653static void max3100_config_port(struct uart_port *port, int flags)
654{
655	struct max3100_port *s = container_of(port,
656					      struct max3100_port,
657					      port);
658
659	dev_dbg(&s->spi->dev, "%s\n", __func__);
660
661	if (flags & UART_CONFIG_TYPE)
662		s->port.type = PORT_MAX3100;
663}
664
665static int max3100_verify_port(struct uart_port *port,
666			       struct serial_struct *ser)
667{
668	struct max3100_port *s = container_of(port,
669					      struct max3100_port,
670					      port);
671	int ret = -EINVAL;
672
673	dev_dbg(&s->spi->dev, "%s\n", __func__);
674
675	if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100)
676		ret = 0;
677	return ret;
678}
679
680static void max3100_stop_tx(struct uart_port *port)
681{
682	struct max3100_port *s = container_of(port,
683					      struct max3100_port,
684					      port);
685
686	dev_dbg(&s->spi->dev, "%s\n", __func__);
687}
688
689static int max3100_request_port(struct uart_port *port)
690{
691	struct max3100_port *s = container_of(port,
692					      struct max3100_port,
693					      port);
694
695	dev_dbg(&s->spi->dev, "%s\n", __func__);
696	return 0;
697}
698
699static void max3100_break_ctl(struct uart_port *port, int break_state)
700{
701	struct max3100_port *s = container_of(port,
702					      struct max3100_port,
703					      port);
704
705	dev_dbg(&s->spi->dev, "%s\n", __func__);
706}
707
708static const struct uart_ops max3100_ops = {
709	.tx_empty	= max3100_tx_empty,
710	.set_mctrl	= max3100_set_mctrl,
711	.get_mctrl	= max3100_get_mctrl,
712	.stop_tx        = max3100_stop_tx,
713	.start_tx	= max3100_start_tx,
714	.stop_rx	= max3100_stop_rx,
715	.enable_ms      = max3100_enable_ms,
716	.break_ctl      = max3100_break_ctl,
717	.startup	= max3100_startup,
718	.shutdown	= max3100_shutdown,
719	.set_termios	= max3100_set_termios,
720	.type		= max3100_type,
721	.release_port   = max3100_release_port,
722	.request_port   = max3100_request_port,
723	.config_port	= max3100_config_port,
724	.verify_port	= max3100_verify_port,
725};
726
727static struct uart_driver max3100_uart_driver = {
728	.owner          = THIS_MODULE,
729	.driver_name    = "ttyMAX",
730	.dev_name       = "ttyMAX",
731	.major          = MAX3100_MAJOR,
732	.minor          = MAX3100_MINOR,
733	.nr             = MAX_MAX3100,
734};
735static int uart_driver_registered;
736
737static int max3100_probe(struct spi_device *spi)
738{
739	int i, retval;
740	struct plat_max3100 *pdata;
741	u16 tx, rx;
742
743	mutex_lock(&max3100s_lock);
744
745	if (!uart_driver_registered) {
746		uart_driver_registered = 1;
747		retval = uart_register_driver(&max3100_uart_driver);
748		if (retval) {
749			printk(KERN_ERR "Couldn't register max3100 uart driver\n");
750			mutex_unlock(&max3100s_lock);
751			return retval;
752		}
753	}
754
755	for (i = 0; i < MAX_MAX3100; i++)
756		if (!max3100s[i])
757			break;
758	if (i == MAX_MAX3100) {
759		dev_warn(&spi->dev, "too many MAX3100 chips\n");
760		mutex_unlock(&max3100s_lock);
761		return -ENOMEM;
762	}
763
764	max3100s[i] = kzalloc(sizeof(struct max3100_port), GFP_KERNEL);
765	if (!max3100s[i]) {
766		dev_warn(&spi->dev,
767			 "kmalloc for max3100 structure %d failed!\n", i);
768		mutex_unlock(&max3100s_lock);
769		return -ENOMEM;
770	}
771	max3100s[i]->spi = spi;
772	max3100s[i]->irq = spi->irq;
773	spin_lock_init(&max3100s[i]->conf_lock);
774	spi_set_drvdata(spi, max3100s[i]);
775	pdata = dev_get_platdata(&spi->dev);
776	max3100s[i]->crystal = pdata->crystal;
777	max3100s[i]->loopback = pdata->loopback;
778	max3100s[i]->poll_time = msecs_to_jiffies(pdata->poll_time);
779	if (pdata->poll_time > 0 && max3100s[i]->poll_time == 0)
780		max3100s[i]->poll_time = 1;
781	max3100s[i]->max3100_hw_suspend = pdata->max3100_hw_suspend;
782	max3100s[i]->minor = i;
783	timer_setup(&max3100s[i]->timer, max3100_timeout, 0);
784
785	dev_dbg(&spi->dev, "%s: adding port %d\n", __func__, i);
786	max3100s[i]->port.irq = max3100s[i]->irq;
787	max3100s[i]->port.uartclk = max3100s[i]->crystal ? 3686400 : 1843200;
788	max3100s[i]->port.fifosize = 16;
789	max3100s[i]->port.ops = &max3100_ops;
790	max3100s[i]->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
791	max3100s[i]->port.line = i;
792	max3100s[i]->port.type = PORT_MAX3100;
793	max3100s[i]->port.dev = &spi->dev;
794	retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port);
795	if (retval < 0)
796		dev_warn(&spi->dev,
797			 "uart_add_one_port failed for line %d with error %d\n",
798			 i, retval);
799
800	/* set shutdown mode to save power. Will be woken-up on open */
801	if (max3100s[i]->max3100_hw_suspend)
802		max3100s[i]->max3100_hw_suspend(1);
803	else {
804		tx = MAX3100_WC | MAX3100_SHDN;
805		max3100_sr(max3100s[i], tx, &rx);
806	}
807	mutex_unlock(&max3100s_lock);
808	return 0;
809}
810
811static int max3100_remove(struct spi_device *spi)
812{
813	struct max3100_port *s = spi_get_drvdata(spi);
814	int i;
815
816	mutex_lock(&max3100s_lock);
817
818	/* find out the index for the chip we are removing */
819	for (i = 0; i < MAX_MAX3100; i++)
820		if (max3100s[i] == s) {
821			dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i);
822			uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port);
823			kfree(max3100s[i]);
824			max3100s[i] = NULL;
825			break;
826		}
827
828	WARN_ON(i == MAX_MAX3100);
829	
830	/* check if this is the last chip we have */
831	for (i = 0; i < MAX_MAX3100; i++)
832		if (max3100s[i]) {
833			mutex_unlock(&max3100s_lock);
834			return 0;
835		}
836	pr_debug("removing max3100 driver\n");
837	uart_unregister_driver(&max3100_uart_driver);
838
839	mutex_unlock(&max3100s_lock);
840	return 0;
841}
842
843#ifdef CONFIG_PM_SLEEP
844
845static int max3100_suspend(struct device *dev)
846{
847	struct max3100_port *s = dev_get_drvdata(dev);
848
849	dev_dbg(&s->spi->dev, "%s\n", __func__);
850
851	disable_irq(s->irq);
852
853	s->suspending = 1;
854	uart_suspend_port(&max3100_uart_driver, &s->port);
855
856	if (s->max3100_hw_suspend)
857		s->max3100_hw_suspend(1);
858	else {
859		/* no HW suspend, so do SW one */
860		u16 tx, rx;
861
862		tx = MAX3100_WC | MAX3100_SHDN;
863		max3100_sr(s, tx, &rx);
864	}
865	return 0;
866}
867
868static int max3100_resume(struct device *dev)
869{
870	struct max3100_port *s = dev_get_drvdata(dev);
871
872	dev_dbg(&s->spi->dev, "%s\n", __func__);
873
874	if (s->max3100_hw_suspend)
875		s->max3100_hw_suspend(0);
876	uart_resume_port(&max3100_uart_driver, &s->port);
877	s->suspending = 0;
878
879	enable_irq(s->irq);
880
881	s->conf_commit = 1;
882	if (s->workqueue)
883		max3100_dowork(s);
884
885	return 0;
886}
887
888static SIMPLE_DEV_PM_OPS(max3100_pm_ops, max3100_suspend, max3100_resume);
889#define MAX3100_PM_OPS (&max3100_pm_ops)
890
891#else
892#define MAX3100_PM_OPS NULL
893#endif
894
895static struct spi_driver max3100_driver = {
896	.driver = {
897		.name		= "max3100",
898		.pm		= MAX3100_PM_OPS,
899	},
900	.probe		= max3100_probe,
901	.remove		= max3100_remove,
902};
903
904module_spi_driver(max3100_driver);
905
906MODULE_DESCRIPTION("MAX3100 driver");
907MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
908MODULE_LICENSE("GPL");
909MODULE_ALIAS("spi:max3100");