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/module.h>
47#include <linux/serial_core.h>
48#include <linux/serial.h>
49#include <linux/spi/spi.h>
50#include <linux/freezer.h>
51#include <linux/tty.h>
52#include <linux/tty_flip.h>
53
54#include <linux/serial_max3100.h>
55
56#define MAX3100_C    (1<<14)
57#define MAX3100_D    (0<<14)
58#define MAX3100_W    (1<<15)
59#define MAX3100_RX   (0<<15)
60
61#define MAX3100_WC   (MAX3100_W  | MAX3100_C)
62#define MAX3100_RC   (MAX3100_RX | MAX3100_C)
63#define MAX3100_WD   (MAX3100_W  | MAX3100_D)
64#define MAX3100_RD   (MAX3100_RX | MAX3100_D)
65#define MAX3100_CMD  (3 << 14)
66
67#define MAX3100_T    (1<<14)
68#define MAX3100_R    (1<<15)
69
70#define MAX3100_FEN  (1<<13)
71#define MAX3100_SHDN (1<<12)
72#define MAX3100_TM   (1<<11)
73#define MAX3100_RM   (1<<10)
74#define MAX3100_PM   (1<<9)
75#define MAX3100_RAM  (1<<8)
76#define MAX3100_IR   (1<<7)
77#define MAX3100_ST   (1<<6)
78#define MAX3100_PE   (1<<5)
79#define MAX3100_L    (1<<4)
80#define MAX3100_BAUD (0xf)
81
82#define MAX3100_TE   (1<<10)
83#define MAX3100_RAFE (1<<10)
84#define MAX3100_RTS  (1<<9)
85#define MAX3100_CTS  (1<<9)
86#define MAX3100_PT   (1<<8)
87#define MAX3100_DATA (0xff)
88
89#define MAX3100_RT   (MAX3100_R | MAX3100_T)
90#define MAX3100_RTC  (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE)
91
92/* the following simulate a status reg for ignore_status_mask */
93#define MAX3100_STATUS_PE 1
94#define MAX3100_STATUS_FE 2
95#define MAX3100_STATUS_OE 4
96
97struct max3100_port {
98	struct uart_port port;
99	struct spi_device *spi;
100
101	int cts;	        /* last CTS received for flow ctrl */
102	int tx_empty;		/* last TX empty bit */
103
104	spinlock_t conf_lock;	/* shared data */
105	int conf_commit;	/* need to make changes */
106	int conf;		/* configuration for the MAX31000
107				 * (bits 0-7, bits 8-11 are irqs) */
108	int rts_commit;	        /* need to change rts */
109	int rts;		/* rts status */
110	int baud;		/* current baud rate */
111
112	int parity;		/* keeps track if we should send parity */
113#define MAX3100_PARITY_ON 1
114#define MAX3100_PARITY_ODD 2
115#define MAX3100_7BIT 4
116	int rx_enabled;	        /* if we should rx chars */
117
118	int irq;		/* irq assigned to the max3100 */
119
120	int minor;		/* minor number */
121	int crystal;		/* 1 if 3.6864Mhz crystal 0 for 1.8432 */
122	int loopback;		/* 1 if we are in loopback mode */
123
124	/* for handling irqs: need workqueue since we do spi_sync */
125	struct workqueue_struct *workqueue;
126	struct work_struct work;
127	/* set to 1 to make the workhandler exit as soon as possible */
128	int  force_end_work;
129	/* need to know we are suspending to avoid deadlock on workqueue */
130	int suspending;
131
132	/* hook for suspending MAX3100 via dedicated pin */
133	void (*max3100_hw_suspend) (int suspend);
134
135	/* poll time (in ms) for ctrl lines */
136	int poll_time;
137	/* and its timer */
138	struct timer_list	timer;
139};
140
141static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
142static DEFINE_MUTEX(max3100s_lock);		   /* race on probe */
143
144static int max3100_do_parity(struct max3100_port *s, u16 c)
145{
146	int parity;
147
148	if (s->parity & MAX3100_PARITY_ODD)
149		parity = 1;
150	else
151		parity = 0;
152
153	if (s->parity & MAX3100_7BIT)
154		c &= 0x7f;
155	else
156		c &= 0xff;
157
158	parity = parity ^ (hweight8(c) & 1);
159	return parity;
160}
161
162static int max3100_check_parity(struct max3100_port *s, u16 c)
163{
164	return max3100_do_parity(s, c) == ((c >> 8) & 1);
165}
166
167static void max3100_calc_parity(struct max3100_port *s, u16 *c)
168{
169	if (s->parity & MAX3100_7BIT)
170		*c &= 0x7f;
171	else
172		*c &= 0xff;
173
174	if (s->parity & MAX3100_PARITY_ON)
175		*c |= max3100_do_parity(s, *c) << 8;
176}
177
178static void max3100_work(struct work_struct *w);
179
180static void max3100_dowork(struct max3100_port *s)
181{
182	if (!s->force_end_work && !freezing(current) && !s->suspending)
183		queue_work(s->workqueue, &s->work);
184}
185
186static void max3100_timeout(unsigned long data)
187{
188	struct max3100_port *s = (struct max3100_port *)data;
189
190	if (s->port.state) {
191		max3100_dowork(s);
192		mod_timer(&s->timer, jiffies + s->poll_time);
193	}
194}
195
196static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx)
197{
198	struct spi_message message;
199	u16 etx, erx;
200	int status;
201	struct spi_transfer tran = {
202		.tx_buf = &etx,
203		.rx_buf = &erx,
204		.len = 2,
205	};
206
207	etx = cpu_to_be16(tx);
208	spi_message_init(&message);
209	spi_message_add_tail(&tran, &message);
210	status = spi_sync(s->spi, &message);
211	if (status) {
212		dev_warn(&s->spi->dev, "error while calling spi_sync\n");
213		return -EIO;
214	}
215	*rx = be16_to_cpu(erx);
216	s->tx_empty = (*rx & MAX3100_T) > 0;
217	dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
218	return 0;
219}
220
221static int max3100_handlerx(struct max3100_port *s, u16 rx)
222{
223	unsigned int ch, flg, status = 0;
224	int ret = 0, cts;
225
226	if (rx & MAX3100_R && s->rx_enabled) {
227		dev_dbg(&s->spi->dev, "%s\n", __func__);
228		ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff);
229		if (rx & MAX3100_RAFE) {
230			s->port.icount.frame++;
231			flg = TTY_FRAME;
232			status |= MAX3100_STATUS_FE;
233		} else {
234			if (s->parity & MAX3100_PARITY_ON) {
235				if (max3100_check_parity(s, rx)) {
236					s->port.icount.rx++;
237					flg = TTY_NORMAL;
238				} else {
239					s->port.icount.parity++;
240					flg = TTY_PARITY;
241					status |= MAX3100_STATUS_PE;
242				}
243			} else {
244				s->port.icount.rx++;
245				flg = TTY_NORMAL;
246			}
247		}
248		uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg);
249		ret = 1;
250	}
251
252	cts = (rx & MAX3100_CTS) > 0;
253	if (s->cts != cts) {
254		s->cts = cts;
255		uart_handle_cts_change(&s->port, cts ? TIOCM_CTS : 0);
256	}
257
258	return ret;
259}
260
261static void max3100_work(struct work_struct *w)
262{
263	struct max3100_port *s = container_of(w, struct max3100_port, work);
264	int rxchars;
265	u16 tx, rx;
266	int conf, cconf, rts, crts;
267	struct circ_buf *xmit = &s->port.state->xmit;
268
269	dev_dbg(&s->spi->dev, "%s\n", __func__);
270
271	rxchars = 0;
272	do {
273		spin_lock(&s->conf_lock);
274		conf = s->conf;
275		cconf = s->conf_commit;
276		s->conf_commit = 0;
277		rts = s->rts;
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
313		if (rxchars > 16) {
314			tty_flip_buffer_push(&s->port.state->port);
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
326	if (rxchars > 0)
327		tty_flip_buffer_push(&s->port.state->port);
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;
435
436	dev_dbg(&s->spi->dev, "%s\n", __func__);
437
438	cflag = termios->c_cflag;
439	param_new = 0;
440	param_mask = 0;
441
442	baud = tty_termios_baud_rate(termios);
443	param_new = s->conf & MAX3100_BAUD;
444	switch (baud) {
445	case 300:
446		if (s->crystal)
447			baud = s->baud;
448		else
449			param_new = 15;
450		break;
451	case 600:
452		param_new = 14 + s->crystal;
453		break;
454	case 1200:
455		param_new = 13 + s->crystal;
456		break;
457	case 2400:
458		param_new = 12 + s->crystal;
459		break;
460	case 4800:
461		param_new = 11 + s->crystal;
462		break;
463	case 9600:
464		param_new = 10 + s->crystal;
465		break;
466	case 19200:
467		param_new = 9 + s->crystal;
468		break;
469	case 38400:
470		param_new = 8 + s->crystal;
471		break;
472	case 57600:
473		param_new = 1 + s->crystal;
474		break;
475	case 115200:
476		param_new = 0 + s->crystal;
477		break;
478	case 230400:
479		if (s->crystal)
480			param_new = 0;
481		else
482			baud = s->baud;
483		break;
484	default:
485		baud = s->baud;
486	}
487	tty_termios_encode_baud_rate(termios, baud, baud);
488	s->baud = baud;
489	param_mask |= MAX3100_BAUD;
490
491	if ((cflag & CSIZE) == CS8) {
492		param_new &= ~MAX3100_L;
493		parity &= ~MAX3100_7BIT;
494	} else {
495		param_new |= MAX3100_L;
496		parity |= MAX3100_7BIT;
497		cflag = (cflag & ~CSIZE) | CS7;
498	}
499	param_mask |= MAX3100_L;
500
501	if (cflag & CSTOPB)
502		param_new |= MAX3100_ST;
503	else
504		param_new &= ~MAX3100_ST;
505	param_mask |= MAX3100_ST;
506
507	if (cflag & PARENB) {
508		param_new |= MAX3100_PE;
509		parity |= MAX3100_PARITY_ON;
510	} else {
511		param_new &= ~MAX3100_PE;
512		parity &= ~MAX3100_PARITY_ON;
513	}
514	param_mask |= MAX3100_PE;
515
516	if (cflag & PARODD)
517		parity |= MAX3100_PARITY_ODD;
518	else
519		parity &= ~MAX3100_PARITY_ODD;
520
521	/* mask termios capabilities we don't support */
522	cflag &= ~CMSPAR;
523	termios->c_cflag = cflag;
524
525	s->port.ignore_status_mask = 0;
526	if (termios->c_iflag & IGNPAR)
527		s->port.ignore_status_mask |=
528			MAX3100_STATUS_PE | MAX3100_STATUS_FE |
529			MAX3100_STATUS_OE;
530
531	/* we are sending char from a workqueue so enable */
532	s->port.state->port.low_latency = 1;
533
534	if (s->poll_time > 0)
535		del_timer_sync(&s->timer);
536
537	uart_update_timeout(port, termios->c_cflag, baud);
538
539	spin_lock(&s->conf_lock);
540	s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
541	s->conf_commit = 1;
542	s->parity = parity;
543	spin_unlock(&s->conf_lock);
544	max3100_dowork(s);
545
546	if (UART_ENABLE_MS(&s->port, termios->c_cflag))
547		max3100_enable_ms(&s->port);
548}
549
550static void max3100_shutdown(struct uart_port *port)
551{
552	struct max3100_port *s = container_of(port,
553					      struct max3100_port,
554					      port);
555
556	dev_dbg(&s->spi->dev, "%s\n", __func__);
557
558	if (s->suspending)
559		return;
560
561	s->force_end_work = 1;
562
563	if (s->poll_time > 0)
564		del_timer_sync(&s->timer);
565
566	if (s->workqueue) {
567		flush_workqueue(s->workqueue);
568		destroy_workqueue(s->workqueue);
569		s->workqueue = NULL;
570	}
571	if (s->irq)
572		free_irq(s->irq, s);
573
574	/* set shutdown mode to save power */
575	if (s->max3100_hw_suspend)
576		s->max3100_hw_suspend(1);
577	else  {
578		u16 tx, rx;
579
580		tx = MAX3100_WC | MAX3100_SHDN;
581		max3100_sr(s, tx, &rx);
582	}
583}
584
585static int max3100_startup(struct uart_port *port)
586{
587	struct max3100_port *s = container_of(port,
588					      struct max3100_port,
589					      port);
590	char b[12];
591
592	dev_dbg(&s->spi->dev, "%s\n", __func__);
593
594	s->conf = MAX3100_RM;
595	s->baud = s->crystal ? 230400 : 115200;
596	s->rx_enabled = 1;
597
598	if (s->suspending)
599		return 0;
600
601	s->force_end_work = 0;
602	s->parity = 0;
603	s->rts = 0;
604
605	sprintf(b, "max3100-%d", s->minor);
606	s->workqueue = create_freezable_workqueue(b);
607	if (!s->workqueue) {
608		dev_warn(&s->spi->dev, "cannot create workqueue\n");
609		return -EBUSY;
610	}
611	INIT_WORK(&s->work, max3100_work);
612
613	if (request_irq(s->irq, max3100_irq,
614			IRQF_TRIGGER_FALLING, "max3100", s) < 0) {
615		dev_warn(&s->spi->dev, "cannot allocate irq %d\n", s->irq);
616		s->irq = 0;
617		destroy_workqueue(s->workqueue);
618		s->workqueue = NULL;
619		return -EBUSY;
620	}
621
622	if (s->loopback) {
623		u16 tx, rx;
624		tx = 0x4001;
625		max3100_sr(s, tx, &rx);
626	}
627
628	if (s->max3100_hw_suspend)
629		s->max3100_hw_suspend(0);
630	s->conf_commit = 1;
631	max3100_dowork(s);
632	/* wait for clock to settle */
633	msleep(50);
634
635	max3100_enable_ms(&s->port);
636
637	return 0;
638}
639
640static const char *max3100_type(struct uart_port *port)
641{
642	struct max3100_port *s = container_of(port,
643					      struct max3100_port,
644					      port);
645
646	dev_dbg(&s->spi->dev, "%s\n", __func__);
647
648	return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL;
649}
650
651static void max3100_release_port(struct uart_port *port)
652{
653	struct max3100_port *s = container_of(port,
654					      struct max3100_port,
655					      port);
656
657	dev_dbg(&s->spi->dev, "%s\n", __func__);
658}
659
660static void max3100_config_port(struct uart_port *port, int flags)
661{
662	struct max3100_port *s = container_of(port,
663					      struct max3100_port,
664					      port);
665
666	dev_dbg(&s->spi->dev, "%s\n", __func__);
667
668	if (flags & UART_CONFIG_TYPE)
669		s->port.type = PORT_MAX3100;
670}
671
672static int max3100_verify_port(struct uart_port *port,
673			       struct serial_struct *ser)
674{
675	struct max3100_port *s = container_of(port,
676					      struct max3100_port,
677					      port);
678	int ret = -EINVAL;
679
680	dev_dbg(&s->spi->dev, "%s\n", __func__);
681
682	if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100)
683		ret = 0;
684	return ret;
685}
686
687static void max3100_stop_tx(struct uart_port *port)
688{
689	struct max3100_port *s = container_of(port,
690					      struct max3100_port,
691					      port);
692
693	dev_dbg(&s->spi->dev, "%s\n", __func__);
694}
695
696static int max3100_request_port(struct uart_port *port)
697{
698	struct max3100_port *s = container_of(port,
699					      struct max3100_port,
700					      port);
701
702	dev_dbg(&s->spi->dev, "%s\n", __func__);
703	return 0;
704}
705
706static void max3100_break_ctl(struct uart_port *port, int break_state)
707{
708	struct max3100_port *s = container_of(port,
709					      struct max3100_port,
710					      port);
711
712	dev_dbg(&s->spi->dev, "%s\n", __func__);
713}
714
715static struct uart_ops max3100_ops = {
716	.tx_empty	= max3100_tx_empty,
717	.set_mctrl	= max3100_set_mctrl,
718	.get_mctrl	= max3100_get_mctrl,
719	.stop_tx        = max3100_stop_tx,
720	.start_tx	= max3100_start_tx,
721	.stop_rx	= max3100_stop_rx,
722	.enable_ms      = max3100_enable_ms,
723	.break_ctl      = max3100_break_ctl,
724	.startup	= max3100_startup,
725	.shutdown	= max3100_shutdown,
726	.set_termios	= max3100_set_termios,
727	.type		= max3100_type,
728	.release_port   = max3100_release_port,
729	.request_port   = max3100_request_port,
730	.config_port	= max3100_config_port,
731	.verify_port	= max3100_verify_port,
732};
733
734static struct uart_driver max3100_uart_driver = {
735	.owner          = THIS_MODULE,
736	.driver_name    = "ttyMAX",
737	.dev_name       = "ttyMAX",
738	.major          = MAX3100_MAJOR,
739	.minor          = MAX3100_MINOR,
740	.nr             = MAX_MAX3100,
741};
742static int uart_driver_registered;
743
744static int max3100_probe(struct spi_device *spi)
745{
746	int i, retval;
747	struct plat_max3100 *pdata;
748	u16 tx, rx;
749
750	mutex_lock(&max3100s_lock);
751
752	if (!uart_driver_registered) {
753		uart_driver_registered = 1;
754		retval = uart_register_driver(&max3100_uart_driver);
755		if (retval) {
756			printk(KERN_ERR "Couldn't register max3100 uart driver\n");
757			mutex_unlock(&max3100s_lock);
758			return retval;
759		}
760	}
761
762	for (i = 0; i < MAX_MAX3100; i++)
763		if (!max3100s[i])
764			break;
765	if (i == MAX_MAX3100) {
766		dev_warn(&spi->dev, "too many MAX3100 chips\n");
767		mutex_unlock(&max3100s_lock);
768		return -ENOMEM;
769	}
770
771	max3100s[i] = kzalloc(sizeof(struct max3100_port), GFP_KERNEL);
772	if (!max3100s[i]) {
773		dev_warn(&spi->dev,
774			 "kmalloc for max3100 structure %d failed!\n", i);
775		mutex_unlock(&max3100s_lock);
776		return -ENOMEM;
777	}
778	max3100s[i]->spi = spi;
779	max3100s[i]->irq = spi->irq;
780	spin_lock_init(&max3100s[i]->conf_lock);
781	spi_set_drvdata(spi, max3100s[i]);
782	pdata = dev_get_platdata(&spi->dev);
783	max3100s[i]->crystal = pdata->crystal;
784	max3100s[i]->loopback = pdata->loopback;
785	max3100s[i]->poll_time = msecs_to_jiffies(pdata->poll_time);
786	if (pdata->poll_time > 0 && max3100s[i]->poll_time == 0)
787		max3100s[i]->poll_time = 1;
788	max3100s[i]->max3100_hw_suspend = pdata->max3100_hw_suspend;
789	max3100s[i]->minor = i;
790	init_timer(&max3100s[i]->timer);
791	max3100s[i]->timer.function = max3100_timeout;
792	max3100s[i]->timer.data = (unsigned long) max3100s[i];
793
794	dev_dbg(&spi->dev, "%s: adding port %d\n", __func__, i);
795	max3100s[i]->port.irq = max3100s[i]->irq;
796	max3100s[i]->port.uartclk = max3100s[i]->crystal ? 3686400 : 1843200;
797	max3100s[i]->port.fifosize = 16;
798	max3100s[i]->port.ops = &max3100_ops;
799	max3100s[i]->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
800	max3100s[i]->port.line = i;
801	max3100s[i]->port.type = PORT_MAX3100;
802	max3100s[i]->port.dev = &spi->dev;
803	retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port);
804	if (retval < 0)
805		dev_warn(&spi->dev,
806			 "uart_add_one_port failed for line %d with error %d\n",
807			 i, retval);
808
809	/* set shutdown mode to save power. Will be woken-up on open */
810	if (max3100s[i]->max3100_hw_suspend)
811		max3100s[i]->max3100_hw_suspend(1);
812	else {
813		tx = MAX3100_WC | MAX3100_SHDN;
814		max3100_sr(max3100s[i], tx, &rx);
815	}
816	mutex_unlock(&max3100s_lock);
817	return 0;
818}
819
820static int max3100_remove(struct spi_device *spi)
821{
822	struct max3100_port *s = spi_get_drvdata(spi);
823	int i;
824
825	mutex_lock(&max3100s_lock);
826
827	/* find out the index for the chip we are removing */
828	for (i = 0; i < MAX_MAX3100; i++)
829		if (max3100s[i] == s) {
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			break;
835		}
836
837	WARN_ON(i == MAX_MAX3100);
838
839	/* check if this is the last chip we have */
840	for (i = 0; i < MAX_MAX3100; i++)
841		if (max3100s[i]) {
842			mutex_unlock(&max3100s_lock);
843			return 0;
844		}
845	pr_debug("removing max3100 driver\n");
846	uart_unregister_driver(&max3100_uart_driver);
847
848	mutex_unlock(&max3100s_lock);
849	return 0;
850}
851
852#ifdef CONFIG_PM_SLEEP
853
854static int max3100_suspend(struct device *dev)
855{
856	struct max3100_port *s = dev_get_drvdata(dev);
857
858	dev_dbg(&s->spi->dev, "%s\n", __func__);
859
860	disable_irq(s->irq);
861
862	s->suspending = 1;
863	uart_suspend_port(&max3100_uart_driver, &s->port);
864
865	if (s->max3100_hw_suspend)
866		s->max3100_hw_suspend(1);
867	else {
868		/* no HW suspend, so do SW one */
869		u16 tx, rx;
870
871		tx = MAX3100_WC | MAX3100_SHDN;
872		max3100_sr(s, tx, &rx);
873	}
874	return 0;
875}
876
877static int max3100_resume(struct device *dev)
878{
879	struct max3100_port *s = dev_get_drvdata(dev);
880
881	dev_dbg(&s->spi->dev, "%s\n", __func__);
882
883	if (s->max3100_hw_suspend)
884		s->max3100_hw_suspend(0);
885	uart_resume_port(&max3100_uart_driver, &s->port);
886	s->suspending = 0;
887
888	enable_irq(s->irq);
889
890	s->conf_commit = 1;
891	if (s->workqueue)
892		max3100_dowork(s);
893
894	return 0;
895}
896
897static SIMPLE_DEV_PM_OPS(max3100_pm_ops, max3100_suspend, max3100_resume);
898#define MAX3100_PM_OPS (&max3100_pm_ops)
899
900#else
901#define MAX3100_PM_OPS NULL
902#endif
903
904static struct spi_driver max3100_driver = {
905	.driver = {
906		.name		= "max3100",
907		.owner		= THIS_MODULE,
908		.pm		= MAX3100_PM_OPS,
909	},
910	.probe		= max3100_probe,
911	.remove		= max3100_remove,
912};
913
914module_spi_driver(max3100_driver);
915
916MODULE_DESCRIPTION("MAX3100 driver");
917MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
918MODULE_LICENSE("GPL");
919MODULE_ALIAS("spi:max3100");
920