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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* linux/drivers/i2c/busses/i2c-s3c2410.c
2 *
3 * Copyright (C) 2004,2005 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * S3C2410 I2C Controller
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21*/
22
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/kernel.h>
24#include <linux/module.h>
25
26#include <linux/i2c.h>
27#include <linux/i2c-id.h>
28#include <linux/init.h>
29#include <linux/time.h>
30#include <linux/interrupt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/delay.h>
32#include <linux/errno.h>
33#include <linux/err.h>
Russell Kingd052d1b2005-10-29 19:07:23 +010034#include <linux/platform_device.h>
Russell Kingf8ce2542006-01-07 16:15:52 +000035#include <linux/clk.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37#include <asm/hardware.h>
38#include <asm/irq.h>
39#include <asm/io.h>
40
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <asm/arch/regs-gpio.h>
Ben Dooksb5d0b4b2007-08-14 18:37:15 +020042#include <asm/plat-s3c/regs-iic.h>
43#include <asm/plat-s3c/iic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
45/* i2c controller state */
46
47enum s3c24xx_i2c_state {
48 STATE_IDLE,
49 STATE_START,
50 STATE_READ,
51 STATE_WRITE,
52 STATE_STOP
53};
54
55struct s3c24xx_i2c {
56 spinlock_t lock;
57 wait_queue_head_t wait;
58
59 struct i2c_msg *msg;
60 unsigned int msg_num;
61 unsigned int msg_idx;
62 unsigned int msg_ptr;
63
Ben Dookse00a8cd2007-05-01 23:26:35 +020064 unsigned int tx_setup;
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 enum s3c24xx_i2c_state state;
67
68 void __iomem *regs;
69 struct clk *clk;
70 struct device *dev;
71 struct resource *irq;
72 struct resource *ioarea;
73 struct i2c_adapter adap;
74};
75
76/* default platform data to use if not supplied in the platform_device
77*/
78
79static struct s3c2410_platform_i2c s3c24xx_i2c_default_platform = {
80 .flags = 0,
81 .slave_addr = 0x10,
82 .bus_freq = 100*1000,
83 .max_freq = 400*1000,
84 .sda_delay = S3C2410_IICLC_SDA_DELAY5 | S3C2410_IICLC_FILTER_ON,
85};
86
87/* s3c24xx_i2c_is2440()
88 *
89 * return true is this is an s3c2440
90*/
91
92static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
93{
94 struct platform_device *pdev = to_platform_device(i2c->dev);
95
96 return !strcmp(pdev->name, "s3c2440-i2c");
97}
98
99
100/* s3c24xx_i2c_get_platformdata
101 *
102 * get the platform data associated with the given device, or return
103 * the default if there is none
104*/
105
106static inline struct s3c2410_platform_i2c *s3c24xx_i2c_get_platformdata(struct device *dev)
107{
108 if (dev->platform_data != NULL)
109 return (struct s3c2410_platform_i2c *)dev->platform_data;
110
111 return &s3c24xx_i2c_default_platform;
112}
113
114/* s3c24xx_i2c_master_complete
115 *
116 * complete the message and wake up the caller, using the given return code,
117 * or zero to mean ok.
118*/
119
120static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret)
121{
122 dev_dbg(i2c->dev, "master_complete %d\n", ret);
123
124 i2c->msg_ptr = 0;
125 i2c->msg = NULL;
126 i2c->msg_idx ++;
127 i2c->msg_num = 0;
128 if (ret)
129 i2c->msg_idx = ret;
130
131 wake_up(&i2c->wait);
132}
133
134static inline void s3c24xx_i2c_disable_ack(struct s3c24xx_i2c *i2c)
135{
136 unsigned long tmp;
137
138 tmp = readl(i2c->regs + S3C2410_IICCON);
139 writel(tmp & ~S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON);
140
141}
142
143static inline void s3c24xx_i2c_enable_ack(struct s3c24xx_i2c *i2c)
144{
145 unsigned long tmp;
146
147 tmp = readl(i2c->regs + S3C2410_IICCON);
148 writel(tmp | S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON);
149
150}
151
152/* irq enable/disable functions */
153
154static inline void s3c24xx_i2c_disable_irq(struct s3c24xx_i2c *i2c)
155{
156 unsigned long tmp;
157
158 tmp = readl(i2c->regs + S3C2410_IICCON);
159 writel(tmp & ~S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
160}
161
162static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c)
163{
164 unsigned long tmp;
165
166 tmp = readl(i2c->regs + S3C2410_IICCON);
167 writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
168}
169
170
171/* s3c24xx_i2c_message_start
172 *
173 * put the start of a message onto the bus
174*/
175
176static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c,
177 struct i2c_msg *msg)
178{
179 unsigned int addr = (msg->addr & 0x7f) << 1;
180 unsigned long stat;
181 unsigned long iiccon;
182
183 stat = 0;
184 stat |= S3C2410_IICSTAT_TXRXEN;
185
186 if (msg->flags & I2C_M_RD) {
187 stat |= S3C2410_IICSTAT_MASTER_RX;
188 addr |= 1;
189 } else
190 stat |= S3C2410_IICSTAT_MASTER_TX;
191
192 if (msg->flags & I2C_M_REV_DIR_ADDR)
193 addr ^= 1;
194
195 // todo - check for wether ack wanted or not
196 s3c24xx_i2c_enable_ack(i2c);
197
198 iiccon = readl(i2c->regs + S3C2410_IICCON);
199 writel(stat, i2c->regs + S3C2410_IICSTAT);
200
201 dev_dbg(i2c->dev, "START: %08lx to IICSTAT, %02x to DS\n", stat, addr);
202 writeb(addr, i2c->regs + S3C2410_IICDS);
203
Ben Dookse00a8cd2007-05-01 23:26:35 +0200204 /* delay here to ensure the data byte has gotten onto the bus
205 * before the transaction is started */
206
207 ndelay(i2c->tx_setup);
208
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 dev_dbg(i2c->dev, "iiccon, %08lx\n", iiccon);
210 writel(iiccon, i2c->regs + S3C2410_IICCON);
211
212 stat |= S3C2410_IICSTAT_START;
213 writel(stat, i2c->regs + S3C2410_IICSTAT);
214}
215
216static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret)
217{
218 unsigned long iicstat = readl(i2c->regs + S3C2410_IICSTAT);
219
220 dev_dbg(i2c->dev, "STOP\n");
221
222 /* stop the transfer */
223 iicstat &= ~ S3C2410_IICSTAT_START;
224 writel(iicstat, i2c->regs + S3C2410_IICSTAT);
225
226 i2c->state = STATE_STOP;
227
228 s3c24xx_i2c_master_complete(i2c, ret);
229 s3c24xx_i2c_disable_irq(i2c);
230}
231
232/* helper functions to determine the current state in the set of
233 * messages we are sending */
234
235/* is_lastmsg()
236 *
237 * returns TRUE if the current message is the last in the set
238*/
239
240static inline int is_lastmsg(struct s3c24xx_i2c *i2c)
241{
242 return i2c->msg_idx >= (i2c->msg_num - 1);
243}
244
245/* is_msglast
246 *
247 * returns TRUE if we this is the last byte in the current message
248*/
249
250static inline int is_msglast(struct s3c24xx_i2c *i2c)
251{
252 return i2c->msg_ptr == i2c->msg->len-1;
253}
254
255/* is_msgend
256 *
257 * returns TRUE if we reached the end of the current message
258*/
259
260static inline int is_msgend(struct s3c24xx_i2c *i2c)
261{
262 return i2c->msg_ptr >= i2c->msg->len;
263}
264
265/* i2s_s3c_irq_nextbyte
266 *
267 * process an interrupt and work out what to do
268 */
269
270static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat)
271{
272 unsigned long tmp;
273 unsigned char byte;
274 int ret = 0;
275
276 switch (i2c->state) {
277
278 case STATE_IDLE:
Harvey Harrison08882d22008-04-22 22:16:47 +0200279 dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 goto out;
281 break;
282
283 case STATE_STOP:
Harvey Harrison08882d22008-04-22 22:16:47 +0200284 dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 s3c24xx_i2c_disable_irq(i2c);
286 goto out_ack;
287
288 case STATE_START:
289 /* last thing we did was send a start condition on the
290 * bus, or started a new i2c message
291 */
292
293 if (iicstat & S3C2410_IICSTAT_LASTBIT &&
294 !(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
295 /* ack was not received... */
296
297 dev_dbg(i2c->dev, "ack was not received\n");
298 s3c24xx_i2c_stop(i2c, -EREMOTEIO);
299 goto out_ack;
300 }
301
302 if (i2c->msg->flags & I2C_M_RD)
303 i2c->state = STATE_READ;
304 else
305 i2c->state = STATE_WRITE;
306
307 /* terminate the transfer if there is nothing to do
308 * (used by the i2c probe to find devices */
309
310 if (is_lastmsg(i2c) && i2c->msg->len == 0) {
311 s3c24xx_i2c_stop(i2c, 0);
312 goto out_ack;
313 }
314
315 if (i2c->state == STATE_READ)
316 goto prepare_read;
317
318 /* fall through to the write state, as we will need to
319 * send a byte as well */
320
321 case STATE_WRITE:
322 /* we are writing data to the device... check for the
323 * end of the message, and if so, work out what to do
324 */
325
Ben Dooks27097812008-07-01 11:59:41 +0100326 if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
327 if (iicstat & S3C2410_IICSTAT_LASTBIT) {
328 dev_dbg(i2c->dev, "WRITE: No Ack\n");
329
330 s3c24xx_i2c_stop(i2c, -ECONNREFUSED);
331 goto out_ack;
332 }
333 }
334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 retry_write:
Ben Dooks27097812008-07-01 11:59:41 +0100336
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 if (!is_msgend(i2c)) {
338 byte = i2c->msg->buf[i2c->msg_ptr++];
339 writeb(byte, i2c->regs + S3C2410_IICDS);
Ben Dookse00a8cd2007-05-01 23:26:35 +0200340
341 /* delay after writing the byte to allow the
342 * data setup time on the bus, as writing the
343 * data to the register causes the first bit
344 * to appear on SDA, and SCL will change as
345 * soon as the interrupt is acknowledged */
346
347 ndelay(i2c->tx_setup);
348
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 } else if (!is_lastmsg(i2c)) {
350 /* we need to go to the next i2c message */
351
352 dev_dbg(i2c->dev, "WRITE: Next Message\n");
353
354 i2c->msg_ptr = 0;
355 i2c->msg_idx ++;
356 i2c->msg++;
357
358 /* check to see if we need to do another message */
359 if (i2c->msg->flags & I2C_M_NOSTART) {
360
361 if (i2c->msg->flags & I2C_M_RD) {
362 /* cannot do this, the controller
363 * forces us to send a new START
364 * when we change direction */
365
366 s3c24xx_i2c_stop(i2c, -EINVAL);
367 }
368
369 goto retry_write;
370 } else {
371
372 /* send the new start */
373 s3c24xx_i2c_message_start(i2c, i2c->msg);
374 i2c->state = STATE_START;
375 }
376
377 } else {
378 /* send stop */
379
380 s3c24xx_i2c_stop(i2c, 0);
381 }
382 break;
383
384 case STATE_READ:
385 /* we have a byte of data in the data register, do
386 * something with it, and then work out wether we are
387 * going to do any more read/write
388 */
389
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 byte = readb(i2c->regs + S3C2410_IICDS);
391 i2c->msg->buf[i2c->msg_ptr++] = byte;
392
393 prepare_read:
394 if (is_msglast(i2c)) {
395 /* last byte of buffer */
396
397 if (is_lastmsg(i2c))
398 s3c24xx_i2c_disable_ack(i2c);
399
400 } else if (is_msgend(i2c)) {
401 /* ok, we've read the entire buffer, see if there
402 * is anything else we need to do */
403
404 if (is_lastmsg(i2c)) {
405 /* last message, send stop and complete */
406 dev_dbg(i2c->dev, "READ: Send Stop\n");
407
408 s3c24xx_i2c_stop(i2c, 0);
409 } else {
410 /* go to the next transfer */
411 dev_dbg(i2c->dev, "READ: Next Transfer\n");
412
413 i2c->msg_ptr = 0;
414 i2c->msg_idx++;
415 i2c->msg++;
416 }
417 }
418
419 break;
420 }
421
422 /* acknowlegde the IRQ and get back on with the work */
423
424 out_ack:
425 tmp = readl(i2c->regs + S3C2410_IICCON);
426 tmp &= ~S3C2410_IICCON_IRQPEND;
427 writel(tmp, i2c->regs + S3C2410_IICCON);
428 out:
429 return ret;
430}
431
432/* s3c24xx_i2c_irq
433 *
434 * top level IRQ servicing routine
435*/
436
David Howells7d12e782006-10-05 14:55:46 +0100437static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438{
439 struct s3c24xx_i2c *i2c = dev_id;
440 unsigned long status;
441 unsigned long tmp;
442
443 status = readl(i2c->regs + S3C2410_IICSTAT);
444
445 if (status & S3C2410_IICSTAT_ARBITR) {
446 // deal with arbitration loss
447 dev_err(i2c->dev, "deal with arbitration loss\n");
448 }
449
450 if (i2c->state == STATE_IDLE) {
451 dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n");
452
453 tmp = readl(i2c->regs + S3C2410_IICCON);
454 tmp &= ~S3C2410_IICCON_IRQPEND;
455 writel(tmp, i2c->regs + S3C2410_IICCON);
456 goto out;
457 }
458
459 /* pretty much this leaves us with the fact that we've
460 * transmitted or received whatever byte we last sent */
461
462 i2s_s3c_irq_nextbyte(i2c, status);
463
464 out:
465 return IRQ_HANDLED;
466}
467
468
469/* s3c24xx_i2c_set_master
470 *
471 * get the i2c bus for a master transaction
472*/
473
474static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c)
475{
476 unsigned long iicstat;
477 int timeout = 400;
478
479 while (timeout-- > 0) {
480 iicstat = readl(i2c->regs + S3C2410_IICSTAT);
481
482 if (!(iicstat & S3C2410_IICSTAT_BUSBUSY))
483 return 0;
484
485 msleep(1);
486 }
487
488 dev_dbg(i2c->dev, "timeout: GPEDAT is %08x\n",
489 __raw_readl(S3C2410_GPEDAT));
490
491 return -ETIMEDOUT;
492}
493
494/* s3c24xx_i2c_doxfer
495 *
496 * this starts an i2c transfer
497*/
498
499static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int num)
500{
501 unsigned long timeout;
502 int ret;
503
504 ret = s3c24xx_i2c_set_master(i2c);
505 if (ret != 0) {
506 dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
507 ret = -EAGAIN;
508 goto out;
509 }
510
511 spin_lock_irq(&i2c->lock);
512
513 i2c->msg = msgs;
514 i2c->msg_num = num;
515 i2c->msg_ptr = 0;
516 i2c->msg_idx = 0;
517 i2c->state = STATE_START;
518
519 s3c24xx_i2c_enable_irq(i2c);
520 s3c24xx_i2c_message_start(i2c, msgs);
521 spin_unlock_irq(&i2c->lock);
522
523 timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
524
525 ret = i2c->msg_idx;
526
527 /* having these next two as dev_err() makes life very
528 * noisy when doing an i2cdetect */
529
530 if (timeout == 0)
531 dev_dbg(i2c->dev, "timeout\n");
532 else if (ret != num)
533 dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
534
535 /* ensure the stop has been through the bus */
536
537 msleep(1);
538
539 out:
540 return ret;
541}
542
543/* s3c24xx_i2c_xfer
544 *
545 * first port of call from the i2c bus code when an message needs
Steven Cole44bbe872005-05-03 18:21:25 -0600546 * transferring across the i2c bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547*/
548
549static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
550 struct i2c_msg *msgs, int num)
551{
552 struct s3c24xx_i2c *i2c = (struct s3c24xx_i2c *)adap->algo_data;
553 int retry;
554 int ret;
555
556 for (retry = 0; retry < adap->retries; retry++) {
557
558 ret = s3c24xx_i2c_doxfer(i2c, msgs, num);
559
560 if (ret != -EAGAIN)
561 return ret;
562
563 dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
564
565 udelay(100);
566 }
567
568 return -EREMOTEIO;
569}
570
571/* declare our i2c functionality */
572static u32 s3c24xx_i2c_func(struct i2c_adapter *adap)
573{
574 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
575}
576
577/* i2c bus registration info */
578
Jean Delvare8f9082c2006-09-03 22:39:46 +0200579static const struct i2c_algorithm s3c24xx_i2c_algorithm = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 .master_xfer = s3c24xx_i2c_xfer,
581 .functionality = s3c24xx_i2c_func,
582};
583
584static struct s3c24xx_i2c s3c24xx_i2c = {
Ben Dookse00a8cd2007-05-01 23:26:35 +0200585 .lock = __SPIN_LOCK_UNLOCKED(s3c24xx_i2c.lock),
586 .wait = __WAIT_QUEUE_HEAD_INITIALIZER(s3c24xx_i2c.wait),
587 .tx_setup = 50,
588 .adap = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 .name = "s3c2410-i2c",
590 .owner = THIS_MODULE,
591 .algo = &s3c24xx_i2c_algorithm,
592 .retries = 2,
593 .class = I2C_CLASS_HWMON,
594 },
595};
596
597/* s3c24xx_i2c_calcdivisor
598 *
599 * return the divisor settings for a given frequency
600*/
601
602static int s3c24xx_i2c_calcdivisor(unsigned long clkin, unsigned int wanted,
603 unsigned int *div1, unsigned int *divs)
604{
605 unsigned int calc_divs = clkin / wanted;
606 unsigned int calc_div1;
607
608 if (calc_divs > (16*16))
609 calc_div1 = 512;
610 else
611 calc_div1 = 16;
612
613 calc_divs += calc_div1-1;
614 calc_divs /= calc_div1;
615
616 if (calc_divs == 0)
617 calc_divs = 1;
618 if (calc_divs > 17)
619 calc_divs = 17;
620
621 *divs = calc_divs;
622 *div1 = calc_div1;
623
624 return clkin / (calc_divs * calc_div1);
625}
626
627/* freq_acceptable
628 *
629 * test wether a frequency is within the acceptable range of error
630*/
631
632static inline int freq_acceptable(unsigned int freq, unsigned int wanted)
633{
634 int diff = freq - wanted;
635
636 return (diff >= -2 && diff <= 2);
637}
638
639/* s3c24xx_i2c_getdivisor
640 *
641 * work out a divisor for the user requested frequency setting,
642 * either by the requested frequency, or scanning the acceptable
643 * range of frequencies until something is found
644*/
645
646static int s3c24xx_i2c_getdivisor(struct s3c24xx_i2c *i2c,
647 struct s3c2410_platform_i2c *pdata,
648 unsigned long *iicon,
649 unsigned int *got)
650{
651 unsigned long clkin = clk_get_rate(i2c->clk);
652
653 unsigned int divs, div1;
654 int freq;
655 int start, end;
656
657 clkin /= 1000; /* clkin now in KHz */
658
659 dev_dbg(i2c->dev, "pdata %p, freq %lu %lu..%lu\n",
660 pdata, pdata->bus_freq, pdata->min_freq, pdata->max_freq);
661
662 if (pdata->bus_freq != 0) {
663 freq = s3c24xx_i2c_calcdivisor(clkin, pdata->bus_freq/1000,
664 &div1, &divs);
665 if (freq_acceptable(freq, pdata->bus_freq/1000))
666 goto found;
667 }
668
669 /* ok, we may have to search for something suitable... */
670
671 start = (pdata->max_freq == 0) ? pdata->bus_freq : pdata->max_freq;
672 end = pdata->min_freq;
673
674 start /= 1000;
675 end /= 1000;
676
677 /* search loop... */
678
679 for (; start > end; start--) {
680 freq = s3c24xx_i2c_calcdivisor(clkin, start, &div1, &divs);
681 if (freq_acceptable(freq, start))
682 goto found;
683 }
684
685 /* cannot find frequency spec */
686
687 return -EINVAL;
688
689 found:
690 *got = freq;
691 *iicon |= (divs-1);
692 *iicon |= (div1 == 512) ? S3C2410_IICCON_TXDIV_512 : 0;
693 return 0;
694}
695
696/* s3c24xx_i2c_init
697 *
698 * initialise the controller, set the IO lines and frequency
699*/
700
701static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
702{
703 unsigned long iicon = S3C2410_IICCON_IRQEN | S3C2410_IICCON_ACKEN;
704 struct s3c2410_platform_i2c *pdata;
705 unsigned int freq;
706
707 /* get the plafrom data */
708
709 pdata = s3c24xx_i2c_get_platformdata(i2c->adap.dev.parent);
710
711 /* inititalise the gpio */
712
713 s3c2410_gpio_cfgpin(S3C2410_GPE15, S3C2410_GPE15_IICSDA);
714 s3c2410_gpio_cfgpin(S3C2410_GPE14, S3C2410_GPE14_IICSCL);
715
716 /* write slave address */
717
718 writeb(pdata->slave_addr, i2c->regs + S3C2410_IICADD);
719
720 dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr);
721
722 /* we need to work out the divisors for the clock... */
723
724 if (s3c24xx_i2c_getdivisor(i2c, pdata, &iicon, &freq) != 0) {
725 dev_err(i2c->dev, "cannot meet bus frequency required\n");
726 return -EINVAL;
727 }
728
729 /* todo - check that the i2c lines aren't being dragged anywhere */
730
731 dev_info(i2c->dev, "bus frequency set to %d KHz\n", freq);
732 dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02lx\n", iicon);
733
734 writel(iicon, i2c->regs + S3C2410_IICCON);
735
736 /* check for s3c2440 i2c controller */
737
738 if (s3c24xx_i2c_is2440(i2c)) {
739 dev_dbg(i2c->dev, "S3C2440_IICLC=%08x\n", pdata->sda_delay);
740
741 writel(pdata->sda_delay, i2c->regs + S3C2440_IICLC);
742 }
743
744 return 0;
745}
746
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747/* s3c24xx_i2c_probe
748 *
749 * called by the bus driver when a suitable device is found
750*/
751
Russell King3ae5eae2005-11-09 22:32:44 +0000752static int s3c24xx_i2c_probe(struct platform_device *pdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 struct s3c24xx_i2c *i2c = &s3c24xx_i2c;
755 struct resource *res;
756 int ret;
757
758 /* find the clock and enable it */
759
Russell King3ae5eae2005-11-09 22:32:44 +0000760 i2c->dev = &pdev->dev;
761 i2c->clk = clk_get(&pdev->dev, "i2c");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 if (IS_ERR(i2c->clk)) {
Russell King3ae5eae2005-11-09 22:32:44 +0000763 dev_err(&pdev->dev, "cannot get clock\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 ret = -ENOENT;
Ben Dooks5b687902007-05-01 23:26:35 +0200765 goto err_noclk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 }
767
Russell King3ae5eae2005-11-09 22:32:44 +0000768 dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 clk_enable(i2c->clk);
771
772 /* map the registers */
773
774 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
775 if (res == NULL) {
Russell King3ae5eae2005-11-09 22:32:44 +0000776 dev_err(&pdev->dev, "cannot find IO resource\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 ret = -ENOENT;
Ben Dooks5b687902007-05-01 23:26:35 +0200778 goto err_clk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 }
780
781 i2c->ioarea = request_mem_region(res->start, (res->end-res->start)+1,
782 pdev->name);
783
784 if (i2c->ioarea == NULL) {
Russell King3ae5eae2005-11-09 22:32:44 +0000785 dev_err(&pdev->dev, "cannot request IO\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 ret = -ENXIO;
Ben Dooks5b687902007-05-01 23:26:35 +0200787 goto err_clk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 }
789
790 i2c->regs = ioremap(res->start, (res->end-res->start)+1);
791
792 if (i2c->regs == NULL) {
Russell King3ae5eae2005-11-09 22:32:44 +0000793 dev_err(&pdev->dev, "cannot map IO\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 ret = -ENXIO;
Ben Dooks5b687902007-05-01 23:26:35 +0200795 goto err_ioarea;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 }
797
Russell King3ae5eae2005-11-09 22:32:44 +0000798 dev_dbg(&pdev->dev, "registers %p (%p, %p)\n", i2c->regs, i2c->ioarea, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799
800 /* setup info block for the i2c core */
801
802 i2c->adap.algo_data = i2c;
Russell King3ae5eae2005-11-09 22:32:44 +0000803 i2c->adap.dev.parent = &pdev->dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804
805 /* initialise the i2c controller */
806
807 ret = s3c24xx_i2c_init(i2c);
808 if (ret != 0)
Ben Dooks5b687902007-05-01 23:26:35 +0200809 goto err_iomap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810
811 /* find the IRQ for this unit (note, this relies on the init call to
812 * ensure no current IRQs pending
813 */
814
815 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
816 if (res == NULL) {
Russell King3ae5eae2005-11-09 22:32:44 +0000817 dev_err(&pdev->dev, "cannot find IRQ\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 ret = -ENOENT;
Ben Dooks5b687902007-05-01 23:26:35 +0200819 goto err_iomap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 }
821
Thomas Gleixnerdace1452006-07-01 19:29:38 -0700822 ret = request_irq(res->start, s3c24xx_i2c_irq, IRQF_DISABLED,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 pdev->name, i2c);
824
825 if (ret != 0) {
Russell King3ae5eae2005-11-09 22:32:44 +0000826 dev_err(&pdev->dev, "cannot claim IRQ\n");
Ben Dooks5b687902007-05-01 23:26:35 +0200827 goto err_iomap;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 }
829
830 i2c->irq = res;
831
Arnaud Patarda1ba1582007-05-22 19:49:16 +0200832 dev_dbg(&pdev->dev, "irq resource %p (%lu)\n", res,
833 (unsigned long)res->start);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834
835 ret = i2c_add_adapter(&i2c->adap);
836 if (ret < 0) {
Russell King3ae5eae2005-11-09 22:32:44 +0000837 dev_err(&pdev->dev, "failed to add bus to i2c core\n");
Ben Dooks5b687902007-05-01 23:26:35 +0200838 goto err_irq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 }
840
Russell King3ae5eae2005-11-09 22:32:44 +0000841 platform_set_drvdata(pdev, i2c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842
Russell King3ae5eae2005-11-09 22:32:44 +0000843 dev_info(&pdev->dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id);
Ben Dooks5b687902007-05-01 23:26:35 +0200844 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845
Ben Dooks5b687902007-05-01 23:26:35 +0200846 err_irq:
847 free_irq(i2c->irq->start, i2c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848
Ben Dooks5b687902007-05-01 23:26:35 +0200849 err_iomap:
850 iounmap(i2c->regs);
851
852 err_ioarea:
853 release_resource(i2c->ioarea);
854 kfree(i2c->ioarea);
855
856 err_clk:
857 clk_disable(i2c->clk);
858 clk_put(i2c->clk);
859
860 err_noclk:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 return ret;
862}
863
864/* s3c24xx_i2c_remove
865 *
866 * called when device is removed from the bus
867*/
868
Russell King3ae5eae2005-11-09 22:32:44 +0000869static int s3c24xx_i2c_remove(struct platform_device *pdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870{
Russell King3ae5eae2005-11-09 22:32:44 +0000871 struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
Ben Dooks5b687902007-05-01 23:26:35 +0200872
873 i2c_del_adapter(&i2c->adap);
874 free_irq(i2c->irq->start, i2c);
875
876 clk_disable(i2c->clk);
877 clk_put(i2c->clk);
878
879 iounmap(i2c->regs);
880
881 release_resource(i2c->ioarea);
882 kfree(i2c->ioarea);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
884 return 0;
885}
886
887#ifdef CONFIG_PM
Russell King3ae5eae2005-11-09 22:32:44 +0000888static int s3c24xx_i2c_resume(struct platform_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889{
Russell King3ae5eae2005-11-09 22:32:44 +0000890 struct s3c24xx_i2c *i2c = platform_get_drvdata(dev);
Russell King9480e302005-10-28 09:52:56 -0700891
892 if (i2c != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 s3c24xx_i2c_init(i2c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894
895 return 0;
896}
897
898#else
899#define s3c24xx_i2c_resume NULL
900#endif
901
902/* device driver for platform bus bits */
903
Russell King3ae5eae2005-11-09 22:32:44 +0000904static struct platform_driver s3c2410_i2c_driver = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 .probe = s3c24xx_i2c_probe,
906 .remove = s3c24xx_i2c_remove,
907 .resume = s3c24xx_i2c_resume,
Russell King3ae5eae2005-11-09 22:32:44 +0000908 .driver = {
909 .owner = THIS_MODULE,
910 .name = "s3c2410-i2c",
911 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912};
913
Russell King3ae5eae2005-11-09 22:32:44 +0000914static struct platform_driver s3c2440_i2c_driver = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 .probe = s3c24xx_i2c_probe,
916 .remove = s3c24xx_i2c_remove,
917 .resume = s3c24xx_i2c_resume,
Russell King3ae5eae2005-11-09 22:32:44 +0000918 .driver = {
919 .owner = THIS_MODULE,
920 .name = "s3c2440-i2c",
921 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922};
923
924static int __init i2c_adap_s3c_init(void)
925{
926 int ret;
927
Russell King3ae5eae2005-11-09 22:32:44 +0000928 ret = platform_driver_register(&s3c2410_i2c_driver);
Russell Kinge32e28e2005-10-30 16:32:27 +0000929 if (ret == 0) {
Russell King3ae5eae2005-11-09 22:32:44 +0000930 ret = platform_driver_register(&s3c2440_i2c_driver);
Russell Kinge32e28e2005-10-30 16:32:27 +0000931 if (ret)
Russell King3ae5eae2005-11-09 22:32:44 +0000932 platform_driver_unregister(&s3c2410_i2c_driver);
Russell Kinge32e28e2005-10-30 16:32:27 +0000933 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934
935 return ret;
936}
937
938static void __exit i2c_adap_s3c_exit(void)
939{
Russell King3ae5eae2005-11-09 22:32:44 +0000940 platform_driver_unregister(&s3c2410_i2c_driver);
941 platform_driver_unregister(&s3c2440_i2c_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942}
943
944module_init(i2c_adap_s3c_init);
945module_exit(i2c_adap_s3c_exit);
946
947MODULE_DESCRIPTION("S3C24XX I2C Bus driver");
948MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
949MODULE_LICENSE("GPL");
Kay Sieversadd8eda2008-04-22 22:16:49 +0200950MODULE_ALIAS("platform:s3c2410-i2c");