tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * SuperH Mobile I2C Controller
3 *
4 * Copyright (C) 2008 Magnus Damm
5 *
6 * Portions of the code based on out-of-tree driver i2c-sh7343.c
7 * Copyright (c) 2006 Carlos Munoz <carlos@kenati.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License
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
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/delay.h>
27#include <linux/platform_device.h>
28#include <linux/interrupt.h>
29#include <linux/i2c.h>
30#include <linux/of_i2c.h>
31#include <linux/err.h>
32#include <linux/pm_runtime.h>
33#include <linux/clk.h>
34#include <linux/io.h>
35#include <linux/slab.h>
36#include <linux/i2c/i2c-sh_mobile.h>
37
38/* Transmit operation: */
39/* */
40/* 0 byte transmit */
41/* BUS: S A8 ACK P(*) */
42/* IRQ: DTE WAIT */
43/* ICIC: */
44/* ICCR: 0x94 0x90 */
45/* ICDR: A8 */
46/* */
47/* 1 byte transmit */
48/* BUS: S A8 ACK D8(1) ACK P(*) */
49/* IRQ: DTE WAIT WAIT */
50/* ICIC: -DTE */
51/* ICCR: 0x94 0x90 */
52/* ICDR: A8 D8(1) */
53/* */
54/* 2 byte transmit */
55/* BUS: S A8 ACK D8(1) ACK D8(2) ACK P(*) */
56/* IRQ: DTE WAIT WAIT WAIT */
57/* ICIC: -DTE */
58/* ICCR: 0x94 0x90 */
59/* ICDR: A8 D8(1) D8(2) */
60/* */
61/* 3 bytes or more, +---------+ gets repeated */
62/* */
63/* */
64/* Receive operation: */
65/* */
66/* 0 byte receive - not supported since slave may hold SDA low */
67/* */
68/* 1 byte receive [TX] | [RX] */
69/* BUS: S A8 ACK | D8(1) ACK P(*) */
70/* IRQ: DTE WAIT | WAIT DTE */
71/* ICIC: -DTE | +DTE */
72/* ICCR: 0x94 0x81 | 0xc0 */
73/* ICDR: A8 | D8(1) */
74/* */
75/* 2 byte receive [TX]| [RX] */
76/* BUS: S A8 ACK | D8(1) ACK D8(2) ACK P(*) */
77/* IRQ: DTE WAIT | WAIT WAIT DTE */
78/* ICIC: -DTE | +DTE */
79/* ICCR: 0x94 0x81 | 0xc0 */
80/* ICDR: A8 | D8(1) D8(2) */
81/* */
82/* 3 byte receive [TX] | [RX] (*) */
83/* BUS: S A8 ACK | D8(1) ACK D8(2) ACK D8(3) ACK P */
84/* IRQ: DTE WAIT | WAIT WAIT WAIT DTE */
85/* ICIC: -DTE | +DTE */
86/* ICCR: 0x94 0x81 | 0xc0 */
87/* ICDR: A8 | D8(1) D8(2) D8(3) */
88/* */
89/* 4 bytes or more, this part is repeated +---------+ */
90/* */
91/* */
92/* Interrupt order and BUSY flag */
93/* ___ _ */
94/* SDA ___\___XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXAAAAAAAAA___/ */
95/* SCL \_/1\_/2\_/3\_/4\_/5\_/6\_/7\_/8\___/9\_____/ */
96/* */
97/* S D7 D6 D5 D4 D3 D2 D1 D0 P(*) */
98/* ___ */
99/* WAIT IRQ ________________________________/ \___________ */
100/* TACK IRQ ____________________________________/ \_______ */
101/* DTE IRQ __________________________________________/ \_ */
102/* AL IRQ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
103/* _______________________________________________ */
104/* BUSY __/ \_ */
105/* */
106/* (*) The STOP condition is only sent by the master at the end of the last */
107/* I2C message or if the I2C_M_STOP flag is set. Similarly, the BUSY bit is */
108/* only cleared after the STOP condition, so, between messages we have to */
109/* poll for the DTE bit. */
110/* */
111
112enum sh_mobile_i2c_op {
113 OP_START = 0,
114 OP_TX_FIRST,
115 OP_TX,
116 OP_TX_STOP,
117 OP_TX_TO_RX,
118 OP_RX,
119 OP_RX_STOP,
120 OP_RX_STOP_DATA,
121};
122
123struct sh_mobile_i2c_data {
124 struct device *dev;
125 void __iomem *reg;
126 struct i2c_adapter adap;
127 unsigned long bus_speed;
128 unsigned int clks_per_count;
129 struct clk *clk;
130 u_int8_t icic;
131 u_int8_t flags;
132 u_int16_t iccl;
133 u_int16_t icch;
134
135 spinlock_t lock;
136 wait_queue_head_t wait;
137 struct i2c_msg *msg;
138 int pos;
139 int sr;
140 bool send_stop;
141};
142
143#define IIC_FLAG_HAS_ICIC67 (1 << 0)
144
145#define STANDARD_MODE 100000
146#define FAST_MODE 400000
147
148/* Register offsets */
149#define ICDR 0x00
150#define ICCR 0x04
151#define ICSR 0x08
152#define ICIC 0x0c
153#define ICCL 0x10
154#define ICCH 0x14
155
156/* Register bits */
157#define ICCR_ICE 0x80
158#define ICCR_RACK 0x40
159#define ICCR_TRS 0x10
160#define ICCR_BBSY 0x04
161#define ICCR_SCP 0x01
162
163#define ICSR_SCLM 0x80
164#define ICSR_SDAM 0x40
165#define SW_DONE 0x20
166#define ICSR_BUSY 0x10
167#define ICSR_AL 0x08
168#define ICSR_TACK 0x04
169#define ICSR_WAIT 0x02
170#define ICSR_DTE 0x01
171
172#define ICIC_ICCLB8 0x80
173#define ICIC_ICCHB8 0x40
174#define ICIC_ALE 0x08
175#define ICIC_TACKE 0x04
176#define ICIC_WAITE 0x02
177#define ICIC_DTEE 0x01
178
179static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data)
180{
181 if (offs == ICIC)
182 data |= pd->icic;
183
184 iowrite8(data, pd->reg + offs);
185}
186
187static unsigned char iic_rd(struct sh_mobile_i2c_data *pd, int offs)
188{
189 return ioread8(pd->reg + offs);
190}
191
192static void iic_set_clr(struct sh_mobile_i2c_data *pd, int offs,
193 unsigned char set, unsigned char clr)
194{
195 iic_wr(pd, offs, (iic_rd(pd, offs) | set) & ~clr);
196}
197
198static u32 sh_mobile_i2c_iccl(unsigned long count_khz, u32 tLOW, u32 tf, int offset)
199{
200 /*
201 * Conditional expression:
202 * ICCL >= COUNT_CLK * (tLOW + tf)
203 *
204 * SH-Mobile IIC hardware starts counting the LOW period of
205 * the SCL signal (tLOW) as soon as it pulls the SCL line.
206 * In order to meet the tLOW timing spec, we need to take into
207 * account the fall time of SCL signal (tf). Default tf value
208 * should be 0.3 us, for safety.
209 */
210 return (((count_khz * (tLOW + tf)) + 5000) / 10000) + offset;
211}
212
213static u32 sh_mobile_i2c_icch(unsigned long count_khz, u32 tHIGH, u32 tf, int offset)
214{
215 /*
216 * Conditional expression:
217 * ICCH >= COUNT_CLK * (tHIGH + tf)
218 *
219 * SH-Mobile IIC hardware is aware of SCL transition period 'tr',
220 * and can ignore it. SH-Mobile IIC controller starts counting
221 * the HIGH period of the SCL signal (tHIGH) after the SCL input
222 * voltage increases at VIH.
223 *
224 * Afterward it turned out calculating ICCH using only tHIGH spec
225 * will result in violation of the tHD;STA timing spec. We need
226 * to take into account the fall time of SDA signal (tf) at START
227 * condition, in order to meet both tHIGH and tHD;STA specs.
228 */
229 return (((count_khz * (tHIGH + tf)) + 5000) / 10000) + offset;
230}
231
232static void sh_mobile_i2c_init(struct sh_mobile_i2c_data *pd)
233{
234 unsigned long i2c_clk_khz;
235 u32 tHIGH, tLOW, tf;
236 int offset;
237
238 /* Get clock rate after clock is enabled */
239 clk_enable(pd->clk);
240 i2c_clk_khz = clk_get_rate(pd->clk) / 1000;
241 i2c_clk_khz /= pd->clks_per_count;
242
243 if (pd->bus_speed == STANDARD_MODE) {
244 tLOW = 47; /* tLOW = 4.7 us */
245 tHIGH = 40; /* tHD;STA = tHIGH = 4.0 us */
246 tf = 3; /* tf = 0.3 us */
247 offset = 0; /* No offset */
248 } else if (pd->bus_speed == FAST_MODE) {
249 tLOW = 13; /* tLOW = 1.3 us */
250 tHIGH = 6; /* tHD;STA = tHIGH = 0.6 us */
251 tf = 3; /* tf = 0.3 us */
252 offset = 0; /* No offset */
253 } else {
254 dev_err(pd->dev, "unrecognized bus speed %lu Hz\n",
255 pd->bus_speed);
256 goto out;
257 }
258
259 pd->iccl = sh_mobile_i2c_iccl(i2c_clk_khz, tLOW, tf, offset);
260 /* one more bit of ICCL in ICIC */
261 if ((pd->iccl > 0xff) && (pd->flags & IIC_FLAG_HAS_ICIC67))
262 pd->icic |= ICIC_ICCLB8;
263 else
264 pd->icic &= ~ICIC_ICCLB8;
265
266 pd->icch = sh_mobile_i2c_icch(i2c_clk_khz, tHIGH, tf, offset);
267 /* one more bit of ICCH in ICIC */
268 if ((pd->icch > 0xff) && (pd->flags & IIC_FLAG_HAS_ICIC67))
269 pd->icic |= ICIC_ICCHB8;
270 else
271 pd->icic &= ~ICIC_ICCHB8;
272
273out:
274 clk_disable(pd->clk);
275}
276
277static void activate_ch(struct sh_mobile_i2c_data *pd)
278{
279 /* Wake up device and enable clock */
280 pm_runtime_get_sync(pd->dev);
281 clk_enable(pd->clk);
282
283 /* Enable channel and configure rx ack */
284 iic_set_clr(pd, ICCR, ICCR_ICE, 0);
285
286 /* Mask all interrupts */
287 iic_wr(pd, ICIC, 0);
288
289 /* Set the clock */
290 iic_wr(pd, ICCL, pd->iccl & 0xff);
291 iic_wr(pd, ICCH, pd->icch & 0xff);
292}
293
294static void deactivate_ch(struct sh_mobile_i2c_data *pd)
295{
296 /* Clear/disable interrupts */
297 iic_wr(pd, ICSR, 0);
298 iic_wr(pd, ICIC, 0);
299
300 /* Disable channel */
301 iic_set_clr(pd, ICCR, 0, ICCR_ICE);
302
303 /* Disable clock and mark device as idle */
304 clk_disable(pd->clk);
305 pm_runtime_put_sync(pd->dev);
306}
307
308static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
309 enum sh_mobile_i2c_op op, unsigned char data)
310{
311 unsigned char ret = 0;
312 unsigned long flags;
313
314 dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data);
315
316 spin_lock_irqsave(&pd->lock, flags);
317
318 switch (op) {
319 case OP_START: /* issue start and trigger DTE interrupt */
320 iic_wr(pd, ICCR, 0x94);
321 break;
322 case OP_TX_FIRST: /* disable DTE interrupt and write data */
323 iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
324 iic_wr(pd, ICDR, data);
325 break;
326 case OP_TX: /* write data */
327 iic_wr(pd, ICDR, data);
328 break;
329 case OP_TX_STOP: /* write data and issue a stop afterwards */
330 iic_wr(pd, ICDR, data);
331 iic_wr(pd, ICCR, pd->send_stop ? 0x90 : 0x94);
332 break;
333 case OP_TX_TO_RX: /* select read mode */
334 iic_wr(pd, ICCR, 0x81);
335 break;
336 case OP_RX: /* just read data */
337 ret = iic_rd(pd, ICDR);
338 break;
339 case OP_RX_STOP: /* enable DTE interrupt, issue stop */
340 iic_wr(pd, ICIC,
341 ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
342 iic_wr(pd, ICCR, 0xc0);
343 break;
344 case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */
345 iic_wr(pd, ICIC,
346 ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
347 ret = iic_rd(pd, ICDR);
348 iic_wr(pd, ICCR, 0xc0);
349 break;
350 }
351
352 spin_unlock_irqrestore(&pd->lock, flags);
353
354 dev_dbg(pd->dev, "op %d, data out 0x%02x\n", op, ret);
355 return ret;
356}
357
358static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
359{
360 return pd->pos == -1;
361}
362
363static bool sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd)
364{
365 return pd->pos == pd->msg->len - 1;
366}
367
368static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd,
369 unsigned char *buf)
370{
371 switch (pd->pos) {
372 case -1:
373 *buf = (pd->msg->addr & 0x7f) << 1;
374 *buf |= (pd->msg->flags & I2C_M_RD) ? 1 : 0;
375 break;
376 default:
377 *buf = pd->msg->buf[pd->pos];
378 }
379}
380
381static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
382{
383 unsigned char data;
384
385 if (pd->pos == pd->msg->len)
386 return 1;
387
388 sh_mobile_i2c_get_data(pd, &data);
389
390 if (sh_mobile_i2c_is_last_byte(pd))
391 i2c_op(pd, OP_TX_STOP, data);
392 else if (sh_mobile_i2c_is_first_byte(pd))
393 i2c_op(pd, OP_TX_FIRST, data);
394 else
395 i2c_op(pd, OP_TX, data);
396
397 pd->pos++;
398 return 0;
399}
400
401static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
402{
403 unsigned char data;
404 int real_pos;
405
406 do {
407 if (pd->pos <= -1) {
408 sh_mobile_i2c_get_data(pd, &data);
409
410 if (sh_mobile_i2c_is_first_byte(pd))
411 i2c_op(pd, OP_TX_FIRST, data);
412 else
413 i2c_op(pd, OP_TX, data);
414 break;
415 }
416
417 if (pd->pos == 0) {
418 i2c_op(pd, OP_TX_TO_RX, 0);
419 break;
420 }
421
422 real_pos = pd->pos - 2;
423
424 if (pd->pos == pd->msg->len) {
425 if (real_pos < 0) {
426 i2c_op(pd, OP_RX_STOP, 0);
427 break;
428 }
429 data = i2c_op(pd, OP_RX_STOP_DATA, 0);
430 } else
431 data = i2c_op(pd, OP_RX, 0);
432
433 if (real_pos >= 0)
434 pd->msg->buf[real_pos] = data;
435 } while (0);
436
437 pd->pos++;
438 return pd->pos == (pd->msg->len + 2);
439}
440
441static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
442{
443 struct platform_device *dev = dev_id;
444 struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
445 unsigned char sr;
446 int wakeup;
447
448 sr = iic_rd(pd, ICSR);
449 pd->sr |= sr; /* remember state */
450
451 dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr,
452 (pd->msg->flags & I2C_M_RD) ? "read" : "write",
453 pd->pos, pd->msg->len);
454
455 if (sr & (ICSR_AL | ICSR_TACK)) {
456 /* don't interrupt transaction - continue to issue stop */
457 iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK));
458 wakeup = 0;
459 } else if (pd->msg->flags & I2C_M_RD)
460 wakeup = sh_mobile_i2c_isr_rx(pd);
461 else
462 wakeup = sh_mobile_i2c_isr_tx(pd);
463
464 if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */
465 iic_wr(pd, ICSR, sr & ~ICSR_WAIT);
466
467 if (wakeup) {
468 pd->sr |= SW_DONE;
469 wake_up(&pd->wait);
470 }
471
472 /* defeat write posting to avoid spurious WAIT interrupts */
473 iic_rd(pd, ICSR);
474
475 return IRQ_HANDLED;
476}
477
478static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
479 bool do_init)
480{
481 if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
482 dev_err(pd->dev, "Unsupported zero length i2c read\n");
483 return -EIO;
484 }
485
486 if (do_init) {
487 /* Initialize channel registers */
488 iic_set_clr(pd, ICCR, 0, ICCR_ICE);
489
490 /* Enable channel and configure rx ack */
491 iic_set_clr(pd, ICCR, ICCR_ICE, 0);
492
493 /* Set the clock */
494 iic_wr(pd, ICCL, pd->iccl & 0xff);
495 iic_wr(pd, ICCH, pd->icch & 0xff);
496 }
497
498 pd->msg = usr_msg;
499 pd->pos = -1;
500 pd->sr = 0;
501
502 /* Enable all interrupts to begin with */
503 iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
504 return 0;
505}
506
507static int poll_dte(struct sh_mobile_i2c_data *pd)
508{
509 int i;
510
511 for (i = 1000; i; i--) {
512 u_int8_t val = iic_rd(pd, ICSR);
513
514 if (val & ICSR_DTE)
515 break;
516
517 if (val & ICSR_TACK)
518 return -EIO;
519
520 udelay(10);
521 }
522
523 if (!i) {
524 dev_warn(pd->dev, "Timeout polling for DTE!\n");
525 return -ETIMEDOUT;
526 }
527
528 return 0;
529}
530
531static int poll_busy(struct sh_mobile_i2c_data *pd)
532{
533 int i;
534
535 for (i = 1000; i; i--) {
536 u_int8_t val = iic_rd(pd, ICSR);
537
538 dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr);
539
540 /* the interrupt handler may wake us up before the
541 * transfer is finished, so poll the hardware
542 * until we're done.
543 */
544 if (!(val & ICSR_BUSY)) {
545 /* handle missing acknowledge and arbitration lost */
546 if ((val | pd->sr) & (ICSR_TACK | ICSR_AL))
547 return -EIO;
548 break;
549 }
550
551 udelay(10);
552 }
553
554 if (!i) {
555 dev_err(pd->dev, "Polling timed out\n");
556 return -ETIMEDOUT;
557 }
558
559 return 0;
560}
561
562static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
563 struct i2c_msg *msgs,
564 int num)
565{
566 struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
567 struct i2c_msg *msg;
568 int err = 0;
569 int i, k;
570
571 activate_ch(pd);
572
573 /* Process all messages */
574 for (i = 0; i < num; i++) {
575 bool do_start = pd->send_stop || !i;
576 msg = &msgs[i];
577 pd->send_stop = i == num - 1 || msg->flags & I2C_M_STOP;
578
579 err = start_ch(pd, msg, do_start);
580 if (err)
581 break;
582
583 if (do_start)
584 i2c_op(pd, OP_START, 0);
585
586 /* The interrupt handler takes care of the rest... */
587 k = wait_event_timeout(pd->wait,
588 pd->sr & (ICSR_TACK | SW_DONE),
589 5 * HZ);
590 if (!k) {
591 dev_err(pd->dev, "Transfer request timed out\n");
592 err = -ETIMEDOUT;
593 break;
594 }
595
596 if (pd->send_stop)
597 err = poll_busy(pd);
598 else
599 err = poll_dte(pd);
600 if (err < 0)
601 break;
602 }
603
604 deactivate_ch(pd);
605
606 if (!err)
607 err = num;
608 return err;
609}
610
611static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
612{
613 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
614}
615
616static struct i2c_algorithm sh_mobile_i2c_algorithm = {
617 .functionality = sh_mobile_i2c_func,
618 .master_xfer = sh_mobile_i2c_xfer,
619};
620
621static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, int hook)
622{
623 struct resource *res;
624 int ret = -ENXIO;
625 int n, k = 0;
626
627 while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
628 for (n = res->start; hook && n <= res->end; n++) {
629 if (request_irq(n, sh_mobile_i2c_isr, 0,
630 dev_name(&dev->dev), dev)) {
631 for (n--; n >= res->start; n--)
632 free_irq(n, dev);
633
634 goto rollback;
635 }
636 }
637 k++;
638 }
639
640 if (hook)
641 return k > 0 ? 0 : -ENOENT;
642
643 ret = 0;
644
645 rollback:
646 k--;
647
648 while (k >= 0) {
649 res = platform_get_resource(dev, IORESOURCE_IRQ, k);
650 for (n = res->start; n <= res->end; n++)
651 free_irq(n, dev);
652
653 k--;
654 }
655
656 return ret;
657}
658
659static int sh_mobile_i2c_probe(struct platform_device *dev)
660{
661 struct i2c_sh_mobile_platform_data *pdata = dev->dev.platform_data;
662 struct sh_mobile_i2c_data *pd;
663 struct i2c_adapter *adap;
664 struct resource *res;
665 int size;
666 int ret;
667
668 pd = kzalloc(sizeof(struct sh_mobile_i2c_data), GFP_KERNEL);
669 if (pd == NULL) {
670 dev_err(&dev->dev, "cannot allocate private data\n");
671 return -ENOMEM;
672 }
673
674 pd->clk = clk_get(&dev->dev, NULL);
675 if (IS_ERR(pd->clk)) {
676 dev_err(&dev->dev, "cannot get clock\n");
677 ret = PTR_ERR(pd->clk);
678 goto err;
679 }
680
681 ret = sh_mobile_i2c_hook_irqs(dev, 1);
682 if (ret) {
683 dev_err(&dev->dev, "cannot request IRQ\n");
684 goto err_clk;
685 }
686
687 pd->dev = &dev->dev;
688 platform_set_drvdata(dev, pd);
689
690 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
691 if (res == NULL) {
692 dev_err(&dev->dev, "cannot find IO resource\n");
693 ret = -ENOENT;
694 goto err_irq;
695 }
696
697 size = resource_size(res);
698
699 pd->reg = ioremap(res->start, size);
700 if (pd->reg == NULL) {
701 dev_err(&dev->dev, "cannot map IO\n");
702 ret = -ENXIO;
703 goto err_irq;
704 }
705
706 /* Use platform data bus speed or STANDARD_MODE */
707 pd->bus_speed = STANDARD_MODE;
708 if (pdata && pdata->bus_speed)
709 pd->bus_speed = pdata->bus_speed;
710 pd->clks_per_count = 1;
711 if (pdata && pdata->clks_per_count)
712 pd->clks_per_count = pdata->clks_per_count;
713
714 /* The IIC blocks on SH-Mobile ARM processors
715 * come with two new bits in ICIC.
716 */
717 if (size > 0x17)
718 pd->flags |= IIC_FLAG_HAS_ICIC67;
719
720 sh_mobile_i2c_init(pd);
721
722 /* Enable Runtime PM for this device.
723 *
724 * Also tell the Runtime PM core to ignore children
725 * for this device since it is valid for us to suspend
726 * this I2C master driver even though the slave devices
727 * on the I2C bus may not be suspended.
728 *
729 * The state of the I2C hardware bus is unaffected by
730 * the Runtime PM state.
731 */
732 pm_suspend_ignore_children(&dev->dev, true);
733 pm_runtime_enable(&dev->dev);
734
735 /* setup the private data */
736 adap = &pd->adap;
737 i2c_set_adapdata(adap, pd);
738
739 adap->owner = THIS_MODULE;
740 adap->algo = &sh_mobile_i2c_algorithm;
741 adap->dev.parent = &dev->dev;
742 adap->retries = 5;
743 adap->nr = dev->id;
744 adap->dev.of_node = dev->dev.of_node;
745
746 strlcpy(adap->name, dev->name, sizeof(adap->name));
747
748 spin_lock_init(&pd->lock);
749 init_waitqueue_head(&pd->wait);
750
751 ret = i2c_add_numbered_adapter(adap);
752 if (ret < 0) {
753 dev_err(&dev->dev, "cannot add numbered adapter\n");
754 goto err_all;
755 }
756
757 dev_info(&dev->dev,
758 "I2C adapter %d with bus speed %lu Hz (L/H=%x/%x)\n",
759 adap->nr, pd->bus_speed, pd->iccl, pd->icch);
760
761 of_i2c_register_devices(adap);
762 return 0;
763
764 err_all:
765 iounmap(pd->reg);
766 err_irq:
767 sh_mobile_i2c_hook_irqs(dev, 0);
768 err_clk:
769 clk_put(pd->clk);
770 err:
771 kfree(pd);
772 return ret;
773}
774
775static int sh_mobile_i2c_remove(struct platform_device *dev)
776{
777 struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
778
779 i2c_del_adapter(&pd->adap);
780 iounmap(pd->reg);
781 sh_mobile_i2c_hook_irqs(dev, 0);
782 clk_put(pd->clk);
783 pm_runtime_disable(&dev->dev);
784 kfree(pd);
785 return 0;
786}
787
788static int sh_mobile_i2c_runtime_nop(struct device *dev)
789{
790 /* Runtime PM callback shared between ->runtime_suspend()
791 * and ->runtime_resume(). Simply returns success.
792 *
793 * This driver re-initializes all registers after
794 * pm_runtime_get_sync() anyway so there is no need
795 * to save and restore registers here.
796 */
797 return 0;
798}
799
800static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = {
801 .runtime_suspend = sh_mobile_i2c_runtime_nop,
802 .runtime_resume = sh_mobile_i2c_runtime_nop,
803};
804
805static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
806 { .compatible = "renesas,rmobile-iic", },
807 {},
808};
809MODULE_DEVICE_TABLE(of, sh_mobile_i2c_dt_ids);
810
811static struct platform_driver sh_mobile_i2c_driver = {
812 .driver = {
813 .name = "i2c-sh_mobile",
814 .owner = THIS_MODULE,
815 .pm = &sh_mobile_i2c_dev_pm_ops,
816 .of_match_table = sh_mobile_i2c_dt_ids,
817 },
818 .probe = sh_mobile_i2c_probe,
819 .remove = sh_mobile_i2c_remove,
820};
821
822static int __init sh_mobile_i2c_adap_init(void)
823{
824 return platform_driver_register(&sh_mobile_i2c_driver);
825}
826
827static void __exit sh_mobile_i2c_adap_exit(void)
828{
829 platform_driver_unregister(&sh_mobile_i2c_driver);
830}
831
832subsys_initcall(sh_mobile_i2c_adap_init);
833module_exit(sh_mobile_i2c_adap_exit);
834
835MODULE_DESCRIPTION("SuperH Mobile I2C Bus Controller driver");
836MODULE_AUTHOR("Magnus Damm");
837MODULE_LICENSE("GPL v2");
838MODULE_ALIAS("platform:i2c-sh_mobile");