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mce: fix warning messages about static struct mce_device
[linux-2.6.git] / drivers / i2c / busses / i2c-sh_mobile.c
blob675c9692d14860553bbdb03154e5fd88a5e7526f
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/err.h>
31 #include <linux/pm_runtime.h>
32 #include <linux/clk.h>
33 #include <linux/io.h>
34 #include <linux/slab.h>
35 #include <linux/i2c/i2c-sh_mobile.h>
36
37 /* Transmit operation: */
38 /* */
39 /* 0 byte transmit */
40 /* BUS: S A8 ACK P */
41 /* IRQ: DTE WAIT */
42 /* ICIC: */
43 /* ICCR: 0x94 0x90 */
44 /* ICDR: A8 */
45 /* */
46 /* 1 byte transmit */
47 /* BUS: S A8 ACK D8(1) ACK P */
48 /* IRQ: DTE WAIT WAIT */
49 /* ICIC: -DTE */
50 /* ICCR: 0x94 0x90 */
51 /* ICDR: A8 D8(1) */
52 /* */
53 /* 2 byte transmit */
54 /* BUS: S A8 ACK D8(1) ACK D8(2) ACK P */
55 /* IRQ: DTE WAIT WAIT WAIT */
56 /* ICIC: -DTE */
57 /* ICCR: 0x94 0x90 */
58 /* ICDR: A8 D8(1) D8(2) */
59 /* */
60 /* 3 bytes or more, +---------+ gets repeated */
61 /* */
62 /* */
63 /* Receive operation: */
64 /* */
65 /* 0 byte receive - not supported since slave may hold SDA low */
66 /* */
67 /* 1 byte receive [TX] | [RX] */
68 /* BUS: S A8 ACK | D8(1) ACK P */
69 /* IRQ: DTE WAIT | WAIT DTE */
70 /* ICIC: -DTE | +DTE */
71 /* ICCR: 0x94 0x81 | 0xc0 */
72 /* ICDR: A8 | D8(1) */
73 /* */
74 /* 2 byte receive [TX]| [RX] */
75 /* BUS: S A8 ACK | D8(1) ACK D8(2) ACK P */
76 /* IRQ: DTE WAIT | WAIT WAIT DTE */
77 /* ICIC: -DTE | +DTE */
78 /* ICCR: 0x94 0x81 | 0xc0 */
79 /* ICDR: A8 | D8(1) D8(2) */
80 /* */
81 /* 3 byte receive [TX] | [RX] */
82 /* BUS: S A8 ACK | D8(1) ACK D8(2) ACK D8(3) ACK P */
83 /* IRQ: DTE WAIT | WAIT WAIT WAIT DTE */
84 /* ICIC: -DTE | +DTE */
85 /* ICCR: 0x94 0x81 | 0xc0 */
86 /* ICDR: A8 | D8(1) D8(2) D8(3) */
87 /* */
88 /* 4 bytes or more, this part is repeated +---------+ */
89 /* */
90 /* */
91 /* Interrupt order and BUSY flag */
92 /* ___ _ */
93 /* SDA ___\___XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXAAAAAAAAA___/ */
94 /* SCL \_/1\_/2\_/3\_/4\_/5\_/6\_/7\_/8\___/9\_____/ */
95 /* */
96 /* S D7 D6 D5 D4 D3 D2 D1 D0 P */
97 /* ___ */
98 /* WAIT IRQ ________________________________/ \___________ */
99 /* TACK IRQ ____________________________________/ \_______ */
100 /* DTE IRQ __________________________________________/ \_ */
101 /* AL IRQ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
102 /* _______________________________________________ */
103 /* BUSY __/ \_ */
104 /* */
105
106 enum sh_mobile_i2c_op {
107 OP_START = 0,
108 OP_TX_FIRST,
109 OP_TX,
110 OP_TX_STOP,
111 OP_TX_TO_RX,
112 OP_RX,
113 OP_RX_STOP,
114 OP_RX_STOP_DATA,
115 };
116
117 struct sh_mobile_i2c_data {
118 struct device *dev;
119 void __iomem *reg;
120 struct i2c_adapter adap;
121 unsigned long bus_speed;
122 struct clk *clk;
123 u_int8_t icic;
124 u_int8_t iccl;
125 u_int8_t icch;
126 u_int8_t flags;
127
128 spinlock_t lock;
129 wait_queue_head_t wait;
130 struct i2c_msg *msg;
131 int pos;
132 int sr;
133 };
134
135 #define IIC_FLAG_HAS_ICIC67 (1 << 0)
136
137 #define NORMAL_SPEED 100000 /* FAST_SPEED 400000 */
138
139 /* Register offsets */
140 #define ICDR 0x00
141 #define ICCR 0x04
142 #define ICSR 0x08
143 #define ICIC 0x0c
144 #define ICCL 0x10
145 #define ICCH 0x14
146
147 /* Register bits */
148 #define ICCR_ICE 0x80
149 #define ICCR_RACK 0x40
150 #define ICCR_TRS 0x10
151 #define ICCR_BBSY 0x04
152 #define ICCR_SCP 0x01
153
154 #define ICSR_SCLM 0x80
155 #define ICSR_SDAM 0x40
156 #define SW_DONE 0x20
157 #define ICSR_BUSY 0x10
158 #define ICSR_AL 0x08
159 #define ICSR_TACK 0x04
160 #define ICSR_WAIT 0x02
161 #define ICSR_DTE 0x01
162
163 #define ICIC_ICCLB8 0x80
164 #define ICIC_ICCHB8 0x40
165 #define ICIC_ALE 0x08
166 #define ICIC_TACKE 0x04
167 #define ICIC_WAITE 0x02
168 #define ICIC_DTEE 0x01
169
170 static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data)
171 {
172 if (offs == ICIC)
173 data |= pd->icic;
174
175 iowrite8(data, pd->reg + offs);
176 }
177
178 static unsigned char iic_rd(struct sh_mobile_i2c_data *pd, int offs)
179 {
180 return ioread8(pd->reg + offs);
181 }
182
183 static void iic_set_clr(struct sh_mobile_i2c_data *pd, int offs,
184 unsigned char set, unsigned char clr)
185 {
186 iic_wr(pd, offs, (iic_rd(pd, offs) | set) & ~clr);
187 }
188
189 static void activate_ch(struct sh_mobile_i2c_data *pd)
190 {
191 unsigned long i2c_clk;
192 u_int32_t num;
193 u_int32_t denom;
194 u_int32_t tmp;
195
196 /* Wake up device and enable clock */
197 pm_runtime_get_sync(pd->dev);
198 clk_enable(pd->clk);
199
200 /* Get clock rate after clock is enabled */
201 i2c_clk = clk_get_rate(pd->clk);
202
203 /* Calculate the value for iccl. From the data sheet:
204 * iccl = (p clock / transfer rate) * (L / (L + H))
205 * where L and H are the SCL low/high ratio (5/4 in this case).
206 * We also round off the result.
207 */
208 num = i2c_clk * 5;
209 denom = pd->bus_speed * 9;
210 tmp = num * 10 / denom;
211 if (tmp % 10 >= 5)
212 pd->iccl = (u_int8_t)((num/denom) + 1);
213 else
214 pd->iccl = (u_int8_t)(num/denom);
215
216 /* one more bit of ICCL in ICIC */
217 if (pd->flags & IIC_FLAG_HAS_ICIC67) {
218 if ((num/denom) > 0xff)
219 pd->icic |= ICIC_ICCLB8;
220 else
221 pd->icic &= ~ICIC_ICCLB8;
222 }
223
224 /* Calculate the value for icch. From the data sheet:
225 icch = (p clock / transfer rate) * (H / (L + H)) */
226 num = i2c_clk * 4;
227 tmp = num * 10 / denom;
228 if (tmp % 10 >= 5)
229 pd->icch = (u_int8_t)((num/denom) + 1);
230 else
231 pd->icch = (u_int8_t)(num/denom);
232
233 /* one more bit of ICCH in ICIC */
234 if (pd->flags & IIC_FLAG_HAS_ICIC67) {
235 if ((num/denom) > 0xff)
236 pd->icic |= ICIC_ICCHB8;
237 else
238 pd->icic &= ~ICIC_ICCHB8;
239 }
240
241 /* Enable channel and configure rx ack */
242 iic_set_clr(pd, ICCR, ICCR_ICE, 0);
243
244 /* Mask all interrupts */
245 iic_wr(pd, ICIC, 0);
246
247 /* Set the clock */
248 iic_wr(pd, ICCL, pd->iccl);
249 iic_wr(pd, ICCH, pd->icch);
250 }
251
252 static void deactivate_ch(struct sh_mobile_i2c_data *pd)
253 {
254 /* Clear/disable interrupts */
255 iic_wr(pd, ICSR, 0);
256 iic_wr(pd, ICIC, 0);
257
258 /* Disable channel */
259 iic_set_clr(pd, ICCR, 0, ICCR_ICE);
260
261 /* Disable clock and mark device as idle */
262 clk_disable(pd->clk);
263 pm_runtime_put_sync(pd->dev);
264 }
265
266 static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
267 enum sh_mobile_i2c_op op, unsigned char data)
268 {
269 unsigned char ret = 0;
270 unsigned long flags;
271
272 dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data);
273
274 spin_lock_irqsave(&pd->lock, flags);
275
276 switch (op) {
277 case OP_START: /* issue start and trigger DTE interrupt */
278 iic_wr(pd, ICCR, 0x94);
279 break;
280 case OP_TX_FIRST: /* disable DTE interrupt and write data */
281 iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
282 iic_wr(pd, ICDR, data);
283 break;
284 case OP_TX: /* write data */
285 iic_wr(pd, ICDR, data);
286 break;
287 case OP_TX_STOP: /* write data and issue a stop afterwards */
288 iic_wr(pd, ICDR, data);
289 iic_wr(pd, ICCR, 0x90);
290 break;
291 case OP_TX_TO_RX: /* select read mode */
292 iic_wr(pd, ICCR, 0x81);
293 break;
294 case OP_RX: /* just read data */
295 ret = iic_rd(pd, ICDR);
296 break;
297 case OP_RX_STOP: /* enable DTE interrupt, issue stop */
298 iic_wr(pd, ICIC,
299 ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
300 iic_wr(pd, ICCR, 0xc0);
301 break;
302 case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */
303 iic_wr(pd, ICIC,
304 ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
305 ret = iic_rd(pd, ICDR);
306 iic_wr(pd, ICCR, 0xc0);
307 break;
308 }
309
310 spin_unlock_irqrestore(&pd->lock, flags);
311
312 dev_dbg(pd->dev, "op %d, data out 0x%02x\n", op, ret);
313 return ret;
314 }
315
316 static int sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
317 {
318 if (pd->pos == -1)
319 return 1;
320
321 return 0;
322 }
323
324 static int sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd)
325 {
326 if (pd->pos == (pd->msg->len - 1))
327 return 1;
328
329 return 0;
330 }
331
332 static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd,
333 unsigned char *buf)
334 {
335 switch (pd->pos) {
336 case -1:
337 *buf = (pd->msg->addr & 0x7f) << 1;
338 *buf |= (pd->msg->flags & I2C_M_RD) ? 1 : 0;
339 break;
340 default:
341 *buf = pd->msg->buf[pd->pos];
342 }
343 }
344
345 static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
346 {
347 unsigned char data;
348
349 if (pd->pos == pd->msg->len)
350 return 1;
351
352 sh_mobile_i2c_get_data(pd, &data);
353
354 if (sh_mobile_i2c_is_last_byte(pd))
355 i2c_op(pd, OP_TX_STOP, data);
356 else if (sh_mobile_i2c_is_first_byte(pd))
357 i2c_op(pd, OP_TX_FIRST, data);
358 else
359 i2c_op(pd, OP_TX, data);
360
361 pd->pos++;
362 return 0;
363 }
364
365 static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
366 {
367 unsigned char data;
368 int real_pos;
369
370 do {
371 if (pd->pos <= -1) {
372 sh_mobile_i2c_get_data(pd, &data);
373
374 if (sh_mobile_i2c_is_first_byte(pd))
375 i2c_op(pd, OP_TX_FIRST, data);
376 else
377 i2c_op(pd, OP_TX, data);
378 break;
379 }
380
381 if (pd->pos == 0) {
382 i2c_op(pd, OP_TX_TO_RX, 0);
383 break;
384 }
385
386 real_pos = pd->pos - 2;
387
388 if (pd->pos == pd->msg->len) {
389 if (real_pos < 0) {
390 i2c_op(pd, OP_RX_STOP, 0);
391 break;
392 }
393 data = i2c_op(pd, OP_RX_STOP_DATA, 0);
394 } else
395 data = i2c_op(pd, OP_RX, 0);
396
397 if (real_pos >= 0)
398 pd->msg->buf[real_pos] = data;
399 } while (0);
400
401 pd->pos++;
402 return pd->pos == (pd->msg->len + 2);
403 }
404
405 static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
406 {
407 struct platform_device *dev = dev_id;
408 struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
409 unsigned char sr;
410 int wakeup;
411
412 sr = iic_rd(pd, ICSR);
413 pd->sr |= sr; /* remember state */
414
415 dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr,
416 (pd->msg->flags & I2C_M_RD) ? "read" : "write",
417 pd->pos, pd->msg->len);
418
419 if (sr & (ICSR_AL | ICSR_TACK)) {
420 /* don't interrupt transaction - continue to issue stop */
421 iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK));
422 wakeup = 0;
423 } else if (pd->msg->flags & I2C_M_RD)
424 wakeup = sh_mobile_i2c_isr_rx(pd);
425 else
426 wakeup = sh_mobile_i2c_isr_tx(pd);
427
428 if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */
429 iic_wr(pd, ICSR, sr & ~ICSR_WAIT);
430
431 if (wakeup) {
432 pd->sr |= SW_DONE;
433 wake_up(&pd->wait);
434 }
435
436 return IRQ_HANDLED;
437 }
438
439 static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg)
440 {
441 if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
442 dev_err(pd->dev, "Unsupported zero length i2c read\n");
443 return -EIO;
444 }
445
446 /* Initialize channel registers */
447 iic_set_clr(pd, ICCR, 0, ICCR_ICE);
448
449 /* Enable channel and configure rx ack */
450 iic_set_clr(pd, ICCR, ICCR_ICE, 0);
451
452 /* Set the clock */
453 iic_wr(pd, ICCL, pd->iccl);
454 iic_wr(pd, ICCH, pd->icch);
455
456 pd->msg = usr_msg;
457 pd->pos = -1;
458 pd->sr = 0;
459
460 /* Enable all interrupts to begin with */
461 iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
462 return 0;
463 }
464
465 static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
466 struct i2c_msg *msgs,
467 int num)
468 {
469 struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
470 struct i2c_msg *msg;
471 int err = 0;
472 u_int8_t val;
473 int i, k, retry_count;
474
475 activate_ch(pd);
476
477 /* Process all messages */
478 for (i = 0; i < num; i++) {
479 msg = &msgs[i];
480
481 err = start_ch(pd, msg);
482 if (err)
483 break;
484
485 i2c_op(pd, OP_START, 0);
486
487 /* The interrupt handler takes care of the rest... */
488 k = wait_event_timeout(pd->wait,
489 pd->sr & (ICSR_TACK | SW_DONE),
490 5 * HZ);
491 if (!k)
492 dev_err(pd->dev, "Transfer request timed out\n");
493
494 retry_count = 1000;
495 again:
496 val = iic_rd(pd, ICSR);
497
498 dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr);
499
500 /* the interrupt handler may wake us up before the
501 * transfer is finished, so poll the hardware
502 * until we're done.
503 */
504 if (val & ICSR_BUSY) {
505 udelay(10);
506 if (retry_count--)
507 goto again;
508
509 err = -EIO;
510 dev_err(pd->dev, "Polling timed out\n");
511 break;
512 }
513
514 /* handle missing acknowledge and arbitration lost */
515 if ((val | pd->sr) & (ICSR_TACK | ICSR_AL)) {
516 err = -EIO;
517 break;
518 }
519 }
520
521 deactivate_ch(pd);
522
523 if (!err)
524 err = num;
525 return err;
526 }
527
528 static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
529 {
530 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
531 }
532
533 static struct i2c_algorithm sh_mobile_i2c_algorithm = {
534 .functionality = sh_mobile_i2c_func,
535 .master_xfer = sh_mobile_i2c_xfer,
536 };
537
538 static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, int hook)
539 {
540 struct resource *res;
541 int ret = -ENXIO;
542 int n, k = 0;
543
544 while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
545 for (n = res->start; hook && n <= res->end; n++) {
546 if (request_irq(n, sh_mobile_i2c_isr, 0,
547 dev_name(&dev->dev), dev)) {
548 for (n--; n >= res->start; n--)
549 free_irq(n, dev);
550
551 goto rollback;
552 }
553 }
554 k++;
555 }
556
557 if (hook)
558 return k > 0 ? 0 : -ENOENT;
559
560 ret = 0;
561
562 rollback:
563 k--;
564
565 while (k >= 0) {
566 res = platform_get_resource(dev, IORESOURCE_IRQ, k);
567 for (n = res->start; n <= res->end; n++)
568 free_irq(n, dev);
569
570 k--;
571 }
572
573 return ret;
574 }
575
576 static int sh_mobile_i2c_probe(struct platform_device *dev)
577 {
578 struct i2c_sh_mobile_platform_data *pdata = dev->dev.platform_data;
579 struct sh_mobile_i2c_data *pd;
580 struct i2c_adapter *adap;
581 struct resource *res;
582 int size;
583 int ret;
584
585 pd = kzalloc(sizeof(struct sh_mobile_i2c_data), GFP_KERNEL);
586 if (pd == NULL) {
587 dev_err(&dev->dev, "cannot allocate private data\n");
588 return -ENOMEM;
589 }
590
591 pd->clk = clk_get(&dev->dev, NULL);
592 if (IS_ERR(pd->clk)) {
593 dev_err(&dev->dev, "cannot get clock\n");
594 ret = PTR_ERR(pd->clk);
595 goto err;
596 }
597
598 ret = sh_mobile_i2c_hook_irqs(dev, 1);
599 if (ret) {
600 dev_err(&dev->dev, "cannot request IRQ\n");
601 goto err_clk;
602 }
603
604 pd->dev = &dev->dev;
605 platform_set_drvdata(dev, pd);
606
607 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
608 if (res == NULL) {
609 dev_err(&dev->dev, "cannot find IO resource\n");
610 ret = -ENOENT;
611 goto err_irq;
612 }
613
614 size = resource_size(res);
615
616 pd->reg = ioremap(res->start, size);
617 if (pd->reg == NULL) {
618 dev_err(&dev->dev, "cannot map IO\n");
619 ret = -ENXIO;
620 goto err_irq;
621 }
622
623 /* Use platformd data bus speed or NORMAL_SPEED */
624 pd->bus_speed = NORMAL_SPEED;
625 if (pdata && pdata->bus_speed)
626 pd->bus_speed = pdata->bus_speed;
627
628 /* The IIC blocks on SH-Mobile ARM processors
629 * come with two new bits in ICIC.
630 */
631 if (size > 0x17)
632 pd->flags |= IIC_FLAG_HAS_ICIC67;
633
634 /* Enable Runtime PM for this device.
635 *
636 * Also tell the Runtime PM core to ignore children
637 * for this device since it is valid for us to suspend
638 * this I2C master driver even though the slave devices
639 * on the I2C bus may not be suspended.
640 *
641 * The state of the I2C hardware bus is unaffected by
642 * the Runtime PM state.
643 */
644 pm_suspend_ignore_children(&dev->dev, true);
645 pm_runtime_enable(&dev->dev);
646
647 /* setup the private data */
648 adap = &pd->adap;
649 i2c_set_adapdata(adap, pd);
650
651 adap->owner = THIS_MODULE;
652 adap->algo = &sh_mobile_i2c_algorithm;
653 adap->dev.parent = &dev->dev;
654 adap->retries = 5;
655 adap->nr = dev->id;
656
657 strlcpy(adap->name, dev->name, sizeof(adap->name));
658
659 spin_lock_init(&pd->lock);
660 init_waitqueue_head(&pd->wait);
661
662 ret = i2c_add_numbered_adapter(adap);
663 if (ret < 0) {
664 dev_err(&dev->dev, "cannot add numbered adapter\n");
665 goto err_all;
666 }
667
668 dev_info(&dev->dev, "I2C adapter %d with bus speed %lu Hz\n",
669 adap->nr, pd->bus_speed);
670 return 0;
671
672 err_all:
673 iounmap(pd->reg);
674 err_irq:
675 sh_mobile_i2c_hook_irqs(dev, 0);
676 err_clk:
677 clk_put(pd->clk);
678 err:
679 kfree(pd);
680 return ret;
681 }
682
683 static int sh_mobile_i2c_remove(struct platform_device *dev)
684 {
685 struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
686
687 i2c_del_adapter(&pd->adap);
688 iounmap(pd->reg);
689 sh_mobile_i2c_hook_irqs(dev, 0);
690 clk_put(pd->clk);
691 pm_runtime_disable(&dev->dev);
692 kfree(pd);
693 return 0;
694 }
695
696 static int sh_mobile_i2c_runtime_nop(struct device *dev)
697 {
698 /* Runtime PM callback shared between ->runtime_suspend()
699 * and ->runtime_resume(). Simply returns success.
700 *
701 * This driver re-initializes all registers after
702 * pm_runtime_get_sync() anyway so there is no need
703 * to save and restore registers here.
704 */
705 return 0;
706 }
707
708 static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = {
709 .runtime_suspend = sh_mobile_i2c_runtime_nop,
710 .runtime_resume = sh_mobile_i2c_runtime_nop,
711 };
712
713 static struct platform_driver sh_mobile_i2c_driver = {
714 .driver = {
715 .name = "i2c-sh_mobile",
716 .owner = THIS_MODULE,
717 .pm = &sh_mobile_i2c_dev_pm_ops,
718 },
719 .probe = sh_mobile_i2c_probe,
720 .remove = sh_mobile_i2c_remove,
721 };
722
723 static int __init sh_mobile_i2c_adap_init(void)
724 {
725 return platform_driver_register(&sh_mobile_i2c_driver);
726 }
727
728 static void __exit sh_mobile_i2c_adap_exit(void)
729 {
730 platform_driver_unregister(&sh_mobile_i2c_driver);
731 }
732
733 subsys_initcall(sh_mobile_i2c_adap_init);
734 module_exit(sh_mobile_i2c_adap_exit);
735
736 MODULE_DESCRIPTION("SuperH Mobile I2C Bus Controller driver");
737 MODULE_AUTHOR("Magnus Damm");
738 MODULE_LICENSE("GPL v2");
739 MODULE_ALIAS("platform:i2c-sh_mobile");
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