xref: /openbmc/linux/drivers/i2c/busses/i2c-rcar.c (revision 976fa9a3)
1 /*
2  * Driver for the Renesas RCar I2C unit
3  *
4  * Copyright (C) 2014 Wolfram Sang <wsa@sang-engineering.com>
5  *
6  * Copyright (C) 2012-14 Renesas Solutions Corp.
7  * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
8  *
9  * This file is based on the drivers/i2c/busses/i2c-sh7760.c
10  * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com>
11  *
12  * This file used out-of-tree driver i2c-rcar.c
13  * Copyright (C) 2011-2012 Renesas Electronics Corporation
14  *
15  * This program is free software; you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; version 2 of the License.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  */
24 #include <linux/clk.h>
25 #include <linux/delay.h>
26 #include <linux/err.h>
27 #include <linux/interrupt.h>
28 #include <linux/io.h>
29 #include <linux/i2c.h>
30 #include <linux/i2c/i2c-rcar.h>
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/of_device.h>
34 #include <linux/platform_device.h>
35 #include <linux/pm_runtime.h>
36 #include <linux/slab.h>
37 #include <linux/spinlock.h>
38 
39 /* register offsets */
40 #define ICSCR	0x00	/* slave ctrl */
41 #define ICMCR	0x04	/* master ctrl */
42 #define ICSSR	0x08	/* slave status */
43 #define ICMSR	0x0C	/* master status */
44 #define ICSIER	0x10	/* slave irq enable */
45 #define ICMIER	0x14	/* master irq enable */
46 #define ICCCR	0x18	/* clock dividers */
47 #define ICSAR	0x1C	/* slave address */
48 #define ICMAR	0x20	/* master address */
49 #define ICRXTX	0x24	/* data port */
50 
51 /* ICSCR */
52 #define SDBS	(1 << 3)	/* slave data buffer select */
53 #define SIE	(1 << 2)	/* slave interface enable */
54 #define GCAE	(1 << 1)	/* general call address enable */
55 #define FNA	(1 << 0)	/* forced non acknowledgment */
56 
57 /* ICMCR */
58 #define MDBS	(1 << 7)	/* non-fifo mode switch */
59 #define FSCL	(1 << 6)	/* override SCL pin */
60 #define FSDA	(1 << 5)	/* override SDA pin */
61 #define OBPC	(1 << 4)	/* override pins */
62 #define MIE	(1 << 3)	/* master if enable */
63 #define TSBE	(1 << 2)
64 #define FSB	(1 << 1)	/* force stop bit */
65 #define ESG	(1 << 0)	/* en startbit gen */
66 
67 /* ICSSR (also for ICSIER) */
68 #define GCAR	(1 << 6)	/* general call received */
69 #define STM	(1 << 5)	/* slave transmit mode */
70 #define SSR	(1 << 4)	/* stop received */
71 #define SDE	(1 << 3)	/* slave data empty */
72 #define SDT	(1 << 2)	/* slave data transmitted */
73 #define SDR	(1 << 1)	/* slave data received */
74 #define SAR	(1 << 0)	/* slave addr received */
75 
76 /* ICMSR (also for ICMIE) */
77 #define MNR	(1 << 6)	/* nack received */
78 #define MAL	(1 << 5)	/* arbitration lost */
79 #define MST	(1 << 4)	/* sent a stop */
80 #define MDE	(1 << 3)
81 #define MDT	(1 << 2)
82 #define MDR	(1 << 1)
83 #define MAT	(1 << 0)	/* slave addr xfer done */
84 
85 
86 #define RCAR_BUS_PHASE_START	(MDBS | MIE | ESG)
87 #define RCAR_BUS_PHASE_DATA	(MDBS | MIE)
88 #define RCAR_BUS_PHASE_STOP	(MDBS | MIE | FSB)
89 
90 #define RCAR_IRQ_SEND	(MNR | MAL | MST | MAT | MDE)
91 #define RCAR_IRQ_RECV	(MNR | MAL | MST | MAT | MDR)
92 #define RCAR_IRQ_STOP	(MST)
93 
94 #define RCAR_IRQ_ACK_SEND	(~(MAT | MDE) & 0xFF)
95 #define RCAR_IRQ_ACK_RECV	(~(MAT | MDR) & 0xFF)
96 
97 #define ID_LAST_MSG	(1 << 0)
98 #define ID_IOERROR	(1 << 1)
99 #define ID_DONE		(1 << 2)
100 #define ID_ARBLOST	(1 << 3)
101 #define ID_NACK		(1 << 4)
102 
103 enum rcar_i2c_type {
104 	I2C_RCAR_GEN1,
105 	I2C_RCAR_GEN2,
106 };
107 
108 struct rcar_i2c_priv {
109 	void __iomem *io;
110 	struct i2c_adapter adap;
111 	struct i2c_msg	*msg;
112 	struct clk *clk;
113 
114 	spinlock_t lock;
115 	wait_queue_head_t wait;
116 
117 	int pos;
118 	u32 icccr;
119 	u32 flags;
120 	enum rcar_i2c_type devtype;
121 	struct i2c_client *slave;
122 };
123 
124 #define rcar_i2c_priv_to_dev(p)		((p)->adap.dev.parent)
125 #define rcar_i2c_is_recv(p)		((p)->msg->flags & I2C_M_RD)
126 
127 #define rcar_i2c_flags_set(p, f)	((p)->flags |= (f))
128 #define rcar_i2c_flags_has(p, f)	((p)->flags & (f))
129 
130 #define LOOP_TIMEOUT	1024
131 
132 
133 static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
134 {
135 	writel(val, priv->io + reg);
136 }
137 
138 static u32 rcar_i2c_read(struct rcar_i2c_priv *priv, int reg)
139 {
140 	return readl(priv->io + reg);
141 }
142 
143 static void rcar_i2c_init(struct rcar_i2c_priv *priv)
144 {
145 	/* reset master mode */
146 	rcar_i2c_write(priv, ICMIER, 0);
147 	rcar_i2c_write(priv, ICMCR, 0);
148 	rcar_i2c_write(priv, ICMSR, 0);
149 	rcar_i2c_write(priv, ICMAR, 0);
150 }
151 
152 static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
153 {
154 	int i;
155 
156 	for (i = 0; i < LOOP_TIMEOUT; i++) {
157 		/* make sure that bus is not busy */
158 		if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
159 			return 0;
160 		udelay(1);
161 	}
162 
163 	return -EBUSY;
164 }
165 
166 static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
167 				    u32 bus_speed,
168 				    struct device *dev)
169 {
170 	u32 scgd, cdf;
171 	u32 round, ick;
172 	u32 scl;
173 	u32 cdf_width;
174 	unsigned long rate;
175 
176 	switch (priv->devtype) {
177 	case I2C_RCAR_GEN1:
178 		cdf_width = 2;
179 		break;
180 	case I2C_RCAR_GEN2:
181 		cdf_width = 3;
182 		break;
183 	default:
184 		dev_err(dev, "device type error\n");
185 		return -EIO;
186 	}
187 
188 	/*
189 	 * calculate SCL clock
190 	 * see
191 	 *	ICCCR
192 	 *
193 	 * ick	= clkp / (1 + CDF)
194 	 * SCL	= ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
195 	 *
196 	 * ick  : I2C internal clock < 20 MHz
197 	 * ticf : I2C SCL falling time  =  35 ns here
198 	 * tr   : I2C SCL rising  time  = 200 ns here
199 	 * intd : LSI internal delay    =  50 ns here
200 	 * clkp : peripheral_clk
201 	 * F[]  : integer up-valuation
202 	 */
203 	rate = clk_get_rate(priv->clk);
204 	cdf = rate / 20000000;
205 	if (cdf >= 1U << cdf_width) {
206 		dev_err(dev, "Input clock %lu too high\n", rate);
207 		return -EIO;
208 	}
209 	ick = rate / (cdf + 1);
210 
211 	/*
212 	 * it is impossible to calculate large scale
213 	 * number on u32. separate it
214 	 *
215 	 * F[(ticf + tr + intd) * ick]
216 	 *  = F[(35 + 200 + 50)ns * ick]
217 	 *  = F[285 * ick / 1000000000]
218 	 *  = F[(ick / 1000000) * 285 / 1000]
219 	 */
220 	round = (ick + 500000) / 1000000 * 285;
221 	round = (round + 500) / 1000;
222 
223 	/*
224 	 * SCL	= ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
225 	 *
226 	 * Calculation result (= SCL) should be less than
227 	 * bus_speed for hardware safety
228 	 *
229 	 * We could use something along the lines of
230 	 *	div = ick / (bus_speed + 1) + 1;
231 	 *	scgd = (div - 20 - round + 7) / 8;
232 	 *	scl = ick / (20 + (scgd * 8) + round);
233 	 * (not fully verified) but that would get pretty involved
234 	 */
235 	for (scgd = 0; scgd < 0x40; scgd++) {
236 		scl = ick / (20 + (scgd * 8) + round);
237 		if (scl <= bus_speed)
238 			goto scgd_find;
239 	}
240 	dev_err(dev, "it is impossible to calculate best SCL\n");
241 	return -EIO;
242 
243 scgd_find:
244 	dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n",
245 		scl, bus_speed, clk_get_rate(priv->clk), round, cdf, scgd);
246 
247 	/*
248 	 * keep icccr value
249 	 */
250 	priv->icccr = scgd << cdf_width | cdf;
251 
252 	return 0;
253 }
254 
255 static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
256 {
257 	int read = !!rcar_i2c_is_recv(priv);
258 
259 	rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read);
260 	rcar_i2c_write(priv, ICMSR, 0);
261 	rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
262 	rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
263 }
264 
265 /*
266  *		interrupt functions
267  */
268 static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
269 {
270 	struct i2c_msg *msg = priv->msg;
271 
272 	/*
273 	 * FIXME
274 	 * sometimes, unknown interrupt happened.
275 	 * Do nothing
276 	 */
277 	if (!(msr & MDE))
278 		return 0;
279 
280 	/*
281 	 * If address transfer phase finished,
282 	 * goto data phase.
283 	 */
284 	if (msr & MAT)
285 		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
286 
287 	if (priv->pos < msg->len) {
288 		/*
289 		 * Prepare next data to ICRXTX register.
290 		 * This data will go to _SHIFT_ register.
291 		 *
292 		 *    *
293 		 * [ICRXTX] -> [SHIFT] -> [I2C bus]
294 		 */
295 		rcar_i2c_write(priv, ICRXTX, msg->buf[priv->pos]);
296 		priv->pos++;
297 
298 	} else {
299 		/*
300 		 * The last data was pushed to ICRXTX on _PREV_ empty irq.
301 		 * It is on _SHIFT_ register, and will sent to I2C bus.
302 		 *
303 		 *		  *
304 		 * [ICRXTX] -> [SHIFT] -> [I2C bus]
305 		 */
306 
307 		if (priv->flags & ID_LAST_MSG)
308 			/*
309 			 * If current msg is the _LAST_ msg,
310 			 * prepare stop condition here.
311 			 * ID_DONE will be set on STOP irq.
312 			 */
313 			rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
314 		else
315 			/*
316 			 * If current msg is _NOT_ last msg,
317 			 * it doesn't call stop phase.
318 			 * thus, there is no STOP irq.
319 			 * return ID_DONE here.
320 			 */
321 			return ID_DONE;
322 	}
323 
324 	rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND);
325 
326 	return 0;
327 }
328 
329 static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
330 {
331 	struct i2c_msg *msg = priv->msg;
332 
333 	/*
334 	 * FIXME
335 	 * sometimes, unknown interrupt happened.
336 	 * Do nothing
337 	 */
338 	if (!(msr & MDR))
339 		return 0;
340 
341 	if (msr & MAT) {
342 		/*
343 		 * Address transfer phase finished,
344 		 * but, there is no data at this point.
345 		 * Do nothing.
346 		 */
347 	} else if (priv->pos < msg->len) {
348 		/*
349 		 * get received data
350 		 */
351 		msg->buf[priv->pos] = rcar_i2c_read(priv, ICRXTX);
352 		priv->pos++;
353 	}
354 
355 	/*
356 	 * If next received data is the _LAST_,
357 	 * go to STOP phase,
358 	 * otherwise, go to DATA phase.
359 	 */
360 	if (priv->pos + 1 >= msg->len)
361 		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
362 	else
363 		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
364 
365 	rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV);
366 
367 	return 0;
368 }
369 
370 static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv)
371 {
372 	u32 ssr_raw, ssr_filtered;
373 	u8 value;
374 
375 	ssr_raw = rcar_i2c_read(priv, ICSSR) & 0xff;
376 	ssr_filtered = ssr_raw & rcar_i2c_read(priv, ICSIER);
377 
378 	if (!ssr_filtered)
379 		return false;
380 
381 	/* address detected */
382 	if (ssr_filtered & SAR) {
383 		/* read or write request */
384 		if (ssr_raw & STM) {
385 			i2c_slave_event(priv->slave, I2C_SLAVE_READ_REQUESTED, &value);
386 			rcar_i2c_write(priv, ICRXTX, value);
387 			rcar_i2c_write(priv, ICSIER, SDE | SSR | SAR);
388 		} else {
389 			i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
390 			rcar_i2c_read(priv, ICRXTX);	/* dummy read */
391 			rcar_i2c_write(priv, ICSIER, SDR | SSR | SAR);
392 		}
393 
394 		rcar_i2c_write(priv, ICSSR, ~SAR & 0xff);
395 	}
396 
397 	/* master sent stop */
398 	if (ssr_filtered & SSR) {
399 		i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value);
400 		rcar_i2c_write(priv, ICSIER, SAR | SSR);
401 		rcar_i2c_write(priv, ICSSR, ~SSR & 0xff);
402 	}
403 
404 	/* master wants to write to us */
405 	if (ssr_filtered & SDR) {
406 		int ret;
407 
408 		value = rcar_i2c_read(priv, ICRXTX);
409 		ret = i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_RECEIVED, &value);
410 		/* Send NACK in case of error */
411 		rcar_i2c_write(priv, ICSCR, SIE | SDBS | (ret < 0 ? FNA : 0));
412 		rcar_i2c_write(priv, ICSSR, ~SDR & 0xff);
413 	}
414 
415 	/* master wants to read from us */
416 	if (ssr_filtered & SDE) {
417 		i2c_slave_event(priv->slave, I2C_SLAVE_READ_PROCESSED, &value);
418 		rcar_i2c_write(priv, ICRXTX, value);
419 		rcar_i2c_write(priv, ICSSR, ~SDE & 0xff);
420 	}
421 
422 	return true;
423 }
424 
425 static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
426 {
427 	struct rcar_i2c_priv *priv = ptr;
428 	irqreturn_t result = IRQ_HANDLED;
429 	u32 msr;
430 
431 	/*-------------- spin lock -----------------*/
432 	spin_lock(&priv->lock);
433 
434 	if (rcar_i2c_slave_irq(priv))
435 		goto exit;
436 
437 	msr = rcar_i2c_read(priv, ICMSR);
438 
439 	/* Only handle interrupts that are currently enabled */
440 	msr &= rcar_i2c_read(priv, ICMIER);
441 	if (!msr) {
442 		result = IRQ_NONE;
443 		goto exit;
444 	}
445 
446 	/* Arbitration lost */
447 	if (msr & MAL) {
448 		rcar_i2c_flags_set(priv, (ID_DONE | ID_ARBLOST));
449 		goto out;
450 	}
451 
452 	/* Nack */
453 	if (msr & MNR) {
454 		/* go to stop phase */
455 		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
456 		rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
457 		rcar_i2c_flags_set(priv, ID_NACK);
458 		goto out;
459 	}
460 
461 	/* Stop */
462 	if (msr & MST) {
463 		rcar_i2c_flags_set(priv, ID_DONE);
464 		goto out;
465 	}
466 
467 	if (rcar_i2c_is_recv(priv))
468 		rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr));
469 	else
470 		rcar_i2c_flags_set(priv, rcar_i2c_irq_send(priv, msr));
471 
472 out:
473 	if (rcar_i2c_flags_has(priv, ID_DONE)) {
474 		rcar_i2c_write(priv, ICMIER, 0);
475 		rcar_i2c_write(priv, ICMSR, 0);
476 		wake_up(&priv->wait);
477 	}
478 
479 exit:
480 	spin_unlock(&priv->lock);
481 	/*-------------- spin unlock -----------------*/
482 
483 	return result;
484 }
485 
486 static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
487 				struct i2c_msg *msgs,
488 				int num)
489 {
490 	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
491 	struct device *dev = rcar_i2c_priv_to_dev(priv);
492 	unsigned long flags;
493 	int i, ret, timeout;
494 
495 	pm_runtime_get_sync(dev);
496 
497 	/*-------------- spin lock -----------------*/
498 	spin_lock_irqsave(&priv->lock, flags);
499 
500 	rcar_i2c_init(priv);
501 	/* start clock */
502 	rcar_i2c_write(priv, ICCCR, priv->icccr);
503 
504 	spin_unlock_irqrestore(&priv->lock, flags);
505 	/*-------------- spin unlock -----------------*/
506 
507 	ret = rcar_i2c_bus_barrier(priv);
508 	if (ret < 0)
509 		goto out;
510 
511 	for (i = 0; i < num; i++) {
512 		/* This HW can't send STOP after address phase */
513 		if (msgs[i].len == 0) {
514 			ret = -EOPNOTSUPP;
515 			break;
516 		}
517 
518 		/*-------------- spin lock -----------------*/
519 		spin_lock_irqsave(&priv->lock, flags);
520 
521 		/* init each data */
522 		priv->msg	= &msgs[i];
523 		priv->pos	= 0;
524 		priv->flags	= 0;
525 		if (i == num - 1)
526 			rcar_i2c_flags_set(priv, ID_LAST_MSG);
527 
528 		rcar_i2c_prepare_msg(priv);
529 
530 		spin_unlock_irqrestore(&priv->lock, flags);
531 		/*-------------- spin unlock -----------------*/
532 
533 		timeout = wait_event_timeout(priv->wait,
534 					     rcar_i2c_flags_has(priv, ID_DONE),
535 					     5 * HZ);
536 		if (!timeout) {
537 			ret = -ETIMEDOUT;
538 			break;
539 		}
540 
541 		if (rcar_i2c_flags_has(priv, ID_NACK)) {
542 			ret = -ENXIO;
543 			break;
544 		}
545 
546 		if (rcar_i2c_flags_has(priv, ID_ARBLOST)) {
547 			ret = -EAGAIN;
548 			break;
549 		}
550 
551 		if (rcar_i2c_flags_has(priv, ID_IOERROR)) {
552 			ret = -EIO;
553 			break;
554 		}
555 
556 		ret = i + 1; /* The number of transfer */
557 	}
558 out:
559 	pm_runtime_put(dev);
560 
561 	if (ret < 0 && ret != -ENXIO)
562 		dev_err(dev, "error %d : %x\n", ret, priv->flags);
563 
564 	return ret;
565 }
566 
567 static int rcar_reg_slave(struct i2c_client *slave)
568 {
569 	struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
570 
571 	if (priv->slave)
572 		return -EBUSY;
573 
574 	if (slave->flags & I2C_CLIENT_TEN)
575 		return -EAFNOSUPPORT;
576 
577 	pm_runtime_forbid(rcar_i2c_priv_to_dev(priv));
578 
579 	priv->slave = slave;
580 	rcar_i2c_write(priv, ICSAR, slave->addr);
581 	rcar_i2c_write(priv, ICSSR, 0);
582 	rcar_i2c_write(priv, ICSIER, SAR | SSR);
583 	rcar_i2c_write(priv, ICSCR, SIE | SDBS);
584 
585 	return 0;
586 }
587 
588 static int rcar_unreg_slave(struct i2c_client *slave)
589 {
590 	struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
591 
592 	WARN_ON(!priv->slave);
593 
594 	rcar_i2c_write(priv, ICSIER, 0);
595 	rcar_i2c_write(priv, ICSCR, 0);
596 
597 	priv->slave = NULL;
598 
599 	pm_runtime_allow(rcar_i2c_priv_to_dev(priv));
600 
601 	return 0;
602 }
603 
604 static u32 rcar_i2c_func(struct i2c_adapter *adap)
605 {
606 	/* This HW can't do SMBUS_QUICK and NOSTART */
607 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
608 }
609 
610 static const struct i2c_algorithm rcar_i2c_algo = {
611 	.master_xfer	= rcar_i2c_master_xfer,
612 	.functionality	= rcar_i2c_func,
613 	.reg_slave	= rcar_reg_slave,
614 	.unreg_slave	= rcar_unreg_slave,
615 };
616 
617 static const struct of_device_id rcar_i2c_dt_ids[] = {
618 	{ .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 },
619 	{ .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 },
620 	{ .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
621 	{ .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 },
622 	{ .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 },
623 	{ .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 },
624 	{ .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 },
625 	{ .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
626 	{},
627 };
628 MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids);
629 
630 static int rcar_i2c_probe(struct platform_device *pdev)
631 {
632 	struct i2c_rcar_platform_data *pdata = dev_get_platdata(&pdev->dev);
633 	struct rcar_i2c_priv *priv;
634 	struct i2c_adapter *adap;
635 	struct resource *res;
636 	struct device *dev = &pdev->dev;
637 	u32 bus_speed;
638 	int irq, ret;
639 
640 	priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);
641 	if (!priv)
642 		return -ENOMEM;
643 
644 	priv->clk = devm_clk_get(dev, NULL);
645 	if (IS_ERR(priv->clk)) {
646 		dev_err(dev, "cannot get clock\n");
647 		return PTR_ERR(priv->clk);
648 	}
649 
650 	bus_speed = 100000; /* default 100 kHz */
651 	ret = of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed);
652 	if (ret < 0 && pdata && pdata->bus_speed)
653 		bus_speed = pdata->bus_speed;
654 
655 	if (pdev->dev.of_node)
656 		priv->devtype = (long)of_match_device(rcar_i2c_dt_ids,
657 						      dev)->data;
658 	else
659 		priv->devtype = platform_get_device_id(pdev)->driver_data;
660 
661 	ret = rcar_i2c_clock_calculate(priv, bus_speed, dev);
662 	if (ret < 0)
663 		return ret;
664 
665 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
666 	priv->io = devm_ioremap_resource(dev, res);
667 	if (IS_ERR(priv->io))
668 		return PTR_ERR(priv->io);
669 
670 	irq = platform_get_irq(pdev, 0);
671 	init_waitqueue_head(&priv->wait);
672 	spin_lock_init(&priv->lock);
673 
674 	adap = &priv->adap;
675 	adap->nr = pdev->id;
676 	adap->algo = &rcar_i2c_algo;
677 	adap->class = I2C_CLASS_DEPRECATED;
678 	adap->retries = 3;
679 	adap->dev.parent = dev;
680 	adap->dev.of_node = dev->of_node;
681 	i2c_set_adapdata(adap, priv);
682 	strlcpy(adap->name, pdev->name, sizeof(adap->name));
683 
684 	ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0,
685 			       dev_name(dev), priv);
686 	if (ret < 0) {
687 		dev_err(dev, "cannot get irq %d\n", irq);
688 		return ret;
689 	}
690 
691 	ret = i2c_add_numbered_adapter(adap);
692 	if (ret < 0) {
693 		dev_err(dev, "reg adap failed: %d\n", ret);
694 		return ret;
695 	}
696 
697 	pm_runtime_enable(dev);
698 	platform_set_drvdata(pdev, priv);
699 
700 	dev_info(dev, "probed\n");
701 
702 	return 0;
703 }
704 
705 static int rcar_i2c_remove(struct platform_device *pdev)
706 {
707 	struct rcar_i2c_priv *priv = platform_get_drvdata(pdev);
708 	struct device *dev = &pdev->dev;
709 
710 	i2c_del_adapter(&priv->adap);
711 	pm_runtime_disable(dev);
712 
713 	return 0;
714 }
715 
716 static struct platform_device_id rcar_i2c_id_table[] = {
717 	{ "i2c-rcar",		I2C_RCAR_GEN1 },
718 	{ "i2c-rcar_gen1",	I2C_RCAR_GEN1 },
719 	{ "i2c-rcar_gen2",	I2C_RCAR_GEN2 },
720 	{},
721 };
722 MODULE_DEVICE_TABLE(platform, rcar_i2c_id_table);
723 
724 static struct platform_driver rcar_i2c_driver = {
725 	.driver	= {
726 		.name	= "i2c-rcar",
727 		.of_match_table = rcar_i2c_dt_ids,
728 	},
729 	.probe		= rcar_i2c_probe,
730 	.remove		= rcar_i2c_remove,
731 	.id_table	= rcar_i2c_id_table,
732 };
733 
734 module_platform_driver(rcar_i2c_driver);
735 
736 MODULE_LICENSE("GPL v2");
737 MODULE_DESCRIPTION("Renesas R-Car I2C bus driver");
738 MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
739