xref: /openbmc/linux/drivers/i2c/busses/i2c-rcar.c (revision a06c488d)
1 /*
2  * Driver for the Renesas RCar I2C unit
3  *
4  * Copyright (C) 2014-15 Wolfram Sang <wsa@sang-engineering.com>
5  * Copyright (C) 2011-2015 Renesas Electronics Corporation
6  *
7  * Copyright (C) 2012-14 Renesas Solutions Corp.
8  * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
9  *
10  * This file is based on the drivers/i2c/busses/i2c-sh7760.c
11  * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; version 2 of the License.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  */
22 #include <linux/clk.h>
23 #include <linux/delay.h>
24 #include <linux/err.h>
25 #include <linux/interrupt.h>
26 #include <linux/io.h>
27 #include <linux/i2c.h>
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/of_device.h>
31 #include <linux/platform_device.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/slab.h>
34 
35 /* register offsets */
36 #define ICSCR	0x00	/* slave ctrl */
37 #define ICMCR	0x04	/* master ctrl */
38 #define ICSSR	0x08	/* slave status */
39 #define ICMSR	0x0C	/* master status */
40 #define ICSIER	0x10	/* slave irq enable */
41 #define ICMIER	0x14	/* master irq enable */
42 #define ICCCR	0x18	/* clock dividers */
43 #define ICSAR	0x1C	/* slave address */
44 #define ICMAR	0x20	/* master address */
45 #define ICRXTX	0x24	/* data port */
46 
47 /* ICSCR */
48 #define SDBS	(1 << 3)	/* slave data buffer select */
49 #define SIE	(1 << 2)	/* slave interface enable */
50 #define GCAE	(1 << 1)	/* general call address enable */
51 #define FNA	(1 << 0)	/* forced non acknowledgment */
52 
53 /* ICMCR */
54 #define MDBS	(1 << 7)	/* non-fifo mode switch */
55 #define FSCL	(1 << 6)	/* override SCL pin */
56 #define FSDA	(1 << 5)	/* override SDA pin */
57 #define OBPC	(1 << 4)	/* override pins */
58 #define MIE	(1 << 3)	/* master if enable */
59 #define TSBE	(1 << 2)
60 #define FSB	(1 << 1)	/* force stop bit */
61 #define ESG	(1 << 0)	/* en startbit gen */
62 
63 /* ICSSR (also for ICSIER) */
64 #define GCAR	(1 << 6)	/* general call received */
65 #define STM	(1 << 5)	/* slave transmit mode */
66 #define SSR	(1 << 4)	/* stop received */
67 #define SDE	(1 << 3)	/* slave data empty */
68 #define SDT	(1 << 2)	/* slave data transmitted */
69 #define SDR	(1 << 1)	/* slave data received */
70 #define SAR	(1 << 0)	/* slave addr received */
71 
72 /* ICMSR (also for ICMIE) */
73 #define MNR	(1 << 6)	/* nack received */
74 #define MAL	(1 << 5)	/* arbitration lost */
75 #define MST	(1 << 4)	/* sent a stop */
76 #define MDE	(1 << 3)
77 #define MDT	(1 << 2)
78 #define MDR	(1 << 1)
79 #define MAT	(1 << 0)	/* slave addr xfer done */
80 
81 
82 #define RCAR_BUS_PHASE_START	(MDBS | MIE | ESG)
83 #define RCAR_BUS_PHASE_DATA	(MDBS | MIE)
84 #define RCAR_BUS_MASK_DATA	(~(ESG | FSB) & 0xFF)
85 #define RCAR_BUS_PHASE_STOP	(MDBS | MIE | FSB)
86 
87 #define RCAR_IRQ_SEND	(MNR | MAL | MST | MAT | MDE)
88 #define RCAR_IRQ_RECV	(MNR | MAL | MST | MAT | MDR)
89 #define RCAR_IRQ_STOP	(MST)
90 
91 #define RCAR_IRQ_ACK_SEND	(~(MAT | MDE) & 0xFF)
92 #define RCAR_IRQ_ACK_RECV	(~(MAT | MDR) & 0xFF)
93 
94 #define ID_LAST_MSG	(1 << 0)
95 #define ID_FIRST_MSG	(1 << 1)
96 #define ID_DONE		(1 << 2)
97 #define ID_ARBLOST	(1 << 3)
98 #define ID_NACK		(1 << 4)
99 /* persistent flags */
100 #define ID_P_PM_BLOCKED	(1 << 31)
101 #define ID_P_MASK	ID_P_PM_BLOCKED
102 
103 enum rcar_i2c_type {
104 	I2C_RCAR_GEN1,
105 	I2C_RCAR_GEN2,
106 	I2C_RCAR_GEN3,
107 };
108 
109 struct rcar_i2c_priv {
110 	void __iomem *io;
111 	struct i2c_adapter adap;
112 	struct i2c_msg *msg;
113 	int msgs_left;
114 	struct clk *clk;
115 
116 	wait_queue_head_t wait;
117 
118 	int pos;
119 	u32 icccr;
120 	u32 flags;
121 	enum rcar_i2c_type devtype;
122 	struct i2c_client *slave;
123 };
124 
125 #define rcar_i2c_priv_to_dev(p)		((p)->adap.dev.parent)
126 #define rcar_i2c_is_recv(p)		((p)->msg->flags & I2C_M_RD)
127 
128 #define LOOP_TIMEOUT	1024
129 
130 
131 static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
132 {
133 	writel(val, priv->io + reg);
134 }
135 
136 static u32 rcar_i2c_read(struct rcar_i2c_priv *priv, int reg)
137 {
138 	return readl(priv->io + reg);
139 }
140 
141 static void rcar_i2c_init(struct rcar_i2c_priv *priv)
142 {
143 	/* reset master mode */
144 	rcar_i2c_write(priv, ICMIER, 0);
145 	rcar_i2c_write(priv, ICMCR, MDBS);
146 	rcar_i2c_write(priv, ICMSR, 0);
147 	/* start clock */
148 	rcar_i2c_write(priv, ICCCR, priv->icccr);
149 }
150 
151 static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
152 {
153 	int i;
154 
155 	for (i = 0; i < LOOP_TIMEOUT; i++) {
156 		/* make sure that bus is not busy */
157 		if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
158 			return 0;
159 		udelay(1);
160 	}
161 
162 	return -EBUSY;
163 }
164 
165 static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timings *t)
166 {
167 	u32 scgd, cdf, round, ick, sum, scl, cdf_width;
168 	unsigned long rate;
169 	struct device *dev = rcar_i2c_priv_to_dev(priv);
170 
171 	/* Fall back to previously used values if not supplied */
172 	t->bus_freq_hz = t->bus_freq_hz ?: 100000;
173 	t->scl_fall_ns = t->scl_fall_ns ?: 35;
174 	t->scl_rise_ns = t->scl_rise_ns ?: 200;
175 	t->scl_int_delay_ns = t->scl_int_delay_ns ?: 50;
176 
177 	switch (priv->devtype) {
178 	case I2C_RCAR_GEN1:
179 		cdf_width = 2;
180 		break;
181 	case I2C_RCAR_GEN2:
182 	case I2C_RCAR_GEN3:
183 		cdf_width = 3;
184 		break;
185 	default:
186 		dev_err(dev, "device type error\n");
187 		return -EIO;
188 	}
189 
190 	/*
191 	 * calculate SCL clock
192 	 * see
193 	 *	ICCCR
194 	 *
195 	 * ick	= clkp / (1 + CDF)
196 	 * SCL	= ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
197 	 *
198 	 * ick  : I2C internal clock < 20 MHz
199 	 * ticf : I2C SCL falling time
200 	 * tr   : I2C SCL rising  time
201 	 * intd : LSI internal delay
202 	 * clkp : peripheral_clk
203 	 * F[]  : integer up-valuation
204 	 */
205 	rate = clk_get_rate(priv->clk);
206 	cdf = rate / 20000000;
207 	if (cdf >= 1U << cdf_width) {
208 		dev_err(dev, "Input clock %lu too high\n", rate);
209 		return -EIO;
210 	}
211 	ick = rate / (cdf + 1);
212 
213 	/*
214 	 * it is impossible to calculate large scale
215 	 * number on u32. separate it
216 	 *
217 	 * F[(ticf + tr + intd) * ick] with sum = (ticf + tr + intd)
218 	 *  = F[sum * ick / 1000000000]
219 	 *  = F[(ick / 1000000) * sum / 1000]
220 	 */
221 	sum = t->scl_fall_ns + t->scl_rise_ns + t->scl_int_delay_ns;
222 	round = (ick + 500000) / 1000000 * sum;
223 	round = (round + 500) / 1000;
224 
225 	/*
226 	 * SCL	= ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
227 	 *
228 	 * Calculation result (= SCL) should be less than
229 	 * bus_speed for hardware safety
230 	 *
231 	 * We could use something along the lines of
232 	 *	div = ick / (bus_speed + 1) + 1;
233 	 *	scgd = (div - 20 - round + 7) / 8;
234 	 *	scl = ick / (20 + (scgd * 8) + round);
235 	 * (not fully verified) but that would get pretty involved
236 	 */
237 	for (scgd = 0; scgd < 0x40; scgd++) {
238 		scl = ick / (20 + (scgd * 8) + round);
239 		if (scl <= t->bus_freq_hz)
240 			goto scgd_find;
241 	}
242 	dev_err(dev, "it is impossible to calculate best SCL\n");
243 	return -EIO;
244 
245 scgd_find:
246 	dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n",
247 		scl, t->bus_freq_hz, clk_get_rate(priv->clk), round, cdf, scgd);
248 
249 	/* keep icccr value */
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 	priv->pos = 0;
260 	if (priv->msgs_left == 1)
261 		priv->flags |= ID_LAST_MSG;
262 
263 	rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read);
264 	/*
265 	 * We don't have a testcase but the HW engineers say that the write order
266 	 * of ICMSR and ICMCR depends on whether we issue START or REP_START. Since
267 	 * it didn't cause a drawback for me, let's rather be safe than sorry.
268 	 */
269 	if (priv->flags & ID_FIRST_MSG) {
270 		rcar_i2c_write(priv, ICMSR, 0);
271 		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
272 	} else {
273 		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
274 		rcar_i2c_write(priv, ICMSR, 0);
275 	}
276 	rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
277 }
278 
279 static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv)
280 {
281 	priv->msg++;
282 	priv->msgs_left--;
283 	priv->flags &= ID_P_MASK;
284 	rcar_i2c_prepare_msg(priv);
285 }
286 
287 /*
288  *		interrupt functions
289  */
290 static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
291 {
292 	struct i2c_msg *msg = priv->msg;
293 
294 	/* FIXME: sometimes, unknown interrupt happened. Do nothing */
295 	if (!(msr & MDE))
296 		return;
297 
298 	if (priv->pos < msg->len) {
299 		/*
300 		 * Prepare next data to ICRXTX register.
301 		 * This data will go to _SHIFT_ register.
302 		 *
303 		 *    *
304 		 * [ICRXTX] -> [SHIFT] -> [I2C bus]
305 		 */
306 		rcar_i2c_write(priv, ICRXTX, msg->buf[priv->pos]);
307 		priv->pos++;
308 
309 	} else {
310 		/*
311 		 * The last data was pushed to ICRXTX on _PREV_ empty irq.
312 		 * It is on _SHIFT_ register, and will sent to I2C bus.
313 		 *
314 		 *		  *
315 		 * [ICRXTX] -> [SHIFT] -> [I2C bus]
316 		 */
317 
318 		if (priv->flags & ID_LAST_MSG) {
319 			/*
320 			 * If current msg is the _LAST_ msg,
321 			 * prepare stop condition here.
322 			 * ID_DONE will be set on STOP irq.
323 			 */
324 			rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
325 		} else {
326 			rcar_i2c_next_msg(priv);
327 			return;
328 		}
329 	}
330 
331 	rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND);
332 }
333 
334 static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
335 {
336 	struct i2c_msg *msg = priv->msg;
337 
338 	/* FIXME: sometimes, unknown interrupt happened. Do nothing */
339 	if (!(msr & MDR))
340 		return;
341 
342 	if (msr & MAT) {
343 		/* Address transfer phase finished, but no data at this point. */
344 	} else if (priv->pos < msg->len) {
345 		/* get received data */
346 		msg->buf[priv->pos] = rcar_i2c_read(priv, ICRXTX);
347 		priv->pos++;
348 	}
349 
350 	/*
351 	 * If next received data is the _LAST_, go to STOP phase. Might be
352 	 * overwritten by REP START when setting up a new msg. Not elegant
353 	 * but the only stable sequence for REP START I have found so far.
354 	 */
355 	if (priv->pos + 1 >= msg->len)
356 		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
357 
358 	if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG))
359 		rcar_i2c_next_msg(priv);
360 	else
361 		rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV);
362 }
363 
364 static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv)
365 {
366 	u32 ssr_raw, ssr_filtered;
367 	u8 value;
368 
369 	ssr_raw = rcar_i2c_read(priv, ICSSR) & 0xff;
370 	ssr_filtered = ssr_raw & rcar_i2c_read(priv, ICSIER);
371 
372 	if (!ssr_filtered)
373 		return false;
374 
375 	/* address detected */
376 	if (ssr_filtered & SAR) {
377 		/* read or write request */
378 		if (ssr_raw & STM) {
379 			i2c_slave_event(priv->slave, I2C_SLAVE_READ_REQUESTED, &value);
380 			rcar_i2c_write(priv, ICRXTX, value);
381 			rcar_i2c_write(priv, ICSIER, SDE | SSR | SAR);
382 		} else {
383 			i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
384 			rcar_i2c_read(priv, ICRXTX);	/* dummy read */
385 			rcar_i2c_write(priv, ICSIER, SDR | SSR | SAR);
386 		}
387 
388 		rcar_i2c_write(priv, ICSSR, ~SAR & 0xff);
389 	}
390 
391 	/* master sent stop */
392 	if (ssr_filtered & SSR) {
393 		i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value);
394 		rcar_i2c_write(priv, ICSIER, SAR | SSR);
395 		rcar_i2c_write(priv, ICSSR, ~SSR & 0xff);
396 	}
397 
398 	/* master wants to write to us */
399 	if (ssr_filtered & SDR) {
400 		int ret;
401 
402 		value = rcar_i2c_read(priv, ICRXTX);
403 		ret = i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_RECEIVED, &value);
404 		/* Send NACK in case of error */
405 		rcar_i2c_write(priv, ICSCR, SIE | SDBS | (ret < 0 ? FNA : 0));
406 		rcar_i2c_write(priv, ICSSR, ~SDR & 0xff);
407 	}
408 
409 	/* master wants to read from us */
410 	if (ssr_filtered & SDE) {
411 		i2c_slave_event(priv->slave, I2C_SLAVE_READ_PROCESSED, &value);
412 		rcar_i2c_write(priv, ICRXTX, value);
413 		rcar_i2c_write(priv, ICSSR, ~SDE & 0xff);
414 	}
415 
416 	return true;
417 }
418 
419 static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
420 {
421 	struct rcar_i2c_priv *priv = ptr;
422 	u32 msr, val;
423 
424 	/* Clear START or STOP as soon as we can */
425 	val = rcar_i2c_read(priv, ICMCR);
426 	rcar_i2c_write(priv, ICMCR, val & RCAR_BUS_MASK_DATA);
427 
428 	msr = rcar_i2c_read(priv, ICMSR);
429 
430 	/* Only handle interrupts that are currently enabled */
431 	msr &= rcar_i2c_read(priv, ICMIER);
432 	if (!msr) {
433 		if (rcar_i2c_slave_irq(priv))
434 			return IRQ_HANDLED;
435 
436 		return IRQ_NONE;
437 	}
438 
439 	/* Arbitration lost */
440 	if (msr & MAL) {
441 		priv->flags |= ID_DONE | ID_ARBLOST;
442 		goto out;
443 	}
444 
445 	/* Nack */
446 	if (msr & MNR) {
447 		/* HW automatically sends STOP after received NACK */
448 		rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
449 		priv->flags |= ID_NACK;
450 		goto out;
451 	}
452 
453 	/* Stop */
454 	if (msr & MST) {
455 		priv->msgs_left--; /* The last message also made it */
456 		priv->flags |= ID_DONE;
457 		goto out;
458 	}
459 
460 	if (rcar_i2c_is_recv(priv))
461 		rcar_i2c_irq_recv(priv, msr);
462 	else
463 		rcar_i2c_irq_send(priv, msr);
464 
465 out:
466 	if (priv->flags & ID_DONE) {
467 		rcar_i2c_write(priv, ICMIER, 0);
468 		rcar_i2c_write(priv, ICMSR, 0);
469 		wake_up(&priv->wait);
470 	}
471 
472 	return IRQ_HANDLED;
473 }
474 
475 static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
476 				struct i2c_msg *msgs,
477 				int num)
478 {
479 	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
480 	struct device *dev = rcar_i2c_priv_to_dev(priv);
481 	int i, ret;
482 	long time_left;
483 
484 	pm_runtime_get_sync(dev);
485 
486 	ret = rcar_i2c_bus_barrier(priv);
487 	if (ret < 0)
488 		goto out;
489 
490 	for (i = 0; i < num; i++) {
491 		/* This HW can't send STOP after address phase */
492 		if (msgs[i].len == 0) {
493 			ret = -EOPNOTSUPP;
494 			goto out;
495 		}
496 	}
497 
498 	/* init first message */
499 	priv->msg = msgs;
500 	priv->msgs_left = num;
501 	priv->flags = (priv->flags & ID_P_MASK) | ID_FIRST_MSG;
502 	rcar_i2c_prepare_msg(priv);
503 
504 	time_left = wait_event_timeout(priv->wait, priv->flags & ID_DONE,
505 				     num * adap->timeout);
506 	if (!time_left) {
507 		rcar_i2c_init(priv);
508 		ret = -ETIMEDOUT;
509 	} else if (priv->flags & ID_NACK) {
510 		ret = -ENXIO;
511 	} else if (priv->flags & ID_ARBLOST) {
512 		ret = -EAGAIN;
513 	} else {
514 		ret = num - priv->msgs_left; /* The number of transfer */
515 	}
516 out:
517 	pm_runtime_put(dev);
518 
519 	if (ret < 0 && ret != -ENXIO)
520 		dev_err(dev, "error %d : %x\n", ret, priv->flags);
521 
522 	return ret;
523 }
524 
525 static int rcar_reg_slave(struct i2c_client *slave)
526 {
527 	struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
528 
529 	if (priv->slave)
530 		return -EBUSY;
531 
532 	if (slave->flags & I2C_CLIENT_TEN)
533 		return -EAFNOSUPPORT;
534 
535 	pm_runtime_get_sync(rcar_i2c_priv_to_dev(priv));
536 
537 	priv->slave = slave;
538 	rcar_i2c_write(priv, ICSAR, slave->addr);
539 	rcar_i2c_write(priv, ICSSR, 0);
540 	rcar_i2c_write(priv, ICSIER, SAR | SSR);
541 	rcar_i2c_write(priv, ICSCR, SIE | SDBS);
542 
543 	return 0;
544 }
545 
546 static int rcar_unreg_slave(struct i2c_client *slave)
547 {
548 	struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
549 
550 	WARN_ON(!priv->slave);
551 
552 	rcar_i2c_write(priv, ICSIER, 0);
553 	rcar_i2c_write(priv, ICSCR, 0);
554 
555 	priv->slave = NULL;
556 
557 	pm_runtime_put(rcar_i2c_priv_to_dev(priv));
558 
559 	return 0;
560 }
561 
562 static u32 rcar_i2c_func(struct i2c_adapter *adap)
563 {
564 	/* This HW can't do SMBUS_QUICK and NOSTART */
565 	return I2C_FUNC_I2C | I2C_FUNC_SLAVE |
566 		(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
567 }
568 
569 static const struct i2c_algorithm rcar_i2c_algo = {
570 	.master_xfer	= rcar_i2c_master_xfer,
571 	.functionality	= rcar_i2c_func,
572 	.reg_slave	= rcar_reg_slave,
573 	.unreg_slave	= rcar_unreg_slave,
574 };
575 
576 static const struct of_device_id rcar_i2c_dt_ids[] = {
577 	{ .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 },
578 	{ .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 },
579 	{ .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
580 	{ .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 },
581 	{ .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 },
582 	{ .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 },
583 	{ .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 },
584 	{ .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
585 	{ .compatible = "renesas,i2c-r8a7795", .data = (void *)I2C_RCAR_GEN3 },
586 	{},
587 };
588 MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids);
589 
590 static int rcar_i2c_probe(struct platform_device *pdev)
591 {
592 	struct rcar_i2c_priv *priv;
593 	struct i2c_adapter *adap;
594 	struct resource *res;
595 	struct device *dev = &pdev->dev;
596 	struct i2c_timings i2c_t;
597 	int irq, ret;
598 
599 	priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);
600 	if (!priv)
601 		return -ENOMEM;
602 
603 	priv->clk = devm_clk_get(dev, NULL);
604 	if (IS_ERR(priv->clk)) {
605 		dev_err(dev, "cannot get clock\n");
606 		return PTR_ERR(priv->clk);
607 	}
608 
609 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
610 	priv->io = devm_ioremap_resource(dev, res);
611 	if (IS_ERR(priv->io))
612 		return PTR_ERR(priv->io);
613 
614 	priv->devtype = (enum rcar_i2c_type)of_match_device(rcar_i2c_dt_ids, dev)->data;
615 	init_waitqueue_head(&priv->wait);
616 
617 	adap = &priv->adap;
618 	adap->nr = pdev->id;
619 	adap->algo = &rcar_i2c_algo;
620 	adap->class = I2C_CLASS_DEPRECATED;
621 	adap->retries = 3;
622 	adap->dev.parent = dev;
623 	adap->dev.of_node = dev->of_node;
624 	i2c_set_adapdata(adap, priv);
625 	strlcpy(adap->name, pdev->name, sizeof(adap->name));
626 
627 	i2c_parse_fw_timings(dev, &i2c_t, false);
628 
629 	pm_runtime_enable(dev);
630 	pm_runtime_get_sync(dev);
631 	ret = rcar_i2c_clock_calculate(priv, &i2c_t);
632 	if (ret < 0)
633 		goto out_pm_put;
634 
635 	rcar_i2c_init(priv);
636 
637 	/* Don't suspend when multi-master to keep arbitration working */
638 	if (of_property_read_bool(dev->of_node, "multi-master"))
639 		priv->flags |= ID_P_PM_BLOCKED;
640 	else
641 		pm_runtime_put(dev);
642 
643 
644 	irq = platform_get_irq(pdev, 0);
645 	ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0, dev_name(dev), priv);
646 	if (ret < 0) {
647 		dev_err(dev, "cannot get irq %d\n", irq);
648 		goto out_pm_disable;
649 	}
650 
651 	platform_set_drvdata(pdev, priv);
652 
653 	ret = i2c_add_numbered_adapter(adap);
654 	if (ret < 0) {
655 		dev_err(dev, "reg adap failed: %d\n", ret);
656 		goto out_pm_disable;
657 	}
658 
659 	dev_info(dev, "probed\n");
660 
661 	return 0;
662 
663  out_pm_put:
664 	pm_runtime_put(dev);
665  out_pm_disable:
666 	pm_runtime_disable(dev);
667 	return ret;
668 }
669 
670 static int rcar_i2c_remove(struct platform_device *pdev)
671 {
672 	struct rcar_i2c_priv *priv = platform_get_drvdata(pdev);
673 	struct device *dev = &pdev->dev;
674 
675 	i2c_del_adapter(&priv->adap);
676 	if (priv->flags & ID_P_PM_BLOCKED)
677 		pm_runtime_put(dev);
678 	pm_runtime_disable(dev);
679 
680 	return 0;
681 }
682 
683 static struct platform_driver rcar_i2c_driver = {
684 	.driver	= {
685 		.name	= "i2c-rcar",
686 		.of_match_table = rcar_i2c_dt_ids,
687 	},
688 	.probe		= rcar_i2c_probe,
689 	.remove		= rcar_i2c_remove,
690 };
691 
692 module_platform_driver(rcar_i2c_driver);
693 
694 MODULE_LICENSE("GPL v2");
695 MODULE_DESCRIPTION("Renesas R-Car I2C bus driver");
696 MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
697