1 /*
2  * This is i.MX low power i2c controller driver.
3  *
4  * Copyright 2016 Freescale Semiconductor, Inc.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  */
17 
18 #include <linux/clk.h>
19 #include <linux/completion.h>
20 #include <linux/delay.h>
21 #include <linux/err.h>
22 #include <linux/errno.h>
23 #include <linux/i2c.h>
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
26 #include <linux/io.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/of.h>
30 #include <linux/of_device.h>
31 #include <linux/pinctrl/consumer.h>
32 #include <linux/platform_device.h>
33 #include <linux/pm_runtime.h>
34 #include <linux/sched.h>
35 #include <linux/slab.h>
36 
37 #define DRIVER_NAME "imx-lpi2c"
38 
39 #define LPI2C_PARAM	0x04	/* i2c RX/TX FIFO size */
40 #define LPI2C_MCR	0x10	/* i2c contrl register */
41 #define LPI2C_MSR	0x14	/* i2c status register */
42 #define LPI2C_MIER	0x18	/* i2c interrupt enable */
43 #define LPI2C_MCFGR0	0x20	/* i2c master configuration */
44 #define LPI2C_MCFGR1	0x24	/* i2c master configuration */
45 #define LPI2C_MCFGR2	0x28	/* i2c master configuration */
46 #define LPI2C_MCFGR3	0x2C	/* i2c master configuration */
47 #define LPI2C_MCCR0	0x48	/* i2c master clk configuration */
48 #define LPI2C_MCCR1	0x50	/* i2c master clk configuration */
49 #define LPI2C_MFCR	0x58	/* i2c master FIFO control */
50 #define LPI2C_MFSR	0x5C	/* i2c master FIFO status */
51 #define LPI2C_MTDR	0x60	/* i2c master TX data register */
52 #define LPI2C_MRDR	0x70	/* i2c master RX data register */
53 
54 /* i2c command */
55 #define TRAN_DATA	0X00
56 #define RECV_DATA	0X01
57 #define GEN_STOP	0X02
58 #define RECV_DISCARD	0X03
59 #define GEN_START	0X04
60 #define START_NACK	0X05
61 #define START_HIGH	0X06
62 #define START_HIGH_NACK	0X07
63 
64 #define MCR_MEN		BIT(0)
65 #define MCR_RST		BIT(1)
66 #define MCR_DOZEN	BIT(2)
67 #define MCR_DBGEN	BIT(3)
68 #define MCR_RTF		BIT(8)
69 #define MCR_RRF		BIT(9)
70 #define MSR_TDF		BIT(0)
71 #define MSR_RDF		BIT(1)
72 #define MSR_SDF		BIT(9)
73 #define MSR_NDF		BIT(10)
74 #define MSR_ALF		BIT(11)
75 #define MSR_MBF		BIT(24)
76 #define MSR_BBF		BIT(25)
77 #define MIER_TDIE	BIT(0)
78 #define MIER_RDIE	BIT(1)
79 #define MIER_SDIE	BIT(9)
80 #define MIER_NDIE	BIT(10)
81 #define MCFGR1_AUTOSTOP	BIT(8)
82 #define MCFGR1_IGNACK	BIT(9)
83 #define MRDR_RXEMPTY	BIT(14)
84 
85 #define I2C_CLK_RATIO	2
86 #define CHUNK_DATA	256
87 
88 #define LPI2C_DEFAULT_RATE	100000
89 #define STARDARD_MAX_BITRATE	400000
90 #define FAST_MAX_BITRATE	1000000
91 #define FAST_PLUS_MAX_BITRATE	3400000
92 #define HIGHSPEED_MAX_BITRATE	5000000
93 
94 #define I2C_PM_TIMEOUT		10 /* ms */
95 
96 enum lpi2c_imx_mode {
97 	STANDARD,	/* 100+Kbps */
98 	FAST,		/* 400+Kbps */
99 	FAST_PLUS,	/* 1.0+Mbps */
100 	HS,		/* 3.4+Mbps */
101 	ULTRA_FAST,	/* 5.0+Mbps */
102 };
103 
104 enum lpi2c_imx_pincfg {
105 	TWO_PIN_OD,
106 	TWO_PIN_OO,
107 	TWO_PIN_PP,
108 	FOUR_PIN_PP,
109 };
110 
111 struct lpi2c_imx_struct {
112 	struct i2c_adapter	adapter;
113 	struct clk		*clk;
114 	void __iomem		*base;
115 	__u8			*rx_buf;
116 	__u8			*tx_buf;
117 	struct completion	complete;
118 	unsigned int		msglen;
119 	unsigned int		delivered;
120 	unsigned int		block_data;
121 	unsigned int		bitrate;
122 	unsigned int		txfifosize;
123 	unsigned int		rxfifosize;
124 	enum lpi2c_imx_mode	mode;
125 };
126 
127 static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx,
128 			      unsigned int enable)
129 {
130 	writel(enable, lpi2c_imx->base + LPI2C_MIER);
131 }
132 
133 static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct *lpi2c_imx)
134 {
135 	unsigned long orig_jiffies = jiffies;
136 	unsigned int temp;
137 
138 	while (1) {
139 		temp = readl(lpi2c_imx->base + LPI2C_MSR);
140 
141 		/* check for arbitration lost, clear if set */
142 		if (temp & MSR_ALF) {
143 			writel(temp, lpi2c_imx->base + LPI2C_MSR);
144 			return -EAGAIN;
145 		}
146 
147 		if (temp & (MSR_BBF | MSR_MBF))
148 			break;
149 
150 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
151 			dev_dbg(&lpi2c_imx->adapter.dev, "bus not work\n");
152 			return -ETIMEDOUT;
153 		}
154 		schedule();
155 	}
156 
157 	return 0;
158 }
159 
160 static void lpi2c_imx_set_mode(struct lpi2c_imx_struct *lpi2c_imx)
161 {
162 	unsigned int bitrate = lpi2c_imx->bitrate;
163 	enum lpi2c_imx_mode mode;
164 
165 	if (bitrate < STARDARD_MAX_BITRATE)
166 		mode = STANDARD;
167 	else if (bitrate < FAST_MAX_BITRATE)
168 		mode = FAST;
169 	else if (bitrate < FAST_PLUS_MAX_BITRATE)
170 		mode = FAST_PLUS;
171 	else if (bitrate < HIGHSPEED_MAX_BITRATE)
172 		mode = HS;
173 	else
174 		mode = ULTRA_FAST;
175 
176 	lpi2c_imx->mode = mode;
177 }
178 
179 static int lpi2c_imx_start(struct lpi2c_imx_struct *lpi2c_imx,
180 			   struct i2c_msg *msgs)
181 {
182 	unsigned int temp;
183 	u8 read;
184 
185 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
186 	temp |= MCR_RRF | MCR_RTF;
187 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
188 	writel(0x7f00, lpi2c_imx->base + LPI2C_MSR);
189 
190 	read = msgs->flags & I2C_M_RD;
191 	temp = (msgs->addr << 1 | read) | (GEN_START << 8);
192 	writel(temp, lpi2c_imx->base + LPI2C_MTDR);
193 
194 	return lpi2c_imx_bus_busy(lpi2c_imx);
195 }
196 
197 static void lpi2c_imx_stop(struct lpi2c_imx_struct *lpi2c_imx)
198 {
199 	unsigned long orig_jiffies = jiffies;
200 	unsigned int temp;
201 
202 	writel(GEN_STOP << 8, lpi2c_imx->base + LPI2C_MTDR);
203 
204 	do {
205 		temp = readl(lpi2c_imx->base + LPI2C_MSR);
206 		if (temp & MSR_SDF)
207 			break;
208 
209 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
210 			dev_dbg(&lpi2c_imx->adapter.dev, "stop timeout\n");
211 			break;
212 		}
213 		schedule();
214 
215 	} while (1);
216 }
217 
218 /* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 */
219 static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx)
220 {
221 	u8 prescale, filt, sethold, clkhi, clklo, datavd;
222 	unsigned int clk_rate, clk_cycle;
223 	enum lpi2c_imx_pincfg pincfg;
224 	unsigned int temp;
225 
226 	lpi2c_imx_set_mode(lpi2c_imx);
227 
228 	clk_rate = clk_get_rate(lpi2c_imx->clk);
229 	if (lpi2c_imx->mode == HS || lpi2c_imx->mode == ULTRA_FAST)
230 		filt = 0;
231 	else
232 		filt = 2;
233 
234 	for (prescale = 0; prescale <= 7; prescale++) {
235 		clk_cycle = clk_rate / ((1 << prescale) * lpi2c_imx->bitrate)
236 			    - 3 - (filt >> 1);
237 		clkhi = (clk_cycle + I2C_CLK_RATIO) / (I2C_CLK_RATIO + 1);
238 		clklo = clk_cycle - clkhi;
239 		if (clklo < 64)
240 			break;
241 	}
242 
243 	if (prescale > 7)
244 		return -EINVAL;
245 
246 	/* set MCFGR1: PINCFG, PRESCALE, IGNACK */
247 	if (lpi2c_imx->mode == ULTRA_FAST)
248 		pincfg = TWO_PIN_OO;
249 	else
250 		pincfg = TWO_PIN_OD;
251 	temp = prescale | pincfg << 24;
252 
253 	if (lpi2c_imx->mode == ULTRA_FAST)
254 		temp |= MCFGR1_IGNACK;
255 
256 	writel(temp, lpi2c_imx->base + LPI2C_MCFGR1);
257 
258 	/* set MCFGR2: FILTSDA, FILTSCL */
259 	temp = (filt << 16) | (filt << 24);
260 	writel(temp, lpi2c_imx->base + LPI2C_MCFGR2);
261 
262 	/* set MCCR: DATAVD, SETHOLD, CLKHI, CLKLO */
263 	sethold = clkhi;
264 	datavd = clkhi >> 1;
265 	temp = datavd << 24 | sethold << 16 | clkhi << 8 | clklo;
266 
267 	if (lpi2c_imx->mode == HS)
268 		writel(temp, lpi2c_imx->base + LPI2C_MCCR1);
269 	else
270 		writel(temp, lpi2c_imx->base + LPI2C_MCCR0);
271 
272 	return 0;
273 }
274 
275 static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
276 {
277 	unsigned int temp;
278 	int ret;
279 
280 	ret = pm_runtime_get_sync(lpi2c_imx->adapter.dev.parent);
281 	if (ret < 0)
282 		return ret;
283 
284 	temp = MCR_RST;
285 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
286 	writel(0, lpi2c_imx->base + LPI2C_MCR);
287 
288 	ret = lpi2c_imx_config(lpi2c_imx);
289 	if (ret)
290 		goto rpm_put;
291 
292 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
293 	temp |= MCR_MEN;
294 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
295 
296 	return 0;
297 
298 rpm_put:
299 	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
300 	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
301 
302 	return ret;
303 }
304 
305 static int lpi2c_imx_master_disable(struct lpi2c_imx_struct *lpi2c_imx)
306 {
307 	u32 temp;
308 
309 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
310 	temp &= ~MCR_MEN;
311 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
312 
313 	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
314 	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
315 
316 	return 0;
317 }
318 
319 static int lpi2c_imx_msg_complete(struct lpi2c_imx_struct *lpi2c_imx)
320 {
321 	unsigned long timeout;
322 
323 	timeout = wait_for_completion_timeout(&lpi2c_imx->complete, HZ);
324 
325 	return timeout ? 0 : -ETIMEDOUT;
326 }
327 
328 static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct *lpi2c_imx)
329 {
330 	unsigned long orig_jiffies = jiffies;
331 	u32 txcnt;
332 
333 	do {
334 		txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
335 
336 		if (readl(lpi2c_imx->base + LPI2C_MSR) & MSR_NDF) {
337 			dev_dbg(&lpi2c_imx->adapter.dev, "NDF detected\n");
338 			return -EIO;
339 		}
340 
341 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
342 			dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n");
343 			return -ETIMEDOUT;
344 		}
345 		schedule();
346 
347 	} while (txcnt);
348 
349 	return 0;
350 }
351 
352 static void lpi2c_imx_set_tx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
353 {
354 	writel(lpi2c_imx->txfifosize >> 1, lpi2c_imx->base + LPI2C_MFCR);
355 }
356 
357 static void lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
358 {
359 	unsigned int temp, remaining;
360 
361 	remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
362 
363 	if (remaining > (lpi2c_imx->rxfifosize >> 1))
364 		temp = lpi2c_imx->rxfifosize >> 1;
365 	else
366 		temp = 0;
367 
368 	writel(temp << 16, lpi2c_imx->base + LPI2C_MFCR);
369 }
370 
371 static void lpi2c_imx_write_txfifo(struct lpi2c_imx_struct *lpi2c_imx)
372 {
373 	unsigned int data, txcnt;
374 
375 	txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
376 
377 	while (txcnt < lpi2c_imx->txfifosize) {
378 		if (lpi2c_imx->delivered == lpi2c_imx->msglen)
379 			break;
380 
381 		data = lpi2c_imx->tx_buf[lpi2c_imx->delivered++];
382 		writel(data, lpi2c_imx->base + LPI2C_MTDR);
383 		txcnt++;
384 	}
385 
386 	if (lpi2c_imx->delivered < lpi2c_imx->msglen)
387 		lpi2c_imx_intctrl(lpi2c_imx, MIER_TDIE | MIER_NDIE);
388 	else
389 		complete(&lpi2c_imx->complete);
390 }
391 
392 static void lpi2c_imx_read_rxfifo(struct lpi2c_imx_struct *lpi2c_imx)
393 {
394 	unsigned int blocklen, remaining;
395 	unsigned int temp, data;
396 
397 	do {
398 		data = readl(lpi2c_imx->base + LPI2C_MRDR);
399 		if (data & MRDR_RXEMPTY)
400 			break;
401 
402 		lpi2c_imx->rx_buf[lpi2c_imx->delivered++] = data & 0xff;
403 	} while (1);
404 
405 	/*
406 	 * First byte is the length of remaining packet in the SMBus block
407 	 * data read. Add it to msgs->len.
408 	 */
409 	if (lpi2c_imx->block_data) {
410 		blocklen = lpi2c_imx->rx_buf[0];
411 		lpi2c_imx->msglen += blocklen;
412 	}
413 
414 	remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
415 
416 	if (!remaining) {
417 		complete(&lpi2c_imx->complete);
418 		return;
419 	}
420 
421 	/* not finished, still waiting for rx data */
422 	lpi2c_imx_set_rx_watermark(lpi2c_imx);
423 
424 	/* multiple receive commands */
425 	if (lpi2c_imx->block_data) {
426 		lpi2c_imx->block_data = 0;
427 		temp = remaining;
428 		temp |= (RECV_DATA << 8);
429 		writel(temp, lpi2c_imx->base + LPI2C_MTDR);
430 	} else if (!(lpi2c_imx->delivered & 0xff)) {
431 		temp = (remaining > CHUNK_DATA ? CHUNK_DATA : remaining) - 1;
432 		temp |= (RECV_DATA << 8);
433 		writel(temp, lpi2c_imx->base + LPI2C_MTDR);
434 	}
435 
436 	lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE);
437 }
438 
439 static void lpi2c_imx_write(struct lpi2c_imx_struct *lpi2c_imx,
440 			    struct i2c_msg *msgs)
441 {
442 	lpi2c_imx->tx_buf = msgs->buf;
443 	lpi2c_imx_set_tx_watermark(lpi2c_imx);
444 	lpi2c_imx_write_txfifo(lpi2c_imx);
445 }
446 
447 static void lpi2c_imx_read(struct lpi2c_imx_struct *lpi2c_imx,
448 			   struct i2c_msg *msgs)
449 {
450 	unsigned int temp;
451 
452 	lpi2c_imx->rx_buf = msgs->buf;
453 	lpi2c_imx->block_data = msgs->flags & I2C_M_RECV_LEN;
454 
455 	lpi2c_imx_set_rx_watermark(lpi2c_imx);
456 	temp = msgs->len > CHUNK_DATA ? CHUNK_DATA - 1 : msgs->len - 1;
457 	temp |= (RECV_DATA << 8);
458 	writel(temp, lpi2c_imx->base + LPI2C_MTDR);
459 
460 	lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE | MIER_NDIE);
461 }
462 
463 static int lpi2c_imx_xfer(struct i2c_adapter *adapter,
464 			  struct i2c_msg *msgs, int num)
465 {
466 	struct lpi2c_imx_struct *lpi2c_imx = i2c_get_adapdata(adapter);
467 	unsigned int temp;
468 	int i, result;
469 
470 	result = lpi2c_imx_master_enable(lpi2c_imx);
471 	if (result)
472 		return result;
473 
474 	for (i = 0; i < num; i++) {
475 		result = lpi2c_imx_start(lpi2c_imx, &msgs[i]);
476 		if (result)
477 			goto disable;
478 
479 		/* quick smbus */
480 		if (num == 1 && msgs[0].len == 0)
481 			goto stop;
482 
483 		lpi2c_imx->delivered = 0;
484 		lpi2c_imx->msglen = msgs[i].len;
485 		init_completion(&lpi2c_imx->complete);
486 
487 		if (msgs[i].flags & I2C_M_RD)
488 			lpi2c_imx_read(lpi2c_imx, &msgs[i]);
489 		else
490 			lpi2c_imx_write(lpi2c_imx, &msgs[i]);
491 
492 		result = lpi2c_imx_msg_complete(lpi2c_imx);
493 		if (result)
494 			goto stop;
495 
496 		if (!(msgs[i].flags & I2C_M_RD)) {
497 			result = lpi2c_imx_txfifo_empty(lpi2c_imx);
498 			if (result)
499 				goto stop;
500 		}
501 	}
502 
503 stop:
504 	lpi2c_imx_stop(lpi2c_imx);
505 
506 	temp = readl(lpi2c_imx->base + LPI2C_MSR);
507 	if ((temp & MSR_NDF) && !result)
508 		result = -EIO;
509 
510 disable:
511 	lpi2c_imx_master_disable(lpi2c_imx);
512 
513 	dev_dbg(&lpi2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
514 		(result < 0) ? "error" : "success msg",
515 		(result < 0) ? result : num);
516 
517 	return (result < 0) ? result : num;
518 }
519 
520 static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id)
521 {
522 	struct lpi2c_imx_struct *lpi2c_imx = dev_id;
523 	unsigned int temp;
524 
525 	lpi2c_imx_intctrl(lpi2c_imx, 0);
526 	temp = readl(lpi2c_imx->base + LPI2C_MSR);
527 
528 	if (temp & MSR_RDF)
529 		lpi2c_imx_read_rxfifo(lpi2c_imx);
530 
531 	if (temp & MSR_TDF)
532 		lpi2c_imx_write_txfifo(lpi2c_imx);
533 
534 	if (temp & MSR_NDF)
535 		complete(&lpi2c_imx->complete);
536 
537 	return IRQ_HANDLED;
538 }
539 
540 static u32 lpi2c_imx_func(struct i2c_adapter *adapter)
541 {
542 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
543 		I2C_FUNC_SMBUS_READ_BLOCK_DATA;
544 }
545 
546 static const struct i2c_algorithm lpi2c_imx_algo = {
547 	.master_xfer	= lpi2c_imx_xfer,
548 	.functionality	= lpi2c_imx_func,
549 };
550 
551 static const struct of_device_id lpi2c_imx_of_match[] = {
552 	{ .compatible = "fsl,imx7ulp-lpi2c" },
553 	{ .compatible = "fsl,imx8dv-lpi2c" },
554 	{ },
555 };
556 MODULE_DEVICE_TABLE(of, lpi2c_imx_of_match);
557 
558 static int lpi2c_imx_probe(struct platform_device *pdev)
559 {
560 	struct lpi2c_imx_struct *lpi2c_imx;
561 	struct resource *res;
562 	unsigned int temp;
563 	int irq, ret;
564 
565 	lpi2c_imx = devm_kzalloc(&pdev->dev, sizeof(*lpi2c_imx), GFP_KERNEL);
566 	if (!lpi2c_imx)
567 		return -ENOMEM;
568 
569 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
570 	lpi2c_imx->base = devm_ioremap_resource(&pdev->dev, res);
571 	if (IS_ERR(lpi2c_imx->base))
572 		return PTR_ERR(lpi2c_imx->base);
573 
574 	irq = platform_get_irq(pdev, 0);
575 	if (irq < 0) {
576 		dev_err(&pdev->dev, "can't get irq number\n");
577 		return irq;
578 	}
579 
580 	lpi2c_imx->adapter.owner	= THIS_MODULE;
581 	lpi2c_imx->adapter.algo		= &lpi2c_imx_algo;
582 	lpi2c_imx->adapter.dev.parent	= &pdev->dev;
583 	lpi2c_imx->adapter.dev.of_node	= pdev->dev.of_node;
584 	strlcpy(lpi2c_imx->adapter.name, pdev->name,
585 		sizeof(lpi2c_imx->adapter.name));
586 
587 	lpi2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
588 	if (IS_ERR(lpi2c_imx->clk)) {
589 		dev_err(&pdev->dev, "can't get I2C peripheral clock\n");
590 		return PTR_ERR(lpi2c_imx->clk);
591 	}
592 
593 	ret = of_property_read_u32(pdev->dev.of_node,
594 				   "clock-frequency", &lpi2c_imx->bitrate);
595 	if (ret)
596 		lpi2c_imx->bitrate = LPI2C_DEFAULT_RATE;
597 
598 	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, 0,
599 			       pdev->name, lpi2c_imx);
600 	if (ret) {
601 		dev_err(&pdev->dev, "can't claim irq %d\n", irq);
602 		return ret;
603 	}
604 
605 	i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx);
606 	platform_set_drvdata(pdev, lpi2c_imx);
607 
608 	ret = clk_prepare_enable(lpi2c_imx->clk);
609 	if (ret) {
610 		dev_err(&pdev->dev, "clk enable failed %d\n", ret);
611 		return ret;
612 	}
613 
614 	pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
615 	pm_runtime_use_autosuspend(&pdev->dev);
616 	pm_runtime_get_noresume(&pdev->dev);
617 	pm_runtime_set_active(&pdev->dev);
618 	pm_runtime_enable(&pdev->dev);
619 
620 	temp = readl(lpi2c_imx->base + LPI2C_PARAM);
621 	lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
622 	lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
623 
624 	ret = i2c_add_adapter(&lpi2c_imx->adapter);
625 	if (ret)
626 		goto rpm_disable;
627 
628 	pm_runtime_mark_last_busy(&pdev->dev);
629 	pm_runtime_put_autosuspend(&pdev->dev);
630 
631 	dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
632 
633 	return 0;
634 
635 rpm_disable:
636 	pm_runtime_put(&pdev->dev);
637 	pm_runtime_disable(&pdev->dev);
638 	pm_runtime_dont_use_autosuspend(&pdev->dev);
639 
640 	return ret;
641 }
642 
643 static int lpi2c_imx_remove(struct platform_device *pdev)
644 {
645 	struct lpi2c_imx_struct *lpi2c_imx = platform_get_drvdata(pdev);
646 
647 	i2c_del_adapter(&lpi2c_imx->adapter);
648 
649 	pm_runtime_disable(&pdev->dev);
650 	pm_runtime_dont_use_autosuspend(&pdev->dev);
651 
652 	return 0;
653 }
654 
655 #ifdef CONFIG_PM_SLEEP
656 static int lpi2c_runtime_suspend(struct device *dev)
657 {
658 	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
659 
660 	clk_disable_unprepare(lpi2c_imx->clk);
661 	pinctrl_pm_select_sleep_state(dev);
662 
663 	return 0;
664 }
665 
666 static int lpi2c_runtime_resume(struct device *dev)
667 {
668 	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
669 	int ret;
670 
671 	pinctrl_pm_select_default_state(dev);
672 	ret = clk_prepare_enable(lpi2c_imx->clk);
673 	if (ret) {
674 		dev_err(dev, "failed to enable I2C clock, ret=%d\n", ret);
675 		return ret;
676 	}
677 
678 	return 0;
679 }
680 
681 static const struct dev_pm_ops lpi2c_pm_ops = {
682 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
683 				      pm_runtime_force_resume)
684 	SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,
685 			   lpi2c_runtime_resume, NULL)
686 };
687 #define IMX_LPI2C_PM      (&lpi2c_pm_ops)
688 #else
689 #define IMX_LPI2C_PM      NULL
690 #endif
691 
692 static struct platform_driver lpi2c_imx_driver = {
693 	.probe = lpi2c_imx_probe,
694 	.remove = lpi2c_imx_remove,
695 	.driver = {
696 		.name = DRIVER_NAME,
697 		.of_match_table = lpi2c_imx_of_match,
698 		.pm = IMX_LPI2C_PM,
699 	},
700 };
701 
702 module_platform_driver(lpi2c_imx_driver);
703 
704 MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
705 MODULE_DESCRIPTION("I2C adapter driver for LPI2C bus");
706 MODULE_LICENSE("GPL");
707