xref: /linux/drivers/i2c/busses/i2c-imx-lpi2c.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
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/sched.h>
34 #include <linux/slab.h>
35 
36 #define DRIVER_NAME "imx-lpi2c"
37 
38 #define LPI2C_PARAM	0x04	/* i2c RX/TX FIFO size */
39 #define LPI2C_MCR	0x10	/* i2c contrl register */
40 #define LPI2C_MSR	0x14	/* i2c status register */
41 #define LPI2C_MIER	0x18	/* i2c interrupt enable */
42 #define LPI2C_MCFGR0	0x20	/* i2c master configuration */
43 #define LPI2C_MCFGR1	0x24	/* i2c master configuration */
44 #define LPI2C_MCFGR2	0x28	/* i2c master configuration */
45 #define LPI2C_MCFGR3	0x2C	/* i2c master configuration */
46 #define LPI2C_MCCR0	0x48	/* i2c master clk configuration */
47 #define LPI2C_MCCR1	0x50	/* i2c master clk configuration */
48 #define LPI2C_MFCR	0x58	/* i2c master FIFO control */
49 #define LPI2C_MFSR	0x5C	/* i2c master FIFO status */
50 #define LPI2C_MTDR	0x60	/* i2c master TX data register */
51 #define LPI2C_MRDR	0x70	/* i2c master RX data register */
52 
53 /* i2c command */
54 #define TRAN_DATA	0X00
55 #define RECV_DATA	0X01
56 #define GEN_STOP	0X02
57 #define RECV_DISCARD	0X03
58 #define GEN_START	0X04
59 #define START_NACK	0X05
60 #define START_HIGH	0X06
61 #define START_HIGH_NACK	0X07
62 
63 #define MCR_MEN		BIT(0)
64 #define MCR_RST		BIT(1)
65 #define MCR_DOZEN	BIT(2)
66 #define MCR_DBGEN	BIT(3)
67 #define MCR_RTF		BIT(8)
68 #define MCR_RRF		BIT(9)
69 #define MSR_TDF		BIT(0)
70 #define MSR_RDF		BIT(1)
71 #define MSR_SDF		BIT(9)
72 #define MSR_NDF		BIT(10)
73 #define MSR_ALF		BIT(11)
74 #define MSR_MBF		BIT(24)
75 #define MSR_BBF		BIT(25)
76 #define MIER_TDIE	BIT(0)
77 #define MIER_RDIE	BIT(1)
78 #define MIER_SDIE	BIT(9)
79 #define MIER_NDIE	BIT(10)
80 #define MCFGR1_AUTOSTOP	BIT(8)
81 #define MCFGR1_IGNACK	BIT(9)
82 #define MRDR_RXEMPTY	BIT(14)
83 
84 #define I2C_CLK_RATIO	2
85 #define CHUNK_DATA	256
86 
87 #define LPI2C_DEFAULT_RATE	100000
88 #define STARDARD_MAX_BITRATE	400000
89 #define FAST_MAX_BITRATE	1000000
90 #define FAST_PLUS_MAX_BITRATE	3400000
91 #define HIGHSPEED_MAX_BITRATE	5000000
92 
93 enum lpi2c_imx_mode {
94 	STANDARD,	/* 100+Kbps */
95 	FAST,		/* 400+Kbps */
96 	FAST_PLUS,	/* 1.0+Mbps */
97 	HS,		/* 3.4+Mbps */
98 	ULTRA_FAST,	/* 5.0+Mbps */
99 };
100 
101 enum lpi2c_imx_pincfg {
102 	TWO_PIN_OD,
103 	TWO_PIN_OO,
104 	TWO_PIN_PP,
105 	FOUR_PIN_PP,
106 };
107 
108 struct lpi2c_imx_struct {
109 	struct i2c_adapter	adapter;
110 	struct clk		*clk;
111 	void __iomem		*base;
112 	__u8			*rx_buf;
113 	__u8			*tx_buf;
114 	struct completion	complete;
115 	unsigned int		msglen;
116 	unsigned int		delivered;
117 	unsigned int		block_data;
118 	unsigned int		bitrate;
119 	unsigned int		txfifosize;
120 	unsigned int		rxfifosize;
121 	enum lpi2c_imx_mode	mode;
122 };
123 
124 static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx,
125 			      unsigned int enable)
126 {
127 	writel(enable, lpi2c_imx->base + LPI2C_MIER);
128 }
129 
130 static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct *lpi2c_imx)
131 {
132 	unsigned long orig_jiffies = jiffies;
133 	unsigned int temp;
134 
135 	while (1) {
136 		temp = readl(lpi2c_imx->base + LPI2C_MSR);
137 
138 		/* check for arbitration lost, clear if set */
139 		if (temp & MSR_ALF) {
140 			writel(temp, lpi2c_imx->base + LPI2C_MSR);
141 			return -EAGAIN;
142 		}
143 
144 		if (temp & (MSR_BBF | MSR_MBF))
145 			break;
146 
147 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
148 			dev_dbg(&lpi2c_imx->adapter.dev, "bus not work\n");
149 			return -ETIMEDOUT;
150 		}
151 		schedule();
152 	}
153 
154 	return 0;
155 }
156 
157 static void lpi2c_imx_set_mode(struct lpi2c_imx_struct *lpi2c_imx)
158 {
159 	unsigned int bitrate = lpi2c_imx->bitrate;
160 	enum lpi2c_imx_mode mode;
161 
162 	if (bitrate < STARDARD_MAX_BITRATE)
163 		mode = STANDARD;
164 	else if (bitrate < FAST_MAX_BITRATE)
165 		mode = FAST;
166 	else if (bitrate < FAST_PLUS_MAX_BITRATE)
167 		mode = FAST_PLUS;
168 	else if (bitrate < HIGHSPEED_MAX_BITRATE)
169 		mode = HS;
170 	else
171 		mode = ULTRA_FAST;
172 
173 	lpi2c_imx->mode = mode;
174 }
175 
176 static int lpi2c_imx_start(struct lpi2c_imx_struct *lpi2c_imx,
177 			   struct i2c_msg *msgs)
178 {
179 	unsigned int temp;
180 	u8 read;
181 
182 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
183 	temp |= MCR_RRF | MCR_RTF;
184 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
185 	writel(0x7f00, lpi2c_imx->base + LPI2C_MSR);
186 
187 	read = msgs->flags & I2C_M_RD;
188 	temp = (msgs->addr << 1 | read) | (GEN_START << 8);
189 	writel(temp, lpi2c_imx->base + LPI2C_MTDR);
190 
191 	return lpi2c_imx_bus_busy(lpi2c_imx);
192 }
193 
194 static void lpi2c_imx_stop(struct lpi2c_imx_struct *lpi2c_imx)
195 {
196 	unsigned long orig_jiffies = jiffies;
197 	unsigned int temp;
198 
199 	writel(GEN_STOP << 8, lpi2c_imx->base + LPI2C_MTDR);
200 
201 	do {
202 		temp = readl(lpi2c_imx->base + LPI2C_MSR);
203 		if (temp & MSR_SDF)
204 			break;
205 
206 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
207 			dev_dbg(&lpi2c_imx->adapter.dev, "stop timeout\n");
208 			break;
209 		}
210 		schedule();
211 
212 	} while (1);
213 }
214 
215 /* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 */
216 static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx)
217 {
218 	u8 prescale, filt, sethold, clkhi, clklo, datavd;
219 	unsigned int clk_rate, clk_cycle;
220 	enum lpi2c_imx_pincfg pincfg;
221 	unsigned int temp;
222 
223 	lpi2c_imx_set_mode(lpi2c_imx);
224 
225 	clk_rate = clk_get_rate(lpi2c_imx->clk);
226 	if (lpi2c_imx->mode == HS || lpi2c_imx->mode == ULTRA_FAST)
227 		filt = 0;
228 	else
229 		filt = 2;
230 
231 	for (prescale = 0; prescale <= 7; prescale++) {
232 		clk_cycle = clk_rate / ((1 << prescale) * lpi2c_imx->bitrate)
233 			    - 3 - (filt >> 1);
234 		clkhi = (clk_cycle + I2C_CLK_RATIO) / (I2C_CLK_RATIO + 1);
235 		clklo = clk_cycle - clkhi;
236 		if (clklo < 64)
237 			break;
238 	}
239 
240 	if (prescale > 7)
241 		return -EINVAL;
242 
243 	/* set MCFGR1: PINCFG, PRESCALE, IGNACK */
244 	if (lpi2c_imx->mode == ULTRA_FAST)
245 		pincfg = TWO_PIN_OO;
246 	else
247 		pincfg = TWO_PIN_OD;
248 	temp = prescale | pincfg << 24;
249 
250 	if (lpi2c_imx->mode == ULTRA_FAST)
251 		temp |= MCFGR1_IGNACK;
252 
253 	writel(temp, lpi2c_imx->base + LPI2C_MCFGR1);
254 
255 	/* set MCFGR2: FILTSDA, FILTSCL */
256 	temp = (filt << 16) | (filt << 24);
257 	writel(temp, lpi2c_imx->base + LPI2C_MCFGR2);
258 
259 	/* set MCCR: DATAVD, SETHOLD, CLKHI, CLKLO */
260 	sethold = clkhi;
261 	datavd = clkhi >> 1;
262 	temp = datavd << 24 | sethold << 16 | clkhi << 8 | clklo;
263 
264 	if (lpi2c_imx->mode == HS)
265 		writel(temp, lpi2c_imx->base + LPI2C_MCCR1);
266 	else
267 		writel(temp, lpi2c_imx->base + LPI2C_MCCR0);
268 
269 	return 0;
270 }
271 
272 static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
273 {
274 	unsigned int temp;
275 	int ret;
276 
277 	ret = clk_enable(lpi2c_imx->clk);
278 	if (ret)
279 		return ret;
280 
281 	temp = MCR_RST;
282 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
283 	writel(0, lpi2c_imx->base + LPI2C_MCR);
284 
285 	ret = lpi2c_imx_config(lpi2c_imx);
286 	if (ret)
287 		goto clk_disable;
288 
289 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
290 	temp |= MCR_MEN;
291 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
292 
293 	return 0;
294 
295 clk_disable:
296 	clk_disable(lpi2c_imx->clk);
297 
298 	return ret;
299 }
300 
301 static int lpi2c_imx_master_disable(struct lpi2c_imx_struct *lpi2c_imx)
302 {
303 	u32 temp;
304 
305 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
306 	temp &= ~MCR_MEN;
307 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
308 
309 	clk_disable(lpi2c_imx->clk);
310 
311 	return 0;
312 }
313 
314 static int lpi2c_imx_msg_complete(struct lpi2c_imx_struct *lpi2c_imx)
315 {
316 	unsigned long timeout;
317 
318 	timeout = wait_for_completion_timeout(&lpi2c_imx->complete, HZ);
319 
320 	return timeout ? 0 : -ETIMEDOUT;
321 }
322 
323 static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct *lpi2c_imx)
324 {
325 	unsigned long orig_jiffies = jiffies;
326 	u32 txcnt;
327 
328 	do {
329 		txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
330 
331 		if (readl(lpi2c_imx->base + LPI2C_MSR) & MSR_NDF) {
332 			dev_dbg(&lpi2c_imx->adapter.dev, "NDF detected\n");
333 			return -EIO;
334 		}
335 
336 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
337 			dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n");
338 			return -ETIMEDOUT;
339 		}
340 		schedule();
341 
342 	} while (txcnt);
343 
344 	return 0;
345 }
346 
347 static void lpi2c_imx_set_tx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
348 {
349 	writel(lpi2c_imx->txfifosize >> 1, lpi2c_imx->base + LPI2C_MFCR);
350 }
351 
352 static void lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
353 {
354 	unsigned int temp, remaining;
355 
356 	remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
357 
358 	if (remaining > (lpi2c_imx->rxfifosize >> 1))
359 		temp = lpi2c_imx->rxfifosize >> 1;
360 	else
361 		temp = 0;
362 
363 	writel(temp << 16, lpi2c_imx->base + LPI2C_MFCR);
364 }
365 
366 static void lpi2c_imx_write_txfifo(struct lpi2c_imx_struct *lpi2c_imx)
367 {
368 	unsigned int data, txcnt;
369 
370 	txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
371 
372 	while (txcnt < lpi2c_imx->txfifosize) {
373 		if (lpi2c_imx->delivered == lpi2c_imx->msglen)
374 			break;
375 
376 		data = lpi2c_imx->tx_buf[lpi2c_imx->delivered++];
377 		writel(data, lpi2c_imx->base + LPI2C_MTDR);
378 		txcnt++;
379 	}
380 
381 	if (lpi2c_imx->delivered < lpi2c_imx->msglen)
382 		lpi2c_imx_intctrl(lpi2c_imx, MIER_TDIE | MIER_NDIE);
383 	else
384 		complete(&lpi2c_imx->complete);
385 }
386 
387 static void lpi2c_imx_read_rxfifo(struct lpi2c_imx_struct *lpi2c_imx)
388 {
389 	unsigned int blocklen, remaining;
390 	unsigned int temp, data;
391 
392 	do {
393 		data = readl(lpi2c_imx->base + LPI2C_MRDR);
394 		if (data & MRDR_RXEMPTY)
395 			break;
396 
397 		lpi2c_imx->rx_buf[lpi2c_imx->delivered++] = data & 0xff;
398 	} while (1);
399 
400 	/*
401 	 * First byte is the length of remaining packet in the SMBus block
402 	 * data read. Add it to msgs->len.
403 	 */
404 	if (lpi2c_imx->block_data) {
405 		blocklen = lpi2c_imx->rx_buf[0];
406 		lpi2c_imx->msglen += blocklen;
407 	}
408 
409 	remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
410 
411 	if (!remaining) {
412 		complete(&lpi2c_imx->complete);
413 		return;
414 	}
415 
416 	/* not finished, still waiting for rx data */
417 	lpi2c_imx_set_rx_watermark(lpi2c_imx);
418 
419 	/* multiple receive commands */
420 	if (lpi2c_imx->block_data) {
421 		lpi2c_imx->block_data = 0;
422 		temp = remaining;
423 		temp |= (RECV_DATA << 8);
424 		writel(temp, lpi2c_imx->base + LPI2C_MTDR);
425 	} else if (!(lpi2c_imx->delivered & 0xff)) {
426 		temp = (remaining > CHUNK_DATA ? CHUNK_DATA : remaining) - 1;
427 		temp |= (RECV_DATA << 8);
428 		writel(temp, lpi2c_imx->base + LPI2C_MTDR);
429 	}
430 
431 	lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE);
432 }
433 
434 static void lpi2c_imx_write(struct lpi2c_imx_struct *lpi2c_imx,
435 			    struct i2c_msg *msgs)
436 {
437 	lpi2c_imx->tx_buf = msgs->buf;
438 	lpi2c_imx_set_tx_watermark(lpi2c_imx);
439 	lpi2c_imx_write_txfifo(lpi2c_imx);
440 }
441 
442 static void lpi2c_imx_read(struct lpi2c_imx_struct *lpi2c_imx,
443 			   struct i2c_msg *msgs)
444 {
445 	unsigned int temp;
446 
447 	lpi2c_imx->rx_buf = msgs->buf;
448 	lpi2c_imx->block_data = msgs->flags & I2C_M_RECV_LEN;
449 
450 	lpi2c_imx_set_rx_watermark(lpi2c_imx);
451 	temp = msgs->len > CHUNK_DATA ? CHUNK_DATA - 1 : msgs->len - 1;
452 	temp |= (RECV_DATA << 8);
453 	writel(temp, lpi2c_imx->base + LPI2C_MTDR);
454 
455 	lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE | MIER_NDIE);
456 }
457 
458 static int lpi2c_imx_xfer(struct i2c_adapter *adapter,
459 			  struct i2c_msg *msgs, int num)
460 {
461 	struct lpi2c_imx_struct *lpi2c_imx = i2c_get_adapdata(adapter);
462 	unsigned int temp;
463 	int i, result;
464 
465 	result = lpi2c_imx_master_enable(lpi2c_imx);
466 	if (result)
467 		return result;
468 
469 	for (i = 0; i < num; i++) {
470 		result = lpi2c_imx_start(lpi2c_imx, &msgs[i]);
471 		if (result)
472 			goto disable;
473 
474 		/* quick smbus */
475 		if (num == 1 && msgs[0].len == 0)
476 			goto stop;
477 
478 		lpi2c_imx->delivered = 0;
479 		lpi2c_imx->msglen = msgs[i].len;
480 		init_completion(&lpi2c_imx->complete);
481 
482 		if (msgs[i].flags & I2C_M_RD)
483 			lpi2c_imx_read(lpi2c_imx, &msgs[i]);
484 		else
485 			lpi2c_imx_write(lpi2c_imx, &msgs[i]);
486 
487 		result = lpi2c_imx_msg_complete(lpi2c_imx);
488 		if (result)
489 			goto stop;
490 
491 		if (!(msgs[i].flags & I2C_M_RD)) {
492 			result = lpi2c_imx_txfifo_empty(lpi2c_imx);
493 			if (result)
494 				goto stop;
495 		}
496 	}
497 
498 stop:
499 	lpi2c_imx_stop(lpi2c_imx);
500 
501 	temp = readl(lpi2c_imx->base + LPI2C_MSR);
502 	if ((temp & MSR_NDF) && !result)
503 		result = -EIO;
504 
505 disable:
506 	lpi2c_imx_master_disable(lpi2c_imx);
507 
508 	dev_dbg(&lpi2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
509 		(result < 0) ? "error" : "success msg",
510 		(result < 0) ? result : num);
511 
512 	return (result < 0) ? result : num;
513 }
514 
515 static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id)
516 {
517 	struct lpi2c_imx_struct *lpi2c_imx = dev_id;
518 	unsigned int temp;
519 
520 	lpi2c_imx_intctrl(lpi2c_imx, 0);
521 	temp = readl(lpi2c_imx->base + LPI2C_MSR);
522 
523 	if (temp & MSR_RDF)
524 		lpi2c_imx_read_rxfifo(lpi2c_imx);
525 
526 	if (temp & MSR_TDF)
527 		lpi2c_imx_write_txfifo(lpi2c_imx);
528 
529 	if (temp & MSR_NDF)
530 		complete(&lpi2c_imx->complete);
531 
532 	return IRQ_HANDLED;
533 }
534 
535 static u32 lpi2c_imx_func(struct i2c_adapter *adapter)
536 {
537 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
538 		I2C_FUNC_SMBUS_READ_BLOCK_DATA;
539 }
540 
541 static const struct i2c_algorithm lpi2c_imx_algo = {
542 	.master_xfer	= lpi2c_imx_xfer,
543 	.functionality	= lpi2c_imx_func,
544 };
545 
546 static const struct of_device_id lpi2c_imx_of_match[] = {
547 	{ .compatible = "fsl,imx7ulp-lpi2c" },
548 	{ .compatible = "fsl,imx8dv-lpi2c" },
549 	{ },
550 };
551 MODULE_DEVICE_TABLE(of, lpi2c_imx_of_match);
552 
553 static int lpi2c_imx_probe(struct platform_device *pdev)
554 {
555 	struct lpi2c_imx_struct *lpi2c_imx;
556 	struct resource *res;
557 	unsigned int temp;
558 	int irq, ret;
559 
560 	lpi2c_imx = devm_kzalloc(&pdev->dev, sizeof(*lpi2c_imx), GFP_KERNEL);
561 	if (!lpi2c_imx)
562 		return -ENOMEM;
563 
564 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
565 	lpi2c_imx->base = devm_ioremap_resource(&pdev->dev, res);
566 	if (IS_ERR(lpi2c_imx->base))
567 		return PTR_ERR(lpi2c_imx->base);
568 
569 	irq = platform_get_irq(pdev, 0);
570 	if (irq < 0) {
571 		dev_err(&pdev->dev, "can't get irq number\n");
572 		return irq;
573 	}
574 
575 	lpi2c_imx->adapter.owner	= THIS_MODULE;
576 	lpi2c_imx->adapter.algo		= &lpi2c_imx_algo;
577 	lpi2c_imx->adapter.dev.parent	= &pdev->dev;
578 	lpi2c_imx->adapter.dev.of_node	= pdev->dev.of_node;
579 	strlcpy(lpi2c_imx->adapter.name, pdev->name,
580 		sizeof(lpi2c_imx->adapter.name));
581 
582 	lpi2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
583 	if (IS_ERR(lpi2c_imx->clk)) {
584 		dev_err(&pdev->dev, "can't get I2C peripheral clock\n");
585 		return PTR_ERR(lpi2c_imx->clk);
586 	}
587 
588 	ret = of_property_read_u32(pdev->dev.of_node,
589 				   "clock-frequency", &lpi2c_imx->bitrate);
590 	if (ret)
591 		lpi2c_imx->bitrate = LPI2C_DEFAULT_RATE;
592 
593 	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, 0,
594 			       pdev->name, lpi2c_imx);
595 	if (ret) {
596 		dev_err(&pdev->dev, "can't claim irq %d\n", irq);
597 		return ret;
598 	}
599 
600 	i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx);
601 	platform_set_drvdata(pdev, lpi2c_imx);
602 
603 	ret = clk_prepare_enable(lpi2c_imx->clk);
604 	if (ret) {
605 		dev_err(&pdev->dev, "clk enable failed %d\n", ret);
606 		return ret;
607 	}
608 
609 	temp = readl(lpi2c_imx->base + LPI2C_PARAM);
610 	lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
611 	lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
612 
613 	clk_disable(lpi2c_imx->clk);
614 
615 	ret = i2c_add_adapter(&lpi2c_imx->adapter);
616 	if (ret)
617 		goto clk_unprepare;
618 
619 	dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
620 
621 	return 0;
622 
623 clk_unprepare:
624 	clk_unprepare(lpi2c_imx->clk);
625 
626 	return ret;
627 }
628 
629 static int lpi2c_imx_remove(struct platform_device *pdev)
630 {
631 	struct lpi2c_imx_struct *lpi2c_imx = platform_get_drvdata(pdev);
632 
633 	i2c_del_adapter(&lpi2c_imx->adapter);
634 
635 	clk_unprepare(lpi2c_imx->clk);
636 
637 	return 0;
638 }
639 
640 #ifdef CONFIG_PM_SLEEP
641 static int lpi2c_imx_suspend(struct device *dev)
642 {
643 	pinctrl_pm_select_sleep_state(dev);
644 
645 	return 0;
646 }
647 
648 static int lpi2c_imx_resume(struct device *dev)
649 {
650 	pinctrl_pm_select_default_state(dev);
651 
652 	return 0;
653 }
654 #endif
655 
656 static SIMPLE_DEV_PM_OPS(imx_lpi2c_pm, lpi2c_imx_suspend, lpi2c_imx_resume);
657 
658 static struct platform_driver lpi2c_imx_driver = {
659 	.probe = lpi2c_imx_probe,
660 	.remove = lpi2c_imx_remove,
661 	.driver = {
662 		.name = DRIVER_NAME,
663 		.of_match_table = lpi2c_imx_of_match,
664 		.pm = &imx_lpi2c_pm,
665 	},
666 };
667 
668 module_platform_driver(lpi2c_imx_driver);
669 
670 MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
671 MODULE_DESCRIPTION("I2C adapter driver for LPI2C bus");
672 MODULE_LICENSE("GPL");
673