1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * This is i.MX low power i2c controller driver.
4  *
5  * Copyright 2016 Freescale Semiconductor, Inc.
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/completion.h>
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/errno.h>
13 #include <linux/i2c.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/pinctrl/consumer.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/sched.h>
24 #include <linux/slab.h>
25 
26 #define DRIVER_NAME "imx-lpi2c"
27 
28 #define LPI2C_PARAM	0x04	/* i2c RX/TX FIFO size */
29 #define LPI2C_MCR	0x10	/* i2c contrl register */
30 #define LPI2C_MSR	0x14	/* i2c status register */
31 #define LPI2C_MIER	0x18	/* i2c interrupt enable */
32 #define LPI2C_MCFGR0	0x20	/* i2c master configuration */
33 #define LPI2C_MCFGR1	0x24	/* i2c master configuration */
34 #define LPI2C_MCFGR2	0x28	/* i2c master configuration */
35 #define LPI2C_MCFGR3	0x2C	/* i2c master configuration */
36 #define LPI2C_MCCR0	0x48	/* i2c master clk configuration */
37 #define LPI2C_MCCR1	0x50	/* i2c master clk configuration */
38 #define LPI2C_MFCR	0x58	/* i2c master FIFO control */
39 #define LPI2C_MFSR	0x5C	/* i2c master FIFO status */
40 #define LPI2C_MTDR	0x60	/* i2c master TX data register */
41 #define LPI2C_MRDR	0x70	/* i2c master RX data register */
42 
43 /* i2c command */
44 #define TRAN_DATA	0X00
45 #define RECV_DATA	0X01
46 #define GEN_STOP	0X02
47 #define RECV_DISCARD	0X03
48 #define GEN_START	0X04
49 #define START_NACK	0X05
50 #define START_HIGH	0X06
51 #define START_HIGH_NACK	0X07
52 
53 #define MCR_MEN		BIT(0)
54 #define MCR_RST		BIT(1)
55 #define MCR_DOZEN	BIT(2)
56 #define MCR_DBGEN	BIT(3)
57 #define MCR_RTF		BIT(8)
58 #define MCR_RRF		BIT(9)
59 #define MSR_TDF		BIT(0)
60 #define MSR_RDF		BIT(1)
61 #define MSR_SDF		BIT(9)
62 #define MSR_NDF		BIT(10)
63 #define MSR_ALF		BIT(11)
64 #define MSR_MBF		BIT(24)
65 #define MSR_BBF		BIT(25)
66 #define MIER_TDIE	BIT(0)
67 #define MIER_RDIE	BIT(1)
68 #define MIER_SDIE	BIT(9)
69 #define MIER_NDIE	BIT(10)
70 #define MCFGR1_AUTOSTOP	BIT(8)
71 #define MCFGR1_IGNACK	BIT(9)
72 #define MRDR_RXEMPTY	BIT(14)
73 
74 #define I2C_CLK_RATIO	2
75 #define CHUNK_DATA	256
76 
77 #define I2C_PM_TIMEOUT		10 /* ms */
78 
79 enum lpi2c_imx_mode {
80 	STANDARD,	/* 100+Kbps */
81 	FAST,		/* 400+Kbps */
82 	FAST_PLUS,	/* 1.0+Mbps */
83 	HS,		/* 3.4+Mbps */
84 	ULTRA_FAST,	/* 5.0+Mbps */
85 };
86 
87 enum lpi2c_imx_pincfg {
88 	TWO_PIN_OD,
89 	TWO_PIN_OO,
90 	TWO_PIN_PP,
91 	FOUR_PIN_PP,
92 };
93 
94 struct lpi2c_imx_struct {
95 	struct i2c_adapter	adapter;
96 	int			num_clks;
97 	struct clk_bulk_data	*clks;
98 	void __iomem		*base;
99 	__u8			*rx_buf;
100 	__u8			*tx_buf;
101 	struct completion	complete;
102 	unsigned int		msglen;
103 	unsigned int		delivered;
104 	unsigned int		block_data;
105 	unsigned int		bitrate;
106 	unsigned int		txfifosize;
107 	unsigned int		rxfifosize;
108 	enum lpi2c_imx_mode	mode;
109 };
110 
111 static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx,
112 			      unsigned int enable)
113 {
114 	writel(enable, lpi2c_imx->base + LPI2C_MIER);
115 }
116 
117 static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct *lpi2c_imx)
118 {
119 	unsigned long orig_jiffies = jiffies;
120 	unsigned int temp;
121 
122 	while (1) {
123 		temp = readl(lpi2c_imx->base + LPI2C_MSR);
124 
125 		/* check for arbitration lost, clear if set */
126 		if (temp & MSR_ALF) {
127 			writel(temp, lpi2c_imx->base + LPI2C_MSR);
128 			return -EAGAIN;
129 		}
130 
131 		if (temp & (MSR_BBF | MSR_MBF))
132 			break;
133 
134 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
135 			dev_dbg(&lpi2c_imx->adapter.dev, "bus not work\n");
136 			return -ETIMEDOUT;
137 		}
138 		schedule();
139 	}
140 
141 	return 0;
142 }
143 
144 static void lpi2c_imx_set_mode(struct lpi2c_imx_struct *lpi2c_imx)
145 {
146 	unsigned int bitrate = lpi2c_imx->bitrate;
147 	enum lpi2c_imx_mode mode;
148 
149 	if (bitrate < I2C_MAX_FAST_MODE_FREQ)
150 		mode = STANDARD;
151 	else if (bitrate < I2C_MAX_FAST_MODE_PLUS_FREQ)
152 		mode = FAST;
153 	else if (bitrate < I2C_MAX_HIGH_SPEED_MODE_FREQ)
154 		mode = FAST_PLUS;
155 	else if (bitrate < I2C_MAX_ULTRA_FAST_MODE_FREQ)
156 		mode = HS;
157 	else
158 		mode = ULTRA_FAST;
159 
160 	lpi2c_imx->mode = mode;
161 }
162 
163 static int lpi2c_imx_start(struct lpi2c_imx_struct *lpi2c_imx,
164 			   struct i2c_msg *msgs)
165 {
166 	unsigned int temp;
167 
168 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
169 	temp |= MCR_RRF | MCR_RTF;
170 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
171 	writel(0x7f00, lpi2c_imx->base + LPI2C_MSR);
172 
173 	temp = i2c_8bit_addr_from_msg(msgs) | (GEN_START << 8);
174 	writel(temp, lpi2c_imx->base + LPI2C_MTDR);
175 
176 	return lpi2c_imx_bus_busy(lpi2c_imx);
177 }
178 
179 static void lpi2c_imx_stop(struct lpi2c_imx_struct *lpi2c_imx)
180 {
181 	unsigned long orig_jiffies = jiffies;
182 	unsigned int temp;
183 
184 	writel(GEN_STOP << 8, lpi2c_imx->base + LPI2C_MTDR);
185 
186 	do {
187 		temp = readl(lpi2c_imx->base + LPI2C_MSR);
188 		if (temp & MSR_SDF)
189 			break;
190 
191 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
192 			dev_dbg(&lpi2c_imx->adapter.dev, "stop timeout\n");
193 			break;
194 		}
195 		schedule();
196 
197 	} while (1);
198 }
199 
200 /* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 */
201 static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx)
202 {
203 	u8 prescale, filt, sethold, datavd;
204 	unsigned int clk_rate, clk_cycle, clkhi, clklo;
205 	enum lpi2c_imx_pincfg pincfg;
206 	unsigned int temp;
207 
208 	lpi2c_imx_set_mode(lpi2c_imx);
209 
210 	clk_rate = clk_get_rate(lpi2c_imx->clks[0].clk);
211 	if (lpi2c_imx->mode == HS || lpi2c_imx->mode == ULTRA_FAST)
212 		filt = 0;
213 	else
214 		filt = 2;
215 
216 	for (prescale = 0; prescale <= 7; prescale++) {
217 		clk_cycle = clk_rate / ((1 << prescale) * lpi2c_imx->bitrate)
218 			    - 3 - (filt >> 1);
219 		clkhi = DIV_ROUND_UP(clk_cycle, I2C_CLK_RATIO + 1);
220 		clklo = clk_cycle - clkhi;
221 		if (clklo < 64)
222 			break;
223 	}
224 
225 	if (prescale > 7)
226 		return -EINVAL;
227 
228 	/* set MCFGR1: PINCFG, PRESCALE, IGNACK */
229 	if (lpi2c_imx->mode == ULTRA_FAST)
230 		pincfg = TWO_PIN_OO;
231 	else
232 		pincfg = TWO_PIN_OD;
233 	temp = prescale | pincfg << 24;
234 
235 	if (lpi2c_imx->mode == ULTRA_FAST)
236 		temp |= MCFGR1_IGNACK;
237 
238 	writel(temp, lpi2c_imx->base + LPI2C_MCFGR1);
239 
240 	/* set MCFGR2: FILTSDA, FILTSCL */
241 	temp = (filt << 16) | (filt << 24);
242 	writel(temp, lpi2c_imx->base + LPI2C_MCFGR2);
243 
244 	/* set MCCR: DATAVD, SETHOLD, CLKHI, CLKLO */
245 	sethold = clkhi;
246 	datavd = clkhi >> 1;
247 	temp = datavd << 24 | sethold << 16 | clkhi << 8 | clklo;
248 
249 	if (lpi2c_imx->mode == HS)
250 		writel(temp, lpi2c_imx->base + LPI2C_MCCR1);
251 	else
252 		writel(temp, lpi2c_imx->base + LPI2C_MCCR0);
253 
254 	return 0;
255 }
256 
257 static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
258 {
259 	unsigned int temp;
260 	int ret;
261 
262 	ret = pm_runtime_resume_and_get(lpi2c_imx->adapter.dev.parent);
263 	if (ret < 0)
264 		return ret;
265 
266 	temp = MCR_RST;
267 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
268 	writel(0, lpi2c_imx->base + LPI2C_MCR);
269 
270 	ret = lpi2c_imx_config(lpi2c_imx);
271 	if (ret)
272 		goto rpm_put;
273 
274 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
275 	temp |= MCR_MEN;
276 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
277 
278 	return 0;
279 
280 rpm_put:
281 	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
282 	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
283 
284 	return ret;
285 }
286 
287 static int lpi2c_imx_master_disable(struct lpi2c_imx_struct *lpi2c_imx)
288 {
289 	u32 temp;
290 
291 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
292 	temp &= ~MCR_MEN;
293 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
294 
295 	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
296 	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
297 
298 	return 0;
299 }
300 
301 static int lpi2c_imx_msg_complete(struct lpi2c_imx_struct *lpi2c_imx)
302 {
303 	unsigned long timeout;
304 
305 	timeout = wait_for_completion_timeout(&lpi2c_imx->complete, HZ);
306 
307 	return timeout ? 0 : -ETIMEDOUT;
308 }
309 
310 static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct *lpi2c_imx)
311 {
312 	unsigned long orig_jiffies = jiffies;
313 	u32 txcnt;
314 
315 	do {
316 		txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
317 
318 		if (readl(lpi2c_imx->base + LPI2C_MSR) & MSR_NDF) {
319 			dev_dbg(&lpi2c_imx->adapter.dev, "NDF detected\n");
320 			return -EIO;
321 		}
322 
323 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
324 			dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n");
325 			return -ETIMEDOUT;
326 		}
327 		schedule();
328 
329 	} while (txcnt);
330 
331 	return 0;
332 }
333 
334 static void lpi2c_imx_set_tx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
335 {
336 	writel(lpi2c_imx->txfifosize >> 1, lpi2c_imx->base + LPI2C_MFCR);
337 }
338 
339 static void lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
340 {
341 	unsigned int temp, remaining;
342 
343 	remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
344 
345 	if (remaining > (lpi2c_imx->rxfifosize >> 1))
346 		temp = lpi2c_imx->rxfifosize >> 1;
347 	else
348 		temp = 0;
349 
350 	writel(temp << 16, lpi2c_imx->base + LPI2C_MFCR);
351 }
352 
353 static void lpi2c_imx_write_txfifo(struct lpi2c_imx_struct *lpi2c_imx)
354 {
355 	unsigned int data, txcnt;
356 
357 	txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
358 
359 	while (txcnt < lpi2c_imx->txfifosize) {
360 		if (lpi2c_imx->delivered == lpi2c_imx->msglen)
361 			break;
362 
363 		data = lpi2c_imx->tx_buf[lpi2c_imx->delivered++];
364 		writel(data, lpi2c_imx->base + LPI2C_MTDR);
365 		txcnt++;
366 	}
367 
368 	if (lpi2c_imx->delivered < lpi2c_imx->msglen)
369 		lpi2c_imx_intctrl(lpi2c_imx, MIER_TDIE | MIER_NDIE);
370 	else
371 		complete(&lpi2c_imx->complete);
372 }
373 
374 static void lpi2c_imx_read_rxfifo(struct lpi2c_imx_struct *lpi2c_imx)
375 {
376 	unsigned int blocklen, remaining;
377 	unsigned int temp, data;
378 
379 	do {
380 		data = readl(lpi2c_imx->base + LPI2C_MRDR);
381 		if (data & MRDR_RXEMPTY)
382 			break;
383 
384 		lpi2c_imx->rx_buf[lpi2c_imx->delivered++] = data & 0xff;
385 	} while (1);
386 
387 	/*
388 	 * First byte is the length of remaining packet in the SMBus block
389 	 * data read. Add it to msgs->len.
390 	 */
391 	if (lpi2c_imx->block_data) {
392 		blocklen = lpi2c_imx->rx_buf[0];
393 		lpi2c_imx->msglen += blocklen;
394 	}
395 
396 	remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
397 
398 	if (!remaining) {
399 		complete(&lpi2c_imx->complete);
400 		return;
401 	}
402 
403 	/* not finished, still waiting for rx data */
404 	lpi2c_imx_set_rx_watermark(lpi2c_imx);
405 
406 	/* multiple receive commands */
407 	if (lpi2c_imx->block_data) {
408 		lpi2c_imx->block_data = 0;
409 		temp = remaining;
410 		temp |= (RECV_DATA << 8);
411 		writel(temp, lpi2c_imx->base + LPI2C_MTDR);
412 	} else if (!(lpi2c_imx->delivered & 0xff)) {
413 		temp = (remaining > CHUNK_DATA ? CHUNK_DATA : remaining) - 1;
414 		temp |= (RECV_DATA << 8);
415 		writel(temp, lpi2c_imx->base + LPI2C_MTDR);
416 	}
417 
418 	lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE);
419 }
420 
421 static void lpi2c_imx_write(struct lpi2c_imx_struct *lpi2c_imx,
422 			    struct i2c_msg *msgs)
423 {
424 	lpi2c_imx->tx_buf = msgs->buf;
425 	lpi2c_imx_set_tx_watermark(lpi2c_imx);
426 	lpi2c_imx_write_txfifo(lpi2c_imx);
427 }
428 
429 static void lpi2c_imx_read(struct lpi2c_imx_struct *lpi2c_imx,
430 			   struct i2c_msg *msgs)
431 {
432 	unsigned int temp;
433 
434 	lpi2c_imx->rx_buf = msgs->buf;
435 	lpi2c_imx->block_data = msgs->flags & I2C_M_RECV_LEN;
436 
437 	lpi2c_imx_set_rx_watermark(lpi2c_imx);
438 	temp = msgs->len > CHUNK_DATA ? CHUNK_DATA - 1 : msgs->len - 1;
439 	temp |= (RECV_DATA << 8);
440 	writel(temp, lpi2c_imx->base + LPI2C_MTDR);
441 
442 	lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE | MIER_NDIE);
443 }
444 
445 static int lpi2c_imx_xfer(struct i2c_adapter *adapter,
446 			  struct i2c_msg *msgs, int num)
447 {
448 	struct lpi2c_imx_struct *lpi2c_imx = i2c_get_adapdata(adapter);
449 	unsigned int temp;
450 	int i, result;
451 
452 	result = lpi2c_imx_master_enable(lpi2c_imx);
453 	if (result)
454 		return result;
455 
456 	for (i = 0; i < num; i++) {
457 		result = lpi2c_imx_start(lpi2c_imx, &msgs[i]);
458 		if (result)
459 			goto disable;
460 
461 		/* quick smbus */
462 		if (num == 1 && msgs[0].len == 0)
463 			goto stop;
464 
465 		lpi2c_imx->rx_buf = NULL;
466 		lpi2c_imx->tx_buf = NULL;
467 		lpi2c_imx->delivered = 0;
468 		lpi2c_imx->msglen = msgs[i].len;
469 		init_completion(&lpi2c_imx->complete);
470 
471 		if (msgs[i].flags & I2C_M_RD)
472 			lpi2c_imx_read(lpi2c_imx, &msgs[i]);
473 		else
474 			lpi2c_imx_write(lpi2c_imx, &msgs[i]);
475 
476 		result = lpi2c_imx_msg_complete(lpi2c_imx);
477 		if (result)
478 			goto stop;
479 
480 		if (!(msgs[i].flags & I2C_M_RD)) {
481 			result = lpi2c_imx_txfifo_empty(lpi2c_imx);
482 			if (result)
483 				goto stop;
484 		}
485 	}
486 
487 stop:
488 	lpi2c_imx_stop(lpi2c_imx);
489 
490 	temp = readl(lpi2c_imx->base + LPI2C_MSR);
491 	if ((temp & MSR_NDF) && !result)
492 		result = -EIO;
493 
494 disable:
495 	lpi2c_imx_master_disable(lpi2c_imx);
496 
497 	dev_dbg(&lpi2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
498 		(result < 0) ? "error" : "success msg",
499 		(result < 0) ? result : num);
500 
501 	return (result < 0) ? result : num;
502 }
503 
504 static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id)
505 {
506 	struct lpi2c_imx_struct *lpi2c_imx = dev_id;
507 	unsigned int enabled;
508 	unsigned int temp;
509 
510 	enabled = readl(lpi2c_imx->base + LPI2C_MIER);
511 
512 	lpi2c_imx_intctrl(lpi2c_imx, 0);
513 	temp = readl(lpi2c_imx->base + LPI2C_MSR);
514 	temp &= enabled;
515 
516 	if (temp & MSR_NDF)
517 		complete(&lpi2c_imx->complete);
518 	else if (temp & MSR_RDF)
519 		lpi2c_imx_read_rxfifo(lpi2c_imx);
520 	else if (temp & MSR_TDF)
521 		lpi2c_imx_write_txfifo(lpi2c_imx);
522 
523 	return IRQ_HANDLED;
524 }
525 
526 static u32 lpi2c_imx_func(struct i2c_adapter *adapter)
527 {
528 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
529 		I2C_FUNC_SMBUS_READ_BLOCK_DATA;
530 }
531 
532 static const struct i2c_algorithm lpi2c_imx_algo = {
533 	.master_xfer	= lpi2c_imx_xfer,
534 	.functionality	= lpi2c_imx_func,
535 };
536 
537 static const struct of_device_id lpi2c_imx_of_match[] = {
538 	{ .compatible = "fsl,imx7ulp-lpi2c" },
539 	{ },
540 };
541 MODULE_DEVICE_TABLE(of, lpi2c_imx_of_match);
542 
543 static int lpi2c_imx_probe(struct platform_device *pdev)
544 {
545 	struct lpi2c_imx_struct *lpi2c_imx;
546 	unsigned int temp;
547 	int irq, ret;
548 
549 	lpi2c_imx = devm_kzalloc(&pdev->dev, sizeof(*lpi2c_imx), GFP_KERNEL);
550 	if (!lpi2c_imx)
551 		return -ENOMEM;
552 
553 	lpi2c_imx->base = devm_platform_ioremap_resource(pdev, 0);
554 	if (IS_ERR(lpi2c_imx->base))
555 		return PTR_ERR(lpi2c_imx->base);
556 
557 	irq = platform_get_irq(pdev, 0);
558 	if (irq < 0)
559 		return irq;
560 
561 	lpi2c_imx->adapter.owner	= THIS_MODULE;
562 	lpi2c_imx->adapter.algo		= &lpi2c_imx_algo;
563 	lpi2c_imx->adapter.dev.parent	= &pdev->dev;
564 	lpi2c_imx->adapter.dev.of_node	= pdev->dev.of_node;
565 	strscpy(lpi2c_imx->adapter.name, pdev->name,
566 		sizeof(lpi2c_imx->adapter.name));
567 
568 	ret = devm_clk_bulk_get_all(&pdev->dev, &lpi2c_imx->clks);
569 	if (ret < 0)
570 		return dev_err_probe(&pdev->dev, ret, "can't get I2C peripheral clock\n");
571 	lpi2c_imx->num_clks = ret;
572 
573 	ret = of_property_read_u32(pdev->dev.of_node,
574 				   "clock-frequency", &lpi2c_imx->bitrate);
575 	if (ret)
576 		lpi2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ;
577 
578 	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, 0,
579 			       pdev->name, lpi2c_imx);
580 	if (ret)
581 		return dev_err_probe(&pdev->dev, ret, "can't claim irq %d\n", irq);
582 
583 	i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx);
584 	platform_set_drvdata(pdev, lpi2c_imx);
585 
586 	ret = clk_bulk_prepare_enable(lpi2c_imx->num_clks, lpi2c_imx->clks);
587 	if (ret)
588 		return ret;
589 
590 	pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
591 	pm_runtime_use_autosuspend(&pdev->dev);
592 	pm_runtime_get_noresume(&pdev->dev);
593 	pm_runtime_set_active(&pdev->dev);
594 	pm_runtime_enable(&pdev->dev);
595 
596 	temp = readl(lpi2c_imx->base + LPI2C_PARAM);
597 	lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
598 	lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
599 
600 	ret = i2c_add_adapter(&lpi2c_imx->adapter);
601 	if (ret)
602 		goto rpm_disable;
603 
604 	pm_runtime_mark_last_busy(&pdev->dev);
605 	pm_runtime_put_autosuspend(&pdev->dev);
606 
607 	dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
608 
609 	return 0;
610 
611 rpm_disable:
612 	pm_runtime_put(&pdev->dev);
613 	pm_runtime_disable(&pdev->dev);
614 	pm_runtime_dont_use_autosuspend(&pdev->dev);
615 
616 	return ret;
617 }
618 
619 static void lpi2c_imx_remove(struct platform_device *pdev)
620 {
621 	struct lpi2c_imx_struct *lpi2c_imx = platform_get_drvdata(pdev);
622 
623 	i2c_del_adapter(&lpi2c_imx->adapter);
624 
625 	pm_runtime_disable(&pdev->dev);
626 	pm_runtime_dont_use_autosuspend(&pdev->dev);
627 }
628 
629 static int __maybe_unused lpi2c_runtime_suspend(struct device *dev)
630 {
631 	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
632 
633 	clk_bulk_disable(lpi2c_imx->num_clks, lpi2c_imx->clks);
634 	pinctrl_pm_select_sleep_state(dev);
635 
636 	return 0;
637 }
638 
639 static int __maybe_unused lpi2c_runtime_resume(struct device *dev)
640 {
641 	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
642 	int ret;
643 
644 	pinctrl_pm_select_default_state(dev);
645 	ret = clk_bulk_enable(lpi2c_imx->num_clks, lpi2c_imx->clks);
646 	if (ret) {
647 		dev_err(dev, "failed to enable I2C clock, ret=%d\n", ret);
648 		return ret;
649 	}
650 
651 	return 0;
652 }
653 
654 static const struct dev_pm_ops lpi2c_pm_ops = {
655 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
656 				      pm_runtime_force_resume)
657 	SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,
658 			   lpi2c_runtime_resume, NULL)
659 };
660 
661 static struct platform_driver lpi2c_imx_driver = {
662 	.probe = lpi2c_imx_probe,
663 	.remove_new = lpi2c_imx_remove,
664 	.driver = {
665 		.name = DRIVER_NAME,
666 		.of_match_table = lpi2c_imx_of_match,
667 		.pm = &lpi2c_pm_ops,
668 	},
669 };
670 
671 module_platform_driver(lpi2c_imx_driver);
672 
673 MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
674 MODULE_DESCRIPTION("I2C adapter driver for LPI2C bus");
675 MODULE_LICENSE("GPL");
676