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 
lpi2c_imx_intctrl(struct lpi2c_imx_struct * lpi2c_imx,unsigned int enable)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 
lpi2c_imx_bus_busy(struct lpi2c_imx_struct * lpi2c_imx)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 
lpi2c_imx_set_mode(struct lpi2c_imx_struct * lpi2c_imx)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 
lpi2c_imx_start(struct lpi2c_imx_struct * lpi2c_imx,struct i2c_msg * msgs)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 
lpi2c_imx_stop(struct lpi2c_imx_struct * lpi2c_imx)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 */
lpi2c_imx_config(struct lpi2c_imx_struct * lpi2c_imx)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 (!clk_rate)
212 		return -EINVAL;
213 
214 	if (lpi2c_imx->mode == HS || lpi2c_imx->mode == ULTRA_FAST)
215 		filt = 0;
216 	else
217 		filt = 2;
218 
219 	for (prescale = 0; prescale <= 7; prescale++) {
220 		clk_cycle = clk_rate / ((1 << prescale) * lpi2c_imx->bitrate)
221 			    - 3 - (filt >> 1);
222 		clkhi = DIV_ROUND_UP(clk_cycle, I2C_CLK_RATIO + 1);
223 		clklo = clk_cycle - clkhi;
224 		if (clklo < 64)
225 			break;
226 	}
227 
228 	if (prescale > 7)
229 		return -EINVAL;
230 
231 	/* set MCFGR1: PINCFG, PRESCALE, IGNACK */
232 	if (lpi2c_imx->mode == ULTRA_FAST)
233 		pincfg = TWO_PIN_OO;
234 	else
235 		pincfg = TWO_PIN_OD;
236 	temp = prescale | pincfg << 24;
237 
238 	if (lpi2c_imx->mode == ULTRA_FAST)
239 		temp |= MCFGR1_IGNACK;
240 
241 	writel(temp, lpi2c_imx->base + LPI2C_MCFGR1);
242 
243 	/* set MCFGR2: FILTSDA, FILTSCL */
244 	temp = (filt << 16) | (filt << 24);
245 	writel(temp, lpi2c_imx->base + LPI2C_MCFGR2);
246 
247 	/* set MCCR: DATAVD, SETHOLD, CLKHI, CLKLO */
248 	sethold = clkhi;
249 	datavd = clkhi >> 1;
250 	temp = datavd << 24 | sethold << 16 | clkhi << 8 | clklo;
251 
252 	if (lpi2c_imx->mode == HS)
253 		writel(temp, lpi2c_imx->base + LPI2C_MCCR1);
254 	else
255 		writel(temp, lpi2c_imx->base + LPI2C_MCCR0);
256 
257 	return 0;
258 }
259 
lpi2c_imx_master_enable(struct lpi2c_imx_struct * lpi2c_imx)260 static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
261 {
262 	unsigned int temp;
263 	int ret;
264 
265 	ret = pm_runtime_resume_and_get(lpi2c_imx->adapter.dev.parent);
266 	if (ret < 0)
267 		return ret;
268 
269 	temp = MCR_RST;
270 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
271 	writel(0, lpi2c_imx->base + LPI2C_MCR);
272 
273 	ret = lpi2c_imx_config(lpi2c_imx);
274 	if (ret)
275 		goto rpm_put;
276 
277 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
278 	temp |= MCR_MEN;
279 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
280 
281 	return 0;
282 
283 rpm_put:
284 	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
285 	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
286 
287 	return ret;
288 }
289 
lpi2c_imx_master_disable(struct lpi2c_imx_struct * lpi2c_imx)290 static int lpi2c_imx_master_disable(struct lpi2c_imx_struct *lpi2c_imx)
291 {
292 	u32 temp;
293 
294 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
295 	temp &= ~MCR_MEN;
296 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
297 
298 	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
299 	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
300 
301 	return 0;
302 }
303 
lpi2c_imx_msg_complete(struct lpi2c_imx_struct * lpi2c_imx)304 static int lpi2c_imx_msg_complete(struct lpi2c_imx_struct *lpi2c_imx)
305 {
306 	unsigned long timeout;
307 
308 	timeout = wait_for_completion_timeout(&lpi2c_imx->complete, HZ);
309 
310 	return timeout ? 0 : -ETIMEDOUT;
311 }
312 
lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct * lpi2c_imx)313 static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct *lpi2c_imx)
314 {
315 	unsigned long orig_jiffies = jiffies;
316 	u32 txcnt;
317 
318 	do {
319 		txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
320 
321 		if (readl(lpi2c_imx->base + LPI2C_MSR) & MSR_NDF) {
322 			dev_dbg(&lpi2c_imx->adapter.dev, "NDF detected\n");
323 			return -EIO;
324 		}
325 
326 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
327 			dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n");
328 			return -ETIMEDOUT;
329 		}
330 		schedule();
331 
332 	} while (txcnt);
333 
334 	return 0;
335 }
336 
lpi2c_imx_set_tx_watermark(struct lpi2c_imx_struct * lpi2c_imx)337 static void lpi2c_imx_set_tx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
338 {
339 	writel(lpi2c_imx->txfifosize >> 1, lpi2c_imx->base + LPI2C_MFCR);
340 }
341 
lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct * lpi2c_imx)342 static void lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
343 {
344 	unsigned int temp, remaining;
345 
346 	remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
347 
348 	if (remaining > (lpi2c_imx->rxfifosize >> 1))
349 		temp = lpi2c_imx->rxfifosize >> 1;
350 	else
351 		temp = 0;
352 
353 	writel(temp << 16, lpi2c_imx->base + LPI2C_MFCR);
354 }
355 
lpi2c_imx_write_txfifo(struct lpi2c_imx_struct * lpi2c_imx)356 static void lpi2c_imx_write_txfifo(struct lpi2c_imx_struct *lpi2c_imx)
357 {
358 	unsigned int data, txcnt;
359 
360 	txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
361 
362 	while (txcnt < lpi2c_imx->txfifosize) {
363 		if (lpi2c_imx->delivered == lpi2c_imx->msglen)
364 			break;
365 
366 		data = lpi2c_imx->tx_buf[lpi2c_imx->delivered++];
367 		writel(data, lpi2c_imx->base + LPI2C_MTDR);
368 		txcnt++;
369 	}
370 
371 	if (lpi2c_imx->delivered < lpi2c_imx->msglen)
372 		lpi2c_imx_intctrl(lpi2c_imx, MIER_TDIE | MIER_NDIE);
373 	else
374 		complete(&lpi2c_imx->complete);
375 }
376 
lpi2c_imx_read_rxfifo(struct lpi2c_imx_struct * lpi2c_imx)377 static void lpi2c_imx_read_rxfifo(struct lpi2c_imx_struct *lpi2c_imx)
378 {
379 	unsigned int blocklen, remaining;
380 	unsigned int temp, data;
381 
382 	do {
383 		data = readl(lpi2c_imx->base + LPI2C_MRDR);
384 		if (data & MRDR_RXEMPTY)
385 			break;
386 
387 		lpi2c_imx->rx_buf[lpi2c_imx->delivered++] = data & 0xff;
388 	} while (1);
389 
390 	/*
391 	 * First byte is the length of remaining packet in the SMBus block
392 	 * data read. Add it to msgs->len.
393 	 */
394 	if (lpi2c_imx->block_data) {
395 		blocklen = lpi2c_imx->rx_buf[0];
396 		lpi2c_imx->msglen += blocklen;
397 	}
398 
399 	remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
400 
401 	if (!remaining) {
402 		complete(&lpi2c_imx->complete);
403 		return;
404 	}
405 
406 	/* not finished, still waiting for rx data */
407 	lpi2c_imx_set_rx_watermark(lpi2c_imx);
408 
409 	/* multiple receive commands */
410 	if (lpi2c_imx->block_data) {
411 		lpi2c_imx->block_data = 0;
412 		temp = remaining;
413 		temp |= (RECV_DATA << 8);
414 		writel(temp, lpi2c_imx->base + LPI2C_MTDR);
415 	} else if (!(lpi2c_imx->delivered & 0xff)) {
416 		temp = (remaining > CHUNK_DATA ? CHUNK_DATA : remaining) - 1;
417 		temp |= (RECV_DATA << 8);
418 		writel(temp, lpi2c_imx->base + LPI2C_MTDR);
419 	}
420 
421 	lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE);
422 }
423 
lpi2c_imx_write(struct lpi2c_imx_struct * lpi2c_imx,struct i2c_msg * msgs)424 static void lpi2c_imx_write(struct lpi2c_imx_struct *lpi2c_imx,
425 			    struct i2c_msg *msgs)
426 {
427 	lpi2c_imx->tx_buf = msgs->buf;
428 	lpi2c_imx_set_tx_watermark(lpi2c_imx);
429 	lpi2c_imx_write_txfifo(lpi2c_imx);
430 }
431 
lpi2c_imx_read(struct lpi2c_imx_struct * lpi2c_imx,struct i2c_msg * msgs)432 static void lpi2c_imx_read(struct lpi2c_imx_struct *lpi2c_imx,
433 			   struct i2c_msg *msgs)
434 {
435 	unsigned int temp;
436 
437 	lpi2c_imx->rx_buf = msgs->buf;
438 	lpi2c_imx->block_data = msgs->flags & I2C_M_RECV_LEN;
439 
440 	lpi2c_imx_set_rx_watermark(lpi2c_imx);
441 	temp = msgs->len > CHUNK_DATA ? CHUNK_DATA - 1 : msgs->len - 1;
442 	temp |= (RECV_DATA << 8);
443 	writel(temp, lpi2c_imx->base + LPI2C_MTDR);
444 
445 	lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE | MIER_NDIE);
446 }
447 
lpi2c_imx_xfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)448 static int lpi2c_imx_xfer(struct i2c_adapter *adapter,
449 			  struct i2c_msg *msgs, int num)
450 {
451 	struct lpi2c_imx_struct *lpi2c_imx = i2c_get_adapdata(adapter);
452 	unsigned int temp;
453 	int i, result;
454 
455 	result = lpi2c_imx_master_enable(lpi2c_imx);
456 	if (result)
457 		return result;
458 
459 	for (i = 0; i < num; i++) {
460 		result = lpi2c_imx_start(lpi2c_imx, &msgs[i]);
461 		if (result)
462 			goto disable;
463 
464 		/* quick smbus */
465 		if (num == 1 && msgs[0].len == 0)
466 			goto stop;
467 
468 		lpi2c_imx->rx_buf = NULL;
469 		lpi2c_imx->tx_buf = NULL;
470 		lpi2c_imx->delivered = 0;
471 		lpi2c_imx->msglen = msgs[i].len;
472 		init_completion(&lpi2c_imx->complete);
473 
474 		if (msgs[i].flags & I2C_M_RD)
475 			lpi2c_imx_read(lpi2c_imx, &msgs[i]);
476 		else
477 			lpi2c_imx_write(lpi2c_imx, &msgs[i]);
478 
479 		result = lpi2c_imx_msg_complete(lpi2c_imx);
480 		if (result)
481 			goto stop;
482 
483 		if (!(msgs[i].flags & I2C_M_RD)) {
484 			result = lpi2c_imx_txfifo_empty(lpi2c_imx);
485 			if (result)
486 				goto stop;
487 		}
488 	}
489 
490 stop:
491 	lpi2c_imx_stop(lpi2c_imx);
492 
493 	temp = readl(lpi2c_imx->base + LPI2C_MSR);
494 	if ((temp & MSR_NDF) && !result)
495 		result = -EIO;
496 
497 disable:
498 	lpi2c_imx_master_disable(lpi2c_imx);
499 
500 	dev_dbg(&lpi2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
501 		(result < 0) ? "error" : "success msg",
502 		(result < 0) ? result : num);
503 
504 	return (result < 0) ? result : num;
505 }
506 
lpi2c_imx_isr(int irq,void * dev_id)507 static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id)
508 {
509 	struct lpi2c_imx_struct *lpi2c_imx = dev_id;
510 	unsigned int enabled;
511 	unsigned int temp;
512 
513 	enabled = readl(lpi2c_imx->base + LPI2C_MIER);
514 
515 	lpi2c_imx_intctrl(lpi2c_imx, 0);
516 	temp = readl(lpi2c_imx->base + LPI2C_MSR);
517 	temp &= enabled;
518 
519 	if (temp & MSR_NDF)
520 		complete(&lpi2c_imx->complete);
521 	else if (temp & MSR_RDF)
522 		lpi2c_imx_read_rxfifo(lpi2c_imx);
523 	else if (temp & MSR_TDF)
524 		lpi2c_imx_write_txfifo(lpi2c_imx);
525 
526 	return IRQ_HANDLED;
527 }
528 
lpi2c_imx_func(struct i2c_adapter * adapter)529 static u32 lpi2c_imx_func(struct i2c_adapter *adapter)
530 {
531 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
532 		I2C_FUNC_SMBUS_READ_BLOCK_DATA;
533 }
534 
535 static const struct i2c_algorithm lpi2c_imx_algo = {
536 	.master_xfer	= lpi2c_imx_xfer,
537 	.functionality	= lpi2c_imx_func,
538 };
539 
540 static const struct of_device_id lpi2c_imx_of_match[] = {
541 	{ .compatible = "fsl,imx7ulp-lpi2c" },
542 	{ },
543 };
544 MODULE_DEVICE_TABLE(of, lpi2c_imx_of_match);
545 
lpi2c_imx_probe(struct platform_device * pdev)546 static int lpi2c_imx_probe(struct platform_device *pdev)
547 {
548 	struct lpi2c_imx_struct *lpi2c_imx;
549 	unsigned int temp;
550 	int irq, ret;
551 
552 	lpi2c_imx = devm_kzalloc(&pdev->dev, sizeof(*lpi2c_imx), GFP_KERNEL);
553 	if (!lpi2c_imx)
554 		return -ENOMEM;
555 
556 	lpi2c_imx->base = devm_platform_ioremap_resource(pdev, 0);
557 	if (IS_ERR(lpi2c_imx->base))
558 		return PTR_ERR(lpi2c_imx->base);
559 
560 	irq = platform_get_irq(pdev, 0);
561 	if (irq < 0)
562 		return irq;
563 
564 	lpi2c_imx->adapter.owner	= THIS_MODULE;
565 	lpi2c_imx->adapter.algo		= &lpi2c_imx_algo;
566 	lpi2c_imx->adapter.dev.parent	= &pdev->dev;
567 	lpi2c_imx->adapter.dev.of_node	= pdev->dev.of_node;
568 	strscpy(lpi2c_imx->adapter.name, pdev->name,
569 		sizeof(lpi2c_imx->adapter.name));
570 
571 	ret = devm_clk_bulk_get_all(&pdev->dev, &lpi2c_imx->clks);
572 	if (ret < 0)
573 		return dev_err_probe(&pdev->dev, ret, "can't get I2C peripheral clock\n");
574 	lpi2c_imx->num_clks = ret;
575 
576 	ret = of_property_read_u32(pdev->dev.of_node,
577 				   "clock-frequency", &lpi2c_imx->bitrate);
578 	if (ret)
579 		lpi2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ;
580 
581 	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, 0,
582 			       pdev->name, lpi2c_imx);
583 	if (ret)
584 		return dev_err_probe(&pdev->dev, ret, "can't claim irq %d\n", irq);
585 
586 	i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx);
587 	platform_set_drvdata(pdev, lpi2c_imx);
588 
589 	ret = clk_bulk_prepare_enable(lpi2c_imx->num_clks, lpi2c_imx->clks);
590 	if (ret)
591 		return ret;
592 
593 	pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
594 	pm_runtime_use_autosuspend(&pdev->dev);
595 	pm_runtime_get_noresume(&pdev->dev);
596 	pm_runtime_set_active(&pdev->dev);
597 	pm_runtime_enable(&pdev->dev);
598 
599 	temp = readl(lpi2c_imx->base + LPI2C_PARAM);
600 	lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
601 	lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
602 
603 	ret = i2c_add_adapter(&lpi2c_imx->adapter);
604 	if (ret)
605 		goto rpm_disable;
606 
607 	pm_runtime_mark_last_busy(&pdev->dev);
608 	pm_runtime_put_autosuspend(&pdev->dev);
609 
610 	dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
611 
612 	return 0;
613 
614 rpm_disable:
615 	pm_runtime_put(&pdev->dev);
616 	pm_runtime_disable(&pdev->dev);
617 	pm_runtime_dont_use_autosuspend(&pdev->dev);
618 
619 	return ret;
620 }
621 
lpi2c_imx_remove(struct platform_device * pdev)622 static void lpi2c_imx_remove(struct platform_device *pdev)
623 {
624 	struct lpi2c_imx_struct *lpi2c_imx = platform_get_drvdata(pdev);
625 
626 	i2c_del_adapter(&lpi2c_imx->adapter);
627 
628 	pm_runtime_disable(&pdev->dev);
629 	pm_runtime_dont_use_autosuspend(&pdev->dev);
630 }
631 
lpi2c_runtime_suspend(struct device * dev)632 static int __maybe_unused lpi2c_runtime_suspend(struct device *dev)
633 {
634 	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
635 
636 	clk_bulk_disable(lpi2c_imx->num_clks, lpi2c_imx->clks);
637 	pinctrl_pm_select_sleep_state(dev);
638 
639 	return 0;
640 }
641 
lpi2c_runtime_resume(struct device * dev)642 static int __maybe_unused lpi2c_runtime_resume(struct device *dev)
643 {
644 	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
645 	int ret;
646 
647 	pinctrl_pm_select_default_state(dev);
648 	ret = clk_bulk_enable(lpi2c_imx->num_clks, lpi2c_imx->clks);
649 	if (ret) {
650 		dev_err(dev, "failed to enable I2C clock, ret=%d\n", ret);
651 		return ret;
652 	}
653 
654 	return 0;
655 }
656 
657 static const struct dev_pm_ops lpi2c_pm_ops = {
658 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
659 				      pm_runtime_force_resume)
660 	SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,
661 			   lpi2c_runtime_resume, NULL)
662 };
663 
664 static struct platform_driver lpi2c_imx_driver = {
665 	.probe = lpi2c_imx_probe,
666 	.remove_new = lpi2c_imx_remove,
667 	.driver = {
668 		.name = DRIVER_NAME,
669 		.of_match_table = lpi2c_imx_of_match,
670 		.pm = &lpi2c_pm_ops,
671 	},
672 };
673 
674 module_platform_driver(lpi2c_imx_driver);
675 
676 MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
677 MODULE_DESCRIPTION("I2C adapter driver for LPI2C bus");
678 MODULE_LICENSE("GPL");
679