xref: /openbmc/linux/drivers/i2c/busses/i2c-sprd.c (revision 5a244f48)
1 /*
2  * Copyright (C) 2017 Spreadtrum Communications Inc.
3  *
4  * SPDX-License-Identifier: (GPL-2.0+ OR MIT)
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/delay.h>
9 #include <linux/err.h>
10 #include <linux/io.h>
11 #include <linux/i2c.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/platform_device.h>
18 #include <linux/pm_runtime.h>
19 
20 #define I2C_CTL			0x00
21 #define I2C_ADDR_CFG		0x04
22 #define I2C_COUNT		0x08
23 #define I2C_RX			0x0c
24 #define I2C_TX			0x10
25 #define I2C_STATUS		0x14
26 #define I2C_HSMODE_CFG		0x18
27 #define I2C_VERSION		0x1c
28 #define ADDR_DVD0		0x20
29 #define ADDR_DVD1		0x24
30 #define ADDR_STA0_DVD		0x28
31 #define ADDR_RST		0x2c
32 
33 /* I2C_CTL */
34 #define STP_EN			BIT(20)
35 #define FIFO_AF_LVL_MASK	GENMASK(19, 16)
36 #define FIFO_AF_LVL		16
37 #define FIFO_AE_LVL_MASK	GENMASK(15, 12)
38 #define FIFO_AE_LVL		12
39 #define I2C_DMA_EN		BIT(11)
40 #define FULL_INTEN		BIT(10)
41 #define EMPTY_INTEN		BIT(9)
42 #define I2C_DVD_OPT		BIT(8)
43 #define I2C_OUT_OPT		BIT(7)
44 #define I2C_TRIM_OPT		BIT(6)
45 #define I2C_HS_MODE		BIT(4)
46 #define I2C_MODE		BIT(3)
47 #define I2C_EN			BIT(2)
48 #define I2C_INT_EN		BIT(1)
49 #define I2C_START		BIT(0)
50 
51 /* I2C_STATUS */
52 #define SDA_IN			BIT(21)
53 #define SCL_IN			BIT(20)
54 #define FIFO_FULL		BIT(4)
55 #define FIFO_EMPTY		BIT(3)
56 #define I2C_INT			BIT(2)
57 #define I2C_RX_ACK		BIT(1)
58 #define I2C_BUSY		BIT(0)
59 
60 /* ADDR_RST */
61 #define I2C_RST			BIT(0)
62 
63 #define I2C_FIFO_DEEP		12
64 #define I2C_FIFO_FULL_THLD	15
65 #define I2C_FIFO_EMPTY_THLD	4
66 #define I2C_DATA_STEP		8
67 #define I2C_ADDR_DVD0_CALC(high, low)	\
68 	((((high) & GENMASK(15, 0)) << 16) | ((low) & GENMASK(15, 0)))
69 #define I2C_ADDR_DVD1_CALC(high, low)	\
70 	(((high) & GENMASK(31, 16)) | (((low) & GENMASK(31, 16)) >> 16))
71 
72 /* timeout (ms) for pm runtime autosuspend */
73 #define SPRD_I2C_PM_TIMEOUT	1000
74 
75 /* SPRD i2c data structure */
76 struct sprd_i2c {
77 	struct i2c_adapter adap;
78 	struct device *dev;
79 	void __iomem *base;
80 	struct i2c_msg *msg;
81 	struct clk *clk;
82 	u32 src_clk;
83 	u32 bus_freq;
84 	struct completion complete;
85 	u8 *buf;
86 	u32 count;
87 	int irq;
88 	int err;
89 };
90 
91 static void sprd_i2c_set_count(struct sprd_i2c *i2c_dev, u32 count)
92 {
93 	writel(count, i2c_dev->base + I2C_COUNT);
94 }
95 
96 static void sprd_i2c_send_stop(struct sprd_i2c *i2c_dev, int stop)
97 {
98 	u32 tmp = readl(i2c_dev->base + I2C_CTL);
99 
100 	if (stop)
101 		writel(tmp & ~STP_EN, i2c_dev->base + I2C_CTL);
102 	else
103 		writel(tmp | STP_EN, i2c_dev->base + I2C_CTL);
104 }
105 
106 static void sprd_i2c_clear_start(struct sprd_i2c *i2c_dev)
107 {
108 	u32 tmp = readl(i2c_dev->base + I2C_CTL);
109 
110 	writel(tmp & ~I2C_START, i2c_dev->base + I2C_CTL);
111 }
112 
113 static void sprd_i2c_clear_ack(struct sprd_i2c *i2c_dev)
114 {
115 	u32 tmp = readl(i2c_dev->base + I2C_STATUS);
116 
117 	writel(tmp & ~I2C_RX_ACK, i2c_dev->base + I2C_STATUS);
118 }
119 
120 static void sprd_i2c_clear_irq(struct sprd_i2c *i2c_dev)
121 {
122 	u32 tmp = readl(i2c_dev->base + I2C_STATUS);
123 
124 	writel(tmp & ~I2C_INT, i2c_dev->base + I2C_STATUS);
125 }
126 
127 static void sprd_i2c_reset_fifo(struct sprd_i2c *i2c_dev)
128 {
129 	writel(I2C_RST, i2c_dev->base + ADDR_RST);
130 }
131 
132 static void sprd_i2c_set_devaddr(struct sprd_i2c *i2c_dev, struct i2c_msg *m)
133 {
134 	writel(m->addr << 1, i2c_dev->base + I2C_ADDR_CFG);
135 }
136 
137 static void sprd_i2c_write_bytes(struct sprd_i2c *i2c_dev, u8 *buf, u32 len)
138 {
139 	u32 i;
140 
141 	for (i = 0; i < len; i++)
142 		writeb(buf[i], i2c_dev->base + I2C_TX);
143 }
144 
145 static void sprd_i2c_read_bytes(struct sprd_i2c *i2c_dev, u8 *buf, u32 len)
146 {
147 	u32 i;
148 
149 	for (i = 0; i < len; i++)
150 		buf[i] = readb(i2c_dev->base + I2C_RX);
151 }
152 
153 static void sprd_i2c_set_full_thld(struct sprd_i2c *i2c_dev, u32 full_thld)
154 {
155 	u32 tmp = readl(i2c_dev->base + I2C_CTL);
156 
157 	tmp &= ~FIFO_AF_LVL_MASK;
158 	tmp |= full_thld << FIFO_AF_LVL;
159 	writel(tmp, i2c_dev->base + I2C_CTL);
160 };
161 
162 static void sprd_i2c_set_empty_thld(struct sprd_i2c *i2c_dev, u32 empty_thld)
163 {
164 	u32 tmp = readl(i2c_dev->base + I2C_CTL);
165 
166 	tmp &= ~FIFO_AE_LVL_MASK;
167 	tmp |= empty_thld << FIFO_AE_LVL;
168 	writel(tmp, i2c_dev->base + I2C_CTL);
169 };
170 
171 static void sprd_i2c_set_fifo_full_int(struct sprd_i2c *i2c_dev, int enable)
172 {
173 	u32 tmp = readl(i2c_dev->base + I2C_CTL);
174 
175 	if (enable)
176 		tmp |= FULL_INTEN;
177 	else
178 		tmp &= ~FULL_INTEN;
179 
180 	writel(tmp, i2c_dev->base + I2C_CTL);
181 };
182 
183 static void sprd_i2c_set_fifo_empty_int(struct sprd_i2c *i2c_dev, int enable)
184 {
185 	u32 tmp = readl(i2c_dev->base + I2C_CTL);
186 
187 	if (enable)
188 		tmp |= EMPTY_INTEN;
189 	else
190 		tmp &= ~EMPTY_INTEN;
191 
192 	writel(tmp, i2c_dev->base + I2C_CTL);
193 };
194 
195 static void sprd_i2c_opt_start(struct sprd_i2c *i2c_dev)
196 {
197 	u32 tmp = readl(i2c_dev->base + I2C_CTL);
198 
199 	writel(tmp | I2C_START, i2c_dev->base + I2C_CTL);
200 }
201 
202 static void sprd_i2c_opt_mode(struct sprd_i2c *i2c_dev, int rw)
203 {
204 	u32 cmd = readl(i2c_dev->base + I2C_CTL) & ~I2C_MODE;
205 
206 	writel(cmd | rw << 3, i2c_dev->base + I2C_CTL);
207 }
208 
209 static void sprd_i2c_data_transfer(struct sprd_i2c *i2c_dev)
210 {
211 	u32 i2c_count = i2c_dev->count;
212 	u32 need_tran = i2c_count <= I2C_FIFO_DEEP ? i2c_count : I2C_FIFO_DEEP;
213 	struct i2c_msg *msg = i2c_dev->msg;
214 
215 	if (msg->flags & I2C_M_RD) {
216 		sprd_i2c_read_bytes(i2c_dev, i2c_dev->buf, I2C_FIFO_FULL_THLD);
217 		i2c_dev->count -= I2C_FIFO_FULL_THLD;
218 		i2c_dev->buf += I2C_FIFO_FULL_THLD;
219 
220 		/*
221 		 * If the read data count is larger than rx fifo full threshold,
222 		 * we should enable the rx fifo full interrupt to read data
223 		 * again.
224 		 */
225 		if (i2c_dev->count >= I2C_FIFO_FULL_THLD)
226 			sprd_i2c_set_fifo_full_int(i2c_dev, 1);
227 	} else {
228 		sprd_i2c_write_bytes(i2c_dev, i2c_dev->buf, need_tran);
229 		i2c_dev->buf += need_tran;
230 		i2c_dev->count -= need_tran;
231 
232 		/*
233 		 * If the write data count is arger than tx fifo depth which
234 		 * means we can not write all data in one time, then we should
235 		 * enable the tx fifo empty interrupt to write again.
236 		 */
237 		if (i2c_count > I2C_FIFO_DEEP)
238 			sprd_i2c_set_fifo_empty_int(i2c_dev, 1);
239 	}
240 }
241 
242 static int sprd_i2c_handle_msg(struct i2c_adapter *i2c_adap,
243 			       struct i2c_msg *msg, bool is_last_msg)
244 {
245 	struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
246 
247 	i2c_dev->msg = msg;
248 	i2c_dev->buf = msg->buf;
249 	i2c_dev->count = msg->len;
250 
251 	reinit_completion(&i2c_dev->complete);
252 	sprd_i2c_reset_fifo(i2c_dev);
253 	sprd_i2c_set_devaddr(i2c_dev, msg);
254 	sprd_i2c_set_count(i2c_dev, msg->len);
255 
256 	if (msg->flags & I2C_M_RD) {
257 		sprd_i2c_opt_mode(i2c_dev, 1);
258 		sprd_i2c_send_stop(i2c_dev, 1);
259 	} else {
260 		sprd_i2c_opt_mode(i2c_dev, 0);
261 		sprd_i2c_send_stop(i2c_dev, !!is_last_msg);
262 	}
263 
264 	/*
265 	 * We should enable rx fifo full interrupt to get data when receiving
266 	 * full data.
267 	 */
268 	if (msg->flags & I2C_M_RD)
269 		sprd_i2c_set_fifo_full_int(i2c_dev, 1);
270 	else
271 		sprd_i2c_data_transfer(i2c_dev);
272 
273 	sprd_i2c_opt_start(i2c_dev);
274 
275 	wait_for_completion(&i2c_dev->complete);
276 
277 	return i2c_dev->err;
278 }
279 
280 static int sprd_i2c_master_xfer(struct i2c_adapter *i2c_adap,
281 				struct i2c_msg *msgs, int num)
282 {
283 	struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
284 	int im, ret;
285 
286 	ret = pm_runtime_get_sync(i2c_dev->dev);
287 	if (ret < 0)
288 		return ret;
289 
290 	for (im = 0; im < num - 1; im++) {
291 		ret = sprd_i2c_handle_msg(i2c_adap, &msgs[im], 0);
292 		if (ret)
293 			goto err_msg;
294 	}
295 
296 	ret = sprd_i2c_handle_msg(i2c_adap, &msgs[im++], 1);
297 
298 err_msg:
299 	pm_runtime_mark_last_busy(i2c_dev->dev);
300 	pm_runtime_put_autosuspend(i2c_dev->dev);
301 
302 	return ret < 0 ? ret : im;
303 }
304 
305 static u32 sprd_i2c_func(struct i2c_adapter *adap)
306 {
307 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
308 }
309 
310 static const struct i2c_algorithm sprd_i2c_algo = {
311 	.master_xfer = sprd_i2c_master_xfer,
312 	.functionality = sprd_i2c_func,
313 };
314 
315 static void sprd_i2c_set_clk(struct sprd_i2c *i2c_dev, u32 freq)
316 {
317 	u32 apb_clk = i2c_dev->src_clk;
318 	/*
319 	 * From I2C databook, the prescale calculation formula:
320 	 * prescale = freq_i2c / (4 * freq_scl) - 1;
321 	 */
322 	u32 i2c_dvd = apb_clk / (4 * freq) - 1;
323 	/*
324 	 * From I2C databook, the high period of SCL clock is recommended as
325 	 * 40% (2/5), and the low period of SCL clock is recommended as 60%
326 	 * (3/5), then the formula should be:
327 	 * high = (prescale * 2 * 2) / 5
328 	 * low = (prescale * 2 * 3) / 5
329 	 */
330 	u32 high = ((i2c_dvd << 1) * 2) / 5;
331 	u32 low = ((i2c_dvd << 1) * 3) / 5;
332 	u32 div0 = I2C_ADDR_DVD0_CALC(high, low);
333 	u32 div1 = I2C_ADDR_DVD1_CALC(high, low);
334 
335 	writel(div0, i2c_dev->base + ADDR_DVD0);
336 	writel(div1, i2c_dev->base + ADDR_DVD1);
337 
338 	/* Start hold timing = hold time(us) * source clock */
339 	if (freq == 400000)
340 		writel((6 * apb_clk) / 10000000, i2c_dev->base + ADDR_STA0_DVD);
341 	else if (freq == 100000)
342 		writel((4 * apb_clk) / 1000000, i2c_dev->base + ADDR_STA0_DVD);
343 }
344 
345 static void sprd_i2c_enable(struct sprd_i2c *i2c_dev)
346 {
347 	u32 tmp = I2C_DVD_OPT;
348 
349 	writel(tmp, i2c_dev->base + I2C_CTL);
350 
351 	sprd_i2c_set_full_thld(i2c_dev, I2C_FIFO_FULL_THLD);
352 	sprd_i2c_set_empty_thld(i2c_dev, I2C_FIFO_EMPTY_THLD);
353 
354 	sprd_i2c_set_clk(i2c_dev, i2c_dev->bus_freq);
355 	sprd_i2c_reset_fifo(i2c_dev);
356 	sprd_i2c_clear_irq(i2c_dev);
357 
358 	tmp = readl(i2c_dev->base + I2C_CTL);
359 	writel(tmp | I2C_EN | I2C_INT_EN, i2c_dev->base + I2C_CTL);
360 }
361 
362 static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id)
363 {
364 	struct sprd_i2c *i2c_dev = dev_id;
365 	struct i2c_msg *msg = i2c_dev->msg;
366 	bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
367 	u32 i2c_count = readl(i2c_dev->base + I2C_COUNT);
368 	u32 i2c_tran;
369 
370 	if (msg->flags & I2C_M_RD)
371 		i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
372 	else
373 		i2c_tran = i2c_count;
374 
375 	/*
376 	 * If we got one ACK from slave when writing data, and we did not
377 	 * finish this transmission (i2c_tran is not zero), then we should
378 	 * continue to write data.
379 	 *
380 	 * For reading data, ack is always true, if i2c_tran is not 0 which
381 	 * means we still need to contine to read data from slave.
382 	 */
383 	if (i2c_tran && ack) {
384 		sprd_i2c_data_transfer(i2c_dev);
385 		return IRQ_HANDLED;
386 	}
387 
388 	i2c_dev->err = 0;
389 
390 	/*
391 	 * If we did not get one ACK from slave when writing data, we should
392 	 * return -EIO to notify users.
393 	 */
394 	if (!ack)
395 		i2c_dev->err = -EIO;
396 	else if (msg->flags & I2C_M_RD && i2c_dev->count)
397 		sprd_i2c_read_bytes(i2c_dev, i2c_dev->buf, i2c_dev->count);
398 
399 	/* Transmission is done and clear ack and start operation */
400 	sprd_i2c_clear_ack(i2c_dev);
401 	sprd_i2c_clear_start(i2c_dev);
402 	complete(&i2c_dev->complete);
403 
404 	return IRQ_HANDLED;
405 }
406 
407 static irqreturn_t sprd_i2c_isr(int irq, void *dev_id)
408 {
409 	struct sprd_i2c *i2c_dev = dev_id;
410 	struct i2c_msg *msg = i2c_dev->msg;
411 	u32 i2c_count = readl(i2c_dev->base + I2C_COUNT);
412 	bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
413 	u32 i2c_tran;
414 
415 	if (msg->flags & I2C_M_RD)
416 		i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
417 	else
418 		i2c_tran = i2c_count;
419 
420 	/*
421 	 * If we did not get one ACK from slave when writing data, then we
422 	 * should finish this transmission since we got some errors.
423 	 *
424 	 * When writing data, if i2c_tran == 0 which means we have writen
425 	 * done all data, then we can finish this transmission.
426 	 *
427 	 * When reading data, if conut < rx fifo full threshold, which
428 	 * means we can read all data in one time, then we can finish this
429 	 * transmission too.
430 	 */
431 	if (!i2c_tran || !ack) {
432 		sprd_i2c_clear_start(i2c_dev);
433 		sprd_i2c_clear_irq(i2c_dev);
434 	}
435 
436 	sprd_i2c_set_fifo_empty_int(i2c_dev, 0);
437 	sprd_i2c_set_fifo_full_int(i2c_dev, 0);
438 
439 	return IRQ_WAKE_THREAD;
440 }
441 
442 static int sprd_i2c_clk_init(struct sprd_i2c *i2c_dev)
443 {
444 	struct clk *clk_i2c, *clk_parent;
445 
446 	clk_i2c = devm_clk_get(i2c_dev->dev, "i2c");
447 	if (IS_ERR(clk_i2c)) {
448 		dev_warn(i2c_dev->dev, "i2c%d can't get the i2c clock\n",
449 			 i2c_dev->adap.nr);
450 		clk_i2c = NULL;
451 	}
452 
453 	clk_parent = devm_clk_get(i2c_dev->dev, "source");
454 	if (IS_ERR(clk_parent)) {
455 		dev_warn(i2c_dev->dev, "i2c%d can't get the source clock\n",
456 			 i2c_dev->adap.nr);
457 		clk_parent = NULL;
458 	}
459 
460 	if (clk_set_parent(clk_i2c, clk_parent))
461 		i2c_dev->src_clk = clk_get_rate(clk_i2c);
462 	else
463 		i2c_dev->src_clk = 26000000;
464 
465 	dev_dbg(i2c_dev->dev, "i2c%d set source clock is %d\n",
466 		i2c_dev->adap.nr, i2c_dev->src_clk);
467 
468 	i2c_dev->clk = devm_clk_get(i2c_dev->dev, "enable");
469 	if (IS_ERR(i2c_dev->clk)) {
470 		dev_warn(i2c_dev->dev, "i2c%d can't get the enable clock\n",
471 			 i2c_dev->adap.nr);
472 		i2c_dev->clk = NULL;
473 	}
474 
475 	return 0;
476 }
477 
478 static int sprd_i2c_probe(struct platform_device *pdev)
479 {
480 	struct device *dev = &pdev->dev;
481 	struct sprd_i2c *i2c_dev;
482 	struct resource *res;
483 	u32 prop;
484 	int ret;
485 
486 	pdev->id = of_alias_get_id(dev->of_node, "i2c");
487 
488 	i2c_dev = devm_kzalloc(dev, sizeof(struct sprd_i2c), GFP_KERNEL);
489 	if (!i2c_dev)
490 		return -ENOMEM;
491 
492 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
493 	i2c_dev->base = devm_ioremap_resource(dev, res);
494 	if (IS_ERR(i2c_dev->base))
495 		return PTR_ERR(i2c_dev->base);
496 
497 	i2c_dev->irq = platform_get_irq(pdev, 0);
498 	if (i2c_dev->irq < 0) {
499 		dev_err(&pdev->dev, "failed to get irq resource\n");
500 		return i2c_dev->irq;
501 	}
502 
503 	i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
504 	init_completion(&i2c_dev->complete);
505 	snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),
506 		 "%s", "sprd-i2c");
507 
508 	i2c_dev->bus_freq = 100000;
509 	i2c_dev->adap.owner = THIS_MODULE;
510 	i2c_dev->dev = dev;
511 	i2c_dev->adap.retries = 3;
512 	i2c_dev->adap.algo = &sprd_i2c_algo;
513 	i2c_dev->adap.algo_data = i2c_dev;
514 	i2c_dev->adap.dev.parent = dev;
515 	i2c_dev->adap.nr = pdev->id;
516 	i2c_dev->adap.dev.of_node = dev->of_node;
517 
518 	if (!of_property_read_u32(dev->of_node, "clock-frequency", &prop))
519 		i2c_dev->bus_freq = prop;
520 
521 	/* We only support 100k and 400k now, otherwise will return error. */
522 	if (i2c_dev->bus_freq != 100000 && i2c_dev->bus_freq != 400000)
523 		return -EINVAL;
524 
525 	sprd_i2c_clk_init(i2c_dev);
526 	platform_set_drvdata(pdev, i2c_dev);
527 
528 	ret = clk_prepare_enable(i2c_dev->clk);
529 	if (ret)
530 		return ret;
531 
532 	sprd_i2c_enable(i2c_dev);
533 
534 	pm_runtime_set_autosuspend_delay(i2c_dev->dev, SPRD_I2C_PM_TIMEOUT);
535 	pm_runtime_use_autosuspend(i2c_dev->dev);
536 	pm_runtime_set_active(i2c_dev->dev);
537 	pm_runtime_enable(i2c_dev->dev);
538 
539 	ret = pm_runtime_get_sync(i2c_dev->dev);
540 	if (ret < 0)
541 		goto err_rpm_put;
542 
543 	ret = devm_request_threaded_irq(dev, i2c_dev->irq,
544 		sprd_i2c_isr, sprd_i2c_isr_thread,
545 		IRQF_NO_SUSPEND | IRQF_ONESHOT,
546 		pdev->name, i2c_dev);
547 	if (ret) {
548 		dev_err(&pdev->dev, "failed to request irq %d\n", i2c_dev->irq);
549 		goto err_rpm_put;
550 	}
551 
552 	ret = i2c_add_numbered_adapter(&i2c_dev->adap);
553 	if (ret) {
554 		dev_err(&pdev->dev, "add adapter failed\n");
555 		goto err_rpm_put;
556 	}
557 
558 	pm_runtime_mark_last_busy(i2c_dev->dev);
559 	pm_runtime_put_autosuspend(i2c_dev->dev);
560 	return 0;
561 
562 err_rpm_put:
563 	pm_runtime_put_noidle(i2c_dev->dev);
564 	pm_runtime_disable(i2c_dev->dev);
565 	clk_disable_unprepare(i2c_dev->clk);
566 	return ret;
567 }
568 
569 static int sprd_i2c_remove(struct platform_device *pdev)
570 {
571 	struct sprd_i2c *i2c_dev = platform_get_drvdata(pdev);
572 	int ret;
573 
574 	ret = pm_runtime_get_sync(i2c_dev->dev);
575 	if (ret < 0)
576 		return ret;
577 
578 	i2c_del_adapter(&i2c_dev->adap);
579 	clk_disable_unprepare(i2c_dev->clk);
580 
581 	pm_runtime_put_noidle(i2c_dev->dev);
582 	pm_runtime_disable(i2c_dev->dev);
583 
584 	return 0;
585 }
586 
587 static int __maybe_unused sprd_i2c_suspend_noirq(struct device *pdev)
588 {
589 	return pm_runtime_force_suspend(pdev);
590 }
591 
592 static int __maybe_unused sprd_i2c_resume_noirq(struct device *pdev)
593 {
594 	return pm_runtime_force_resume(pdev);
595 }
596 
597 static int __maybe_unused sprd_i2c_runtime_suspend(struct device *pdev)
598 {
599 	struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
600 
601 	clk_disable_unprepare(i2c_dev->clk);
602 
603 	return 0;
604 }
605 
606 static int __maybe_unused sprd_i2c_runtime_resume(struct device *pdev)
607 {
608 	struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
609 	int ret;
610 
611 	ret = clk_prepare_enable(i2c_dev->clk);
612 	if (ret)
613 		return ret;
614 
615 	sprd_i2c_enable(i2c_dev);
616 
617 	return 0;
618 }
619 
620 static const struct dev_pm_ops sprd_i2c_pm_ops = {
621 	SET_RUNTIME_PM_OPS(sprd_i2c_runtime_suspend,
622 			   sprd_i2c_runtime_resume, NULL)
623 
624 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(sprd_i2c_suspend_noirq,
625 				      sprd_i2c_resume_noirq)
626 };
627 
628 static const struct of_device_id sprd_i2c_of_match[] = {
629 	{ .compatible = "sprd,sc9860-i2c", },
630 	{},
631 };
632 
633 static struct platform_driver sprd_i2c_driver = {
634 	.probe = sprd_i2c_probe,
635 	.remove = sprd_i2c_remove,
636 	.driver = {
637 		   .name = "sprd-i2c",
638 		   .of_match_table = sprd_i2c_of_match,
639 		   .pm = &sprd_i2c_pm_ops,
640 	},
641 };
642 
643 static int sprd_i2c_init(void)
644 {
645 	return platform_driver_register(&sprd_i2c_driver);
646 }
647 arch_initcall_sync(sprd_i2c_init);
648