Loading...
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/module.h>
16#include <linux/of.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/* timeout (ms) for transfer message */
75#define I2C_XFER_TIMEOUT 1000
76
77/* SPRD i2c data structure */
78struct sprd_i2c {
79 struct i2c_adapter adap;
80 struct device *dev;
81 void __iomem *base;
82 struct i2c_msg *msg;
83 struct clk *clk;
84 u32 src_clk;
85 u32 bus_freq;
86 struct completion complete;
87 u8 *buf;
88 u32 count;
89 int irq;
90 int err;
91};
92
93static void sprd_i2c_set_count(struct sprd_i2c *i2c_dev, u32 count)
94{
95 writel(count, i2c_dev->base + I2C_COUNT);
96}
97
98static void sprd_i2c_send_stop(struct sprd_i2c *i2c_dev, int stop)
99{
100 u32 tmp = readl(i2c_dev->base + I2C_CTL);
101
102 if (stop)
103 writel(tmp & ~STP_EN, i2c_dev->base + I2C_CTL);
104 else
105 writel(tmp | STP_EN, i2c_dev->base + I2C_CTL);
106}
107
108static void sprd_i2c_clear_start(struct sprd_i2c *i2c_dev)
109{
110 u32 tmp = readl(i2c_dev->base + I2C_CTL);
111
112 writel(tmp & ~I2C_START, i2c_dev->base + I2C_CTL);
113}
114
115static void sprd_i2c_clear_ack(struct sprd_i2c *i2c_dev)
116{
117 u32 tmp = readl(i2c_dev->base + I2C_STATUS);
118
119 writel(tmp & ~I2C_RX_ACK, i2c_dev->base + I2C_STATUS);
120}
121
122static void sprd_i2c_clear_irq(struct sprd_i2c *i2c_dev)
123{
124 u32 tmp = readl(i2c_dev->base + I2C_STATUS);
125
126 writel(tmp & ~I2C_INT, i2c_dev->base + I2C_STATUS);
127}
128
129static void sprd_i2c_reset_fifo(struct sprd_i2c *i2c_dev)
130{
131 writel(I2C_RST, i2c_dev->base + ADDR_RST);
132}
133
134static void sprd_i2c_set_devaddr(struct sprd_i2c *i2c_dev, struct i2c_msg *m)
135{
136 writel(m->addr << 1, i2c_dev->base + I2C_ADDR_CFG);
137}
138
139static void sprd_i2c_write_bytes(struct sprd_i2c *i2c_dev, u8 *buf, u32 len)
140{
141 u32 i;
142
143 for (i = 0; i < len; i++)
144 writeb(buf[i], i2c_dev->base + I2C_TX);
145}
146
147static void sprd_i2c_read_bytes(struct sprd_i2c *i2c_dev, u8 *buf, u32 len)
148{
149 u32 i;
150
151 for (i = 0; i < len; i++)
152 buf[i] = readb(i2c_dev->base + I2C_RX);
153}
154
155static void sprd_i2c_set_full_thld(struct sprd_i2c *i2c_dev, u32 full_thld)
156{
157 u32 tmp = readl(i2c_dev->base + I2C_CTL);
158
159 tmp &= ~FIFO_AF_LVL_MASK;
160 tmp |= full_thld << FIFO_AF_LVL;
161 writel(tmp, i2c_dev->base + I2C_CTL);
162};
163
164static void sprd_i2c_set_empty_thld(struct sprd_i2c *i2c_dev, u32 empty_thld)
165{
166 u32 tmp = readl(i2c_dev->base + I2C_CTL);
167
168 tmp &= ~FIFO_AE_LVL_MASK;
169 tmp |= empty_thld << FIFO_AE_LVL;
170 writel(tmp, i2c_dev->base + I2C_CTL);
171};
172
173static void sprd_i2c_set_fifo_full_int(struct sprd_i2c *i2c_dev, int enable)
174{
175 u32 tmp = readl(i2c_dev->base + I2C_CTL);
176
177 if (enable)
178 tmp |= FULL_INTEN;
179 else
180 tmp &= ~FULL_INTEN;
181
182 writel(tmp, i2c_dev->base + I2C_CTL);
183};
184
185static void sprd_i2c_set_fifo_empty_int(struct sprd_i2c *i2c_dev, int enable)
186{
187 u32 tmp = readl(i2c_dev->base + I2C_CTL);
188
189 if (enable)
190 tmp |= EMPTY_INTEN;
191 else
192 tmp &= ~EMPTY_INTEN;
193
194 writel(tmp, i2c_dev->base + I2C_CTL);
195};
196
197static void sprd_i2c_opt_start(struct sprd_i2c *i2c_dev)
198{
199 u32 tmp = readl(i2c_dev->base + I2C_CTL);
200
201 writel(tmp | I2C_START, i2c_dev->base + I2C_CTL);
202}
203
204static void sprd_i2c_opt_mode(struct sprd_i2c *i2c_dev, int rw)
205{
206 u32 cmd = readl(i2c_dev->base + I2C_CTL) & ~I2C_MODE;
207
208 writel(cmd | rw << 3, i2c_dev->base + I2C_CTL);
209}
210
211static void sprd_i2c_data_transfer(struct sprd_i2c *i2c_dev)
212{
213 u32 i2c_count = i2c_dev->count;
214 u32 need_tran = i2c_count <= I2C_FIFO_DEEP ? i2c_count : I2C_FIFO_DEEP;
215 struct i2c_msg *msg = i2c_dev->msg;
216
217 if (msg->flags & I2C_M_RD) {
218 sprd_i2c_read_bytes(i2c_dev, i2c_dev->buf, I2C_FIFO_FULL_THLD);
219 i2c_dev->count -= I2C_FIFO_FULL_THLD;
220 i2c_dev->buf += I2C_FIFO_FULL_THLD;
221
222 /*
223 * If the read data count is larger than rx fifo full threshold,
224 * we should enable the rx fifo full interrupt to read data
225 * again.
226 */
227 if (i2c_dev->count >= I2C_FIFO_FULL_THLD)
228 sprd_i2c_set_fifo_full_int(i2c_dev, 1);
229 } else {
230 sprd_i2c_write_bytes(i2c_dev, i2c_dev->buf, need_tran);
231 i2c_dev->buf += need_tran;
232 i2c_dev->count -= need_tran;
233
234 /*
235 * If the write data count is arger than tx fifo depth which
236 * means we can not write all data in one time, then we should
237 * enable the tx fifo empty interrupt to write again.
238 */
239 if (i2c_count > I2C_FIFO_DEEP)
240 sprd_i2c_set_fifo_empty_int(i2c_dev, 1);
241 }
242}
243
244static int sprd_i2c_handle_msg(struct i2c_adapter *i2c_adap,
245 struct i2c_msg *msg, bool is_last_msg)
246{
247 struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
248 unsigned long time_left;
249
250 i2c_dev->msg = msg;
251 i2c_dev->buf = msg->buf;
252 i2c_dev->count = msg->len;
253
254 reinit_completion(&i2c_dev->complete);
255 sprd_i2c_reset_fifo(i2c_dev);
256 sprd_i2c_set_devaddr(i2c_dev, msg);
257 sprd_i2c_set_count(i2c_dev, msg->len);
258
259 if (msg->flags & I2C_M_RD) {
260 sprd_i2c_opt_mode(i2c_dev, 1);
261 sprd_i2c_send_stop(i2c_dev, 1);
262 } else {
263 sprd_i2c_opt_mode(i2c_dev, 0);
264 sprd_i2c_send_stop(i2c_dev, !!is_last_msg);
265 }
266
267 /*
268 * We should enable rx fifo full interrupt to get data when receiving
269 * full data.
270 */
271 if (msg->flags & I2C_M_RD)
272 sprd_i2c_set_fifo_full_int(i2c_dev, 1);
273 else
274 sprd_i2c_data_transfer(i2c_dev);
275
276 sprd_i2c_opt_start(i2c_dev);
277
278 time_left = wait_for_completion_timeout(&i2c_dev->complete,
279 msecs_to_jiffies(I2C_XFER_TIMEOUT));
280 if (!time_left)
281 return -ETIMEDOUT;
282
283 return i2c_dev->err;
284}
285
286static int sprd_i2c_master_xfer(struct i2c_adapter *i2c_adap,
287 struct i2c_msg *msgs, int num)
288{
289 struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
290 int im, ret;
291
292 ret = pm_runtime_resume_and_get(i2c_dev->dev);
293 if (ret < 0)
294 return ret;
295
296 for (im = 0; im < num - 1; im++) {
297 ret = sprd_i2c_handle_msg(i2c_adap, &msgs[im], 0);
298 if (ret)
299 goto err_msg;
300 }
301
302 ret = sprd_i2c_handle_msg(i2c_adap, &msgs[im++], 1);
303
304err_msg:
305 pm_runtime_mark_last_busy(i2c_dev->dev);
306 pm_runtime_put_autosuspend(i2c_dev->dev);
307
308 return ret < 0 ? ret : im;
309}
310
311static u32 sprd_i2c_func(struct i2c_adapter *adap)
312{
313 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
314}
315
316static const struct i2c_algorithm sprd_i2c_algo = {
317 .master_xfer = sprd_i2c_master_xfer,
318 .functionality = sprd_i2c_func,
319};
320
321static void sprd_i2c_set_clk(struct sprd_i2c *i2c_dev, u32 freq)
322{
323 u32 apb_clk = i2c_dev->src_clk;
324 /*
325 * From I2C databook, the prescale calculation formula:
326 * prescale = freq_i2c / (4 * freq_scl) - 1;
327 */
328 u32 i2c_dvd = apb_clk / (4 * freq) - 1;
329 /*
330 * From I2C databook, the high period of SCL clock is recommended as
331 * 40% (2/5), and the low period of SCL clock is recommended as 60%
332 * (3/5), then the formula should be:
333 * high = (prescale * 2 * 2) / 5
334 * low = (prescale * 2 * 3) / 5
335 */
336 u32 high = ((i2c_dvd << 1) * 2) / 5;
337 u32 low = ((i2c_dvd << 1) * 3) / 5;
338 u32 div0 = I2C_ADDR_DVD0_CALC(high, low);
339 u32 div1 = I2C_ADDR_DVD1_CALC(high, low);
340
341 writel(div0, i2c_dev->base + ADDR_DVD0);
342 writel(div1, i2c_dev->base + ADDR_DVD1);
343
344 /* Start hold timing = hold time(us) * source clock */
345 if (freq == I2C_MAX_FAST_MODE_FREQ)
346 writel((6 * apb_clk) / 10000000, i2c_dev->base + ADDR_STA0_DVD);
347 else if (freq == I2C_MAX_STANDARD_MODE_FREQ)
348 writel((4 * apb_clk) / 1000000, i2c_dev->base + ADDR_STA0_DVD);
349}
350
351static void sprd_i2c_enable(struct sprd_i2c *i2c_dev)
352{
353 u32 tmp = I2C_DVD_OPT;
354
355 writel(tmp, i2c_dev->base + I2C_CTL);
356
357 sprd_i2c_set_full_thld(i2c_dev, I2C_FIFO_FULL_THLD);
358 sprd_i2c_set_empty_thld(i2c_dev, I2C_FIFO_EMPTY_THLD);
359
360 sprd_i2c_set_clk(i2c_dev, i2c_dev->bus_freq);
361 sprd_i2c_reset_fifo(i2c_dev);
362 sprd_i2c_clear_irq(i2c_dev);
363
364 tmp = readl(i2c_dev->base + I2C_CTL);
365 writel(tmp | I2C_EN | I2C_INT_EN, i2c_dev->base + I2C_CTL);
366}
367
368static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id)
369{
370 struct sprd_i2c *i2c_dev = dev_id;
371 struct i2c_msg *msg = i2c_dev->msg;
372 bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
373 u32 i2c_tran;
374
375 if (msg->flags & I2C_M_RD)
376 i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
377 else
378 i2c_tran = i2c_dev->count;
379
380 /*
381 * If we got one ACK from slave when writing data, and we did not
382 * finish this transmission (i2c_tran is not zero), then we should
383 * continue to write data.
384 *
385 * For reading data, ack is always true, if i2c_tran is not 0 which
386 * means we still need to contine to read data from slave.
387 */
388 if (i2c_tran && ack) {
389 sprd_i2c_data_transfer(i2c_dev);
390 return IRQ_HANDLED;
391 }
392
393 i2c_dev->err = 0;
394
395 /*
396 * If we did not get one ACK from slave when writing data, we should
397 * return -EIO to notify users.
398 */
399 if (!ack)
400 i2c_dev->err = -EIO;
401 else if (msg->flags & I2C_M_RD && i2c_dev->count)
402 sprd_i2c_read_bytes(i2c_dev, i2c_dev->buf, i2c_dev->count);
403
404 /* Transmission is done and clear ack and start operation */
405 sprd_i2c_clear_ack(i2c_dev);
406 sprd_i2c_clear_start(i2c_dev);
407 complete(&i2c_dev->complete);
408
409 return IRQ_HANDLED;
410}
411
412static irqreturn_t sprd_i2c_isr(int irq, void *dev_id)
413{
414 struct sprd_i2c *i2c_dev = dev_id;
415 struct i2c_msg *msg = i2c_dev->msg;
416 bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
417 u32 i2c_tran;
418
419 if (msg->flags & I2C_M_RD)
420 i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
421 else
422 i2c_tran = i2c_dev->count;
423
424 /*
425 * If we did not get one ACK from slave when writing data, then we
426 * should finish this transmission since we got some errors.
427 *
428 * When writing data, if i2c_tran == 0 which means we have writen
429 * done all data, then we can finish this transmission.
430 *
431 * When reading data, if conut < rx fifo full threshold, which
432 * means we can read all data in one time, then we can finish this
433 * transmission too.
434 */
435 if (!i2c_tran || !ack) {
436 sprd_i2c_clear_start(i2c_dev);
437 sprd_i2c_clear_irq(i2c_dev);
438 }
439
440 sprd_i2c_set_fifo_empty_int(i2c_dev, 0);
441 sprd_i2c_set_fifo_full_int(i2c_dev, 0);
442
443 return IRQ_WAKE_THREAD;
444}
445
446static int sprd_i2c_clk_init(struct sprd_i2c *i2c_dev)
447{
448 struct clk *clk_i2c, *clk_parent;
449
450 clk_i2c = devm_clk_get(i2c_dev->dev, "i2c");
451 if (IS_ERR(clk_i2c)) {
452 dev_warn(i2c_dev->dev, "i2c%d can't get the i2c clock\n",
453 i2c_dev->adap.nr);
454 clk_i2c = NULL;
455 }
456
457 clk_parent = devm_clk_get(i2c_dev->dev, "source");
458 if (IS_ERR(clk_parent)) {
459 dev_warn(i2c_dev->dev, "i2c%d can't get the source clock\n",
460 i2c_dev->adap.nr);
461 clk_parent = NULL;
462 }
463
464 if (clk_set_parent(clk_i2c, clk_parent))
465 i2c_dev->src_clk = clk_get_rate(clk_i2c);
466 else
467 i2c_dev->src_clk = 26000000;
468
469 dev_dbg(i2c_dev->dev, "i2c%d set source clock is %d\n",
470 i2c_dev->adap.nr, i2c_dev->src_clk);
471
472 i2c_dev->clk = devm_clk_get(i2c_dev->dev, "enable");
473 if (IS_ERR(i2c_dev->clk)) {
474 dev_err(i2c_dev->dev, "i2c%d can't get the enable clock\n",
475 i2c_dev->adap.nr);
476 return PTR_ERR(i2c_dev->clk);
477 }
478
479 return 0;
480}
481
482static int sprd_i2c_probe(struct platform_device *pdev)
483{
484 struct device *dev = &pdev->dev;
485 struct sprd_i2c *i2c_dev;
486 u32 prop;
487 int ret;
488
489 pdev->id = of_alias_get_id(dev->of_node, "i2c");
490
491 i2c_dev = devm_kzalloc(dev, sizeof(struct sprd_i2c), GFP_KERNEL);
492 if (!i2c_dev)
493 return -ENOMEM;
494
495 i2c_dev->base = devm_platform_ioremap_resource(pdev, 0);
496 if (IS_ERR(i2c_dev->base))
497 return PTR_ERR(i2c_dev->base);
498
499 i2c_dev->irq = platform_get_irq(pdev, 0);
500 if (i2c_dev->irq < 0)
501 return i2c_dev->irq;
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 = I2C_MAX_STANDARD_MODE_FREQ;
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 != I2C_MAX_STANDARD_MODE_FREQ &&
523 i2c_dev->bus_freq != I2C_MAX_FAST_MODE_FREQ)
524 return -EINVAL;
525
526 ret = sprd_i2c_clk_init(i2c_dev);
527 if (ret)
528 return ret;
529
530 platform_set_drvdata(pdev, i2c_dev);
531
532 ret = clk_prepare_enable(i2c_dev->clk);
533 if (ret)
534 return ret;
535
536 sprd_i2c_enable(i2c_dev);
537
538 pm_runtime_set_autosuspend_delay(i2c_dev->dev, SPRD_I2C_PM_TIMEOUT);
539 pm_runtime_use_autosuspend(i2c_dev->dev);
540 pm_runtime_set_active(i2c_dev->dev);
541 pm_runtime_enable(i2c_dev->dev);
542
543 ret = pm_runtime_get_sync(i2c_dev->dev);
544 if (ret < 0)
545 goto err_rpm_put;
546
547 ret = devm_request_threaded_irq(dev, i2c_dev->irq,
548 sprd_i2c_isr, sprd_i2c_isr_thread,
549 IRQF_NO_SUSPEND | IRQF_ONESHOT,
550 pdev->name, i2c_dev);
551 if (ret) {
552 dev_err(&pdev->dev, "failed to request irq %d\n", i2c_dev->irq);
553 goto err_rpm_put;
554 }
555
556 ret = i2c_add_numbered_adapter(&i2c_dev->adap);
557 if (ret) {
558 dev_err(&pdev->dev, "add adapter failed\n");
559 goto err_rpm_put;
560 }
561
562 pm_runtime_mark_last_busy(i2c_dev->dev);
563 pm_runtime_put_autosuspend(i2c_dev->dev);
564 return 0;
565
566err_rpm_put:
567 pm_runtime_put_noidle(i2c_dev->dev);
568 pm_runtime_disable(i2c_dev->dev);
569 clk_disable_unprepare(i2c_dev->clk);
570 return ret;
571}
572
573static int sprd_i2c_remove(struct platform_device *pdev)
574{
575 struct sprd_i2c *i2c_dev = platform_get_drvdata(pdev);
576 int ret;
577
578 ret = pm_runtime_get_sync(i2c_dev->dev);
579 if (ret < 0)
580 dev_err(&pdev->dev, "Failed to resume device (%pe)\n", ERR_PTR(ret));
581
582 i2c_del_adapter(&i2c_dev->adap);
583
584 if (ret >= 0)
585 clk_disable_unprepare(i2c_dev->clk);
586
587 pm_runtime_put_noidle(i2c_dev->dev);
588 pm_runtime_disable(i2c_dev->dev);
589
590 return 0;
591}
592
593static int __maybe_unused sprd_i2c_suspend_noirq(struct device *dev)
594{
595 struct sprd_i2c *i2c_dev = dev_get_drvdata(dev);
596
597 i2c_mark_adapter_suspended(&i2c_dev->adap);
598 return pm_runtime_force_suspend(dev);
599}
600
601static int __maybe_unused sprd_i2c_resume_noirq(struct device *dev)
602{
603 struct sprd_i2c *i2c_dev = dev_get_drvdata(dev);
604
605 i2c_mark_adapter_resumed(&i2c_dev->adap);
606 return pm_runtime_force_resume(dev);
607}
608
609static int __maybe_unused sprd_i2c_runtime_suspend(struct device *dev)
610{
611 struct sprd_i2c *i2c_dev = dev_get_drvdata(dev);
612
613 clk_disable_unprepare(i2c_dev->clk);
614
615 return 0;
616}
617
618static int __maybe_unused sprd_i2c_runtime_resume(struct device *dev)
619{
620 struct sprd_i2c *i2c_dev = dev_get_drvdata(dev);
621 int ret;
622
623 ret = clk_prepare_enable(i2c_dev->clk);
624 if (ret)
625 return ret;
626
627 sprd_i2c_enable(i2c_dev);
628
629 return 0;
630}
631
632static const struct dev_pm_ops sprd_i2c_pm_ops = {
633 SET_RUNTIME_PM_OPS(sprd_i2c_runtime_suspend,
634 sprd_i2c_runtime_resume, NULL)
635
636 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(sprd_i2c_suspend_noirq,
637 sprd_i2c_resume_noirq)
638};
639
640static const struct of_device_id sprd_i2c_of_match[] = {
641 { .compatible = "sprd,sc9860-i2c", },
642 {},
643};
644MODULE_DEVICE_TABLE(of, sprd_i2c_of_match);
645
646static struct platform_driver sprd_i2c_driver = {
647 .probe = sprd_i2c_probe,
648 .remove = sprd_i2c_remove,
649 .driver = {
650 .name = "sprd-i2c",
651 .of_match_table = sprd_i2c_of_match,
652 .pm = &sprd_i2c_pm_ops,
653 },
654};
655
656module_platform_driver(sprd_i2c_driver);
657
658MODULE_DESCRIPTION("Spreadtrum I2C master controller driver");
659MODULE_LICENSE("GPL v2");
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/module.h>
16#include <linux/of.h>
17#include <linux/of_device.h>
18#include <linux/platform_device.h>
19#include <linux/pm_runtime.h>
20
21#define I2C_CTL 0x00
22#define I2C_ADDR_CFG 0x04
23#define I2C_COUNT 0x08
24#define I2C_RX 0x0c
25#define I2C_TX 0x10
26#define I2C_STATUS 0x14
27#define I2C_HSMODE_CFG 0x18
28#define I2C_VERSION 0x1c
29#define ADDR_DVD0 0x20
30#define ADDR_DVD1 0x24
31#define ADDR_STA0_DVD 0x28
32#define ADDR_RST 0x2c
33
34/* I2C_CTL */
35#define STP_EN BIT(20)
36#define FIFO_AF_LVL_MASK GENMASK(19, 16)
37#define FIFO_AF_LVL 16
38#define FIFO_AE_LVL_MASK GENMASK(15, 12)
39#define FIFO_AE_LVL 12
40#define I2C_DMA_EN BIT(11)
41#define FULL_INTEN BIT(10)
42#define EMPTY_INTEN BIT(9)
43#define I2C_DVD_OPT BIT(8)
44#define I2C_OUT_OPT BIT(7)
45#define I2C_TRIM_OPT BIT(6)
46#define I2C_HS_MODE BIT(4)
47#define I2C_MODE BIT(3)
48#define I2C_EN BIT(2)
49#define I2C_INT_EN BIT(1)
50#define I2C_START BIT(0)
51
52/* I2C_STATUS */
53#define SDA_IN BIT(21)
54#define SCL_IN BIT(20)
55#define FIFO_FULL BIT(4)
56#define FIFO_EMPTY BIT(3)
57#define I2C_INT BIT(2)
58#define I2C_RX_ACK BIT(1)
59#define I2C_BUSY BIT(0)
60
61/* ADDR_RST */
62#define I2C_RST BIT(0)
63
64#define I2C_FIFO_DEEP 12
65#define I2C_FIFO_FULL_THLD 15
66#define I2C_FIFO_EMPTY_THLD 4
67#define I2C_DATA_STEP 8
68#define I2C_ADDR_DVD0_CALC(high, low) \
69 ((((high) & GENMASK(15, 0)) << 16) | ((low) & GENMASK(15, 0)))
70#define I2C_ADDR_DVD1_CALC(high, low) \
71 (((high) & GENMASK(31, 16)) | (((low) & GENMASK(31, 16)) >> 16))
72
73/* timeout (ms) for pm runtime autosuspend */
74#define SPRD_I2C_PM_TIMEOUT 1000
75
76/* SPRD i2c data structure */
77struct sprd_i2c {
78 struct i2c_adapter adap;
79 struct device *dev;
80 void __iomem *base;
81 struct i2c_msg *msg;
82 struct clk *clk;
83 u32 src_clk;
84 u32 bus_freq;
85 struct completion complete;
86 u8 *buf;
87 u32 count;
88 int irq;
89 int err;
90};
91
92static void sprd_i2c_set_count(struct sprd_i2c *i2c_dev, u32 count)
93{
94 writel(count, i2c_dev->base + I2C_COUNT);
95}
96
97static void sprd_i2c_send_stop(struct sprd_i2c *i2c_dev, int stop)
98{
99 u32 tmp = readl(i2c_dev->base + I2C_CTL);
100
101 if (stop)
102 writel(tmp & ~STP_EN, i2c_dev->base + I2C_CTL);
103 else
104 writel(tmp | STP_EN, i2c_dev->base + I2C_CTL);
105}
106
107static void sprd_i2c_clear_start(struct sprd_i2c *i2c_dev)
108{
109 u32 tmp = readl(i2c_dev->base + I2C_CTL);
110
111 writel(tmp & ~I2C_START, i2c_dev->base + I2C_CTL);
112}
113
114static void sprd_i2c_clear_ack(struct sprd_i2c *i2c_dev)
115{
116 u32 tmp = readl(i2c_dev->base + I2C_STATUS);
117
118 writel(tmp & ~I2C_RX_ACK, i2c_dev->base + I2C_STATUS);
119}
120
121static void sprd_i2c_clear_irq(struct sprd_i2c *i2c_dev)
122{
123 u32 tmp = readl(i2c_dev->base + I2C_STATUS);
124
125 writel(tmp & ~I2C_INT, i2c_dev->base + I2C_STATUS);
126}
127
128static void sprd_i2c_reset_fifo(struct sprd_i2c *i2c_dev)
129{
130 writel(I2C_RST, i2c_dev->base + ADDR_RST);
131}
132
133static void sprd_i2c_set_devaddr(struct sprd_i2c *i2c_dev, struct i2c_msg *m)
134{
135 writel(m->addr << 1, i2c_dev->base + I2C_ADDR_CFG);
136}
137
138static void sprd_i2c_write_bytes(struct sprd_i2c *i2c_dev, u8 *buf, u32 len)
139{
140 u32 i;
141
142 for (i = 0; i < len; i++)
143 writeb(buf[i], i2c_dev->base + I2C_TX);
144}
145
146static void sprd_i2c_read_bytes(struct sprd_i2c *i2c_dev, u8 *buf, u32 len)
147{
148 u32 i;
149
150 for (i = 0; i < len; i++)
151 buf[i] = readb(i2c_dev->base + I2C_RX);
152}
153
154static void sprd_i2c_set_full_thld(struct sprd_i2c *i2c_dev, u32 full_thld)
155{
156 u32 tmp = readl(i2c_dev->base + I2C_CTL);
157
158 tmp &= ~FIFO_AF_LVL_MASK;
159 tmp |= full_thld << FIFO_AF_LVL;
160 writel(tmp, i2c_dev->base + I2C_CTL);
161};
162
163static void sprd_i2c_set_empty_thld(struct sprd_i2c *i2c_dev, u32 empty_thld)
164{
165 u32 tmp = readl(i2c_dev->base + I2C_CTL);
166
167 tmp &= ~FIFO_AE_LVL_MASK;
168 tmp |= empty_thld << FIFO_AE_LVL;
169 writel(tmp, i2c_dev->base + I2C_CTL);
170};
171
172static void sprd_i2c_set_fifo_full_int(struct sprd_i2c *i2c_dev, int enable)
173{
174 u32 tmp = readl(i2c_dev->base + I2C_CTL);
175
176 if (enable)
177 tmp |= FULL_INTEN;
178 else
179 tmp &= ~FULL_INTEN;
180
181 writel(tmp, i2c_dev->base + I2C_CTL);
182};
183
184static void sprd_i2c_set_fifo_empty_int(struct sprd_i2c *i2c_dev, int enable)
185{
186 u32 tmp = readl(i2c_dev->base + I2C_CTL);
187
188 if (enable)
189 tmp |= EMPTY_INTEN;
190 else
191 tmp &= ~EMPTY_INTEN;
192
193 writel(tmp, i2c_dev->base + I2C_CTL);
194};
195
196static void sprd_i2c_opt_start(struct sprd_i2c *i2c_dev)
197{
198 u32 tmp = readl(i2c_dev->base + I2C_CTL);
199
200 writel(tmp | I2C_START, i2c_dev->base + I2C_CTL);
201}
202
203static void sprd_i2c_opt_mode(struct sprd_i2c *i2c_dev, int rw)
204{
205 u32 cmd = readl(i2c_dev->base + I2C_CTL) & ~I2C_MODE;
206
207 writel(cmd | rw << 3, i2c_dev->base + I2C_CTL);
208}
209
210static void sprd_i2c_data_transfer(struct sprd_i2c *i2c_dev)
211{
212 u32 i2c_count = i2c_dev->count;
213 u32 need_tran = i2c_count <= I2C_FIFO_DEEP ? i2c_count : I2C_FIFO_DEEP;
214 struct i2c_msg *msg = i2c_dev->msg;
215
216 if (msg->flags & I2C_M_RD) {
217 sprd_i2c_read_bytes(i2c_dev, i2c_dev->buf, I2C_FIFO_FULL_THLD);
218 i2c_dev->count -= I2C_FIFO_FULL_THLD;
219 i2c_dev->buf += I2C_FIFO_FULL_THLD;
220
221 /*
222 * If the read data count is larger than rx fifo full threshold,
223 * we should enable the rx fifo full interrupt to read data
224 * again.
225 */
226 if (i2c_dev->count >= I2C_FIFO_FULL_THLD)
227 sprd_i2c_set_fifo_full_int(i2c_dev, 1);
228 } else {
229 sprd_i2c_write_bytes(i2c_dev, i2c_dev->buf, need_tran);
230 i2c_dev->buf += need_tran;
231 i2c_dev->count -= need_tran;
232
233 /*
234 * If the write data count is arger than tx fifo depth which
235 * means we can not write all data in one time, then we should
236 * enable the tx fifo empty interrupt to write again.
237 */
238 if (i2c_count > I2C_FIFO_DEEP)
239 sprd_i2c_set_fifo_empty_int(i2c_dev, 1);
240 }
241}
242
243static int sprd_i2c_handle_msg(struct i2c_adapter *i2c_adap,
244 struct i2c_msg *msg, bool is_last_msg)
245{
246 struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
247
248 i2c_dev->msg = msg;
249 i2c_dev->buf = msg->buf;
250 i2c_dev->count = msg->len;
251
252 reinit_completion(&i2c_dev->complete);
253 sprd_i2c_reset_fifo(i2c_dev);
254 sprd_i2c_set_devaddr(i2c_dev, msg);
255 sprd_i2c_set_count(i2c_dev, msg->len);
256
257 if (msg->flags & I2C_M_RD) {
258 sprd_i2c_opt_mode(i2c_dev, 1);
259 sprd_i2c_send_stop(i2c_dev, 1);
260 } else {
261 sprd_i2c_opt_mode(i2c_dev, 0);
262 sprd_i2c_send_stop(i2c_dev, !!is_last_msg);
263 }
264
265 /*
266 * We should enable rx fifo full interrupt to get data when receiving
267 * full data.
268 */
269 if (msg->flags & I2C_M_RD)
270 sprd_i2c_set_fifo_full_int(i2c_dev, 1);
271 else
272 sprd_i2c_data_transfer(i2c_dev);
273
274 sprd_i2c_opt_start(i2c_dev);
275
276 wait_for_completion(&i2c_dev->complete);
277
278 return i2c_dev->err;
279}
280
281static int sprd_i2c_master_xfer(struct i2c_adapter *i2c_adap,
282 struct i2c_msg *msgs, int num)
283{
284 struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
285 int im, ret;
286
287 ret = pm_runtime_get_sync(i2c_dev->dev);
288 if (ret < 0)
289 return ret;
290
291 for (im = 0; im < num - 1; im++) {
292 ret = sprd_i2c_handle_msg(i2c_adap, &msgs[im], 0);
293 if (ret)
294 goto err_msg;
295 }
296
297 ret = sprd_i2c_handle_msg(i2c_adap, &msgs[im++], 1);
298
299err_msg:
300 pm_runtime_mark_last_busy(i2c_dev->dev);
301 pm_runtime_put_autosuspend(i2c_dev->dev);
302
303 return ret < 0 ? ret : im;
304}
305
306static u32 sprd_i2c_func(struct i2c_adapter *adap)
307{
308 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
309}
310
311static const struct i2c_algorithm sprd_i2c_algo = {
312 .master_xfer = sprd_i2c_master_xfer,
313 .functionality = sprd_i2c_func,
314};
315
316static void sprd_i2c_set_clk(struct sprd_i2c *i2c_dev, u32 freq)
317{
318 u32 apb_clk = i2c_dev->src_clk;
319 /*
320 * From I2C databook, the prescale calculation formula:
321 * prescale = freq_i2c / (4 * freq_scl) - 1;
322 */
323 u32 i2c_dvd = apb_clk / (4 * freq) - 1;
324 /*
325 * From I2C databook, the high period of SCL clock is recommended as
326 * 40% (2/5), and the low period of SCL clock is recommended as 60%
327 * (3/5), then the formula should be:
328 * high = (prescale * 2 * 2) / 5
329 * low = (prescale * 2 * 3) / 5
330 */
331 u32 high = ((i2c_dvd << 1) * 2) / 5;
332 u32 low = ((i2c_dvd << 1) * 3) / 5;
333 u32 div0 = I2C_ADDR_DVD0_CALC(high, low);
334 u32 div1 = I2C_ADDR_DVD1_CALC(high, low);
335
336 writel(div0, i2c_dev->base + ADDR_DVD0);
337 writel(div1, i2c_dev->base + ADDR_DVD1);
338
339 /* Start hold timing = hold time(us) * source clock */
340 if (freq == 400000)
341 writel((6 * apb_clk) / 10000000, i2c_dev->base + ADDR_STA0_DVD);
342 else if (freq == 100000)
343 writel((4 * apb_clk) / 1000000, i2c_dev->base + ADDR_STA0_DVD);
344}
345
346static void sprd_i2c_enable(struct sprd_i2c *i2c_dev)
347{
348 u32 tmp = I2C_DVD_OPT;
349
350 writel(tmp, i2c_dev->base + I2C_CTL);
351
352 sprd_i2c_set_full_thld(i2c_dev, I2C_FIFO_FULL_THLD);
353 sprd_i2c_set_empty_thld(i2c_dev, I2C_FIFO_EMPTY_THLD);
354
355 sprd_i2c_set_clk(i2c_dev, i2c_dev->bus_freq);
356 sprd_i2c_reset_fifo(i2c_dev);
357 sprd_i2c_clear_irq(i2c_dev);
358
359 tmp = readl(i2c_dev->base + I2C_CTL);
360 writel(tmp | I2C_EN | I2C_INT_EN, i2c_dev->base + I2C_CTL);
361}
362
363static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id)
364{
365 struct sprd_i2c *i2c_dev = dev_id;
366 struct i2c_msg *msg = i2c_dev->msg;
367 bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
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_dev->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
407static 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 bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
412 u32 i2c_tran;
413
414 if (msg->flags & I2C_M_RD)
415 i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
416 else
417 i2c_tran = i2c_dev->count;
418
419 /*
420 * If we did not get one ACK from slave when writing data, then we
421 * should finish this transmission since we got some errors.
422 *
423 * When writing data, if i2c_tran == 0 which means we have writen
424 * done all data, then we can finish this transmission.
425 *
426 * When reading data, if conut < rx fifo full threshold, which
427 * means we can read all data in one time, then we can finish this
428 * transmission too.
429 */
430 if (!i2c_tran || !ack) {
431 sprd_i2c_clear_start(i2c_dev);
432 sprd_i2c_clear_irq(i2c_dev);
433 }
434
435 sprd_i2c_set_fifo_empty_int(i2c_dev, 0);
436 sprd_i2c_set_fifo_full_int(i2c_dev, 0);
437
438 return IRQ_WAKE_THREAD;
439}
440
441static int sprd_i2c_clk_init(struct sprd_i2c *i2c_dev)
442{
443 struct clk *clk_i2c, *clk_parent;
444
445 clk_i2c = devm_clk_get(i2c_dev->dev, "i2c");
446 if (IS_ERR(clk_i2c)) {
447 dev_warn(i2c_dev->dev, "i2c%d can't get the i2c clock\n",
448 i2c_dev->adap.nr);
449 clk_i2c = NULL;
450 }
451
452 clk_parent = devm_clk_get(i2c_dev->dev, "source");
453 if (IS_ERR(clk_parent)) {
454 dev_warn(i2c_dev->dev, "i2c%d can't get the source clock\n",
455 i2c_dev->adap.nr);
456 clk_parent = NULL;
457 }
458
459 if (clk_set_parent(clk_i2c, clk_parent))
460 i2c_dev->src_clk = clk_get_rate(clk_i2c);
461 else
462 i2c_dev->src_clk = 26000000;
463
464 dev_dbg(i2c_dev->dev, "i2c%d set source clock is %d\n",
465 i2c_dev->adap.nr, i2c_dev->src_clk);
466
467 i2c_dev->clk = devm_clk_get(i2c_dev->dev, "enable");
468 if (IS_ERR(i2c_dev->clk)) {
469 dev_err(i2c_dev->dev, "i2c%d can't get the enable clock\n",
470 i2c_dev->adap.nr);
471 return PTR_ERR(i2c_dev->clk);
472 }
473
474 return 0;
475}
476
477static int sprd_i2c_probe(struct platform_device *pdev)
478{
479 struct device *dev = &pdev->dev;
480 struct sprd_i2c *i2c_dev;
481 u32 prop;
482 int ret;
483
484 pdev->id = of_alias_get_id(dev->of_node, "i2c");
485
486 i2c_dev = devm_kzalloc(dev, sizeof(struct sprd_i2c), GFP_KERNEL);
487 if (!i2c_dev)
488 return -ENOMEM;
489
490 i2c_dev->base = devm_platform_ioremap_resource(pdev, 0);
491 if (IS_ERR(i2c_dev->base))
492 return PTR_ERR(i2c_dev->base);
493
494 i2c_dev->irq = platform_get_irq(pdev, 0);
495 if (i2c_dev->irq < 0) {
496 dev_err(&pdev->dev, "failed to get irq resource\n");
497 return i2c_dev->irq;
498 }
499
500 i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
501 init_completion(&i2c_dev->complete);
502 snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),
503 "%s", "sprd-i2c");
504
505 i2c_dev->bus_freq = 100000;
506 i2c_dev->adap.owner = THIS_MODULE;
507 i2c_dev->dev = dev;
508 i2c_dev->adap.retries = 3;
509 i2c_dev->adap.algo = &sprd_i2c_algo;
510 i2c_dev->adap.algo_data = i2c_dev;
511 i2c_dev->adap.dev.parent = dev;
512 i2c_dev->adap.nr = pdev->id;
513 i2c_dev->adap.dev.of_node = dev->of_node;
514
515 if (!of_property_read_u32(dev->of_node, "clock-frequency", &prop))
516 i2c_dev->bus_freq = prop;
517
518 /* We only support 100k and 400k now, otherwise will return error. */
519 if (i2c_dev->bus_freq != 100000 && i2c_dev->bus_freq != 400000)
520 return -EINVAL;
521
522 ret = sprd_i2c_clk_init(i2c_dev);
523 if (ret)
524 return ret;
525
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
562err_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
569static 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
587static int __maybe_unused sprd_i2c_suspend_noirq(struct device *dev)
588{
589 struct sprd_i2c *i2c_dev = dev_get_drvdata(dev);
590
591 i2c_mark_adapter_suspended(&i2c_dev->adap);
592 return pm_runtime_force_suspend(dev);
593}
594
595static int __maybe_unused sprd_i2c_resume_noirq(struct device *dev)
596{
597 struct sprd_i2c *i2c_dev = dev_get_drvdata(dev);
598
599 i2c_mark_adapter_resumed(&i2c_dev->adap);
600 return pm_runtime_force_resume(dev);
601}
602
603static int __maybe_unused sprd_i2c_runtime_suspend(struct device *dev)
604{
605 struct sprd_i2c *i2c_dev = dev_get_drvdata(dev);
606
607 clk_disable_unprepare(i2c_dev->clk);
608
609 return 0;
610}
611
612static int __maybe_unused sprd_i2c_runtime_resume(struct device *dev)
613{
614 struct sprd_i2c *i2c_dev = dev_get_drvdata(dev);
615 int ret;
616
617 ret = clk_prepare_enable(i2c_dev->clk);
618 if (ret)
619 return ret;
620
621 sprd_i2c_enable(i2c_dev);
622
623 return 0;
624}
625
626static const struct dev_pm_ops sprd_i2c_pm_ops = {
627 SET_RUNTIME_PM_OPS(sprd_i2c_runtime_suspend,
628 sprd_i2c_runtime_resume, NULL)
629
630 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(sprd_i2c_suspend_noirq,
631 sprd_i2c_resume_noirq)
632};
633
634static const struct of_device_id sprd_i2c_of_match[] = {
635 { .compatible = "sprd,sc9860-i2c", },
636 {},
637};
638
639static struct platform_driver sprd_i2c_driver = {
640 .probe = sprd_i2c_probe,
641 .remove = sprd_i2c_remove,
642 .driver = {
643 .name = "sprd-i2c",
644 .of_match_table = sprd_i2c_of_match,
645 .pm = &sprd_i2c_pm_ops,
646 },
647};
648
649module_platform_driver(sprd_i2c_driver);
650
651MODULE_DESCRIPTION("Spreadtrum I2C master controller driver");
652MODULE_LICENSE("GPL v2");