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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/of_device.h>
21#include <linux/pinctrl/consumer.h>
22#include <linux/platform_device.h>
23#include <linux/pm_runtime.h>
24#include <linux/sched.h>
25#include <linux/slab.h>
26
27#define DRIVER_NAME "imx-lpi2c"
28
29#define LPI2C_PARAM 0x04
30#define LPI2C_MCR 0x10
31#define LPI2C_MSR 0x14
32#define LPI2C_MIER 0x18
33#define LPI2C_MCFGR0 0x20
34#define LPI2C_MCFGR1 0x24
35#define LPI2C_MCFGR2 0x28
36#define LPI2C_MCFGR3 0x2C
37#define LPI2C_MCCR0 0x48
38#define LPI2C_MCCR1 0x50
39#define LPI2C_MFCR 0x58
40#define LPI2C_MFSR 0x5C
41#define LPI2C_MTDR 0x60
42#define LPI2C_MRDR 0x70
43
44
45#define TRAN_DATA 0X00
46#define RECV_DATA 0X01
47#define GEN_STOP 0X02
48#define RECV_DISCARD 0X03
49#define GEN_START 0X04
50#define START_NACK 0X05
51#define START_HIGH 0X06
52#define START_HIGH_NACK 0X07
53
54#define MCR_MEN BIT(0)
55#define MCR_RST BIT(1)
56#define MCR_DOZEN BIT(2)
57#define MCR_DBGEN BIT(3)
58#define MCR_RTF BIT(8)
59#define MCR_RRF BIT(9)
60#define MSR_TDF BIT(0)
61#define MSR_RDF BIT(1)
62#define MSR_SDF BIT(9)
63#define MSR_NDF BIT(10)
64#define MSR_ALF BIT(11)
65#define MSR_MBF BIT(24)
66#define MSR_BBF BIT(25)
67#define MIER_TDIE BIT(0)
68#define MIER_RDIE BIT(1)
69#define MIER_SDIE BIT(9)
70#define MIER_NDIE BIT(10)
71#define MCFGR1_AUTOSTOP BIT(8)
72#define MCFGR1_IGNACK BIT(9)
73#define MRDR_RXEMPTY BIT(14)
74
75#define I2C_CLK_RATIO 2
76#define CHUNK_DATA 256
77
78#define I2C_PM_TIMEOUT 10
79
80enum lpi2c_imx_mode {
81 STANDARD,
82 FAST,
83 FAST_PLUS,
84 HS,
85 ULTRA_FAST,
86};
87
88enum lpi2c_imx_pincfg {
89 TWO_PIN_OD,
90 TWO_PIN_OO,
91 TWO_PIN_PP,
92 FOUR_PIN_PP,
93};
94
95struct lpi2c_imx_struct {
96 struct i2c_adapter adapter;
97 struct clk *clk;
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
111static 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
117static 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
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
144static 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
163static 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
179static 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
201static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx)
202{
203 u8 prescale, filt, sethold, clkhi, clklo, datavd;
204 unsigned int clk_rate, clk_cycle;
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->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 = (clk_cycle + I2C_CLK_RATIO) / (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
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
241 temp = (filt << 16) | (filt << 24);
242 writel(temp, lpi2c_imx->base + LPI2C_MCFGR2);
243
244
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
257static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
258{
259 unsigned int temp;
260 int ret;
261
262 ret = pm_runtime_get_sync(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
280rpm_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
287static 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
301static 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
310static 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
334static 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
339static 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
353static 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
374static 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
389
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
404 lpi2c_imx_set_rx_watermark(lpi2c_imx);
405
406
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
421static 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
429static 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
445static 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
462 if (num == 1 && msgs[0].len == 0)
463 goto stop;
464
465 lpi2c_imx->delivered = 0;
466 lpi2c_imx->msglen = msgs[i].len;
467 init_completion(&lpi2c_imx->complete);
468
469 if (msgs[i].flags & I2C_M_RD)
470 lpi2c_imx_read(lpi2c_imx, &msgs[i]);
471 else
472 lpi2c_imx_write(lpi2c_imx, &msgs[i]);
473
474 result = lpi2c_imx_msg_complete(lpi2c_imx);
475 if (result)
476 goto stop;
477
478 if (!(msgs[i].flags & I2C_M_RD)) {
479 result = lpi2c_imx_txfifo_empty(lpi2c_imx);
480 if (result)
481 goto stop;
482 }
483 }
484
485stop:
486 lpi2c_imx_stop(lpi2c_imx);
487
488 temp = readl(lpi2c_imx->base + LPI2C_MSR);
489 if ((temp & MSR_NDF) && !result)
490 result = -EIO;
491
492disable:
493 lpi2c_imx_master_disable(lpi2c_imx);
494
495 dev_dbg(&lpi2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
496 (result < 0) ? "error" : "success msg",
497 (result < 0) ? result : num);
498
499 return (result < 0) ? result : num;
500}
501
502static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id)
503{
504 struct lpi2c_imx_struct *lpi2c_imx = dev_id;
505 unsigned int temp;
506
507 lpi2c_imx_intctrl(lpi2c_imx, 0);
508 temp = readl(lpi2c_imx->base + LPI2C_MSR);
509
510 if (temp & MSR_RDF)
511 lpi2c_imx_read_rxfifo(lpi2c_imx);
512
513 if (temp & MSR_TDF)
514 lpi2c_imx_write_txfifo(lpi2c_imx);
515
516 if (temp & MSR_NDF)
517 complete(&lpi2c_imx->complete);
518
519 return IRQ_HANDLED;
520}
521
522static u32 lpi2c_imx_func(struct i2c_adapter *adapter)
523{
524 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
525 I2C_FUNC_SMBUS_READ_BLOCK_DATA;
526}
527
528static const struct i2c_algorithm lpi2c_imx_algo = {
529 .master_xfer = lpi2c_imx_xfer,
530 .functionality = lpi2c_imx_func,
531};
532
533static const struct of_device_id lpi2c_imx_of_match[] = {
534 { .compatible = "fsl,imx7ulp-lpi2c" },
535 { },
536};
537MODULE_DEVICE_TABLE(of, lpi2c_imx_of_match);
538
539static int lpi2c_imx_probe(struct platform_device *pdev)
540{
541 struct lpi2c_imx_struct *lpi2c_imx;
542 unsigned int temp;
543 int irq, ret;
544
545 lpi2c_imx = devm_kzalloc(&pdev->dev, sizeof(*lpi2c_imx), GFP_KERNEL);
546 if (!lpi2c_imx)
547 return -ENOMEM;
548
549 lpi2c_imx->base = devm_platform_ioremap_resource(pdev, 0);
550 if (IS_ERR(lpi2c_imx->base))
551 return PTR_ERR(lpi2c_imx->base);
552
553 irq = platform_get_irq(pdev, 0);
554 if (irq < 0)
555 return irq;
556
557 lpi2c_imx->adapter.owner = THIS_MODULE;
558 lpi2c_imx->adapter.algo = &lpi2c_imx_algo;
559 lpi2c_imx->adapter.dev.parent = &pdev->dev;
560 lpi2c_imx->adapter.dev.of_node = pdev->dev.of_node;
561 strlcpy(lpi2c_imx->adapter.name, pdev->name,
562 sizeof(lpi2c_imx->adapter.name));
563
564 lpi2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
565 if (IS_ERR(lpi2c_imx->clk)) {
566 dev_err(&pdev->dev, "can't get I2C peripheral clock\n");
567 return PTR_ERR(lpi2c_imx->clk);
568 }
569
570 ret = of_property_read_u32(pdev->dev.of_node,
571 "clock-frequency", &lpi2c_imx->bitrate);
572 if (ret)
573 lpi2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ;
574
575 ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, 0,
576 pdev->name, lpi2c_imx);
577 if (ret) {
578 dev_err(&pdev->dev, "can't claim irq %d\n", irq);
579 return ret;
580 }
581
582 i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx);
583 platform_set_drvdata(pdev, lpi2c_imx);
584
585 ret = clk_prepare_enable(lpi2c_imx->clk);
586 if (ret) {
587 dev_err(&pdev->dev, "clk enable failed %d\n", ret);
588 return ret;
589 }
590
591 pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
592 pm_runtime_use_autosuspend(&pdev->dev);
593 pm_runtime_get_noresume(&pdev->dev);
594 pm_runtime_set_active(&pdev->dev);
595 pm_runtime_enable(&pdev->dev);
596
597 temp = readl(lpi2c_imx->base + LPI2C_PARAM);
598 lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
599 lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
600
601 ret = i2c_add_adapter(&lpi2c_imx->adapter);
602 if (ret)
603 goto rpm_disable;
604
605 pm_runtime_mark_last_busy(&pdev->dev);
606 pm_runtime_put_autosuspend(&pdev->dev);
607
608 dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
609
610 return 0;
611
612rpm_disable:
613 pm_runtime_put(&pdev->dev);
614 pm_runtime_disable(&pdev->dev);
615 pm_runtime_dont_use_autosuspend(&pdev->dev);
616
617 return ret;
618}
619
620static int lpi2c_imx_remove(struct platform_device *pdev)
621{
622 struct lpi2c_imx_struct *lpi2c_imx = platform_get_drvdata(pdev);
623
624 i2c_del_adapter(&lpi2c_imx->adapter);
625
626 pm_runtime_disable(&pdev->dev);
627 pm_runtime_dont_use_autosuspend(&pdev->dev);
628
629 return 0;
630}
631
632static int __maybe_unused lpi2c_runtime_suspend(struct device *dev)
633{
634 struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
635
636 clk_disable_unprepare(lpi2c_imx->clk);
637 pinctrl_pm_select_sleep_state(dev);
638
639 return 0;
640}
641
642static 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_prepare_enable(lpi2c_imx->clk);
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
657static 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
664static struct platform_driver lpi2c_imx_driver = {
665 .probe = lpi2c_imx_probe,
666 .remove = 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
674module_platform_driver(lpi2c_imx_driver);
675
676MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
677MODULE_DESCRIPTION("I2C adapter driver for LPI2C bus");
678MODULE_LICENSE("GPL");
679
