This source file includes following definitions.
- cdns_i2c_clear_bus_hold
- cdns_is_holdquirk
- cdns_i2c_isr
- cdns_i2c_mrecv
- cdns_i2c_msend
- cdns_i2c_master_reset
- cdns_i2c_process_msg
- cdns_i2c_master_xfer
- cdns_i2c_func
- cdns_i2c_calc_divs
- cdns_i2c_setclk
- cdns_i2c_clk_notifier_cb
- cdns_i2c_runtime_suspend
- cdns_i2c_runtime_resume
- cdns_i2c_probe
- cdns_i2c_remove
1
2
3
4
5
6
7
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/i2c.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/of.h>
16 #include <linux/pm_runtime.h>
17
18
19 #define CDNS_I2C_CR_OFFSET 0x00
20 #define CDNS_I2C_SR_OFFSET 0x04
21 #define CDNS_I2C_ADDR_OFFSET 0x08
22 #define CDNS_I2C_DATA_OFFSET 0x0C
23 #define CDNS_I2C_ISR_OFFSET 0x10
24 #define CDNS_I2C_XFER_SIZE_OFFSET 0x14
25 #define CDNS_I2C_TIME_OUT_OFFSET 0x1C
26 #define CDNS_I2C_IER_OFFSET 0x24
27 #define CDNS_I2C_IDR_OFFSET 0x28
28
29
30 #define CDNS_I2C_CR_HOLD BIT(4)
31 #define CDNS_I2C_CR_ACK_EN BIT(3)
32 #define CDNS_I2C_CR_NEA BIT(2)
33 #define CDNS_I2C_CR_MS BIT(1)
34
35 #define CDNS_I2C_CR_RW BIT(0)
36
37 #define CDNS_I2C_CR_CLR_FIFO BIT(6)
38 #define CDNS_I2C_CR_DIVA_SHIFT 14
39 #define CDNS_I2C_CR_DIVA_MASK (3 << CDNS_I2C_CR_DIVA_SHIFT)
40 #define CDNS_I2C_CR_DIVB_SHIFT 8
41 #define CDNS_I2C_CR_DIVB_MASK (0x3f << CDNS_I2C_CR_DIVB_SHIFT)
42
43
44 #define CDNS_I2C_SR_BA BIT(8)
45 #define CDNS_I2C_SR_RXDV BIT(5)
46
47
48
49
50
51
52
53 #define CDNS_I2C_ADDR_MASK 0x000003FF
54
55
56
57
58
59
60 #define CDNS_I2C_IXR_ARB_LOST BIT(9)
61 #define CDNS_I2C_IXR_RX_UNF BIT(7)
62 #define CDNS_I2C_IXR_TX_OVF BIT(6)
63 #define CDNS_I2C_IXR_RX_OVF BIT(5)
64 #define CDNS_I2C_IXR_SLV_RDY BIT(4)
65 #define CDNS_I2C_IXR_TO BIT(3)
66 #define CDNS_I2C_IXR_NACK BIT(2)
67 #define CDNS_I2C_IXR_DATA BIT(1)
68 #define CDNS_I2C_IXR_COMP BIT(0)
69
70 #define CDNS_I2C_IXR_ALL_INTR_MASK (CDNS_I2C_IXR_ARB_LOST | \
71 CDNS_I2C_IXR_RX_UNF | \
72 CDNS_I2C_IXR_TX_OVF | \
73 CDNS_I2C_IXR_RX_OVF | \
74 CDNS_I2C_IXR_SLV_RDY | \
75 CDNS_I2C_IXR_TO | \
76 CDNS_I2C_IXR_NACK | \
77 CDNS_I2C_IXR_DATA | \
78 CDNS_I2C_IXR_COMP)
79
80 #define CDNS_I2C_IXR_ERR_INTR_MASK (CDNS_I2C_IXR_ARB_LOST | \
81 CDNS_I2C_IXR_RX_UNF | \
82 CDNS_I2C_IXR_TX_OVF | \
83 CDNS_I2C_IXR_RX_OVF | \
84 CDNS_I2C_IXR_NACK)
85
86 #define CDNS_I2C_ENABLED_INTR_MASK (CDNS_I2C_IXR_ARB_LOST | \
87 CDNS_I2C_IXR_RX_UNF | \
88 CDNS_I2C_IXR_TX_OVF | \
89 CDNS_I2C_IXR_RX_OVF | \
90 CDNS_I2C_IXR_NACK | \
91 CDNS_I2C_IXR_DATA | \
92 CDNS_I2C_IXR_COMP)
93
94 #define CDNS_I2C_TIMEOUT msecs_to_jiffies(1000)
95
96 #define CNDS_I2C_PM_TIMEOUT 1000
97
98 #define CDNS_I2C_FIFO_DEPTH 16
99
100 #define CDNS_I2C_DATA_INTR_DEPTH (CDNS_I2C_FIFO_DEPTH - 2)
101 #define CDNS_I2C_MAX_TRANSFER_SIZE 255
102
103 #define CDNS_I2C_TRANSFER_SIZE (CDNS_I2C_MAX_TRANSFER_SIZE - 3)
104
105 #define DRIVER_NAME "cdns-i2c"
106
107 #define CDNS_I2C_SPEED_MAX 400000
108 #define CDNS_I2C_SPEED_DEFAULT 100000
109
110 #define CDNS_I2C_DIVA_MAX 4
111 #define CDNS_I2C_DIVB_MAX 64
112
113 #define CDNS_I2C_TIMEOUT_MAX 0xFF
114
115 #define CDNS_I2C_BROKEN_HOLD_BIT BIT(0)
116
117 #define cdns_i2c_readreg(offset) readl_relaxed(id->membase + offset)
118 #define cdns_i2c_writereg(val, offset) writel_relaxed(val, id->membase + offset)
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142 struct cdns_i2c {
143 struct device *dev;
144 void __iomem *membase;
145 struct i2c_adapter adap;
146 struct i2c_msg *p_msg;
147 int err_status;
148 struct completion xfer_done;
149 unsigned char *p_send_buf;
150 unsigned char *p_recv_buf;
151 unsigned int send_count;
152 unsigned int recv_count;
153 unsigned int curr_recv_count;
154 int irq;
155 unsigned long input_clk;
156 unsigned int i2c_clk;
157 unsigned int bus_hold_flag;
158 struct clk *clk;
159 struct notifier_block clk_rate_change_nb;
160 u32 quirks;
161 };
162
163 struct cdns_platform_data {
164 u32 quirks;
165 };
166
167 #define to_cdns_i2c(_nb) container_of(_nb, struct cdns_i2c, \
168 clk_rate_change_nb)
169
170
171
172
173
174
175
176 static void cdns_i2c_clear_bus_hold(struct cdns_i2c *id)
177 {
178 u32 reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
179 if (reg & CDNS_I2C_CR_HOLD)
180 cdns_i2c_writereg(reg & ~CDNS_I2C_CR_HOLD, CDNS_I2C_CR_OFFSET);
181 }
182
183 static inline bool cdns_is_holdquirk(struct cdns_i2c *id, bool hold_wrkaround)
184 {
185 return (hold_wrkaround &&
186 (id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1));
187 }
188
189
190
191
192
193
194
195
196
197
198
199 static irqreturn_t cdns_i2c_isr(int irq, void *ptr)
200 {
201 unsigned int isr_status, avail_bytes, updatetx;
202 unsigned int bytes_to_send;
203 bool hold_quirk;
204 struct cdns_i2c *id = ptr;
205
206 int done_flag = 0;
207 irqreturn_t status = IRQ_NONE;
208
209 isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
210 cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET);
211
212
213 if (isr_status & (CDNS_I2C_IXR_NACK | CDNS_I2C_IXR_ARB_LOST)) {
214 done_flag = 1;
215 status = IRQ_HANDLED;
216 }
217
218
219
220
221
222 updatetx = 0;
223 if (id->recv_count > id->curr_recv_count)
224 updatetx = 1;
225
226 hold_quirk = (id->quirks & CDNS_I2C_BROKEN_HOLD_BIT) && updatetx;
227
228
229 if (id->p_recv_buf &&
230 ((isr_status & CDNS_I2C_IXR_COMP) ||
231 (isr_status & CDNS_I2C_IXR_DATA))) {
232
233 while (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) &
234 CDNS_I2C_SR_RXDV) {
235
236
237
238
239
240 if ((id->recv_count < CDNS_I2C_FIFO_DEPTH) &&
241 !id->bus_hold_flag)
242 cdns_i2c_clear_bus_hold(id);
243
244 *(id->p_recv_buf)++ =
245 cdns_i2c_readreg(CDNS_I2C_DATA_OFFSET);
246 id->recv_count--;
247 id->curr_recv_count--;
248
249 if (cdns_is_holdquirk(id, hold_quirk))
250 break;
251 }
252
253
254
255
256
257
258
259
260 if (cdns_is_holdquirk(id, hold_quirk)) {
261
262 while (cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET) !=
263 (id->curr_recv_count - CDNS_I2C_FIFO_DEPTH))
264 ;
265
266
267
268
269
270 if (((int)(id->recv_count) - CDNS_I2C_FIFO_DEPTH) >
271 CDNS_I2C_TRANSFER_SIZE) {
272 cdns_i2c_writereg(CDNS_I2C_TRANSFER_SIZE,
273 CDNS_I2C_XFER_SIZE_OFFSET);
274 id->curr_recv_count = CDNS_I2C_TRANSFER_SIZE +
275 CDNS_I2C_FIFO_DEPTH;
276 } else {
277 cdns_i2c_writereg(id->recv_count -
278 CDNS_I2C_FIFO_DEPTH,
279 CDNS_I2C_XFER_SIZE_OFFSET);
280 id->curr_recv_count = id->recv_count;
281 }
282 } else if (id->recv_count && !hold_quirk &&
283 !id->curr_recv_count) {
284
285
286 cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,
287 CDNS_I2C_ADDR_OFFSET);
288
289 if (id->recv_count > CDNS_I2C_TRANSFER_SIZE) {
290 cdns_i2c_writereg(CDNS_I2C_TRANSFER_SIZE,
291 CDNS_I2C_XFER_SIZE_OFFSET);
292 id->curr_recv_count = CDNS_I2C_TRANSFER_SIZE;
293 } else {
294 cdns_i2c_writereg(id->recv_count,
295 CDNS_I2C_XFER_SIZE_OFFSET);
296 id->curr_recv_count = id->recv_count;
297 }
298 }
299
300
301 if ((isr_status & CDNS_I2C_IXR_COMP) && !id->recv_count) {
302 if (!id->bus_hold_flag)
303 cdns_i2c_clear_bus_hold(id);
304 done_flag = 1;
305 }
306
307 status = IRQ_HANDLED;
308 }
309
310
311 if ((isr_status & CDNS_I2C_IXR_COMP) && !id->p_recv_buf) {
312
313
314
315
316 if (id->send_count) {
317 avail_bytes = CDNS_I2C_FIFO_DEPTH -
318 cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET);
319 if (id->send_count > avail_bytes)
320 bytes_to_send = avail_bytes;
321 else
322 bytes_to_send = id->send_count;
323
324 while (bytes_to_send--) {
325 cdns_i2c_writereg(
326 (*(id->p_send_buf)++),
327 CDNS_I2C_DATA_OFFSET);
328 id->send_count--;
329 }
330 } else {
331
332
333
334
335
336 done_flag = 1;
337 }
338 if (!id->send_count && !id->bus_hold_flag)
339 cdns_i2c_clear_bus_hold(id);
340
341 status = IRQ_HANDLED;
342 }
343
344
345 id->err_status = isr_status & CDNS_I2C_IXR_ERR_INTR_MASK;
346 if (id->err_status)
347 status = IRQ_HANDLED;
348
349 if (done_flag)
350 complete(&id->xfer_done);
351
352 return status;
353 }
354
355
356
357
358
359 static void cdns_i2c_mrecv(struct cdns_i2c *id)
360 {
361 unsigned int ctrl_reg;
362 unsigned int isr_status;
363
364 id->p_recv_buf = id->p_msg->buf;
365 id->recv_count = id->p_msg->len;
366
367
368 ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
369 ctrl_reg |= CDNS_I2C_CR_RW | CDNS_I2C_CR_CLR_FIFO;
370
371 if (id->p_msg->flags & I2C_M_RECV_LEN)
372 id->recv_count = I2C_SMBUS_BLOCK_MAX + 1;
373
374 id->curr_recv_count = id->recv_count;
375
376
377
378
379
380 if ((id->recv_count > CDNS_I2C_FIFO_DEPTH) || id->bus_hold_flag)
381 ctrl_reg |= CDNS_I2C_CR_HOLD;
382 else
383 ctrl_reg = ctrl_reg & ~CDNS_I2C_CR_HOLD;
384
385 cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET);
386
387
388 isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
389 cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET);
390
391
392
393
394
395
396
397 if (id->recv_count > CDNS_I2C_TRANSFER_SIZE) {
398 cdns_i2c_writereg(CDNS_I2C_TRANSFER_SIZE,
399 CDNS_I2C_XFER_SIZE_OFFSET);
400 id->curr_recv_count = CDNS_I2C_TRANSFER_SIZE;
401 } else {
402 cdns_i2c_writereg(id->recv_count, CDNS_I2C_XFER_SIZE_OFFSET);
403 }
404
405
406 cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,
407 CDNS_I2C_ADDR_OFFSET);
408
409 if (!id->bus_hold_flag &&
410 ((id->p_msg->flags & I2C_M_RECV_LEN) != I2C_M_RECV_LEN) &&
411 (id->recv_count <= CDNS_I2C_FIFO_DEPTH))
412 cdns_i2c_clear_bus_hold(id);
413 cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET);
414 }
415
416
417
418
419
420 static void cdns_i2c_msend(struct cdns_i2c *id)
421 {
422 unsigned int avail_bytes;
423 unsigned int bytes_to_send;
424 unsigned int ctrl_reg;
425 unsigned int isr_status;
426
427 id->p_recv_buf = NULL;
428 id->p_send_buf = id->p_msg->buf;
429 id->send_count = id->p_msg->len;
430
431
432 ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
433 ctrl_reg &= ~CDNS_I2C_CR_RW;
434 ctrl_reg |= CDNS_I2C_CR_CLR_FIFO;
435
436
437
438
439
440 if ((id->send_count > CDNS_I2C_FIFO_DEPTH) || id->bus_hold_flag)
441 ctrl_reg |= CDNS_I2C_CR_HOLD;
442 else
443 ctrl_reg = ctrl_reg & ~CDNS_I2C_CR_HOLD;
444
445 cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET);
446
447
448 isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
449 cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET);
450
451
452
453
454
455
456 avail_bytes = CDNS_I2C_FIFO_DEPTH -
457 cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET);
458
459 if (id->send_count > avail_bytes)
460 bytes_to_send = avail_bytes;
461 else
462 bytes_to_send = id->send_count;
463
464 while (bytes_to_send--) {
465 cdns_i2c_writereg((*(id->p_send_buf)++), CDNS_I2C_DATA_OFFSET);
466 id->send_count--;
467 }
468
469
470
471
472
473 if (!id->bus_hold_flag && !id->send_count)
474 cdns_i2c_clear_bus_hold(id);
475
476 cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,
477 CDNS_I2C_ADDR_OFFSET);
478
479 cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET);
480 }
481
482
483
484
485
486
487
488
489 static void cdns_i2c_master_reset(struct i2c_adapter *adap)
490 {
491 struct cdns_i2c *id = adap->algo_data;
492 u32 regval;
493
494
495 cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK, CDNS_I2C_IDR_OFFSET);
496
497 regval = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
498 regval &= ~CDNS_I2C_CR_HOLD;
499 regval |= CDNS_I2C_CR_CLR_FIFO;
500 cdns_i2c_writereg(regval, CDNS_I2C_CR_OFFSET);
501
502 cdns_i2c_writereg(0, CDNS_I2C_XFER_SIZE_OFFSET);
503
504 regval = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
505 cdns_i2c_writereg(regval, CDNS_I2C_ISR_OFFSET);
506
507 regval = cdns_i2c_readreg(CDNS_I2C_SR_OFFSET);
508 cdns_i2c_writereg(regval, CDNS_I2C_SR_OFFSET);
509 }
510
511 static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
512 struct i2c_adapter *adap)
513 {
514 unsigned long time_left;
515 u32 reg;
516
517 id->p_msg = msg;
518 id->err_status = 0;
519 reinit_completion(&id->xfer_done);
520
521
522 reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
523 if (msg->flags & I2C_M_TEN) {
524 if (reg & CDNS_I2C_CR_NEA)
525 cdns_i2c_writereg(reg & ~CDNS_I2C_CR_NEA,
526 CDNS_I2C_CR_OFFSET);
527 } else {
528 if (!(reg & CDNS_I2C_CR_NEA))
529 cdns_i2c_writereg(reg | CDNS_I2C_CR_NEA,
530 CDNS_I2C_CR_OFFSET);
531 }
532
533
534 if (msg->flags & I2C_M_RD)
535 cdns_i2c_mrecv(id);
536 else
537 cdns_i2c_msend(id);
538
539
540 time_left = wait_for_completion_timeout(&id->xfer_done, adap->timeout);
541 if (time_left == 0) {
542 cdns_i2c_master_reset(adap);
543 dev_err(id->adap.dev.parent,
544 "timeout waiting on completion\n");
545 return -ETIMEDOUT;
546 }
547
548 cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK,
549 CDNS_I2C_IDR_OFFSET);
550
551
552 if (id->err_status & CDNS_I2C_IXR_ARB_LOST)
553 return -EAGAIN;
554
555 return 0;
556 }
557
558
559
560
561
562
563
564
565
566
567
568 static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
569 int num)
570 {
571 int ret, count;
572 u32 reg;
573 struct cdns_i2c *id = adap->algo_data;
574 bool hold_quirk;
575
576 ret = pm_runtime_get_sync(id->dev);
577 if (ret < 0)
578 return ret;
579
580 if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA) {
581 ret = -EAGAIN;
582 goto out;
583 }
584
585 hold_quirk = !!(id->quirks & CDNS_I2C_BROKEN_HOLD_BIT);
586
587
588
589
590 if (num > 1) {
591
592
593
594
595
596
597
598 for (count = 0; (count < num - 1 && hold_quirk); count++) {
599 if (msgs[count].flags & I2C_M_RD) {
600 dev_warn(adap->dev.parent,
601 "Can't do repeated start after a receive message\n");
602 ret = -EOPNOTSUPP;
603 goto out;
604 }
605 }
606 id->bus_hold_flag = 1;
607 reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
608 reg |= CDNS_I2C_CR_HOLD;
609 cdns_i2c_writereg(reg, CDNS_I2C_CR_OFFSET);
610 } else {
611 id->bus_hold_flag = 0;
612 }
613
614
615 for (count = 0; count < num; count++, msgs++) {
616 if (count == (num - 1))
617 id->bus_hold_flag = 0;
618
619 ret = cdns_i2c_process_msg(id, msgs, adap);
620 if (ret)
621 goto out;
622
623
624 if (id->err_status) {
625 cdns_i2c_master_reset(adap);
626
627 if (id->err_status & CDNS_I2C_IXR_NACK) {
628 ret = -ENXIO;
629 goto out;
630 }
631 ret = -EIO;
632 goto out;
633 }
634 }
635
636 ret = num;
637 out:
638 pm_runtime_mark_last_busy(id->dev);
639 pm_runtime_put_autosuspend(id->dev);
640 return ret;
641 }
642
643
644
645
646
647
648
649 static u32 cdns_i2c_func(struct i2c_adapter *adap)
650 {
651 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |
652 (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
653 I2C_FUNC_SMBUS_BLOCK_DATA;
654 }
655
656 static const struct i2c_algorithm cdns_i2c_algo = {
657 .master_xfer = cdns_i2c_master_xfer,
658 .functionality = cdns_i2c_func,
659 };
660
661
662
663
664
665
666
667
668
669
670
671
672
673 static int cdns_i2c_calc_divs(unsigned long *f, unsigned long input_clk,
674 unsigned int *a, unsigned int *b)
675 {
676 unsigned long fscl = *f, best_fscl = *f, actual_fscl, temp;
677 unsigned int div_a, div_b, calc_div_a = 0, calc_div_b = 0;
678 unsigned int last_error, current_error;
679
680
681 temp = input_clk / (22 * fscl);
682
683
684
685
686
687 if (!temp || (temp > (CDNS_I2C_DIVA_MAX * CDNS_I2C_DIVB_MAX)))
688 return -EINVAL;
689
690 last_error = -1;
691 for (div_a = 0; div_a < CDNS_I2C_DIVA_MAX; div_a++) {
692 div_b = DIV_ROUND_UP(input_clk, 22 * fscl * (div_a + 1));
693
694 if ((div_b < 1) || (div_b > CDNS_I2C_DIVB_MAX))
695 continue;
696 div_b--;
697
698 actual_fscl = input_clk / (22 * (div_a + 1) * (div_b + 1));
699
700 if (actual_fscl > fscl)
701 continue;
702
703 current_error = ((actual_fscl > fscl) ? (actual_fscl - fscl) :
704 (fscl - actual_fscl));
705
706 if (last_error > current_error) {
707 calc_div_a = div_a;
708 calc_div_b = div_b;
709 best_fscl = actual_fscl;
710 last_error = current_error;
711 }
712 }
713
714 *a = calc_div_a;
715 *b = calc_div_b;
716 *f = best_fscl;
717
718 return 0;
719 }
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737 static int cdns_i2c_setclk(unsigned long clk_in, struct cdns_i2c *id)
738 {
739 unsigned int div_a, div_b;
740 unsigned int ctrl_reg;
741 int ret = 0;
742 unsigned long fscl = id->i2c_clk;
743
744 ret = cdns_i2c_calc_divs(&fscl, clk_in, &div_a, &div_b);
745 if (ret)
746 return ret;
747
748 ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
749 ctrl_reg &= ~(CDNS_I2C_CR_DIVA_MASK | CDNS_I2C_CR_DIVB_MASK);
750 ctrl_reg |= ((div_a << CDNS_I2C_CR_DIVA_SHIFT) |
751 (div_b << CDNS_I2C_CR_DIVB_SHIFT));
752 cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET);
753
754 return 0;
755 }
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773 static int cdns_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
774 event, void *data)
775 {
776 struct clk_notifier_data *ndata = data;
777 struct cdns_i2c *id = to_cdns_i2c(nb);
778
779 if (pm_runtime_suspended(id->dev))
780 return NOTIFY_OK;
781
782 switch (event) {
783 case PRE_RATE_CHANGE:
784 {
785 unsigned long input_clk = ndata->new_rate;
786 unsigned long fscl = id->i2c_clk;
787 unsigned int div_a, div_b;
788 int ret;
789
790 ret = cdns_i2c_calc_divs(&fscl, input_clk, &div_a, &div_b);
791 if (ret) {
792 dev_warn(id->adap.dev.parent,
793 "clock rate change rejected\n");
794 return NOTIFY_STOP;
795 }
796
797
798 if (ndata->new_rate > ndata->old_rate)
799 cdns_i2c_setclk(ndata->new_rate, id);
800
801 return NOTIFY_OK;
802 }
803 case POST_RATE_CHANGE:
804 id->input_clk = ndata->new_rate;
805
806 if (ndata->new_rate < ndata->old_rate)
807 cdns_i2c_setclk(ndata->new_rate, id);
808 return NOTIFY_OK;
809 case ABORT_RATE_CHANGE:
810
811 if (ndata->new_rate > ndata->old_rate)
812 cdns_i2c_setclk(ndata->old_rate, id);
813 return NOTIFY_OK;
814 default:
815 return NOTIFY_DONE;
816 }
817 }
818
819
820
821
822
823
824
825
826
827 static int __maybe_unused cdns_i2c_runtime_suspend(struct device *dev)
828 {
829 struct cdns_i2c *xi2c = dev_get_drvdata(dev);
830
831 clk_disable(xi2c->clk);
832
833 return 0;
834 }
835
836
837
838
839
840
841
842
843
844 static int __maybe_unused cdns_i2c_runtime_resume(struct device *dev)
845 {
846 struct cdns_i2c *xi2c = dev_get_drvdata(dev);
847 int ret;
848
849 ret = clk_enable(xi2c->clk);
850 if (ret) {
851 dev_err(dev, "Cannot enable clock.\n");
852 return ret;
853 }
854
855 return 0;
856 }
857
858 static const struct dev_pm_ops cdns_i2c_dev_pm_ops = {
859 SET_RUNTIME_PM_OPS(cdns_i2c_runtime_suspend,
860 cdns_i2c_runtime_resume, NULL)
861 };
862
863 static const struct cdns_platform_data r1p10_i2c_def = {
864 .quirks = CDNS_I2C_BROKEN_HOLD_BIT,
865 };
866
867 static const struct of_device_id cdns_i2c_of_match[] = {
868 { .compatible = "cdns,i2c-r1p10", .data = &r1p10_i2c_def },
869 { .compatible = "cdns,i2c-r1p14",},
870 { }
871 };
872 MODULE_DEVICE_TABLE(of, cdns_i2c_of_match);
873
874
875
876
877
878
879
880
881
882
883
884 static int cdns_i2c_probe(struct platform_device *pdev)
885 {
886 struct resource *r_mem;
887 struct cdns_i2c *id;
888 int ret;
889 const struct of_device_id *match;
890
891 id = devm_kzalloc(&pdev->dev, sizeof(*id), GFP_KERNEL);
892 if (!id)
893 return -ENOMEM;
894
895 id->dev = &pdev->dev;
896 platform_set_drvdata(pdev, id);
897
898 match = of_match_node(cdns_i2c_of_match, pdev->dev.of_node);
899 if (match && match->data) {
900 const struct cdns_platform_data *data = match->data;
901 id->quirks = data->quirks;
902 }
903
904 r_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
905 id->membase = devm_ioremap_resource(&pdev->dev, r_mem);
906 if (IS_ERR(id->membase))
907 return PTR_ERR(id->membase);
908
909 id->irq = platform_get_irq(pdev, 0);
910
911 id->adap.owner = THIS_MODULE;
912 id->adap.dev.of_node = pdev->dev.of_node;
913 id->adap.algo = &cdns_i2c_algo;
914 id->adap.timeout = CDNS_I2C_TIMEOUT;
915 id->adap.retries = 3;
916 id->adap.algo_data = id;
917 id->adap.dev.parent = &pdev->dev;
918 init_completion(&id->xfer_done);
919 snprintf(id->adap.name, sizeof(id->adap.name),
920 "Cadence I2C at %08lx", (unsigned long)r_mem->start);
921
922 id->clk = devm_clk_get(&pdev->dev, NULL);
923 if (IS_ERR(id->clk)) {
924 dev_err(&pdev->dev, "input clock not found.\n");
925 return PTR_ERR(id->clk);
926 }
927 ret = clk_prepare_enable(id->clk);
928 if (ret)
929 dev_err(&pdev->dev, "Unable to enable clock.\n");
930
931 pm_runtime_enable(id->dev);
932 pm_runtime_set_autosuspend_delay(id->dev, CNDS_I2C_PM_TIMEOUT);
933 pm_runtime_use_autosuspend(id->dev);
934 pm_runtime_set_active(id->dev);
935
936 id->clk_rate_change_nb.notifier_call = cdns_i2c_clk_notifier_cb;
937 if (clk_notifier_register(id->clk, &id->clk_rate_change_nb))
938 dev_warn(&pdev->dev, "Unable to register clock notifier.\n");
939 id->input_clk = clk_get_rate(id->clk);
940
941 ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
942 &id->i2c_clk);
943 if (ret || (id->i2c_clk > CDNS_I2C_SPEED_MAX))
944 id->i2c_clk = CDNS_I2C_SPEED_DEFAULT;
945
946 cdns_i2c_writereg(CDNS_I2C_CR_ACK_EN | CDNS_I2C_CR_NEA | CDNS_I2C_CR_MS,
947 CDNS_I2C_CR_OFFSET);
948
949 ret = cdns_i2c_setclk(id->input_clk, id);
950 if (ret) {
951 dev_err(&pdev->dev, "invalid SCL clock: %u Hz\n", id->i2c_clk);
952 ret = -EINVAL;
953 goto err_clk_dis;
954 }
955
956 ret = devm_request_irq(&pdev->dev, id->irq, cdns_i2c_isr, 0,
957 DRIVER_NAME, id);
958 if (ret) {
959 dev_err(&pdev->dev, "cannot get irq %d\n", id->irq);
960 goto err_clk_dis;
961 }
962
963
964
965
966
967
968
969
970 cdns_i2c_writereg(CDNS_I2C_TIMEOUT_MAX, CDNS_I2C_TIME_OUT_OFFSET);
971
972 ret = i2c_add_adapter(&id->adap);
973 if (ret < 0)
974 goto err_clk_dis;
975
976 dev_info(&pdev->dev, "%u kHz mmio %08lx irq %d\n",
977 id->i2c_clk / 1000, (unsigned long)r_mem->start, id->irq);
978
979 return 0;
980
981 err_clk_dis:
982 clk_disable_unprepare(id->clk);
983 pm_runtime_set_suspended(&pdev->dev);
984 pm_runtime_disable(&pdev->dev);
985 return ret;
986 }
987
988
989
990
991
992
993
994
995
996 static int cdns_i2c_remove(struct platform_device *pdev)
997 {
998 struct cdns_i2c *id = platform_get_drvdata(pdev);
999
1000 i2c_del_adapter(&id->adap);
1001 clk_notifier_unregister(id->clk, &id->clk_rate_change_nb);
1002 clk_disable_unprepare(id->clk);
1003 pm_runtime_disable(&pdev->dev);
1004
1005 return 0;
1006 }
1007
1008 static struct platform_driver cdns_i2c_drv = {
1009 .driver = {
1010 .name = DRIVER_NAME,
1011 .of_match_table = cdns_i2c_of_match,
1012 .pm = &cdns_i2c_dev_pm_ops,
1013 },
1014 .probe = cdns_i2c_probe,
1015 .remove = cdns_i2c_remove,
1016 };
1017
1018 module_platform_driver(cdns_i2c_drv);
1019
1020 MODULE_AUTHOR("Xilinx Inc.");
1021 MODULE_DESCRIPTION("Cadence I2C bus driver");
1022 MODULE_LICENSE("GPL");