forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathi2c-pxa.c
1383 lines (1140 loc) · 32 KB
/
i2c-pxa.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* i2c_adap_pxa.c
*
* I2C adapter for the PXA I2C bus access.
*
* Copyright (C) 2002 Intrinsyc Software Inc.
* Copyright (C) 2004-2005 Deep Blue Solutions Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* History:
* Apr 2002: Initial version [CS]
* Jun 2002: Properly separated algo/adap [FB]
* Jan 2003: Fixed several bugs concerning interrupt handling [Kai-Uwe Bloem]
* Jan 2003: added limited signal handling [Kai-Uwe Bloem]
* Sep 2004: Major rework to ensure efficient bus handling [RMK]
* Dec 2004: Added support for PXA27x and slave device probing [Liam Girdwood]
* Feb 2005: Rework slave mode handling [RMK]
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/i2c-pxa.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/i2c/pxa-i2c.h>
#include <asm/irq.h>
struct pxa_reg_layout {
u32 ibmr;
u32 idbr;
u32 icr;
u32 isr;
u32 isar;
u32 ilcr;
u32 iwcr;
};
enum pxa_i2c_types {
REGS_PXA2XX,
REGS_PXA3XX,
REGS_CE4100,
REGS_PXA910,
};
/*
* I2C registers definitions
*/
static struct pxa_reg_layout pxa_reg_layout[] = {
[REGS_PXA2XX] = {
.ibmr = 0x00,
.idbr = 0x08,
.icr = 0x10,
.isr = 0x18,
.isar = 0x20,
},
[REGS_PXA3XX] = {
.ibmr = 0x00,
.idbr = 0x04,
.icr = 0x08,
.isr = 0x0c,
.isar = 0x10,
},
[REGS_CE4100] = {
.ibmr = 0x14,
.idbr = 0x0c,
.icr = 0x00,
.isr = 0x04,
/* no isar register */
},
[REGS_PXA910] = {
.ibmr = 0x00,
.idbr = 0x08,
.icr = 0x10,
.isr = 0x18,
.isar = 0x20,
.ilcr = 0x28,
.iwcr = 0x30,
},
};
static const struct platform_device_id i2c_pxa_id_table[] = {
{ "pxa2xx-i2c", REGS_PXA2XX },
{ "pxa3xx-pwri2c", REGS_PXA3XX },
{ "ce4100-i2c", REGS_CE4100 },
{ "pxa910-i2c", REGS_PXA910 },
{ },
};
MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
/*
* I2C bit definitions
*/
#define ICR_START (1 << 0) /* start bit */
#define ICR_STOP (1 << 1) /* stop bit */
#define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
#define ICR_TB (1 << 3) /* transfer byte bit */
#define ICR_MA (1 << 4) /* master abort */
#define ICR_SCLE (1 << 5) /* master clock enable */
#define ICR_IUE (1 << 6) /* unit enable */
#define ICR_GCD (1 << 7) /* general call disable */
#define ICR_ITEIE (1 << 8) /* enable tx interrupts */
#define ICR_IRFIE (1 << 9) /* enable rx interrupts */
#define ICR_BEIE (1 << 10) /* enable bus error ints */
#define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
#define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
#define ICR_SADIE (1 << 13) /* slave address detected int enable */
#define ICR_UR (1 << 14) /* unit reset */
#define ICR_FM (1 << 15) /* fast mode */
#define ICR_HS (1 << 16) /* High Speed mode */
#define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */
#define ISR_RWM (1 << 0) /* read/write mode */
#define ISR_ACKNAK (1 << 1) /* ack/nak status */
#define ISR_UB (1 << 2) /* unit busy */
#define ISR_IBB (1 << 3) /* bus busy */
#define ISR_SSD (1 << 4) /* slave stop detected */
#define ISR_ALD (1 << 5) /* arbitration loss detected */
#define ISR_ITE (1 << 6) /* tx buffer empty */
#define ISR_IRF (1 << 7) /* rx buffer full */
#define ISR_GCAD (1 << 8) /* general call address detected */
#define ISR_SAD (1 << 9) /* slave address detected */
#define ISR_BED (1 << 10) /* bus error no ACK/NAK */
/* bit field shift & mask */
#define ILCR_SLV_SHIFT 0
#define ILCR_SLV_MASK (0x1FF << ILCR_SLV_SHIFT)
#define ILCR_FLV_SHIFT 9
#define ILCR_FLV_MASK (0x1FF << ILCR_FLV_SHIFT)
#define ILCR_HLVL_SHIFT 18
#define ILCR_HLVL_MASK (0x1FF << ILCR_HLVL_SHIFT)
#define ILCR_HLVH_SHIFT 27
#define ILCR_HLVH_MASK (0x1F << ILCR_HLVH_SHIFT)
#define IWCR_CNT_SHIFT 0
#define IWCR_CNT_MASK (0x1F << IWCR_CNT_SHIFT)
#define IWCR_HS_CNT1_SHIFT 5
#define IWCR_HS_CNT1_MASK (0x1F << IWCR_HS_CNT1_SHIFT)
#define IWCR_HS_CNT2_SHIFT 10
#define IWCR_HS_CNT2_MASK (0x1F << IWCR_HS_CNT2_SHIFT)
struct pxa_i2c {
spinlock_t lock;
wait_queue_head_t wait;
struct i2c_msg *msg;
unsigned int msg_num;
unsigned int msg_idx;
unsigned int msg_ptr;
unsigned int slave_addr;
unsigned int req_slave_addr;
struct i2c_adapter adap;
struct clk *clk;
#ifdef CONFIG_I2C_PXA_SLAVE
struct i2c_slave_client *slave;
#endif
unsigned int irqlogidx;
u32 isrlog[32];
u32 icrlog[32];
void __iomem *reg_base;
void __iomem *reg_ibmr;
void __iomem *reg_idbr;
void __iomem *reg_icr;
void __iomem *reg_isr;
void __iomem *reg_isar;
void __iomem *reg_ilcr;
void __iomem *reg_iwcr;
unsigned long iobase;
unsigned long iosize;
int irq;
unsigned int use_pio :1;
unsigned int fast_mode :1;
unsigned int high_mode:1;
unsigned char master_code;
unsigned long rate;
bool highmode_enter;
};
#define _IBMR(i2c) ((i2c)->reg_ibmr)
#define _IDBR(i2c) ((i2c)->reg_idbr)
#define _ICR(i2c) ((i2c)->reg_icr)
#define _ISR(i2c) ((i2c)->reg_isr)
#define _ISAR(i2c) ((i2c)->reg_isar)
#define _ILCR(i2c) ((i2c)->reg_ilcr)
#define _IWCR(i2c) ((i2c)->reg_iwcr)
/*
* I2C Slave mode address
*/
#define I2C_PXA_SLAVE_ADDR 0x1
#ifdef DEBUG
struct bits {
u32 mask;
const char *set;
const char *unset;
};
#define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
static inline void
decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
{
printk("%s %08x: ", prefix, val);
while (num--) {
const char *str = val & bits->mask ? bits->set : bits->unset;
if (str)
printk("%s ", str);
bits++;
}
}
static const struct bits isr_bits[] = {
PXA_BIT(ISR_RWM, "RX", "TX"),
PXA_BIT(ISR_ACKNAK, "NAK", "ACK"),
PXA_BIT(ISR_UB, "Bsy", "Rdy"),
PXA_BIT(ISR_IBB, "BusBsy", "BusRdy"),
PXA_BIT(ISR_SSD, "SlaveStop", NULL),
PXA_BIT(ISR_ALD, "ALD", NULL),
PXA_BIT(ISR_ITE, "TxEmpty", NULL),
PXA_BIT(ISR_IRF, "RxFull", NULL),
PXA_BIT(ISR_GCAD, "GenCall", NULL),
PXA_BIT(ISR_SAD, "SlaveAddr", NULL),
PXA_BIT(ISR_BED, "BusErr", NULL),
};
static void decode_ISR(unsigned int val)
{
decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
printk("\n");
}
static const struct bits icr_bits[] = {
PXA_BIT(ICR_START, "START", NULL),
PXA_BIT(ICR_STOP, "STOP", NULL),
PXA_BIT(ICR_ACKNAK, "ACKNAK", NULL),
PXA_BIT(ICR_TB, "TB", NULL),
PXA_BIT(ICR_MA, "MA", NULL),
PXA_BIT(ICR_SCLE, "SCLE", "scle"),
PXA_BIT(ICR_IUE, "IUE", "iue"),
PXA_BIT(ICR_GCD, "GCD", NULL),
PXA_BIT(ICR_ITEIE, "ITEIE", NULL),
PXA_BIT(ICR_IRFIE, "IRFIE", NULL),
PXA_BIT(ICR_BEIE, "BEIE", NULL),
PXA_BIT(ICR_SSDIE, "SSDIE", NULL),
PXA_BIT(ICR_ALDIE, "ALDIE", NULL),
PXA_BIT(ICR_SADIE, "SADIE", NULL),
PXA_BIT(ICR_UR, "UR", "ur"),
};
#ifdef CONFIG_I2C_PXA_SLAVE
static void decode_ICR(unsigned int val)
{
decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
printk("\n");
}
#endif
static unsigned int i2c_debug = DEBUG;
static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
{
dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
}
#define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
{
unsigned int i;
struct device *dev = &i2c->adap.dev;
dev_err(dev, "slave_0x%x error: %s\n",
i2c->req_slave_addr >> 1, why);
dev_err(dev, "msg_num: %d msg_idx: %d msg_ptr: %d\n",
i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
dev_err(dev, "IBMR: %08x IDBR: %08x ICR: %08x ISR: %08x\n",
readl(_IBMR(i2c)), readl(_IDBR(i2c)), readl(_ICR(i2c)),
readl(_ISR(i2c)));
dev_dbg(dev, "log: ");
for (i = 0; i < i2c->irqlogidx; i++)
pr_debug("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
pr_debug("\n");
}
#else /* ifdef DEBUG */
#define i2c_debug 0
#define show_state(i2c) do { } while (0)
#define decode_ISR(val) do { } while (0)
#define decode_ICR(val) do { } while (0)
#define i2c_pxa_scream_blue_murder(i2c, why) do { } while (0)
#endif /* ifdef DEBUG / else */
static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
{
return !(readl(_ICR(i2c)) & ICR_SCLE);
}
static void i2c_pxa_abort(struct pxa_i2c *i2c)
{
int i = 250;
if (i2c_pxa_is_slavemode(i2c)) {
dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
return;
}
while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
unsigned long icr = readl(_ICR(i2c));
icr &= ~ICR_START;
icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
writel(icr, _ICR(i2c));
show_state(i2c);
mdelay(1);
i --;
}
writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
_ICR(i2c));
}
static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
{
int timeout = DEF_TIMEOUT;
while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
timeout += 4;
msleep(2);
show_state(i2c);
}
if (timeout < 0)
show_state(i2c);
return timeout < 0 ? I2C_RETRY : 0;
}
static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
{
unsigned long timeout = jiffies + HZ*4;
while (time_before(jiffies, timeout)) {
if (i2c_debug > 1)
dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
__func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
if (readl(_ISR(i2c)) & ISR_SAD) {
if (i2c_debug > 0)
dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
goto out;
}
/* wait for unit and bus being not busy, and we also do a
* quick check of the i2c lines themselves to ensure they've
* gone high...
*/
if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
if (i2c_debug > 0)
dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
return 1;
}
msleep(1);
}
if (i2c_debug > 0)
dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
out:
return 0;
}
static int i2c_pxa_set_master(struct pxa_i2c *i2c)
{
if (i2c_debug)
dev_dbg(&i2c->adap.dev, "setting to bus master\n");
if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
if (!i2c_pxa_wait_master(i2c)) {
dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
return I2C_RETRY;
}
}
writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
return 0;
}
#ifdef CONFIG_I2C_PXA_SLAVE
static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
{
unsigned long timeout = jiffies + HZ*1;
/* wait for stop */
show_state(i2c);
while (time_before(jiffies, timeout)) {
if (i2c_debug > 1)
dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
__func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
(readl(_ISR(i2c)) & ISR_SAD) != 0 ||
(readl(_ICR(i2c)) & ICR_SCLE) == 0) {
if (i2c_debug > 1)
dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
return 1;
}
msleep(1);
}
if (i2c_debug > 0)
dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
return 0;
}
/*
* clear the hold on the bus, and take of anything else
* that has been configured
*/
static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
{
show_state(i2c);
if (errcode < 0) {
udelay(100); /* simple delay */
} else {
/* we need to wait for the stop condition to end */
/* if we where in stop, then clear... */
if (readl(_ICR(i2c)) & ICR_STOP) {
udelay(100);
writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
}
if (!i2c_pxa_wait_slave(i2c)) {
dev_err(&i2c->adap.dev, "%s: wait timedout\n",
__func__);
return;
}
}
writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
if (i2c_debug) {
dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
decode_ICR(readl(_ICR(i2c)));
}
}
#else
#define i2c_pxa_set_slave(i2c, err) do { } while (0)
#endif
static void i2c_pxa_reset(struct pxa_i2c *i2c)
{
pr_debug("Resetting I2C Controller Unit\n");
/* abort any transfer currently under way */
i2c_pxa_abort(i2c);
/* reset according to 9.8 */
writel(ICR_UR, _ICR(i2c));
writel(I2C_ISR_INIT, _ISR(i2c));
writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
if (i2c->reg_isar && IS_ENABLED(CONFIG_I2C_PXA_SLAVE))
writel(i2c->slave_addr, _ISAR(i2c));
/* set control register values */
writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
writel(readl(_ICR(i2c)) | (i2c->high_mode ? ICR_HS : 0), _ICR(i2c));
#ifdef CONFIG_I2C_PXA_SLAVE
dev_info(&i2c->adap.dev, "Enabling slave mode\n");
writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
#endif
i2c_pxa_set_slave(i2c, 0);
/* enable unit */
writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
udelay(100);
}
#ifdef CONFIG_I2C_PXA_SLAVE
/*
* PXA I2C Slave mode
*/
static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
{
if (isr & ISR_BED) {
/* what should we do here? */
} else {
int ret = 0;
if (i2c->slave != NULL)
ret = i2c->slave->read(i2c->slave->data);
writel(ret, _IDBR(i2c));
writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */
}
}
static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
{
unsigned int byte = readl(_IDBR(i2c));
if (i2c->slave != NULL)
i2c->slave->write(i2c->slave->data, byte);
writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
}
static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
{
int timeout;
if (i2c_debug > 0)
dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
(isr & ISR_RWM) ? 'r' : 't');
if (i2c->slave != NULL)
i2c->slave->event(i2c->slave->data,
(isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
/*
* slave could interrupt in the middle of us generating a
* start condition... if this happens, we'd better back off
* and stop holding the poor thing up
*/
writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
timeout = 0x10000;
while (1) {
if ((readl(_IBMR(i2c)) & 2) == 2)
break;
timeout--;
if (timeout <= 0) {
dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
break;
}
}
writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
}
static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
{
if (i2c_debug > 2)
dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
if (i2c->slave != NULL)
i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
if (i2c_debug > 2)
dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
/*
* If we have a master-mode message waiting,
* kick it off now that the slave has completed.
*/
if (i2c->msg)
i2c_pxa_master_complete(i2c, I2C_RETRY);
}
#else
static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
{
if (isr & ISR_BED) {
/* what should we do here? */
} else {
writel(0, _IDBR(i2c));
writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
}
}
static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
{
writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
}
static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
{
int timeout;
/*
* slave could interrupt in the middle of us generating a
* start condition... if this happens, we'd better back off
* and stop holding the poor thing up
*/
writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
timeout = 0x10000;
while (1) {
if ((readl(_IBMR(i2c)) & 2) == 2)
break;
timeout--;
if (timeout <= 0) {
dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
break;
}
}
writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
}
static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
{
if (i2c->msg)
i2c_pxa_master_complete(i2c, I2C_RETRY);
}
#endif
/*
* PXA I2C Master mode
*/
static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
{
unsigned int addr = (msg->addr & 0x7f) << 1;
if (msg->flags & I2C_M_RD)
addr |= 1;
return addr;
}
static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
{
u32 icr;
/*
* Step 1: target slave address into IDBR
*/
writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
i2c->req_slave_addr = i2c_pxa_addr_byte(i2c->msg);
/*
* Step 2: initiate the write.
*/
icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
writel(icr | ICR_START | ICR_TB, _ICR(i2c));
}
static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
{
u32 icr;
/*
* Clear the STOP and ACK flags
*/
icr = readl(_ICR(i2c));
icr &= ~(ICR_STOP | ICR_ACKNAK);
writel(icr, _ICR(i2c));
}
static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
{
/* make timeout the same as for interrupt based functions */
long timeout = 2 * DEF_TIMEOUT;
/*
* Wait for the bus to become free.
*/
while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
udelay(1000);
show_state(i2c);
}
if (timeout < 0) {
show_state(i2c);
dev_err(&i2c->adap.dev,
"i2c_pxa: timeout waiting for bus free\n");
return I2C_RETRY;
}
/*
* Set master mode.
*/
writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
return 0;
}
/*
* PXA I2C send master code
* 1. Load master code to IDBR and send it.
* Note for HS mode, set ICR [GPIOEN].
* 2. Wait until win arbitration.
*/
static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c)
{
u32 icr;
long timeout;
spin_lock_irq(&i2c->lock);
i2c->highmode_enter = true;
writel(i2c->master_code, _IDBR(i2c));
icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
icr |= ICR_GPIOEN | ICR_START | ICR_TB | ICR_ITEIE;
writel(icr, _ICR(i2c));
spin_unlock_irq(&i2c->lock);
timeout = wait_event_timeout(i2c->wait,
i2c->highmode_enter == false, HZ * 1);
i2c->highmode_enter = false;
return (timeout == 0) ? I2C_RETRY : 0;
}
static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
struct i2c_msg *msg, int num)
{
unsigned long timeout = 500000; /* 5 seconds */
int ret = 0;
ret = i2c_pxa_pio_set_master(i2c);
if (ret)
goto out;
i2c->msg = msg;
i2c->msg_num = num;
i2c->msg_idx = 0;
i2c->msg_ptr = 0;
i2c->irqlogidx = 0;
i2c_pxa_start_message(i2c);
while (i2c->msg_num > 0 && --timeout) {
i2c_pxa_handler(0, i2c);
udelay(10);
}
i2c_pxa_stop_message(i2c);
/*
* We place the return code in i2c->msg_idx.
*/
ret = i2c->msg_idx;
out:
if (timeout == 0) {
i2c_pxa_scream_blue_murder(i2c, "timeout");
ret = I2C_RETRY;
}
return ret;
}
/*
* We are protected by the adapter bus mutex.
*/
static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
{
long timeout;
int ret;
/*
* Wait for the bus to become free.
*/
ret = i2c_pxa_wait_bus_not_busy(i2c);
if (ret) {
dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
goto out;
}
/*
* Set master mode.
*/
ret = i2c_pxa_set_master(i2c);
if (ret) {
dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
goto out;
}
if (i2c->high_mode) {
ret = i2c_pxa_send_mastercode(i2c);
if (ret) {
dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
goto out;
}
}
spin_lock_irq(&i2c->lock);
i2c->msg = msg;
i2c->msg_num = num;
i2c->msg_idx = 0;
i2c->msg_ptr = 0;
i2c->irqlogidx = 0;
i2c_pxa_start_message(i2c);
spin_unlock_irq(&i2c->lock);
/*
* The rest of the processing occurs in the interrupt handler.
*/
timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
i2c_pxa_stop_message(i2c);
/*
* We place the return code in i2c->msg_idx.
*/
ret = i2c->msg_idx;
if (!timeout && i2c->msg_num) {
i2c_pxa_scream_blue_murder(i2c, "timeout");
ret = I2C_RETRY;
}
out:
return ret;
}
static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
struct i2c_msg msgs[], int num)
{
struct pxa_i2c *i2c = adap->algo_data;
int ret, i;
/* If the I2C controller is disabled we need to reset it
(probably due to a suspend/resume destroying state). We do
this here as we can then avoid worrying about resuming the
controller before its users. */
if (!(readl(_ICR(i2c)) & ICR_IUE))
i2c_pxa_reset(i2c);
for (i = adap->retries; i >= 0; i--) {
ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
if (ret != I2C_RETRY)
goto out;
if (i2c_debug)
dev_dbg(&adap->dev, "Retrying transmission\n");
udelay(100);
}
i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
ret = -EREMOTEIO;
out:
i2c_pxa_set_slave(i2c, ret);
return ret;
}
/*
* i2c_pxa_master_complete - complete the message and wake up.
*/
static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
{
i2c->msg_ptr = 0;
i2c->msg = NULL;
i2c->msg_idx ++;
i2c->msg_num = 0;
if (ret)
i2c->msg_idx = ret;
if (!i2c->use_pio)
wake_up(&i2c->wait);
}
static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
{
u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
again:
/*
* If ISR_ALD is set, we lost arbitration.
*/
if (isr & ISR_ALD) {
/*
* Do we need to do anything here? The PXA docs
* are vague about what happens.
*/
i2c_pxa_scream_blue_murder(i2c, "ALD set");
/*
* We ignore this error. We seem to see spurious ALDs
* for seemingly no reason. If we handle them as I think
* they should, we end up causing an I2C error, which
* is painful for some systems.
*/
return; /* ignore */
}
if ((isr & ISR_BED) &&
(!((i2c->msg->flags & I2C_M_IGNORE_NAK) &&
(isr & ISR_ACKNAK)))) {
int ret = BUS_ERROR;
/*
* I2C bus error - either the device NAK'd us, or
* something more serious happened. If we were NAK'd
* on the initial address phase, we can retry.
*/
if (isr & ISR_ACKNAK) {
if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
ret = I2C_RETRY;
else
ret = XFER_NAKED;
}
i2c_pxa_master_complete(i2c, ret);
} else if (isr & ISR_RWM) {
/*
* Read mode. We have just sent the address byte, and
* now we must initiate the transfer.
*/
if (i2c->msg_ptr == i2c->msg->len - 1 &&
i2c->msg_idx == i2c->msg_num - 1)
icr |= ICR_STOP | ICR_ACKNAK;
icr |= ICR_ALDIE | ICR_TB;
} else if (i2c->msg_ptr < i2c->msg->len) {
/*
* Write mode. Write the next data byte.
*/
writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
icr |= ICR_ALDIE | ICR_TB;
/*
* If this is the last byte of the last message or last byte
* of any message with I2C_M_STOP (e.g. SCCB), send a STOP.
*/
if ((i2c->msg_ptr == i2c->msg->len) &&
((i2c->msg->flags & I2C_M_STOP) ||
(i2c->msg_idx == i2c->msg_num - 1)))
icr |= ICR_STOP;
} else if (i2c->msg_idx < i2c->msg_num - 1) {
/*
* Next segment of the message.
*/
i2c->msg_ptr = 0;
i2c->msg_idx ++;
i2c->msg++;
/*
* If we aren't doing a repeated start and address,
* go back and try to send the next byte. Note that
* we do not support switching the R/W direction here.
*/
if (i2c->msg->flags & I2C_M_NOSTART)
goto again;
/*
* Write the next address.
*/
writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
i2c->req_slave_addr = i2c_pxa_addr_byte(i2c->msg);
/*
* And trigger a repeated start, and send the byte.
*/
icr &= ~ICR_ALDIE;