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-rw-r--r--drivers/i2c/busses/i2c-pxa.c1031
1 files changed, 1031 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
new file mode 100644
index 000000000000..a72d28365297
--- /dev/null
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -0,0 +1,1031 @@
1/*
2 * i2c_adap_pxa.c
3 *
4 * I2C adapter for the PXA I2C bus access.
5 *
6 * Copyright (C) 2002 Intrinsyc Software Inc.
7 * Copyright (C) 2004-2005 Deep Blue Solutions Ltd.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * History:
14 * Apr 2002: Initial version [CS]
15 * Jun 2002: Properly seperated algo/adap [FB]
16 * Jan 2003: Fixed several bugs concerning interrupt handling [Kai-Uwe Bloem]
17 * Jan 2003: added limited signal handling [Kai-Uwe Bloem]
18 * Sep 2004: Major rework to ensure efficient bus handling [RMK]
19 * Dec 2004: Added support for PXA27x and slave device probing [Liam Girdwood]
20 * Feb 2005: Rework slave mode handling [RMK]
21 */
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/i2c.h>
25#include <linux/i2c-id.h>
26#include <linux/init.h>
27#include <linux/time.h>
28#include <linux/sched.h>
29#include <linux/delay.h>
30#include <linux/errno.h>
31#include <linux/interrupt.h>
32#include <linux/i2c-pxa.h>
33
34#include <asm/hardware.h>
35#include <asm/irq.h>
36#include <asm/arch/i2c.h>
37#include <asm/arch/pxa-regs.h>
38
39struct pxa_i2c {
40 spinlock_t lock;
41 wait_queue_head_t wait;
42 struct i2c_msg *msg;
43 unsigned int msg_num;
44 unsigned int msg_idx;
45 unsigned int msg_ptr;
46 unsigned int slave_addr;
47
48 struct i2c_adapter adap;
49#ifdef CONFIG_I2C_PXA_SLAVE
50 struct i2c_slave_client *slave;
51#endif
52
53 unsigned int irqlogidx;
54 u32 isrlog[32];
55 u32 icrlog[32];
56};
57
58/*
59 * I2C Slave mode address
60 */
61#define I2C_PXA_SLAVE_ADDR 0x1
62
63/*
64 * Set this to zero to remove all debug statements via dead code elimination.
65 */
66#undef DEBUG
67
68#if 0
69#define DBGLVL KERN_INFO
70#else
71#define DBGLVL KERN_DEBUG
72#endif
73
74#ifdef DEBUG
75
76struct bits {
77 u32 mask;
78 const char *set;
79 const char *unset;
80};
81#define BIT(m, s, u) { .mask = m, .set = s, .unset = u }
82
83static inline void
84decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
85{
86 printk("%s %08x: ", prefix, val);
87 while (num--) {
88 const char *str = val & bits->mask ? bits->set : bits->unset;
89 if (str)
90 printk("%s ", str);
91 bits++;
92 }
93}
94
95static const struct bits isr_bits[] = {
96 BIT(ISR_RWM, "RX", "TX"),
97 BIT(ISR_ACKNAK, "NAK", "ACK"),
98 BIT(ISR_UB, "Bsy", "Rdy"),
99 BIT(ISR_IBB, "BusBsy", "BusRdy"),
100 BIT(ISR_SSD, "SlaveStop", NULL),
101 BIT(ISR_ALD, "ALD", NULL),
102 BIT(ISR_ITE, "TxEmpty", NULL),
103 BIT(ISR_IRF, "RxFull", NULL),
104 BIT(ISR_GCAD, "GenCall", NULL),
105 BIT(ISR_SAD, "SlaveAddr", NULL),
106 BIT(ISR_BED, "BusErr", NULL),
107};
108
109static void decode_ISR(unsigned int val)
110{
111 decode_bits(DBGLVL "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
112 printk("\n");
113}
114
115static const struct bits icr_bits[] = {
116 BIT(ICR_START, "START", NULL),
117 BIT(ICR_STOP, "STOP", NULL),
118 BIT(ICR_ACKNAK, "ACKNAK", NULL),
119 BIT(ICR_TB, "TB", NULL),
120 BIT(ICR_MA, "MA", NULL),
121 BIT(ICR_SCLE, "SCLE", "scle"),
122 BIT(ICR_IUE, "IUE", "iue"),
123 BIT(ICR_GCD, "GCD", NULL),
124 BIT(ICR_ITEIE, "ITEIE", NULL),
125 BIT(ICR_IRFIE, "IRFIE", NULL),
126 BIT(ICR_BEIE, "BEIE", NULL),
127 BIT(ICR_SSDIE, "SSDIE", NULL),
128 BIT(ICR_ALDIE, "ALDIE", NULL),
129 BIT(ICR_SADIE, "SADIE", NULL),
130 BIT(ICR_UR, "UR", "ur"),
131};
132
133static void decode_ICR(unsigned int val)
134{
135 decode_bits(DBGLVL "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
136 printk("\n");
137}
138
139static unsigned int i2c_debug = DEBUG;
140
141static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
142{
143 printk(DBGLVL "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno, ISR, ICR, IBMR);
144}
145
146#define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __FUNCTION__)
147#else
148#define i2c_debug 0
149
150#define show_state(i2c) do { } while (0)
151#define decode_ISR(val) do { } while (0)
152#define decode_ICR(val) do { } while (0)
153#endif
154
155#define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(DBGLVL "" x); } } while(0)
156
157static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
158
159static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
160{
161 unsigned int i;
162 printk("i2c: error: %s\n", why);
163 printk("i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
164 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
165 printk("i2c: ICR: %08x ISR: %08x\ni2c: log: ", ICR, ISR);
166 for (i = 0; i < i2c->irqlogidx; i++)
167 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
168 printk("\n");
169}
170
171static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
172{
173 return !(ICR & ICR_SCLE);
174}
175
176static void i2c_pxa_abort(struct pxa_i2c *i2c)
177{
178 unsigned long timeout = jiffies + HZ/4;
179
180 if (i2c_pxa_is_slavemode(i2c)) {
181 printk(DBGLVL "i2c_pxa_transfer: called in slave mode\n");
182 return;
183 }
184
185 while (time_before(jiffies, timeout) && (IBMR & 0x1) == 0) {
186 unsigned long icr = ICR;
187
188 icr &= ~ICR_START;
189 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
190
191 ICR = icr;
192
193 show_state(i2c);
194
195 msleep(1);
196 }
197
198 ICR &= ~(ICR_MA | ICR_START | ICR_STOP);
199}
200
201static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
202{
203 int timeout = DEF_TIMEOUT;
204
205 while (timeout-- && ISR & (ISR_IBB | ISR_UB)) {
206 if ((ISR & ISR_SAD) != 0)
207 timeout += 4;
208
209 msleep(2);
210 show_state(i2c);
211 }
212
213 if (timeout <= 0)
214 show_state(i2c);
215
216 return timeout <= 0 ? I2C_RETRY : 0;
217}
218
219static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
220{
221 unsigned long timeout = jiffies + HZ*4;
222
223 while (time_before(jiffies, timeout)) {
224 if (i2c_debug > 1)
225 printk(DBGLVL "i2c_pxa_wait_master: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
226 (long)jiffies, ISR, ICR, IBMR);
227
228 if (ISR & ISR_SAD) {
229 if (i2c_debug > 0)
230 printk(DBGLVL "i2c_pxa_wait_master: Slave detected\n");
231 goto out;
232 }
233
234 /* wait for unit and bus being not busy, and we also do a
235 * quick check of the i2c lines themselves to ensure they've
236 * gone high...
237 */
238 if ((ISR & (ISR_UB | ISR_IBB)) == 0 && IBMR == 3) {
239 if (i2c_debug > 0)
240 printk(DBGLVL "i2c_pxa_wait_master: done\n");
241 return 1;
242 }
243
244 msleep(1);
245 }
246
247 if (i2c_debug > 0)
248 printk(DBGLVL "i2c_pxa_wait_master: did not free\n");
249 out:
250 return 0;
251}
252
253static int i2c_pxa_set_master(struct pxa_i2c *i2c)
254{
255 if (i2c_debug)
256 printk(DBGLVL "I2C: setting to bus master\n");
257
258 if ((ISR & (ISR_UB | ISR_IBB)) != 0) {
259 printk(DBGLVL "set_master: unit is busy\n");
260 if (!i2c_pxa_wait_master(i2c)) {
261 printk(DBGLVL "set_master: error: unit busy\n");
262 return I2C_RETRY;
263 }
264 }
265
266 ICR |= ICR_SCLE;
267 return 0;
268}
269
270#ifdef CONFIG_I2C_PXA_SLAVE
271static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
272{
273 unsigned long timeout = jiffies + HZ*1;
274
275 /* wait for stop */
276
277 show_state(i2c);
278
279 while (time_before(jiffies, timeout)) {
280 if (i2c_debug > 1)
281 printk(DBGLVL "i2c_pxa_wait_slave: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
282 (long)jiffies, ISR, ICR, IBMR);
283
284 if ((ISR & (ISR_UB|ISR_IBB|ISR_SAD)) == ISR_SAD ||
285 (ICR & ICR_SCLE) == 0) {
286 if (i2c_debug > 1)
287 printk(DBGLVL "i2c_pxa_wait_slave: done\n");
288 return 1;
289 }
290
291 msleep(1);
292 }
293
294 if (i2c_debug > 0)
295 printk(DBGLVL "i2c_pxa_wait_slave: did not free\n");
296 return 0;
297}
298
299/*
300 * clear the hold on the bus, and take of anything else
301 * that has been configured
302 */
303static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
304{
305 show_state(i2c);
306
307 if (errcode < 0) {
308 udelay(100); /* simple delay */
309 } else {
310 /* we need to wait for the stop condition to end */
311
312 /* if we where in stop, then clear... */
313 if (ICR & ICR_STOP) {
314 udelay(100);
315 ICR &= ~ICR_STOP;
316 }
317
318 if (!i2c_pxa_wait_slave(i2c)) {
319 printk(KERN_ERR "i2c_pxa_set_slave: wait timedout\n");
320 return;
321 }
322 }
323
324 ICR &= ~(ICR_STOP|ICR_ACKNAK|ICR_MA);
325 ICR &= ~ICR_SCLE;
326
327 if (i2c_debug) {
328 printk(DBGLVL "ICR now %08x, ISR %08x\n", ICR, ISR);
329 decode_ICR(ICR);
330 }
331}
332#else
333#define i2c_pxa_set_slave(i2c, err) do { } while (0)
334#endif
335
336static void i2c_pxa_reset(struct pxa_i2c *i2c)
337{
338 pr_debug("Resetting I2C Controller Unit\n");
339
340 /* abort any transfer currently under way */
341 i2c_pxa_abort(i2c);
342
343 /* reset according to 9.8 */
344 ICR = ICR_UR;
345 ISR = I2C_ISR_INIT;
346 ICR &= ~ICR_UR;
347
348 ISAR = i2c->slave_addr;
349
350 /* set control register values */
351 ICR = I2C_ICR_INIT;
352
353#ifdef CONFIG_I2C_PXA_SLAVE
354 printk(KERN_INFO "I2C: Enabling slave mode\n");
355 ICR |= ICR_SADIE | ICR_ALDIE | ICR_SSDIE;
356#endif
357
358 i2c_pxa_set_slave(i2c, 0);
359
360 /* enable unit */
361 ICR |= ICR_IUE;
362 udelay(100);
363}
364
365
366#ifdef CONFIG_I2C_PXA_SLAVE
367/*
368 * I2C EEPROM emulation.
369 */
370static struct i2c_eeprom_emu eeprom = {
371 .size = I2C_EEPROM_EMU_SIZE,
372 .watch = LIST_HEAD_INIT(eeprom.watch),
373};
374
375struct i2c_eeprom_emu *i2c_pxa_get_eeprom(void)
376{
377 return &eeprom;
378}
379
380int i2c_eeprom_emu_addwatcher(struct i2c_eeprom_emu *emu, void *data,
381 unsigned int addr, unsigned int size,
382 struct i2c_eeprom_emu_watcher *watcher)
383{
384 struct i2c_eeprom_emu_watch *watch;
385 unsigned long flags;
386
387 if (addr + size > emu->size)
388 return -EINVAL;
389
390 watch = kmalloc(sizeof(struct i2c_eeprom_emu_watch), GFP_KERNEL);
391 if (watch) {
392 watch->start = addr;
393 watch->end = addr + size - 1;
394 watch->ops = watcher;
395 watch->data = data;
396
397 local_irq_save(flags);
398 list_add(&watch->node, &emu->watch);
399 local_irq_restore(flags);
400 }
401
402 return watch ? 0 : -ENOMEM;
403}
404
405void i2c_eeprom_emu_delwatcher(struct i2c_eeprom_emu *emu, void *data,
406 struct i2c_eeprom_emu_watcher *watcher)
407{
408 struct i2c_eeprom_emu_watch *watch, *n;
409 unsigned long flags;
410
411 list_for_each_entry_safe(watch, n, &emu->watch, node) {
412 if (watch->ops == watcher && watch->data == data) {
413 local_irq_save(flags);
414 list_del(&watch->node);
415 local_irq_restore(flags);
416 kfree(watch);
417 }
418 }
419}
420
421static void i2c_eeprom_emu_event(void *ptr, i2c_slave_event_t event)
422{
423 struct i2c_eeprom_emu *emu = ptr;
424
425 eedbg(3, "i2c_eeprom_emu_event: %d\n", event);
426
427 switch (event) {
428 case I2C_SLAVE_EVENT_START_WRITE:
429 emu->seen_start = 1;
430 eedbg(2, "i2c_eeprom: write initiated\n");
431 break;
432
433 case I2C_SLAVE_EVENT_START_READ:
434 emu->seen_start = 0;
435 eedbg(2, "i2c_eeprom: read initiated\n");
436 break;
437
438 case I2C_SLAVE_EVENT_STOP:
439 emu->seen_start = 0;
440 eedbg(2, "i2c_eeprom: received stop\n");
441 break;
442
443 default:
444 eedbg(0, "i2c_eeprom: unhandled event\n");
445 break;
446 }
447}
448
449static int i2c_eeprom_emu_read(void *ptr)
450{
451 struct i2c_eeprom_emu *emu = ptr;
452 int ret;
453
454 ret = emu->bytes[emu->ptr];
455 emu->ptr = (emu->ptr + 1) % emu->size;
456
457 return ret;
458}
459
460static void i2c_eeprom_emu_write(void *ptr, unsigned int val)
461{
462 struct i2c_eeprom_emu *emu = ptr;
463 struct i2c_eeprom_emu_watch *watch;
464
465 if (emu->seen_start != 0) {
466 eedbg(2, "i2c_eeprom_emu_write: setting ptr %02x\n", val);
467 emu->ptr = val;
468 emu->seen_start = 0;
469 return;
470 }
471
472 emu->bytes[emu->ptr] = val;
473
474 eedbg(1, "i2c_eeprom_emu_write: ptr=0x%02x, val=0x%02x\n",
475 emu->ptr, val);
476
477 list_for_each_entry(watch, &emu->watch, node) {
478 if (!watch->ops || !watch->ops->write)
479 continue;
480 if (watch->start <= emu->ptr && watch->end >= emu->ptr)
481 watch->ops->write(watch->data, emu->ptr, val);
482 }
483
484 emu->ptr = (emu->ptr + 1) % emu->size;
485}
486
487struct i2c_slave_client eeprom_client = {
488 .data = &eeprom,
489 .event = i2c_eeprom_emu_event,
490 .read = i2c_eeprom_emu_read,
491 .write = i2c_eeprom_emu_write
492};
493
494/*
495 * PXA I2C Slave mode
496 */
497
498static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
499{
500 if (isr & ISR_BED) {
501 /* what should we do here? */
502 } else {
503 int ret = i2c->slave->read(i2c->slave->data);
504
505 IDBR = ret;
506 ICR |= ICR_TB; /* allow next byte */
507 }
508}
509
510static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
511{
512 unsigned int byte = IDBR;
513
514 if (i2c->slave != NULL)
515 i2c->slave->write(i2c->slave->data, byte);
516
517 ICR |= ICR_TB;
518}
519
520static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
521{
522 int timeout;
523
524 if (i2c_debug > 0)
525 printk(DBGLVL "I2C: SAD, mode is slave-%cx\n",
526 (isr & ISR_RWM) ? 'r' : 't');
527
528 if (i2c->slave != NULL)
529 i2c->slave->event(i2c->slave->data,
530 (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
531
532 /*
533 * slave could interrupt in the middle of us generating a
534 * start condition... if this happens, we'd better back off
535 * and stop holding the poor thing up
536 */
537 ICR &= ~(ICR_START|ICR_STOP);
538 ICR |= ICR_TB;
539
540 timeout = 0x10000;
541
542 while (1) {
543 if ((IBMR & 2) == 2)
544 break;
545
546 timeout--;
547
548 if (timeout <= 0) {
549 printk(KERN_ERR "timeout waiting for SCL high\n");
550 break;
551 }
552 }
553
554 ICR &= ~ICR_SCLE;
555}
556
557static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
558{
559 if (i2c_debug > 2)
560 printk(DBGLVL "ISR: SSD (Slave Stop)\n");
561
562 if (i2c->slave != NULL)
563 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
564
565 if (i2c_debug > 2)
566 printk(DBGLVL "ISR: SSD (Slave Stop) acked\n");
567
568 /*
569 * If we have a master-mode message waiting,
570 * kick it off now that the slave has completed.
571 */
572 if (i2c->msg)
573 i2c_pxa_master_complete(i2c, I2C_RETRY);
574}
575#else
576static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
577{
578 if (isr & ISR_BED) {
579 /* what should we do here? */
580 } else {
581 IDBR = 0;
582 ICR |= ICR_TB;
583 }
584}
585
586static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
587{
588 ICR |= ICR_TB | ICR_ACKNAK;
589}
590
591static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
592{
593 int timeout;
594
595 /*
596 * slave could interrupt in the middle of us generating a
597 * start condition... if this happens, we'd better back off
598 * and stop holding the poor thing up
599 */
600 ICR &= ~(ICR_START|ICR_STOP);
601 ICR |= ICR_TB | ICR_ACKNAK;
602
603 timeout = 0x10000;
604
605 while (1) {
606 if ((IBMR & 2) == 2)
607 break;
608
609 timeout--;
610
611 if (timeout <= 0) {
612 printk(KERN_ERR "timeout waiting for SCL high\n");
613 break;
614 }
615 }
616
617 ICR &= ~ICR_SCLE;
618}
619
620static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
621{
622 if (i2c->msg)
623 i2c_pxa_master_complete(i2c, I2C_RETRY);
624}
625#endif
626
627/*
628 * PXA I2C Master mode
629 */
630
631static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
632{
633 unsigned int addr = (msg->addr & 0x7f) << 1;
634
635 if (msg->flags & I2C_M_RD)
636 addr |= 1;
637
638 return addr;
639}
640
641static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
642{
643 u32 icr;
644
645 /*
646 * Step 1: target slave address into IDBR
647 */
648 IDBR = i2c_pxa_addr_byte(i2c->msg);
649
650 /*
651 * Step 2: initiate the write.
652 */
653 icr = ICR & ~(ICR_STOP | ICR_ALDIE);
654 ICR = icr | ICR_START | ICR_TB;
655}
656
657/*
658 * We are protected by the adapter bus semaphore.
659 */
660static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
661{
662 long timeout;
663 int ret;
664
665 /*
666 * Wait for the bus to become free.
667 */
668 ret = i2c_pxa_wait_bus_not_busy(i2c);
669 if (ret) {
670 printk(KERN_INFO "i2c_pxa: timeout waiting for bus free\n");
671 goto out;
672 }
673
674 /*
675 * Set master mode.
676 */
677 ret = i2c_pxa_set_master(i2c);
678 if (ret) {
679 printk(KERN_INFO "i2c_pxa_set_master: error %d\n", ret);
680 goto out;
681 }
682
683 spin_lock_irq(&i2c->lock);
684
685 i2c->msg = msg;
686 i2c->msg_num = num;
687 i2c->msg_idx = 0;
688 i2c->msg_ptr = 0;
689 i2c->irqlogidx = 0;
690
691 i2c_pxa_start_message(i2c);
692
693 spin_unlock_irq(&i2c->lock);
694
695 /*
696 * The rest of the processing occurs in the interrupt handler.
697 */
698 timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
699
700 /*
701 * We place the return code in i2c->msg_idx.
702 */
703 ret = i2c->msg_idx;
704
705 if (timeout == 0)
706 i2c_pxa_scream_blue_murder(i2c, "timeout");
707
708 out:
709 return ret;
710}
711
712/*
713 * i2c_pxa_master_complete - complete the message and wake up.
714 */
715static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
716{
717 i2c->msg_ptr = 0;
718 i2c->msg = NULL;
719 i2c->msg_idx ++;
720 i2c->msg_num = 0;
721 if (ret)
722 i2c->msg_idx = ret;
723 wake_up(&i2c->wait);
724}
725
726static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
727{
728 u32 icr = ICR & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
729
730 again:
731 /*
732 * If ISR_ALD is set, we lost arbitration.
733 */
734 if (isr & ISR_ALD) {
735 /*
736 * Do we need to do anything here? The PXA docs
737 * are vague about what happens.
738 */
739 i2c_pxa_scream_blue_murder(i2c, "ALD set");
740
741 /*
742 * We ignore this error. We seem to see spurious ALDs
743 * for seemingly no reason. If we handle them as I think
744 * they should, we end up causing an I2C error, which
745 * is painful for some systems.
746 */
747 return; /* ignore */
748 }
749
750 if (isr & ISR_BED) {
751 int ret = BUS_ERROR;
752
753 /*
754 * I2C bus error - either the device NAK'd us, or
755 * something more serious happened. If we were NAK'd
756 * on the initial address phase, we can retry.
757 */
758 if (isr & ISR_ACKNAK) {
759 if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
760 ret = I2C_RETRY;
761 else
762 ret = XFER_NAKED;
763 }
764 i2c_pxa_master_complete(i2c, ret);
765 } else if (isr & ISR_RWM) {
766 /*
767 * Read mode. We have just sent the address byte, and
768 * now we must initiate the transfer.
769 */
770 if (i2c->msg_ptr == i2c->msg->len - 1 &&
771 i2c->msg_idx == i2c->msg_num - 1)
772 icr |= ICR_STOP | ICR_ACKNAK;
773
774 icr |= ICR_ALDIE | ICR_TB;
775 } else if (i2c->msg_ptr < i2c->msg->len) {
776 /*
777 * Write mode. Write the next data byte.
778 */
779 IDBR = i2c->msg->buf[i2c->msg_ptr++];
780
781 icr |= ICR_ALDIE | ICR_TB;
782
783 /*
784 * If this is the last byte of the last message, send
785 * a STOP.
786 */
787 if (i2c->msg_ptr == i2c->msg->len &&
788 i2c->msg_idx == i2c->msg_num - 1)
789 icr |= ICR_STOP;
790 } else if (i2c->msg_idx < i2c->msg_num - 1) {
791 /*
792 * Next segment of the message.
793 */
794 i2c->msg_ptr = 0;
795 i2c->msg_idx ++;
796 i2c->msg++;
797
798 /*
799 * If we aren't doing a repeated start and address,
800 * go back and try to send the next byte. Note that
801 * we do not support switching the R/W direction here.
802 */
803 if (i2c->msg->flags & I2C_M_NOSTART)
804 goto again;
805
806 /*
807 * Write the next address.
808 */
809 IDBR = i2c_pxa_addr_byte(i2c->msg);
810
811 /*
812 * And trigger a repeated start, and send the byte.
813 */
814 icr &= ~ICR_ALDIE;
815 icr |= ICR_START | ICR_TB;
816 } else {
817 if (i2c->msg->len == 0) {
818 /*
819 * Device probes have a message length of zero
820 * and need the bus to be reset before it can
821 * be used again.
822 */
823 i2c_pxa_reset(i2c);
824 }
825 i2c_pxa_master_complete(i2c, 0);
826 }
827
828 i2c->icrlog[i2c->irqlogidx-1] = icr;
829
830 ICR = icr;
831 show_state(i2c);
832}
833
834static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
835{
836 u32 icr = ICR & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
837
838 /*
839 * Read the byte.
840 */
841 i2c->msg->buf[i2c->msg_ptr++] = IDBR;
842
843 if (i2c->msg_ptr < i2c->msg->len) {
844 /*
845 * If this is the last byte of the last
846 * message, send a STOP.
847 */
848 if (i2c->msg_ptr == i2c->msg->len - 1)
849 icr |= ICR_STOP | ICR_ACKNAK;
850
851 icr |= ICR_ALDIE | ICR_TB;
852 } else {
853 i2c_pxa_master_complete(i2c, 0);
854 }
855
856 i2c->icrlog[i2c->irqlogidx-1] = icr;
857
858 ICR = icr;
859}
860
861static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id, struct pt_regs *regs)
862{
863 struct pxa_i2c *i2c = dev_id;
864 u32 isr = ISR;
865
866 if (i2c_debug > 2 && 0) {
867 printk(DBGLVL "i2c_pxa_handler: ISR=%08x, ICR=%08x, IBMR=%02x\n",
868 isr, ICR, IBMR);
869 decode_ISR(isr);
870 }
871
872 if (i2c->irqlogidx < sizeof(i2c->isrlog)/sizeof(u32))
873 i2c->isrlog[i2c->irqlogidx++] = isr;
874
875 show_state(i2c);
876
877 /*
878 * Always clear all pending IRQs.
879 */
880 ISR = isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED);
881
882 if (isr & ISR_SAD)
883 i2c_pxa_slave_start(i2c, isr);
884 if (isr & ISR_SSD)
885 i2c_pxa_slave_stop(i2c);
886
887 if (i2c_pxa_is_slavemode(i2c)) {
888 if (isr & ISR_ITE)
889 i2c_pxa_slave_txempty(i2c, isr);
890 if (isr & ISR_IRF)
891 i2c_pxa_slave_rxfull(i2c, isr);
892 } else if (i2c->msg) {
893 if (isr & ISR_ITE)
894 i2c_pxa_irq_txempty(i2c, isr);
895 if (isr & ISR_IRF)
896 i2c_pxa_irq_rxfull(i2c, isr);
897 } else {
898 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
899 }
900
901 return IRQ_HANDLED;
902}
903
904
905static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
906{
907 struct pxa_i2c *i2c = adap->algo_data;
908 int ret, i;
909
910 for (i = adap->retries; i >= 0; i--) {
911 ret = i2c_pxa_do_xfer(i2c, msgs, num);
912 if (ret != I2C_RETRY)
913 goto out;
914
915 if (i2c_debug)
916 printk(KERN_INFO "Retrying transmission\n");
917 udelay(100);
918 }
919 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
920 ret = -EREMOTEIO;
921 out:
922 i2c_pxa_set_slave(i2c, ret);
923 return ret;
924}
925
926static struct i2c_algorithm i2c_pxa_algorithm = {
927 .name = "PXA-I2C-Algorithm",
928 .id = I2C_ALGO_PXA,
929 .master_xfer = i2c_pxa_xfer,
930};
931
932static struct pxa_i2c i2c_pxa = {
933 .lock = SPIN_LOCK_UNLOCKED,
934 .wait = __WAIT_QUEUE_HEAD_INITIALIZER(i2c_pxa.wait),
935 .adap = {
936 .name = "pxa2xx-i2c",
937 .id = I2C_ALGO_PXA,
938 .algo = &i2c_pxa_algorithm,
939 .retries = 5,
940 },
941};
942
943static int i2c_pxa_probe(struct device *dev)
944{
945 struct pxa_i2c *i2c = &i2c_pxa;
946 struct i2c_pxa_platform_data *plat = dev->platform_data;
947 int ret;
948
949#ifdef CONFIG_PXA27x
950 pxa_gpio_mode(GPIO117_I2CSCL_MD);
951 pxa_gpio_mode(GPIO118_I2CSDA_MD);
952 udelay(100);
953#endif
954
955 i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
956
957#ifdef CONFIG_I2C_PXA_SLAVE
958 i2c->slave = &eeprom_client;
959 if (plat) {
960 i2c->slave_addr = plat->slave_addr;
961 if (plat->slave)
962 i2c->slave = plat->slave;
963 }
964#endif
965
966 pxa_set_cken(CKEN14_I2C, 1);
967 ret = request_irq(IRQ_I2C, i2c_pxa_handler, SA_INTERRUPT,
968 "pxa2xx-i2c", i2c);
969 if (ret)
970 goto out;
971
972 i2c_pxa_reset(i2c);
973
974 i2c->adap.algo_data = i2c;
975 i2c->adap.dev.parent = dev;
976
977 ret = i2c_add_adapter(&i2c->adap);
978 if (ret < 0) {
979 printk(KERN_INFO "I2C: Failed to add bus\n");
980 goto err_irq;
981 }
982
983 dev_set_drvdata(dev, i2c);
984
985#ifdef CONFIG_I2C_PXA_SLAVE
986 printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
987 i2c->adap.dev.bus_id, i2c->slave_addr);
988#else
989 printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
990 i2c->adap.dev.bus_id);
991#endif
992 return 0;
993
994 err_irq:
995 free_irq(IRQ_I2C, i2c);
996 out:
997 return ret;
998}
999
1000static int i2c_pxa_remove(struct device *dev)
1001{
1002 struct pxa_i2c *i2c = dev_get_drvdata(dev);
1003
1004 dev_set_drvdata(dev, NULL);
1005
1006 i2c_del_adapter(&i2c->adap);
1007 free_irq(IRQ_I2C, i2c);
1008 pxa_set_cken(CKEN14_I2C, 0);
1009
1010 return 0;
1011}
1012
1013static struct device_driver i2c_pxa_driver = {
1014 .name = "pxa2xx-i2c",
1015 .bus = &platform_bus_type,
1016 .probe = i2c_pxa_probe,
1017 .remove = i2c_pxa_remove,
1018};
1019
1020static int __init i2c_adap_pxa_init(void)
1021{
1022 return driver_register(&i2c_pxa_driver);
1023}
1024
1025static void i2c_adap_pxa_exit(void)
1026{
1027 return driver_unregister(&i2c_pxa_driver);
1028}
1029
1030module_init(i2c_adap_pxa_init);
1031module_exit(i2c_adap_pxa_exit);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-21 00:57:21 -0500