Merge branch 'srp' of master.kernel.org:/pub/scm/linux/kernel/git/roland/infiniband
[linux-2.6] / drivers / i2c / busses / i2c-pxa.c
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 #include <linux/platform_device.h>
34
35 #include <asm/hardware.h>
36 #include <asm/irq.h>
37 #include <asm/arch/i2c.h>
38 #include <asm/arch/pxa-regs.h>
39
40 struct pxa_i2c {
41         spinlock_t              lock;
42         wait_queue_head_t       wait;
43         struct i2c_msg          *msg;
44         unsigned int            msg_num;
45         unsigned int            msg_idx;
46         unsigned int            msg_ptr;
47         unsigned int            slave_addr;
48
49         struct i2c_adapter      adap;
50 #ifdef CONFIG_I2C_PXA_SLAVE
51         struct i2c_slave_client *slave;
52 #endif
53
54         unsigned int            irqlogidx;
55         u32                     isrlog[32];
56         u32                     icrlog[32];
57 };
58
59 /*
60  * I2C Slave mode address
61  */
62 #define I2C_PXA_SLAVE_ADDR      0x1
63
64 #ifdef DEBUG
65
66 struct bits {
67         u32     mask;
68         const char *set;
69         const char *unset;
70 };
71 #define BIT(m, s, u)    { .mask = m, .set = s, .unset = u }
72
73 static inline void
74 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
75 {
76         printk("%s %08x: ", prefix, val);
77         while (num--) {
78                 const char *str = val & bits->mask ? bits->set : bits->unset;
79                 if (str)
80                         printk("%s ", str);
81                 bits++;
82         }
83 }
84
85 static const struct bits isr_bits[] = {
86         BIT(ISR_RWM,    "RX",           "TX"),
87         BIT(ISR_ACKNAK, "NAK",          "ACK"),
88         BIT(ISR_UB,     "Bsy",          "Rdy"),
89         BIT(ISR_IBB,    "BusBsy",       "BusRdy"),
90         BIT(ISR_SSD,    "SlaveStop",    NULL),
91         BIT(ISR_ALD,    "ALD",          NULL),
92         BIT(ISR_ITE,    "TxEmpty",      NULL),
93         BIT(ISR_IRF,    "RxFull",       NULL),
94         BIT(ISR_GCAD,   "GenCall",      NULL),
95         BIT(ISR_SAD,    "SlaveAddr",    NULL),
96         BIT(ISR_BED,    "BusErr",       NULL),
97 };
98
99 static void decode_ISR(unsigned int val)
100 {
101         decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
102         printk("\n");
103 }
104
105 static const struct bits icr_bits[] = {
106         BIT(ICR_START,  "START",        NULL),
107         BIT(ICR_STOP,   "STOP",         NULL),
108         BIT(ICR_ACKNAK, "ACKNAK",       NULL),
109         BIT(ICR_TB,     "TB",           NULL),
110         BIT(ICR_MA,     "MA",           NULL),
111         BIT(ICR_SCLE,   "SCLE",         "scle"),
112         BIT(ICR_IUE,    "IUE",          "iue"),
113         BIT(ICR_GCD,    "GCD",          NULL),
114         BIT(ICR_ITEIE,  "ITEIE",        NULL),
115         BIT(ICR_IRFIE,  "IRFIE",        NULL),
116         BIT(ICR_BEIE,   "BEIE",         NULL),
117         BIT(ICR_SSDIE,  "SSDIE",        NULL),
118         BIT(ICR_ALDIE,  "ALDIE",        NULL),
119         BIT(ICR_SADIE,  "SADIE",        NULL),
120         BIT(ICR_UR,     "UR",           "ur"),
121 };
122
123 static void decode_ICR(unsigned int val)
124 {
125         decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
126         printk("\n");
127 }
128
129 static unsigned int i2c_debug = DEBUG;
130
131 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
132 {
133         dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno, ISR, ICR, IBMR);
134 }
135
136 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __FUNCTION__)
137 #else
138 #define i2c_debug       0
139
140 #define show_state(i2c) do { } while (0)
141 #define decode_ISR(val) do { } while (0)
142 #define decode_ICR(val) do { } while (0)
143 #endif
144
145 #define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
146
147 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
148
149 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
150 {
151         unsigned int i;
152         printk("i2c: error: %s\n", why);
153         printk("i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
154                 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
155         printk("i2c: ICR: %08x ISR: %08x\n"
156                "i2c: log: ", ICR, ISR);
157         for (i = 0; i < i2c->irqlogidx; i++)
158                 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
159         printk("\n");
160 }
161
162 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
163 {
164         return !(ICR & ICR_SCLE);
165 }
166
167 static void i2c_pxa_abort(struct pxa_i2c *i2c)
168 {
169         unsigned long timeout = jiffies + HZ/4;
170
171         if (i2c_pxa_is_slavemode(i2c)) {
172                 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
173                 return;
174         }
175
176         while (time_before(jiffies, timeout) && (IBMR & 0x1) == 0) {
177                 unsigned long icr = ICR;
178
179                 icr &= ~ICR_START;
180                 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
181
182                 ICR = icr;
183
184                 show_state(i2c);
185
186                 msleep(1);
187         }
188
189         ICR &= ~(ICR_MA | ICR_START | ICR_STOP);
190 }
191
192 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
193 {
194         int timeout = DEF_TIMEOUT;
195
196         while (timeout-- && ISR & (ISR_IBB | ISR_UB)) {
197                 if ((ISR & ISR_SAD) != 0)
198                         timeout += 4;
199
200                 msleep(2);
201                 show_state(i2c);
202         }
203
204         if (timeout <= 0)
205                 show_state(i2c);
206
207         return timeout <= 0 ? I2C_RETRY : 0;
208 }
209
210 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
211 {
212         unsigned long timeout = jiffies + HZ*4;
213
214         while (time_before(jiffies, timeout)) {
215                 if (i2c_debug > 1)
216                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
217                                 __func__, (long)jiffies, ISR, ICR, IBMR);
218
219                 if (ISR & ISR_SAD) {
220                         if (i2c_debug > 0)
221                                 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
222                         goto out;
223                 }
224
225                 /* wait for unit and bus being not busy, and we also do a
226                  * quick check of the i2c lines themselves to ensure they've
227                  * gone high...
228                  */
229                 if ((ISR & (ISR_UB | ISR_IBB)) == 0 && IBMR == 3) {
230                         if (i2c_debug > 0)
231                                 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
232                         return 1;
233                 }
234
235                 msleep(1);
236         }
237
238         if (i2c_debug > 0)
239                 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
240  out:
241         return 0;
242 }
243
244 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
245 {
246         if (i2c_debug)
247                 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
248
249         if ((ISR & (ISR_UB | ISR_IBB)) != 0) {
250                 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
251                 if (!i2c_pxa_wait_master(i2c)) {
252                         dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
253                         return I2C_RETRY;
254                 }
255         }
256
257         ICR |= ICR_SCLE;
258         return 0;
259 }
260
261 #ifdef CONFIG_I2C_PXA_SLAVE
262 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
263 {
264         unsigned long timeout = jiffies + HZ*1;
265
266         /* wait for stop */
267
268         show_state(i2c);
269
270         while (time_before(jiffies, timeout)) {
271                 if (i2c_debug > 1)
272                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
273                                 __func__, (long)jiffies, ISR, ICR, IBMR);
274
275                 if ((ISR & (ISR_UB|ISR_IBB|ISR_SAD)) == ISR_SAD ||
276                     (ICR & ICR_SCLE) == 0) {
277                         if (i2c_debug > 1)
278                                 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
279                         return 1;
280                 }
281
282                 msleep(1);
283         }
284
285         if (i2c_debug > 0)
286                 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
287         return 0;
288 }
289
290 /*
291  * clear the hold on the bus, and take of anything else
292  * that has been configured
293  */
294 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
295 {
296         show_state(i2c);
297
298         if (errcode < 0) {
299                 udelay(100);   /* simple delay */
300         } else {
301                 /* we need to wait for the stop condition to end */
302
303                 /* if we where in stop, then clear... */
304                 if (ICR & ICR_STOP) {
305                         udelay(100);
306                         ICR &= ~ICR_STOP;
307                 }
308
309                 if (!i2c_pxa_wait_slave(i2c)) {
310                         dev_err(&i2c->adap.dev, "%s: wait timedout\n",
311                                 __func__);
312                         return;
313                 }
314         }
315
316         ICR &= ~(ICR_STOP|ICR_ACKNAK|ICR_MA);
317         ICR &= ~ICR_SCLE;
318
319         if (i2c_debug) {
320                 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", ICR, ISR);
321                 decode_ICR(ICR);
322         }
323 }
324 #else
325 #define i2c_pxa_set_slave(i2c, err)     do { } while (0)
326 #endif
327
328 static void i2c_pxa_reset(struct pxa_i2c *i2c)
329 {
330         pr_debug("Resetting I2C Controller Unit\n");
331
332         /* abort any transfer currently under way */
333         i2c_pxa_abort(i2c);
334
335         /* reset according to 9.8 */
336         ICR = ICR_UR;
337         ISR = I2C_ISR_INIT;
338         ICR &= ~ICR_UR;
339
340         ISAR = i2c->slave_addr;
341
342         /* set control register values */
343         ICR = I2C_ICR_INIT;
344
345 #ifdef CONFIG_I2C_PXA_SLAVE
346         dev_info(&i2c->adap.dev, "Enabling slave mode\n");
347         ICR |= ICR_SADIE | ICR_ALDIE | ICR_SSDIE;
348 #endif
349
350         i2c_pxa_set_slave(i2c, 0);
351
352         /* enable unit */
353         ICR |= ICR_IUE;
354         udelay(100);
355 }
356
357
358 #ifdef CONFIG_I2C_PXA_SLAVE
359 /*
360  * I2C EEPROM emulation.
361  */
362 static struct i2c_eeprom_emu eeprom = {
363         .size = I2C_EEPROM_EMU_SIZE,
364         .watch = LIST_HEAD_INIT(eeprom.watch),
365 };
366
367 struct i2c_eeprom_emu *i2c_pxa_get_eeprom(void)
368 {
369         return &eeprom;
370 }
371
372 int i2c_eeprom_emu_addwatcher(struct i2c_eeprom_emu *emu, void *data,
373                               unsigned int addr, unsigned int size,
374                               struct i2c_eeprom_emu_watcher *watcher)
375 {
376         struct i2c_eeprom_emu_watch *watch;
377         unsigned long flags;
378
379         if (addr + size > emu->size)
380                 return -EINVAL;
381
382         watch = kmalloc(sizeof(struct i2c_eeprom_emu_watch), GFP_KERNEL);
383         if (watch) {
384                 watch->start = addr;
385                 watch->end = addr + size - 1;
386                 watch->ops = watcher;
387                 watch->data = data;
388
389                 local_irq_save(flags);
390                 list_add(&watch->node, &emu->watch);
391                 local_irq_restore(flags);
392         }
393
394         return watch ? 0 : -ENOMEM;
395 }
396
397 void i2c_eeprom_emu_delwatcher(struct i2c_eeprom_emu *emu, void *data,
398                                struct i2c_eeprom_emu_watcher *watcher)
399 {
400         struct i2c_eeprom_emu_watch *watch, *n;
401         unsigned long flags;
402
403         list_for_each_entry_safe(watch, n, &emu->watch, node) {
404                 if (watch->ops == watcher && watch->data == data) {
405                         local_irq_save(flags);
406                         list_del(&watch->node);
407                         local_irq_restore(flags);
408                         kfree(watch);
409                 }
410         }
411 }
412
413 static void i2c_eeprom_emu_event(void *ptr, i2c_slave_event_t event)
414 {
415         struct i2c_eeprom_emu *emu = ptr;
416
417         eedbg(3, "i2c_eeprom_emu_event: %d\n", event);
418
419         switch (event) {
420         case I2C_SLAVE_EVENT_START_WRITE:
421                 emu->seen_start = 1;
422                 eedbg(2, "i2c_eeprom: write initiated\n");
423                 break;
424
425         case I2C_SLAVE_EVENT_START_READ:
426                 emu->seen_start = 0;
427                 eedbg(2, "i2c_eeprom: read initiated\n");
428                 break;
429
430         case I2C_SLAVE_EVENT_STOP:
431                 emu->seen_start = 0;
432                 eedbg(2, "i2c_eeprom: received stop\n");
433                 break;
434
435         default:
436                 eedbg(0, "i2c_eeprom: unhandled event\n");
437                 break;
438         }
439 }
440
441 static int i2c_eeprom_emu_read(void *ptr)
442 {
443         struct i2c_eeprom_emu *emu = ptr;
444         int ret;
445
446         ret = emu->bytes[emu->ptr];
447         emu->ptr = (emu->ptr + 1) % emu->size;
448
449         return ret;
450 }
451
452 static void i2c_eeprom_emu_write(void *ptr, unsigned int val)
453 {
454         struct i2c_eeprom_emu *emu = ptr;
455         struct i2c_eeprom_emu_watch *watch;
456
457         if (emu->seen_start != 0) {
458                 eedbg(2, "i2c_eeprom_emu_write: setting ptr %02x\n", val);
459                 emu->ptr = val;
460                 emu->seen_start = 0;
461                 return;
462         }
463
464         emu->bytes[emu->ptr] = val;
465
466         eedbg(1, "i2c_eeprom_emu_write: ptr=0x%02x, val=0x%02x\n",
467               emu->ptr, val);
468
469         list_for_each_entry(watch, &emu->watch, node) {
470                 if (!watch->ops || !watch->ops->write)
471                         continue;
472                 if (watch->start <= emu->ptr && watch->end >= emu->ptr)
473                         watch->ops->write(watch->data, emu->ptr, val);
474         }
475
476         emu->ptr = (emu->ptr + 1) % emu->size;
477 }
478
479 struct i2c_slave_client eeprom_client = {
480         .data   = &eeprom,
481         .event  = i2c_eeprom_emu_event,
482         .read   = i2c_eeprom_emu_read,
483         .write  = i2c_eeprom_emu_write
484 };
485
486 /*
487  * PXA I2C Slave mode
488  */
489
490 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
491 {
492         if (isr & ISR_BED) {
493                 /* what should we do here? */
494         } else {
495                 int ret = i2c->slave->read(i2c->slave->data);
496
497                 IDBR = ret;
498                 ICR |= ICR_TB;   /* allow next byte */
499         }
500 }
501
502 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
503 {
504         unsigned int byte = IDBR;
505
506         if (i2c->slave != NULL)
507                 i2c->slave->write(i2c->slave->data, byte);
508
509         ICR |= ICR_TB;
510 }
511
512 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
513 {
514         int timeout;
515
516         if (i2c_debug > 0)
517                 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
518                        (isr & ISR_RWM) ? 'r' : 't');
519
520         if (i2c->slave != NULL)
521                 i2c->slave->event(i2c->slave->data,
522                                  (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
523
524         /*
525          * slave could interrupt in the middle of us generating a
526          * start condition... if this happens, we'd better back off
527          * and stop holding the poor thing up
528          */
529         ICR &= ~(ICR_START|ICR_STOP);
530         ICR |= ICR_TB;
531
532         timeout = 0x10000;
533
534         while (1) {
535                 if ((IBMR & 2) == 2)
536                         break;
537
538                 timeout--;
539
540                 if (timeout <= 0) {
541                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
542                         break;
543                 }
544         }
545
546         ICR &= ~ICR_SCLE;
547 }
548
549 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
550 {
551         if (i2c_debug > 2)
552                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
553
554         if (i2c->slave != NULL)
555                 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
556
557         if (i2c_debug > 2)
558                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
559
560         /*
561          * If we have a master-mode message waiting,
562          * kick it off now that the slave has completed.
563          */
564         if (i2c->msg)
565                 i2c_pxa_master_complete(i2c, I2C_RETRY);
566 }
567 #else
568 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
569 {
570         if (isr & ISR_BED) {
571                 /* what should we do here? */
572         } else {
573                 IDBR = 0;
574                 ICR |= ICR_TB;
575         }
576 }
577
578 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
579 {
580         ICR |= ICR_TB | ICR_ACKNAK;
581 }
582
583 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
584 {
585         int timeout;
586
587         /*
588          * slave could interrupt in the middle of us generating a
589          * start condition... if this happens, we'd better back off
590          * and stop holding the poor thing up
591          */
592         ICR &= ~(ICR_START|ICR_STOP);
593         ICR |= ICR_TB | ICR_ACKNAK;
594
595         timeout = 0x10000;
596
597         while (1) {
598                 if ((IBMR & 2) == 2)
599                         break;
600
601                 timeout--;
602
603                 if (timeout <= 0) {
604                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
605                         break;
606                 }
607         }
608
609         ICR &= ~ICR_SCLE;
610 }
611
612 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
613 {
614         if (i2c->msg)
615                 i2c_pxa_master_complete(i2c, I2C_RETRY);
616 }
617 #endif
618
619 /*
620  * PXA I2C Master mode
621  */
622
623 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
624 {
625         unsigned int addr = (msg->addr & 0x7f) << 1;
626
627         if (msg->flags & I2C_M_RD)
628                 addr |= 1;
629
630         return addr;
631 }
632
633 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
634 {
635         u32 icr;
636
637         /*
638          * Step 1: target slave address into IDBR
639          */
640         IDBR = i2c_pxa_addr_byte(i2c->msg);
641
642         /*
643          * Step 2: initiate the write.
644          */
645         icr = ICR & ~(ICR_STOP | ICR_ALDIE);
646         ICR = icr | ICR_START | ICR_TB;
647 }
648
649 /*
650  * We are protected by the adapter bus semaphore.
651  */
652 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
653 {
654         long timeout;
655         int ret;
656
657         /*
658          * Wait for the bus to become free.
659          */
660         ret = i2c_pxa_wait_bus_not_busy(i2c);
661         if (ret) {
662                 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
663                 goto out;
664         }
665
666         /*
667          * Set master mode.
668          */
669         ret = i2c_pxa_set_master(i2c);
670         if (ret) {
671                 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
672                 goto out;
673         }
674
675         spin_lock_irq(&i2c->lock);
676
677         i2c->msg = msg;
678         i2c->msg_num = num;
679         i2c->msg_idx = 0;
680         i2c->msg_ptr = 0;
681         i2c->irqlogidx = 0;
682
683         i2c_pxa_start_message(i2c);
684
685         spin_unlock_irq(&i2c->lock);
686
687         /*
688          * The rest of the processing occurs in the interrupt handler.
689          */
690         timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
691
692         /*
693          * We place the return code in i2c->msg_idx.
694          */
695         ret = i2c->msg_idx;
696
697         if (timeout == 0)
698                 i2c_pxa_scream_blue_murder(i2c, "timeout");
699
700  out:
701         return ret;
702 }
703
704 /*
705  * i2c_pxa_master_complete - complete the message and wake up.
706  */
707 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
708 {
709         i2c->msg_ptr = 0;
710         i2c->msg = NULL;
711         i2c->msg_idx ++;
712         i2c->msg_num = 0;
713         if (ret)
714                 i2c->msg_idx = ret;
715         wake_up(&i2c->wait);
716 }
717
718 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
719 {
720         u32 icr = ICR & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
721
722  again:
723         /*
724          * If ISR_ALD is set, we lost arbitration.
725          */
726         if (isr & ISR_ALD) {
727                 /*
728                  * Do we need to do anything here?  The PXA docs
729                  * are vague about what happens.
730                  */
731                 i2c_pxa_scream_blue_murder(i2c, "ALD set");
732
733                 /*
734                  * We ignore this error.  We seem to see spurious ALDs
735                  * for seemingly no reason.  If we handle them as I think
736                  * they should, we end up causing an I2C error, which
737                  * is painful for some systems.
738                  */
739                 return; /* ignore */
740         }
741
742         if (isr & ISR_BED) {
743                 int ret = BUS_ERROR;
744
745                 /*
746                  * I2C bus error - either the device NAK'd us, or
747                  * something more serious happened.  If we were NAK'd
748                  * on the initial address phase, we can retry.
749                  */
750                 if (isr & ISR_ACKNAK) {
751                         if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
752                                 ret = I2C_RETRY;
753                         else
754                                 ret = XFER_NAKED;
755                 }
756                 i2c_pxa_master_complete(i2c, ret);
757         } else if (isr & ISR_RWM) {
758                 /*
759                  * Read mode.  We have just sent the address byte, and
760                  * now we must initiate the transfer.
761                  */
762                 if (i2c->msg_ptr == i2c->msg->len - 1 &&
763                     i2c->msg_idx == i2c->msg_num - 1)
764                         icr |= ICR_STOP | ICR_ACKNAK;
765
766                 icr |= ICR_ALDIE | ICR_TB;
767         } else if (i2c->msg_ptr < i2c->msg->len) {
768                 /*
769                  * Write mode.  Write the next data byte.
770                  */
771                 IDBR = i2c->msg->buf[i2c->msg_ptr++];
772
773                 icr |= ICR_ALDIE | ICR_TB;
774
775                 /*
776                  * If this is the last byte of the last message, send
777                  * a STOP.
778                  */
779                 if (i2c->msg_ptr == i2c->msg->len &&
780                     i2c->msg_idx == i2c->msg_num - 1)
781                         icr |= ICR_STOP;
782         } else if (i2c->msg_idx < i2c->msg_num - 1) {
783                 /*
784                  * Next segment of the message.
785                  */
786                 i2c->msg_ptr = 0;
787                 i2c->msg_idx ++;
788                 i2c->msg++;
789
790                 /*
791                  * If we aren't doing a repeated start and address,
792                  * go back and try to send the next byte.  Note that
793                  * we do not support switching the R/W direction here.
794                  */
795                 if (i2c->msg->flags & I2C_M_NOSTART)
796                         goto again;
797
798                 /*
799                  * Write the next address.
800                  */
801                 IDBR = i2c_pxa_addr_byte(i2c->msg);
802
803                 /*
804                  * And trigger a repeated start, and send the byte.
805                  */
806                 icr &= ~ICR_ALDIE;
807                 icr |= ICR_START | ICR_TB;
808         } else {
809                 if (i2c->msg->len == 0) {
810                         /*
811                          * Device probes have a message length of zero
812                          * and need the bus to be reset before it can
813                          * be used again.
814                          */
815                         i2c_pxa_reset(i2c);
816                 }
817                 i2c_pxa_master_complete(i2c, 0);
818         }
819
820         i2c->icrlog[i2c->irqlogidx-1] = icr;
821
822         ICR = icr;
823         show_state(i2c);
824 }
825
826 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
827 {
828         u32 icr = ICR & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
829
830         /*
831          * Read the byte.
832          */
833         i2c->msg->buf[i2c->msg_ptr++] = IDBR;
834
835         if (i2c->msg_ptr < i2c->msg->len) {
836                 /*
837                  * If this is the last byte of the last
838                  * message, send a STOP.
839                  */
840                 if (i2c->msg_ptr == i2c->msg->len - 1)
841                         icr |= ICR_STOP | ICR_ACKNAK;
842
843                 icr |= ICR_ALDIE | ICR_TB;
844         } else {
845                 i2c_pxa_master_complete(i2c, 0);
846         }
847
848         i2c->icrlog[i2c->irqlogidx-1] = icr;
849
850         ICR = icr;
851 }
852
853 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id, struct pt_regs *regs)
854 {
855         struct pxa_i2c *i2c = dev_id;
856         u32 isr = ISR;
857
858         if (i2c_debug > 2 && 0) {
859                 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
860                         __func__, isr, ICR, IBMR);
861                 decode_ISR(isr);
862         }
863
864         if (i2c->irqlogidx < sizeof(i2c->isrlog)/sizeof(u32))
865                 i2c->isrlog[i2c->irqlogidx++] = isr;
866
867         show_state(i2c);
868
869         /*
870          * Always clear all pending IRQs.
871          */
872         ISR = isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED);
873
874         if (isr & ISR_SAD)
875                 i2c_pxa_slave_start(i2c, isr);
876         if (isr & ISR_SSD)
877                 i2c_pxa_slave_stop(i2c);
878
879         if (i2c_pxa_is_slavemode(i2c)) {
880                 if (isr & ISR_ITE)
881                         i2c_pxa_slave_txempty(i2c, isr);
882                 if (isr & ISR_IRF)
883                         i2c_pxa_slave_rxfull(i2c, isr);
884         } else if (i2c->msg) {
885                 if (isr & ISR_ITE)
886                         i2c_pxa_irq_txempty(i2c, isr);
887                 if (isr & ISR_IRF)
888                         i2c_pxa_irq_rxfull(i2c, isr);
889         } else {
890                 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
891         }
892
893         return IRQ_HANDLED;
894 }
895
896
897 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
898 {
899         struct pxa_i2c *i2c = adap->algo_data;
900         int ret, i;
901
902         for (i = adap->retries; i >= 0; i--) {
903                 ret = i2c_pxa_do_xfer(i2c, msgs, num);
904                 if (ret != I2C_RETRY)
905                         goto out;
906
907                 if (i2c_debug)
908                         dev_dbg(&adap->dev, "Retrying transmission\n");
909                 udelay(100);
910         }
911         i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
912         ret = -EREMOTEIO;
913  out:
914         i2c_pxa_set_slave(i2c, ret);
915         return ret;
916 }
917
918 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
919 {
920         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
921 }
922
923 static struct i2c_algorithm i2c_pxa_algorithm = {
924         .master_xfer    = i2c_pxa_xfer,
925         .functionality  = i2c_pxa_functionality,
926 };
927
928 static struct pxa_i2c i2c_pxa = {
929         .lock   = SPIN_LOCK_UNLOCKED,
930         .wait   = __WAIT_QUEUE_HEAD_INITIALIZER(i2c_pxa.wait),
931         .adap   = {
932                 .owner          = THIS_MODULE,
933                 .algo           = &i2c_pxa_algorithm,
934                 .name           = "pxa2xx-i2c",
935                 .retries        = 5,
936         },
937 };
938
939 static int i2c_pxa_probe(struct device *dev)
940 {
941         struct pxa_i2c *i2c = &i2c_pxa;
942         struct i2c_pxa_platform_data *plat = dev->platform_data;
943         int ret;
944
945 #ifdef CONFIG_PXA27x
946         pxa_gpio_mode(GPIO117_I2CSCL_MD);
947         pxa_gpio_mode(GPIO118_I2CSDA_MD);
948         udelay(100);
949 #endif
950
951         i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
952
953 #ifdef CONFIG_I2C_PXA_SLAVE
954         i2c->slave = &eeprom_client;
955         if (plat) {
956                 i2c->slave_addr = plat->slave_addr;
957                 if (plat->slave)
958                         i2c->slave = plat->slave;
959         }
960 #endif
961
962         pxa_set_cken(CKEN14_I2C, 1);
963         ret = request_irq(IRQ_I2C, i2c_pxa_handler, SA_INTERRUPT,
964                           "pxa2xx-i2c", i2c);
965         if (ret)
966                 goto out;
967
968         i2c_pxa_reset(i2c);
969
970         i2c->adap.algo_data = i2c;
971         i2c->adap.dev.parent = dev;
972
973         ret = i2c_add_adapter(&i2c->adap);
974         if (ret < 0) {
975                 printk(KERN_INFO "I2C: Failed to add bus\n");
976                 goto err_irq;
977         }
978
979         dev_set_drvdata(dev, i2c);
980
981 #ifdef CONFIG_I2C_PXA_SLAVE
982         printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
983                i2c->adap.dev.bus_id, i2c->slave_addr);
984 #else
985         printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
986                i2c->adap.dev.bus_id);
987 #endif
988         return 0;
989
990  err_irq:
991         free_irq(IRQ_I2C, i2c);
992  out:
993         return ret;
994 }
995
996 static int i2c_pxa_remove(struct device *dev)
997 {
998         struct pxa_i2c *i2c = dev_get_drvdata(dev);
999
1000         dev_set_drvdata(dev, NULL);
1001
1002         i2c_del_adapter(&i2c->adap);
1003         free_irq(IRQ_I2C, i2c);
1004         pxa_set_cken(CKEN14_I2C, 0);
1005
1006         return 0;
1007 }
1008
1009 static struct device_driver i2c_pxa_driver = {
1010         .name           = "pxa2xx-i2c",
1011         .bus            = &platform_bus_type,
1012         .probe          = i2c_pxa_probe,
1013         .remove         = i2c_pxa_remove,
1014 };
1015
1016 static int __init i2c_adap_pxa_init(void)
1017 {
1018         return driver_register(&i2c_pxa_driver);
1019 }
1020
1021 static void i2c_adap_pxa_exit(void)
1022 {
1023         return driver_unregister(&i2c_pxa_driver);
1024 }
1025
1026 module_init(i2c_adap_pxa_init);
1027 module_exit(i2c_adap_pxa_exit);