Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
[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 #include <linux/err.h>
35 #include <linux/clk.h>
36
37 #include <mach/hardware.h>
38 #include <asm/irq.h>
39 #include <asm/io.h>
40 #include <mach/i2c.h>
41
42 /*
43  * I2C registers and bit definitions
44  */
45 #define IBMR            (0x00)
46 #define IDBR            (0x08)
47 #define ICR             (0x10)
48 #define ISR             (0x18)
49 #define ISAR            (0x20)
50
51 #define ICR_START       (1 << 0)           /* start bit */
52 #define ICR_STOP        (1 << 1)           /* stop bit */
53 #define ICR_ACKNAK      (1 << 2)           /* send ACK(0) or NAK(1) */
54 #define ICR_TB          (1 << 3)           /* transfer byte bit */
55 #define ICR_MA          (1 << 4)           /* master abort */
56 #define ICR_SCLE        (1 << 5)           /* master clock enable */
57 #define ICR_IUE         (1 << 6)           /* unit enable */
58 #define ICR_GCD         (1 << 7)           /* general call disable */
59 #define ICR_ITEIE       (1 << 8)           /* enable tx interrupts */
60 #define ICR_IRFIE       (1 << 9)           /* enable rx interrupts */
61 #define ICR_BEIE        (1 << 10)          /* enable bus error ints */
62 #define ICR_SSDIE       (1 << 11)          /* slave STOP detected int enable */
63 #define ICR_ALDIE       (1 << 12)          /* enable arbitration interrupt */
64 #define ICR_SADIE       (1 << 13)          /* slave address detected int enable */
65 #define ICR_UR          (1 << 14)          /* unit reset */
66 #define ICR_FM          (1 << 15)          /* fast mode */
67
68 #define ISR_RWM         (1 << 0)           /* read/write mode */
69 #define ISR_ACKNAK      (1 << 1)           /* ack/nak status */
70 #define ISR_UB          (1 << 2)           /* unit busy */
71 #define ISR_IBB         (1 << 3)           /* bus busy */
72 #define ISR_SSD         (1 << 4)           /* slave stop detected */
73 #define ISR_ALD         (1 << 5)           /* arbitration loss detected */
74 #define ISR_ITE         (1 << 6)           /* tx buffer empty */
75 #define ISR_IRF         (1 << 7)           /* rx buffer full */
76 #define ISR_GCAD        (1 << 8)           /* general call address detected */
77 #define ISR_SAD         (1 << 9)           /* slave address detected */
78 #define ISR_BED         (1 << 10)          /* bus error no ACK/NAK */
79
80 struct pxa_i2c {
81         spinlock_t              lock;
82         wait_queue_head_t       wait;
83         struct i2c_msg          *msg;
84         unsigned int            msg_num;
85         unsigned int            msg_idx;
86         unsigned int            msg_ptr;
87         unsigned int            slave_addr;
88
89         struct i2c_adapter      adap;
90         struct clk              *clk;
91 #ifdef CONFIG_I2C_PXA_SLAVE
92         struct i2c_slave_client *slave;
93 #endif
94
95         unsigned int            irqlogidx;
96         u32                     isrlog[32];
97         u32                     icrlog[32];
98
99         void __iomem            *reg_base;
100         unsigned int            reg_shift;
101
102         unsigned long           iobase;
103         unsigned long           iosize;
104
105         int                     irq;
106         unsigned int            use_pio :1;
107         unsigned int            fast_mode :1;
108 };
109
110 #define _IBMR(i2c)      ((i2c)->reg_base + (0x0 << (i2c)->reg_shift))
111 #define _IDBR(i2c)      ((i2c)->reg_base + (0x4 << (i2c)->reg_shift))
112 #define _ICR(i2c)       ((i2c)->reg_base + (0x8 << (i2c)->reg_shift))
113 #define _ISR(i2c)       ((i2c)->reg_base + (0xc << (i2c)->reg_shift))
114 #define _ISAR(i2c)      ((i2c)->reg_base + (0x10 << (i2c)->reg_shift))
115
116 /*
117  * I2C Slave mode address
118  */
119 #define I2C_PXA_SLAVE_ADDR      0x1
120
121 #ifdef DEBUG
122
123 struct bits {
124         u32     mask;
125         const char *set;
126         const char *unset;
127 };
128 #define PXA_BIT(m, s, u)        { .mask = m, .set = s, .unset = u }
129
130 static inline void
131 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
132 {
133         printk("%s %08x: ", prefix, val);
134         while (num--) {
135                 const char *str = val & bits->mask ? bits->set : bits->unset;
136                 if (str)
137                         printk("%s ", str);
138                 bits++;
139         }
140 }
141
142 static const struct bits isr_bits[] = {
143         PXA_BIT(ISR_RWM,        "RX",           "TX"),
144         PXA_BIT(ISR_ACKNAK,     "NAK",          "ACK"),
145         PXA_BIT(ISR_UB,         "Bsy",          "Rdy"),
146         PXA_BIT(ISR_IBB,        "BusBsy",       "BusRdy"),
147         PXA_BIT(ISR_SSD,        "SlaveStop",    NULL),
148         PXA_BIT(ISR_ALD,        "ALD",          NULL),
149         PXA_BIT(ISR_ITE,        "TxEmpty",      NULL),
150         PXA_BIT(ISR_IRF,        "RxFull",       NULL),
151         PXA_BIT(ISR_GCAD,       "GenCall",      NULL),
152         PXA_BIT(ISR_SAD,        "SlaveAddr",    NULL),
153         PXA_BIT(ISR_BED,        "BusErr",       NULL),
154 };
155
156 static void decode_ISR(unsigned int val)
157 {
158         decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
159         printk("\n");
160 }
161
162 static const struct bits icr_bits[] = {
163         PXA_BIT(ICR_START,  "START",    NULL),
164         PXA_BIT(ICR_STOP,   "STOP",     NULL),
165         PXA_BIT(ICR_ACKNAK, "ACKNAK",   NULL),
166         PXA_BIT(ICR_TB,     "TB",       NULL),
167         PXA_BIT(ICR_MA,     "MA",       NULL),
168         PXA_BIT(ICR_SCLE,   "SCLE",     "scle"),
169         PXA_BIT(ICR_IUE,    "IUE",      "iue"),
170         PXA_BIT(ICR_GCD,    "GCD",      NULL),
171         PXA_BIT(ICR_ITEIE,  "ITEIE",    NULL),
172         PXA_BIT(ICR_IRFIE,  "IRFIE",    NULL),
173         PXA_BIT(ICR_BEIE,   "BEIE",     NULL),
174         PXA_BIT(ICR_SSDIE,  "SSDIE",    NULL),
175         PXA_BIT(ICR_ALDIE,  "ALDIE",    NULL),
176         PXA_BIT(ICR_SADIE,  "SADIE",    NULL),
177         PXA_BIT(ICR_UR,     "UR",               "ur"),
178 };
179
180 #ifdef CONFIG_I2C_PXA_SLAVE
181 static void decode_ICR(unsigned int val)
182 {
183         decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
184         printk("\n");
185 }
186 #endif
187
188 static unsigned int i2c_debug = DEBUG;
189
190 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
191 {
192         dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
193                 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
194 }
195
196 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
197 #else
198 #define i2c_debug       0
199
200 #define show_state(i2c) do { } while (0)
201 #define decode_ISR(val) do { } while (0)
202 #define decode_ICR(val) do { } while (0)
203 #endif
204
205 #define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
206
207 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
208 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
209
210 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
211 {
212         unsigned int i;
213         printk(KERN_ERR "i2c: error: %s\n", why);
214         printk(KERN_ERR "i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
215                 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
216         printk(KERN_ERR "i2c: ICR: %08x ISR: %08x\n",
217                readl(_ICR(i2c)), readl(_ISR(i2c)));
218         printk(KERN_DEBUG "i2c: log: ");
219         for (i = 0; i < i2c->irqlogidx; i++)
220                 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
221         printk("\n");
222 }
223
224 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
225 {
226         return !(readl(_ICR(i2c)) & ICR_SCLE);
227 }
228
229 static void i2c_pxa_abort(struct pxa_i2c *i2c)
230 {
231         int i = 250;
232
233         if (i2c_pxa_is_slavemode(i2c)) {
234                 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
235                 return;
236         }
237
238         while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
239                 unsigned long icr = readl(_ICR(i2c));
240
241                 icr &= ~ICR_START;
242                 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
243
244                 writel(icr, _ICR(i2c));
245
246                 show_state(i2c);
247
248                 mdelay(1);
249                 i --;
250         }
251
252         writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
253                _ICR(i2c));
254 }
255
256 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
257 {
258         int timeout = DEF_TIMEOUT;
259
260         while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
261                 if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
262                         timeout += 4;
263
264                 msleep(2);
265                 show_state(i2c);
266         }
267
268         if (timeout <= 0)
269                 show_state(i2c);
270
271         return timeout <= 0 ? I2C_RETRY : 0;
272 }
273
274 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
275 {
276         unsigned long timeout = jiffies + HZ*4;
277
278         while (time_before(jiffies, timeout)) {
279                 if (i2c_debug > 1)
280                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
281                                 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
282
283                 if (readl(_ISR(i2c)) & ISR_SAD) {
284                         if (i2c_debug > 0)
285                                 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
286                         goto out;
287                 }
288
289                 /* wait for unit and bus being not busy, and we also do a
290                  * quick check of the i2c lines themselves to ensure they've
291                  * gone high...
292                  */
293                 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
294                         if (i2c_debug > 0)
295                                 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
296                         return 1;
297                 }
298
299                 msleep(1);
300         }
301
302         if (i2c_debug > 0)
303                 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
304  out:
305         return 0;
306 }
307
308 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
309 {
310         if (i2c_debug)
311                 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
312
313         if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
314                 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
315                 if (!i2c_pxa_wait_master(i2c)) {
316                         dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
317                         return I2C_RETRY;
318                 }
319         }
320
321         writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
322         return 0;
323 }
324
325 #ifdef CONFIG_I2C_PXA_SLAVE
326 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
327 {
328         unsigned long timeout = jiffies + HZ*1;
329
330         /* wait for stop */
331
332         show_state(i2c);
333
334         while (time_before(jiffies, timeout)) {
335                 if (i2c_debug > 1)
336                         dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
337                                 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
338
339                 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
340                     (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
341                     (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
342                         if (i2c_debug > 1)
343                                 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
344                         return 1;
345                 }
346
347                 msleep(1);
348         }
349
350         if (i2c_debug > 0)
351                 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
352         return 0;
353 }
354
355 /*
356  * clear the hold on the bus, and take of anything else
357  * that has been configured
358  */
359 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
360 {
361         show_state(i2c);
362
363         if (errcode < 0) {
364                 udelay(100);   /* simple delay */
365         } else {
366                 /* we need to wait for the stop condition to end */
367
368                 /* if we where in stop, then clear... */
369                 if (readl(_ICR(i2c)) & ICR_STOP) {
370                         udelay(100);
371                         writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
372                 }
373
374                 if (!i2c_pxa_wait_slave(i2c)) {
375                         dev_err(&i2c->adap.dev, "%s: wait timedout\n",
376                                 __func__);
377                         return;
378                 }
379         }
380
381         writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
382         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
383
384         if (i2c_debug) {
385                 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
386                 decode_ICR(readl(_ICR(i2c)));
387         }
388 }
389 #else
390 #define i2c_pxa_set_slave(i2c, err)     do { } while (0)
391 #endif
392
393 static void i2c_pxa_reset(struct pxa_i2c *i2c)
394 {
395         pr_debug("Resetting I2C Controller Unit\n");
396
397         /* abort any transfer currently under way */
398         i2c_pxa_abort(i2c);
399
400         /* reset according to 9.8 */
401         writel(ICR_UR, _ICR(i2c));
402         writel(I2C_ISR_INIT, _ISR(i2c));
403         writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
404
405         writel(i2c->slave_addr, _ISAR(i2c));
406
407         /* set control register values */
408         writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
409
410 #ifdef CONFIG_I2C_PXA_SLAVE
411         dev_info(&i2c->adap.dev, "Enabling slave mode\n");
412         writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
413 #endif
414
415         i2c_pxa_set_slave(i2c, 0);
416
417         /* enable unit */
418         writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
419         udelay(100);
420 }
421
422
423 #ifdef CONFIG_I2C_PXA_SLAVE
424 /*
425  * PXA I2C Slave mode
426  */
427
428 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
429 {
430         if (isr & ISR_BED) {
431                 /* what should we do here? */
432         } else {
433                 int ret = 0;
434
435                 if (i2c->slave != NULL)
436                         ret = i2c->slave->read(i2c->slave->data);
437
438                 writel(ret, _IDBR(i2c));
439                 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));   /* allow next byte */
440         }
441 }
442
443 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
444 {
445         unsigned int byte = readl(_IDBR(i2c));
446
447         if (i2c->slave != NULL)
448                 i2c->slave->write(i2c->slave->data, byte);
449
450         writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
451 }
452
453 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
454 {
455         int timeout;
456
457         if (i2c_debug > 0)
458                 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
459                        (isr & ISR_RWM) ? 'r' : 't');
460
461         if (i2c->slave != NULL)
462                 i2c->slave->event(i2c->slave->data,
463                                  (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
464
465         /*
466          * slave could interrupt in the middle of us generating a
467          * start condition... if this happens, we'd better back off
468          * and stop holding the poor thing up
469          */
470         writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
471         writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
472
473         timeout = 0x10000;
474
475         while (1) {
476                 if ((readl(_IBMR(i2c)) & 2) == 2)
477                         break;
478
479                 timeout--;
480
481                 if (timeout <= 0) {
482                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
483                         break;
484                 }
485         }
486
487         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
488 }
489
490 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
491 {
492         if (i2c_debug > 2)
493                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
494
495         if (i2c->slave != NULL)
496                 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
497
498         if (i2c_debug > 2)
499                 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
500
501         /*
502          * If we have a master-mode message waiting,
503          * kick it off now that the slave has completed.
504          */
505         if (i2c->msg)
506                 i2c_pxa_master_complete(i2c, I2C_RETRY);
507 }
508 #else
509 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
510 {
511         if (isr & ISR_BED) {
512                 /* what should we do here? */
513         } else {
514                 writel(0, _IDBR(i2c));
515                 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
516         }
517 }
518
519 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
520 {
521         writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
522 }
523
524 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
525 {
526         int timeout;
527
528         /*
529          * slave could interrupt in the middle of us generating a
530          * start condition... if this happens, we'd better back off
531          * and stop holding the poor thing up
532          */
533         writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
534         writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
535
536         timeout = 0x10000;
537
538         while (1) {
539                 if ((readl(_IBMR(i2c)) & 2) == 2)
540                         break;
541
542                 timeout--;
543
544                 if (timeout <= 0) {
545                         dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
546                         break;
547                 }
548         }
549
550         writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
551 }
552
553 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
554 {
555         if (i2c->msg)
556                 i2c_pxa_master_complete(i2c, I2C_RETRY);
557 }
558 #endif
559
560 /*
561  * PXA I2C Master mode
562  */
563
564 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
565 {
566         unsigned int addr = (msg->addr & 0x7f) << 1;
567
568         if (msg->flags & I2C_M_RD)
569                 addr |= 1;
570
571         return addr;
572 }
573
574 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
575 {
576         u32 icr;
577
578         /*
579          * Step 1: target slave address into IDBR
580          */
581         writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
582
583         /*
584          * Step 2: initiate the write.
585          */
586         icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
587         writel(icr | ICR_START | ICR_TB, _ICR(i2c));
588 }
589
590 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
591 {
592         u32 icr;
593
594         /*
595          * Clear the STOP and ACK flags
596          */
597         icr = readl(_ICR(i2c));
598         icr &= ~(ICR_STOP | ICR_ACKNAK);
599         writel(icr, _ICR(i2c));
600 }
601
602 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
603 {
604         /* make timeout the same as for interrupt based functions */
605         long timeout = 2 * DEF_TIMEOUT;
606
607         /*
608          * Wait for the bus to become free.
609          */
610         while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
611                 udelay(1000);
612                 show_state(i2c);
613         }
614
615         if (timeout <= 0) {
616                 show_state(i2c);
617                 dev_err(&i2c->adap.dev,
618                         "i2c_pxa: timeout waiting for bus free\n");
619                 return I2C_RETRY;
620         }
621
622         /*
623          * Set master mode.
624          */
625         writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
626
627         return 0;
628 }
629
630 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
631                                struct i2c_msg *msg, int num)
632 {
633         unsigned long timeout = 500000; /* 5 seconds */
634         int ret = 0;
635
636         ret = i2c_pxa_pio_set_master(i2c);
637         if (ret)
638                 goto out;
639
640         i2c->msg = msg;
641         i2c->msg_num = num;
642         i2c->msg_idx = 0;
643         i2c->msg_ptr = 0;
644         i2c->irqlogidx = 0;
645
646         i2c_pxa_start_message(i2c);
647
648         while (i2c->msg_num > 0 && --timeout) {
649                 i2c_pxa_handler(0, i2c);
650                 udelay(10);
651         }
652
653         i2c_pxa_stop_message(i2c);
654
655         /*
656          * We place the return code in i2c->msg_idx.
657          */
658         ret = i2c->msg_idx;
659
660 out:
661         if (timeout == 0)
662                 i2c_pxa_scream_blue_murder(i2c, "timeout");
663
664         return ret;
665 }
666
667 /*
668  * We are protected by the adapter bus mutex.
669  */
670 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
671 {
672         long timeout;
673         int ret;
674
675         /*
676          * Wait for the bus to become free.
677          */
678         ret = i2c_pxa_wait_bus_not_busy(i2c);
679         if (ret) {
680                 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
681                 goto out;
682         }
683
684         /*
685          * Set master mode.
686          */
687         ret = i2c_pxa_set_master(i2c);
688         if (ret) {
689                 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
690                 goto out;
691         }
692
693         spin_lock_irq(&i2c->lock);
694
695         i2c->msg = msg;
696         i2c->msg_num = num;
697         i2c->msg_idx = 0;
698         i2c->msg_ptr = 0;
699         i2c->irqlogidx = 0;
700
701         i2c_pxa_start_message(i2c);
702
703         spin_unlock_irq(&i2c->lock);
704
705         /*
706          * The rest of the processing occurs in the interrupt handler.
707          */
708         timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
709         i2c_pxa_stop_message(i2c);
710
711         /*
712          * We place the return code in i2c->msg_idx.
713          */
714         ret = i2c->msg_idx;
715
716         if (timeout == 0)
717                 i2c_pxa_scream_blue_murder(i2c, "timeout");
718
719  out:
720         return ret;
721 }
722
723 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
724                             struct i2c_msg msgs[], int num)
725 {
726         struct pxa_i2c *i2c = adap->algo_data;
727         int ret, i;
728
729         /* If the I2C controller is disabled we need to reset it
730           (probably due to a suspend/resume destroying state). We do
731           this here as we can then avoid worrying about resuming the
732           controller before its users. */
733         if (!(readl(_ICR(i2c)) & ICR_IUE))
734                 i2c_pxa_reset(i2c);
735
736         for (i = adap->retries; i >= 0; i--) {
737                 ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
738                 if (ret != I2C_RETRY)
739                         goto out;
740
741                 if (i2c_debug)
742                         dev_dbg(&adap->dev, "Retrying transmission\n");
743                 udelay(100);
744         }
745         i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
746         ret = -EREMOTEIO;
747  out:
748         i2c_pxa_set_slave(i2c, ret);
749         return ret;
750 }
751
752 /*
753  * i2c_pxa_master_complete - complete the message and wake up.
754  */
755 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
756 {
757         i2c->msg_ptr = 0;
758         i2c->msg = NULL;
759         i2c->msg_idx ++;
760         i2c->msg_num = 0;
761         if (ret)
762                 i2c->msg_idx = ret;
763         if (!i2c->use_pio)
764                 wake_up(&i2c->wait);
765 }
766
767 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
768 {
769         u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
770
771  again:
772         /*
773          * If ISR_ALD is set, we lost arbitration.
774          */
775         if (isr & ISR_ALD) {
776                 /*
777                  * Do we need to do anything here?  The PXA docs
778                  * are vague about what happens.
779                  */
780                 i2c_pxa_scream_blue_murder(i2c, "ALD set");
781
782                 /*
783                  * We ignore this error.  We seem to see spurious ALDs
784                  * for seemingly no reason.  If we handle them as I think
785                  * they should, we end up causing an I2C error, which
786                  * is painful for some systems.
787                  */
788                 return; /* ignore */
789         }
790
791         if (isr & ISR_BED) {
792                 int ret = BUS_ERROR;
793
794                 /*
795                  * I2C bus error - either the device NAK'd us, or
796                  * something more serious happened.  If we were NAK'd
797                  * on the initial address phase, we can retry.
798                  */
799                 if (isr & ISR_ACKNAK) {
800                         if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
801                                 ret = I2C_RETRY;
802                         else
803                                 ret = XFER_NAKED;
804                 }
805                 i2c_pxa_master_complete(i2c, ret);
806         } else if (isr & ISR_RWM) {
807                 /*
808                  * Read mode.  We have just sent the address byte, and
809                  * now we must initiate the transfer.
810                  */
811                 if (i2c->msg_ptr == i2c->msg->len - 1 &&
812                     i2c->msg_idx == i2c->msg_num - 1)
813                         icr |= ICR_STOP | ICR_ACKNAK;
814
815                 icr |= ICR_ALDIE | ICR_TB;
816         } else if (i2c->msg_ptr < i2c->msg->len) {
817                 /*
818                  * Write mode.  Write the next data byte.
819                  */
820                 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
821
822                 icr |= ICR_ALDIE | ICR_TB;
823
824                 /*
825                  * If this is the last byte of the last message, send
826                  * a STOP.
827                  */
828                 if (i2c->msg_ptr == i2c->msg->len &&
829                     i2c->msg_idx == i2c->msg_num - 1)
830                         icr |= ICR_STOP;
831         } else if (i2c->msg_idx < i2c->msg_num - 1) {
832                 /*
833                  * Next segment of the message.
834                  */
835                 i2c->msg_ptr = 0;
836                 i2c->msg_idx ++;
837                 i2c->msg++;
838
839                 /*
840                  * If we aren't doing a repeated start and address,
841                  * go back and try to send the next byte.  Note that
842                  * we do not support switching the R/W direction here.
843                  */
844                 if (i2c->msg->flags & I2C_M_NOSTART)
845                         goto again;
846
847                 /*
848                  * Write the next address.
849                  */
850                 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
851
852                 /*
853                  * And trigger a repeated start, and send the byte.
854                  */
855                 icr &= ~ICR_ALDIE;
856                 icr |= ICR_START | ICR_TB;
857         } else {
858                 if (i2c->msg->len == 0) {
859                         /*
860                          * Device probes have a message length of zero
861                          * and need the bus to be reset before it can
862                          * be used again.
863                          */
864                         i2c_pxa_reset(i2c);
865                 }
866                 i2c_pxa_master_complete(i2c, 0);
867         }
868
869         i2c->icrlog[i2c->irqlogidx-1] = icr;
870
871         writel(icr, _ICR(i2c));
872         show_state(i2c);
873 }
874
875 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
876 {
877         u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
878
879         /*
880          * Read the byte.
881          */
882         i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
883
884         if (i2c->msg_ptr < i2c->msg->len) {
885                 /*
886                  * If this is the last byte of the last
887                  * message, send a STOP.
888                  */
889                 if (i2c->msg_ptr == i2c->msg->len - 1)
890                         icr |= ICR_STOP | ICR_ACKNAK;
891
892                 icr |= ICR_ALDIE | ICR_TB;
893         } else {
894                 i2c_pxa_master_complete(i2c, 0);
895         }
896
897         i2c->icrlog[i2c->irqlogidx-1] = icr;
898
899         writel(icr, _ICR(i2c));
900 }
901
902 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
903 {
904         struct pxa_i2c *i2c = dev_id;
905         u32 isr = readl(_ISR(i2c));
906
907         if (i2c_debug > 2 && 0) {
908                 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
909                         __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
910                 decode_ISR(isr);
911         }
912
913         if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
914                 i2c->isrlog[i2c->irqlogidx++] = isr;
915
916         show_state(i2c);
917
918         /*
919          * Always clear all pending IRQs.
920          */
921         writel(isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED), _ISR(i2c));
922
923         if (isr & ISR_SAD)
924                 i2c_pxa_slave_start(i2c, isr);
925         if (isr & ISR_SSD)
926                 i2c_pxa_slave_stop(i2c);
927
928         if (i2c_pxa_is_slavemode(i2c)) {
929                 if (isr & ISR_ITE)
930                         i2c_pxa_slave_txempty(i2c, isr);
931                 if (isr & ISR_IRF)
932                         i2c_pxa_slave_rxfull(i2c, isr);
933         } else if (i2c->msg) {
934                 if (isr & ISR_ITE)
935                         i2c_pxa_irq_txempty(i2c, isr);
936                 if (isr & ISR_IRF)
937                         i2c_pxa_irq_rxfull(i2c, isr);
938         } else {
939                 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
940         }
941
942         return IRQ_HANDLED;
943 }
944
945
946 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
947 {
948         struct pxa_i2c *i2c = adap->algo_data;
949         int ret, i;
950
951         for (i = adap->retries; i >= 0; i--) {
952                 ret = i2c_pxa_do_xfer(i2c, msgs, num);
953                 if (ret != I2C_RETRY)
954                         goto out;
955
956                 if (i2c_debug)
957                         dev_dbg(&adap->dev, "Retrying transmission\n");
958                 udelay(100);
959         }
960         i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
961         ret = -EREMOTEIO;
962  out:
963         i2c_pxa_set_slave(i2c, ret);
964         return ret;
965 }
966
967 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
968 {
969         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
970 }
971
972 static const struct i2c_algorithm i2c_pxa_algorithm = {
973         .master_xfer    = i2c_pxa_xfer,
974         .functionality  = i2c_pxa_functionality,
975 };
976
977 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
978         .master_xfer    = i2c_pxa_pio_xfer,
979         .functionality  = i2c_pxa_functionality,
980 };
981
982 #define res_len(r)              ((r)->end - (r)->start + 1)
983 static int i2c_pxa_probe(struct platform_device *dev)
984 {
985         struct pxa_i2c *i2c;
986         struct resource *res;
987         struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
988         int ret;
989         int irq;
990
991         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
992         irq = platform_get_irq(dev, 0);
993         if (res == NULL || irq < 0)
994                 return -ENODEV;
995
996         if (!request_mem_region(res->start, res_len(res), res->name))
997                 return -ENOMEM;
998
999         i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
1000         if (!i2c) {
1001                 ret = -ENOMEM;
1002                 goto emalloc;
1003         }
1004
1005         i2c->adap.owner   = THIS_MODULE;
1006         i2c->adap.retries = 5;
1007
1008         spin_lock_init(&i2c->lock);
1009         init_waitqueue_head(&i2c->wait);
1010
1011         /*
1012          * If "dev->id" is negative we consider it as zero.
1013          * The reason to do so is to avoid sysfs names that only make
1014          * sense when there are multiple adapters.
1015          */
1016         i2c->adap.nr = dev->id != -1 ? dev->id : 0;
1017         snprintf(i2c->adap.name, sizeof(i2c->adap.name), "pxa_i2c-i2c.%u",
1018                  i2c->adap.nr);
1019
1020         i2c->clk = clk_get(&dev->dev, NULL);
1021         if (IS_ERR(i2c->clk)) {
1022                 ret = PTR_ERR(i2c->clk);
1023                 goto eclk;
1024         }
1025
1026         i2c->reg_base = ioremap(res->start, res_len(res));
1027         if (!i2c->reg_base) {
1028                 ret = -EIO;
1029                 goto eremap;
1030         }
1031         i2c->reg_shift = (cpu_is_pxa3xx() && (dev->id == 1)) ? 0 : 1;
1032
1033         i2c->iobase = res->start;
1034         i2c->iosize = res_len(res);
1035
1036         i2c->irq = irq;
1037
1038         i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1039
1040 #ifdef CONFIG_I2C_PXA_SLAVE
1041         if (plat) {
1042                 i2c->slave_addr = plat->slave_addr;
1043                 i2c->slave = plat->slave;
1044         }
1045 #endif
1046
1047         clk_enable(i2c->clk);
1048
1049         if (plat) {
1050                 i2c->adap.class = plat->class;
1051                 i2c->use_pio = plat->use_pio;
1052                 i2c->fast_mode = plat->fast_mode;
1053         }
1054
1055         if (i2c->use_pio) {
1056                 i2c->adap.algo = &i2c_pxa_pio_algorithm;
1057         } else {
1058                 i2c->adap.algo = &i2c_pxa_algorithm;
1059                 ret = request_irq(irq, i2c_pxa_handler, IRQF_DISABLED,
1060                                   i2c->adap.name, i2c);
1061                 if (ret)
1062                         goto ereqirq;
1063         }
1064
1065         i2c_pxa_reset(i2c);
1066
1067         i2c->adap.algo_data = i2c;
1068         i2c->adap.dev.parent = &dev->dev;
1069
1070         ret = i2c_add_numbered_adapter(&i2c->adap);
1071         if (ret < 0) {
1072                 printk(KERN_INFO "I2C: Failed to add bus\n");
1073                 goto eadapt;
1074         }
1075
1076         platform_set_drvdata(dev, i2c);
1077
1078 #ifdef CONFIG_I2C_PXA_SLAVE
1079         printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
1080                dev_name(&i2c->adap.dev), i2c->slave_addr);
1081 #else
1082         printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
1083                dev_name(&i2c->adap.dev));
1084 #endif
1085         return 0;
1086
1087 eadapt:
1088         if (!i2c->use_pio)
1089                 free_irq(irq, i2c);
1090 ereqirq:
1091         clk_disable(i2c->clk);
1092         iounmap(i2c->reg_base);
1093 eremap:
1094         clk_put(i2c->clk);
1095 eclk:
1096         kfree(i2c);
1097 emalloc:
1098         release_mem_region(res->start, res_len(res));
1099         return ret;
1100 }
1101
1102 static int __exit i2c_pxa_remove(struct platform_device *dev)
1103 {
1104         struct pxa_i2c *i2c = platform_get_drvdata(dev);
1105
1106         platform_set_drvdata(dev, NULL);
1107
1108         i2c_del_adapter(&i2c->adap);
1109         if (!i2c->use_pio)
1110                 free_irq(i2c->irq, i2c);
1111
1112         clk_disable(i2c->clk);
1113         clk_put(i2c->clk);
1114
1115         iounmap(i2c->reg_base);
1116         release_mem_region(i2c->iobase, i2c->iosize);
1117         kfree(i2c);
1118
1119         return 0;
1120 }
1121
1122 #ifdef CONFIG_PM
1123 static int i2c_pxa_suspend_late(struct platform_device *dev, pm_message_t state)
1124 {
1125         struct pxa_i2c *i2c = platform_get_drvdata(dev);
1126         clk_disable(i2c->clk);
1127         return 0;
1128 }
1129
1130 static int i2c_pxa_resume_early(struct platform_device *dev)
1131 {
1132         struct pxa_i2c *i2c = platform_get_drvdata(dev);
1133
1134         clk_enable(i2c->clk);
1135         i2c_pxa_reset(i2c);
1136
1137         return 0;
1138 }
1139 #else
1140 #define i2c_pxa_suspend_late NULL
1141 #define i2c_pxa_resume_early NULL
1142 #endif
1143
1144 static struct platform_driver i2c_pxa_driver = {
1145         .probe          = i2c_pxa_probe,
1146         .remove         = __exit_p(i2c_pxa_remove),
1147         .suspend_late   = i2c_pxa_suspend_late,
1148         .resume_early   = i2c_pxa_resume_early,
1149         .driver         = {
1150                 .name   = "pxa2xx-i2c",
1151                 .owner  = THIS_MODULE,
1152         },
1153 };
1154
1155 static int __init i2c_adap_pxa_init(void)
1156 {
1157         return platform_driver_register(&i2c_pxa_driver);
1158 }
1159
1160 static void __exit i2c_adap_pxa_exit(void)
1161 {
1162         platform_driver_unregister(&i2c_pxa_driver);
1163 }
1164
1165 MODULE_LICENSE("GPL");
1166 MODULE_ALIAS("platform:pxa2xx-i2c");
1167
1168 subsys_initcall(i2c_adap_pxa_init);
1169 module_exit(i2c_adap_pxa_exit);