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Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6/linux-2.6-openrd.git] / drivers / i2c / busses / i2c-pxa.c
blob7647a20523a02dc01ccd58b5ed777448f00e57f6
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 <asm/irq.h>
38 #include <asm/io.h>
39 #include <plat/i2c.h>
40
41 /*
42 * I2C register offsets will be shifted 0 or 1 bit left, depending on
43 * different SoCs
44 */
45 #define REG_SHIFT_0 (0 << 0)
46 #define REG_SHIFT_1 (1 << 0)
47 #define REG_SHIFT(d) ((d) & 0x1)
48
49 static const struct platform_device_id i2c_pxa_id_table[] = {
50 { "pxa2xx-i2c", REG_SHIFT_1 },
51 { "pxa3xx-pwri2c", REG_SHIFT_0 },
52 { },
53 };
54 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
55
56 /*
57 * I2C registers and bit definitions
58 */
59 #define IBMR (0x00)
60 #define IDBR (0x08)
61 #define ICR (0x10)
62 #define ISR (0x18)
63 #define ISAR (0x20)
64
65 #define ICR_START (1 << 0) /* start bit */
66 #define ICR_STOP (1 << 1) /* stop bit */
67 #define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
68 #define ICR_TB (1 << 3) /* transfer byte bit */
69 #define ICR_MA (1 << 4) /* master abort */
70 #define ICR_SCLE (1 << 5) /* master clock enable */
71 #define ICR_IUE (1 << 6) /* unit enable */
72 #define ICR_GCD (1 << 7) /* general call disable */
73 #define ICR_ITEIE (1 << 8) /* enable tx interrupts */
74 #define ICR_IRFIE (1 << 9) /* enable rx interrupts */
75 #define ICR_BEIE (1 << 10) /* enable bus error ints */
76 #define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
77 #define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
78 #define ICR_SADIE (1 << 13) /* slave address detected int enable */
79 #define ICR_UR (1 << 14) /* unit reset */
80 #define ICR_FM (1 << 15) /* fast mode */
81
82 #define ISR_RWM (1 << 0) /* read/write mode */
83 #define ISR_ACKNAK (1 << 1) /* ack/nak status */
84 #define ISR_UB (1 << 2) /* unit busy */
85 #define ISR_IBB (1 << 3) /* bus busy */
86 #define ISR_SSD (1 << 4) /* slave stop detected */
87 #define ISR_ALD (1 << 5) /* arbitration loss detected */
88 #define ISR_ITE (1 << 6) /* tx buffer empty */
89 #define ISR_IRF (1 << 7) /* rx buffer full */
90 #define ISR_GCAD (1 << 8) /* general call address detected */
91 #define ISR_SAD (1 << 9) /* slave address detected */
92 #define ISR_BED (1 << 10) /* bus error no ACK/NAK */
93
94 struct pxa_i2c {
95 spinlock_t lock;
96 wait_queue_head_t wait;
97 struct i2c_msg *msg;
98 unsigned int msg_num;
99 unsigned int msg_idx;
100 unsigned int msg_ptr;
101 unsigned int slave_addr;
102
103 struct i2c_adapter adap;
104 struct clk *clk;
105 #ifdef CONFIG_I2C_PXA_SLAVE
106 struct i2c_slave_client *slave;
107 #endif
108
109 unsigned int irqlogidx;
110 u32 isrlog[32];
111 u32 icrlog[32];
112
113 void __iomem *reg_base;
114 unsigned int reg_shift;
115
116 unsigned long iobase;
117 unsigned long iosize;
118
119 int irq;
120 unsigned int use_pio :1;
121 unsigned int fast_mode :1;
122 };
123
124 #define _IBMR(i2c) ((i2c)->reg_base + (0x0 << (i2c)->reg_shift))
125 #define _IDBR(i2c) ((i2c)->reg_base + (0x4 << (i2c)->reg_shift))
126 #define _ICR(i2c) ((i2c)->reg_base + (0x8 << (i2c)->reg_shift))
127 #define _ISR(i2c) ((i2c)->reg_base + (0xc << (i2c)->reg_shift))
128 #define _ISAR(i2c) ((i2c)->reg_base + (0x10 << (i2c)->reg_shift))
129
130 /*
131 * I2C Slave mode address
132 */
133 #define I2C_PXA_SLAVE_ADDR 0x1
134
135 #ifdef DEBUG
136
137 struct bits {
138 u32 mask;
139 const char *set;
140 const char *unset;
141 };
142 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
143
144 static inline void
145 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
146 {
147 printk("%s %08x: ", prefix, val);
148 while (num--) {
149 const char *str = val & bits->mask ? bits->set : bits->unset;
150 if (str)
151 printk("%s ", str);
152 bits++;
153 }
154 }
155
156 static const struct bits isr_bits[] = {
157 PXA_BIT(ISR_RWM, "RX", "TX"),
158 PXA_BIT(ISR_ACKNAK, "NAK", "ACK"),
159 PXA_BIT(ISR_UB, "Bsy", "Rdy"),
160 PXA_BIT(ISR_IBB, "BusBsy", "BusRdy"),
161 PXA_BIT(ISR_SSD, "SlaveStop", NULL),
162 PXA_BIT(ISR_ALD, "ALD", NULL),
163 PXA_BIT(ISR_ITE, "TxEmpty", NULL),
164 PXA_BIT(ISR_IRF, "RxFull", NULL),
165 PXA_BIT(ISR_GCAD, "GenCall", NULL),
166 PXA_BIT(ISR_SAD, "SlaveAddr", NULL),
167 PXA_BIT(ISR_BED, "BusErr", NULL),
168 };
169
170 static void decode_ISR(unsigned int val)
171 {
172 decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
173 printk("\n");
174 }
175
176 static const struct bits icr_bits[] = {
177 PXA_BIT(ICR_START, "START", NULL),
178 PXA_BIT(ICR_STOP, "STOP", NULL),
179 PXA_BIT(ICR_ACKNAK, "ACKNAK", NULL),
180 PXA_BIT(ICR_TB, "TB", NULL),
181 PXA_BIT(ICR_MA, "MA", NULL),
182 PXA_BIT(ICR_SCLE, "SCLE", "scle"),
183 PXA_BIT(ICR_IUE, "IUE", "iue"),
184 PXA_BIT(ICR_GCD, "GCD", NULL),
185 PXA_BIT(ICR_ITEIE, "ITEIE", NULL),
186 PXA_BIT(ICR_IRFIE, "IRFIE", NULL),
187 PXA_BIT(ICR_BEIE, "BEIE", NULL),
188 PXA_BIT(ICR_SSDIE, "SSDIE", NULL),
189 PXA_BIT(ICR_ALDIE, "ALDIE", NULL),
190 PXA_BIT(ICR_SADIE, "SADIE", NULL),
191 PXA_BIT(ICR_UR, "UR", "ur"),
192 };
193
194 #ifdef CONFIG_I2C_PXA_SLAVE
195 static void decode_ICR(unsigned int val)
196 {
197 decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
198 printk("\n");
199 }
200 #endif
201
202 static unsigned int i2c_debug = DEBUG;
203
204 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
205 {
206 dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
207 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
208 }
209
210 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
211 #else
212 #define i2c_debug 0
213
214 #define show_state(i2c) do { } while (0)
215 #define decode_ISR(val) do { } while (0)
216 #define decode_ICR(val) do { } while (0)
217 #endif
218
219 #define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
220
221 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
222 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
223
224 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
225 {
226 unsigned int i;
227 printk(KERN_ERR "i2c: error: %s\n", why);
228 printk(KERN_ERR "i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
229 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
230 printk(KERN_ERR "i2c: ICR: %08x ISR: %08x\n",
231 readl(_ICR(i2c)), readl(_ISR(i2c)));
232 printk(KERN_DEBUG "i2c: log: ");
233 for (i = 0; i < i2c->irqlogidx; i++)
234 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
235 printk("\n");
236 }
237
238 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
239 {
240 return !(readl(_ICR(i2c)) & ICR_SCLE);
241 }
242
243 static void i2c_pxa_abort(struct pxa_i2c *i2c)
244 {
245 int i = 250;
246
247 if (i2c_pxa_is_slavemode(i2c)) {
248 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
249 return;
250 }
251
252 while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
253 unsigned long icr = readl(_ICR(i2c));
254
255 icr &= ~ICR_START;
256 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
257
258 writel(icr, _ICR(i2c));
259
260 show_state(i2c);
261
262 mdelay(1);
263 i --;
264 }
265
266 writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
267 _ICR(i2c));
268 }
269
270 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
271 {
272 int timeout = DEF_TIMEOUT;
273
274 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
275 if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
276 timeout += 4;
277
278 msleep(2);
279 show_state(i2c);
280 }
281
282 if (timeout < 0)
283 show_state(i2c);
284
285 return timeout < 0 ? I2C_RETRY : 0;
286 }
287
288 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
289 {
290 unsigned long timeout = jiffies + HZ*4;
291
292 while (time_before(jiffies, timeout)) {
293 if (i2c_debug > 1)
294 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
295 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
296
297 if (readl(_ISR(i2c)) & ISR_SAD) {
298 if (i2c_debug > 0)
299 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
300 goto out;
301 }
302
303 /* wait for unit and bus being not busy, and we also do a
304 * quick check of the i2c lines themselves to ensure they've
305 * gone high...
306 */
307 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
308 if (i2c_debug > 0)
309 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
310 return 1;
311 }
312
313 msleep(1);
314 }
315
316 if (i2c_debug > 0)
317 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
318 out:
319 return 0;
320 }
321
322 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
323 {
324 if (i2c_debug)
325 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
326
327 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
328 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
329 if (!i2c_pxa_wait_master(i2c)) {
330 dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
331 return I2C_RETRY;
332 }
333 }
334
335 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
336 return 0;
337 }
338
339 #ifdef CONFIG_I2C_PXA_SLAVE
340 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
341 {
342 unsigned long timeout = jiffies + HZ*1;
343
344 /* wait for stop */
345
346 show_state(i2c);
347
348 while (time_before(jiffies, timeout)) {
349 if (i2c_debug > 1)
350 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
351 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
352
353 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
354 (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
355 (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
356 if (i2c_debug > 1)
357 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
358 return 1;
359 }
360
361 msleep(1);
362 }
363
364 if (i2c_debug > 0)
365 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
366 return 0;
367 }
368
369 /*
370 * clear the hold on the bus, and take of anything else
371 * that has been configured
372 */
373 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
374 {
375 show_state(i2c);
376
377 if (errcode < 0) {
378 udelay(100); /* simple delay */
379 } else {
380 /* we need to wait for the stop condition to end */
381
382 /* if we where in stop, then clear... */
383 if (readl(_ICR(i2c)) & ICR_STOP) {
384 udelay(100);
385 writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
386 }
387
388 if (!i2c_pxa_wait_slave(i2c)) {
389 dev_err(&i2c->adap.dev, "%s: wait timedout\n",
390 __func__);
391 return;
392 }
393 }
394
395 writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
396 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
397
398 if (i2c_debug) {
399 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
400 decode_ICR(readl(_ICR(i2c)));
401 }
402 }
403 #else
404 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
405 #endif
406
407 static void i2c_pxa_reset(struct pxa_i2c *i2c)
408 {
409 pr_debug("Resetting I2C Controller Unit\n");
410
411 /* abort any transfer currently under way */
412 i2c_pxa_abort(i2c);
413
414 /* reset according to 9.8 */
415 writel(ICR_UR, _ICR(i2c));
416 writel(I2C_ISR_INIT, _ISR(i2c));
417 writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
418
419 writel(i2c->slave_addr, _ISAR(i2c));
420
421 /* set control register values */
422 writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
423
424 #ifdef CONFIG_I2C_PXA_SLAVE
425 dev_info(&i2c->adap.dev, "Enabling slave mode\n");
426 writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
427 #endif
428
429 i2c_pxa_set_slave(i2c, 0);
430
431 /* enable unit */
432 writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
433 udelay(100);
434 }
435
436
437 #ifdef CONFIG_I2C_PXA_SLAVE
438 /*
439 * PXA I2C Slave mode
440 */
441
442 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
443 {
444 if (isr & ISR_BED) {
445 /* what should we do here? */
446 } else {
447 int ret = 0;
448
449 if (i2c->slave != NULL)
450 ret = i2c->slave->read(i2c->slave->data);
451
452 writel(ret, _IDBR(i2c));
453 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */
454 }
455 }
456
457 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
458 {
459 unsigned int byte = readl(_IDBR(i2c));
460
461 if (i2c->slave != NULL)
462 i2c->slave->write(i2c->slave->data, byte);
463
464 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
465 }
466
467 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
468 {
469 int timeout;
470
471 if (i2c_debug > 0)
472 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
473 (isr & ISR_RWM) ? 'r' : 't');
474
475 if (i2c->slave != NULL)
476 i2c->slave->event(i2c->slave->data,
477 (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
478
479 /*
480 * slave could interrupt in the middle of us generating a
481 * start condition... if this happens, we'd better back off
482 * and stop holding the poor thing up
483 */
484 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
485 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
486
487 timeout = 0x10000;
488
489 while (1) {
490 if ((readl(_IBMR(i2c)) & 2) == 2)
491 break;
492
493 timeout--;
494
495 if (timeout <= 0) {
496 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
497 break;
498 }
499 }
500
501 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
502 }
503
504 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
505 {
506 if (i2c_debug > 2)
507 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
508
509 if (i2c->slave != NULL)
510 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
511
512 if (i2c_debug > 2)
513 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
514
515 /*
516 * If we have a master-mode message waiting,
517 * kick it off now that the slave has completed.
518 */
519 if (i2c->msg)
520 i2c_pxa_master_complete(i2c, I2C_RETRY);
521 }
522 #else
523 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
524 {
525 if (isr & ISR_BED) {
526 /* what should we do here? */
527 } else {
528 writel(0, _IDBR(i2c));
529 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
530 }
531 }
532
533 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
534 {
535 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
536 }
537
538 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
539 {
540 int timeout;
541
542 /*
543 * slave could interrupt in the middle of us generating a
544 * start condition... if this happens, we'd better back off
545 * and stop holding the poor thing up
546 */
547 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
548 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
549
550 timeout = 0x10000;
551
552 while (1) {
553 if ((readl(_IBMR(i2c)) & 2) == 2)
554 break;
555
556 timeout--;
557
558 if (timeout <= 0) {
559 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
560 break;
561 }
562 }
563
564 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
565 }
566
567 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
568 {
569 if (i2c->msg)
570 i2c_pxa_master_complete(i2c, I2C_RETRY);
571 }
572 #endif
573
574 /*
575 * PXA I2C Master mode
576 */
577
578 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
579 {
580 unsigned int addr = (msg->addr & 0x7f) << 1;
581
582 if (msg->flags & I2C_M_RD)
583 addr |= 1;
584
585 return addr;
586 }
587
588 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
589 {
590 u32 icr;
591
592 /*
593 * Step 1: target slave address into IDBR
594 */
595 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
596
597 /*
598 * Step 2: initiate the write.
599 */
600 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
601 writel(icr | ICR_START | ICR_TB, _ICR(i2c));
602 }
603
604 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
605 {
606 u32 icr;
607
608 /*
609 * Clear the STOP and ACK flags
610 */
611 icr = readl(_ICR(i2c));
612 icr &= ~(ICR_STOP | ICR_ACKNAK);
613 writel(icr, _ICR(i2c));
614 }
615
616 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
617 {
618 /* make timeout the same as for interrupt based functions */
619 long timeout = 2 * DEF_TIMEOUT;
620
621 /*
622 * Wait for the bus to become free.
623 */
624 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
625 udelay(1000);
626 show_state(i2c);
627 }
628
629 if (timeout < 0) {
630 show_state(i2c);
631 dev_err(&i2c->adap.dev,
632 "i2c_pxa: timeout waiting for bus free\n");
633 return I2C_RETRY;
634 }
635
636 /*
637 * Set master mode.
638 */
639 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
640
641 return 0;
642 }
643
644 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
645 struct i2c_msg *msg, int num)
646 {
647 unsigned long timeout = 500000; /* 5 seconds */
648 int ret = 0;
649
650 ret = i2c_pxa_pio_set_master(i2c);
651 if (ret)
652 goto out;
653
654 i2c->msg = msg;
655 i2c->msg_num = num;
656 i2c->msg_idx = 0;
657 i2c->msg_ptr = 0;
658 i2c->irqlogidx = 0;
659
660 i2c_pxa_start_message(i2c);
661
662 while (i2c->msg_num > 0 && --timeout) {
663 i2c_pxa_handler(0, i2c);
664 udelay(10);
665 }
666
667 i2c_pxa_stop_message(i2c);
668
669 /*
670 * We place the return code in i2c->msg_idx.
671 */
672 ret = i2c->msg_idx;
673
674 out:
675 if (timeout == 0)
676 i2c_pxa_scream_blue_murder(i2c, "timeout");
677
678 return ret;
679 }
680
681 /*
682 * We are protected by the adapter bus mutex.
683 */
684 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
685 {
686 long timeout;
687 int ret;
688
689 /*
690 * Wait for the bus to become free.
691 */
692 ret = i2c_pxa_wait_bus_not_busy(i2c);
693 if (ret) {
694 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
695 goto out;
696 }
697
698 /*
699 * Set master mode.
700 */
701 ret = i2c_pxa_set_master(i2c);
702 if (ret) {
703 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
704 goto out;
705 }
706
707 spin_lock_irq(&i2c->lock);
708
709 i2c->msg = msg;
710 i2c->msg_num = num;
711 i2c->msg_idx = 0;
712 i2c->msg_ptr = 0;
713 i2c->irqlogidx = 0;
714
715 i2c_pxa_start_message(i2c);
716
717 spin_unlock_irq(&i2c->lock);
718
719 /*
720 * The rest of the processing occurs in the interrupt handler.
721 */
722 timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
723 i2c_pxa_stop_message(i2c);
724
725 /*
726 * We place the return code in i2c->msg_idx.
727 */
728 ret = i2c->msg_idx;
729
730 if (timeout == 0)
731 i2c_pxa_scream_blue_murder(i2c, "timeout");
732
733 out:
734 return ret;
735 }
736
737 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
738 struct i2c_msg msgs[], int num)
739 {
740 struct pxa_i2c *i2c = adap->algo_data;
741 int ret, i;
742
743 /* If the I2C controller is disabled we need to reset it
744 (probably due to a suspend/resume destroying state). We do
745 this here as we can then avoid worrying about resuming the
746 controller before its users. */
747 if (!(readl(_ICR(i2c)) & ICR_IUE))
748 i2c_pxa_reset(i2c);
749
750 for (i = adap->retries; i >= 0; i--) {
751 ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
752 if (ret != I2C_RETRY)
753 goto out;
754
755 if (i2c_debug)
756 dev_dbg(&adap->dev, "Retrying transmission\n");
757 udelay(100);
758 }
759 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
760 ret = -EREMOTEIO;
761 out:
762 i2c_pxa_set_slave(i2c, ret);
763 return ret;
764 }
765
766 /*
767 * i2c_pxa_master_complete - complete the message and wake up.
768 */
769 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
770 {
771 i2c->msg_ptr = 0;
772 i2c->msg = NULL;
773 i2c->msg_idx ++;
774 i2c->msg_num = 0;
775 if (ret)
776 i2c->msg_idx = ret;
777 if (!i2c->use_pio)
778 wake_up(&i2c->wait);
779 }
780
781 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
782 {
783 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
784
785 again:
786 /*
787 * If ISR_ALD is set, we lost arbitration.
788 */
789 if (isr & ISR_ALD) {
790 /*
791 * Do we need to do anything here? The PXA docs
792 * are vague about what happens.
793 */
794 i2c_pxa_scream_blue_murder(i2c, "ALD set");
795
796 /*
797 * We ignore this error. We seem to see spurious ALDs
798 * for seemingly no reason. If we handle them as I think
799 * they should, we end up causing an I2C error, which
800 * is painful for some systems.
801 */
802 return; /* ignore */
803 }
804
805 if (isr & ISR_BED) {
806 int ret = BUS_ERROR;
807
808 /*
809 * I2C bus error - either the device NAK'd us, or
810 * something more serious happened. If we were NAK'd
811 * on the initial address phase, we can retry.
812 */
813 if (isr & ISR_ACKNAK) {
814 if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
815 ret = I2C_RETRY;
816 else
817 ret = XFER_NAKED;
818 }
819 i2c_pxa_master_complete(i2c, ret);
820 } else if (isr & ISR_RWM) {
821 /*
822 * Read mode. We have just sent the address byte, and
823 * now we must initiate the transfer.
824 */
825 if (i2c->msg_ptr == i2c->msg->len - 1 &&
826 i2c->msg_idx == i2c->msg_num - 1)
827 icr |= ICR_STOP | ICR_ACKNAK;
828
829 icr |= ICR_ALDIE | ICR_TB;
830 } else if (i2c->msg_ptr < i2c->msg->len) {
831 /*
832 * Write mode. Write the next data byte.
833 */
834 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
835
836 icr |= ICR_ALDIE | ICR_TB;
837
838 /*
839 * If this is the last byte of the last message, send
840 * a STOP.
841 */
842 if (i2c->msg_ptr == i2c->msg->len &&
843 i2c->msg_idx == i2c->msg_num - 1)
844 icr |= ICR_STOP;
845 } else if (i2c->msg_idx < i2c->msg_num - 1) {
846 /*
847 * Next segment of the message.
848 */
849 i2c->msg_ptr = 0;
850 i2c->msg_idx ++;
851 i2c->msg++;
852
853 /*
854 * If we aren't doing a repeated start and address,
855 * go back and try to send the next byte. Note that
856 * we do not support switching the R/W direction here.
857 */
858 if (i2c->msg->flags & I2C_M_NOSTART)
859 goto again;
860
861 /*
862 * Write the next address.
863 */
864 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
865
866 /*
867 * And trigger a repeated start, and send the byte.
868 */
869 icr &= ~ICR_ALDIE;
870 icr |= ICR_START | ICR_TB;
871 } else {
872 if (i2c->msg->len == 0) {
873 /*
874 * Device probes have a message length of zero
875 * and need the bus to be reset before it can
876 * be used again.
877 */
878 i2c_pxa_reset(i2c);
879 }
880 i2c_pxa_master_complete(i2c, 0);
881 }
882
883 i2c->icrlog[i2c->irqlogidx-1] = icr;
884
885 writel(icr, _ICR(i2c));
886 show_state(i2c);
887 }
888
889 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
890 {
891 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
892
893 /*
894 * Read the byte.
895 */
896 i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
897
898 if (i2c->msg_ptr < i2c->msg->len) {
899 /*
900 * If this is the last byte of the last
901 * message, send a STOP.
902 */
903 if (i2c->msg_ptr == i2c->msg->len - 1)
904 icr |= ICR_STOP | ICR_ACKNAK;
905
906 icr |= ICR_ALDIE | ICR_TB;
907 } else {
908 i2c_pxa_master_complete(i2c, 0);
909 }
910
911 i2c->icrlog[i2c->irqlogidx-1] = icr;
912
913 writel(icr, _ICR(i2c));
914 }
915
916 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
917 {
918 struct pxa_i2c *i2c = dev_id;
919 u32 isr = readl(_ISR(i2c));
920
921 if (i2c_debug > 2 && 0) {
922 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
923 __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
924 decode_ISR(isr);
925 }
926
927 if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
928 i2c->isrlog[i2c->irqlogidx++] = isr;
929
930 show_state(i2c);
931
932 /*
933 * Always clear all pending IRQs.
934 */
935 writel(isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED), _ISR(i2c));
936
937 if (isr & ISR_SAD)
938 i2c_pxa_slave_start(i2c, isr);
939 if (isr & ISR_SSD)
940 i2c_pxa_slave_stop(i2c);
941
942 if (i2c_pxa_is_slavemode(i2c)) {
943 if (isr & ISR_ITE)
944 i2c_pxa_slave_txempty(i2c, isr);
945 if (isr & ISR_IRF)
946 i2c_pxa_slave_rxfull(i2c, isr);
947 } else if (i2c->msg) {
948 if (isr & ISR_ITE)
949 i2c_pxa_irq_txempty(i2c, isr);
950 if (isr & ISR_IRF)
951 i2c_pxa_irq_rxfull(i2c, isr);
952 } else {
953 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
954 }
955
956 return IRQ_HANDLED;
957 }
958
959
960 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
961 {
962 struct pxa_i2c *i2c = adap->algo_data;
963 int ret, i;
964
965 for (i = adap->retries; i >= 0; i--) {
966 ret = i2c_pxa_do_xfer(i2c, msgs, num);
967 if (ret != I2C_RETRY)
968 goto out;
969
970 if (i2c_debug)
971 dev_dbg(&adap->dev, "Retrying transmission\n");
972 udelay(100);
973 }
974 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
975 ret = -EREMOTEIO;
976 out:
977 i2c_pxa_set_slave(i2c, ret);
978 return ret;
979 }
980
981 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
982 {
983 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
984 }
985
986 static const struct i2c_algorithm i2c_pxa_algorithm = {
987 .master_xfer = i2c_pxa_xfer,
988 .functionality = i2c_pxa_functionality,
989 };
990
991 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
992 .master_xfer = i2c_pxa_pio_xfer,
993 .functionality = i2c_pxa_functionality,
994 };
995
996 static int i2c_pxa_probe(struct platform_device *dev)
997 {
998 struct pxa_i2c *i2c;
999 struct resource *res;
1000 struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
1001 struct platform_device_id *id = platform_get_device_id(dev);
1002 int ret;
1003 int irq;
1004
1005 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
1006 irq = platform_get_irq(dev, 0);
1007 if (res == NULL || irq < 0)
1008 return -ENODEV;
1009
1010 if (!request_mem_region(res->start, resource_size(res), res->name))
1011 return -ENOMEM;
1012
1013 i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
1014 if (!i2c) {
1015 ret = -ENOMEM;
1016 goto emalloc;
1017 }
1018
1019 i2c->adap.owner = THIS_MODULE;
1020 i2c->adap.retries = 5;
1021
1022 spin_lock_init(&i2c->lock);
1023 init_waitqueue_head(&i2c->wait);
1024
1025 /*
1026 * If "dev->id" is negative we consider it as zero.
1027 * The reason to do so is to avoid sysfs names that only make
1028 * sense when there are multiple adapters.
1029 */
1030 i2c->adap.nr = dev->id != -1 ? dev->id : 0;
1031 snprintf(i2c->adap.name, sizeof(i2c->adap.name), "pxa_i2c-i2c.%u",
1032 i2c->adap.nr);
1033
1034 i2c->clk = clk_get(&dev->dev, NULL);
1035 if (IS_ERR(i2c->clk)) {
1036 ret = PTR_ERR(i2c->clk);
1037 goto eclk;
1038 }
1039
1040 i2c->reg_base = ioremap(res->start, resource_size(res));
1041 if (!i2c->reg_base) {
1042 ret = -EIO;
1043 goto eremap;
1044 }
1045 i2c->reg_shift = REG_SHIFT(id->driver_data);
1046
1047 i2c->iobase = res->start;
1048 i2c->iosize = resource_size(res);
1049
1050 i2c->irq = irq;
1051
1052 i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1053
1054 #ifdef CONFIG_I2C_PXA_SLAVE
1055 if (plat) {
1056 i2c->slave_addr = plat->slave_addr;
1057 i2c->slave = plat->slave;
1058 }
1059 #endif
1060
1061 clk_enable(i2c->clk);
1062
1063 if (plat) {
1064 i2c->adap.class = plat->class;
1065 i2c->use_pio = plat->use_pio;
1066 i2c->fast_mode = plat->fast_mode;
1067 }
1068
1069 if (i2c->use_pio) {
1070 i2c->adap.algo = &i2c_pxa_pio_algorithm;
1071 } else {
1072 i2c->adap.algo = &i2c_pxa_algorithm;
1073 ret = request_irq(irq, i2c_pxa_handler, IRQF_DISABLED,
1074 i2c->adap.name, i2c);
1075 if (ret)
1076 goto ereqirq;
1077 }
1078
1079 i2c_pxa_reset(i2c);
1080
1081 i2c->adap.algo_data = i2c;
1082 i2c->adap.dev.parent = &dev->dev;
1083
1084 ret = i2c_add_numbered_adapter(&i2c->adap);
1085 if (ret < 0) {
1086 printk(KERN_INFO "I2C: Failed to add bus\n");
1087 goto eadapt;
1088 }
1089
1090 platform_set_drvdata(dev, i2c);
1091
1092 #ifdef CONFIG_I2C_PXA_SLAVE
1093 printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
1094 dev_name(&i2c->adap.dev), i2c->slave_addr);
1095 #else
1096 printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
1097 dev_name(&i2c->adap.dev));
1098 #endif
1099 return 0;
1100
1101 eadapt:
1102 if (!i2c->use_pio)
1103 free_irq(irq, i2c);
1104 ereqirq:
1105 clk_disable(i2c->clk);
1106 iounmap(i2c->reg_base);
1107 eremap:
1108 clk_put(i2c->clk);
1109 eclk:
1110 kfree(i2c);
1111 emalloc:
1112 release_mem_region(res->start, resource_size(res));
1113 return ret;
1114 }
1115
1116 static int __exit i2c_pxa_remove(struct platform_device *dev)
1117 {
1118 struct pxa_i2c *i2c = platform_get_drvdata(dev);
1119
1120 platform_set_drvdata(dev, NULL);
1121
1122 i2c_del_adapter(&i2c->adap);
1123 if (!i2c->use_pio)
1124 free_irq(i2c->irq, i2c);
1125
1126 clk_disable(i2c->clk);
1127 clk_put(i2c->clk);
1128
1129 iounmap(i2c->reg_base);
1130 release_mem_region(i2c->iobase, i2c->iosize);
1131 kfree(i2c);
1132
1133 return 0;
1134 }
1135
1136 #ifdef CONFIG_PM
1137 static int i2c_pxa_suspend_noirq(struct device *dev)
1138 {
1139 struct platform_device *pdev = to_platform_device(dev);
1140 struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1141
1142 clk_disable(i2c->clk);
1143
1144 return 0;
1145 }
1146
1147 static int i2c_pxa_resume_noirq(struct device *dev)
1148 {
1149 struct platform_device *pdev = to_platform_device(dev);
1150 struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1151
1152 clk_enable(i2c->clk);
1153 i2c_pxa_reset(i2c);
1154
1155 return 0;
1156 }
1157
1158 static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
1159 .suspend_noirq = i2c_pxa_suspend_noirq,
1160 .resume_noirq = i2c_pxa_resume_noirq,
1161 };
1162
1163 #define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
1164 #else
1165 #define I2C_PXA_DEV_PM_OPS NULL
1166 #endif
1167
1168 static struct platform_driver i2c_pxa_driver = {
1169 .probe = i2c_pxa_probe,
1170 .remove = __exit_p(i2c_pxa_remove),
1171 .driver = {
1172 .name = "pxa2xx-i2c",
1173 .owner = THIS_MODULE,
1174 .pm = I2C_PXA_DEV_PM_OPS,
1175 },
1176 .id_table = i2c_pxa_id_table,
1177 };
1178
1179 static int __init i2c_adap_pxa_init(void)
1180 {
1181 return platform_driver_register(&i2c_pxa_driver);
1182 }
1183
1184 static void __exit i2c_adap_pxa_exit(void)
1185 {
1186 platform_driver_unregister(&i2c_pxa_driver);
1187 }
1188
1189 MODULE_LICENSE("GPL");
1190 MODULE_ALIAS("platform:pxa2xx-i2c");
1191
1192 subsys_initcall(i2c_adap_pxa_init);
1193 module_exit(i2c_adap_pxa_exit);
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