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i2c-pxa, rename BIT macro to PXA_BIT
[deliverable/linux.git] / 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 <asm/hardware.h>
38 #include <asm/irq.h>
39 #include <asm/io.h>
40 #include <asm/arch/i2c.h>
41 #include <asm/arch/pxa-regs.h>
42
43 struct pxa_i2c {
44 spinlock_t lock;
45 wait_queue_head_t wait;
46 struct i2c_msg *msg;
47 unsigned int msg_num;
48 unsigned int msg_idx;
49 unsigned int msg_ptr;
50 unsigned int slave_addr;
51
52 struct i2c_adapter adap;
53 struct clk *clk;
54 #ifdef CONFIG_I2C_PXA_SLAVE
55 struct i2c_slave_client *slave;
56 #endif
57
58 unsigned int irqlogidx;
59 u32 isrlog[32];
60 u32 icrlog[32];
61
62 void __iomem *reg_base;
63
64 unsigned long iobase;
65 unsigned long iosize;
66
67 int irq;
68 };
69
70 #define _IBMR(i2c) ((i2c)->reg_base + 0)
71 #define _IDBR(i2c) ((i2c)->reg_base + 8)
72 #define _ICR(i2c) ((i2c)->reg_base + 0x10)
73 #define _ISR(i2c) ((i2c)->reg_base + 0x18)
74 #define _ISAR(i2c) ((i2c)->reg_base + 0x20)
75
76 /*
77 * I2C Slave mode address
78 */
79 #define I2C_PXA_SLAVE_ADDR 0x1
80
81 #ifdef DEBUG
82
83 struct bits {
84 u32 mask;
85 const char *set;
86 const char *unset;
87 };
88 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
89
90 static inline void
91 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
92 {
93 printk("%s %08x: ", prefix, val);
94 while (num--) {
95 const char *str = val & bits->mask ? bits->set : bits->unset;
96 if (str)
97 printk("%s ", str);
98 bits++;
99 }
100 }
101
102 static const struct bits isr_bits[] = {
103 PXA_BIT(ISR_RWM, "RX", "TX"),
104 PXA_BIT(ISR_ACKNAK, "NAK", "ACK"),
105 PXA_BIT(ISR_UB, "Bsy", "Rdy"),
106 PXA_BIT(ISR_IBB, "BusBsy", "BusRdy"),
107 PXA_BIT(ISR_SSD, "SlaveStop", NULL),
108 PXA_BIT(ISR_ALD, "ALD", NULL),
109 PXA_BIT(ISR_ITE, "TxEmpty", NULL),
110 PXA_BIT(ISR_IRF, "RxFull", NULL),
111 PXA_BIT(ISR_GCAD, "GenCall", NULL),
112 PXA_BIT(ISR_SAD, "SlaveAddr", NULL),
113 PXA_BIT(ISR_BED, "BusErr", NULL),
114 };
115
116 static void decode_ISR(unsigned int val)
117 {
118 decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
119 printk("\n");
120 }
121
122 static const struct bits icr_bits[] = {
123 PXA_BIT(ICR_START, "START", NULL),
124 PXA_BIT(ICR_STOP, "STOP", NULL),
125 PXA_BIT(ICR_ACKNAK, "ACKNAK", NULL),
126 PXA_BIT(ICR_TB, "TB", NULL),
127 PXA_BIT(ICR_MA, "MA", NULL),
128 PXA_BIT(ICR_SCLE, "SCLE", "scle"),
129 PXA_BIT(ICR_IUE, "IUE", "iue"),
130 PXA_BIT(ICR_GCD, "GCD", NULL),
131 PXA_BIT(ICR_ITEIE, "ITEIE", NULL),
132 PXA_BIT(ICR_IRFIE, "IRFIE", NULL),
133 PXA_BIT(ICR_BEIE, "BEIE", NULL),
134 PXA_BIT(ICR_SSDIE, "SSDIE", NULL),
135 PXA_BIT(ICR_ALDIE, "ALDIE", NULL),
136 PXA_BIT(ICR_SADIE, "SADIE", NULL),
137 PXA_BIT(ICR_UR, "UR", "ur"),
138 };
139
140 static void decode_ICR(unsigned int val)
141 {
142 decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
143 printk("\n");
144 }
145
146 static unsigned int i2c_debug = DEBUG;
147
148 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
149 {
150 dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
151 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
152 }
153
154 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __FUNCTION__)
155 #else
156 #define i2c_debug 0
157
158 #define show_state(i2c) do { } while (0)
159 #define decode_ISR(val) do { } while (0)
160 #define decode_ICR(val) do { } while (0)
161 #endif
162
163 #define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
164
165 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
166
167 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
168 {
169 unsigned int i;
170 printk("i2c: error: %s\n", why);
171 printk("i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
172 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
173 printk("i2c: ICR: %08x ISR: %08x\n"
174 "i2c: log: ", readl(_ICR(i2c)), readl(_ISR(i2c)));
175 for (i = 0; i < i2c->irqlogidx; i++)
176 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
177 printk("\n");
178 }
179
180 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
181 {
182 return !(readl(_ICR(i2c)) & ICR_SCLE);
183 }
184
185 static void i2c_pxa_abort(struct pxa_i2c *i2c)
186 {
187 unsigned long timeout = jiffies + HZ/4;
188
189 if (i2c_pxa_is_slavemode(i2c)) {
190 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
191 return;
192 }
193
194 while (time_before(jiffies, timeout) && (readl(_IBMR(i2c)) & 0x1) == 0) {
195 unsigned long icr = readl(_ICR(i2c));
196
197 icr &= ~ICR_START;
198 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
199
200 writel(icr, _ICR(i2c));
201
202 show_state(i2c);
203
204 msleep(1);
205 }
206
207 writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
208 _ICR(i2c));
209 }
210
211 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
212 {
213 int timeout = DEF_TIMEOUT;
214
215 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
216 if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
217 timeout += 4;
218
219 msleep(2);
220 show_state(i2c);
221 }
222
223 if (timeout <= 0)
224 show_state(i2c);
225
226 return timeout <= 0 ? I2C_RETRY : 0;
227 }
228
229 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
230 {
231 unsigned long timeout = jiffies + HZ*4;
232
233 while (time_before(jiffies, timeout)) {
234 if (i2c_debug > 1)
235 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
236 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
237
238 if (readl(_ISR(i2c)) & ISR_SAD) {
239 if (i2c_debug > 0)
240 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
241 goto out;
242 }
243
244 /* wait for unit and bus being not busy, and we also do a
245 * quick check of the i2c lines themselves to ensure they've
246 * gone high...
247 */
248 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
249 if (i2c_debug > 0)
250 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
251 return 1;
252 }
253
254 msleep(1);
255 }
256
257 if (i2c_debug > 0)
258 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
259 out:
260 return 0;
261 }
262
263 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
264 {
265 if (i2c_debug)
266 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
267
268 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
269 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
270 if (!i2c_pxa_wait_master(i2c)) {
271 dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
272 return I2C_RETRY;
273 }
274 }
275
276 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
277 return 0;
278 }
279
280 #ifdef CONFIG_I2C_PXA_SLAVE
281 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
282 {
283 unsigned long timeout = jiffies + HZ*1;
284
285 /* wait for stop */
286
287 show_state(i2c);
288
289 while (time_before(jiffies, timeout)) {
290 if (i2c_debug > 1)
291 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
292 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
293
294 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
295 (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
296 (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
297 if (i2c_debug > 1)
298 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
299 return 1;
300 }
301
302 msleep(1);
303 }
304
305 if (i2c_debug > 0)
306 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
307 return 0;
308 }
309
310 /*
311 * clear the hold on the bus, and take of anything else
312 * that has been configured
313 */
314 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
315 {
316 show_state(i2c);
317
318 if (errcode < 0) {
319 udelay(100); /* simple delay */
320 } else {
321 /* we need to wait for the stop condition to end */
322
323 /* if we where in stop, then clear... */
324 if (readl(_ICR(i2c)) & ICR_STOP) {
325 udelay(100);
326 writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
327 }
328
329 if (!i2c_pxa_wait_slave(i2c)) {
330 dev_err(&i2c->adap.dev, "%s: wait timedout\n",
331 __func__);
332 return;
333 }
334 }
335
336 writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
337 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
338
339 if (i2c_debug) {
340 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
341 decode_ICR(readl(_ICR(i2c)));
342 }
343 }
344 #else
345 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
346 #endif
347
348 static void i2c_pxa_reset(struct pxa_i2c *i2c)
349 {
350 pr_debug("Resetting I2C Controller Unit\n");
351
352 /* abort any transfer currently under way */
353 i2c_pxa_abort(i2c);
354
355 /* reset according to 9.8 */
356 writel(ICR_UR, _ICR(i2c));
357 writel(I2C_ISR_INIT, _ISR(i2c));
358 writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
359
360 writel(i2c->slave_addr, _ISAR(i2c));
361
362 /* set control register values */
363 writel(I2C_ICR_INIT, _ICR(i2c));
364
365 #ifdef CONFIG_I2C_PXA_SLAVE
366 dev_info(&i2c->adap.dev, "Enabling slave mode\n");
367 writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
368 #endif
369
370 i2c_pxa_set_slave(i2c, 0);
371
372 /* enable unit */
373 writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
374 udelay(100);
375 }
376
377
378 #ifdef CONFIG_I2C_PXA_SLAVE
379 /*
380 * PXA I2C Slave mode
381 */
382
383 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
384 {
385 if (isr & ISR_BED) {
386 /* what should we do here? */
387 } else {
388 int ret = 0;
389
390 if (i2c->slave != NULL)
391 ret = i2c->slave->read(i2c->slave->data);
392
393 writel(ret, _IDBR(i2c));
394 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */
395 }
396 }
397
398 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
399 {
400 unsigned int byte = readl(_IDBR(i2c));
401
402 if (i2c->slave != NULL)
403 i2c->slave->write(i2c->slave->data, byte);
404
405 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
406 }
407
408 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
409 {
410 int timeout;
411
412 if (i2c_debug > 0)
413 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
414 (isr & ISR_RWM) ? 'r' : 't');
415
416 if (i2c->slave != NULL)
417 i2c->slave->event(i2c->slave->data,
418 (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
419
420 /*
421 * slave could interrupt in the middle of us generating a
422 * start condition... if this happens, we'd better back off
423 * and stop holding the poor thing up
424 */
425 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
426 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
427
428 timeout = 0x10000;
429
430 while (1) {
431 if ((readl(_IBMR(i2c)) & 2) == 2)
432 break;
433
434 timeout--;
435
436 if (timeout <= 0) {
437 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
438 break;
439 }
440 }
441
442 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
443 }
444
445 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
446 {
447 if (i2c_debug > 2)
448 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
449
450 if (i2c->slave != NULL)
451 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
452
453 if (i2c_debug > 2)
454 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
455
456 /*
457 * If we have a master-mode message waiting,
458 * kick it off now that the slave has completed.
459 */
460 if (i2c->msg)
461 i2c_pxa_master_complete(i2c, I2C_RETRY);
462 }
463 #else
464 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
465 {
466 if (isr & ISR_BED) {
467 /* what should we do here? */
468 } else {
469 writel(0, _IDBR(i2c));
470 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
471 }
472 }
473
474 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
475 {
476 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
477 }
478
479 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
480 {
481 int timeout;
482
483 /*
484 * slave could interrupt in the middle of us generating a
485 * start condition... if this happens, we'd better back off
486 * and stop holding the poor thing up
487 */
488 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
489 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
490
491 timeout = 0x10000;
492
493 while (1) {
494 if ((readl(_IBMR(i2c)) & 2) == 2)
495 break;
496
497 timeout--;
498
499 if (timeout <= 0) {
500 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
501 break;
502 }
503 }
504
505 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
506 }
507
508 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
509 {
510 if (i2c->msg)
511 i2c_pxa_master_complete(i2c, I2C_RETRY);
512 }
513 #endif
514
515 /*
516 * PXA I2C Master mode
517 */
518
519 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
520 {
521 unsigned int addr = (msg->addr & 0x7f) << 1;
522
523 if (msg->flags & I2C_M_RD)
524 addr |= 1;
525
526 return addr;
527 }
528
529 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
530 {
531 u32 icr;
532
533 /*
534 * Step 1: target slave address into IDBR
535 */
536 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
537
538 /*
539 * Step 2: initiate the write.
540 */
541 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
542 writel(icr | ICR_START | ICR_TB, _ICR(i2c));
543 }
544
545 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
546 {
547 u32 icr;
548
549 /*
550 * Clear the STOP and ACK flags
551 */
552 icr = readl(_ICR(i2c));
553 icr &= ~(ICR_STOP | ICR_ACKNAK);
554 writel(icr, _ICR(i2c));
555 }
556
557 /*
558 * We are protected by the adapter bus mutex.
559 */
560 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
561 {
562 long timeout;
563 int ret;
564
565 /*
566 * Wait for the bus to become free.
567 */
568 ret = i2c_pxa_wait_bus_not_busy(i2c);
569 if (ret) {
570 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
571 goto out;
572 }
573
574 /*
575 * Set master mode.
576 */
577 ret = i2c_pxa_set_master(i2c);
578 if (ret) {
579 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
580 goto out;
581 }
582
583 spin_lock_irq(&i2c->lock);
584
585 i2c->msg = msg;
586 i2c->msg_num = num;
587 i2c->msg_idx = 0;
588 i2c->msg_ptr = 0;
589 i2c->irqlogidx = 0;
590
591 i2c_pxa_start_message(i2c);
592
593 spin_unlock_irq(&i2c->lock);
594
595 /*
596 * The rest of the processing occurs in the interrupt handler.
597 */
598 timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
599 i2c_pxa_stop_message(i2c);
600
601 /*
602 * We place the return code in i2c->msg_idx.
603 */
604 ret = i2c->msg_idx;
605
606 if (timeout == 0)
607 i2c_pxa_scream_blue_murder(i2c, "timeout");
608
609 out:
610 return ret;
611 }
612
613 /*
614 * i2c_pxa_master_complete - complete the message and wake up.
615 */
616 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
617 {
618 i2c->msg_ptr = 0;
619 i2c->msg = NULL;
620 i2c->msg_idx ++;
621 i2c->msg_num = 0;
622 if (ret)
623 i2c->msg_idx = ret;
624 wake_up(&i2c->wait);
625 }
626
627 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
628 {
629 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
630
631 again:
632 /*
633 * If ISR_ALD is set, we lost arbitration.
634 */
635 if (isr & ISR_ALD) {
636 /*
637 * Do we need to do anything here? The PXA docs
638 * are vague about what happens.
639 */
640 i2c_pxa_scream_blue_murder(i2c, "ALD set");
641
642 /*
643 * We ignore this error. We seem to see spurious ALDs
644 * for seemingly no reason. If we handle them as I think
645 * they should, we end up causing an I2C error, which
646 * is painful for some systems.
647 */
648 return; /* ignore */
649 }
650
651 if (isr & ISR_BED) {
652 int ret = BUS_ERROR;
653
654 /*
655 * I2C bus error - either the device NAK'd us, or
656 * something more serious happened. If we were NAK'd
657 * on the initial address phase, we can retry.
658 */
659 if (isr & ISR_ACKNAK) {
660 if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
661 ret = I2C_RETRY;
662 else
663 ret = XFER_NAKED;
664 }
665 i2c_pxa_master_complete(i2c, ret);
666 } else if (isr & ISR_RWM) {
667 /*
668 * Read mode. We have just sent the address byte, and
669 * now we must initiate the transfer.
670 */
671 if (i2c->msg_ptr == i2c->msg->len - 1 &&
672 i2c->msg_idx == i2c->msg_num - 1)
673 icr |= ICR_STOP | ICR_ACKNAK;
674
675 icr |= ICR_ALDIE | ICR_TB;
676 } else if (i2c->msg_ptr < i2c->msg->len) {
677 /*
678 * Write mode. Write the next data byte.
679 */
680 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
681
682 icr |= ICR_ALDIE | ICR_TB;
683
684 /*
685 * If this is the last byte of the last message, send
686 * a STOP.
687 */
688 if (i2c->msg_ptr == i2c->msg->len &&
689 i2c->msg_idx == i2c->msg_num - 1)
690 icr |= ICR_STOP;
691 } else if (i2c->msg_idx < i2c->msg_num - 1) {
692 /*
693 * Next segment of the message.
694 */
695 i2c->msg_ptr = 0;
696 i2c->msg_idx ++;
697 i2c->msg++;
698
699 /*
700 * If we aren't doing a repeated start and address,
701 * go back and try to send the next byte. Note that
702 * we do not support switching the R/W direction here.
703 */
704 if (i2c->msg->flags & I2C_M_NOSTART)
705 goto again;
706
707 /*
708 * Write the next address.
709 */
710 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
711
712 /*
713 * And trigger a repeated start, and send the byte.
714 */
715 icr &= ~ICR_ALDIE;
716 icr |= ICR_START | ICR_TB;
717 } else {
718 if (i2c->msg->len == 0) {
719 /*
720 * Device probes have a message length of zero
721 * and need the bus to be reset before it can
722 * be used again.
723 */
724 i2c_pxa_reset(i2c);
725 }
726 i2c_pxa_master_complete(i2c, 0);
727 }
728
729 i2c->icrlog[i2c->irqlogidx-1] = icr;
730
731 writel(icr, _ICR(i2c));
732 show_state(i2c);
733 }
734
735 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
736 {
737 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
738
739 /*
740 * Read the byte.
741 */
742 i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
743
744 if (i2c->msg_ptr < i2c->msg->len) {
745 /*
746 * If this is the last byte of the last
747 * message, send a STOP.
748 */
749 if (i2c->msg_ptr == i2c->msg->len - 1)
750 icr |= ICR_STOP | ICR_ACKNAK;
751
752 icr |= ICR_ALDIE | ICR_TB;
753 } else {
754 i2c_pxa_master_complete(i2c, 0);
755 }
756
757 i2c->icrlog[i2c->irqlogidx-1] = icr;
758
759 writel(icr, _ICR(i2c));
760 }
761
762 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
763 {
764 struct pxa_i2c *i2c = dev_id;
765 u32 isr = readl(_ISR(i2c));
766
767 if (i2c_debug > 2 && 0) {
768 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
769 __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
770 decode_ISR(isr);
771 }
772
773 if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
774 i2c->isrlog[i2c->irqlogidx++] = isr;
775
776 show_state(i2c);
777
778 /*
779 * Always clear all pending IRQs.
780 */
781 writel(isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED), _ISR(i2c));
782
783 if (isr & ISR_SAD)
784 i2c_pxa_slave_start(i2c, isr);
785 if (isr & ISR_SSD)
786 i2c_pxa_slave_stop(i2c);
787
788 if (i2c_pxa_is_slavemode(i2c)) {
789 if (isr & ISR_ITE)
790 i2c_pxa_slave_txempty(i2c, isr);
791 if (isr & ISR_IRF)
792 i2c_pxa_slave_rxfull(i2c, isr);
793 } else if (i2c->msg) {
794 if (isr & ISR_ITE)
795 i2c_pxa_irq_txempty(i2c, isr);
796 if (isr & ISR_IRF)
797 i2c_pxa_irq_rxfull(i2c, isr);
798 } else {
799 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
800 }
801
802 return IRQ_HANDLED;
803 }
804
805
806 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
807 {
808 struct pxa_i2c *i2c = adap->algo_data;
809 int ret, i;
810
811 /* If the I2C controller is disabled we need to reset it (probably due
812 to a suspend/resume destroying state). We do this here as we can then
813 avoid worrying about resuming the controller before its users. */
814 if (!(readl(_ICR(i2c)) & ICR_IUE))
815 i2c_pxa_reset(i2c);
816
817 for (i = adap->retries; i >= 0; i--) {
818 ret = i2c_pxa_do_xfer(i2c, msgs, num);
819 if (ret != I2C_RETRY)
820 goto out;
821
822 if (i2c_debug)
823 dev_dbg(&adap->dev, "Retrying transmission\n");
824 udelay(100);
825 }
826 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
827 ret = -EREMOTEIO;
828 out:
829 i2c_pxa_set_slave(i2c, ret);
830 return ret;
831 }
832
833 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
834 {
835 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
836 }
837
838 static const struct i2c_algorithm i2c_pxa_algorithm = {
839 .master_xfer = i2c_pxa_xfer,
840 .functionality = i2c_pxa_functionality,
841 };
842
843 #define res_len(r) ((r)->end - (r)->start + 1)
844 static int i2c_pxa_probe(struct platform_device *dev)
845 {
846 struct pxa_i2c *i2c;
847 struct resource *res;
848 struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
849 int ret;
850 int irq;
851
852 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
853 irq = platform_get_irq(dev, 0);
854 if (res == NULL || irq < 0)
855 return -ENODEV;
856
857 if (!request_mem_region(res->start, res_len(res), res->name))
858 return -ENOMEM;
859
860 i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
861 if (!i2c) {
862 ret = -ENOMEM;
863 goto emalloc;
864 }
865
866 i2c->adap.owner = THIS_MODULE;
867 i2c->adap.algo = &i2c_pxa_algorithm;
868 i2c->adap.retries = 5;
869
870 spin_lock_init(&i2c->lock);
871 init_waitqueue_head(&i2c->wait);
872
873 sprintf(i2c->adap.name, "pxa_i2c-i2c.%u", dev->id);
874
875 i2c->clk = clk_get(&dev->dev, "I2CCLK");
876 if (IS_ERR(i2c->clk)) {
877 ret = PTR_ERR(i2c->clk);
878 goto eclk;
879 }
880
881 i2c->reg_base = ioremap(res->start, res_len(res));
882 if (!i2c->reg_base) {
883 ret = -EIO;
884 goto eremap;
885 }
886
887 i2c->iobase = res->start;
888 i2c->iosize = res_len(res);
889
890 i2c->irq = irq;
891
892 i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
893
894 #ifdef CONFIG_I2C_PXA_SLAVE
895 if (plat) {
896 i2c->slave_addr = plat->slave_addr;
897 i2c->slave = plat->slave;
898 }
899 #endif
900
901 clk_enable(i2c->clk);
902 #ifdef CONFIG_PXA27x
903 switch (dev->id) {
904 case 0:
905 pxa_gpio_mode(GPIO117_I2CSCL_MD);
906 pxa_gpio_mode(GPIO118_I2CSDA_MD);
907 break;
908 case 1:
909 local_irq_disable();
910 PCFR |= PCFR_PI2CEN;
911 local_irq_enable();
912 }
913 #endif
914
915 ret = request_irq(irq, i2c_pxa_handler, IRQF_DISABLED,
916 i2c->adap.name, i2c);
917 if (ret)
918 goto ereqirq;
919
920
921 i2c_pxa_reset(i2c);
922
923 i2c->adap.algo_data = i2c;
924 i2c->adap.dev.parent = &dev->dev;
925
926 if (plat) {
927 i2c->adap.class = plat->class;
928 }
929
930 /*
931 * If "dev->id" is negative we consider it as zero.
932 * The reason to do so is to avoid sysfs names that only make
933 * sense when there are multiple adapters.
934 */
935 i2c->adap.nr = dev->id != -1 ? dev->id : 0;
936
937 ret = i2c_add_numbered_adapter(&i2c->adap);
938 if (ret < 0) {
939 printk(KERN_INFO "I2C: Failed to add bus\n");
940 goto eadapt;
941 }
942
943 platform_set_drvdata(dev, i2c);
944
945 #ifdef CONFIG_I2C_PXA_SLAVE
946 printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
947 i2c->adap.dev.bus_id, i2c->slave_addr);
948 #else
949 printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
950 i2c->adap.dev.bus_id);
951 #endif
952 return 0;
953
954 eadapt:
955 free_irq(irq, i2c);
956 ereqirq:
957 clk_disable(i2c->clk);
958
959 #ifdef CONFIG_PXA27x
960 if (dev->id == 1) {
961 local_irq_disable();
962 PCFR &= ~PCFR_PI2CEN;
963 local_irq_enable();
964 }
965 #endif
966 eremap:
967 clk_put(i2c->clk);
968 eclk:
969 kfree(i2c);
970 emalloc:
971 release_mem_region(res->start, res_len(res));
972 return ret;
973 }
974
975 static int i2c_pxa_remove(struct platform_device *dev)
976 {
977 struct pxa_i2c *i2c = platform_get_drvdata(dev);
978
979 platform_set_drvdata(dev, NULL);
980
981 i2c_del_adapter(&i2c->adap);
982 free_irq(i2c->irq, i2c);
983
984 clk_disable(i2c->clk);
985 clk_put(i2c->clk);
986
987 #ifdef CONFIG_PXA27x
988 if (dev->id == 1) {
989 local_irq_disable();
990 PCFR &= ~PCFR_PI2CEN;
991 local_irq_enable();
992 }
993 #endif
994
995 release_mem_region(i2c->iobase, i2c->iosize);
996 kfree(i2c);
997
998 return 0;
999 }
1000
1001 static struct platform_driver i2c_pxa_driver = {
1002 .probe = i2c_pxa_probe,
1003 .remove = i2c_pxa_remove,
1004 .driver = {
1005 .name = "pxa2xx-i2c",
1006 },
1007 };
1008
1009 static int __init i2c_adap_pxa_init(void)
1010 {
1011 return platform_driver_register(&i2c_pxa_driver);
1012 }
1013
1014 static void i2c_adap_pxa_exit(void)
1015 {
1016 return platform_driver_unregister(&i2c_pxa_driver);
1017 }
1018
1019 MODULE_LICENSE("GPL");
1020
1021 module_init(i2c_adap_pxa_init);
1022 module_exit(i2c_adap_pxa_exit);
Linux kernel - Deliverables
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