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Linux 3.3-rc6
[linux/fpc-iii.git] / drivers / i2c / busses / i2c-pxa.c
blobd60364650990746897669725ac5b2324c7cb1d04
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 separated 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/init.h>
26 #include <linux/time.h>
27 #include <linux/sched.h>
28 #include <linux/delay.h>
29 #include <linux/errno.h>
30 #include <linux/interrupt.h>
31 #include <linux/i2c-pxa.h>
32 #include <linux/of_i2c.h>
33 #include <linux/platform_device.h>
34 #include <linux/err.h>
35 #include <linux/clk.h>
36 #include <linux/slab.h>
37 #include <linux/io.h>
38 #include <linux/i2c/pxa-i2c.h>
39
40 #include <asm/irq.h>
41
42 #ifndef CONFIG_HAVE_CLK
43 #define clk_get(dev, id) NULL
44 #define clk_put(clk) do { } while (0)
45 #define clk_disable(clk) do { } while (0)
46 #define clk_enable(clk) do { } while (0)
47 #endif
48
49 struct pxa_reg_layout {
50 u32 ibmr;
51 u32 idbr;
52 u32 icr;
53 u32 isr;
54 u32 isar;
55 };
56
57 enum pxa_i2c_types {
58 REGS_PXA2XX,
59 REGS_PXA3XX,
60 REGS_CE4100,
61 };
62
63 /*
64 * I2C registers definitions
65 */
66 static struct pxa_reg_layout pxa_reg_layout[] = {
67 [REGS_PXA2XX] = {
68 .ibmr = 0x00,
69 .idbr = 0x08,
70 .icr = 0x10,
71 .isr = 0x18,
72 .isar = 0x20,
73 },
74 [REGS_PXA3XX] = {
75 .ibmr = 0x00,
76 .idbr = 0x04,
77 .icr = 0x08,
78 .isr = 0x0c,
79 .isar = 0x10,
80 },
81 [REGS_CE4100] = {
82 .ibmr = 0x14,
83 .idbr = 0x0c,
84 .icr = 0x00,
85 .isr = 0x04,
86 /* no isar register */
87 },
88 };
89
90 static const struct platform_device_id i2c_pxa_id_table[] = {
91 { "pxa2xx-i2c", REGS_PXA2XX },
92 { "pxa3xx-pwri2c", REGS_PXA3XX },
93 { "ce4100-i2c", REGS_CE4100 },
94 { },
95 };
96 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
97
98 /*
99 * I2C bit definitions
100 */
101
102 #define ICR_START (1 << 0) /* start bit */
103 #define ICR_STOP (1 << 1) /* stop bit */
104 #define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
105 #define ICR_TB (1 << 3) /* transfer byte bit */
106 #define ICR_MA (1 << 4) /* master abort */
107 #define ICR_SCLE (1 << 5) /* master clock enable */
108 #define ICR_IUE (1 << 6) /* unit enable */
109 #define ICR_GCD (1 << 7) /* general call disable */
110 #define ICR_ITEIE (1 << 8) /* enable tx interrupts */
111 #define ICR_IRFIE (1 << 9) /* enable rx interrupts */
112 #define ICR_BEIE (1 << 10) /* enable bus error ints */
113 #define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
114 #define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
115 #define ICR_SADIE (1 << 13) /* slave address detected int enable */
116 #define ICR_UR (1 << 14) /* unit reset */
117 #define ICR_FM (1 << 15) /* fast mode */
118
119 #define ISR_RWM (1 << 0) /* read/write mode */
120 #define ISR_ACKNAK (1 << 1) /* ack/nak status */
121 #define ISR_UB (1 << 2) /* unit busy */
122 #define ISR_IBB (1 << 3) /* bus busy */
123 #define ISR_SSD (1 << 4) /* slave stop detected */
124 #define ISR_ALD (1 << 5) /* arbitration loss detected */
125 #define ISR_ITE (1 << 6) /* tx buffer empty */
126 #define ISR_IRF (1 << 7) /* rx buffer full */
127 #define ISR_GCAD (1 << 8) /* general call address detected */
128 #define ISR_SAD (1 << 9) /* slave address detected */
129 #define ISR_BED (1 << 10) /* bus error no ACK/NAK */
130
131 struct pxa_i2c {
132 spinlock_t lock;
133 wait_queue_head_t wait;
134 struct i2c_msg *msg;
135 unsigned int msg_num;
136 unsigned int msg_idx;
137 unsigned int msg_ptr;
138 unsigned int slave_addr;
139
140 struct i2c_adapter adap;
141 struct clk *clk;
142 #ifdef CONFIG_I2C_PXA_SLAVE
143 struct i2c_slave_client *slave;
144 #endif
145
146 unsigned int irqlogidx;
147 u32 isrlog[32];
148 u32 icrlog[32];
149
150 void __iomem *reg_base;
151 void __iomem *reg_ibmr;
152 void __iomem *reg_idbr;
153 void __iomem *reg_icr;
154 void __iomem *reg_isr;
155 void __iomem *reg_isar;
156
157 unsigned long iobase;
158 unsigned long iosize;
159
160 int irq;
161 unsigned int use_pio :1;
162 unsigned int fast_mode :1;
163 };
164
165 #define _IBMR(i2c) ((i2c)->reg_ibmr)
166 #define _IDBR(i2c) ((i2c)->reg_idbr)
167 #define _ICR(i2c) ((i2c)->reg_icr)
168 #define _ISR(i2c) ((i2c)->reg_isr)
169 #define _ISAR(i2c) ((i2c)->reg_isar)
170
171 /*
172 * I2C Slave mode address
173 */
174 #define I2C_PXA_SLAVE_ADDR 0x1
175
176 #ifdef DEBUG
177
178 struct bits {
179 u32 mask;
180 const char *set;
181 const char *unset;
182 };
183 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
184
185 static inline void
186 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
187 {
188 printk("%s %08x: ", prefix, val);
189 while (num--) {
190 const char *str = val & bits->mask ? bits->set : bits->unset;
191 if (str)
192 printk("%s ", str);
193 bits++;
194 }
195 }
196
197 static const struct bits isr_bits[] = {
198 PXA_BIT(ISR_RWM, "RX", "TX"),
199 PXA_BIT(ISR_ACKNAK, "NAK", "ACK"),
200 PXA_BIT(ISR_UB, "Bsy", "Rdy"),
201 PXA_BIT(ISR_IBB, "BusBsy", "BusRdy"),
202 PXA_BIT(ISR_SSD, "SlaveStop", NULL),
203 PXA_BIT(ISR_ALD, "ALD", NULL),
204 PXA_BIT(ISR_ITE, "TxEmpty", NULL),
205 PXA_BIT(ISR_IRF, "RxFull", NULL),
206 PXA_BIT(ISR_GCAD, "GenCall", NULL),
207 PXA_BIT(ISR_SAD, "SlaveAddr", NULL),
208 PXA_BIT(ISR_BED, "BusErr", NULL),
209 };
210
211 static void decode_ISR(unsigned int val)
212 {
213 decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
214 printk("\n");
215 }
216
217 static const struct bits icr_bits[] = {
218 PXA_BIT(ICR_START, "START", NULL),
219 PXA_BIT(ICR_STOP, "STOP", NULL),
220 PXA_BIT(ICR_ACKNAK, "ACKNAK", NULL),
221 PXA_BIT(ICR_TB, "TB", NULL),
222 PXA_BIT(ICR_MA, "MA", NULL),
223 PXA_BIT(ICR_SCLE, "SCLE", "scle"),
224 PXA_BIT(ICR_IUE, "IUE", "iue"),
225 PXA_BIT(ICR_GCD, "GCD", NULL),
226 PXA_BIT(ICR_ITEIE, "ITEIE", NULL),
227 PXA_BIT(ICR_IRFIE, "IRFIE", NULL),
228 PXA_BIT(ICR_BEIE, "BEIE", NULL),
229 PXA_BIT(ICR_SSDIE, "SSDIE", NULL),
230 PXA_BIT(ICR_ALDIE, "ALDIE", NULL),
231 PXA_BIT(ICR_SADIE, "SADIE", NULL),
232 PXA_BIT(ICR_UR, "UR", "ur"),
233 };
234
235 #ifdef CONFIG_I2C_PXA_SLAVE
236 static void decode_ICR(unsigned int val)
237 {
238 decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
239 printk("\n");
240 }
241 #endif
242
243 static unsigned int i2c_debug = DEBUG;
244
245 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
246 {
247 dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
248 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
249 }
250
251 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
252
253 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
254 {
255 unsigned int i;
256 printk(KERN_ERR "i2c: error: %s\n", why);
257 printk(KERN_ERR "i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
258 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
259 printk(KERN_ERR "i2c: ICR: %08x ISR: %08x\n",
260 readl(_ICR(i2c)), readl(_ISR(i2c)));
261 printk(KERN_DEBUG "i2c: log: ");
262 for (i = 0; i < i2c->irqlogidx; i++)
263 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
264 printk("\n");
265 }
266
267 #else /* ifdef DEBUG */
268
269 #define i2c_debug 0
270
271 #define show_state(i2c) do { } while (0)
272 #define decode_ISR(val) do { } while (0)
273 #define decode_ICR(val) do { } while (0)
274 #define i2c_pxa_scream_blue_murder(i2c, why) do { } while (0)
275
276 #endif /* ifdef DEBUG / else */
277
278 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
279 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
280
281 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
282 {
283 return !(readl(_ICR(i2c)) & ICR_SCLE);
284 }
285
286 static void i2c_pxa_abort(struct pxa_i2c *i2c)
287 {
288 int i = 250;
289
290 if (i2c_pxa_is_slavemode(i2c)) {
291 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
292 return;
293 }
294
295 while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
296 unsigned long icr = readl(_ICR(i2c));
297
298 icr &= ~ICR_START;
299 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
300
301 writel(icr, _ICR(i2c));
302
303 show_state(i2c);
304
305 mdelay(1);
306 i --;
307 }
308
309 writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
310 _ICR(i2c));
311 }
312
313 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
314 {
315 int timeout = DEF_TIMEOUT;
316
317 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
318 if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
319 timeout += 4;
320
321 msleep(2);
322 show_state(i2c);
323 }
324
325 if (timeout < 0)
326 show_state(i2c);
327
328 return timeout < 0 ? I2C_RETRY : 0;
329 }
330
331 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
332 {
333 unsigned long timeout = jiffies + HZ*4;
334
335 while (time_before(jiffies, timeout)) {
336 if (i2c_debug > 1)
337 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
338 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
339
340 if (readl(_ISR(i2c)) & ISR_SAD) {
341 if (i2c_debug > 0)
342 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
343 goto out;
344 }
345
346 /* wait for unit and bus being not busy, and we also do a
347 * quick check of the i2c lines themselves to ensure they've
348 * gone high...
349 */
350 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
351 if (i2c_debug > 0)
352 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
353 return 1;
354 }
355
356 msleep(1);
357 }
358
359 if (i2c_debug > 0)
360 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
361 out:
362 return 0;
363 }
364
365 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
366 {
367 if (i2c_debug)
368 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
369
370 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
371 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
372 if (!i2c_pxa_wait_master(i2c)) {
373 dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
374 return I2C_RETRY;
375 }
376 }
377
378 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
379 return 0;
380 }
381
382 #ifdef CONFIG_I2C_PXA_SLAVE
383 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
384 {
385 unsigned long timeout = jiffies + HZ*1;
386
387 /* wait for stop */
388
389 show_state(i2c);
390
391 while (time_before(jiffies, timeout)) {
392 if (i2c_debug > 1)
393 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
394 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
395
396 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
397 (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
398 (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
399 if (i2c_debug > 1)
400 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
401 return 1;
402 }
403
404 msleep(1);
405 }
406
407 if (i2c_debug > 0)
408 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
409 return 0;
410 }
411
412 /*
413 * clear the hold on the bus, and take of anything else
414 * that has been configured
415 */
416 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
417 {
418 show_state(i2c);
419
420 if (errcode < 0) {
421 udelay(100); /* simple delay */
422 } else {
423 /* we need to wait for the stop condition to end */
424
425 /* if we where in stop, then clear... */
426 if (readl(_ICR(i2c)) & ICR_STOP) {
427 udelay(100);
428 writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
429 }
430
431 if (!i2c_pxa_wait_slave(i2c)) {
432 dev_err(&i2c->adap.dev, "%s: wait timedout\n",
433 __func__);
434 return;
435 }
436 }
437
438 writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
439 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
440
441 if (i2c_debug) {
442 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
443 decode_ICR(readl(_ICR(i2c)));
444 }
445 }
446 #else
447 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
448 #endif
449
450 static void i2c_pxa_reset(struct pxa_i2c *i2c)
451 {
452 pr_debug("Resetting I2C Controller Unit\n");
453
454 /* abort any transfer currently under way */
455 i2c_pxa_abort(i2c);
456
457 /* reset according to 9.8 */
458 writel(ICR_UR, _ICR(i2c));
459 writel(I2C_ISR_INIT, _ISR(i2c));
460 writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
461
462 if (i2c->reg_isar)
463 writel(i2c->slave_addr, _ISAR(i2c));
464
465 /* set control register values */
466 writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
467
468 #ifdef CONFIG_I2C_PXA_SLAVE
469 dev_info(&i2c->adap.dev, "Enabling slave mode\n");
470 writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
471 #endif
472
473 i2c_pxa_set_slave(i2c, 0);
474
475 /* enable unit */
476 writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
477 udelay(100);
478 }
479
480
481 #ifdef CONFIG_I2C_PXA_SLAVE
482 /*
483 * PXA I2C Slave mode
484 */
485
486 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
487 {
488 if (isr & ISR_BED) {
489 /* what should we do here? */
490 } else {
491 int ret = 0;
492
493 if (i2c->slave != NULL)
494 ret = i2c->slave->read(i2c->slave->data);
495
496 writel(ret, _IDBR(i2c));
497 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */
498 }
499 }
500
501 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
502 {
503 unsigned int byte = readl(_IDBR(i2c));
504
505 if (i2c->slave != NULL)
506 i2c->slave->write(i2c->slave->data, byte);
507
508 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
509 }
510
511 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
512 {
513 int timeout;
514
515 if (i2c_debug > 0)
516 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
517 (isr & ISR_RWM) ? 'r' : 't');
518
519 if (i2c->slave != NULL)
520 i2c->slave->event(i2c->slave->data,
521 (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
522
523 /*
524 * slave could interrupt in the middle of us generating a
525 * start condition... if this happens, we'd better back off
526 * and stop holding the poor thing up
527 */
528 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
529 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
530
531 timeout = 0x10000;
532
533 while (1) {
534 if ((readl(_IBMR(i2c)) & 2) == 2)
535 break;
536
537 timeout--;
538
539 if (timeout <= 0) {
540 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
541 break;
542 }
543 }
544
545 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
546 }
547
548 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
549 {
550 if (i2c_debug > 2)
551 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
552
553 if (i2c->slave != NULL)
554 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
555
556 if (i2c_debug > 2)
557 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
558
559 /*
560 * If we have a master-mode message waiting,
561 * kick it off now that the slave has completed.
562 */
563 if (i2c->msg)
564 i2c_pxa_master_complete(i2c, I2C_RETRY);
565 }
566 #else
567 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
568 {
569 if (isr & ISR_BED) {
570 /* what should we do here? */
571 } else {
572 writel(0, _IDBR(i2c));
573 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
574 }
575 }
576
577 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
578 {
579 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
580 }
581
582 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
583 {
584 int timeout;
585
586 /*
587 * slave could interrupt in the middle of us generating a
588 * start condition... if this happens, we'd better back off
589 * and stop holding the poor thing up
590 */
591 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
592 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
593
594 timeout = 0x10000;
595
596 while (1) {
597 if ((readl(_IBMR(i2c)) & 2) == 2)
598 break;
599
600 timeout--;
601
602 if (timeout <= 0) {
603 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
604 break;
605 }
606 }
607
608 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
609 }
610
611 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
612 {
613 if (i2c->msg)
614 i2c_pxa_master_complete(i2c, I2C_RETRY);
615 }
616 #endif
617
618 /*
619 * PXA I2C Master mode
620 */
621
622 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
623 {
624 unsigned int addr = (msg->addr & 0x7f) << 1;
625
626 if (msg->flags & I2C_M_RD)
627 addr |= 1;
628
629 return addr;
630 }
631
632 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
633 {
634 u32 icr;
635
636 /*
637 * Step 1: target slave address into IDBR
638 */
639 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
640
641 /*
642 * Step 2: initiate the write.
643 */
644 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
645 writel(icr | ICR_START | ICR_TB, _ICR(i2c));
646 }
647
648 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
649 {
650 u32 icr;
651
652 /*
653 * Clear the STOP and ACK flags
654 */
655 icr = readl(_ICR(i2c));
656 icr &= ~(ICR_STOP | ICR_ACKNAK);
657 writel(icr, _ICR(i2c));
658 }
659
660 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
661 {
662 /* make timeout the same as for interrupt based functions */
663 long timeout = 2 * DEF_TIMEOUT;
664
665 /*
666 * Wait for the bus to become free.
667 */
668 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
669 udelay(1000);
670 show_state(i2c);
671 }
672
673 if (timeout < 0) {
674 show_state(i2c);
675 dev_err(&i2c->adap.dev,
676 "i2c_pxa: timeout waiting for bus free\n");
677 return I2C_RETRY;
678 }
679
680 /*
681 * Set master mode.
682 */
683 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
684
685 return 0;
686 }
687
688 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
689 struct i2c_msg *msg, int num)
690 {
691 unsigned long timeout = 500000; /* 5 seconds */
692 int ret = 0;
693
694 ret = i2c_pxa_pio_set_master(i2c);
695 if (ret)
696 goto out;
697
698 i2c->msg = msg;
699 i2c->msg_num = num;
700 i2c->msg_idx = 0;
701 i2c->msg_ptr = 0;
702 i2c->irqlogidx = 0;
703
704 i2c_pxa_start_message(i2c);
705
706 while (i2c->msg_num > 0 && --timeout) {
707 i2c_pxa_handler(0, i2c);
708 udelay(10);
709 }
710
711 i2c_pxa_stop_message(i2c);
712
713 /*
714 * We place the return code in i2c->msg_idx.
715 */
716 ret = i2c->msg_idx;
717
718 out:
719 if (timeout == 0)
720 i2c_pxa_scream_blue_murder(i2c, "timeout");
721
722 return ret;
723 }
724
725 /*
726 * We are protected by the adapter bus mutex.
727 */
728 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
729 {
730 long timeout;
731 int ret;
732
733 /*
734 * Wait for the bus to become free.
735 */
736 ret = i2c_pxa_wait_bus_not_busy(i2c);
737 if (ret) {
738 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
739 goto out;
740 }
741
742 /*
743 * Set master mode.
744 */
745 ret = i2c_pxa_set_master(i2c);
746 if (ret) {
747 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
748 goto out;
749 }
750
751 spin_lock_irq(&i2c->lock);
752
753 i2c->msg = msg;
754 i2c->msg_num = num;
755 i2c->msg_idx = 0;
756 i2c->msg_ptr = 0;
757 i2c->irqlogidx = 0;
758
759 i2c_pxa_start_message(i2c);
760
761 spin_unlock_irq(&i2c->lock);
762
763 /*
764 * The rest of the processing occurs in the interrupt handler.
765 */
766 timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
767 i2c_pxa_stop_message(i2c);
768
769 /*
770 * We place the return code in i2c->msg_idx.
771 */
772 ret = i2c->msg_idx;
773
774 if (!timeout && i2c->msg_num) {
775 i2c_pxa_scream_blue_murder(i2c, "timeout");
776 ret = I2C_RETRY;
777 }
778
779 out:
780 return ret;
781 }
782
783 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
784 struct i2c_msg msgs[], int num)
785 {
786 struct pxa_i2c *i2c = adap->algo_data;
787 int ret, i;
788
789 /* If the I2C controller is disabled we need to reset it
790 (probably due to a suspend/resume destroying state). We do
791 this here as we can then avoid worrying about resuming the
792 controller before its users. */
793 if (!(readl(_ICR(i2c)) & ICR_IUE))
794 i2c_pxa_reset(i2c);
795
796 for (i = adap->retries; i >= 0; i--) {
797 ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
798 if (ret != I2C_RETRY)
799 goto out;
800
801 if (i2c_debug)
802 dev_dbg(&adap->dev, "Retrying transmission\n");
803 udelay(100);
804 }
805 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
806 ret = -EREMOTEIO;
807 out:
808 i2c_pxa_set_slave(i2c, ret);
809 return ret;
810 }
811
812 /*
813 * i2c_pxa_master_complete - complete the message and wake up.
814 */
815 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
816 {
817 i2c->msg_ptr = 0;
818 i2c->msg = NULL;
819 i2c->msg_idx ++;
820 i2c->msg_num = 0;
821 if (ret)
822 i2c->msg_idx = ret;
823 if (!i2c->use_pio)
824 wake_up(&i2c->wait);
825 }
826
827 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
828 {
829 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
830
831 again:
832 /*
833 * If ISR_ALD is set, we lost arbitration.
834 */
835 if (isr & ISR_ALD) {
836 /*
837 * Do we need to do anything here? The PXA docs
838 * are vague about what happens.
839 */
840 i2c_pxa_scream_blue_murder(i2c, "ALD set");
841
842 /*
843 * We ignore this error. We seem to see spurious ALDs
844 * for seemingly no reason. If we handle them as I think
845 * they should, we end up causing an I2C error, which
846 * is painful for some systems.
847 */
848 return; /* ignore */
849 }
850
851 if (isr & ISR_BED) {
852 int ret = BUS_ERROR;
853
854 /*
855 * I2C bus error - either the device NAK'd us, or
856 * something more serious happened. If we were NAK'd
857 * on the initial address phase, we can retry.
858 */
859 if (isr & ISR_ACKNAK) {
860 if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
861 ret = I2C_RETRY;
862 else
863 ret = XFER_NAKED;
864 }
865 i2c_pxa_master_complete(i2c, ret);
866 } else if (isr & ISR_RWM) {
867 /*
868 * Read mode. We have just sent the address byte, and
869 * now we must initiate the transfer.
870 */
871 if (i2c->msg_ptr == i2c->msg->len - 1 &&
872 i2c->msg_idx == i2c->msg_num - 1)
873 icr |= ICR_STOP | ICR_ACKNAK;
874
875 icr |= ICR_ALDIE | ICR_TB;
876 } else if (i2c->msg_ptr < i2c->msg->len) {
877 /*
878 * Write mode. Write the next data byte.
879 */
880 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
881
882 icr |= ICR_ALDIE | ICR_TB;
883
884 /*
885 * If this is the last byte of the last message, send
886 * a STOP.
887 */
888 if (i2c->msg_ptr == i2c->msg->len &&
889 i2c->msg_idx == i2c->msg_num - 1)
890 icr |= ICR_STOP;
891 } else if (i2c->msg_idx < i2c->msg_num - 1) {
892 /*
893 * Next segment of the message.
894 */
895 i2c->msg_ptr = 0;
896 i2c->msg_idx ++;
897 i2c->msg++;
898
899 /*
900 * If we aren't doing a repeated start and address,
901 * go back and try to send the next byte. Note that
902 * we do not support switching the R/W direction here.
903 */
904 if (i2c->msg->flags & I2C_M_NOSTART)
905 goto again;
906
907 /*
908 * Write the next address.
909 */
910 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
911
912 /*
913 * And trigger a repeated start, and send the byte.
914 */
915 icr &= ~ICR_ALDIE;
916 icr |= ICR_START | ICR_TB;
917 } else {
918 if (i2c->msg->len == 0) {
919 /*
920 * Device probes have a message length of zero
921 * and need the bus to be reset before it can
922 * be used again.
923 */
924 i2c_pxa_reset(i2c);
925 }
926 i2c_pxa_master_complete(i2c, 0);
927 }
928
929 i2c->icrlog[i2c->irqlogidx-1] = icr;
930
931 writel(icr, _ICR(i2c));
932 show_state(i2c);
933 }
934
935 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
936 {
937 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
938
939 /*
940 * Read the byte.
941 */
942 i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
943
944 if (i2c->msg_ptr < i2c->msg->len) {
945 /*
946 * If this is the last byte of the last
947 * message, send a STOP.
948 */
949 if (i2c->msg_ptr == i2c->msg->len - 1)
950 icr |= ICR_STOP | ICR_ACKNAK;
951
952 icr |= ICR_ALDIE | ICR_TB;
953 } else {
954 i2c_pxa_master_complete(i2c, 0);
955 }
956
957 i2c->icrlog[i2c->irqlogidx-1] = icr;
958
959 writel(icr, _ICR(i2c));
960 }
961
962 #define VALID_INT_SOURCE (ISR_SSD | ISR_ALD | ISR_ITE | ISR_IRF | \
963 ISR_SAD | ISR_BED)
964 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
965 {
966 struct pxa_i2c *i2c = dev_id;
967 u32 isr = readl(_ISR(i2c));
968
969 if (!(isr & VALID_INT_SOURCE))
970 return IRQ_NONE;
971
972 if (i2c_debug > 2 && 0) {
973 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
974 __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
975 decode_ISR(isr);
976 }
977
978 if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
979 i2c->isrlog[i2c->irqlogidx++] = isr;
980
981 show_state(i2c);
982
983 /*
984 * Always clear all pending IRQs.
985 */
986 writel(isr & VALID_INT_SOURCE, _ISR(i2c));
987
988 if (isr & ISR_SAD)
989 i2c_pxa_slave_start(i2c, isr);
990 if (isr & ISR_SSD)
991 i2c_pxa_slave_stop(i2c);
992
993 if (i2c_pxa_is_slavemode(i2c)) {
994 if (isr & ISR_ITE)
995 i2c_pxa_slave_txempty(i2c, isr);
996 if (isr & ISR_IRF)
997 i2c_pxa_slave_rxfull(i2c, isr);
998 } else if (i2c->msg) {
999 if (isr & ISR_ITE)
1000 i2c_pxa_irq_txempty(i2c, isr);
1001 if (isr & ISR_IRF)
1002 i2c_pxa_irq_rxfull(i2c, isr);
1003 } else {
1004 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
1005 }
1006
1007 return IRQ_HANDLED;
1008 }
1009
1010
1011 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
1012 {
1013 struct pxa_i2c *i2c = adap->algo_data;
1014 int ret, i;
1015
1016 for (i = adap->retries; i >= 0; i--) {
1017 ret = i2c_pxa_do_xfer(i2c, msgs, num);
1018 if (ret != I2C_RETRY)
1019 goto out;
1020
1021 if (i2c_debug)
1022 dev_dbg(&adap->dev, "Retrying transmission\n");
1023 udelay(100);
1024 }
1025 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
1026 ret = -EREMOTEIO;
1027 out:
1028 i2c_pxa_set_slave(i2c, ret);
1029 return ret;
1030 }
1031
1032 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
1033 {
1034 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
1035 }
1036
1037 static const struct i2c_algorithm i2c_pxa_algorithm = {
1038 .master_xfer = i2c_pxa_xfer,
1039 .functionality = i2c_pxa_functionality,
1040 };
1041
1042 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
1043 .master_xfer = i2c_pxa_pio_xfer,
1044 .functionality = i2c_pxa_functionality,
1045 };
1046
1047 static int i2c_pxa_probe(struct platform_device *dev)
1048 {
1049 struct pxa_i2c *i2c;
1050 struct resource *res;
1051 struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
1052 const struct platform_device_id *id = platform_get_device_id(dev);
1053 enum pxa_i2c_types i2c_type = id->driver_data;
1054 int ret;
1055 int irq;
1056
1057 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
1058 irq = platform_get_irq(dev, 0);
1059 if (res == NULL || irq < 0)
1060 return -ENODEV;
1061
1062 if (!request_mem_region(res->start, resource_size(res), res->name))
1063 return -ENOMEM;
1064
1065 i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
1066 if (!i2c) {
1067 ret = -ENOMEM;
1068 goto emalloc;
1069 }
1070
1071 i2c->adap.owner = THIS_MODULE;
1072 i2c->adap.retries = 5;
1073
1074 spin_lock_init(&i2c->lock);
1075 init_waitqueue_head(&i2c->wait);
1076
1077 /*
1078 * If "dev->id" is negative we consider it as zero.
1079 * The reason to do so is to avoid sysfs names that only make
1080 * sense when there are multiple adapters.
1081 */
1082 i2c->adap.nr = dev->id;
1083 snprintf(i2c->adap.name, sizeof(i2c->adap.name), "pxa_i2c-i2c.%u",
1084 i2c->adap.nr);
1085
1086 i2c->clk = clk_get(&dev->dev, NULL);
1087 if (IS_ERR(i2c->clk)) {
1088 ret = PTR_ERR(i2c->clk);
1089 goto eclk;
1090 }
1091
1092 i2c->reg_base = ioremap(res->start, resource_size(res));
1093 if (!i2c->reg_base) {
1094 ret = -EIO;
1095 goto eremap;
1096 }
1097
1098 i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
1099 i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr;
1100 i2c->reg_icr = i2c->reg_base + pxa_reg_layout[i2c_type].icr;
1101 i2c->reg_isr = i2c->reg_base + pxa_reg_layout[i2c_type].isr;
1102 if (i2c_type != REGS_CE4100)
1103 i2c->reg_isar = i2c->reg_base + pxa_reg_layout[i2c_type].isar;
1104
1105 i2c->iobase = res->start;
1106 i2c->iosize = resource_size(res);
1107
1108 i2c->irq = irq;
1109
1110 i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1111
1112 #ifdef CONFIG_I2C_PXA_SLAVE
1113 if (plat) {
1114 i2c->slave_addr = plat->slave_addr;
1115 i2c->slave = plat->slave;
1116 }
1117 #endif
1118
1119 clk_enable(i2c->clk);
1120
1121 if (plat) {
1122 i2c->adap.class = plat->class;
1123 i2c->use_pio = plat->use_pio;
1124 i2c->fast_mode = plat->fast_mode;
1125 }
1126
1127 if (i2c->use_pio) {
1128 i2c->adap.algo = &i2c_pxa_pio_algorithm;
1129 } else {
1130 i2c->adap.algo = &i2c_pxa_algorithm;
1131 ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
1132 i2c->adap.name, i2c);
1133 if (ret)
1134 goto ereqirq;
1135 }
1136
1137 i2c_pxa_reset(i2c);
1138
1139 i2c->adap.algo_data = i2c;
1140 i2c->adap.dev.parent = &dev->dev;
1141 #ifdef CONFIG_OF
1142 i2c->adap.dev.of_node = dev->dev.of_node;
1143 #endif
1144
1145 ret = i2c_add_numbered_adapter(&i2c->adap);
1146 if (ret < 0) {
1147 printk(KERN_INFO "I2C: Failed to add bus\n");
1148 goto eadapt;
1149 }
1150 of_i2c_register_devices(&i2c->adap);
1151
1152 platform_set_drvdata(dev, i2c);
1153
1154 #ifdef CONFIG_I2C_PXA_SLAVE
1155 printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
1156 dev_name(&i2c->adap.dev), i2c->slave_addr);
1157 #else
1158 printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
1159 dev_name(&i2c->adap.dev));
1160 #endif
1161 return 0;
1162
1163 eadapt:
1164 if (!i2c->use_pio)
1165 free_irq(irq, i2c);
1166 ereqirq:
1167 clk_disable(i2c->clk);
1168 iounmap(i2c->reg_base);
1169 eremap:
1170 clk_put(i2c->clk);
1171 eclk:
1172 kfree(i2c);
1173 emalloc:
1174 release_mem_region(res->start, resource_size(res));
1175 return ret;
1176 }
1177
1178 static int __exit i2c_pxa_remove(struct platform_device *dev)
1179 {
1180 struct pxa_i2c *i2c = platform_get_drvdata(dev);
1181
1182 platform_set_drvdata(dev, NULL);
1183
1184 i2c_del_adapter(&i2c->adap);
1185 if (!i2c->use_pio)
1186 free_irq(i2c->irq, i2c);
1187
1188 clk_disable(i2c->clk);
1189 clk_put(i2c->clk);
1190
1191 iounmap(i2c->reg_base);
1192 release_mem_region(i2c->iobase, i2c->iosize);
1193 kfree(i2c);
1194
1195 return 0;
1196 }
1197
1198 #ifdef CONFIG_PM
1199 static int i2c_pxa_suspend_noirq(struct device *dev)
1200 {
1201 struct platform_device *pdev = to_platform_device(dev);
1202 struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1203
1204 clk_disable(i2c->clk);
1205
1206 return 0;
1207 }
1208
1209 static int i2c_pxa_resume_noirq(struct device *dev)
1210 {
1211 struct platform_device *pdev = to_platform_device(dev);
1212 struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1213
1214 clk_enable(i2c->clk);
1215 i2c_pxa_reset(i2c);
1216
1217 return 0;
1218 }
1219
1220 static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
1221 .suspend_noirq = i2c_pxa_suspend_noirq,
1222 .resume_noirq = i2c_pxa_resume_noirq,
1223 };
1224
1225 #define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
1226 #else
1227 #define I2C_PXA_DEV_PM_OPS NULL
1228 #endif
1229
1230 static struct platform_driver i2c_pxa_driver = {
1231 .probe = i2c_pxa_probe,
1232 .remove = __exit_p(i2c_pxa_remove),
1233 .driver = {
1234 .name = "pxa2xx-i2c",
1235 .owner = THIS_MODULE,
1236 .pm = I2C_PXA_DEV_PM_OPS,
1237 },
1238 .id_table = i2c_pxa_id_table,
1239 };
1240
1241 static int __init i2c_adap_pxa_init(void)
1242 {
1243 return platform_driver_register(&i2c_pxa_driver);
1244 }
1245
1246 static void __exit i2c_adap_pxa_exit(void)
1247 {
1248 platform_driver_unregister(&i2c_pxa_driver);
1249 }
1250
1251 MODULE_LICENSE("GPL");
1252 MODULE_ALIAS("platform:pxa2xx-i2c");
1253
1254 subsys_initcall(i2c_adap_pxa_init);
1255 module_exit(i2c_adap_pxa_exit);
Linux with added FPC-III support