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[mirror_ubuntu-bionic-kernel.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 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.h>
33 #include <linux/of_device.h>
34 #include <linux/of_i2c.h>
35 #include <linux/platform_device.h>
36 #include <linux/err.h>
37 #include <linux/clk.h>
38 #include <linux/slab.h>
39 #include <linux/io.h>
40 #include <linux/i2c/pxa-i2c.h>
41
42 #include <asm/irq.h>
43
44 struct pxa_reg_layout {
45 u32 ibmr;
46 u32 idbr;
47 u32 icr;
48 u32 isr;
49 u32 isar;
50 };
51
52 enum pxa_i2c_types {
53 REGS_PXA2XX,
54 REGS_PXA3XX,
55 REGS_CE4100,
56 };
57
58 /*
59 * I2C registers definitions
60 */
61 static struct pxa_reg_layout pxa_reg_layout[] = {
62 [REGS_PXA2XX] = {
63 .ibmr = 0x00,
64 .idbr = 0x08,
65 .icr = 0x10,
66 .isr = 0x18,
67 .isar = 0x20,
68 },
69 [REGS_PXA3XX] = {
70 .ibmr = 0x00,
71 .idbr = 0x04,
72 .icr = 0x08,
73 .isr = 0x0c,
74 .isar = 0x10,
75 },
76 [REGS_CE4100] = {
77 .ibmr = 0x14,
78 .idbr = 0x0c,
79 .icr = 0x00,
80 .isr = 0x04,
81 /* no isar register */
82 },
83 };
84
85 static const struct platform_device_id i2c_pxa_id_table[] = {
86 { "pxa2xx-i2c", REGS_PXA2XX },
87 { "pxa3xx-pwri2c", REGS_PXA3XX },
88 { "ce4100-i2c", REGS_CE4100 },
89 { },
90 };
91 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
92
93 /*
94 * I2C bit definitions
95 */
96
97 #define ICR_START (1 << 0) /* start bit */
98 #define ICR_STOP (1 << 1) /* stop bit */
99 #define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
100 #define ICR_TB (1 << 3) /* transfer byte bit */
101 #define ICR_MA (1 << 4) /* master abort */
102 #define ICR_SCLE (1 << 5) /* master clock enable */
103 #define ICR_IUE (1 << 6) /* unit enable */
104 #define ICR_GCD (1 << 7) /* general call disable */
105 #define ICR_ITEIE (1 << 8) /* enable tx interrupts */
106 #define ICR_IRFIE (1 << 9) /* enable rx interrupts */
107 #define ICR_BEIE (1 << 10) /* enable bus error ints */
108 #define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
109 #define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
110 #define ICR_SADIE (1 << 13) /* slave address detected int enable */
111 #define ICR_UR (1 << 14) /* unit reset */
112 #define ICR_FM (1 << 15) /* fast mode */
113
114 #define ISR_RWM (1 << 0) /* read/write mode */
115 #define ISR_ACKNAK (1 << 1) /* ack/nak status */
116 #define ISR_UB (1 << 2) /* unit busy */
117 #define ISR_IBB (1 << 3) /* bus busy */
118 #define ISR_SSD (1 << 4) /* slave stop detected */
119 #define ISR_ALD (1 << 5) /* arbitration loss detected */
120 #define ISR_ITE (1 << 6) /* tx buffer empty */
121 #define ISR_IRF (1 << 7) /* rx buffer full */
122 #define ISR_GCAD (1 << 8) /* general call address detected */
123 #define ISR_SAD (1 << 9) /* slave address detected */
124 #define ISR_BED (1 << 10) /* bus error no ACK/NAK */
125
126 struct pxa_i2c {
127 spinlock_t lock;
128 wait_queue_head_t wait;
129 struct i2c_msg *msg;
130 unsigned int msg_num;
131 unsigned int msg_idx;
132 unsigned int msg_ptr;
133 unsigned int slave_addr;
134
135 struct i2c_adapter adap;
136 struct clk *clk;
137 #ifdef CONFIG_I2C_PXA_SLAVE
138 struct i2c_slave_client *slave;
139 #endif
140
141 unsigned int irqlogidx;
142 u32 isrlog[32];
143 u32 icrlog[32];
144
145 void __iomem *reg_base;
146 void __iomem *reg_ibmr;
147 void __iomem *reg_idbr;
148 void __iomem *reg_icr;
149 void __iomem *reg_isr;
150 void __iomem *reg_isar;
151
152 unsigned long iobase;
153 unsigned long iosize;
154
155 int irq;
156 unsigned int use_pio :1;
157 unsigned int fast_mode :1;
158 };
159
160 #define _IBMR(i2c) ((i2c)->reg_ibmr)
161 #define _IDBR(i2c) ((i2c)->reg_idbr)
162 #define _ICR(i2c) ((i2c)->reg_icr)
163 #define _ISR(i2c) ((i2c)->reg_isr)
164 #define _ISAR(i2c) ((i2c)->reg_isar)
165
166 /*
167 * I2C Slave mode address
168 */
169 #define I2C_PXA_SLAVE_ADDR 0x1
170
171 #ifdef DEBUG
172
173 struct bits {
174 u32 mask;
175 const char *set;
176 const char *unset;
177 };
178 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
179
180 static inline void
181 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
182 {
183 printk("%s %08x: ", prefix, val);
184 while (num--) {
185 const char *str = val & bits->mask ? bits->set : bits->unset;
186 if (str)
187 printk("%s ", str);
188 bits++;
189 }
190 }
191
192 static const struct bits isr_bits[] = {
193 PXA_BIT(ISR_RWM, "RX", "TX"),
194 PXA_BIT(ISR_ACKNAK, "NAK", "ACK"),
195 PXA_BIT(ISR_UB, "Bsy", "Rdy"),
196 PXA_BIT(ISR_IBB, "BusBsy", "BusRdy"),
197 PXA_BIT(ISR_SSD, "SlaveStop", NULL),
198 PXA_BIT(ISR_ALD, "ALD", NULL),
199 PXA_BIT(ISR_ITE, "TxEmpty", NULL),
200 PXA_BIT(ISR_IRF, "RxFull", NULL),
201 PXA_BIT(ISR_GCAD, "GenCall", NULL),
202 PXA_BIT(ISR_SAD, "SlaveAddr", NULL),
203 PXA_BIT(ISR_BED, "BusErr", NULL),
204 };
205
206 static void decode_ISR(unsigned int val)
207 {
208 decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
209 printk("\n");
210 }
211
212 static const struct bits icr_bits[] = {
213 PXA_BIT(ICR_START, "START", NULL),
214 PXA_BIT(ICR_STOP, "STOP", NULL),
215 PXA_BIT(ICR_ACKNAK, "ACKNAK", NULL),
216 PXA_BIT(ICR_TB, "TB", NULL),
217 PXA_BIT(ICR_MA, "MA", NULL),
218 PXA_BIT(ICR_SCLE, "SCLE", "scle"),
219 PXA_BIT(ICR_IUE, "IUE", "iue"),
220 PXA_BIT(ICR_GCD, "GCD", NULL),
221 PXA_BIT(ICR_ITEIE, "ITEIE", NULL),
222 PXA_BIT(ICR_IRFIE, "IRFIE", NULL),
223 PXA_BIT(ICR_BEIE, "BEIE", NULL),
224 PXA_BIT(ICR_SSDIE, "SSDIE", NULL),
225 PXA_BIT(ICR_ALDIE, "ALDIE", NULL),
226 PXA_BIT(ICR_SADIE, "SADIE", NULL),
227 PXA_BIT(ICR_UR, "UR", "ur"),
228 };
229
230 #ifdef CONFIG_I2C_PXA_SLAVE
231 static void decode_ICR(unsigned int val)
232 {
233 decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
234 printk("\n");
235 }
236 #endif
237
238 static unsigned int i2c_debug = DEBUG;
239
240 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
241 {
242 dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
243 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
244 }
245
246 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
247
248 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
249 {
250 unsigned int i;
251 printk(KERN_ERR "i2c: error: %s\n", why);
252 printk(KERN_ERR "i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
253 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
254 printk(KERN_ERR "i2c: ICR: %08x ISR: %08x\n",
255 readl(_ICR(i2c)), readl(_ISR(i2c)));
256 printk(KERN_DEBUG "i2c: log: ");
257 for (i = 0; i < i2c->irqlogidx; i++)
258 printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
259 printk("\n");
260 }
261
262 #else /* ifdef DEBUG */
263
264 #define i2c_debug 0
265
266 #define show_state(i2c) do { } while (0)
267 #define decode_ISR(val) do { } while (0)
268 #define decode_ICR(val) do { } while (0)
269 #define i2c_pxa_scream_blue_murder(i2c, why) do { } while (0)
270
271 #endif /* ifdef DEBUG / else */
272
273 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
274 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
275
276 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
277 {
278 return !(readl(_ICR(i2c)) & ICR_SCLE);
279 }
280
281 static void i2c_pxa_abort(struct pxa_i2c *i2c)
282 {
283 int i = 250;
284
285 if (i2c_pxa_is_slavemode(i2c)) {
286 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
287 return;
288 }
289
290 while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
291 unsigned long icr = readl(_ICR(i2c));
292
293 icr &= ~ICR_START;
294 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
295
296 writel(icr, _ICR(i2c));
297
298 show_state(i2c);
299
300 mdelay(1);
301 i --;
302 }
303
304 writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
305 _ICR(i2c));
306 }
307
308 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
309 {
310 int timeout = DEF_TIMEOUT;
311
312 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
313 if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
314 timeout += 4;
315
316 msleep(2);
317 show_state(i2c);
318 }
319
320 if (timeout < 0)
321 show_state(i2c);
322
323 return timeout < 0 ? I2C_RETRY : 0;
324 }
325
326 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
327 {
328 unsigned long timeout = jiffies + HZ*4;
329
330 while (time_before(jiffies, timeout)) {
331 if (i2c_debug > 1)
332 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
333 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
334
335 if (readl(_ISR(i2c)) & ISR_SAD) {
336 if (i2c_debug > 0)
337 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
338 goto out;
339 }
340
341 /* wait for unit and bus being not busy, and we also do a
342 * quick check of the i2c lines themselves to ensure they've
343 * gone high...
344 */
345 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
346 if (i2c_debug > 0)
347 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
348 return 1;
349 }
350
351 msleep(1);
352 }
353
354 if (i2c_debug > 0)
355 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
356 out:
357 return 0;
358 }
359
360 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
361 {
362 if (i2c_debug)
363 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
364
365 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
366 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
367 if (!i2c_pxa_wait_master(i2c)) {
368 dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
369 return I2C_RETRY;
370 }
371 }
372
373 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
374 return 0;
375 }
376
377 #ifdef CONFIG_I2C_PXA_SLAVE
378 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
379 {
380 unsigned long timeout = jiffies + HZ*1;
381
382 /* wait for stop */
383
384 show_state(i2c);
385
386 while (time_before(jiffies, timeout)) {
387 if (i2c_debug > 1)
388 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
389 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
390
391 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
392 (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
393 (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
394 if (i2c_debug > 1)
395 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
396 return 1;
397 }
398
399 msleep(1);
400 }
401
402 if (i2c_debug > 0)
403 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
404 return 0;
405 }
406
407 /*
408 * clear the hold on the bus, and take of anything else
409 * that has been configured
410 */
411 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
412 {
413 show_state(i2c);
414
415 if (errcode < 0) {
416 udelay(100); /* simple delay */
417 } else {
418 /* we need to wait for the stop condition to end */
419
420 /* if we where in stop, then clear... */
421 if (readl(_ICR(i2c)) & ICR_STOP) {
422 udelay(100);
423 writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
424 }
425
426 if (!i2c_pxa_wait_slave(i2c)) {
427 dev_err(&i2c->adap.dev, "%s: wait timedout\n",
428 __func__);
429 return;
430 }
431 }
432
433 writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
434 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
435
436 if (i2c_debug) {
437 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
438 decode_ICR(readl(_ICR(i2c)));
439 }
440 }
441 #else
442 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
443 #endif
444
445 static void i2c_pxa_reset(struct pxa_i2c *i2c)
446 {
447 pr_debug("Resetting I2C Controller Unit\n");
448
449 /* abort any transfer currently under way */
450 i2c_pxa_abort(i2c);
451
452 /* reset according to 9.8 */
453 writel(ICR_UR, _ICR(i2c));
454 writel(I2C_ISR_INIT, _ISR(i2c));
455 writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
456
457 if (i2c->reg_isar)
458 writel(i2c->slave_addr, _ISAR(i2c));
459
460 /* set control register values */
461 writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
462
463 #ifdef CONFIG_I2C_PXA_SLAVE
464 dev_info(&i2c->adap.dev, "Enabling slave mode\n");
465 writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
466 #endif
467
468 i2c_pxa_set_slave(i2c, 0);
469
470 /* enable unit */
471 writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
472 udelay(100);
473 }
474
475
476 #ifdef CONFIG_I2C_PXA_SLAVE
477 /*
478 * PXA I2C Slave mode
479 */
480
481 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
482 {
483 if (isr & ISR_BED) {
484 /* what should we do here? */
485 } else {
486 int ret = 0;
487
488 if (i2c->slave != NULL)
489 ret = i2c->slave->read(i2c->slave->data);
490
491 writel(ret, _IDBR(i2c));
492 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */
493 }
494 }
495
496 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
497 {
498 unsigned int byte = readl(_IDBR(i2c));
499
500 if (i2c->slave != NULL)
501 i2c->slave->write(i2c->slave->data, byte);
502
503 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
504 }
505
506 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
507 {
508 int timeout;
509
510 if (i2c_debug > 0)
511 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
512 (isr & ISR_RWM) ? 'r' : 't');
513
514 if (i2c->slave != NULL)
515 i2c->slave->event(i2c->slave->data,
516 (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
517
518 /*
519 * slave could interrupt in the middle of us generating a
520 * start condition... if this happens, we'd better back off
521 * and stop holding the poor thing up
522 */
523 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
524 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
525
526 timeout = 0x10000;
527
528 while (1) {
529 if ((readl(_IBMR(i2c)) & 2) == 2)
530 break;
531
532 timeout--;
533
534 if (timeout <= 0) {
535 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
536 break;
537 }
538 }
539
540 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
541 }
542
543 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
544 {
545 if (i2c_debug > 2)
546 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
547
548 if (i2c->slave != NULL)
549 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
550
551 if (i2c_debug > 2)
552 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
553
554 /*
555 * If we have a master-mode message waiting,
556 * kick it off now that the slave has completed.
557 */
558 if (i2c->msg)
559 i2c_pxa_master_complete(i2c, I2C_RETRY);
560 }
561 #else
562 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
563 {
564 if (isr & ISR_BED) {
565 /* what should we do here? */
566 } else {
567 writel(0, _IDBR(i2c));
568 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
569 }
570 }
571
572 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
573 {
574 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
575 }
576
577 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
578 {
579 int timeout;
580
581 /*
582 * slave could interrupt in the middle of us generating a
583 * start condition... if this happens, we'd better back off
584 * and stop holding the poor thing up
585 */
586 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
587 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
588
589 timeout = 0x10000;
590
591 while (1) {
592 if ((readl(_IBMR(i2c)) & 2) == 2)
593 break;
594
595 timeout--;
596
597 if (timeout <= 0) {
598 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
599 break;
600 }
601 }
602
603 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
604 }
605
606 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
607 {
608 if (i2c->msg)
609 i2c_pxa_master_complete(i2c, I2C_RETRY);
610 }
611 #endif
612
613 /*
614 * PXA I2C Master mode
615 */
616
617 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
618 {
619 unsigned int addr = (msg->addr & 0x7f) << 1;
620
621 if (msg->flags & I2C_M_RD)
622 addr |= 1;
623
624 return addr;
625 }
626
627 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
628 {
629 u32 icr;
630
631 /*
632 * Step 1: target slave address into IDBR
633 */
634 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
635
636 /*
637 * Step 2: initiate the write.
638 */
639 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
640 writel(icr | ICR_START | ICR_TB, _ICR(i2c));
641 }
642
643 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
644 {
645 u32 icr;
646
647 /*
648 * Clear the STOP and ACK flags
649 */
650 icr = readl(_ICR(i2c));
651 icr &= ~(ICR_STOP | ICR_ACKNAK);
652 writel(icr, _ICR(i2c));
653 }
654
655 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
656 {
657 /* make timeout the same as for interrupt based functions */
658 long timeout = 2 * DEF_TIMEOUT;
659
660 /*
661 * Wait for the bus to become free.
662 */
663 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
664 udelay(1000);
665 show_state(i2c);
666 }
667
668 if (timeout < 0) {
669 show_state(i2c);
670 dev_err(&i2c->adap.dev,
671 "i2c_pxa: timeout waiting for bus free\n");
672 return I2C_RETRY;
673 }
674
675 /*
676 * Set master mode.
677 */
678 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
679
680 return 0;
681 }
682
683 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
684 struct i2c_msg *msg, int num)
685 {
686 unsigned long timeout = 500000; /* 5 seconds */
687 int ret = 0;
688
689 ret = i2c_pxa_pio_set_master(i2c);
690 if (ret)
691 goto out;
692
693 i2c->msg = msg;
694 i2c->msg_num = num;
695 i2c->msg_idx = 0;
696 i2c->msg_ptr = 0;
697 i2c->irqlogidx = 0;
698
699 i2c_pxa_start_message(i2c);
700
701 while (i2c->msg_num > 0 && --timeout) {
702 i2c_pxa_handler(0, i2c);
703 udelay(10);
704 }
705
706 i2c_pxa_stop_message(i2c);
707
708 /*
709 * We place the return code in i2c->msg_idx.
710 */
711 ret = i2c->msg_idx;
712
713 out:
714 if (timeout == 0)
715 i2c_pxa_scream_blue_murder(i2c, "timeout");
716
717 return ret;
718 }
719
720 /*
721 * We are protected by the adapter bus mutex.
722 */
723 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
724 {
725 long timeout;
726 int ret;
727
728 /*
729 * Wait for the bus to become free.
730 */
731 ret = i2c_pxa_wait_bus_not_busy(i2c);
732 if (ret) {
733 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
734 goto out;
735 }
736
737 /*
738 * Set master mode.
739 */
740 ret = i2c_pxa_set_master(i2c);
741 if (ret) {
742 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
743 goto out;
744 }
745
746 spin_lock_irq(&i2c->lock);
747
748 i2c->msg = msg;
749 i2c->msg_num = num;
750 i2c->msg_idx = 0;
751 i2c->msg_ptr = 0;
752 i2c->irqlogidx = 0;
753
754 i2c_pxa_start_message(i2c);
755
756 spin_unlock_irq(&i2c->lock);
757
758 /*
759 * The rest of the processing occurs in the interrupt handler.
760 */
761 timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
762 i2c_pxa_stop_message(i2c);
763
764 /*
765 * We place the return code in i2c->msg_idx.
766 */
767 ret = i2c->msg_idx;
768
769 if (!timeout && i2c->msg_num) {
770 i2c_pxa_scream_blue_murder(i2c, "timeout");
771 ret = I2C_RETRY;
772 }
773
774 out:
775 return ret;
776 }
777
778 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
779 struct i2c_msg msgs[], int num)
780 {
781 struct pxa_i2c *i2c = adap->algo_data;
782 int ret, i;
783
784 /* If the I2C controller is disabled we need to reset it
785 (probably due to a suspend/resume destroying state). We do
786 this here as we can then avoid worrying about resuming the
787 controller before its users. */
788 if (!(readl(_ICR(i2c)) & ICR_IUE))
789 i2c_pxa_reset(i2c);
790
791 for (i = adap->retries; i >= 0; i--) {
792 ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
793 if (ret != I2C_RETRY)
794 goto out;
795
796 if (i2c_debug)
797 dev_dbg(&adap->dev, "Retrying transmission\n");
798 udelay(100);
799 }
800 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
801 ret = -EREMOTEIO;
802 out:
803 i2c_pxa_set_slave(i2c, ret);
804 return ret;
805 }
806
807 /*
808 * i2c_pxa_master_complete - complete the message and wake up.
809 */
810 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
811 {
812 i2c->msg_ptr = 0;
813 i2c->msg = NULL;
814 i2c->msg_idx ++;
815 i2c->msg_num = 0;
816 if (ret)
817 i2c->msg_idx = ret;
818 if (!i2c->use_pio)
819 wake_up(&i2c->wait);
820 }
821
822 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
823 {
824 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
825
826 again:
827 /*
828 * If ISR_ALD is set, we lost arbitration.
829 */
830 if (isr & ISR_ALD) {
831 /*
832 * Do we need to do anything here? The PXA docs
833 * are vague about what happens.
834 */
835 i2c_pxa_scream_blue_murder(i2c, "ALD set");
836
837 /*
838 * We ignore this error. We seem to see spurious ALDs
839 * for seemingly no reason. If we handle them as I think
840 * they should, we end up causing an I2C error, which
841 * is painful for some systems.
842 */
843 return; /* ignore */
844 }
845
846 if (isr & ISR_BED) {
847 int ret = BUS_ERROR;
848
849 /*
850 * I2C bus error - either the device NAK'd us, or
851 * something more serious happened. If we were NAK'd
852 * on the initial address phase, we can retry.
853 */
854 if (isr & ISR_ACKNAK) {
855 if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
856 ret = I2C_RETRY;
857 else
858 ret = XFER_NAKED;
859 }
860 i2c_pxa_master_complete(i2c, ret);
861 } else if (isr & ISR_RWM) {
862 /*
863 * Read mode. We have just sent the address byte, and
864 * now we must initiate the transfer.
865 */
866 if (i2c->msg_ptr == i2c->msg->len - 1 &&
867 i2c->msg_idx == i2c->msg_num - 1)
868 icr |= ICR_STOP | ICR_ACKNAK;
869
870 icr |= ICR_ALDIE | ICR_TB;
871 } else if (i2c->msg_ptr < i2c->msg->len) {
872 /*
873 * Write mode. Write the next data byte.
874 */
875 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
876
877 icr |= ICR_ALDIE | ICR_TB;
878
879 /*
880 * If this is the last byte of the last message, send
881 * a STOP.
882 */
883 if (i2c->msg_ptr == i2c->msg->len &&
884 i2c->msg_idx == i2c->msg_num - 1)
885 icr |= ICR_STOP;
886 } else if (i2c->msg_idx < i2c->msg_num - 1) {
887 /*
888 * Next segment of the message.
889 */
890 i2c->msg_ptr = 0;
891 i2c->msg_idx ++;
892 i2c->msg++;
893
894 /*
895 * If we aren't doing a repeated start and address,
896 * go back and try to send the next byte. Note that
897 * we do not support switching the R/W direction here.
898 */
899 if (i2c->msg->flags & I2C_M_NOSTART)
900 goto again;
901
902 /*
903 * Write the next address.
904 */
905 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
906
907 /*
908 * And trigger a repeated start, and send the byte.
909 */
910 icr &= ~ICR_ALDIE;
911 icr |= ICR_START | ICR_TB;
912 } else {
913 if (i2c->msg->len == 0) {
914 /*
915 * Device probes have a message length of zero
916 * and need the bus to be reset before it can
917 * be used again.
918 */
919 i2c_pxa_reset(i2c);
920 }
921 i2c_pxa_master_complete(i2c, 0);
922 }
923
924 i2c->icrlog[i2c->irqlogidx-1] = icr;
925
926 writel(icr, _ICR(i2c));
927 show_state(i2c);
928 }
929
930 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
931 {
932 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
933
934 /*
935 * Read the byte.
936 */
937 i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
938
939 if (i2c->msg_ptr < i2c->msg->len) {
940 /*
941 * If this is the last byte of the last
942 * message, send a STOP.
943 */
944 if (i2c->msg_ptr == i2c->msg->len - 1)
945 icr |= ICR_STOP | ICR_ACKNAK;
946
947 icr |= ICR_ALDIE | ICR_TB;
948 } else {
949 i2c_pxa_master_complete(i2c, 0);
950 }
951
952 i2c->icrlog[i2c->irqlogidx-1] = icr;
953
954 writel(icr, _ICR(i2c));
955 }
956
957 #define VALID_INT_SOURCE (ISR_SSD | ISR_ALD | ISR_ITE | ISR_IRF | \
958 ISR_SAD | ISR_BED)
959 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
960 {
961 struct pxa_i2c *i2c = dev_id;
962 u32 isr = readl(_ISR(i2c));
963
964 if (!(isr & VALID_INT_SOURCE))
965 return IRQ_NONE;
966
967 if (i2c_debug > 2 && 0) {
968 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
969 __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
970 decode_ISR(isr);
971 }
972
973 if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
974 i2c->isrlog[i2c->irqlogidx++] = isr;
975
976 show_state(i2c);
977
978 /*
979 * Always clear all pending IRQs.
980 */
981 writel(isr & VALID_INT_SOURCE, _ISR(i2c));
982
983 if (isr & ISR_SAD)
984 i2c_pxa_slave_start(i2c, isr);
985 if (isr & ISR_SSD)
986 i2c_pxa_slave_stop(i2c);
987
988 if (i2c_pxa_is_slavemode(i2c)) {
989 if (isr & ISR_ITE)
990 i2c_pxa_slave_txempty(i2c, isr);
991 if (isr & ISR_IRF)
992 i2c_pxa_slave_rxfull(i2c, isr);
993 } else if (i2c->msg) {
994 if (isr & ISR_ITE)
995 i2c_pxa_irq_txempty(i2c, isr);
996 if (isr & ISR_IRF)
997 i2c_pxa_irq_rxfull(i2c, isr);
998 } else {
999 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
1000 }
1001
1002 return IRQ_HANDLED;
1003 }
1004
1005
1006 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
1007 {
1008 struct pxa_i2c *i2c = adap->algo_data;
1009 int ret, i;
1010
1011 for (i = adap->retries; i >= 0; i--) {
1012 ret = i2c_pxa_do_xfer(i2c, msgs, num);
1013 if (ret != I2C_RETRY)
1014 goto out;
1015
1016 if (i2c_debug)
1017 dev_dbg(&adap->dev, "Retrying transmission\n");
1018 udelay(100);
1019 }
1020 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
1021 ret = -EREMOTEIO;
1022 out:
1023 i2c_pxa_set_slave(i2c, ret);
1024 return ret;
1025 }
1026
1027 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
1028 {
1029 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
1030 }
1031
1032 static const struct i2c_algorithm i2c_pxa_algorithm = {
1033 .master_xfer = i2c_pxa_xfer,
1034 .functionality = i2c_pxa_functionality,
1035 };
1036
1037 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
1038 .master_xfer = i2c_pxa_pio_xfer,
1039 .functionality = i2c_pxa_functionality,
1040 };
1041
1042 static struct of_device_id i2c_pxa_dt_ids[] = {
1043 { .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX },
1044 { .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX },
1045 { .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA2XX },
1046 {}
1047 };
1048 MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
1049
1050 static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
1051 enum pxa_i2c_types *i2c_types)
1052 {
1053 struct device_node *np = pdev->dev.of_node;
1054 const struct of_device_id *of_id =
1055 of_match_device(i2c_pxa_dt_ids, &pdev->dev);
1056 int ret;
1057
1058 if (!of_id)
1059 return 1;
1060 ret = of_alias_get_id(np, "i2c");
1061 if (ret < 0) {
1062 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1063 return ret;
1064 }
1065 pdev->id = ret;
1066 if (of_get_property(np, "mrvl,i2c-polling", NULL))
1067 i2c->use_pio = 1;
1068 if (of_get_property(np, "mrvl,i2c-fast-mode", NULL))
1069 i2c->fast_mode = 1;
1070 *i2c_types = (u32)(of_id->data);
1071 return 0;
1072 }
1073
1074 static int i2c_pxa_probe_pdata(struct platform_device *pdev,
1075 struct pxa_i2c *i2c,
1076 enum pxa_i2c_types *i2c_types)
1077 {
1078 struct i2c_pxa_platform_data *plat = pdev->dev.platform_data;
1079 const struct platform_device_id *id = platform_get_device_id(pdev);
1080
1081 *i2c_types = id->driver_data;
1082 if (plat) {
1083 i2c->use_pio = plat->use_pio;
1084 i2c->fast_mode = plat->fast_mode;
1085 }
1086 return 0;
1087 }
1088
1089 static int i2c_pxa_probe(struct platform_device *dev)
1090 {
1091 struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
1092 enum pxa_i2c_types i2c_type;
1093 struct pxa_i2c *i2c;
1094 struct resource *res = NULL;
1095 int ret, irq;
1096
1097 i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
1098 if (!i2c) {
1099 ret = -ENOMEM;
1100 goto emalloc;
1101 }
1102
1103 ret = i2c_pxa_probe_dt(dev, i2c, &i2c_type);
1104 if (ret > 0)
1105 ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
1106 if (ret < 0)
1107 goto eclk;
1108
1109 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
1110 irq = platform_get_irq(dev, 0);
1111 if (res == NULL || irq < 0) {
1112 ret = -ENODEV;
1113 goto eclk;
1114 }
1115
1116 if (!request_mem_region(res->start, resource_size(res), res->name)) {
1117 ret = -ENOMEM;
1118 goto eclk;
1119 }
1120
1121 i2c->adap.owner = THIS_MODULE;
1122 i2c->adap.retries = 5;
1123
1124 spin_lock_init(&i2c->lock);
1125 init_waitqueue_head(&i2c->wait);
1126
1127 i2c->adap.nr = dev->id;
1128 snprintf(i2c->adap.name, sizeof(i2c->adap.name), "pxa_i2c-i2c.%u",
1129 i2c->adap.nr);
1130
1131 i2c->clk = clk_get(&dev->dev, NULL);
1132 if (IS_ERR(i2c->clk)) {
1133 ret = PTR_ERR(i2c->clk);
1134 goto eclk;
1135 }
1136
1137 i2c->reg_base = ioremap(res->start, resource_size(res));
1138 if (!i2c->reg_base) {
1139 ret = -EIO;
1140 goto eremap;
1141 }
1142
1143 i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
1144 i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr;
1145 i2c->reg_icr = i2c->reg_base + pxa_reg_layout[i2c_type].icr;
1146 i2c->reg_isr = i2c->reg_base + pxa_reg_layout[i2c_type].isr;
1147 if (i2c_type != REGS_CE4100)
1148 i2c->reg_isar = i2c->reg_base + pxa_reg_layout[i2c_type].isar;
1149
1150 i2c->iobase = res->start;
1151 i2c->iosize = resource_size(res);
1152
1153 i2c->irq = irq;
1154
1155 i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1156
1157 if (plat) {
1158 #ifdef CONFIG_I2C_PXA_SLAVE
1159 i2c->slave_addr = plat->slave_addr;
1160 i2c->slave = plat->slave;
1161 #endif
1162 i2c->adap.class = plat->class;
1163 }
1164
1165 clk_enable(i2c->clk);
1166
1167 if (i2c->use_pio) {
1168 i2c->adap.algo = &i2c_pxa_pio_algorithm;
1169 } else {
1170 i2c->adap.algo = &i2c_pxa_algorithm;
1171 ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
1172 i2c->adap.name, i2c);
1173 if (ret)
1174 goto ereqirq;
1175 }
1176
1177 i2c_pxa_reset(i2c);
1178
1179 i2c->adap.algo_data = i2c;
1180 i2c->adap.dev.parent = &dev->dev;
1181 #ifdef CONFIG_OF
1182 i2c->adap.dev.of_node = dev->dev.of_node;
1183 #endif
1184
1185 ret = i2c_add_numbered_adapter(&i2c->adap);
1186 if (ret < 0) {
1187 printk(KERN_INFO "I2C: Failed to add bus\n");
1188 goto eadapt;
1189 }
1190 of_i2c_register_devices(&i2c->adap);
1191
1192 platform_set_drvdata(dev, i2c);
1193
1194 #ifdef CONFIG_I2C_PXA_SLAVE
1195 printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
1196 dev_name(&i2c->adap.dev), i2c->slave_addr);
1197 #else
1198 printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
1199 dev_name(&i2c->adap.dev));
1200 #endif
1201 return 0;
1202
1203 eadapt:
1204 if (!i2c->use_pio)
1205 free_irq(irq, i2c);
1206 ereqirq:
1207 clk_disable(i2c->clk);
1208 iounmap(i2c->reg_base);
1209 eremap:
1210 clk_put(i2c->clk);
1211 eclk:
1212 kfree(i2c);
1213 emalloc:
1214 release_mem_region(res->start, resource_size(res));
1215 return ret;
1216 }
1217
1218 static int __exit i2c_pxa_remove(struct platform_device *dev)
1219 {
1220 struct pxa_i2c *i2c = platform_get_drvdata(dev);
1221
1222 platform_set_drvdata(dev, NULL);
1223
1224 i2c_del_adapter(&i2c->adap);
1225 if (!i2c->use_pio)
1226 free_irq(i2c->irq, i2c);
1227
1228 clk_disable(i2c->clk);
1229 clk_put(i2c->clk);
1230
1231 iounmap(i2c->reg_base);
1232 release_mem_region(i2c->iobase, i2c->iosize);
1233 kfree(i2c);
1234
1235 return 0;
1236 }
1237
1238 #ifdef CONFIG_PM
1239 static int i2c_pxa_suspend_noirq(struct device *dev)
1240 {
1241 struct platform_device *pdev = to_platform_device(dev);
1242 struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1243
1244 clk_disable(i2c->clk);
1245
1246 return 0;
1247 }
1248
1249 static int i2c_pxa_resume_noirq(struct device *dev)
1250 {
1251 struct platform_device *pdev = to_platform_device(dev);
1252 struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1253
1254 clk_enable(i2c->clk);
1255 i2c_pxa_reset(i2c);
1256
1257 return 0;
1258 }
1259
1260 static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
1261 .suspend_noirq = i2c_pxa_suspend_noirq,
1262 .resume_noirq = i2c_pxa_resume_noirq,
1263 };
1264
1265 #define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
1266 #else
1267 #define I2C_PXA_DEV_PM_OPS NULL
1268 #endif
1269
1270 static struct platform_driver i2c_pxa_driver = {
1271 .probe = i2c_pxa_probe,
1272 .remove = __exit_p(i2c_pxa_remove),
1273 .driver = {
1274 .name = "pxa2xx-i2c",
1275 .owner = THIS_MODULE,
1276 .pm = I2C_PXA_DEV_PM_OPS,
1277 .of_match_table = i2c_pxa_dt_ids,
1278 },
1279 .id_table = i2c_pxa_id_table,
1280 };
1281
1282 static int __init i2c_adap_pxa_init(void)
1283 {
1284 return platform_driver_register(&i2c_pxa_driver);
1285 }
1286
1287 static void __exit i2c_adap_pxa_exit(void)
1288 {
1289 platform_driver_unregister(&i2c_pxa_driver);
1290 }
1291
1292 MODULE_LICENSE("GPL");
1293 MODULE_ALIAS("platform:pxa2xx-i2c");
1294
1295 subsys_initcall(i2c_adap_pxa_init);
1296 module_exit(i2c_adap_pxa_exit);
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