pandora: defconfig: update
[pandora-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_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);