PM / sleep: Asynchronous threads for suspend_noirq
[linux/fpc-iii.git] / drivers / i2c / busses / i2c-pxa.c
blobbbe6dfbc5c05da4917ad0d295f2c32659ce29dfc
1 /*
2 * i2c_adap_pxa.c
4 * I2C adapter for the PXA I2C bus access.
6 * Copyright (C) 2002 Intrinsyc Software Inc.
7 * Copyright (C) 2004-2005 Deep Blue Solutions Ltd.
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.
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]
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/platform_device.h>
35 #include <linux/err.h>
36 #include <linux/clk.h>
37 #include <linux/slab.h>
38 #include <linux/io.h>
39 #include <linux/i2c/pxa-i2c.h>
41 #include <asm/irq.h>
43 struct pxa_reg_layout {
44 u32 ibmr;
45 u32 idbr;
46 u32 icr;
47 u32 isr;
48 u32 isar;
51 enum pxa_i2c_types {
52 REGS_PXA2XX,
53 REGS_PXA3XX,
54 REGS_CE4100,
58 * I2C registers definitions
60 static struct pxa_reg_layout pxa_reg_layout[] = {
61 [REGS_PXA2XX] = {
62 .ibmr = 0x00,
63 .idbr = 0x08,
64 .icr = 0x10,
65 .isr = 0x18,
66 .isar = 0x20,
68 [REGS_PXA3XX] = {
69 .ibmr = 0x00,
70 .idbr = 0x04,
71 .icr = 0x08,
72 .isr = 0x0c,
73 .isar = 0x10,
75 [REGS_CE4100] = {
76 .ibmr = 0x14,
77 .idbr = 0x0c,
78 .icr = 0x00,
79 .isr = 0x04,
80 /* no isar register */
84 static const struct platform_device_id i2c_pxa_id_table[] = {
85 { "pxa2xx-i2c", REGS_PXA2XX },
86 { "pxa3xx-pwri2c", REGS_PXA3XX },
87 { "ce4100-i2c", REGS_CE4100 },
88 { },
90 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
93 * I2C bit definitions
96 #define ICR_START (1 << 0) /* start bit */
97 #define ICR_STOP (1 << 1) /* stop bit */
98 #define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
99 #define ICR_TB (1 << 3) /* transfer byte bit */
100 #define ICR_MA (1 << 4) /* master abort */
101 #define ICR_SCLE (1 << 5) /* master clock enable */
102 #define ICR_IUE (1 << 6) /* unit enable */
103 #define ICR_GCD (1 << 7) /* general call disable */
104 #define ICR_ITEIE (1 << 8) /* enable tx interrupts */
105 #define ICR_IRFIE (1 << 9) /* enable rx interrupts */
106 #define ICR_BEIE (1 << 10) /* enable bus error ints */
107 #define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
108 #define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
109 #define ICR_SADIE (1 << 13) /* slave address detected int enable */
110 #define ICR_UR (1 << 14) /* unit reset */
111 #define ICR_FM (1 << 15) /* fast mode */
112 #define ICR_HS (1 << 16) /* High Speed mode */
113 #define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */
115 #define ISR_RWM (1 << 0) /* read/write mode */
116 #define ISR_ACKNAK (1 << 1) /* ack/nak status */
117 #define ISR_UB (1 << 2) /* unit busy */
118 #define ISR_IBB (1 << 3) /* bus busy */
119 #define ISR_SSD (1 << 4) /* slave stop detected */
120 #define ISR_ALD (1 << 5) /* arbitration loss detected */
121 #define ISR_ITE (1 << 6) /* tx buffer empty */
122 #define ISR_IRF (1 << 7) /* rx buffer full */
123 #define ISR_GCAD (1 << 8) /* general call address detected */
124 #define ISR_SAD (1 << 9) /* slave address detected */
125 #define ISR_BED (1 << 10) /* bus error no ACK/NAK */
127 struct pxa_i2c {
128 spinlock_t lock;
129 wait_queue_head_t wait;
130 struct i2c_msg *msg;
131 unsigned int msg_num;
132 unsigned int msg_idx;
133 unsigned int msg_ptr;
134 unsigned int slave_addr;
136 struct i2c_adapter adap;
137 struct clk *clk;
138 #ifdef CONFIG_I2C_PXA_SLAVE
139 struct i2c_slave_client *slave;
140 #endif
142 unsigned int irqlogidx;
143 u32 isrlog[32];
144 u32 icrlog[32];
146 void __iomem *reg_base;
147 void __iomem *reg_ibmr;
148 void __iomem *reg_idbr;
149 void __iomem *reg_icr;
150 void __iomem *reg_isr;
151 void __iomem *reg_isar;
153 unsigned long iobase;
154 unsigned long iosize;
156 int irq;
157 unsigned int use_pio :1;
158 unsigned int fast_mode :1;
159 unsigned int high_mode:1;
160 unsigned char master_code;
161 unsigned long rate;
162 bool highmode_enter;
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)
172 * I2C Slave mode address
174 #define I2C_PXA_SLAVE_ADDR 0x1
176 #ifdef DEBUG
178 struct bits {
179 u32 mask;
180 const char *set;
181 const char *unset;
183 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
185 static inline void
186 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
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++;
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),
211 static void decode_ISR(unsigned int val)
213 decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
214 printk("\n");
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"),
235 #ifdef CONFIG_I2C_PXA_SLAVE
236 static void decode_ICR(unsigned int val)
238 decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
239 printk("\n");
241 #endif
243 static unsigned int i2c_debug = DEBUG;
245 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
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)));
251 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
253 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
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");
267 #else /* ifdef DEBUG */
269 #define i2c_debug 0
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)
276 #endif /* ifdef DEBUG / else */
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);
281 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
283 return !(readl(_ICR(i2c)) & ICR_SCLE);
286 static void i2c_pxa_abort(struct pxa_i2c *i2c)
288 int i = 250;
290 if (i2c_pxa_is_slavemode(i2c)) {
291 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
292 return;
295 while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
296 unsigned long icr = readl(_ICR(i2c));
298 icr &= ~ICR_START;
299 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
301 writel(icr, _ICR(i2c));
303 show_state(i2c);
305 mdelay(1);
306 i --;
309 writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
310 _ICR(i2c));
313 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
315 int timeout = DEF_TIMEOUT;
317 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
318 if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
319 timeout += 4;
321 msleep(2);
322 show_state(i2c);
325 if (timeout < 0)
326 show_state(i2c);
328 return timeout < 0 ? I2C_RETRY : 0;
331 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
333 unsigned long timeout = jiffies + HZ*4;
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)));
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;
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...
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;
356 msleep(1);
359 if (i2c_debug > 0)
360 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
361 out:
362 return 0;
365 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
367 if (i2c_debug)
368 dev_dbg(&i2c->adap.dev, "setting to bus master\n");
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;
378 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
379 return 0;
382 #ifdef CONFIG_I2C_PXA_SLAVE
383 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
385 unsigned long timeout = jiffies + HZ*1;
387 /* wait for stop */
389 show_state(i2c);
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)));
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;
404 msleep(1);
407 if (i2c_debug > 0)
408 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
409 return 0;
413 * clear the hold on the bus, and take of anything else
414 * that has been configured
416 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
418 show_state(i2c);
420 if (errcode < 0) {
421 udelay(100); /* simple delay */
422 } else {
423 /* we need to wait for the stop condition to end */
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));
431 if (!i2c_pxa_wait_slave(i2c)) {
432 dev_err(&i2c->adap.dev, "%s: wait timedout\n",
433 __func__);
434 return;
438 writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
439 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
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)));
446 #else
447 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
448 #endif
450 static void i2c_pxa_reset(struct pxa_i2c *i2c)
452 pr_debug("Resetting I2C Controller Unit\n");
454 /* abort any transfer currently under way */
455 i2c_pxa_abort(i2c);
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));
462 if (i2c->reg_isar)
463 writel(i2c->slave_addr, _ISAR(i2c));
465 /* set control register values */
466 writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
467 writel(readl(_ICR(i2c)) | (i2c->high_mode ? ICR_HS : 0), _ICR(i2c));
469 #ifdef CONFIG_I2C_PXA_SLAVE
470 dev_info(&i2c->adap.dev, "Enabling slave mode\n");
471 writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
472 #endif
474 i2c_pxa_set_slave(i2c, 0);
476 /* enable unit */
477 writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
478 udelay(100);
482 #ifdef CONFIG_I2C_PXA_SLAVE
484 * PXA I2C Slave mode
487 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
489 if (isr & ISR_BED) {
490 /* what should we do here? */
491 } else {
492 int ret = 0;
494 if (i2c->slave != NULL)
495 ret = i2c->slave->read(i2c->slave->data);
497 writel(ret, _IDBR(i2c));
498 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */
502 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
504 unsigned int byte = readl(_IDBR(i2c));
506 if (i2c->slave != NULL)
507 i2c->slave->write(i2c->slave->data, byte);
509 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
512 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
514 int timeout;
516 if (i2c_debug > 0)
517 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
518 (isr & ISR_RWM) ? 'r' : 't');
520 if (i2c->slave != NULL)
521 i2c->slave->event(i2c->slave->data,
522 (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
525 * slave could interrupt in the middle of us generating a
526 * start condition... if this happens, we'd better back off
527 * and stop holding the poor thing up
529 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
530 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
532 timeout = 0x10000;
534 while (1) {
535 if ((readl(_IBMR(i2c)) & 2) == 2)
536 break;
538 timeout--;
540 if (timeout <= 0) {
541 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
542 break;
546 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
549 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
551 if (i2c_debug > 2)
552 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
554 if (i2c->slave != NULL)
555 i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
557 if (i2c_debug > 2)
558 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
561 * If we have a master-mode message waiting,
562 * kick it off now that the slave has completed.
564 if (i2c->msg)
565 i2c_pxa_master_complete(i2c, I2C_RETRY);
567 #else
568 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
570 if (isr & ISR_BED) {
571 /* what should we do here? */
572 } else {
573 writel(0, _IDBR(i2c));
574 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
578 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
580 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
583 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
585 int timeout;
588 * slave could interrupt in the middle of us generating a
589 * start condition... if this happens, we'd better back off
590 * and stop holding the poor thing up
592 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
593 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
595 timeout = 0x10000;
597 while (1) {
598 if ((readl(_IBMR(i2c)) & 2) == 2)
599 break;
601 timeout--;
603 if (timeout <= 0) {
604 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
605 break;
609 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
612 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
614 if (i2c->msg)
615 i2c_pxa_master_complete(i2c, I2C_RETRY);
617 #endif
620 * PXA I2C Master mode
623 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
625 unsigned int addr = (msg->addr & 0x7f) << 1;
627 if (msg->flags & I2C_M_RD)
628 addr |= 1;
630 return addr;
633 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
635 u32 icr;
638 * Step 1: target slave address into IDBR
640 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
643 * Step 2: initiate the write.
645 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
646 writel(icr | ICR_START | ICR_TB, _ICR(i2c));
649 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
651 u32 icr;
654 * Clear the STOP and ACK flags
656 icr = readl(_ICR(i2c));
657 icr &= ~(ICR_STOP | ICR_ACKNAK);
658 writel(icr, _ICR(i2c));
661 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
663 /* make timeout the same as for interrupt based functions */
664 long timeout = 2 * DEF_TIMEOUT;
667 * Wait for the bus to become free.
669 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
670 udelay(1000);
671 show_state(i2c);
674 if (timeout < 0) {
675 show_state(i2c);
676 dev_err(&i2c->adap.dev,
677 "i2c_pxa: timeout waiting for bus free\n");
678 return I2C_RETRY;
682 * Set master mode.
684 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
686 return 0;
690 * PXA I2C send master code
691 * 1. Load master code to IDBR and send it.
692 * Note for HS mode, set ICR [GPIOEN].
693 * 2. Wait until win arbitration.
695 static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c)
697 u32 icr;
698 long timeout;
700 spin_lock_irq(&i2c->lock);
701 i2c->highmode_enter = true;
702 writel(i2c->master_code, _IDBR(i2c));
704 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
705 icr |= ICR_GPIOEN | ICR_START | ICR_TB | ICR_ITEIE;
706 writel(icr, _ICR(i2c));
708 spin_unlock_irq(&i2c->lock);
709 timeout = wait_event_timeout(i2c->wait,
710 i2c->highmode_enter == false, HZ * 1);
712 i2c->highmode_enter = false;
714 return (timeout == 0) ? I2C_RETRY : 0;
717 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
718 struct i2c_msg *msg, int num)
720 unsigned long timeout = 500000; /* 5 seconds */
721 int ret = 0;
723 ret = i2c_pxa_pio_set_master(i2c);
724 if (ret)
725 goto out;
727 i2c->msg = msg;
728 i2c->msg_num = num;
729 i2c->msg_idx = 0;
730 i2c->msg_ptr = 0;
731 i2c->irqlogidx = 0;
733 i2c_pxa_start_message(i2c);
735 while (i2c->msg_num > 0 && --timeout) {
736 i2c_pxa_handler(0, i2c);
737 udelay(10);
740 i2c_pxa_stop_message(i2c);
743 * We place the return code in i2c->msg_idx.
745 ret = i2c->msg_idx;
747 out:
748 if (timeout == 0)
749 i2c_pxa_scream_blue_murder(i2c, "timeout");
751 return ret;
755 * We are protected by the adapter bus mutex.
757 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
759 long timeout;
760 int ret;
763 * Wait for the bus to become free.
765 ret = i2c_pxa_wait_bus_not_busy(i2c);
766 if (ret) {
767 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
768 goto out;
772 * Set master mode.
774 ret = i2c_pxa_set_master(i2c);
775 if (ret) {
776 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
777 goto out;
780 if (i2c->high_mode) {
781 ret = i2c_pxa_send_mastercode(i2c);
782 if (ret) {
783 dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
784 goto out;
788 spin_lock_irq(&i2c->lock);
790 i2c->msg = msg;
791 i2c->msg_num = num;
792 i2c->msg_idx = 0;
793 i2c->msg_ptr = 0;
794 i2c->irqlogidx = 0;
796 i2c_pxa_start_message(i2c);
798 spin_unlock_irq(&i2c->lock);
801 * The rest of the processing occurs in the interrupt handler.
803 timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
804 i2c_pxa_stop_message(i2c);
807 * We place the return code in i2c->msg_idx.
809 ret = i2c->msg_idx;
811 if (!timeout && i2c->msg_num) {
812 i2c_pxa_scream_blue_murder(i2c, "timeout");
813 ret = I2C_RETRY;
816 out:
817 return ret;
820 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
821 struct i2c_msg msgs[], int num)
823 struct pxa_i2c *i2c = adap->algo_data;
824 int ret, i;
826 /* If the I2C controller is disabled we need to reset it
827 (probably due to a suspend/resume destroying state). We do
828 this here as we can then avoid worrying about resuming the
829 controller before its users. */
830 if (!(readl(_ICR(i2c)) & ICR_IUE))
831 i2c_pxa_reset(i2c);
833 for (i = adap->retries; i >= 0; i--) {
834 ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
835 if (ret != I2C_RETRY)
836 goto out;
838 if (i2c_debug)
839 dev_dbg(&adap->dev, "Retrying transmission\n");
840 udelay(100);
842 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
843 ret = -EREMOTEIO;
844 out:
845 i2c_pxa_set_slave(i2c, ret);
846 return ret;
850 * i2c_pxa_master_complete - complete the message and wake up.
852 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
854 i2c->msg_ptr = 0;
855 i2c->msg = NULL;
856 i2c->msg_idx ++;
857 i2c->msg_num = 0;
858 if (ret)
859 i2c->msg_idx = ret;
860 if (!i2c->use_pio)
861 wake_up(&i2c->wait);
864 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
866 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
868 again:
870 * If ISR_ALD is set, we lost arbitration.
872 if (isr & ISR_ALD) {
874 * Do we need to do anything here? The PXA docs
875 * are vague about what happens.
877 i2c_pxa_scream_blue_murder(i2c, "ALD set");
880 * We ignore this error. We seem to see spurious ALDs
881 * for seemingly no reason. If we handle them as I think
882 * they should, we end up causing an I2C error, which
883 * is painful for some systems.
885 return; /* ignore */
888 if (isr & ISR_BED) {
889 int ret = BUS_ERROR;
892 * I2C bus error - either the device NAK'd us, or
893 * something more serious happened. If we were NAK'd
894 * on the initial address phase, we can retry.
896 if (isr & ISR_ACKNAK) {
897 if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
898 ret = I2C_RETRY;
899 else
900 ret = XFER_NAKED;
902 i2c_pxa_master_complete(i2c, ret);
903 } else if (isr & ISR_RWM) {
905 * Read mode. We have just sent the address byte, and
906 * now we must initiate the transfer.
908 if (i2c->msg_ptr == i2c->msg->len - 1 &&
909 i2c->msg_idx == i2c->msg_num - 1)
910 icr |= ICR_STOP | ICR_ACKNAK;
912 icr |= ICR_ALDIE | ICR_TB;
913 } else if (i2c->msg_ptr < i2c->msg->len) {
915 * Write mode. Write the next data byte.
917 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
919 icr |= ICR_ALDIE | ICR_TB;
922 * If this is the last byte of the last message, send
923 * a STOP.
925 if (i2c->msg_ptr == i2c->msg->len &&
926 i2c->msg_idx == i2c->msg_num - 1)
927 icr |= ICR_STOP;
928 } else if (i2c->msg_idx < i2c->msg_num - 1) {
930 * Next segment of the message.
932 i2c->msg_ptr = 0;
933 i2c->msg_idx ++;
934 i2c->msg++;
937 * If we aren't doing a repeated start and address,
938 * go back and try to send the next byte. Note that
939 * we do not support switching the R/W direction here.
941 if (i2c->msg->flags & I2C_M_NOSTART)
942 goto again;
945 * Write the next address.
947 writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
950 * And trigger a repeated start, and send the byte.
952 icr &= ~ICR_ALDIE;
953 icr |= ICR_START | ICR_TB;
954 } else {
955 if (i2c->msg->len == 0) {
957 * Device probes have a message length of zero
958 * and need the bus to be reset before it can
959 * be used again.
961 i2c_pxa_reset(i2c);
963 i2c_pxa_master_complete(i2c, 0);
966 i2c->icrlog[i2c->irqlogidx-1] = icr;
968 writel(icr, _ICR(i2c));
969 show_state(i2c);
972 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
974 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
977 * Read the byte.
979 i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
981 if (i2c->msg_ptr < i2c->msg->len) {
983 * If this is the last byte of the last
984 * message, send a STOP.
986 if (i2c->msg_ptr == i2c->msg->len - 1)
987 icr |= ICR_STOP | ICR_ACKNAK;
989 icr |= ICR_ALDIE | ICR_TB;
990 } else {
991 i2c_pxa_master_complete(i2c, 0);
994 i2c->icrlog[i2c->irqlogidx-1] = icr;
996 writel(icr, _ICR(i2c));
999 #define VALID_INT_SOURCE (ISR_SSD | ISR_ALD | ISR_ITE | ISR_IRF | \
1000 ISR_SAD | ISR_BED)
1001 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
1003 struct pxa_i2c *i2c = dev_id;
1004 u32 isr = readl(_ISR(i2c));
1006 if (!(isr & VALID_INT_SOURCE))
1007 return IRQ_NONE;
1009 if (i2c_debug > 2 && 0) {
1010 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
1011 __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
1012 decode_ISR(isr);
1015 if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
1016 i2c->isrlog[i2c->irqlogidx++] = isr;
1018 show_state(i2c);
1021 * Always clear all pending IRQs.
1023 writel(isr & VALID_INT_SOURCE, _ISR(i2c));
1025 if (isr & ISR_SAD)
1026 i2c_pxa_slave_start(i2c, isr);
1027 if (isr & ISR_SSD)
1028 i2c_pxa_slave_stop(i2c);
1030 if (i2c_pxa_is_slavemode(i2c)) {
1031 if (isr & ISR_ITE)
1032 i2c_pxa_slave_txempty(i2c, isr);
1033 if (isr & ISR_IRF)
1034 i2c_pxa_slave_rxfull(i2c, isr);
1035 } else if (i2c->msg && (!i2c->highmode_enter)) {
1036 if (isr & ISR_ITE)
1037 i2c_pxa_irq_txempty(i2c, isr);
1038 if (isr & ISR_IRF)
1039 i2c_pxa_irq_rxfull(i2c, isr);
1040 } else if ((isr & ISR_ITE) && i2c->highmode_enter) {
1041 i2c->highmode_enter = false;
1042 wake_up(&i2c->wait);
1043 } else {
1044 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
1047 return IRQ_HANDLED;
1051 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
1053 struct pxa_i2c *i2c = adap->algo_data;
1054 int ret, i;
1056 for (i = adap->retries; i >= 0; i--) {
1057 ret = i2c_pxa_do_xfer(i2c, msgs, num);
1058 if (ret != I2C_RETRY)
1059 goto out;
1061 if (i2c_debug)
1062 dev_dbg(&adap->dev, "Retrying transmission\n");
1063 udelay(100);
1065 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
1066 ret = -EREMOTEIO;
1067 out:
1068 i2c_pxa_set_slave(i2c, ret);
1069 return ret;
1072 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
1074 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
1077 static const struct i2c_algorithm i2c_pxa_algorithm = {
1078 .master_xfer = i2c_pxa_xfer,
1079 .functionality = i2c_pxa_functionality,
1082 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
1083 .master_xfer = i2c_pxa_pio_xfer,
1084 .functionality = i2c_pxa_functionality,
1087 static struct of_device_id i2c_pxa_dt_ids[] = {
1088 { .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX },
1089 { .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX },
1090 { .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA2XX },
1093 MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
1095 static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
1096 enum pxa_i2c_types *i2c_types)
1098 struct device_node *np = pdev->dev.of_node;
1099 const struct of_device_id *of_id =
1100 of_match_device(i2c_pxa_dt_ids, &pdev->dev);
1102 if (!of_id)
1103 return 1;
1105 /* For device tree we always use the dynamic or alias-assigned ID */
1106 i2c->adap.nr = -1;
1108 if (of_get_property(np, "mrvl,i2c-polling", NULL))
1109 i2c->use_pio = 1;
1110 if (of_get_property(np, "mrvl,i2c-fast-mode", NULL))
1111 i2c->fast_mode = 1;
1112 *i2c_types = (u32)(of_id->data);
1113 return 0;
1116 static int i2c_pxa_probe_pdata(struct platform_device *pdev,
1117 struct pxa_i2c *i2c,
1118 enum pxa_i2c_types *i2c_types)
1120 struct i2c_pxa_platform_data *plat = dev_get_platdata(&pdev->dev);
1121 const struct platform_device_id *id = platform_get_device_id(pdev);
1123 *i2c_types = id->driver_data;
1124 if (plat) {
1125 i2c->use_pio = plat->use_pio;
1126 i2c->fast_mode = plat->fast_mode;
1127 i2c->high_mode = plat->high_mode;
1128 i2c->master_code = plat->master_code;
1129 if (!i2c->master_code)
1130 i2c->master_code = 0xe;
1131 i2c->rate = plat->rate;
1133 return 0;
1136 static int i2c_pxa_probe(struct platform_device *dev)
1138 struct i2c_pxa_platform_data *plat = dev_get_platdata(&dev->dev);
1139 enum pxa_i2c_types i2c_type;
1140 struct pxa_i2c *i2c;
1141 struct resource *res = NULL;
1142 int ret, irq;
1144 i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
1145 if (!i2c) {
1146 ret = -ENOMEM;
1147 goto emalloc;
1150 /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
1151 i2c->adap.nr = dev->id;
1153 ret = i2c_pxa_probe_dt(dev, i2c, &i2c_type);
1154 if (ret > 0)
1155 ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
1156 if (ret < 0)
1157 goto eclk;
1159 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
1160 irq = platform_get_irq(dev, 0);
1161 if (res == NULL || irq < 0) {
1162 ret = -ENODEV;
1163 goto eclk;
1166 if (!request_mem_region(res->start, resource_size(res), res->name)) {
1167 ret = -ENOMEM;
1168 goto eclk;
1171 i2c->adap.owner = THIS_MODULE;
1172 i2c->adap.retries = 5;
1174 spin_lock_init(&i2c->lock);
1175 init_waitqueue_head(&i2c->wait);
1177 strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
1179 i2c->clk = clk_get(&dev->dev, NULL);
1180 if (IS_ERR(i2c->clk)) {
1181 ret = PTR_ERR(i2c->clk);
1182 goto eclk;
1185 i2c->reg_base = ioremap(res->start, resource_size(res));
1186 if (!i2c->reg_base) {
1187 ret = -EIO;
1188 goto eremap;
1191 i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
1192 i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr;
1193 i2c->reg_icr = i2c->reg_base + pxa_reg_layout[i2c_type].icr;
1194 i2c->reg_isr = i2c->reg_base + pxa_reg_layout[i2c_type].isr;
1195 if (i2c_type != REGS_CE4100)
1196 i2c->reg_isar = i2c->reg_base + pxa_reg_layout[i2c_type].isar;
1198 i2c->iobase = res->start;
1199 i2c->iosize = resource_size(res);
1201 i2c->irq = irq;
1203 i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1204 i2c->highmode_enter = false;
1206 if (plat) {
1207 #ifdef CONFIG_I2C_PXA_SLAVE
1208 i2c->slave_addr = plat->slave_addr;
1209 i2c->slave = plat->slave;
1210 #endif
1211 i2c->adap.class = plat->class;
1214 if (i2c->high_mode) {
1215 if (i2c->rate) {
1216 clk_set_rate(i2c->clk, i2c->rate);
1217 pr_info("i2c: <%s> set rate to %ld\n",
1218 i2c->adap.name, clk_get_rate(i2c->clk));
1219 } else
1220 pr_warn("i2c: <%s> clock rate not set\n",
1221 i2c->adap.name);
1224 clk_prepare_enable(i2c->clk);
1226 if (i2c->use_pio) {
1227 i2c->adap.algo = &i2c_pxa_pio_algorithm;
1228 } else {
1229 i2c->adap.algo = &i2c_pxa_algorithm;
1230 ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
1231 dev_name(&dev->dev), i2c);
1232 if (ret)
1233 goto ereqirq;
1236 i2c_pxa_reset(i2c);
1238 i2c->adap.algo_data = i2c;
1239 i2c->adap.dev.parent = &dev->dev;
1240 #ifdef CONFIG_OF
1241 i2c->adap.dev.of_node = dev->dev.of_node;
1242 #endif
1244 ret = i2c_add_numbered_adapter(&i2c->adap);
1245 if (ret < 0) {
1246 printk(KERN_INFO "I2C: Failed to add bus\n");
1247 goto eadapt;
1250 platform_set_drvdata(dev, i2c);
1252 #ifdef CONFIG_I2C_PXA_SLAVE
1253 printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
1254 dev_name(&i2c->adap.dev), i2c->slave_addr);
1255 #else
1256 printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
1257 dev_name(&i2c->adap.dev));
1258 #endif
1259 return 0;
1261 eadapt:
1262 if (!i2c->use_pio)
1263 free_irq(irq, i2c);
1264 ereqirq:
1265 clk_disable_unprepare(i2c->clk);
1266 iounmap(i2c->reg_base);
1267 eremap:
1268 clk_put(i2c->clk);
1269 eclk:
1270 kfree(i2c);
1271 emalloc:
1272 release_mem_region(res->start, resource_size(res));
1273 return ret;
1276 static int i2c_pxa_remove(struct platform_device *dev)
1278 struct pxa_i2c *i2c = platform_get_drvdata(dev);
1280 i2c_del_adapter(&i2c->adap);
1281 if (!i2c->use_pio)
1282 free_irq(i2c->irq, i2c);
1284 clk_disable_unprepare(i2c->clk);
1285 clk_put(i2c->clk);
1287 iounmap(i2c->reg_base);
1288 release_mem_region(i2c->iobase, i2c->iosize);
1289 kfree(i2c);
1291 return 0;
1294 #ifdef CONFIG_PM
1295 static int i2c_pxa_suspend_noirq(struct device *dev)
1297 struct platform_device *pdev = to_platform_device(dev);
1298 struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1300 clk_disable(i2c->clk);
1302 return 0;
1305 static int i2c_pxa_resume_noirq(struct device *dev)
1307 struct platform_device *pdev = to_platform_device(dev);
1308 struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1310 clk_enable(i2c->clk);
1311 i2c_pxa_reset(i2c);
1313 return 0;
1316 static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
1317 .suspend_noirq = i2c_pxa_suspend_noirq,
1318 .resume_noirq = i2c_pxa_resume_noirq,
1321 #define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
1322 #else
1323 #define I2C_PXA_DEV_PM_OPS NULL
1324 #endif
1326 static struct platform_driver i2c_pxa_driver = {
1327 .probe = i2c_pxa_probe,
1328 .remove = i2c_pxa_remove,
1329 .driver = {
1330 .name = "pxa2xx-i2c",
1331 .owner = THIS_MODULE,
1332 .pm = I2C_PXA_DEV_PM_OPS,
1333 .of_match_table = i2c_pxa_dt_ids,
1335 .id_table = i2c_pxa_id_table,
1338 static int __init i2c_adap_pxa_init(void)
1340 return platform_driver_register(&i2c_pxa_driver);
1343 static void __exit i2c_adap_pxa_exit(void)
1345 platform_driver_unregister(&i2c_pxa_driver);
1348 MODULE_LICENSE("GPL");
1349 MODULE_ALIAS("platform:pxa2xx-i2c");
1351 subsys_initcall(i2c_adap_pxa_init);
1352 module_exit(i2c_adap_pxa_exit);