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.
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>
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>
39 #include <linux/i2c/pxa-i2c.h>
43 struct pxa_reg_layout
{
58 * I2C registers definitions
60 static struct pxa_reg_layout pxa_reg_layout
[] = {
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
},
90 MODULE_DEVICE_TABLE(platform
, i2c_pxa_id_table
);
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 */
129 wait_queue_head_t wait
;
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
;
138 #ifdef CONFIG_I2C_PXA_SLAVE
139 struct i2c_slave_client
*slave
;
142 unsigned int irqlogidx
;
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
;
157 unsigned int use_pio
:1;
158 unsigned int fast_mode
:1;
159 unsigned int high_mode
:1;
160 unsigned char master_code
;
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
183 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
186 decode_bits(const char *prefix
, const struct bits
*bits
, int num
, u32 val
)
188 printk("%s %08x: ", prefix
, val
);
190 const char *str
= val
& bits
->mask
? bits
->set
: bits
->unset
;
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
);
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
);
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
)
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
]);
267 #else /* ifdef DEBUG */
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
)
290 if (i2c_pxa_is_slavemode(i2c
)) {
291 dev_dbg(&i2c
->adap
.dev
, "%s: called in slave mode\n", __func__
);
295 while ((i
> 0) && (readl(_IBMR(i2c
)) & 0x1) == 0) {
296 unsigned long icr
= readl(_ICR(i2c
));
299 icr
|= ICR_ACKNAK
| ICR_STOP
| ICR_TB
;
301 writel(icr
, _ICR(i2c
));
309 writel(readl(_ICR(i2c
)) & ~(ICR_MA
| ICR_START
| ICR_STOP
),
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)
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
)) {
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
) {
342 dev_dbg(&i2c
->adap
.dev
, "%s: Slave detected\n", __func__
);
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
350 if ((readl(_ISR(i2c
)) & (ISR_UB
| ISR_IBB
)) == 0 && readl(_IBMR(i2c
)) == 3) {
352 dev_dbg(&i2c
->adap
.dev
, "%s: done\n", __func__
);
360 dev_dbg(&i2c
->adap
.dev
, "%s: did not free\n", __func__
);
365 static int i2c_pxa_set_master(struct pxa_i2c
*i2c
)
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__
);
378 writel(readl(_ICR(i2c
)) | ICR_SCLE
, _ICR(i2c
));
382 #ifdef CONFIG_I2C_PXA_SLAVE
383 static int i2c_pxa_wait_slave(struct pxa_i2c
*i2c
)
385 unsigned long timeout
= jiffies
+ HZ
*1;
391 while (time_before(jiffies
, timeout
)) {
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) {
400 dev_dbg(&i2c
->adap
.dev
, "%s: done\n", __func__
);
408 dev_dbg(&i2c
->adap
.dev
, "%s: did not free\n", __func__
);
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
)
421 udelay(100); /* simple delay */
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
) {
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",
438 writel(readl(_ICR(i2c
)) & ~(ICR_STOP
|ICR_ACKNAK
|ICR_MA
), _ICR(i2c
));
439 writel(readl(_ICR(i2c
)) & ~ICR_SCLE
, _ICR(i2c
));
442 dev_dbg(&i2c
->adap
.dev
, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c
)), readl(_ISR(i2c
)));
443 decode_ICR(readl(_ICR(i2c
)));
447 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
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 */
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
));
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
));
474 i2c_pxa_set_slave(i2c
, 0);
477 writel(readl(_ICR(i2c
)) | ICR_IUE
, _ICR(i2c
));
482 #ifdef CONFIG_I2C_PXA_SLAVE
487 static void i2c_pxa_slave_txempty(struct pxa_i2c
*i2c
, u32 isr
)
490 /* what should we do here? */
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
)
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
));
535 if ((readl(_IBMR(i2c
)) & 2) == 2)
541 dev_err(&i2c
->adap
.dev
, "timeout waiting for SCL high\n");
546 writel(readl(_ICR(i2c
)) & ~ICR_SCLE
, _ICR(i2c
));
549 static void i2c_pxa_slave_stop(struct pxa_i2c
*i2c
)
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
);
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.
565 i2c_pxa_master_complete(i2c
, I2C_RETRY
);
568 static void i2c_pxa_slave_txempty(struct pxa_i2c
*i2c
, u32 isr
)
571 /* what should we do here? */
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
)
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
));
598 if ((readl(_IBMR(i2c
)) & 2) == 2)
604 dev_err(&i2c
->adap
.dev
, "timeout waiting for SCL high\n");
609 writel(readl(_ICR(i2c
)) & ~ICR_SCLE
, _ICR(i2c
));
612 static void i2c_pxa_slave_stop(struct pxa_i2c
*i2c
)
615 i2c_pxa_master_complete(i2c
, I2C_RETRY
);
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
)
633 static inline void i2c_pxa_start_message(struct pxa_i2c
*i2c
)
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
)
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
)) {
676 dev_err(&i2c
->adap
.dev
,
677 "i2c_pxa: timeout waiting for bus free\n");
684 writel(readl(_ICR(i2c
)) | ICR_SCLE
, _ICR(i2c
));
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
)
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 */
723 ret
= i2c_pxa_pio_set_master(i2c
);
733 i2c_pxa_start_message(i2c
);
735 while (i2c
->msg_num
> 0 && --timeout
) {
736 i2c_pxa_handler(0, i2c
);
740 i2c_pxa_stop_message(i2c
);
743 * We place the return code in i2c->msg_idx.
749 i2c_pxa_scream_blue_murder(i2c
, "timeout");
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
)
763 * Wait for the bus to become free.
765 ret
= i2c_pxa_wait_bus_not_busy(i2c
);
767 dev_err(&i2c
->adap
.dev
, "i2c_pxa: timeout waiting for bus free\n");
774 ret
= i2c_pxa_set_master(i2c
);
776 dev_err(&i2c
->adap
.dev
, "i2c_pxa_set_master: error %d\n", ret
);
780 if (i2c
->high_mode
) {
781 ret
= i2c_pxa_send_mastercode(i2c
);
783 dev_err(&i2c
->adap
.dev
, "i2c_pxa_send_mastercode timeout\n");
788 spin_lock_irq(&i2c
->lock
);
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.
811 if (!timeout
&& i2c
->msg_num
) {
812 i2c_pxa_scream_blue_murder(i2c
, "timeout");
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
;
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
))
833 for (i
= adap
->retries
; i
>= 0; i
--) {
834 ret
= i2c_pxa_do_pio_xfer(i2c
, msgs
, num
);
835 if (ret
!= I2C_RETRY
)
839 dev_dbg(&adap
->dev
, "Retrying transmission\n");
842 i2c_pxa_scream_blue_murder(i2c
, "exhausted retries");
845 i2c_pxa_set_slave(i2c
, 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
)
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
);
870 * If ISR_ALD is set, we lost arbitration.
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.
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)
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
925 if (i2c
->msg_ptr
== i2c
->msg
->len
&&
926 i2c
->msg_idx
== i2c
->msg_num
- 1)
928 } else if (i2c
->msg_idx
< i2c
->msg_num
- 1) {
930 * Next segment of the message.
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
)
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.
953 icr
|= ICR_START
| ICR_TB
;
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
963 i2c_pxa_master_complete(i2c
, 0);
966 i2c
->icrlog
[i2c
->irqlogidx
-1] = icr
;
968 writel(icr
, _ICR(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
);
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
;
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 | \
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
))
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
)));
1015 if (i2c
->irqlogidx
< ARRAY_SIZE(i2c
->isrlog
))
1016 i2c
->isrlog
[i2c
->irqlogidx
++] = isr
;
1021 * Always clear all pending IRQs.
1023 writel(isr
& VALID_INT_SOURCE
, _ISR(i2c
));
1026 i2c_pxa_slave_start(i2c
, isr
);
1028 i2c_pxa_slave_stop(i2c
);
1030 if (i2c_pxa_is_slavemode(i2c
)) {
1032 i2c_pxa_slave_txempty(i2c
, isr
);
1034 i2c_pxa_slave_rxfull(i2c
, isr
);
1035 } else if (i2c
->msg
&& (!i2c
->highmode_enter
)) {
1037 i2c_pxa_irq_txempty(i2c
, isr
);
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
);
1044 i2c_pxa_scream_blue_murder(i2c
, "spurious irq");
1051 static int i2c_pxa_xfer(struct i2c_adapter
*adap
, struct i2c_msg msgs
[], int num
)
1053 struct pxa_i2c
*i2c
= adap
->algo_data
;
1056 for (i
= adap
->retries
; i
>= 0; i
--) {
1057 ret
= i2c_pxa_do_xfer(i2c
, msgs
, num
);
1058 if (ret
!= I2C_RETRY
)
1062 dev_dbg(&adap
->dev
, "Retrying transmission\n");
1065 i2c_pxa_scream_blue_murder(i2c
, "exhausted retries");
1068 i2c_pxa_set_slave(i2c
, 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
);
1105 /* For device tree we always use the dynamic or alias-assigned ID */
1108 if (of_get_property(np
, "mrvl,i2c-polling", NULL
))
1110 if (of_get_property(np
, "mrvl,i2c-fast-mode", NULL
))
1112 *i2c_types
= (u32
)(of_id
->data
);
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
;
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
;
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
;
1144 i2c
= kzalloc(sizeof(struct pxa_i2c
), GFP_KERNEL
);
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
);
1155 ret
= i2c_pxa_probe_pdata(dev
, i2c
, &i2c_type
);
1159 res
= platform_get_resource(dev
, IORESOURCE_MEM
, 0);
1160 irq
= platform_get_irq(dev
, 0);
1161 if (res
== NULL
|| irq
< 0) {
1166 if (!request_mem_region(res
->start
, resource_size(res
), res
->name
)) {
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
);
1185 i2c
->reg_base
= ioremap(res
->start
, resource_size(res
));
1186 if (!i2c
->reg_base
) {
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
);
1203 i2c
->slave_addr
= I2C_PXA_SLAVE_ADDR
;
1204 i2c
->highmode_enter
= false;
1207 #ifdef CONFIG_I2C_PXA_SLAVE
1208 i2c
->slave_addr
= plat
->slave_addr
;
1209 i2c
->slave
= plat
->slave
;
1211 i2c
->adap
.class = plat
->class;
1214 if (i2c
->high_mode
) {
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
));
1220 pr_warn("i2c: <%s> clock rate not set\n",
1224 clk_prepare_enable(i2c
->clk
);
1227 i2c
->adap
.algo
= &i2c_pxa_pio_algorithm
;
1229 i2c
->adap
.algo
= &i2c_pxa_algorithm
;
1230 ret
= request_irq(irq
, i2c_pxa_handler
, IRQF_SHARED
,
1231 dev_name(&dev
->dev
), i2c
);
1238 i2c
->adap
.algo_data
= i2c
;
1239 i2c
->adap
.dev
.parent
= &dev
->dev
;
1241 i2c
->adap
.dev
.of_node
= dev
->dev
.of_node
;
1244 ret
= i2c_add_numbered_adapter(&i2c
->adap
);
1246 printk(KERN_INFO
"I2C: Failed to add bus\n");
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
);
1256 printk(KERN_INFO
"I2C: %s: PXA I2C adapter\n",
1257 dev_name(&i2c
->adap
.dev
));
1265 clk_disable_unprepare(i2c
->clk
);
1266 iounmap(i2c
->reg_base
);
1272 release_mem_region(res
->start
, resource_size(res
));
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
);
1282 free_irq(i2c
->irq
, i2c
);
1284 clk_disable_unprepare(i2c
->clk
);
1287 iounmap(i2c
->reg_base
);
1288 release_mem_region(i2c
->iobase
, i2c
->iosize
);
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
);
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
);
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)
1323 #define I2C_PXA_DEV_PM_OPS NULL
1326 static struct platform_driver i2c_pxa_driver
= {
1327 .probe
= i2c_pxa_probe
,
1328 .remove
= i2c_pxa_remove
,
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
);