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/platform_data/i2c-pxa.h>
43 struct pxa_reg_layout
{
63 #define ICR_BUSMODE_FM (1 << 16) /* shifted fast mode for armada-3700 */
64 #define ICR_BUSMODE_HS (1 << 17) /* shifted high speed mode for armada-3700 */
67 * I2C registers definitions
69 static struct pxa_reg_layout pxa_reg_layout
[] = {
89 /* no isar register */
106 .fm
= ICR_BUSMODE_FM
,
107 .hs
= ICR_BUSMODE_HS
,
111 static const struct platform_device_id i2c_pxa_id_table
[] = {
112 { "pxa2xx-i2c", REGS_PXA2XX
},
113 { "pxa3xx-pwri2c", REGS_PXA3XX
},
114 { "ce4100-i2c", REGS_CE4100
},
115 { "pxa910-i2c", REGS_PXA910
},
116 { "armada-3700-i2c", REGS_A3700
},
119 MODULE_DEVICE_TABLE(platform
, i2c_pxa_id_table
);
122 * I2C bit definitions
125 #define ICR_START (1 << 0) /* start bit */
126 #define ICR_STOP (1 << 1) /* stop bit */
127 #define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
128 #define ICR_TB (1 << 3) /* transfer byte bit */
129 #define ICR_MA (1 << 4) /* master abort */
130 #define ICR_SCLE (1 << 5) /* master clock enable */
131 #define ICR_IUE (1 << 6) /* unit enable */
132 #define ICR_GCD (1 << 7) /* general call disable */
133 #define ICR_ITEIE (1 << 8) /* enable tx interrupts */
134 #define ICR_IRFIE (1 << 9) /* enable rx interrupts */
135 #define ICR_BEIE (1 << 10) /* enable bus error ints */
136 #define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
137 #define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
138 #define ICR_SADIE (1 << 13) /* slave address detected int enable */
139 #define ICR_UR (1 << 14) /* unit reset */
140 #define ICR_FM (1 << 15) /* fast mode */
141 #define ICR_HS (1 << 16) /* High Speed mode */
142 #define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */
144 #define ISR_RWM (1 << 0) /* read/write mode */
145 #define ISR_ACKNAK (1 << 1) /* ack/nak status */
146 #define ISR_UB (1 << 2) /* unit busy */
147 #define ISR_IBB (1 << 3) /* bus busy */
148 #define ISR_SSD (1 << 4) /* slave stop detected */
149 #define ISR_ALD (1 << 5) /* arbitration loss detected */
150 #define ISR_ITE (1 << 6) /* tx buffer empty */
151 #define ISR_IRF (1 << 7) /* rx buffer full */
152 #define ISR_GCAD (1 << 8) /* general call address detected */
153 #define ISR_SAD (1 << 9) /* slave address detected */
154 #define ISR_BED (1 << 10) /* bus error no ACK/NAK */
156 /* bit field shift & mask */
157 #define ILCR_SLV_SHIFT 0
158 #define ILCR_SLV_MASK (0x1FF << ILCR_SLV_SHIFT)
159 #define ILCR_FLV_SHIFT 9
160 #define ILCR_FLV_MASK (0x1FF << ILCR_FLV_SHIFT)
161 #define ILCR_HLVL_SHIFT 18
162 #define ILCR_HLVL_MASK (0x1FF << ILCR_HLVL_SHIFT)
163 #define ILCR_HLVH_SHIFT 27
164 #define ILCR_HLVH_MASK (0x1F << ILCR_HLVH_SHIFT)
166 #define IWCR_CNT_SHIFT 0
167 #define IWCR_CNT_MASK (0x1F << IWCR_CNT_SHIFT)
168 #define IWCR_HS_CNT1_SHIFT 5
169 #define IWCR_HS_CNT1_MASK (0x1F << IWCR_HS_CNT1_SHIFT)
170 #define IWCR_HS_CNT2_SHIFT 10
171 #define IWCR_HS_CNT2_MASK (0x1F << IWCR_HS_CNT2_SHIFT)
175 wait_queue_head_t wait
;
177 unsigned int msg_num
;
178 unsigned int msg_idx
;
179 unsigned int msg_ptr
;
180 unsigned int slave_addr
;
181 unsigned int req_slave_addr
;
183 struct i2c_adapter adap
;
185 #ifdef CONFIG_I2C_PXA_SLAVE
186 struct i2c_slave_client
*slave
;
189 unsigned int irqlogidx
;
193 void __iomem
*reg_base
;
194 void __iomem
*reg_ibmr
;
195 void __iomem
*reg_idbr
;
196 void __iomem
*reg_icr
;
197 void __iomem
*reg_isr
;
198 void __iomem
*reg_isar
;
199 void __iomem
*reg_ilcr
;
200 void __iomem
*reg_iwcr
;
202 unsigned long iobase
;
203 unsigned long iosize
;
206 unsigned int use_pio
:1;
207 unsigned int fast_mode
:1;
208 unsigned int high_mode
:1;
209 unsigned char master_code
;
216 #define _IBMR(i2c) ((i2c)->reg_ibmr)
217 #define _IDBR(i2c) ((i2c)->reg_idbr)
218 #define _ICR(i2c) ((i2c)->reg_icr)
219 #define _ISR(i2c) ((i2c)->reg_isr)
220 #define _ISAR(i2c) ((i2c)->reg_isar)
221 #define _ILCR(i2c) ((i2c)->reg_ilcr)
222 #define _IWCR(i2c) ((i2c)->reg_iwcr)
225 * I2C Slave mode address
227 #define I2C_PXA_SLAVE_ADDR 0x1
236 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
239 decode_bits(const char *prefix
, const struct bits
*bits
, int num
, u32 val
)
241 printk("%s %08x: ", prefix
, val
);
243 const char *str
= val
& bits
->mask
? bits
->set
: bits
->unset
;
250 static const struct bits isr_bits
[] = {
251 PXA_BIT(ISR_RWM
, "RX", "TX"),
252 PXA_BIT(ISR_ACKNAK
, "NAK", "ACK"),
253 PXA_BIT(ISR_UB
, "Bsy", "Rdy"),
254 PXA_BIT(ISR_IBB
, "BusBsy", "BusRdy"),
255 PXA_BIT(ISR_SSD
, "SlaveStop", NULL
),
256 PXA_BIT(ISR_ALD
, "ALD", NULL
),
257 PXA_BIT(ISR_ITE
, "TxEmpty", NULL
),
258 PXA_BIT(ISR_IRF
, "RxFull", NULL
),
259 PXA_BIT(ISR_GCAD
, "GenCall", NULL
),
260 PXA_BIT(ISR_SAD
, "SlaveAddr", NULL
),
261 PXA_BIT(ISR_BED
, "BusErr", NULL
),
264 static void decode_ISR(unsigned int val
)
266 decode_bits(KERN_DEBUG
"ISR", isr_bits
, ARRAY_SIZE(isr_bits
), val
);
270 static const struct bits icr_bits
[] = {
271 PXA_BIT(ICR_START
, "START", NULL
),
272 PXA_BIT(ICR_STOP
, "STOP", NULL
),
273 PXA_BIT(ICR_ACKNAK
, "ACKNAK", NULL
),
274 PXA_BIT(ICR_TB
, "TB", NULL
),
275 PXA_BIT(ICR_MA
, "MA", NULL
),
276 PXA_BIT(ICR_SCLE
, "SCLE", "scle"),
277 PXA_BIT(ICR_IUE
, "IUE", "iue"),
278 PXA_BIT(ICR_GCD
, "GCD", NULL
),
279 PXA_BIT(ICR_ITEIE
, "ITEIE", NULL
),
280 PXA_BIT(ICR_IRFIE
, "IRFIE", NULL
),
281 PXA_BIT(ICR_BEIE
, "BEIE", NULL
),
282 PXA_BIT(ICR_SSDIE
, "SSDIE", NULL
),
283 PXA_BIT(ICR_ALDIE
, "ALDIE", NULL
),
284 PXA_BIT(ICR_SADIE
, "SADIE", NULL
),
285 PXA_BIT(ICR_UR
, "UR", "ur"),
288 #ifdef CONFIG_I2C_PXA_SLAVE
289 static void decode_ICR(unsigned int val
)
291 decode_bits(KERN_DEBUG
"ICR", icr_bits
, ARRAY_SIZE(icr_bits
), val
);
296 static unsigned int i2c_debug
= DEBUG
;
298 static void i2c_pxa_show_state(struct pxa_i2c
*i2c
, int lno
, const char *fname
)
300 dev_dbg(&i2c
->adap
.dev
, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname
, lno
,
301 readl(_ISR(i2c
)), readl(_ICR(i2c
)), readl(_IBMR(i2c
)));
304 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
306 static void i2c_pxa_scream_blue_murder(struct pxa_i2c
*i2c
, const char *why
)
309 struct device
*dev
= &i2c
->adap
.dev
;
311 dev_err(dev
, "slave_0x%x error: %s\n",
312 i2c
->req_slave_addr
>> 1, why
);
313 dev_err(dev
, "msg_num: %d msg_idx: %d msg_ptr: %d\n",
314 i2c
->msg_num
, i2c
->msg_idx
, i2c
->msg_ptr
);
315 dev_err(dev
, "IBMR: %08x IDBR: %08x ICR: %08x ISR: %08x\n",
316 readl(_IBMR(i2c
)), readl(_IDBR(i2c
)), readl(_ICR(i2c
)),
318 dev_dbg(dev
, "log: ");
319 for (i
= 0; i
< i2c
->irqlogidx
; i
++)
320 pr_debug("[%08x:%08x] ", i2c
->isrlog
[i
], i2c
->icrlog
[i
]);
325 #else /* ifdef DEBUG */
329 #define show_state(i2c) do { } while (0)
330 #define decode_ISR(val) do { } while (0)
331 #define decode_ICR(val) do { } while (0)
332 #define i2c_pxa_scream_blue_murder(i2c, why) do { } while (0)
334 #endif /* ifdef DEBUG / else */
336 static void i2c_pxa_master_complete(struct pxa_i2c
*i2c
, int ret
);
337 static irqreturn_t
i2c_pxa_handler(int this_irq
, void *dev_id
);
339 static inline int i2c_pxa_is_slavemode(struct pxa_i2c
*i2c
)
341 return !(readl(_ICR(i2c
)) & ICR_SCLE
);
344 static void i2c_pxa_abort(struct pxa_i2c
*i2c
)
348 if (i2c_pxa_is_slavemode(i2c
)) {
349 dev_dbg(&i2c
->adap
.dev
, "%s: called in slave mode\n", __func__
);
353 while ((i
> 0) && (readl(_IBMR(i2c
)) & 0x1) == 0) {
354 unsigned long icr
= readl(_ICR(i2c
));
357 icr
|= ICR_ACKNAK
| ICR_STOP
| ICR_TB
;
359 writel(icr
, _ICR(i2c
));
367 writel(readl(_ICR(i2c
)) & ~(ICR_MA
| ICR_START
| ICR_STOP
),
371 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c
*i2c
)
373 int timeout
= DEF_TIMEOUT
;
375 while (timeout
-- && readl(_ISR(i2c
)) & (ISR_IBB
| ISR_UB
)) {
376 if ((readl(_ISR(i2c
)) & ISR_SAD
) != 0)
386 return timeout
< 0 ? I2C_RETRY
: 0;
389 static int i2c_pxa_wait_master(struct pxa_i2c
*i2c
)
391 unsigned long timeout
= jiffies
+ HZ
*4;
393 while (time_before(jiffies
, timeout
)) {
395 dev_dbg(&i2c
->adap
.dev
, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
396 __func__
, (long)jiffies
, readl(_ISR(i2c
)), readl(_ICR(i2c
)), readl(_IBMR(i2c
)));
398 if (readl(_ISR(i2c
)) & ISR_SAD
) {
400 dev_dbg(&i2c
->adap
.dev
, "%s: Slave detected\n", __func__
);
404 /* wait for unit and bus being not busy, and we also do a
405 * quick check of the i2c lines themselves to ensure they've
408 if ((readl(_ISR(i2c
)) & (ISR_UB
| ISR_IBB
)) == 0 && readl(_IBMR(i2c
)) == 3) {
410 dev_dbg(&i2c
->adap
.dev
, "%s: done\n", __func__
);
418 dev_dbg(&i2c
->adap
.dev
, "%s: did not free\n", __func__
);
423 static int i2c_pxa_set_master(struct pxa_i2c
*i2c
)
426 dev_dbg(&i2c
->adap
.dev
, "setting to bus master\n");
428 if ((readl(_ISR(i2c
)) & (ISR_UB
| ISR_IBB
)) != 0) {
429 dev_dbg(&i2c
->adap
.dev
, "%s: unit is busy\n", __func__
);
430 if (!i2c_pxa_wait_master(i2c
)) {
431 dev_dbg(&i2c
->adap
.dev
, "%s: error: unit busy\n", __func__
);
436 writel(readl(_ICR(i2c
)) | ICR_SCLE
, _ICR(i2c
));
440 #ifdef CONFIG_I2C_PXA_SLAVE
441 static int i2c_pxa_wait_slave(struct pxa_i2c
*i2c
)
443 unsigned long timeout
= jiffies
+ HZ
*1;
449 while (time_before(jiffies
, timeout
)) {
451 dev_dbg(&i2c
->adap
.dev
, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
452 __func__
, (long)jiffies
, readl(_ISR(i2c
)), readl(_ICR(i2c
)), readl(_IBMR(i2c
)));
454 if ((readl(_ISR(i2c
)) & (ISR_UB
|ISR_IBB
)) == 0 ||
455 (readl(_ISR(i2c
)) & ISR_SAD
) != 0 ||
456 (readl(_ICR(i2c
)) & ICR_SCLE
) == 0) {
458 dev_dbg(&i2c
->adap
.dev
, "%s: done\n", __func__
);
466 dev_dbg(&i2c
->adap
.dev
, "%s: did not free\n", __func__
);
471 * clear the hold on the bus, and take of anything else
472 * that has been configured
474 static void i2c_pxa_set_slave(struct pxa_i2c
*i2c
, int errcode
)
479 udelay(100); /* simple delay */
481 /* we need to wait for the stop condition to end */
483 /* if we where in stop, then clear... */
484 if (readl(_ICR(i2c
)) & ICR_STOP
) {
486 writel(readl(_ICR(i2c
)) & ~ICR_STOP
, _ICR(i2c
));
489 if (!i2c_pxa_wait_slave(i2c
)) {
490 dev_err(&i2c
->adap
.dev
, "%s: wait timedout\n",
496 writel(readl(_ICR(i2c
)) & ~(ICR_STOP
|ICR_ACKNAK
|ICR_MA
), _ICR(i2c
));
497 writel(readl(_ICR(i2c
)) & ~ICR_SCLE
, _ICR(i2c
));
500 dev_dbg(&i2c
->adap
.dev
, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c
)), readl(_ISR(i2c
)));
501 decode_ICR(readl(_ICR(i2c
)));
505 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
508 static void i2c_pxa_reset(struct pxa_i2c
*i2c
)
510 pr_debug("Resetting I2C Controller Unit\n");
512 /* abort any transfer currently under way */
515 /* reset according to 9.8 */
516 writel(ICR_UR
, _ICR(i2c
));
517 writel(I2C_ISR_INIT
, _ISR(i2c
));
518 writel(readl(_ICR(i2c
)) & ~ICR_UR
, _ICR(i2c
));
520 if (i2c
->reg_isar
&& IS_ENABLED(CONFIG_I2C_PXA_SLAVE
))
521 writel(i2c
->slave_addr
, _ISAR(i2c
));
523 /* set control register values */
524 writel(I2C_ICR_INIT
| (i2c
->fast_mode
? i2c
->fm_mask
: 0), _ICR(i2c
));
525 writel(readl(_ICR(i2c
)) | (i2c
->high_mode
? i2c
->hs_mask
: 0), _ICR(i2c
));
527 #ifdef CONFIG_I2C_PXA_SLAVE
528 dev_info(&i2c
->adap
.dev
, "Enabling slave mode\n");
529 writel(readl(_ICR(i2c
)) | ICR_SADIE
| ICR_ALDIE
| ICR_SSDIE
, _ICR(i2c
));
532 i2c_pxa_set_slave(i2c
, 0);
535 writel(readl(_ICR(i2c
)) | ICR_IUE
, _ICR(i2c
));
540 #ifdef CONFIG_I2C_PXA_SLAVE
545 static void i2c_pxa_slave_txempty(struct pxa_i2c
*i2c
, u32 isr
)
548 /* what should we do here? */
552 if (i2c
->slave
!= NULL
)
553 ret
= i2c
->slave
->read(i2c
->slave
->data
);
555 writel(ret
, _IDBR(i2c
));
556 writel(readl(_ICR(i2c
)) | ICR_TB
, _ICR(i2c
)); /* allow next byte */
560 static void i2c_pxa_slave_rxfull(struct pxa_i2c
*i2c
, u32 isr
)
562 unsigned int byte
= readl(_IDBR(i2c
));
564 if (i2c
->slave
!= NULL
)
565 i2c
->slave
->write(i2c
->slave
->data
, byte
);
567 writel(readl(_ICR(i2c
)) | ICR_TB
, _ICR(i2c
));
570 static void i2c_pxa_slave_start(struct pxa_i2c
*i2c
, u32 isr
)
575 dev_dbg(&i2c
->adap
.dev
, "SAD, mode is slave-%cx\n",
576 (isr
& ISR_RWM
) ? 'r' : 't');
578 if (i2c
->slave
!= NULL
)
579 i2c
->slave
->event(i2c
->slave
->data
,
580 (isr
& ISR_RWM
) ? I2C_SLAVE_EVENT_START_READ
: I2C_SLAVE_EVENT_START_WRITE
);
583 * slave could interrupt in the middle of us generating a
584 * start condition... if this happens, we'd better back off
585 * and stop holding the poor thing up
587 writel(readl(_ICR(i2c
)) & ~(ICR_START
|ICR_STOP
), _ICR(i2c
));
588 writel(readl(_ICR(i2c
)) | ICR_TB
, _ICR(i2c
));
593 if ((readl(_IBMR(i2c
)) & 2) == 2)
599 dev_err(&i2c
->adap
.dev
, "timeout waiting for SCL high\n");
604 writel(readl(_ICR(i2c
)) & ~ICR_SCLE
, _ICR(i2c
));
607 static void i2c_pxa_slave_stop(struct pxa_i2c
*i2c
)
610 dev_dbg(&i2c
->adap
.dev
, "ISR: SSD (Slave Stop)\n");
612 if (i2c
->slave
!= NULL
)
613 i2c
->slave
->event(i2c
->slave
->data
, I2C_SLAVE_EVENT_STOP
);
616 dev_dbg(&i2c
->adap
.dev
, "ISR: SSD (Slave Stop) acked\n");
619 * If we have a master-mode message waiting,
620 * kick it off now that the slave has completed.
623 i2c_pxa_master_complete(i2c
, I2C_RETRY
);
626 static void i2c_pxa_slave_txempty(struct pxa_i2c
*i2c
, u32 isr
)
629 /* what should we do here? */
631 writel(0, _IDBR(i2c
));
632 writel(readl(_ICR(i2c
)) | ICR_TB
, _ICR(i2c
));
636 static void i2c_pxa_slave_rxfull(struct pxa_i2c
*i2c
, u32 isr
)
638 writel(readl(_ICR(i2c
)) | ICR_TB
| ICR_ACKNAK
, _ICR(i2c
));
641 static void i2c_pxa_slave_start(struct pxa_i2c
*i2c
, u32 isr
)
646 * slave could interrupt in the middle of us generating a
647 * start condition... if this happens, we'd better back off
648 * and stop holding the poor thing up
650 writel(readl(_ICR(i2c
)) & ~(ICR_START
|ICR_STOP
), _ICR(i2c
));
651 writel(readl(_ICR(i2c
)) | ICR_TB
| ICR_ACKNAK
, _ICR(i2c
));
656 if ((readl(_IBMR(i2c
)) & 2) == 2)
662 dev_err(&i2c
->adap
.dev
, "timeout waiting for SCL high\n");
667 writel(readl(_ICR(i2c
)) & ~ICR_SCLE
, _ICR(i2c
));
670 static void i2c_pxa_slave_stop(struct pxa_i2c
*i2c
)
673 i2c_pxa_master_complete(i2c
, I2C_RETRY
);
678 * PXA I2C Master mode
681 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg
*msg
)
683 unsigned int addr
= (msg
->addr
& 0x7f) << 1;
685 if (msg
->flags
& I2C_M_RD
)
691 static inline void i2c_pxa_start_message(struct pxa_i2c
*i2c
)
696 * Step 1: target slave address into IDBR
698 writel(i2c_pxa_addr_byte(i2c
->msg
), _IDBR(i2c
));
699 i2c
->req_slave_addr
= i2c_pxa_addr_byte(i2c
->msg
);
702 * Step 2: initiate the write.
704 icr
= readl(_ICR(i2c
)) & ~(ICR_STOP
| ICR_ALDIE
);
705 writel(icr
| ICR_START
| ICR_TB
, _ICR(i2c
));
708 static inline void i2c_pxa_stop_message(struct pxa_i2c
*i2c
)
713 * Clear the STOP and ACK flags
715 icr
= readl(_ICR(i2c
));
716 icr
&= ~(ICR_STOP
| ICR_ACKNAK
);
717 writel(icr
, _ICR(i2c
));
720 static int i2c_pxa_pio_set_master(struct pxa_i2c
*i2c
)
722 /* make timeout the same as for interrupt based functions */
723 long timeout
= 2 * DEF_TIMEOUT
;
726 * Wait for the bus to become free.
728 while (timeout
-- && readl(_ISR(i2c
)) & (ISR_IBB
| ISR_UB
)) {
735 dev_err(&i2c
->adap
.dev
,
736 "i2c_pxa: timeout waiting for bus free\n");
743 writel(readl(_ICR(i2c
)) | ICR_SCLE
, _ICR(i2c
));
749 * PXA I2C send master code
750 * 1. Load master code to IDBR and send it.
751 * Note for HS mode, set ICR [GPIOEN].
752 * 2. Wait until win arbitration.
754 static int i2c_pxa_send_mastercode(struct pxa_i2c
*i2c
)
759 spin_lock_irq(&i2c
->lock
);
760 i2c
->highmode_enter
= true;
761 writel(i2c
->master_code
, _IDBR(i2c
));
763 icr
= readl(_ICR(i2c
)) & ~(ICR_STOP
| ICR_ALDIE
);
764 icr
|= ICR_GPIOEN
| ICR_START
| ICR_TB
| ICR_ITEIE
;
765 writel(icr
, _ICR(i2c
));
767 spin_unlock_irq(&i2c
->lock
);
768 timeout
= wait_event_timeout(i2c
->wait
,
769 i2c
->highmode_enter
== false, HZ
* 1);
771 i2c
->highmode_enter
= false;
773 return (timeout
== 0) ? I2C_RETRY
: 0;
776 static int i2c_pxa_do_pio_xfer(struct pxa_i2c
*i2c
,
777 struct i2c_msg
*msg
, int num
)
779 unsigned long timeout
= 500000; /* 5 seconds */
782 ret
= i2c_pxa_pio_set_master(i2c
);
792 i2c_pxa_start_message(i2c
);
794 while (i2c
->msg_num
> 0 && --timeout
) {
795 i2c_pxa_handler(0, i2c
);
799 i2c_pxa_stop_message(i2c
);
802 * We place the return code in i2c->msg_idx.
808 i2c_pxa_scream_blue_murder(i2c
, "timeout");
816 * We are protected by the adapter bus mutex.
818 static int i2c_pxa_do_xfer(struct pxa_i2c
*i2c
, struct i2c_msg
*msg
, int num
)
824 * Wait for the bus to become free.
826 ret
= i2c_pxa_wait_bus_not_busy(i2c
);
828 dev_err(&i2c
->adap
.dev
, "i2c_pxa: timeout waiting for bus free\n");
835 ret
= i2c_pxa_set_master(i2c
);
837 dev_err(&i2c
->adap
.dev
, "i2c_pxa_set_master: error %d\n", ret
);
841 if (i2c
->high_mode
) {
842 ret
= i2c_pxa_send_mastercode(i2c
);
844 dev_err(&i2c
->adap
.dev
, "i2c_pxa_send_mastercode timeout\n");
849 spin_lock_irq(&i2c
->lock
);
857 i2c_pxa_start_message(i2c
);
859 spin_unlock_irq(&i2c
->lock
);
862 * The rest of the processing occurs in the interrupt handler.
864 timeout
= wait_event_timeout(i2c
->wait
, i2c
->msg_num
== 0, HZ
* 5);
865 i2c_pxa_stop_message(i2c
);
868 * We place the return code in i2c->msg_idx.
872 if (!timeout
&& i2c
->msg_num
) {
873 i2c_pxa_scream_blue_murder(i2c
, "timeout");
881 static int i2c_pxa_pio_xfer(struct i2c_adapter
*adap
,
882 struct i2c_msg msgs
[], int num
)
884 struct pxa_i2c
*i2c
= adap
->algo_data
;
887 /* If the I2C controller is disabled we need to reset it
888 (probably due to a suspend/resume destroying state). We do
889 this here as we can then avoid worrying about resuming the
890 controller before its users. */
891 if (!(readl(_ICR(i2c
)) & ICR_IUE
))
894 for (i
= adap
->retries
; i
>= 0; i
--) {
895 ret
= i2c_pxa_do_pio_xfer(i2c
, msgs
, num
);
896 if (ret
!= I2C_RETRY
)
900 dev_dbg(&adap
->dev
, "Retrying transmission\n");
903 i2c_pxa_scream_blue_murder(i2c
, "exhausted retries");
906 i2c_pxa_set_slave(i2c
, ret
);
911 * i2c_pxa_master_complete - complete the message and wake up.
913 static void i2c_pxa_master_complete(struct pxa_i2c
*i2c
, int ret
)
925 static void i2c_pxa_irq_txempty(struct pxa_i2c
*i2c
, u32 isr
)
927 u32 icr
= readl(_ICR(i2c
)) & ~(ICR_START
|ICR_STOP
|ICR_ACKNAK
|ICR_TB
);
931 * If ISR_ALD is set, we lost arbitration.
935 * Do we need to do anything here? The PXA docs
936 * are vague about what happens.
938 i2c_pxa_scream_blue_murder(i2c
, "ALD set");
941 * We ignore this error. We seem to see spurious ALDs
942 * for seemingly no reason. If we handle them as I think
943 * they should, we end up causing an I2C error, which
944 * is painful for some systems.
949 if ((isr
& ISR_BED
) &&
950 (!((i2c
->msg
->flags
& I2C_M_IGNORE_NAK
) &&
951 (isr
& ISR_ACKNAK
)))) {
955 * I2C bus error - either the device NAK'd us, or
956 * something more serious happened. If we were NAK'd
957 * on the initial address phase, we can retry.
959 if (isr
& ISR_ACKNAK
) {
960 if (i2c
->msg_ptr
== 0 && i2c
->msg_idx
== 0)
965 i2c_pxa_master_complete(i2c
, ret
);
966 } else if (isr
& ISR_RWM
) {
968 * Read mode. We have just sent the address byte, and
969 * now we must initiate the transfer.
971 if (i2c
->msg_ptr
== i2c
->msg
->len
- 1 &&
972 i2c
->msg_idx
== i2c
->msg_num
- 1)
973 icr
|= ICR_STOP
| ICR_ACKNAK
;
975 icr
|= ICR_ALDIE
| ICR_TB
;
976 } else if (i2c
->msg_ptr
< i2c
->msg
->len
) {
978 * Write mode. Write the next data byte.
980 writel(i2c
->msg
->buf
[i2c
->msg_ptr
++], _IDBR(i2c
));
982 icr
|= ICR_ALDIE
| ICR_TB
;
985 * If this is the last byte of the last message or last byte
986 * of any message with I2C_M_STOP (e.g. SCCB), send a STOP.
988 if ((i2c
->msg_ptr
== i2c
->msg
->len
) &&
989 ((i2c
->msg
->flags
& I2C_M_STOP
) ||
990 (i2c
->msg_idx
== i2c
->msg_num
- 1)))
993 } else if (i2c
->msg_idx
< i2c
->msg_num
- 1) {
995 * Next segment of the message.
1002 * If we aren't doing a repeated start and address,
1003 * go back and try to send the next byte. Note that
1004 * we do not support switching the R/W direction here.
1006 if (i2c
->msg
->flags
& I2C_M_NOSTART
)
1010 * Write the next address.
1012 writel(i2c_pxa_addr_byte(i2c
->msg
), _IDBR(i2c
));
1013 i2c
->req_slave_addr
= i2c_pxa_addr_byte(i2c
->msg
);
1016 * And trigger a repeated start, and send the byte.
1019 icr
|= ICR_START
| ICR_TB
;
1021 if (i2c
->msg
->len
== 0) {
1023 * Device probes have a message length of zero
1024 * and need the bus to be reset before it can
1029 i2c_pxa_master_complete(i2c
, 0);
1032 i2c
->icrlog
[i2c
->irqlogidx
-1] = icr
;
1034 writel(icr
, _ICR(i2c
));
1038 static void i2c_pxa_irq_rxfull(struct pxa_i2c
*i2c
, u32 isr
)
1040 u32 icr
= readl(_ICR(i2c
)) & ~(ICR_START
|ICR_STOP
|ICR_ACKNAK
|ICR_TB
);
1045 i2c
->msg
->buf
[i2c
->msg_ptr
++] = readl(_IDBR(i2c
));
1047 if (i2c
->msg_ptr
< i2c
->msg
->len
) {
1049 * If this is the last byte of the last
1050 * message, send a STOP.
1052 if (i2c
->msg_ptr
== i2c
->msg
->len
- 1)
1053 icr
|= ICR_STOP
| ICR_ACKNAK
;
1055 icr
|= ICR_ALDIE
| ICR_TB
;
1057 i2c_pxa_master_complete(i2c
, 0);
1060 i2c
->icrlog
[i2c
->irqlogidx
-1] = icr
;
1062 writel(icr
, _ICR(i2c
));
1065 #define VALID_INT_SOURCE (ISR_SSD | ISR_ALD | ISR_ITE | ISR_IRF | \
1067 static irqreturn_t
i2c_pxa_handler(int this_irq
, void *dev_id
)
1069 struct pxa_i2c
*i2c
= dev_id
;
1070 u32 isr
= readl(_ISR(i2c
));
1072 if (!(isr
& VALID_INT_SOURCE
))
1075 if (i2c_debug
> 2 && 0) {
1076 dev_dbg(&i2c
->adap
.dev
, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
1077 __func__
, isr
, readl(_ICR(i2c
)), readl(_IBMR(i2c
)));
1081 if (i2c
->irqlogidx
< ARRAY_SIZE(i2c
->isrlog
))
1082 i2c
->isrlog
[i2c
->irqlogidx
++] = isr
;
1087 * Always clear all pending IRQs.
1089 writel(isr
& VALID_INT_SOURCE
, _ISR(i2c
));
1092 i2c_pxa_slave_start(i2c
, isr
);
1094 i2c_pxa_slave_stop(i2c
);
1096 if (i2c_pxa_is_slavemode(i2c
)) {
1098 i2c_pxa_slave_txempty(i2c
, isr
);
1100 i2c_pxa_slave_rxfull(i2c
, isr
);
1101 } else if (i2c
->msg
&& (!i2c
->highmode_enter
)) {
1103 i2c_pxa_irq_txempty(i2c
, isr
);
1105 i2c_pxa_irq_rxfull(i2c
, isr
);
1106 } else if ((isr
& ISR_ITE
) && i2c
->highmode_enter
) {
1107 i2c
->highmode_enter
= false;
1108 wake_up(&i2c
->wait
);
1110 i2c_pxa_scream_blue_murder(i2c
, "spurious irq");
1117 static int i2c_pxa_xfer(struct i2c_adapter
*adap
, struct i2c_msg msgs
[], int num
)
1119 struct pxa_i2c
*i2c
= adap
->algo_data
;
1122 for (i
= adap
->retries
; i
>= 0; i
--) {
1123 ret
= i2c_pxa_do_xfer(i2c
, msgs
, num
);
1124 if (ret
!= I2C_RETRY
)
1128 dev_dbg(&adap
->dev
, "Retrying transmission\n");
1131 i2c_pxa_scream_blue_murder(i2c
, "exhausted retries");
1134 i2c_pxa_set_slave(i2c
, ret
);
1138 static u32
i2c_pxa_functionality(struct i2c_adapter
*adap
)
1140 return I2C_FUNC_I2C
| I2C_FUNC_SMBUS_EMUL
|
1141 I2C_FUNC_PROTOCOL_MANGLING
| I2C_FUNC_NOSTART
;
1144 static const struct i2c_algorithm i2c_pxa_algorithm
= {
1145 .master_xfer
= i2c_pxa_xfer
,
1146 .functionality
= i2c_pxa_functionality
,
1149 static const struct i2c_algorithm i2c_pxa_pio_algorithm
= {
1150 .master_xfer
= i2c_pxa_pio_xfer
,
1151 .functionality
= i2c_pxa_functionality
,
1154 static const struct of_device_id i2c_pxa_dt_ids
[] = {
1155 { .compatible
= "mrvl,pxa-i2c", .data
= (void *)REGS_PXA2XX
},
1156 { .compatible
= "mrvl,pwri2c", .data
= (void *)REGS_PXA3XX
},
1157 { .compatible
= "mrvl,mmp-twsi", .data
= (void *)REGS_PXA910
},
1158 { .compatible
= "marvell,armada-3700-i2c", .data
= (void *)REGS_A3700
},
1161 MODULE_DEVICE_TABLE(of
, i2c_pxa_dt_ids
);
1163 static int i2c_pxa_probe_dt(struct platform_device
*pdev
, struct pxa_i2c
*i2c
,
1164 enum pxa_i2c_types
*i2c_types
)
1166 struct device_node
*np
= pdev
->dev
.of_node
;
1167 const struct of_device_id
*of_id
=
1168 of_match_device(i2c_pxa_dt_ids
, &pdev
->dev
);
1173 /* For device tree we always use the dynamic or alias-assigned ID */
1176 if (of_get_property(np
, "mrvl,i2c-polling", NULL
))
1178 if (of_get_property(np
, "mrvl,i2c-fast-mode", NULL
))
1181 *i2c_types
= (enum pxa_i2c_types
)(of_id
->data
);
1186 static int i2c_pxa_probe_pdata(struct platform_device
*pdev
,
1187 struct pxa_i2c
*i2c
,
1188 enum pxa_i2c_types
*i2c_types
)
1190 struct i2c_pxa_platform_data
*plat
= dev_get_platdata(&pdev
->dev
);
1191 const struct platform_device_id
*id
= platform_get_device_id(pdev
);
1193 *i2c_types
= id
->driver_data
;
1195 i2c
->use_pio
= plat
->use_pio
;
1196 i2c
->fast_mode
= plat
->fast_mode
;
1197 i2c
->high_mode
= plat
->high_mode
;
1198 i2c
->master_code
= plat
->master_code
;
1199 if (!i2c
->master_code
)
1200 i2c
->master_code
= 0xe;
1201 i2c
->rate
= plat
->rate
;
1206 static int i2c_pxa_probe(struct platform_device
*dev
)
1208 struct i2c_pxa_platform_data
*plat
= dev_get_platdata(&dev
->dev
);
1209 enum pxa_i2c_types i2c_type
;
1210 struct pxa_i2c
*i2c
;
1211 struct resource
*res
= NULL
;
1214 i2c
= devm_kzalloc(&dev
->dev
, sizeof(struct pxa_i2c
), GFP_KERNEL
);
1218 res
= platform_get_resource(dev
, IORESOURCE_MEM
, 0);
1219 i2c
->reg_base
= devm_ioremap_resource(&dev
->dev
, res
);
1220 if (IS_ERR(i2c
->reg_base
))
1221 return PTR_ERR(i2c
->reg_base
);
1223 irq
= platform_get_irq(dev
, 0);
1225 dev_err(&dev
->dev
, "no irq resource: %d\n", irq
);
1229 /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
1230 i2c
->adap
.nr
= dev
->id
;
1232 ret
= i2c_pxa_probe_dt(dev
, i2c
, &i2c_type
);
1234 ret
= i2c_pxa_probe_pdata(dev
, i2c
, &i2c_type
);
1238 i2c
->adap
.owner
= THIS_MODULE
;
1239 i2c
->adap
.retries
= 5;
1241 spin_lock_init(&i2c
->lock
);
1242 init_waitqueue_head(&i2c
->wait
);
1244 strlcpy(i2c
->adap
.name
, "pxa_i2c-i2c", sizeof(i2c
->adap
.name
));
1246 i2c
->clk
= devm_clk_get(&dev
->dev
, NULL
);
1247 if (IS_ERR(i2c
->clk
)) {
1248 dev_err(&dev
->dev
, "failed to get the clk: %ld\n", PTR_ERR(i2c
->clk
));
1249 return PTR_ERR(i2c
->clk
);
1252 i2c
->reg_ibmr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].ibmr
;
1253 i2c
->reg_idbr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].idbr
;
1254 i2c
->reg_icr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].icr
;
1255 i2c
->reg_isr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].isr
;
1256 i2c
->fm_mask
= pxa_reg_layout
[i2c_type
].fm
? : ICR_FM
;
1257 i2c
->hs_mask
= pxa_reg_layout
[i2c_type
].hs
? : ICR_HS
;
1259 if (i2c_type
!= REGS_CE4100
)
1260 i2c
->reg_isar
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].isar
;
1262 if (i2c_type
== REGS_PXA910
) {
1263 i2c
->reg_ilcr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].ilcr
;
1264 i2c
->reg_iwcr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].iwcr
;
1267 i2c
->iobase
= res
->start
;
1268 i2c
->iosize
= resource_size(res
);
1272 i2c
->slave_addr
= I2C_PXA_SLAVE_ADDR
;
1273 i2c
->highmode_enter
= false;
1276 #ifdef CONFIG_I2C_PXA_SLAVE
1277 i2c
->slave_addr
= plat
->slave_addr
;
1278 i2c
->slave
= plat
->slave
;
1280 i2c
->adap
.class = plat
->class;
1283 if (i2c
->high_mode
) {
1285 clk_set_rate(i2c
->clk
, i2c
->rate
);
1286 pr_info("i2c: <%s> set rate to %ld\n",
1287 i2c
->adap
.name
, clk_get_rate(i2c
->clk
));
1289 pr_warn("i2c: <%s> clock rate not set\n",
1293 clk_prepare_enable(i2c
->clk
);
1296 i2c
->adap
.algo
= &i2c_pxa_pio_algorithm
;
1298 i2c
->adap
.algo
= &i2c_pxa_algorithm
;
1299 ret
= devm_request_irq(&dev
->dev
, irq
, i2c_pxa_handler
,
1300 IRQF_SHARED
| IRQF_NO_SUSPEND
,
1301 dev_name(&dev
->dev
), i2c
);
1303 dev_err(&dev
->dev
, "failed to request irq: %d\n", ret
);
1310 i2c
->adap
.algo_data
= i2c
;
1311 i2c
->adap
.dev
.parent
= &dev
->dev
;
1313 i2c
->adap
.dev
.of_node
= dev
->dev
.of_node
;
1316 ret
= i2c_add_numbered_adapter(&i2c
->adap
);
1320 platform_set_drvdata(dev
, i2c
);
1322 #ifdef CONFIG_I2C_PXA_SLAVE
1323 dev_info(&i2c
->adap
.dev
, " PXA I2C adapter, slave address %d\n",
1326 dev_info(&i2c
->adap
.dev
, " PXA I2C adapter\n");
1331 clk_disable_unprepare(i2c
->clk
);
1335 static int i2c_pxa_remove(struct platform_device
*dev
)
1337 struct pxa_i2c
*i2c
= platform_get_drvdata(dev
);
1339 i2c_del_adapter(&i2c
->adap
);
1341 clk_disable_unprepare(i2c
->clk
);
1347 static int i2c_pxa_suspend_noirq(struct device
*dev
)
1349 struct pxa_i2c
*i2c
= dev_get_drvdata(dev
);
1351 clk_disable(i2c
->clk
);
1356 static int i2c_pxa_resume_noirq(struct device
*dev
)
1358 struct pxa_i2c
*i2c
= dev_get_drvdata(dev
);
1360 clk_enable(i2c
->clk
);
1366 static const struct dev_pm_ops i2c_pxa_dev_pm_ops
= {
1367 .suspend_noirq
= i2c_pxa_suspend_noirq
,
1368 .resume_noirq
= i2c_pxa_resume_noirq
,
1371 #define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
1373 #define I2C_PXA_DEV_PM_OPS NULL
1376 static struct platform_driver i2c_pxa_driver
= {
1377 .probe
= i2c_pxa_probe
,
1378 .remove
= i2c_pxa_remove
,
1380 .name
= "pxa2xx-i2c",
1381 .pm
= I2C_PXA_DEV_PM_OPS
,
1382 .of_match_table
= i2c_pxa_dt_ids
,
1384 .id_table
= i2c_pxa_id_table
,
1387 static int __init
i2c_adap_pxa_init(void)
1389 return platform_driver_register(&i2c_pxa_driver
);
1392 static void __exit
i2c_adap_pxa_exit(void)
1394 platform_driver_unregister(&i2c_pxa_driver
);
1397 MODULE_LICENSE("GPL");
1398 MODULE_ALIAS("platform:pxa2xx-i2c");
1400 subsys_initcall(i2c_adap_pxa_init
);
1401 module_exit(i2c_adap_pxa_exit
);