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
{
61 * I2C registers definitions
63 static struct pxa_reg_layout pxa_reg_layout
[] = {
83 /* no isar register */
96 static const struct platform_device_id i2c_pxa_id_table
[] = {
97 { "pxa2xx-i2c", REGS_PXA2XX
},
98 { "pxa3xx-pwri2c", REGS_PXA3XX
},
99 { "ce4100-i2c", REGS_CE4100
},
100 { "pxa910-i2c", REGS_PXA910
},
103 MODULE_DEVICE_TABLE(platform
, i2c_pxa_id_table
);
106 * I2C bit definitions
109 #define ICR_START (1 << 0) /* start bit */
110 #define ICR_STOP (1 << 1) /* stop bit */
111 #define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
112 #define ICR_TB (1 << 3) /* transfer byte bit */
113 #define ICR_MA (1 << 4) /* master abort */
114 #define ICR_SCLE (1 << 5) /* master clock enable */
115 #define ICR_IUE (1 << 6) /* unit enable */
116 #define ICR_GCD (1 << 7) /* general call disable */
117 #define ICR_ITEIE (1 << 8) /* enable tx interrupts */
118 #define ICR_IRFIE (1 << 9) /* enable rx interrupts */
119 #define ICR_BEIE (1 << 10) /* enable bus error ints */
120 #define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
121 #define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
122 #define ICR_SADIE (1 << 13) /* slave address detected int enable */
123 #define ICR_UR (1 << 14) /* unit reset */
124 #define ICR_FM (1 << 15) /* fast mode */
125 #define ICR_HS (1 << 16) /* High Speed mode */
126 #define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */
128 #define ISR_RWM (1 << 0) /* read/write mode */
129 #define ISR_ACKNAK (1 << 1) /* ack/nak status */
130 #define ISR_UB (1 << 2) /* unit busy */
131 #define ISR_IBB (1 << 3) /* bus busy */
132 #define ISR_SSD (1 << 4) /* slave stop detected */
133 #define ISR_ALD (1 << 5) /* arbitration loss detected */
134 #define ISR_ITE (1 << 6) /* tx buffer empty */
135 #define ISR_IRF (1 << 7) /* rx buffer full */
136 #define ISR_GCAD (1 << 8) /* general call address detected */
137 #define ISR_SAD (1 << 9) /* slave address detected */
138 #define ISR_BED (1 << 10) /* bus error no ACK/NAK */
140 /* bit field shift & mask */
141 #define ILCR_SLV_SHIFT 0
142 #define ILCR_SLV_MASK (0x1FF << ILCR_SLV_SHIFT)
143 #define ILCR_FLV_SHIFT 9
144 #define ILCR_FLV_MASK (0x1FF << ILCR_FLV_SHIFT)
145 #define ILCR_HLVL_SHIFT 18
146 #define ILCR_HLVL_MASK (0x1FF << ILCR_HLVL_SHIFT)
147 #define ILCR_HLVH_SHIFT 27
148 #define ILCR_HLVH_MASK (0x1F << ILCR_HLVH_SHIFT)
150 #define IWCR_CNT_SHIFT 0
151 #define IWCR_CNT_MASK (0x1F << IWCR_CNT_SHIFT)
152 #define IWCR_HS_CNT1_SHIFT 5
153 #define IWCR_HS_CNT1_MASK (0x1F << IWCR_HS_CNT1_SHIFT)
154 #define IWCR_HS_CNT2_SHIFT 10
155 #define IWCR_HS_CNT2_MASK (0x1F << IWCR_HS_CNT2_SHIFT)
159 wait_queue_head_t wait
;
161 unsigned int msg_num
;
162 unsigned int msg_idx
;
163 unsigned int msg_ptr
;
164 unsigned int slave_addr
;
165 unsigned int req_slave_addr
;
167 struct i2c_adapter adap
;
169 #ifdef CONFIG_I2C_PXA_SLAVE
170 struct i2c_slave_client
*slave
;
173 unsigned int irqlogidx
;
177 void __iomem
*reg_base
;
178 void __iomem
*reg_ibmr
;
179 void __iomem
*reg_idbr
;
180 void __iomem
*reg_icr
;
181 void __iomem
*reg_isr
;
182 void __iomem
*reg_isar
;
183 void __iomem
*reg_ilcr
;
184 void __iomem
*reg_iwcr
;
186 unsigned long iobase
;
187 unsigned long iosize
;
190 unsigned int use_pio
:1;
191 unsigned int fast_mode
:1;
192 unsigned int high_mode
:1;
193 unsigned char master_code
;
198 #define _IBMR(i2c) ((i2c)->reg_ibmr)
199 #define _IDBR(i2c) ((i2c)->reg_idbr)
200 #define _ICR(i2c) ((i2c)->reg_icr)
201 #define _ISR(i2c) ((i2c)->reg_isr)
202 #define _ISAR(i2c) ((i2c)->reg_isar)
203 #define _ILCR(i2c) ((i2c)->reg_ilcr)
204 #define _IWCR(i2c) ((i2c)->reg_iwcr)
207 * I2C Slave mode address
209 #define I2C_PXA_SLAVE_ADDR 0x1
218 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
221 decode_bits(const char *prefix
, const struct bits
*bits
, int num
, u32 val
)
223 printk("%s %08x: ", prefix
, val
);
225 const char *str
= val
& bits
->mask
? bits
->set
: bits
->unset
;
232 static const struct bits isr_bits
[] = {
233 PXA_BIT(ISR_RWM
, "RX", "TX"),
234 PXA_BIT(ISR_ACKNAK
, "NAK", "ACK"),
235 PXA_BIT(ISR_UB
, "Bsy", "Rdy"),
236 PXA_BIT(ISR_IBB
, "BusBsy", "BusRdy"),
237 PXA_BIT(ISR_SSD
, "SlaveStop", NULL
),
238 PXA_BIT(ISR_ALD
, "ALD", NULL
),
239 PXA_BIT(ISR_ITE
, "TxEmpty", NULL
),
240 PXA_BIT(ISR_IRF
, "RxFull", NULL
),
241 PXA_BIT(ISR_GCAD
, "GenCall", NULL
),
242 PXA_BIT(ISR_SAD
, "SlaveAddr", NULL
),
243 PXA_BIT(ISR_BED
, "BusErr", NULL
),
246 static void decode_ISR(unsigned int val
)
248 decode_bits(KERN_DEBUG
"ISR", isr_bits
, ARRAY_SIZE(isr_bits
), val
);
252 static const struct bits icr_bits
[] = {
253 PXA_BIT(ICR_START
, "START", NULL
),
254 PXA_BIT(ICR_STOP
, "STOP", NULL
),
255 PXA_BIT(ICR_ACKNAK
, "ACKNAK", NULL
),
256 PXA_BIT(ICR_TB
, "TB", NULL
),
257 PXA_BIT(ICR_MA
, "MA", NULL
),
258 PXA_BIT(ICR_SCLE
, "SCLE", "scle"),
259 PXA_BIT(ICR_IUE
, "IUE", "iue"),
260 PXA_BIT(ICR_GCD
, "GCD", NULL
),
261 PXA_BIT(ICR_ITEIE
, "ITEIE", NULL
),
262 PXA_BIT(ICR_IRFIE
, "IRFIE", NULL
),
263 PXA_BIT(ICR_BEIE
, "BEIE", NULL
),
264 PXA_BIT(ICR_SSDIE
, "SSDIE", NULL
),
265 PXA_BIT(ICR_ALDIE
, "ALDIE", NULL
),
266 PXA_BIT(ICR_SADIE
, "SADIE", NULL
),
267 PXA_BIT(ICR_UR
, "UR", "ur"),
270 #ifdef CONFIG_I2C_PXA_SLAVE
271 static void decode_ICR(unsigned int val
)
273 decode_bits(KERN_DEBUG
"ICR", icr_bits
, ARRAY_SIZE(icr_bits
), val
);
278 static unsigned int i2c_debug
= DEBUG
;
280 static void i2c_pxa_show_state(struct pxa_i2c
*i2c
, int lno
, const char *fname
)
282 dev_dbg(&i2c
->adap
.dev
, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname
, lno
,
283 readl(_ISR(i2c
)), readl(_ICR(i2c
)), readl(_IBMR(i2c
)));
286 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
288 static void i2c_pxa_scream_blue_murder(struct pxa_i2c
*i2c
, const char *why
)
291 struct device
*dev
= &i2c
->adap
.dev
;
293 dev_err(dev
, "slave_0x%x error: %s\n",
294 i2c
->req_slave_addr
>> 1, why
);
295 dev_err(dev
, "msg_num: %d msg_idx: %d msg_ptr: %d\n",
296 i2c
->msg_num
, i2c
->msg_idx
, i2c
->msg_ptr
);
297 dev_err(dev
, "IBMR: %08x IDBR: %08x ICR: %08x ISR: %08x\n",
298 readl(_IBMR(i2c
)), readl(_IDBR(i2c
)), readl(_ICR(i2c
)),
300 dev_dbg(dev
, "log: ");
301 for (i
= 0; i
< i2c
->irqlogidx
; i
++)
302 pr_debug("[%08x:%08x] ", i2c
->isrlog
[i
], i2c
->icrlog
[i
]);
307 #else /* ifdef DEBUG */
311 #define show_state(i2c) do { } while (0)
312 #define decode_ISR(val) do { } while (0)
313 #define decode_ICR(val) do { } while (0)
314 #define i2c_pxa_scream_blue_murder(i2c, why) do { } while (0)
316 #endif /* ifdef DEBUG / else */
318 static void i2c_pxa_master_complete(struct pxa_i2c
*i2c
, int ret
);
319 static irqreturn_t
i2c_pxa_handler(int this_irq
, void *dev_id
);
321 static inline int i2c_pxa_is_slavemode(struct pxa_i2c
*i2c
)
323 return !(readl(_ICR(i2c
)) & ICR_SCLE
);
326 static void i2c_pxa_abort(struct pxa_i2c
*i2c
)
330 if (i2c_pxa_is_slavemode(i2c
)) {
331 dev_dbg(&i2c
->adap
.dev
, "%s: called in slave mode\n", __func__
);
335 while ((i
> 0) && (readl(_IBMR(i2c
)) & 0x1) == 0) {
336 unsigned long icr
= readl(_ICR(i2c
));
339 icr
|= ICR_ACKNAK
| ICR_STOP
| ICR_TB
;
341 writel(icr
, _ICR(i2c
));
349 writel(readl(_ICR(i2c
)) & ~(ICR_MA
| ICR_START
| ICR_STOP
),
353 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c
*i2c
)
355 int timeout
= DEF_TIMEOUT
;
357 while (timeout
-- && readl(_ISR(i2c
)) & (ISR_IBB
| ISR_UB
)) {
358 if ((readl(_ISR(i2c
)) & ISR_SAD
) != 0)
368 return timeout
< 0 ? I2C_RETRY
: 0;
371 static int i2c_pxa_wait_master(struct pxa_i2c
*i2c
)
373 unsigned long timeout
= jiffies
+ HZ
*4;
375 while (time_before(jiffies
, timeout
)) {
377 dev_dbg(&i2c
->adap
.dev
, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
378 __func__
, (long)jiffies
, readl(_ISR(i2c
)), readl(_ICR(i2c
)), readl(_IBMR(i2c
)));
380 if (readl(_ISR(i2c
)) & ISR_SAD
) {
382 dev_dbg(&i2c
->adap
.dev
, "%s: Slave detected\n", __func__
);
386 /* wait for unit and bus being not busy, and we also do a
387 * quick check of the i2c lines themselves to ensure they've
390 if ((readl(_ISR(i2c
)) & (ISR_UB
| ISR_IBB
)) == 0 && readl(_IBMR(i2c
)) == 3) {
392 dev_dbg(&i2c
->adap
.dev
, "%s: done\n", __func__
);
400 dev_dbg(&i2c
->adap
.dev
, "%s: did not free\n", __func__
);
405 static int i2c_pxa_set_master(struct pxa_i2c
*i2c
)
408 dev_dbg(&i2c
->adap
.dev
, "setting to bus master\n");
410 if ((readl(_ISR(i2c
)) & (ISR_UB
| ISR_IBB
)) != 0) {
411 dev_dbg(&i2c
->adap
.dev
, "%s: unit is busy\n", __func__
);
412 if (!i2c_pxa_wait_master(i2c
)) {
413 dev_dbg(&i2c
->adap
.dev
, "%s: error: unit busy\n", __func__
);
418 writel(readl(_ICR(i2c
)) | ICR_SCLE
, _ICR(i2c
));
422 #ifdef CONFIG_I2C_PXA_SLAVE
423 static int i2c_pxa_wait_slave(struct pxa_i2c
*i2c
)
425 unsigned long timeout
= jiffies
+ HZ
*1;
431 while (time_before(jiffies
, timeout
)) {
433 dev_dbg(&i2c
->adap
.dev
, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
434 __func__
, (long)jiffies
, readl(_ISR(i2c
)), readl(_ICR(i2c
)), readl(_IBMR(i2c
)));
436 if ((readl(_ISR(i2c
)) & (ISR_UB
|ISR_IBB
)) == 0 ||
437 (readl(_ISR(i2c
)) & ISR_SAD
) != 0 ||
438 (readl(_ICR(i2c
)) & ICR_SCLE
) == 0) {
440 dev_dbg(&i2c
->adap
.dev
, "%s: done\n", __func__
);
448 dev_dbg(&i2c
->adap
.dev
, "%s: did not free\n", __func__
);
453 * clear the hold on the bus, and take of anything else
454 * that has been configured
456 static void i2c_pxa_set_slave(struct pxa_i2c
*i2c
, int errcode
)
461 udelay(100); /* simple delay */
463 /* we need to wait for the stop condition to end */
465 /* if we where in stop, then clear... */
466 if (readl(_ICR(i2c
)) & ICR_STOP
) {
468 writel(readl(_ICR(i2c
)) & ~ICR_STOP
, _ICR(i2c
));
471 if (!i2c_pxa_wait_slave(i2c
)) {
472 dev_err(&i2c
->adap
.dev
, "%s: wait timedout\n",
478 writel(readl(_ICR(i2c
)) & ~(ICR_STOP
|ICR_ACKNAK
|ICR_MA
), _ICR(i2c
));
479 writel(readl(_ICR(i2c
)) & ~ICR_SCLE
, _ICR(i2c
));
482 dev_dbg(&i2c
->adap
.dev
, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c
)), readl(_ISR(i2c
)));
483 decode_ICR(readl(_ICR(i2c
)));
487 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
490 static void i2c_pxa_reset(struct pxa_i2c
*i2c
)
492 pr_debug("Resetting I2C Controller Unit\n");
494 /* abort any transfer currently under way */
497 /* reset according to 9.8 */
498 writel(ICR_UR
, _ICR(i2c
));
499 writel(I2C_ISR_INIT
, _ISR(i2c
));
500 writel(readl(_ICR(i2c
)) & ~ICR_UR
, _ICR(i2c
));
502 if (i2c
->reg_isar
&& IS_ENABLED(CONFIG_I2C_PXA_SLAVE
))
503 writel(i2c
->slave_addr
, _ISAR(i2c
));
505 /* set control register values */
506 writel(I2C_ICR_INIT
| (i2c
->fast_mode
? ICR_FM
: 0), _ICR(i2c
));
507 writel(readl(_ICR(i2c
)) | (i2c
->high_mode
? ICR_HS
: 0), _ICR(i2c
));
509 #ifdef CONFIG_I2C_PXA_SLAVE
510 dev_info(&i2c
->adap
.dev
, "Enabling slave mode\n");
511 writel(readl(_ICR(i2c
)) | ICR_SADIE
| ICR_ALDIE
| ICR_SSDIE
, _ICR(i2c
));
514 i2c_pxa_set_slave(i2c
, 0);
517 writel(readl(_ICR(i2c
)) | ICR_IUE
, _ICR(i2c
));
522 #ifdef CONFIG_I2C_PXA_SLAVE
527 static void i2c_pxa_slave_txempty(struct pxa_i2c
*i2c
, u32 isr
)
530 /* what should we do here? */
534 if (i2c
->slave
!= NULL
)
535 ret
= i2c
->slave
->read(i2c
->slave
->data
);
537 writel(ret
, _IDBR(i2c
));
538 writel(readl(_ICR(i2c
)) | ICR_TB
, _ICR(i2c
)); /* allow next byte */
542 static void i2c_pxa_slave_rxfull(struct pxa_i2c
*i2c
, u32 isr
)
544 unsigned int byte
= readl(_IDBR(i2c
));
546 if (i2c
->slave
!= NULL
)
547 i2c
->slave
->write(i2c
->slave
->data
, byte
);
549 writel(readl(_ICR(i2c
)) | ICR_TB
, _ICR(i2c
));
552 static void i2c_pxa_slave_start(struct pxa_i2c
*i2c
, u32 isr
)
557 dev_dbg(&i2c
->adap
.dev
, "SAD, mode is slave-%cx\n",
558 (isr
& ISR_RWM
) ? 'r' : 't');
560 if (i2c
->slave
!= NULL
)
561 i2c
->slave
->event(i2c
->slave
->data
,
562 (isr
& ISR_RWM
) ? I2C_SLAVE_EVENT_START_READ
: I2C_SLAVE_EVENT_START_WRITE
);
565 * slave could interrupt in the middle of us generating a
566 * start condition... if this happens, we'd better back off
567 * and stop holding the poor thing up
569 writel(readl(_ICR(i2c
)) & ~(ICR_START
|ICR_STOP
), _ICR(i2c
));
570 writel(readl(_ICR(i2c
)) | ICR_TB
, _ICR(i2c
));
575 if ((readl(_IBMR(i2c
)) & 2) == 2)
581 dev_err(&i2c
->adap
.dev
, "timeout waiting for SCL high\n");
586 writel(readl(_ICR(i2c
)) & ~ICR_SCLE
, _ICR(i2c
));
589 static void i2c_pxa_slave_stop(struct pxa_i2c
*i2c
)
592 dev_dbg(&i2c
->adap
.dev
, "ISR: SSD (Slave Stop)\n");
594 if (i2c
->slave
!= NULL
)
595 i2c
->slave
->event(i2c
->slave
->data
, I2C_SLAVE_EVENT_STOP
);
598 dev_dbg(&i2c
->adap
.dev
, "ISR: SSD (Slave Stop) acked\n");
601 * If we have a master-mode message waiting,
602 * kick it off now that the slave has completed.
605 i2c_pxa_master_complete(i2c
, I2C_RETRY
);
608 static void i2c_pxa_slave_txempty(struct pxa_i2c
*i2c
, u32 isr
)
611 /* what should we do here? */
613 writel(0, _IDBR(i2c
));
614 writel(readl(_ICR(i2c
)) | ICR_TB
, _ICR(i2c
));
618 static void i2c_pxa_slave_rxfull(struct pxa_i2c
*i2c
, u32 isr
)
620 writel(readl(_ICR(i2c
)) | ICR_TB
| ICR_ACKNAK
, _ICR(i2c
));
623 static void i2c_pxa_slave_start(struct pxa_i2c
*i2c
, u32 isr
)
628 * slave could interrupt in the middle of us generating a
629 * start condition... if this happens, we'd better back off
630 * and stop holding the poor thing up
632 writel(readl(_ICR(i2c
)) & ~(ICR_START
|ICR_STOP
), _ICR(i2c
));
633 writel(readl(_ICR(i2c
)) | ICR_TB
| ICR_ACKNAK
, _ICR(i2c
));
638 if ((readl(_IBMR(i2c
)) & 2) == 2)
644 dev_err(&i2c
->adap
.dev
, "timeout waiting for SCL high\n");
649 writel(readl(_ICR(i2c
)) & ~ICR_SCLE
, _ICR(i2c
));
652 static void i2c_pxa_slave_stop(struct pxa_i2c
*i2c
)
655 i2c_pxa_master_complete(i2c
, I2C_RETRY
);
660 * PXA I2C Master mode
663 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg
*msg
)
665 unsigned int addr
= (msg
->addr
& 0x7f) << 1;
667 if (msg
->flags
& I2C_M_RD
)
673 static inline void i2c_pxa_start_message(struct pxa_i2c
*i2c
)
678 * Step 1: target slave address into IDBR
680 writel(i2c_pxa_addr_byte(i2c
->msg
), _IDBR(i2c
));
681 i2c
->req_slave_addr
= i2c_pxa_addr_byte(i2c
->msg
);
684 * Step 2: initiate the write.
686 icr
= readl(_ICR(i2c
)) & ~(ICR_STOP
| ICR_ALDIE
);
687 writel(icr
| ICR_START
| ICR_TB
, _ICR(i2c
));
690 static inline void i2c_pxa_stop_message(struct pxa_i2c
*i2c
)
695 * Clear the STOP and ACK flags
697 icr
= readl(_ICR(i2c
));
698 icr
&= ~(ICR_STOP
| ICR_ACKNAK
);
699 writel(icr
, _ICR(i2c
));
702 static int i2c_pxa_pio_set_master(struct pxa_i2c
*i2c
)
704 /* make timeout the same as for interrupt based functions */
705 long timeout
= 2 * DEF_TIMEOUT
;
708 * Wait for the bus to become free.
710 while (timeout
-- && readl(_ISR(i2c
)) & (ISR_IBB
| ISR_UB
)) {
717 dev_err(&i2c
->adap
.dev
,
718 "i2c_pxa: timeout waiting for bus free\n");
725 writel(readl(_ICR(i2c
)) | ICR_SCLE
, _ICR(i2c
));
731 * PXA I2C send master code
732 * 1. Load master code to IDBR and send it.
733 * Note for HS mode, set ICR [GPIOEN].
734 * 2. Wait until win arbitration.
736 static int i2c_pxa_send_mastercode(struct pxa_i2c
*i2c
)
741 spin_lock_irq(&i2c
->lock
);
742 i2c
->highmode_enter
= true;
743 writel(i2c
->master_code
, _IDBR(i2c
));
745 icr
= readl(_ICR(i2c
)) & ~(ICR_STOP
| ICR_ALDIE
);
746 icr
|= ICR_GPIOEN
| ICR_START
| ICR_TB
| ICR_ITEIE
;
747 writel(icr
, _ICR(i2c
));
749 spin_unlock_irq(&i2c
->lock
);
750 timeout
= wait_event_timeout(i2c
->wait
,
751 i2c
->highmode_enter
== false, HZ
* 1);
753 i2c
->highmode_enter
= false;
755 return (timeout
== 0) ? I2C_RETRY
: 0;
758 static int i2c_pxa_do_pio_xfer(struct pxa_i2c
*i2c
,
759 struct i2c_msg
*msg
, int num
)
761 unsigned long timeout
= 500000; /* 5 seconds */
764 ret
= i2c_pxa_pio_set_master(i2c
);
774 i2c_pxa_start_message(i2c
);
776 while (i2c
->msg_num
> 0 && --timeout
) {
777 i2c_pxa_handler(0, i2c
);
781 i2c_pxa_stop_message(i2c
);
784 * We place the return code in i2c->msg_idx.
790 i2c_pxa_scream_blue_murder(i2c
, "timeout");
798 * We are protected by the adapter bus mutex.
800 static int i2c_pxa_do_xfer(struct pxa_i2c
*i2c
, struct i2c_msg
*msg
, int num
)
806 * Wait for the bus to become free.
808 ret
= i2c_pxa_wait_bus_not_busy(i2c
);
810 dev_err(&i2c
->adap
.dev
, "i2c_pxa: timeout waiting for bus free\n");
817 ret
= i2c_pxa_set_master(i2c
);
819 dev_err(&i2c
->adap
.dev
, "i2c_pxa_set_master: error %d\n", ret
);
823 if (i2c
->high_mode
) {
824 ret
= i2c_pxa_send_mastercode(i2c
);
826 dev_err(&i2c
->adap
.dev
, "i2c_pxa_send_mastercode timeout\n");
831 spin_lock_irq(&i2c
->lock
);
839 i2c_pxa_start_message(i2c
);
841 spin_unlock_irq(&i2c
->lock
);
844 * The rest of the processing occurs in the interrupt handler.
846 timeout
= wait_event_timeout(i2c
->wait
, i2c
->msg_num
== 0, HZ
* 5);
847 i2c_pxa_stop_message(i2c
);
850 * We place the return code in i2c->msg_idx.
854 if (!timeout
&& i2c
->msg_num
) {
855 i2c_pxa_scream_blue_murder(i2c
, "timeout");
863 static int i2c_pxa_pio_xfer(struct i2c_adapter
*adap
,
864 struct i2c_msg msgs
[], int num
)
866 struct pxa_i2c
*i2c
= adap
->algo_data
;
869 /* If the I2C controller is disabled we need to reset it
870 (probably due to a suspend/resume destroying state). We do
871 this here as we can then avoid worrying about resuming the
872 controller before its users. */
873 if (!(readl(_ICR(i2c
)) & ICR_IUE
))
876 for (i
= adap
->retries
; i
>= 0; i
--) {
877 ret
= i2c_pxa_do_pio_xfer(i2c
, msgs
, num
);
878 if (ret
!= I2C_RETRY
)
882 dev_dbg(&adap
->dev
, "Retrying transmission\n");
885 i2c_pxa_scream_blue_murder(i2c
, "exhausted retries");
888 i2c_pxa_set_slave(i2c
, ret
);
893 * i2c_pxa_master_complete - complete the message and wake up.
895 static void i2c_pxa_master_complete(struct pxa_i2c
*i2c
, int ret
)
907 static void i2c_pxa_irq_txempty(struct pxa_i2c
*i2c
, u32 isr
)
909 u32 icr
= readl(_ICR(i2c
)) & ~(ICR_START
|ICR_STOP
|ICR_ACKNAK
|ICR_TB
);
913 * If ISR_ALD is set, we lost arbitration.
917 * Do we need to do anything here? The PXA docs
918 * are vague about what happens.
920 i2c_pxa_scream_blue_murder(i2c
, "ALD set");
923 * We ignore this error. We seem to see spurious ALDs
924 * for seemingly no reason. If we handle them as I think
925 * they should, we end up causing an I2C error, which
926 * is painful for some systems.
931 if ((isr
& ISR_BED
) &&
932 (!((i2c
->msg
->flags
& I2C_M_IGNORE_NAK
) &&
933 (isr
& ISR_ACKNAK
)))) {
937 * I2C bus error - either the device NAK'd us, or
938 * something more serious happened. If we were NAK'd
939 * on the initial address phase, we can retry.
941 if (isr
& ISR_ACKNAK
) {
942 if (i2c
->msg_ptr
== 0 && i2c
->msg_idx
== 0)
947 i2c_pxa_master_complete(i2c
, ret
);
948 } else if (isr
& ISR_RWM
) {
950 * Read mode. We have just sent the address byte, and
951 * now we must initiate the transfer.
953 if (i2c
->msg_ptr
== i2c
->msg
->len
- 1 &&
954 i2c
->msg_idx
== i2c
->msg_num
- 1)
955 icr
|= ICR_STOP
| ICR_ACKNAK
;
957 icr
|= ICR_ALDIE
| ICR_TB
;
958 } else if (i2c
->msg_ptr
< i2c
->msg
->len
) {
960 * Write mode. Write the next data byte.
962 writel(i2c
->msg
->buf
[i2c
->msg_ptr
++], _IDBR(i2c
));
964 icr
|= ICR_ALDIE
| ICR_TB
;
967 * If this is the last byte of the last message or last byte
968 * of any message with I2C_M_STOP (e.g. SCCB), send a STOP.
970 if ((i2c
->msg_ptr
== i2c
->msg
->len
) &&
971 ((i2c
->msg
->flags
& I2C_M_STOP
) ||
972 (i2c
->msg_idx
== i2c
->msg_num
- 1)))
975 } else if (i2c
->msg_idx
< i2c
->msg_num
- 1) {
977 * Next segment of the message.
984 * If we aren't doing a repeated start and address,
985 * go back and try to send the next byte. Note that
986 * we do not support switching the R/W direction here.
988 if (i2c
->msg
->flags
& I2C_M_NOSTART
)
992 * Write the next address.
994 writel(i2c_pxa_addr_byte(i2c
->msg
), _IDBR(i2c
));
995 i2c
->req_slave_addr
= i2c_pxa_addr_byte(i2c
->msg
);
998 * And trigger a repeated start, and send the byte.
1001 icr
|= ICR_START
| ICR_TB
;
1003 if (i2c
->msg
->len
== 0) {
1005 * Device probes have a message length of zero
1006 * and need the bus to be reset before it can
1011 i2c_pxa_master_complete(i2c
, 0);
1014 i2c
->icrlog
[i2c
->irqlogidx
-1] = icr
;
1016 writel(icr
, _ICR(i2c
));
1020 static void i2c_pxa_irq_rxfull(struct pxa_i2c
*i2c
, u32 isr
)
1022 u32 icr
= readl(_ICR(i2c
)) & ~(ICR_START
|ICR_STOP
|ICR_ACKNAK
|ICR_TB
);
1027 i2c
->msg
->buf
[i2c
->msg_ptr
++] = readl(_IDBR(i2c
));
1029 if (i2c
->msg_ptr
< i2c
->msg
->len
) {
1031 * If this is the last byte of the last
1032 * message, send a STOP.
1034 if (i2c
->msg_ptr
== i2c
->msg
->len
- 1)
1035 icr
|= ICR_STOP
| ICR_ACKNAK
;
1037 icr
|= ICR_ALDIE
| ICR_TB
;
1039 i2c_pxa_master_complete(i2c
, 0);
1042 i2c
->icrlog
[i2c
->irqlogidx
-1] = icr
;
1044 writel(icr
, _ICR(i2c
));
1047 #define VALID_INT_SOURCE (ISR_SSD | ISR_ALD | ISR_ITE | ISR_IRF | \
1049 static irqreturn_t
i2c_pxa_handler(int this_irq
, void *dev_id
)
1051 struct pxa_i2c
*i2c
= dev_id
;
1052 u32 isr
= readl(_ISR(i2c
));
1054 if (!(isr
& VALID_INT_SOURCE
))
1057 if (i2c_debug
> 2 && 0) {
1058 dev_dbg(&i2c
->adap
.dev
, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
1059 __func__
, isr
, readl(_ICR(i2c
)), readl(_IBMR(i2c
)));
1063 if (i2c
->irqlogidx
< ARRAY_SIZE(i2c
->isrlog
))
1064 i2c
->isrlog
[i2c
->irqlogidx
++] = isr
;
1069 * Always clear all pending IRQs.
1071 writel(isr
& VALID_INT_SOURCE
, _ISR(i2c
));
1074 i2c_pxa_slave_start(i2c
, isr
);
1076 i2c_pxa_slave_stop(i2c
);
1078 if (i2c_pxa_is_slavemode(i2c
)) {
1080 i2c_pxa_slave_txempty(i2c
, isr
);
1082 i2c_pxa_slave_rxfull(i2c
, isr
);
1083 } else if (i2c
->msg
&& (!i2c
->highmode_enter
)) {
1085 i2c_pxa_irq_txempty(i2c
, isr
);
1087 i2c_pxa_irq_rxfull(i2c
, isr
);
1088 } else if ((isr
& ISR_ITE
) && i2c
->highmode_enter
) {
1089 i2c
->highmode_enter
= false;
1090 wake_up(&i2c
->wait
);
1092 i2c_pxa_scream_blue_murder(i2c
, "spurious irq");
1099 static int i2c_pxa_xfer(struct i2c_adapter
*adap
, struct i2c_msg msgs
[], int num
)
1101 struct pxa_i2c
*i2c
= adap
->algo_data
;
1104 for (i
= adap
->retries
; i
>= 0; i
--) {
1105 ret
= i2c_pxa_do_xfer(i2c
, msgs
, num
);
1106 if (ret
!= I2C_RETRY
)
1110 dev_dbg(&adap
->dev
, "Retrying transmission\n");
1113 i2c_pxa_scream_blue_murder(i2c
, "exhausted retries");
1116 i2c_pxa_set_slave(i2c
, ret
);
1120 static u32
i2c_pxa_functionality(struct i2c_adapter
*adap
)
1122 return I2C_FUNC_I2C
| I2C_FUNC_SMBUS_EMUL
|
1123 I2C_FUNC_PROTOCOL_MANGLING
| I2C_FUNC_NOSTART
;
1126 static const struct i2c_algorithm i2c_pxa_algorithm
= {
1127 .master_xfer
= i2c_pxa_xfer
,
1128 .functionality
= i2c_pxa_functionality
,
1131 static const struct i2c_algorithm i2c_pxa_pio_algorithm
= {
1132 .master_xfer
= i2c_pxa_pio_xfer
,
1133 .functionality
= i2c_pxa_functionality
,
1136 static const struct of_device_id i2c_pxa_dt_ids
[] = {
1137 { .compatible
= "mrvl,pxa-i2c", .data
= (void *)REGS_PXA2XX
},
1138 { .compatible
= "mrvl,pwri2c", .data
= (void *)REGS_PXA3XX
},
1139 { .compatible
= "mrvl,mmp-twsi", .data
= (void *)REGS_PXA910
},
1142 MODULE_DEVICE_TABLE(of
, i2c_pxa_dt_ids
);
1144 static int i2c_pxa_probe_dt(struct platform_device
*pdev
, struct pxa_i2c
*i2c
,
1145 enum pxa_i2c_types
*i2c_types
)
1147 struct device_node
*np
= pdev
->dev
.of_node
;
1148 const struct of_device_id
*of_id
=
1149 of_match_device(i2c_pxa_dt_ids
, &pdev
->dev
);
1154 /* For device tree we always use the dynamic or alias-assigned ID */
1157 if (of_get_property(np
, "mrvl,i2c-polling", NULL
))
1159 if (of_get_property(np
, "mrvl,i2c-fast-mode", NULL
))
1162 *i2c_types
= (enum pxa_i2c_types
)(of_id
->data
);
1167 static int i2c_pxa_probe_pdata(struct platform_device
*pdev
,
1168 struct pxa_i2c
*i2c
,
1169 enum pxa_i2c_types
*i2c_types
)
1171 struct i2c_pxa_platform_data
*plat
= dev_get_platdata(&pdev
->dev
);
1172 const struct platform_device_id
*id
= platform_get_device_id(pdev
);
1174 *i2c_types
= id
->driver_data
;
1176 i2c
->use_pio
= plat
->use_pio
;
1177 i2c
->fast_mode
= plat
->fast_mode
;
1178 i2c
->high_mode
= plat
->high_mode
;
1179 i2c
->master_code
= plat
->master_code
;
1180 if (!i2c
->master_code
)
1181 i2c
->master_code
= 0xe;
1182 i2c
->rate
= plat
->rate
;
1187 static int i2c_pxa_probe(struct platform_device
*dev
)
1189 struct i2c_pxa_platform_data
*plat
= dev_get_platdata(&dev
->dev
);
1190 enum pxa_i2c_types i2c_type
;
1191 struct pxa_i2c
*i2c
;
1192 struct resource
*res
= NULL
;
1195 i2c
= devm_kzalloc(&dev
->dev
, sizeof(struct pxa_i2c
), GFP_KERNEL
);
1199 res
= platform_get_resource(dev
, IORESOURCE_MEM
, 0);
1200 i2c
->reg_base
= devm_ioremap_resource(&dev
->dev
, res
);
1201 if (IS_ERR(i2c
->reg_base
))
1202 return PTR_ERR(i2c
->reg_base
);
1204 irq
= platform_get_irq(dev
, 0);
1206 dev_err(&dev
->dev
, "no irq resource: %d\n", irq
);
1210 /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
1211 i2c
->adap
.nr
= dev
->id
;
1213 ret
= i2c_pxa_probe_dt(dev
, i2c
, &i2c_type
);
1215 ret
= i2c_pxa_probe_pdata(dev
, i2c
, &i2c_type
);
1219 i2c
->adap
.owner
= THIS_MODULE
;
1220 i2c
->adap
.retries
= 5;
1222 spin_lock_init(&i2c
->lock
);
1223 init_waitqueue_head(&i2c
->wait
);
1225 strlcpy(i2c
->adap
.name
, "pxa_i2c-i2c", sizeof(i2c
->adap
.name
));
1227 i2c
->clk
= devm_clk_get(&dev
->dev
, NULL
);
1228 if (IS_ERR(i2c
->clk
)) {
1229 dev_err(&dev
->dev
, "failed to get the clk: %ld\n", PTR_ERR(i2c
->clk
));
1230 return PTR_ERR(i2c
->clk
);
1233 i2c
->reg_ibmr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].ibmr
;
1234 i2c
->reg_idbr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].idbr
;
1235 i2c
->reg_icr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].icr
;
1236 i2c
->reg_isr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].isr
;
1237 if (i2c_type
!= REGS_CE4100
)
1238 i2c
->reg_isar
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].isar
;
1240 if (i2c_type
== REGS_PXA910
) {
1241 i2c
->reg_ilcr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].ilcr
;
1242 i2c
->reg_iwcr
= i2c
->reg_base
+ pxa_reg_layout
[i2c_type
].iwcr
;
1245 i2c
->iobase
= res
->start
;
1246 i2c
->iosize
= resource_size(res
);
1250 i2c
->slave_addr
= I2C_PXA_SLAVE_ADDR
;
1251 i2c
->highmode_enter
= false;
1254 #ifdef CONFIG_I2C_PXA_SLAVE
1255 i2c
->slave_addr
= plat
->slave_addr
;
1256 i2c
->slave
= plat
->slave
;
1258 i2c
->adap
.class = plat
->class;
1261 if (i2c
->high_mode
) {
1263 clk_set_rate(i2c
->clk
, i2c
->rate
);
1264 pr_info("i2c: <%s> set rate to %ld\n",
1265 i2c
->adap
.name
, clk_get_rate(i2c
->clk
));
1267 pr_warn("i2c: <%s> clock rate not set\n",
1271 clk_prepare_enable(i2c
->clk
);
1274 i2c
->adap
.algo
= &i2c_pxa_pio_algorithm
;
1276 i2c
->adap
.algo
= &i2c_pxa_algorithm
;
1277 ret
= devm_request_irq(&dev
->dev
, irq
, i2c_pxa_handler
,
1278 IRQF_SHARED
| IRQF_NO_SUSPEND
,
1279 dev_name(&dev
->dev
), i2c
);
1281 dev_err(&dev
->dev
, "failed to request irq: %d\n", ret
);
1288 i2c
->adap
.algo_data
= i2c
;
1289 i2c
->adap
.dev
.parent
= &dev
->dev
;
1291 i2c
->adap
.dev
.of_node
= dev
->dev
.of_node
;
1294 ret
= i2c_add_numbered_adapter(&i2c
->adap
);
1296 dev_err(&dev
->dev
, "failed to add bus: %d\n", ret
);
1300 platform_set_drvdata(dev
, i2c
);
1302 #ifdef CONFIG_I2C_PXA_SLAVE
1303 dev_info(&i2c
->adap
.dev
, " PXA I2C adapter, slave address %d\n",
1306 dev_info(&i2c
->adap
.dev
, " PXA I2C adapter\n");
1311 clk_disable_unprepare(i2c
->clk
);
1315 static int i2c_pxa_remove(struct platform_device
*dev
)
1317 struct pxa_i2c
*i2c
= platform_get_drvdata(dev
);
1319 i2c_del_adapter(&i2c
->adap
);
1321 clk_disable_unprepare(i2c
->clk
);
1327 static int i2c_pxa_suspend_noirq(struct device
*dev
)
1329 struct platform_device
*pdev
= to_platform_device(dev
);
1330 struct pxa_i2c
*i2c
= platform_get_drvdata(pdev
);
1332 clk_disable(i2c
->clk
);
1337 static int i2c_pxa_resume_noirq(struct device
*dev
)
1339 struct platform_device
*pdev
= to_platform_device(dev
);
1340 struct pxa_i2c
*i2c
= platform_get_drvdata(pdev
);
1342 clk_enable(i2c
->clk
);
1348 static const struct dev_pm_ops i2c_pxa_dev_pm_ops
= {
1349 .suspend_noirq
= i2c_pxa_suspend_noirq
,
1350 .resume_noirq
= i2c_pxa_resume_noirq
,
1353 #define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
1355 #define I2C_PXA_DEV_PM_OPS NULL
1358 static struct platform_driver i2c_pxa_driver
= {
1359 .probe
= i2c_pxa_probe
,
1360 .remove
= i2c_pxa_remove
,
1362 .name
= "pxa2xx-i2c",
1363 .pm
= I2C_PXA_DEV_PM_OPS
,
1364 .of_match_table
= i2c_pxa_dt_ids
,
1366 .id_table
= i2c_pxa_id_table
,
1369 static int __init
i2c_adap_pxa_init(void)
1371 return platform_driver_register(&i2c_pxa_driver
);
1374 static void __exit
i2c_adap_pxa_exit(void)
1376 platform_driver_unregister(&i2c_pxa_driver
);
1379 MODULE_LICENSE("GPL");
1380 MODULE_ALIAS("platform:pxa2xx-i2c");
1382 subsys_initcall(i2c_adap_pxa_init
);
1383 module_exit(i2c_adap_pxa_exit
);