Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / drivers / i2c / busses / i2c-pxa.c
blobfbf91d383b40938fa248db3e34b30a864112cde0
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/platform_data/i2c-pxa.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;
49 u32 ilcr;
50 u32 iwcr;
51 u32 fm;
52 u32 hs;
55 enum pxa_i2c_types {
56 REGS_PXA2XX,
57 REGS_PXA3XX,
58 REGS_CE4100,
59 REGS_PXA910,
60 REGS_A3700,
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[] = {
70 [REGS_PXA2XX] = {
71 .ibmr = 0x00,
72 .idbr = 0x08,
73 .icr = 0x10,
74 .isr = 0x18,
75 .isar = 0x20,
77 [REGS_PXA3XX] = {
78 .ibmr = 0x00,
79 .idbr = 0x04,
80 .icr = 0x08,
81 .isr = 0x0c,
82 .isar = 0x10,
84 [REGS_CE4100] = {
85 .ibmr = 0x14,
86 .idbr = 0x0c,
87 .icr = 0x00,
88 .isr = 0x04,
89 /* no isar register */
91 [REGS_PXA910] = {
92 .ibmr = 0x00,
93 .idbr = 0x08,
94 .icr = 0x10,
95 .isr = 0x18,
96 .isar = 0x20,
97 .ilcr = 0x28,
98 .iwcr = 0x30,
100 [REGS_A3700] = {
101 .ibmr = 0x00,
102 .idbr = 0x04,
103 .icr = 0x08,
104 .isr = 0x0c,
105 .isar = 0x10,
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 },
117 { },
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)
173 struct pxa_i2c {
174 spinlock_t lock;
175 wait_queue_head_t wait;
176 struct i2c_msg *msg;
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;
184 struct clk *clk;
185 #ifdef CONFIG_I2C_PXA_SLAVE
186 struct i2c_slave_client *slave;
187 #endif
189 unsigned int irqlogidx;
190 u32 isrlog[32];
191 u32 icrlog[32];
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;
205 int irq;
206 unsigned int use_pio :1;
207 unsigned int fast_mode :1;
208 unsigned int high_mode:1;
209 unsigned char master_code;
210 unsigned long rate;
211 bool highmode_enter;
212 u32 fm_mask;
213 u32 hs_mask;
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
229 #ifdef DEBUG
231 struct bits {
232 u32 mask;
233 const char *set;
234 const char *unset;
236 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
238 static inline void
239 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
241 printk("%s %08x: ", prefix, val);
242 while (num--) {
243 const char *str = val & bits->mask ? bits->set : bits->unset;
244 if (str)
245 printk("%s ", str);
246 bits++;
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);
267 printk("\n");
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);
292 printk("\n");
294 #endif
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)
308 unsigned int i;
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)),
317 readl(_ISR(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]);
322 pr_debug("\n");
325 #else /* ifdef DEBUG */
327 #define i2c_debug 0
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)
346 int i = 250;
348 if (i2c_pxa_is_slavemode(i2c)) {
349 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
350 return;
353 while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
354 unsigned long icr = readl(_ICR(i2c));
356 icr &= ~ICR_START;
357 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
359 writel(icr, _ICR(i2c));
361 show_state(i2c);
363 mdelay(1);
364 i --;
367 writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
368 _ICR(i2c));
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)
377 timeout += 4;
379 msleep(2);
380 show_state(i2c);
383 if (timeout < 0)
384 show_state(i2c);
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)) {
394 if (i2c_debug > 1)
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) {
399 if (i2c_debug > 0)
400 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
401 goto out;
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
406 * gone high...
408 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
409 if (i2c_debug > 0)
410 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
411 return 1;
414 msleep(1);
417 if (i2c_debug > 0)
418 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
419 out:
420 return 0;
423 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
425 if (i2c_debug)
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__);
432 return I2C_RETRY;
436 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
437 return 0;
440 #ifdef CONFIG_I2C_PXA_SLAVE
441 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
443 unsigned long timeout = jiffies + HZ*1;
445 /* wait for stop */
447 show_state(i2c);
449 while (time_before(jiffies, timeout)) {
450 if (i2c_debug > 1)
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) {
457 if (i2c_debug > 1)
458 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
459 return 1;
462 msleep(1);
465 if (i2c_debug > 0)
466 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
467 return 0;
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)
476 show_state(i2c);
478 if (errcode < 0) {
479 udelay(100); /* simple delay */
480 } else {
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) {
485 udelay(100);
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",
491 __func__);
492 return;
496 writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
497 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
499 if (i2c_debug) {
500 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
501 decode_ICR(readl(_ICR(i2c)));
504 #else
505 #define i2c_pxa_set_slave(i2c, err) do { } while (0)
506 #endif
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 */
513 i2c_pxa_abort(i2c);
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));
530 #endif
532 i2c_pxa_set_slave(i2c, 0);
534 /* enable unit */
535 writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
536 udelay(100);
540 #ifdef CONFIG_I2C_PXA_SLAVE
542 * PXA I2C Slave mode
545 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
547 if (isr & ISR_BED) {
548 /* what should we do here? */
549 } else {
550 int ret = 0;
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)
572 int timeout;
574 if (i2c_debug > 0)
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));
590 timeout = 0x10000;
592 while (1) {
593 if ((readl(_IBMR(i2c)) & 2) == 2)
594 break;
596 timeout--;
598 if (timeout <= 0) {
599 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
600 break;
604 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
607 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
609 if (i2c_debug > 2)
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);
615 if (i2c_debug > 2)
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.
622 if (i2c->msg)
623 i2c_pxa_master_complete(i2c, I2C_RETRY);
625 #else
626 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
628 if (isr & ISR_BED) {
629 /* what should we do here? */
630 } else {
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)
643 int timeout;
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));
653 timeout = 0x10000;
655 while (1) {
656 if ((readl(_IBMR(i2c)) & 2) == 2)
657 break;
659 timeout--;
661 if (timeout <= 0) {
662 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
663 break;
667 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
670 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
672 if (i2c->msg)
673 i2c_pxa_master_complete(i2c, I2C_RETRY);
675 #endif
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)
686 addr |= 1;
688 return addr;
691 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
693 u32 icr;
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)
710 u32 icr;
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)) {
729 udelay(1000);
730 show_state(i2c);
733 if (timeout < 0) {
734 show_state(i2c);
735 dev_err(&i2c->adap.dev,
736 "i2c_pxa: timeout waiting for bus free\n");
737 return I2C_RETRY;
741 * Set master mode.
743 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
745 return 0;
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)
756 u32 icr;
757 long timeout;
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 */
780 int ret = 0;
782 ret = i2c_pxa_pio_set_master(i2c);
783 if (ret)
784 goto out;
786 i2c->msg = msg;
787 i2c->msg_num = num;
788 i2c->msg_idx = 0;
789 i2c->msg_ptr = 0;
790 i2c->irqlogidx = 0;
792 i2c_pxa_start_message(i2c);
794 while (i2c->msg_num > 0 && --timeout) {
795 i2c_pxa_handler(0, i2c);
796 udelay(10);
799 i2c_pxa_stop_message(i2c);
802 * We place the return code in i2c->msg_idx.
804 ret = i2c->msg_idx;
806 out:
807 if (timeout == 0) {
808 i2c_pxa_scream_blue_murder(i2c, "timeout");
809 ret = I2C_RETRY;
812 return ret;
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)
820 long timeout;
821 int ret;
824 * Wait for the bus to become free.
826 ret = i2c_pxa_wait_bus_not_busy(i2c);
827 if (ret) {
828 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
829 goto out;
833 * Set master mode.
835 ret = i2c_pxa_set_master(i2c);
836 if (ret) {
837 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
838 goto out;
841 if (i2c->high_mode) {
842 ret = i2c_pxa_send_mastercode(i2c);
843 if (ret) {
844 dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
845 goto out;
849 spin_lock_irq(&i2c->lock);
851 i2c->msg = msg;
852 i2c->msg_num = num;
853 i2c->msg_idx = 0;
854 i2c->msg_ptr = 0;
855 i2c->irqlogidx = 0;
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.
870 ret = i2c->msg_idx;
872 if (!timeout && i2c->msg_num) {
873 i2c_pxa_scream_blue_murder(i2c, "timeout");
874 ret = I2C_RETRY;
877 out:
878 return ret;
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;
885 int ret, i;
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))
892 i2c_pxa_reset(i2c);
894 for (i = adap->retries; i >= 0; i--) {
895 ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
896 if (ret != I2C_RETRY)
897 goto out;
899 if (i2c_debug)
900 dev_dbg(&adap->dev, "Retrying transmission\n");
901 udelay(100);
903 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
904 ret = -EREMOTEIO;
905 out:
906 i2c_pxa_set_slave(i2c, ret);
907 return 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)
915 i2c->msg_ptr = 0;
916 i2c->msg = NULL;
917 i2c->msg_idx ++;
918 i2c->msg_num = 0;
919 if (ret)
920 i2c->msg_idx = ret;
921 if (!i2c->use_pio)
922 wake_up(&i2c->wait);
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);
929 again:
931 * If ISR_ALD is set, we lost arbitration.
933 if (isr & ISR_ALD) {
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.
946 return; /* ignore */
949 if ((isr & ISR_BED) &&
950 (!((i2c->msg->flags & I2C_M_IGNORE_NAK) &&
951 (isr & ISR_ACKNAK)))) {
952 int ret = BUS_ERROR;
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)
961 ret = I2C_RETRY;
962 else
963 ret = XFER_NAKED;
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)))
991 icr |= ICR_STOP;
993 } else if (i2c->msg_idx < i2c->msg_num - 1) {
995 * Next segment of the message.
997 i2c->msg_ptr = 0;
998 i2c->msg_idx ++;
999 i2c->msg++;
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)
1007 goto again;
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.
1018 icr &= ~ICR_ALDIE;
1019 icr |= ICR_START | ICR_TB;
1020 } else {
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
1025 * be used again.
1027 i2c_pxa_reset(i2c);
1029 i2c_pxa_master_complete(i2c, 0);
1032 i2c->icrlog[i2c->irqlogidx-1] = icr;
1034 writel(icr, _ICR(i2c));
1035 show_state(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);
1043 * Read the byte.
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;
1056 } else {
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 | \
1066 ISR_SAD | ISR_BED)
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))
1073 return IRQ_NONE;
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)));
1078 decode_ISR(isr);
1081 if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
1082 i2c->isrlog[i2c->irqlogidx++] = isr;
1084 show_state(i2c);
1087 * Always clear all pending IRQs.
1089 writel(isr & VALID_INT_SOURCE, _ISR(i2c));
1091 if (isr & ISR_SAD)
1092 i2c_pxa_slave_start(i2c, isr);
1093 if (isr & ISR_SSD)
1094 i2c_pxa_slave_stop(i2c);
1096 if (i2c_pxa_is_slavemode(i2c)) {
1097 if (isr & ISR_ITE)
1098 i2c_pxa_slave_txempty(i2c, isr);
1099 if (isr & ISR_IRF)
1100 i2c_pxa_slave_rxfull(i2c, isr);
1101 } else if (i2c->msg && (!i2c->highmode_enter)) {
1102 if (isr & ISR_ITE)
1103 i2c_pxa_irq_txempty(i2c, isr);
1104 if (isr & ISR_IRF)
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);
1109 } else {
1110 i2c_pxa_scream_blue_murder(i2c, "spurious irq");
1113 return IRQ_HANDLED;
1117 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
1119 struct pxa_i2c *i2c = adap->algo_data;
1120 int ret, i;
1122 for (i = adap->retries; i >= 0; i--) {
1123 ret = i2c_pxa_do_xfer(i2c, msgs, num);
1124 if (ret != I2C_RETRY)
1125 goto out;
1127 if (i2c_debug)
1128 dev_dbg(&adap->dev, "Retrying transmission\n");
1129 udelay(100);
1131 i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
1132 ret = -EREMOTEIO;
1133 out:
1134 i2c_pxa_set_slave(i2c, ret);
1135 return 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);
1170 if (!of_id)
1171 return 1;
1173 /* For device tree we always use the dynamic or alias-assigned ID */
1174 i2c->adap.nr = -1;
1176 if (of_get_property(np, "mrvl,i2c-polling", NULL))
1177 i2c->use_pio = 1;
1178 if (of_get_property(np, "mrvl,i2c-fast-mode", NULL))
1179 i2c->fast_mode = 1;
1181 *i2c_types = (enum pxa_i2c_types)(of_id->data);
1183 return 0;
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;
1194 if (plat) {
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;
1203 return 0;
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;
1212 int ret, irq;
1214 i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
1215 if (!i2c)
1216 return -ENOMEM;
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);
1224 if (irq < 0) {
1225 dev_err(&dev->dev, "no irq resource: %d\n", irq);
1226 return 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);
1233 if (ret > 0)
1234 ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
1235 if (ret < 0)
1236 return ret;
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);
1270 i2c->irq = irq;
1272 i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1273 i2c->highmode_enter = false;
1275 if (plat) {
1276 #ifdef CONFIG_I2C_PXA_SLAVE
1277 i2c->slave_addr = plat->slave_addr;
1278 i2c->slave = plat->slave;
1279 #endif
1280 i2c->adap.class = plat->class;
1283 if (i2c->high_mode) {
1284 if (i2c->rate) {
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));
1288 } else
1289 pr_warn("i2c: <%s> clock rate not set\n",
1290 i2c->adap.name);
1293 clk_prepare_enable(i2c->clk);
1295 if (i2c->use_pio) {
1296 i2c->adap.algo = &i2c_pxa_pio_algorithm;
1297 } else {
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);
1302 if (ret) {
1303 dev_err(&dev->dev, "failed to request irq: %d\n", ret);
1304 goto ereqirq;
1308 i2c_pxa_reset(i2c);
1310 i2c->adap.algo_data = i2c;
1311 i2c->adap.dev.parent = &dev->dev;
1312 #ifdef CONFIG_OF
1313 i2c->adap.dev.of_node = dev->dev.of_node;
1314 #endif
1316 ret = i2c_add_numbered_adapter(&i2c->adap);
1317 if (ret < 0)
1318 goto ereqirq;
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",
1324 i2c->slave_addr);
1325 #else
1326 dev_info(&i2c->adap.dev, " PXA I2C adapter\n");
1327 #endif
1328 return 0;
1330 ereqirq:
1331 clk_disable_unprepare(i2c->clk);
1332 return ret;
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);
1343 return 0;
1346 #ifdef CONFIG_PM
1347 static int i2c_pxa_suspend_noirq(struct device *dev)
1349 struct pxa_i2c *i2c = dev_get_drvdata(dev);
1351 clk_disable(i2c->clk);
1353 return 0;
1356 static int i2c_pxa_resume_noirq(struct device *dev)
1358 struct pxa_i2c *i2c = dev_get_drvdata(dev);
1360 clk_enable(i2c->clk);
1361 i2c_pxa_reset(i2c);
1363 return 0;
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)
1372 #else
1373 #define I2C_PXA_DEV_PM_OPS NULL
1374 #endif
1376 static struct platform_driver i2c_pxa_driver = {
1377 .probe = i2c_pxa_probe,
1378 .remove = i2c_pxa_remove,
1379 .driver = {
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);