xref: /openbmc/linux/drivers/i2c/busses/i2c-pxa.c (revision 206a81c1)
1 /*
2  *  i2c_adap_pxa.c
3  *
4  *  I2C adapter for the PXA I2C bus access.
5  *
6  *  Copyright (C) 2002 Intrinsyc Software Inc.
7  *  Copyright (C) 2004-2005 Deep Blue Solutions Ltd.
8  *
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.
12  *
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]
21  */
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/i2c.h>
25 #include <linux/init.h>
26 #include <linux/time.h>
27 #include <linux/sched.h>
28 #include <linux/delay.h>
29 #include <linux/errno.h>
30 #include <linux/interrupt.h>
31 #include <linux/i2c-pxa.h>
32 #include <linux/of.h>
33 #include <linux/of_device.h>
34 #include <linux/platform_device.h>
35 #include <linux/err.h>
36 #include <linux/clk.h>
37 #include <linux/slab.h>
38 #include <linux/io.h>
39 #include <linux/i2c/pxa-i2c.h>
40 
41 #include <asm/irq.h>
42 
43 struct pxa_reg_layout {
44 	u32 ibmr;
45 	u32 idbr;
46 	u32 icr;
47 	u32 isr;
48 	u32 isar;
49 };
50 
51 enum pxa_i2c_types {
52 	REGS_PXA2XX,
53 	REGS_PXA3XX,
54 	REGS_CE4100,
55 };
56 
57 /*
58  * I2C registers definitions
59  */
60 static struct pxa_reg_layout pxa_reg_layout[] = {
61 	[REGS_PXA2XX] = {
62 		.ibmr =	0x00,
63 		.idbr =	0x08,
64 		.icr =	0x10,
65 		.isr =	0x18,
66 		.isar =	0x20,
67 	},
68 	[REGS_PXA3XX] = {
69 		.ibmr =	0x00,
70 		.idbr =	0x04,
71 		.icr =	0x08,
72 		.isr =	0x0c,
73 		.isar =	0x10,
74 	},
75 	[REGS_CE4100] = {
76 		.ibmr =	0x14,
77 		.idbr =	0x0c,
78 		.icr =	0x00,
79 		.isr =	0x04,
80 		/* no isar register */
81 	},
82 };
83 
84 static const struct platform_device_id i2c_pxa_id_table[] = {
85 	{ "pxa2xx-i2c",		REGS_PXA2XX },
86 	{ "pxa3xx-pwri2c",	REGS_PXA3XX },
87 	{ "ce4100-i2c",		REGS_CE4100 },
88 	{ },
89 };
90 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
91 
92 /*
93  * I2C bit definitions
94  */
95 
96 #define ICR_START	(1 << 0)	   /* start bit */
97 #define ICR_STOP	(1 << 1)	   /* stop bit */
98 #define ICR_ACKNAK	(1 << 2)	   /* send ACK(0) or NAK(1) */
99 #define ICR_TB		(1 << 3)	   /* transfer byte bit */
100 #define ICR_MA		(1 << 4)	   /* master abort */
101 #define ICR_SCLE	(1 << 5)	   /* master clock enable */
102 #define ICR_IUE		(1 << 6)	   /* unit enable */
103 #define ICR_GCD		(1 << 7)	   /* general call disable */
104 #define ICR_ITEIE	(1 << 8)	   /* enable tx interrupts */
105 #define ICR_IRFIE	(1 << 9)	   /* enable rx interrupts */
106 #define ICR_BEIE	(1 << 10)	   /* enable bus error ints */
107 #define ICR_SSDIE	(1 << 11)	   /* slave STOP detected int enable */
108 #define ICR_ALDIE	(1 << 12)	   /* enable arbitration interrupt */
109 #define ICR_SADIE	(1 << 13)	   /* slave address detected int enable */
110 #define ICR_UR		(1 << 14)	   /* unit reset */
111 #define ICR_FM		(1 << 15)	   /* fast mode */
112 #define ICR_HS		(1 << 16)	   /* High Speed mode */
113 #define ICR_GPIOEN	(1 << 19)	   /* enable GPIO mode for SCL in HS */
114 
115 #define ISR_RWM		(1 << 0)	   /* read/write mode */
116 #define ISR_ACKNAK	(1 << 1)	   /* ack/nak status */
117 #define ISR_UB		(1 << 2)	   /* unit busy */
118 #define ISR_IBB		(1 << 3)	   /* bus busy */
119 #define ISR_SSD		(1 << 4)	   /* slave stop detected */
120 #define ISR_ALD		(1 << 5)	   /* arbitration loss detected */
121 #define ISR_ITE		(1 << 6)	   /* tx buffer empty */
122 #define ISR_IRF		(1 << 7)	   /* rx buffer full */
123 #define ISR_GCAD	(1 << 8)	   /* general call address detected */
124 #define ISR_SAD		(1 << 9)	   /* slave address detected */
125 #define ISR_BED		(1 << 10)	   /* bus error no ACK/NAK */
126 
127 struct pxa_i2c {
128 	spinlock_t		lock;
129 	wait_queue_head_t	wait;
130 	struct i2c_msg		*msg;
131 	unsigned int		msg_num;
132 	unsigned int		msg_idx;
133 	unsigned int		msg_ptr;
134 	unsigned int		slave_addr;
135 
136 	struct i2c_adapter	adap;
137 	struct clk		*clk;
138 #ifdef CONFIG_I2C_PXA_SLAVE
139 	struct i2c_slave_client *slave;
140 #endif
141 
142 	unsigned int		irqlogidx;
143 	u32			isrlog[32];
144 	u32			icrlog[32];
145 
146 	void __iomem		*reg_base;
147 	void __iomem		*reg_ibmr;
148 	void __iomem		*reg_idbr;
149 	void __iomem		*reg_icr;
150 	void __iomem		*reg_isr;
151 	void __iomem		*reg_isar;
152 
153 	unsigned long		iobase;
154 	unsigned long		iosize;
155 
156 	int			irq;
157 	unsigned int		use_pio :1;
158 	unsigned int		fast_mode :1;
159 	unsigned int		high_mode:1;
160 	unsigned char		master_code;
161 	unsigned long		rate;
162 	bool			highmode_enter;
163 };
164 
165 #define _IBMR(i2c)	((i2c)->reg_ibmr)
166 #define _IDBR(i2c)	((i2c)->reg_idbr)
167 #define _ICR(i2c)	((i2c)->reg_icr)
168 #define _ISR(i2c)	((i2c)->reg_isr)
169 #define _ISAR(i2c)	((i2c)->reg_isar)
170 
171 /*
172  * I2C Slave mode address
173  */
174 #define I2C_PXA_SLAVE_ADDR      0x1
175 
176 #ifdef DEBUG
177 
178 struct bits {
179 	u32	mask;
180 	const char *set;
181 	const char *unset;
182 };
183 #define PXA_BIT(m, s, u)	{ .mask = m, .set = s, .unset = u }
184 
185 static inline void
186 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
187 {
188 	printk("%s %08x: ", prefix, val);
189 	while (num--) {
190 		const char *str = val & bits->mask ? bits->set : bits->unset;
191 		if (str)
192 			printk("%s ", str);
193 		bits++;
194 	}
195 }
196 
197 static const struct bits isr_bits[] = {
198 	PXA_BIT(ISR_RWM,	"RX",		"TX"),
199 	PXA_BIT(ISR_ACKNAK,	"NAK",		"ACK"),
200 	PXA_BIT(ISR_UB,		"Bsy",		"Rdy"),
201 	PXA_BIT(ISR_IBB,	"BusBsy",	"BusRdy"),
202 	PXA_BIT(ISR_SSD,	"SlaveStop",	NULL),
203 	PXA_BIT(ISR_ALD,	"ALD",		NULL),
204 	PXA_BIT(ISR_ITE,	"TxEmpty",	NULL),
205 	PXA_BIT(ISR_IRF,	"RxFull",	NULL),
206 	PXA_BIT(ISR_GCAD,	"GenCall",	NULL),
207 	PXA_BIT(ISR_SAD,	"SlaveAddr",	NULL),
208 	PXA_BIT(ISR_BED,	"BusErr",	NULL),
209 };
210 
211 static void decode_ISR(unsigned int val)
212 {
213 	decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
214 	printk("\n");
215 }
216 
217 static const struct bits icr_bits[] = {
218 	PXA_BIT(ICR_START,  "START",	NULL),
219 	PXA_BIT(ICR_STOP,   "STOP",	NULL),
220 	PXA_BIT(ICR_ACKNAK, "ACKNAK",	NULL),
221 	PXA_BIT(ICR_TB,     "TB",	NULL),
222 	PXA_BIT(ICR_MA,     "MA",	NULL),
223 	PXA_BIT(ICR_SCLE,   "SCLE",	"scle"),
224 	PXA_BIT(ICR_IUE,    "IUE",	"iue"),
225 	PXA_BIT(ICR_GCD,    "GCD",	NULL),
226 	PXA_BIT(ICR_ITEIE,  "ITEIE",	NULL),
227 	PXA_BIT(ICR_IRFIE,  "IRFIE",	NULL),
228 	PXA_BIT(ICR_BEIE,   "BEIE",	NULL),
229 	PXA_BIT(ICR_SSDIE,  "SSDIE",	NULL),
230 	PXA_BIT(ICR_ALDIE,  "ALDIE",	NULL),
231 	PXA_BIT(ICR_SADIE,  "SADIE",	NULL),
232 	PXA_BIT(ICR_UR,     "UR",		"ur"),
233 };
234 
235 #ifdef CONFIG_I2C_PXA_SLAVE
236 static void decode_ICR(unsigned int val)
237 {
238 	decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
239 	printk("\n");
240 }
241 #endif
242 
243 static unsigned int i2c_debug = DEBUG;
244 
245 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
246 {
247 	dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
248 		readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
249 }
250 
251 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
252 
253 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
254 {
255 	unsigned int i;
256 	printk(KERN_ERR "i2c: error: %s\n", why);
257 	printk(KERN_ERR "i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
258 		i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
259 	printk(KERN_ERR "i2c: ICR: %08x ISR: %08x\n",
260 	       readl(_ICR(i2c)), readl(_ISR(i2c)));
261 	printk(KERN_DEBUG "i2c: log: ");
262 	for (i = 0; i < i2c->irqlogidx; i++)
263 		printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
264 	printk("\n");
265 }
266 
267 #else /* ifdef DEBUG */
268 
269 #define i2c_debug	0
270 
271 #define show_state(i2c) do { } while (0)
272 #define decode_ISR(val) do { } while (0)
273 #define decode_ICR(val) do { } while (0)
274 #define i2c_pxa_scream_blue_murder(i2c, why) do { } while (0)
275 
276 #endif /* ifdef DEBUG / else */
277 
278 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
279 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
280 
281 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
282 {
283 	return !(readl(_ICR(i2c)) & ICR_SCLE);
284 }
285 
286 static void i2c_pxa_abort(struct pxa_i2c *i2c)
287 {
288 	int i = 250;
289 
290 	if (i2c_pxa_is_slavemode(i2c)) {
291 		dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
292 		return;
293 	}
294 
295 	while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
296 		unsigned long icr = readl(_ICR(i2c));
297 
298 		icr &= ~ICR_START;
299 		icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
300 
301 		writel(icr, _ICR(i2c));
302 
303 		show_state(i2c);
304 
305 		mdelay(1);
306 		i --;
307 	}
308 
309 	writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
310 	       _ICR(i2c));
311 }
312 
313 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
314 {
315 	int timeout = DEF_TIMEOUT;
316 
317 	while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
318 		if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
319 			timeout += 4;
320 
321 		msleep(2);
322 		show_state(i2c);
323 	}
324 
325 	if (timeout < 0)
326 		show_state(i2c);
327 
328 	return timeout < 0 ? I2C_RETRY : 0;
329 }
330 
331 static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
332 {
333 	unsigned long timeout = jiffies + HZ*4;
334 
335 	while (time_before(jiffies, timeout)) {
336 		if (i2c_debug > 1)
337 			dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
338 				__func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
339 
340 		if (readl(_ISR(i2c)) & ISR_SAD) {
341 			if (i2c_debug > 0)
342 				dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
343 			goto out;
344 		}
345 
346 		/* wait for unit and bus being not busy, and we also do a
347 		 * quick check of the i2c lines themselves to ensure they've
348 		 * gone high...
349 		 */
350 		if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
351 			if (i2c_debug > 0)
352 				dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
353 			return 1;
354 		}
355 
356 		msleep(1);
357 	}
358 
359 	if (i2c_debug > 0)
360 		dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
361  out:
362 	return 0;
363 }
364 
365 static int i2c_pxa_set_master(struct pxa_i2c *i2c)
366 {
367 	if (i2c_debug)
368 		dev_dbg(&i2c->adap.dev, "setting to bus master\n");
369 
370 	if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
371 		dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
372 		if (!i2c_pxa_wait_master(i2c)) {
373 			dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
374 			return I2C_RETRY;
375 		}
376 	}
377 
378 	writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
379 	return 0;
380 }
381 
382 #ifdef CONFIG_I2C_PXA_SLAVE
383 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
384 {
385 	unsigned long timeout = jiffies + HZ*1;
386 
387 	/* wait for stop */
388 
389 	show_state(i2c);
390 
391 	while (time_before(jiffies, timeout)) {
392 		if (i2c_debug > 1)
393 			dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
394 				__func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
395 
396 		if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
397 		    (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
398 		    (readl(_ICR(i2c)) & ICR_SCLE) == 0) {
399 			if (i2c_debug > 1)
400 				dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
401 			return 1;
402 		}
403 
404 		msleep(1);
405 	}
406 
407 	if (i2c_debug > 0)
408 		dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
409 	return 0;
410 }
411 
412 /*
413  * clear the hold on the bus, and take of anything else
414  * that has been configured
415  */
416 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
417 {
418 	show_state(i2c);
419 
420 	if (errcode < 0) {
421 		udelay(100);   /* simple delay */
422 	} else {
423 		/* we need to wait for the stop condition to end */
424 
425 		/* if we where in stop, then clear... */
426 		if (readl(_ICR(i2c)) & ICR_STOP) {
427 			udelay(100);
428 			writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
429 		}
430 
431 		if (!i2c_pxa_wait_slave(i2c)) {
432 			dev_err(&i2c->adap.dev, "%s: wait timedout\n",
433 				__func__);
434 			return;
435 		}
436 	}
437 
438 	writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
439 	writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
440 
441 	if (i2c_debug) {
442 		dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
443 		decode_ICR(readl(_ICR(i2c)));
444 	}
445 }
446 #else
447 #define i2c_pxa_set_slave(i2c, err)	do { } while (0)
448 #endif
449 
450 static void i2c_pxa_reset(struct pxa_i2c *i2c)
451 {
452 	pr_debug("Resetting I2C Controller Unit\n");
453 
454 	/* abort any transfer currently under way */
455 	i2c_pxa_abort(i2c);
456 
457 	/* reset according to 9.8 */
458 	writel(ICR_UR, _ICR(i2c));
459 	writel(I2C_ISR_INIT, _ISR(i2c));
460 	writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
461 
462 	if (i2c->reg_isar)
463 		writel(i2c->slave_addr, _ISAR(i2c));
464 
465 	/* set control register values */
466 	writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
467 	writel(readl(_ICR(i2c)) | (i2c->high_mode ? ICR_HS : 0), _ICR(i2c));
468 
469 #ifdef CONFIG_I2C_PXA_SLAVE
470 	dev_info(&i2c->adap.dev, "Enabling slave mode\n");
471 	writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
472 #endif
473 
474 	i2c_pxa_set_slave(i2c, 0);
475 
476 	/* enable unit */
477 	writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
478 	udelay(100);
479 }
480 
481 
482 #ifdef CONFIG_I2C_PXA_SLAVE
483 /*
484  * PXA I2C Slave mode
485  */
486 
487 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
488 {
489 	if (isr & ISR_BED) {
490 		/* what should we do here? */
491 	} else {
492 		int ret = 0;
493 
494 		if (i2c->slave != NULL)
495 			ret = i2c->slave->read(i2c->slave->data);
496 
497 		writel(ret, _IDBR(i2c));
498 		writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));   /* allow next byte */
499 	}
500 }
501 
502 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
503 {
504 	unsigned int byte = readl(_IDBR(i2c));
505 
506 	if (i2c->slave != NULL)
507 		i2c->slave->write(i2c->slave->data, byte);
508 
509 	writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
510 }
511 
512 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
513 {
514 	int timeout;
515 
516 	if (i2c_debug > 0)
517 		dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
518 		       (isr & ISR_RWM) ? 'r' : 't');
519 
520 	if (i2c->slave != NULL)
521 		i2c->slave->event(i2c->slave->data,
522 				 (isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
523 
524 	/*
525 	 * slave could interrupt in the middle of us generating a
526 	 * start condition... if this happens, we'd better back off
527 	 * and stop holding the poor thing up
528 	 */
529 	writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
530 	writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
531 
532 	timeout = 0x10000;
533 
534 	while (1) {
535 		if ((readl(_IBMR(i2c)) & 2) == 2)
536 			break;
537 
538 		timeout--;
539 
540 		if (timeout <= 0) {
541 			dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
542 			break;
543 		}
544 	}
545 
546 	writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
547 }
548 
549 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
550 {
551 	if (i2c_debug > 2)
552 		dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
553 
554 	if (i2c->slave != NULL)
555 		i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
556 
557 	if (i2c_debug > 2)
558 		dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
559 
560 	/*
561 	 * If we have a master-mode message waiting,
562 	 * kick it off now that the slave has completed.
563 	 */
564 	if (i2c->msg)
565 		i2c_pxa_master_complete(i2c, I2C_RETRY);
566 }
567 #else
568 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
569 {
570 	if (isr & ISR_BED) {
571 		/* what should we do here? */
572 	} else {
573 		writel(0, _IDBR(i2c));
574 		writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
575 	}
576 }
577 
578 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
579 {
580 	writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
581 }
582 
583 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
584 {
585 	int timeout;
586 
587 	/*
588 	 * slave could interrupt in the middle of us generating a
589 	 * start condition... if this happens, we'd better back off
590 	 * and stop holding the poor thing up
591 	 */
592 	writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
593 	writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
594 
595 	timeout = 0x10000;
596 
597 	while (1) {
598 		if ((readl(_IBMR(i2c)) & 2) == 2)
599 			break;
600 
601 		timeout--;
602 
603 		if (timeout <= 0) {
604 			dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
605 			break;
606 		}
607 	}
608 
609 	writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
610 }
611 
612 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
613 {
614 	if (i2c->msg)
615 		i2c_pxa_master_complete(i2c, I2C_RETRY);
616 }
617 #endif
618 
619 /*
620  * PXA I2C Master mode
621  */
622 
623 static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
624 {
625 	unsigned int addr = (msg->addr & 0x7f) << 1;
626 
627 	if (msg->flags & I2C_M_RD)
628 		addr |= 1;
629 
630 	return addr;
631 }
632 
633 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
634 {
635 	u32 icr;
636 
637 	/*
638 	 * Step 1: target slave address into IDBR
639 	 */
640 	writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
641 
642 	/*
643 	 * Step 2: initiate the write.
644 	 */
645 	icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
646 	writel(icr | ICR_START | ICR_TB, _ICR(i2c));
647 }
648 
649 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
650 {
651 	u32 icr;
652 
653 	/*
654 	 * Clear the STOP and ACK flags
655 	 */
656 	icr = readl(_ICR(i2c));
657 	icr &= ~(ICR_STOP | ICR_ACKNAK);
658 	writel(icr, _ICR(i2c));
659 }
660 
661 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
662 {
663 	/* make timeout the same as for interrupt based functions */
664 	long timeout = 2 * DEF_TIMEOUT;
665 
666 	/*
667 	 * Wait for the bus to become free.
668 	 */
669 	while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
670 		udelay(1000);
671 		show_state(i2c);
672 	}
673 
674 	if (timeout < 0) {
675 		show_state(i2c);
676 		dev_err(&i2c->adap.dev,
677 			"i2c_pxa: timeout waiting for bus free\n");
678 		return I2C_RETRY;
679 	}
680 
681 	/*
682 	 * Set master mode.
683 	 */
684 	writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
685 
686 	return 0;
687 }
688 
689 /*
690  * PXA I2C send master code
691  * 1. Load master code to IDBR and send it.
692  *    Note for HS mode, set ICR [GPIOEN].
693  * 2. Wait until win arbitration.
694  */
695 static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c)
696 {
697 	u32 icr;
698 	long timeout;
699 
700 	spin_lock_irq(&i2c->lock);
701 	i2c->highmode_enter = true;
702 	writel(i2c->master_code, _IDBR(i2c));
703 
704 	icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
705 	icr |= ICR_GPIOEN | ICR_START | ICR_TB | ICR_ITEIE;
706 	writel(icr, _ICR(i2c));
707 
708 	spin_unlock_irq(&i2c->lock);
709 	timeout = wait_event_timeout(i2c->wait,
710 			i2c->highmode_enter == false, HZ * 1);
711 
712 	i2c->highmode_enter = false;
713 
714 	return (timeout == 0) ? I2C_RETRY : 0;
715 }
716 
717 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
718 			       struct i2c_msg *msg, int num)
719 {
720 	unsigned long timeout = 500000; /* 5 seconds */
721 	int ret = 0;
722 
723 	ret = i2c_pxa_pio_set_master(i2c);
724 	if (ret)
725 		goto out;
726 
727 	i2c->msg = msg;
728 	i2c->msg_num = num;
729 	i2c->msg_idx = 0;
730 	i2c->msg_ptr = 0;
731 	i2c->irqlogidx = 0;
732 
733 	i2c_pxa_start_message(i2c);
734 
735 	while (i2c->msg_num > 0 && --timeout) {
736 		i2c_pxa_handler(0, i2c);
737 		udelay(10);
738 	}
739 
740 	i2c_pxa_stop_message(i2c);
741 
742 	/*
743 	 * We place the return code in i2c->msg_idx.
744 	 */
745 	ret = i2c->msg_idx;
746 
747 out:
748 	if (timeout == 0)
749 		i2c_pxa_scream_blue_murder(i2c, "timeout");
750 
751 	return ret;
752 }
753 
754 /*
755  * We are protected by the adapter bus mutex.
756  */
757 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
758 {
759 	long timeout;
760 	int ret;
761 
762 	/*
763 	 * Wait for the bus to become free.
764 	 */
765 	ret = i2c_pxa_wait_bus_not_busy(i2c);
766 	if (ret) {
767 		dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
768 		goto out;
769 	}
770 
771 	/*
772 	 * Set master mode.
773 	 */
774 	ret = i2c_pxa_set_master(i2c);
775 	if (ret) {
776 		dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
777 		goto out;
778 	}
779 
780 	if (i2c->high_mode) {
781 		ret = i2c_pxa_send_mastercode(i2c);
782 		if (ret) {
783 			dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
784 			goto out;
785 			}
786 	}
787 
788 	spin_lock_irq(&i2c->lock);
789 
790 	i2c->msg = msg;
791 	i2c->msg_num = num;
792 	i2c->msg_idx = 0;
793 	i2c->msg_ptr = 0;
794 	i2c->irqlogidx = 0;
795 
796 	i2c_pxa_start_message(i2c);
797 
798 	spin_unlock_irq(&i2c->lock);
799 
800 	/*
801 	 * The rest of the processing occurs in the interrupt handler.
802 	 */
803 	timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
804 	i2c_pxa_stop_message(i2c);
805 
806 	/*
807 	 * We place the return code in i2c->msg_idx.
808 	 */
809 	ret = i2c->msg_idx;
810 
811 	if (!timeout && i2c->msg_num) {
812 		i2c_pxa_scream_blue_murder(i2c, "timeout");
813 		ret = I2C_RETRY;
814 	}
815 
816  out:
817 	return ret;
818 }
819 
820 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
821 			    struct i2c_msg msgs[], int num)
822 {
823 	struct pxa_i2c *i2c = adap->algo_data;
824 	int ret, i;
825 
826 	/* If the I2C controller is disabled we need to reset it
827 	  (probably due to a suspend/resume destroying state). We do
828 	  this here as we can then avoid worrying about resuming the
829 	  controller before its users. */
830 	if (!(readl(_ICR(i2c)) & ICR_IUE))
831 		i2c_pxa_reset(i2c);
832 
833 	for (i = adap->retries; i >= 0; i--) {
834 		ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
835 		if (ret != I2C_RETRY)
836 			goto out;
837 
838 		if (i2c_debug)
839 			dev_dbg(&adap->dev, "Retrying transmission\n");
840 		udelay(100);
841 	}
842 	i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
843 	ret = -EREMOTEIO;
844  out:
845 	i2c_pxa_set_slave(i2c, ret);
846 	return ret;
847 }
848 
849 /*
850  * i2c_pxa_master_complete - complete the message and wake up.
851  */
852 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
853 {
854 	i2c->msg_ptr = 0;
855 	i2c->msg = NULL;
856 	i2c->msg_idx ++;
857 	i2c->msg_num = 0;
858 	if (ret)
859 		i2c->msg_idx = ret;
860 	if (!i2c->use_pio)
861 		wake_up(&i2c->wait);
862 }
863 
864 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
865 {
866 	u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
867 
868  again:
869 	/*
870 	 * If ISR_ALD is set, we lost arbitration.
871 	 */
872 	if (isr & ISR_ALD) {
873 		/*
874 		 * Do we need to do anything here?  The PXA docs
875 		 * are vague about what happens.
876 		 */
877 		i2c_pxa_scream_blue_murder(i2c, "ALD set");
878 
879 		/*
880 		 * We ignore this error.  We seem to see spurious ALDs
881 		 * for seemingly no reason.  If we handle them as I think
882 		 * they should, we end up causing an I2C error, which
883 		 * is painful for some systems.
884 		 */
885 		return; /* ignore */
886 	}
887 
888 	if (isr & ISR_BED) {
889 		int ret = BUS_ERROR;
890 
891 		/*
892 		 * I2C bus error - either the device NAK'd us, or
893 		 * something more serious happened.  If we were NAK'd
894 		 * on the initial address phase, we can retry.
895 		 */
896 		if (isr & ISR_ACKNAK) {
897 			if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
898 				ret = I2C_RETRY;
899 			else
900 				ret = XFER_NAKED;
901 		}
902 		i2c_pxa_master_complete(i2c, ret);
903 	} else if (isr & ISR_RWM) {
904 		/*
905 		 * Read mode.  We have just sent the address byte, and
906 		 * now we must initiate the transfer.
907 		 */
908 		if (i2c->msg_ptr == i2c->msg->len - 1 &&
909 		    i2c->msg_idx == i2c->msg_num - 1)
910 			icr |= ICR_STOP | ICR_ACKNAK;
911 
912 		icr |= ICR_ALDIE | ICR_TB;
913 	} else if (i2c->msg_ptr < i2c->msg->len) {
914 		/*
915 		 * Write mode.  Write the next data byte.
916 		 */
917 		writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
918 
919 		icr |= ICR_ALDIE | ICR_TB;
920 
921 		/*
922 		 * If this is the last byte of the last message, send
923 		 * a STOP.
924 		 */
925 		if (i2c->msg_ptr == i2c->msg->len &&
926 		    i2c->msg_idx == i2c->msg_num - 1)
927 			icr |= ICR_STOP;
928 	} else if (i2c->msg_idx < i2c->msg_num - 1) {
929 		/*
930 		 * Next segment of the message.
931 		 */
932 		i2c->msg_ptr = 0;
933 		i2c->msg_idx ++;
934 		i2c->msg++;
935 
936 		/*
937 		 * If we aren't doing a repeated start and address,
938 		 * go back and try to send the next byte.  Note that
939 		 * we do not support switching the R/W direction here.
940 		 */
941 		if (i2c->msg->flags & I2C_M_NOSTART)
942 			goto again;
943 
944 		/*
945 		 * Write the next address.
946 		 */
947 		writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
948 
949 		/*
950 		 * And trigger a repeated start, and send the byte.
951 		 */
952 		icr &= ~ICR_ALDIE;
953 		icr |= ICR_START | ICR_TB;
954 	} else {
955 		if (i2c->msg->len == 0) {
956 			/*
957 			 * Device probes have a message length of zero
958 			 * and need the bus to be reset before it can
959 			 * be used again.
960 			 */
961 			i2c_pxa_reset(i2c);
962 		}
963 		i2c_pxa_master_complete(i2c, 0);
964 	}
965 
966 	i2c->icrlog[i2c->irqlogidx-1] = icr;
967 
968 	writel(icr, _ICR(i2c));
969 	show_state(i2c);
970 }
971 
972 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
973 {
974 	u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
975 
976 	/*
977 	 * Read the byte.
978 	 */
979 	i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
980 
981 	if (i2c->msg_ptr < i2c->msg->len) {
982 		/*
983 		 * If this is the last byte of the last
984 		 * message, send a STOP.
985 		 */
986 		if (i2c->msg_ptr == i2c->msg->len - 1)
987 			icr |= ICR_STOP | ICR_ACKNAK;
988 
989 		icr |= ICR_ALDIE | ICR_TB;
990 	} else {
991 		i2c_pxa_master_complete(i2c, 0);
992 	}
993 
994 	i2c->icrlog[i2c->irqlogidx-1] = icr;
995 
996 	writel(icr, _ICR(i2c));
997 }
998 
999 #define VALID_INT_SOURCE	(ISR_SSD | ISR_ALD | ISR_ITE | ISR_IRF | \
1000 				ISR_SAD | ISR_BED)
1001 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
1002 {
1003 	struct pxa_i2c *i2c = dev_id;
1004 	u32 isr = readl(_ISR(i2c));
1005 
1006 	if (!(isr & VALID_INT_SOURCE))
1007 		return IRQ_NONE;
1008 
1009 	if (i2c_debug > 2 && 0) {
1010 		dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
1011 			__func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
1012 		decode_ISR(isr);
1013 	}
1014 
1015 	if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
1016 		i2c->isrlog[i2c->irqlogidx++] = isr;
1017 
1018 	show_state(i2c);
1019 
1020 	/*
1021 	 * Always clear all pending IRQs.
1022 	 */
1023 	writel(isr & VALID_INT_SOURCE, _ISR(i2c));
1024 
1025 	if (isr & ISR_SAD)
1026 		i2c_pxa_slave_start(i2c, isr);
1027 	if (isr & ISR_SSD)
1028 		i2c_pxa_slave_stop(i2c);
1029 
1030 	if (i2c_pxa_is_slavemode(i2c)) {
1031 		if (isr & ISR_ITE)
1032 			i2c_pxa_slave_txempty(i2c, isr);
1033 		if (isr & ISR_IRF)
1034 			i2c_pxa_slave_rxfull(i2c, isr);
1035 	} else if (i2c->msg && (!i2c->highmode_enter)) {
1036 		if (isr & ISR_ITE)
1037 			i2c_pxa_irq_txempty(i2c, isr);
1038 		if (isr & ISR_IRF)
1039 			i2c_pxa_irq_rxfull(i2c, isr);
1040 	} else if ((isr & ISR_ITE) && i2c->highmode_enter) {
1041 		i2c->highmode_enter = false;
1042 		wake_up(&i2c->wait);
1043 	} else {
1044 		i2c_pxa_scream_blue_murder(i2c, "spurious irq");
1045 	}
1046 
1047 	return IRQ_HANDLED;
1048 }
1049 
1050 
1051 static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
1052 {
1053 	struct pxa_i2c *i2c = adap->algo_data;
1054 	int ret, i;
1055 
1056 	for (i = adap->retries; i >= 0; i--) {
1057 		ret = i2c_pxa_do_xfer(i2c, msgs, num);
1058 		if (ret != I2C_RETRY)
1059 			goto out;
1060 
1061 		if (i2c_debug)
1062 			dev_dbg(&adap->dev, "Retrying transmission\n");
1063 		udelay(100);
1064 	}
1065 	i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
1066 	ret = -EREMOTEIO;
1067  out:
1068 	i2c_pxa_set_slave(i2c, ret);
1069 	return ret;
1070 }
1071 
1072 static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
1073 {
1074 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
1075 }
1076 
1077 static const struct i2c_algorithm i2c_pxa_algorithm = {
1078 	.master_xfer	= i2c_pxa_xfer,
1079 	.functionality	= i2c_pxa_functionality,
1080 };
1081 
1082 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
1083 	.master_xfer	= i2c_pxa_pio_xfer,
1084 	.functionality	= i2c_pxa_functionality,
1085 };
1086 
1087 static const struct of_device_id i2c_pxa_dt_ids[] = {
1088 	{ .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX },
1089 	{ .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX },
1090 	{ .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA2XX },
1091 	{}
1092 };
1093 MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
1094 
1095 static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
1096 			    enum pxa_i2c_types *i2c_types)
1097 {
1098 	struct device_node *np = pdev->dev.of_node;
1099 	const struct of_device_id *of_id =
1100 			of_match_device(i2c_pxa_dt_ids, &pdev->dev);
1101 
1102 	if (!of_id)
1103 		return 1;
1104 
1105 	/* For device tree we always use the dynamic or alias-assigned ID */
1106 	i2c->adap.nr = -1;
1107 
1108 	if (of_get_property(np, "mrvl,i2c-polling", NULL))
1109 		i2c->use_pio = 1;
1110 	if (of_get_property(np, "mrvl,i2c-fast-mode", NULL))
1111 		i2c->fast_mode = 1;
1112 	*i2c_types = (u32)(of_id->data);
1113 	return 0;
1114 }
1115 
1116 static int i2c_pxa_probe_pdata(struct platform_device *pdev,
1117 			       struct pxa_i2c *i2c,
1118 			       enum pxa_i2c_types *i2c_types)
1119 {
1120 	struct i2c_pxa_platform_data *plat = dev_get_platdata(&pdev->dev);
1121 	const struct platform_device_id *id = platform_get_device_id(pdev);
1122 
1123 	*i2c_types = id->driver_data;
1124 	if (plat) {
1125 		i2c->use_pio = plat->use_pio;
1126 		i2c->fast_mode = plat->fast_mode;
1127 		i2c->high_mode = plat->high_mode;
1128 		i2c->master_code = plat->master_code;
1129 		if (!i2c->master_code)
1130 			i2c->master_code = 0xe;
1131 		i2c->rate = plat->rate;
1132 	}
1133 	return 0;
1134 }
1135 
1136 static int i2c_pxa_probe(struct platform_device *dev)
1137 {
1138 	struct i2c_pxa_platform_data *plat = dev_get_platdata(&dev->dev);
1139 	enum pxa_i2c_types i2c_type;
1140 	struct pxa_i2c *i2c;
1141 	struct resource *res = NULL;
1142 	int ret, irq;
1143 
1144 	i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
1145 	if (!i2c) {
1146 		ret = -ENOMEM;
1147 		goto emalloc;
1148 	}
1149 
1150 	/* Default adapter num to device id; i2c_pxa_probe_dt can override. */
1151 	i2c->adap.nr = dev->id;
1152 
1153 	ret = i2c_pxa_probe_dt(dev, i2c, &i2c_type);
1154 	if (ret > 0)
1155 		ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
1156 	if (ret < 0)
1157 		goto eclk;
1158 
1159 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
1160 	irq = platform_get_irq(dev, 0);
1161 	if (res == NULL || irq < 0) {
1162 		ret = -ENODEV;
1163 		goto eclk;
1164 	}
1165 
1166 	if (!request_mem_region(res->start, resource_size(res), res->name)) {
1167 		ret = -ENOMEM;
1168 		goto eclk;
1169 	}
1170 
1171 	i2c->adap.owner   = THIS_MODULE;
1172 	i2c->adap.retries = 5;
1173 
1174 	spin_lock_init(&i2c->lock);
1175 	init_waitqueue_head(&i2c->wait);
1176 
1177 	strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
1178 
1179 	i2c->clk = clk_get(&dev->dev, NULL);
1180 	if (IS_ERR(i2c->clk)) {
1181 		ret = PTR_ERR(i2c->clk);
1182 		goto eclk;
1183 	}
1184 
1185 	i2c->reg_base = ioremap(res->start, resource_size(res));
1186 	if (!i2c->reg_base) {
1187 		ret = -EIO;
1188 		goto eremap;
1189 	}
1190 
1191 	i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
1192 	i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr;
1193 	i2c->reg_icr = i2c->reg_base + pxa_reg_layout[i2c_type].icr;
1194 	i2c->reg_isr = i2c->reg_base + pxa_reg_layout[i2c_type].isr;
1195 	if (i2c_type != REGS_CE4100)
1196 		i2c->reg_isar = i2c->reg_base + pxa_reg_layout[i2c_type].isar;
1197 
1198 	i2c->iobase = res->start;
1199 	i2c->iosize = resource_size(res);
1200 
1201 	i2c->irq = irq;
1202 
1203 	i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
1204 	i2c->highmode_enter = false;
1205 
1206 	if (plat) {
1207 #ifdef CONFIG_I2C_PXA_SLAVE
1208 		i2c->slave_addr = plat->slave_addr;
1209 		i2c->slave = plat->slave;
1210 #endif
1211 		i2c->adap.class = plat->class;
1212 	}
1213 
1214 	if (i2c->high_mode) {
1215 		if (i2c->rate) {
1216 			clk_set_rate(i2c->clk, i2c->rate);
1217 			pr_info("i2c: <%s> set rate to %ld\n",
1218 				i2c->adap.name, clk_get_rate(i2c->clk));
1219 		} else
1220 			pr_warn("i2c: <%s> clock rate not set\n",
1221 				i2c->adap.name);
1222 	}
1223 
1224 	clk_prepare_enable(i2c->clk);
1225 
1226 	if (i2c->use_pio) {
1227 		i2c->adap.algo = &i2c_pxa_pio_algorithm;
1228 	} else {
1229 		i2c->adap.algo = &i2c_pxa_algorithm;
1230 		ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
1231 				  dev_name(&dev->dev), i2c);
1232 		if (ret)
1233 			goto ereqirq;
1234 	}
1235 
1236 	i2c_pxa_reset(i2c);
1237 
1238 	i2c->adap.algo_data = i2c;
1239 	i2c->adap.dev.parent = &dev->dev;
1240 #ifdef CONFIG_OF
1241 	i2c->adap.dev.of_node = dev->dev.of_node;
1242 #endif
1243 
1244 	ret = i2c_add_numbered_adapter(&i2c->adap);
1245 	if (ret < 0) {
1246 		printk(KERN_INFO "I2C: Failed to add bus\n");
1247 		goto eadapt;
1248 	}
1249 
1250 	platform_set_drvdata(dev, i2c);
1251 
1252 #ifdef CONFIG_I2C_PXA_SLAVE
1253 	printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
1254 	       dev_name(&i2c->adap.dev), i2c->slave_addr);
1255 #else
1256 	printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
1257 	       dev_name(&i2c->adap.dev));
1258 #endif
1259 	return 0;
1260 
1261 eadapt:
1262 	if (!i2c->use_pio)
1263 		free_irq(irq, i2c);
1264 ereqirq:
1265 	clk_disable_unprepare(i2c->clk);
1266 	iounmap(i2c->reg_base);
1267 eremap:
1268 	clk_put(i2c->clk);
1269 eclk:
1270 	kfree(i2c);
1271 emalloc:
1272 	release_mem_region(res->start, resource_size(res));
1273 	return ret;
1274 }
1275 
1276 static int i2c_pxa_remove(struct platform_device *dev)
1277 {
1278 	struct pxa_i2c *i2c = platform_get_drvdata(dev);
1279 
1280 	i2c_del_adapter(&i2c->adap);
1281 	if (!i2c->use_pio)
1282 		free_irq(i2c->irq, i2c);
1283 
1284 	clk_disable_unprepare(i2c->clk);
1285 	clk_put(i2c->clk);
1286 
1287 	iounmap(i2c->reg_base);
1288 	release_mem_region(i2c->iobase, i2c->iosize);
1289 	kfree(i2c);
1290 
1291 	return 0;
1292 }
1293 
1294 #ifdef CONFIG_PM
1295 static int i2c_pxa_suspend_noirq(struct device *dev)
1296 {
1297 	struct platform_device *pdev = to_platform_device(dev);
1298 	struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1299 
1300 	clk_disable(i2c->clk);
1301 
1302 	return 0;
1303 }
1304 
1305 static int i2c_pxa_resume_noirq(struct device *dev)
1306 {
1307 	struct platform_device *pdev = to_platform_device(dev);
1308 	struct pxa_i2c *i2c = platform_get_drvdata(pdev);
1309 
1310 	clk_enable(i2c->clk);
1311 	i2c_pxa_reset(i2c);
1312 
1313 	return 0;
1314 }
1315 
1316 static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
1317 	.suspend_noirq = i2c_pxa_suspend_noirq,
1318 	.resume_noirq = i2c_pxa_resume_noirq,
1319 };
1320 
1321 #define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
1322 #else
1323 #define I2C_PXA_DEV_PM_OPS NULL
1324 #endif
1325 
1326 static struct platform_driver i2c_pxa_driver = {
1327 	.probe		= i2c_pxa_probe,
1328 	.remove		= i2c_pxa_remove,
1329 	.driver		= {
1330 		.name	= "pxa2xx-i2c",
1331 		.owner	= THIS_MODULE,
1332 		.pm	= I2C_PXA_DEV_PM_OPS,
1333 		.of_match_table = i2c_pxa_dt_ids,
1334 	},
1335 	.id_table	= i2c_pxa_id_table,
1336 };
1337 
1338 static int __init i2c_adap_pxa_init(void)
1339 {
1340 	return platform_driver_register(&i2c_pxa_driver);
1341 }
1342 
1343 static void __exit i2c_adap_pxa_exit(void)
1344 {
1345 	platform_driver_unregister(&i2c_pxa_driver);
1346 }
1347 
1348 MODULE_LICENSE("GPL");
1349 MODULE_ALIAS("platform:pxa2xx-i2c");
1350 
1351 subsys_initcall(i2c_adap_pxa_init);
1352 module_exit(i2c_adap_pxa_exit);
1353