xref: /linux/drivers/i2c/busses/i2c-omap.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
1 /*
2  * TI OMAP I2C master mode driver
3  *
4  * Copyright (C) 2003 MontaVista Software, Inc.
5  * Copyright (C) 2005 Nokia Corporation
6  * Copyright (C) 2004 - 2007 Texas Instruments.
7  *
8  * Originally written by MontaVista Software, Inc.
9  * Additional contributions by:
10  *	Tony Lindgren <tony@atomide.com>
11  *	Imre Deak <imre.deak@nokia.com>
12  *	Juha Yrjölä <juha.yrjola@solidboot.com>
13  *	Syed Khasim <x0khasim@ti.com>
14  *	Nishant Menon <nm@ti.com>
15  *
16  * This program is free software; you can redistribute it and/or modify
17  * it under the terms of the GNU General Public License as published by
18  * the Free Software Foundation; either version 2 of the License, or
19  * (at your option) any later version.
20  *
21  * This program is distributed in the hope that it will be useful,
22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24  * GNU General Public License for more details.
25  *
26  * You should have received a copy of the GNU General Public License
27  * along with this program; if not, write to the Free Software
28  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29  */
30 
31 #include <linux/module.h>
32 #include <linux/delay.h>
33 #include <linux/i2c.h>
34 #include <linux/err.h>
35 #include <linux/interrupt.h>
36 #include <linux/completion.h>
37 #include <linux/platform_device.h>
38 #include <linux/clk.h>
39 #include <linux/io.h>
40 #include <linux/of.h>
41 #include <linux/of_i2c.h>
42 #include <linux/of_device.h>
43 #include <linux/slab.h>
44 #include <linux/i2c-omap.h>
45 #include <linux/pm_runtime.h>
46 
47 /* I2C controller revisions */
48 #define OMAP_I2C_OMAP1_REV_2		0x20
49 
50 /* I2C controller revisions present on specific hardware */
51 #define OMAP_I2C_REV_ON_2430		0x36
52 #define OMAP_I2C_REV_ON_3430_3530	0x3C
53 #define OMAP_I2C_REV_ON_3630_4430	0x40
54 
55 /* timeout waiting for the controller to respond */
56 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
57 
58 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
59 enum {
60 	OMAP_I2C_REV_REG = 0,
61 	OMAP_I2C_IE_REG,
62 	OMAP_I2C_STAT_REG,
63 	OMAP_I2C_IV_REG,
64 	OMAP_I2C_WE_REG,
65 	OMAP_I2C_SYSS_REG,
66 	OMAP_I2C_BUF_REG,
67 	OMAP_I2C_CNT_REG,
68 	OMAP_I2C_DATA_REG,
69 	OMAP_I2C_SYSC_REG,
70 	OMAP_I2C_CON_REG,
71 	OMAP_I2C_OA_REG,
72 	OMAP_I2C_SA_REG,
73 	OMAP_I2C_PSC_REG,
74 	OMAP_I2C_SCLL_REG,
75 	OMAP_I2C_SCLH_REG,
76 	OMAP_I2C_SYSTEST_REG,
77 	OMAP_I2C_BUFSTAT_REG,
78 	/* only on OMAP4430 */
79 	OMAP_I2C_IP_V2_REVNB_LO,
80 	OMAP_I2C_IP_V2_REVNB_HI,
81 	OMAP_I2C_IP_V2_IRQSTATUS_RAW,
82 	OMAP_I2C_IP_V2_IRQENABLE_SET,
83 	OMAP_I2C_IP_V2_IRQENABLE_CLR,
84 };
85 
86 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
87 #define OMAP_I2C_IE_XDR		(1 << 14)	/* TX Buffer drain int enable */
88 #define OMAP_I2C_IE_RDR		(1 << 13)	/* RX Buffer drain int enable */
89 #define OMAP_I2C_IE_XRDY	(1 << 4)	/* TX data ready int enable */
90 #define OMAP_I2C_IE_RRDY	(1 << 3)	/* RX data ready int enable */
91 #define OMAP_I2C_IE_ARDY	(1 << 2)	/* Access ready int enable */
92 #define OMAP_I2C_IE_NACK	(1 << 1)	/* No ack interrupt enable */
93 #define OMAP_I2C_IE_AL		(1 << 0)	/* Arbitration lost int ena */
94 
95 /* I2C Status Register (OMAP_I2C_STAT): */
96 #define OMAP_I2C_STAT_XDR	(1 << 14)	/* TX Buffer draining */
97 #define OMAP_I2C_STAT_RDR	(1 << 13)	/* RX Buffer draining */
98 #define OMAP_I2C_STAT_BB	(1 << 12)	/* Bus busy */
99 #define OMAP_I2C_STAT_ROVR	(1 << 11)	/* Receive overrun */
100 #define OMAP_I2C_STAT_XUDF	(1 << 10)	/* Transmit underflow */
101 #define OMAP_I2C_STAT_AAS	(1 << 9)	/* Address as slave */
102 #define OMAP_I2C_STAT_AD0	(1 << 8)	/* Address zero */
103 #define OMAP_I2C_STAT_XRDY	(1 << 4)	/* Transmit data ready */
104 #define OMAP_I2C_STAT_RRDY	(1 << 3)	/* Receive data ready */
105 #define OMAP_I2C_STAT_ARDY	(1 << 2)	/* Register access ready */
106 #define OMAP_I2C_STAT_NACK	(1 << 1)	/* No ack interrupt enable */
107 #define OMAP_I2C_STAT_AL	(1 << 0)	/* Arbitration lost int ena */
108 
109 /* I2C WE wakeup enable register */
110 #define OMAP_I2C_WE_XDR_WE	(1 << 14)	/* TX drain wakup */
111 #define OMAP_I2C_WE_RDR_WE	(1 << 13)	/* RX drain wakeup */
112 #define OMAP_I2C_WE_AAS_WE	(1 << 9)	/* Address as slave wakeup*/
113 #define OMAP_I2C_WE_BF_WE	(1 << 8)	/* Bus free wakeup */
114 #define OMAP_I2C_WE_STC_WE	(1 << 6)	/* Start condition wakeup */
115 #define OMAP_I2C_WE_GC_WE	(1 << 5)	/* General call wakeup */
116 #define OMAP_I2C_WE_DRDY_WE	(1 << 3)	/* TX/RX data ready wakeup */
117 #define OMAP_I2C_WE_ARDY_WE	(1 << 2)	/* Reg access ready wakeup */
118 #define OMAP_I2C_WE_NACK_WE	(1 << 1)	/* No acknowledgment wakeup */
119 #define OMAP_I2C_WE_AL_WE	(1 << 0)	/* Arbitration lost wakeup */
120 
121 #define OMAP_I2C_WE_ALL		(OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
122 				OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
123 				OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
124 				OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
125 				OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
126 
127 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
128 #define OMAP_I2C_BUF_RDMA_EN	(1 << 15)	/* RX DMA channel enable */
129 #define OMAP_I2C_BUF_RXFIF_CLR	(1 << 14)	/* RX FIFO Clear */
130 #define OMAP_I2C_BUF_XDMA_EN	(1 << 7)	/* TX DMA channel enable */
131 #define OMAP_I2C_BUF_TXFIF_CLR	(1 << 6)	/* TX FIFO Clear */
132 
133 /* I2C Configuration Register (OMAP_I2C_CON): */
134 #define OMAP_I2C_CON_EN		(1 << 15)	/* I2C module enable */
135 #define OMAP_I2C_CON_BE		(1 << 14)	/* Big endian mode */
136 #define OMAP_I2C_CON_OPMODE_HS	(1 << 12)	/* High Speed support */
137 #define OMAP_I2C_CON_STB	(1 << 11)	/* Start byte mode (master) */
138 #define OMAP_I2C_CON_MST	(1 << 10)	/* Master/slave mode */
139 #define OMAP_I2C_CON_TRX	(1 << 9)	/* TX/RX mode (master only) */
140 #define OMAP_I2C_CON_XA		(1 << 8)	/* Expand address */
141 #define OMAP_I2C_CON_RM		(1 << 2)	/* Repeat mode (master only) */
142 #define OMAP_I2C_CON_STP	(1 << 1)	/* Stop cond (master only) */
143 #define OMAP_I2C_CON_STT	(1 << 0)	/* Start condition (master) */
144 
145 /* I2C SCL time value when Master */
146 #define OMAP_I2C_SCLL_HSSCLL	8
147 #define OMAP_I2C_SCLH_HSSCLH	8
148 
149 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
150 #ifdef DEBUG
151 #define OMAP_I2C_SYSTEST_ST_EN		(1 << 15)	/* System test enable */
152 #define OMAP_I2C_SYSTEST_FREE		(1 << 14)	/* Free running mode */
153 #define OMAP_I2C_SYSTEST_TMODE_MASK	(3 << 12)	/* Test mode select */
154 #define OMAP_I2C_SYSTEST_TMODE_SHIFT	(12)		/* Test mode select */
155 #define OMAP_I2C_SYSTEST_SCL_I		(1 << 3)	/* SCL line sense in */
156 #define OMAP_I2C_SYSTEST_SCL_O		(1 << 2)	/* SCL line drive out */
157 #define OMAP_I2C_SYSTEST_SDA_I		(1 << 1)	/* SDA line sense in */
158 #define OMAP_I2C_SYSTEST_SDA_O		(1 << 0)	/* SDA line drive out */
159 #endif
160 
161 /* OCP_SYSSTATUS bit definitions */
162 #define SYSS_RESETDONE_MASK		(1 << 0)
163 
164 /* OCP_SYSCONFIG bit definitions */
165 #define SYSC_CLOCKACTIVITY_MASK		(0x3 << 8)
166 #define SYSC_SIDLEMODE_MASK		(0x3 << 3)
167 #define SYSC_ENAWAKEUP_MASK		(1 << 2)
168 #define SYSC_SOFTRESET_MASK		(1 << 1)
169 #define SYSC_AUTOIDLE_MASK		(1 << 0)
170 
171 #define SYSC_IDLEMODE_SMART		0x2
172 #define SYSC_CLOCKACTIVITY_FCLK		0x2
173 
174 /* Errata definitions */
175 #define I2C_OMAP_ERRATA_I207		(1 << 0)
176 #define I2C_OMAP_ERRATA_I462		(1 << 1)
177 
178 struct omap_i2c_dev {
179 	struct device		*dev;
180 	void __iomem		*base;		/* virtual */
181 	int			irq;
182 	int			reg_shift;      /* bit shift for I2C register addresses */
183 	struct completion	cmd_complete;
184 	struct resource		*ioarea;
185 	u32			latency;	/* maximum mpu wkup latency */
186 	void			(*set_mpu_wkup_lat)(struct device *dev,
187 						    long latency);
188 	u32			speed;		/* Speed of bus in kHz */
189 	u32			dtrev;		/* extra revision from DT */
190 	u32			flags;
191 	u16			cmd_err;
192 	u8			*buf;
193 	u8			*regs;
194 	size_t			buf_len;
195 	struct i2c_adapter	adapter;
196 	u8			fifo_size;	/* use as flag and value
197 						 * fifo_size==0 implies no fifo
198 						 * if set, should be trsh+1
199 						 */
200 	u8			rev;
201 	unsigned		b_hw:1;		/* bad h/w fixes */
202 	u16			iestate;	/* Saved interrupt register */
203 	u16			pscstate;
204 	u16			scllstate;
205 	u16			sclhstate;
206 	u16			bufstate;
207 	u16			syscstate;
208 	u16			westate;
209 	u16			errata;
210 };
211 
212 static const u8 reg_map_ip_v1[] = {
213 	[OMAP_I2C_REV_REG] = 0x00,
214 	[OMAP_I2C_IE_REG] = 0x01,
215 	[OMAP_I2C_STAT_REG] = 0x02,
216 	[OMAP_I2C_IV_REG] = 0x03,
217 	[OMAP_I2C_WE_REG] = 0x03,
218 	[OMAP_I2C_SYSS_REG] = 0x04,
219 	[OMAP_I2C_BUF_REG] = 0x05,
220 	[OMAP_I2C_CNT_REG] = 0x06,
221 	[OMAP_I2C_DATA_REG] = 0x07,
222 	[OMAP_I2C_SYSC_REG] = 0x08,
223 	[OMAP_I2C_CON_REG] = 0x09,
224 	[OMAP_I2C_OA_REG] = 0x0a,
225 	[OMAP_I2C_SA_REG] = 0x0b,
226 	[OMAP_I2C_PSC_REG] = 0x0c,
227 	[OMAP_I2C_SCLL_REG] = 0x0d,
228 	[OMAP_I2C_SCLH_REG] = 0x0e,
229 	[OMAP_I2C_SYSTEST_REG] = 0x0f,
230 	[OMAP_I2C_BUFSTAT_REG] = 0x10,
231 };
232 
233 static const u8 reg_map_ip_v2[] = {
234 	[OMAP_I2C_REV_REG] = 0x04,
235 	[OMAP_I2C_IE_REG] = 0x2c,
236 	[OMAP_I2C_STAT_REG] = 0x28,
237 	[OMAP_I2C_IV_REG] = 0x34,
238 	[OMAP_I2C_WE_REG] = 0x34,
239 	[OMAP_I2C_SYSS_REG] = 0x90,
240 	[OMAP_I2C_BUF_REG] = 0x94,
241 	[OMAP_I2C_CNT_REG] = 0x98,
242 	[OMAP_I2C_DATA_REG] = 0x9c,
243 	[OMAP_I2C_SYSC_REG] = 0x10,
244 	[OMAP_I2C_CON_REG] = 0xa4,
245 	[OMAP_I2C_OA_REG] = 0xa8,
246 	[OMAP_I2C_SA_REG] = 0xac,
247 	[OMAP_I2C_PSC_REG] = 0xb0,
248 	[OMAP_I2C_SCLL_REG] = 0xb4,
249 	[OMAP_I2C_SCLH_REG] = 0xb8,
250 	[OMAP_I2C_SYSTEST_REG] = 0xbC,
251 	[OMAP_I2C_BUFSTAT_REG] = 0xc0,
252 	[OMAP_I2C_IP_V2_REVNB_LO] = 0x00,
253 	[OMAP_I2C_IP_V2_REVNB_HI] = 0x04,
254 	[OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24,
255 	[OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c,
256 	[OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
257 };
258 
259 static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
260 				      int reg, u16 val)
261 {
262 	__raw_writew(val, i2c_dev->base +
263 			(i2c_dev->regs[reg] << i2c_dev->reg_shift));
264 }
265 
266 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
267 {
268 	return __raw_readw(i2c_dev->base +
269 				(i2c_dev->regs[reg] << i2c_dev->reg_shift));
270 }
271 
272 static int omap_i2c_init(struct omap_i2c_dev *dev)
273 {
274 	u16 psc = 0, scll = 0, sclh = 0, buf = 0;
275 	u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
276 	unsigned long fclk_rate = 12000000;
277 	unsigned long timeout;
278 	unsigned long internal_clk = 0;
279 	struct clk *fclk;
280 
281 	if (dev->rev >= OMAP_I2C_OMAP1_REV_2) {
282 		/* Disable I2C controller before soft reset */
283 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
284 			omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) &
285 				~(OMAP_I2C_CON_EN));
286 
287 		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
288 		/* For some reason we need to set the EN bit before the
289 		 * reset done bit gets set. */
290 		timeout = jiffies + OMAP_I2C_TIMEOUT;
291 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
292 		while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
293 			 SYSS_RESETDONE_MASK)) {
294 			if (time_after(jiffies, timeout)) {
295 				dev_warn(dev->dev, "timeout waiting "
296 						"for controller reset\n");
297 				return -ETIMEDOUT;
298 			}
299 			msleep(1);
300 		}
301 
302 		/* SYSC register is cleared by the reset; rewrite it */
303 		if (dev->rev == OMAP_I2C_REV_ON_2430) {
304 
305 			omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
306 					   SYSC_AUTOIDLE_MASK);
307 
308 		} else if (dev->rev >= OMAP_I2C_REV_ON_3430_3530) {
309 			dev->syscstate = SYSC_AUTOIDLE_MASK;
310 			dev->syscstate |= SYSC_ENAWAKEUP_MASK;
311 			dev->syscstate |= (SYSC_IDLEMODE_SMART <<
312 			      __ffs(SYSC_SIDLEMODE_MASK));
313 			dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK <<
314 			      __ffs(SYSC_CLOCKACTIVITY_MASK));
315 
316 			omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
317 							dev->syscstate);
318 			/*
319 			 * Enabling all wakup sources to stop I2C freezing on
320 			 * WFI instruction.
321 			 * REVISIT: Some wkup sources might not be needed.
322 			 */
323 			dev->westate = OMAP_I2C_WE_ALL;
324 			omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
325 							dev->westate);
326 		}
327 	}
328 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
329 
330 	if (dev->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {
331 		/*
332 		 * The I2C functional clock is the armxor_ck, so there's
333 		 * no need to get "armxor_ck" separately.  Now, if OMAP2420
334 		 * always returns 12MHz for the functional clock, we can
335 		 * do this bit unconditionally.
336 		 */
337 		fclk = clk_get(dev->dev, "fck");
338 		fclk_rate = clk_get_rate(fclk);
339 		clk_put(fclk);
340 
341 		/* TRM for 5912 says the I2C clock must be prescaled to be
342 		 * between 7 - 12 MHz. The XOR input clock is typically
343 		 * 12, 13 or 19.2 MHz. So we should have code that produces:
344 		 *
345 		 * XOR MHz	Divider		Prescaler
346 		 * 12		1		0
347 		 * 13		2		1
348 		 * 19.2		2		1
349 		 */
350 		if (fclk_rate > 12000000)
351 			psc = fclk_rate / 12000000;
352 	}
353 
354 	if (!(dev->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) {
355 
356 		/*
357 		 * HSI2C controller internal clk rate should be 19.2 Mhz for
358 		 * HS and for all modes on 2430. On 34xx we can use lower rate
359 		 * to get longer filter period for better noise suppression.
360 		 * The filter is iclk (fclk for HS) period.
361 		 */
362 		if (dev->speed > 400 ||
363 			       dev->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK)
364 			internal_clk = 19200;
365 		else if (dev->speed > 100)
366 			internal_clk = 9600;
367 		else
368 			internal_clk = 4000;
369 		fclk = clk_get(dev->dev, "fck");
370 		fclk_rate = clk_get_rate(fclk) / 1000;
371 		clk_put(fclk);
372 
373 		/* Compute prescaler divisor */
374 		psc = fclk_rate / internal_clk;
375 		psc = psc - 1;
376 
377 		/* If configured for High Speed */
378 		if (dev->speed > 400) {
379 			unsigned long scl;
380 
381 			/* For first phase of HS mode */
382 			scl = internal_clk / 400;
383 			fsscll = scl - (scl / 3) - 7;
384 			fssclh = (scl / 3) - 5;
385 
386 			/* For second phase of HS mode */
387 			scl = fclk_rate / dev->speed;
388 			hsscll = scl - (scl / 3) - 7;
389 			hssclh = (scl / 3) - 5;
390 		} else if (dev->speed > 100) {
391 			unsigned long scl;
392 
393 			/* Fast mode */
394 			scl = internal_clk / dev->speed;
395 			fsscll = scl - (scl / 3) - 7;
396 			fssclh = (scl / 3) - 5;
397 		} else {
398 			/* Standard mode */
399 			fsscll = internal_clk / (dev->speed * 2) - 7;
400 			fssclh = internal_clk / (dev->speed * 2) - 5;
401 		}
402 		scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
403 		sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
404 	} else {
405 		/* Program desired operating rate */
406 		fclk_rate /= (psc + 1) * 1000;
407 		if (psc > 2)
408 			psc = 2;
409 		scll = fclk_rate / (dev->speed * 2) - 7 + psc;
410 		sclh = fclk_rate / (dev->speed * 2) - 7 + psc;
411 	}
412 
413 	/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
414 	omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
415 
416 	/* SCL low and high time values */
417 	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
418 	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
419 
420 	if (dev->fifo_size) {
421 		/* Note: setup required fifo size - 1. RTRSH and XTRSH */
422 		buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR |
423 			(dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR;
424 		omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
425 	}
426 
427 	/* Take the I2C module out of reset: */
428 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
429 
430 	/* Enable interrupts */
431 	dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
432 			OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
433 			OMAP_I2C_IE_AL)  | ((dev->fifo_size) ?
434 				(OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
435 	omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
436 	if (dev->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
437 		dev->pscstate = psc;
438 		dev->scllstate = scll;
439 		dev->sclhstate = sclh;
440 		dev->bufstate = buf;
441 	}
442 	return 0;
443 }
444 
445 /*
446  * Waiting on Bus Busy
447  */
448 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
449 {
450 	unsigned long timeout;
451 
452 	timeout = jiffies + OMAP_I2C_TIMEOUT;
453 	while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
454 		if (time_after(jiffies, timeout)) {
455 			dev_warn(dev->dev, "timeout waiting for bus ready\n");
456 			return -ETIMEDOUT;
457 		}
458 		msleep(1);
459 	}
460 
461 	return 0;
462 }
463 
464 /*
465  * Low level master read/write transaction.
466  */
467 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
468 			     struct i2c_msg *msg, int stop)
469 {
470 	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
471 	unsigned long timeout;
472 	u16 w;
473 
474 	dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
475 		msg->addr, msg->len, msg->flags, stop);
476 
477 	if (msg->len == 0)
478 		return -EINVAL;
479 
480 	omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
481 
482 	/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
483 	dev->buf = msg->buf;
484 	dev->buf_len = msg->len;
485 
486 	omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
487 
488 	/* Clear the FIFO Buffers */
489 	w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
490 	w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
491 	omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w);
492 
493 	INIT_COMPLETION(dev->cmd_complete);
494 	dev->cmd_err = 0;
495 
496 	w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
497 
498 	/* High speed configuration */
499 	if (dev->speed > 400)
500 		w |= OMAP_I2C_CON_OPMODE_HS;
501 
502 	if (msg->flags & I2C_M_STOP)
503 		stop = 1;
504 	if (msg->flags & I2C_M_TEN)
505 		w |= OMAP_I2C_CON_XA;
506 	if (!(msg->flags & I2C_M_RD))
507 		w |= OMAP_I2C_CON_TRX;
508 
509 	if (!dev->b_hw && stop)
510 		w |= OMAP_I2C_CON_STP;
511 
512 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
513 
514 	/*
515 	 * Don't write stt and stp together on some hardware.
516 	 */
517 	if (dev->b_hw && stop) {
518 		unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
519 		u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
520 		while (con & OMAP_I2C_CON_STT) {
521 			con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
522 
523 			/* Let the user know if i2c is in a bad state */
524 			if (time_after(jiffies, delay)) {
525 				dev_err(dev->dev, "controller timed out "
526 				"waiting for start condition to finish\n");
527 				return -ETIMEDOUT;
528 			}
529 			cpu_relax();
530 		}
531 
532 		w |= OMAP_I2C_CON_STP;
533 		w &= ~OMAP_I2C_CON_STT;
534 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
535 	}
536 
537 	/*
538 	 * REVISIT: We should abort the transfer on signals, but the bus goes
539 	 * into arbitration and we're currently unable to recover from it.
540 	 */
541 	timeout = wait_for_completion_timeout(&dev->cmd_complete,
542 						OMAP_I2C_TIMEOUT);
543 	dev->buf_len = 0;
544 	if (timeout == 0) {
545 		dev_err(dev->dev, "controller timed out\n");
546 		omap_i2c_init(dev);
547 		return -ETIMEDOUT;
548 	}
549 
550 	if (likely(!dev->cmd_err))
551 		return 0;
552 
553 	/* We have an error */
554 	if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
555 			    OMAP_I2C_STAT_XUDF)) {
556 		omap_i2c_init(dev);
557 		return -EIO;
558 	}
559 
560 	if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
561 		if (msg->flags & I2C_M_IGNORE_NAK)
562 			return 0;
563 		if (stop) {
564 			w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
565 			w |= OMAP_I2C_CON_STP;
566 			omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
567 		}
568 		return -EREMOTEIO;
569 	}
570 	return -EIO;
571 }
572 
573 
574 /*
575  * Prepare controller for a transaction and call omap_i2c_xfer_msg
576  * to do the work during IRQ processing.
577  */
578 static int
579 omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
580 {
581 	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
582 	int i;
583 	int r;
584 
585 	r = pm_runtime_get_sync(dev->dev);
586 	if (IS_ERR_VALUE(r))
587 		goto out;
588 
589 	r = omap_i2c_wait_for_bb(dev);
590 	if (r < 0)
591 		goto out;
592 
593 	if (dev->set_mpu_wkup_lat != NULL)
594 		dev->set_mpu_wkup_lat(dev->dev, dev->latency);
595 
596 	for (i = 0; i < num; i++) {
597 		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
598 		if (r != 0)
599 			break;
600 	}
601 
602 	if (dev->set_mpu_wkup_lat != NULL)
603 		dev->set_mpu_wkup_lat(dev->dev, -1);
604 
605 	if (r == 0)
606 		r = num;
607 
608 	omap_i2c_wait_for_bb(dev);
609 out:
610 	pm_runtime_put(dev->dev);
611 	return r;
612 }
613 
614 static u32
615 omap_i2c_func(struct i2c_adapter *adap)
616 {
617 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
618 	       I2C_FUNC_PROTOCOL_MANGLING;
619 }
620 
621 static inline void
622 omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
623 {
624 	dev->cmd_err |= err;
625 	complete(&dev->cmd_complete);
626 }
627 
628 static inline void
629 omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
630 {
631 	omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
632 }
633 
634 static inline void i2c_omap_errata_i207(struct omap_i2c_dev *dev, u16 stat)
635 {
636 	/*
637 	 * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
638 	 * Not applicable for OMAP4.
639 	 * Under certain rare conditions, RDR could be set again
640 	 * when the bus is busy, then ignore the interrupt and
641 	 * clear the interrupt.
642 	 */
643 	if (stat & OMAP_I2C_STAT_RDR) {
644 		/* Step 1: If RDR is set, clear it */
645 		omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
646 
647 		/* Step 2: */
648 		if (!(omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
649 						& OMAP_I2C_STAT_BB)) {
650 
651 			/* Step 3: */
652 			if (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
653 						& OMAP_I2C_STAT_RDR) {
654 				omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
655 				dev_dbg(dev->dev, "RDR when bus is busy.\n");
656 			}
657 
658 		}
659 	}
660 }
661 
662 /* rev1 devices are apparently only on some 15xx */
663 #ifdef CONFIG_ARCH_OMAP15XX
664 
665 static irqreturn_t
666 omap_i2c_omap1_isr(int this_irq, void *dev_id)
667 {
668 	struct omap_i2c_dev *dev = dev_id;
669 	u16 iv, w;
670 
671 	if (pm_runtime_suspended(dev->dev))
672 		return IRQ_NONE;
673 
674 	iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
675 	switch (iv) {
676 	case 0x00:	/* None */
677 		break;
678 	case 0x01:	/* Arbitration lost */
679 		dev_err(dev->dev, "Arbitration lost\n");
680 		omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
681 		break;
682 	case 0x02:	/* No acknowledgement */
683 		omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
684 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
685 		break;
686 	case 0x03:	/* Register access ready */
687 		omap_i2c_complete_cmd(dev, 0);
688 		break;
689 	case 0x04:	/* Receive data ready */
690 		if (dev->buf_len) {
691 			w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
692 			*dev->buf++ = w;
693 			dev->buf_len--;
694 			if (dev->buf_len) {
695 				*dev->buf++ = w >> 8;
696 				dev->buf_len--;
697 			}
698 		} else
699 			dev_err(dev->dev, "RRDY IRQ while no data requested\n");
700 		break;
701 	case 0x05:	/* Transmit data ready */
702 		if (dev->buf_len) {
703 			w = *dev->buf++;
704 			dev->buf_len--;
705 			if (dev->buf_len) {
706 				w |= *dev->buf++ << 8;
707 				dev->buf_len--;
708 			}
709 			omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
710 		} else
711 			dev_err(dev->dev, "XRDY IRQ while no data to send\n");
712 		break;
713 	default:
714 		return IRQ_NONE;
715 	}
716 
717 	return IRQ_HANDLED;
718 }
719 #else
720 #define omap_i2c_omap1_isr		NULL
721 #endif
722 
723 /*
724  * OMAP3430 Errata i462: When an XRDY/XDR is hit, wait for XUDF before writing
725  * data to DATA_REG. Otherwise some data bytes can be lost while transferring
726  * them from the memory to the I2C interface.
727  */
728 static int errata_omap3_i462(struct omap_i2c_dev *dev, u16 *stat, int *err)
729 {
730 	unsigned long timeout = 10000;
731 
732 	while (--timeout && !(*stat & OMAP_I2C_STAT_XUDF)) {
733 		if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
734 			omap_i2c_ack_stat(dev, *stat & (OMAP_I2C_STAT_XRDY |
735 							OMAP_I2C_STAT_XDR));
736 			return -ETIMEDOUT;
737 		}
738 
739 		cpu_relax();
740 		*stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
741 	}
742 
743 	if (!timeout) {
744 		dev_err(dev->dev, "timeout waiting on XUDF bit\n");
745 		return 0;
746 	}
747 
748 	*err |= OMAP_I2C_STAT_XUDF;
749 	return 0;
750 }
751 
752 static irqreturn_t
753 omap_i2c_isr(int this_irq, void *dev_id)
754 {
755 	struct omap_i2c_dev *dev = dev_id;
756 	u16 bits;
757 	u16 stat, w;
758 	int err, count = 0;
759 
760 	if (pm_runtime_suspended(dev->dev))
761 		return IRQ_NONE;
762 
763 	bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
764 	while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
765 		dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
766 		if (count++ == 100) {
767 			dev_warn(dev->dev, "Too much work in one IRQ\n");
768 			break;
769 		}
770 
771 		err = 0;
772 complete:
773 		/*
774 		 * Ack the stat in one go, but [R/X]DR and [R/X]RDY should be
775 		 * acked after the data operation is complete.
776 		 * Ref: TRM SWPU114Q Figure 18-31
777 		 */
778 		omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat &
779 				~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
780 				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
781 
782 		if (stat & OMAP_I2C_STAT_NACK)
783 			err |= OMAP_I2C_STAT_NACK;
784 
785 		if (stat & OMAP_I2C_STAT_AL) {
786 			dev_err(dev->dev, "Arbitration lost\n");
787 			err |= OMAP_I2C_STAT_AL;
788 		}
789 		/*
790 		 * ProDB0017052: Clear ARDY bit twice
791 		 */
792 		if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
793 					OMAP_I2C_STAT_AL)) {
794 			omap_i2c_ack_stat(dev, stat &
795 				(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
796 				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR |
797 				OMAP_I2C_STAT_ARDY));
798 			omap_i2c_complete_cmd(dev, err);
799 			return IRQ_HANDLED;
800 		}
801 		if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
802 			u8 num_bytes = 1;
803 
804 			if (dev->errata & I2C_OMAP_ERRATA_I207)
805 				i2c_omap_errata_i207(dev, stat);
806 
807 			if (dev->fifo_size) {
808 				if (stat & OMAP_I2C_STAT_RRDY)
809 					num_bytes = dev->fifo_size;
810 				else    /* read RXSTAT on RDR interrupt */
811 					num_bytes = (omap_i2c_read_reg(dev,
812 							OMAP_I2C_BUFSTAT_REG)
813 							>> 8) & 0x3F;
814 			}
815 			while (num_bytes) {
816 				num_bytes--;
817 				w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
818 				if (dev->buf_len) {
819 					*dev->buf++ = w;
820 					dev->buf_len--;
821 					/*
822 					 * Data reg in 2430, omap3 and
823 					 * omap4 is 8 bit wide
824 					 */
825 					if (dev->flags &
826 						 OMAP_I2C_FLAG_16BIT_DATA_REG) {
827 						if (dev->buf_len) {
828 							*dev->buf++ = w >> 8;
829 							dev->buf_len--;
830 						}
831 					}
832 				} else {
833 					if (stat & OMAP_I2C_STAT_RRDY)
834 						dev_err(dev->dev,
835 							"RRDY IRQ while no data"
836 								" requested\n");
837 					if (stat & OMAP_I2C_STAT_RDR)
838 						dev_err(dev->dev,
839 							"RDR IRQ while no data"
840 								" requested\n");
841 					break;
842 				}
843 			}
844 			omap_i2c_ack_stat(dev,
845 				stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
846 			continue;
847 		}
848 		if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
849 			u8 num_bytes = 1;
850 			if (dev->fifo_size) {
851 				if (stat & OMAP_I2C_STAT_XRDY)
852 					num_bytes = dev->fifo_size;
853 				else    /* read TXSTAT on XDR interrupt */
854 					num_bytes = omap_i2c_read_reg(dev,
855 							OMAP_I2C_BUFSTAT_REG)
856 							& 0x3F;
857 			}
858 			while (num_bytes) {
859 				num_bytes--;
860 				w = 0;
861 				if (dev->buf_len) {
862 					w = *dev->buf++;
863 					dev->buf_len--;
864 					/*
865 					 * Data reg in 2430, omap3 and
866 					 * omap4 is 8 bit wide
867 					 */
868 					if (dev->flags &
869 						 OMAP_I2C_FLAG_16BIT_DATA_REG) {
870 						if (dev->buf_len) {
871 							w |= *dev->buf++ << 8;
872 							dev->buf_len--;
873 						}
874 					}
875 				} else {
876 					if (stat & OMAP_I2C_STAT_XRDY)
877 						dev_err(dev->dev,
878 							"XRDY IRQ while no "
879 							"data to send\n");
880 					if (stat & OMAP_I2C_STAT_XDR)
881 						dev_err(dev->dev,
882 							"XDR IRQ while no "
883 							"data to send\n");
884 					break;
885 				}
886 
887 				if ((dev->errata & I2C_OMAP_ERRATA_I462) &&
888 				    errata_omap3_i462(dev, &stat, &err))
889 					goto complete;
890 
891 				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
892 			}
893 			omap_i2c_ack_stat(dev,
894 				stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
895 			continue;
896 		}
897 		if (stat & OMAP_I2C_STAT_ROVR) {
898 			dev_err(dev->dev, "Receive overrun\n");
899 			dev->cmd_err |= OMAP_I2C_STAT_ROVR;
900 		}
901 		if (stat & OMAP_I2C_STAT_XUDF) {
902 			dev_err(dev->dev, "Transmit underflow\n");
903 			dev->cmd_err |= OMAP_I2C_STAT_XUDF;
904 		}
905 	}
906 
907 	return count ? IRQ_HANDLED : IRQ_NONE;
908 }
909 
910 static const struct i2c_algorithm omap_i2c_algo = {
911 	.master_xfer	= omap_i2c_xfer,
912 	.functionality	= omap_i2c_func,
913 };
914 
915 #ifdef CONFIG_OF
916 static struct omap_i2c_bus_platform_data omap3_pdata = {
917 	.rev = OMAP_I2C_IP_VERSION_1,
918 	.flags = OMAP_I2C_FLAG_APPLY_ERRATA_I207 |
919 		 OMAP_I2C_FLAG_RESET_REGS_POSTIDLE |
920 		 OMAP_I2C_FLAG_BUS_SHIFT_2,
921 };
922 
923 static struct omap_i2c_bus_platform_data omap4_pdata = {
924 	.rev = OMAP_I2C_IP_VERSION_2,
925 };
926 
927 static const struct of_device_id omap_i2c_of_match[] = {
928 	{
929 		.compatible = "ti,omap4-i2c",
930 		.data = &omap4_pdata,
931 	},
932 	{
933 		.compatible = "ti,omap3-i2c",
934 		.data = &omap3_pdata,
935 	},
936 	{ },
937 };
938 MODULE_DEVICE_TABLE(of, omap_i2c_of_match);
939 #endif
940 
941 static int __devinit
942 omap_i2c_probe(struct platform_device *pdev)
943 {
944 	struct omap_i2c_dev	*dev;
945 	struct i2c_adapter	*adap;
946 	struct resource		*mem, *irq, *ioarea;
947 	struct omap_i2c_bus_platform_data *pdata = pdev->dev.platform_data;
948 	struct device_node	*node = pdev->dev.of_node;
949 	const struct of_device_id *match;
950 	irq_handler_t isr;
951 	int r;
952 
953 	/* NOTE: driver uses the static register mapping */
954 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
955 	if (!mem) {
956 		dev_err(&pdev->dev, "no mem resource?\n");
957 		return -ENODEV;
958 	}
959 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
960 	if (!irq) {
961 		dev_err(&pdev->dev, "no irq resource?\n");
962 		return -ENODEV;
963 	}
964 
965 	ioarea = request_mem_region(mem->start, resource_size(mem),
966 			pdev->name);
967 	if (!ioarea) {
968 		dev_err(&pdev->dev, "I2C region already claimed\n");
969 		return -EBUSY;
970 	}
971 
972 	dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
973 	if (!dev) {
974 		r = -ENOMEM;
975 		goto err_release_region;
976 	}
977 
978 	match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev);
979 	if (match) {
980 		u32 freq = 100000; /* default to 100000 Hz */
981 
982 		pdata = match->data;
983 		dev->dtrev = pdata->rev;
984 		dev->flags = pdata->flags;
985 
986 		of_property_read_u32(node, "clock-frequency", &freq);
987 		/* convert DT freq value in Hz into kHz for speed */
988 		dev->speed = freq / 1000;
989 	} else if (pdata != NULL) {
990 		dev->speed = pdata->clkrate;
991 		dev->flags = pdata->flags;
992 		dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
993 		dev->dtrev = pdata->rev;
994 	}
995 
996 	dev->dev = &pdev->dev;
997 	dev->irq = irq->start;
998 	dev->base = ioremap(mem->start, resource_size(mem));
999 	if (!dev->base) {
1000 		r = -ENOMEM;
1001 		goto err_free_mem;
1002 	}
1003 
1004 	platform_set_drvdata(pdev, dev);
1005 	init_completion(&dev->cmd_complete);
1006 
1007 	dev->reg_shift = (dev->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
1008 
1009 	if (dev->dtrev == OMAP_I2C_IP_VERSION_2)
1010 		dev->regs = (u8 *)reg_map_ip_v2;
1011 	else
1012 		dev->regs = (u8 *)reg_map_ip_v1;
1013 
1014 	pm_runtime_enable(dev->dev);
1015 	r = pm_runtime_get_sync(dev->dev);
1016 	if (IS_ERR_VALUE(r))
1017 		goto err_free_mem;
1018 
1019 	dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
1020 
1021 	dev->errata = 0;
1022 
1023 	if (dev->flags & OMAP_I2C_FLAG_APPLY_ERRATA_I207)
1024 		dev->errata |= I2C_OMAP_ERRATA_I207;
1025 
1026 	if (dev->rev <= OMAP_I2C_REV_ON_3430_3530)
1027 		dev->errata |= I2C_OMAP_ERRATA_I462;
1028 
1029 	if (!(dev->flags & OMAP_I2C_FLAG_NO_FIFO)) {
1030 		u16 s;
1031 
1032 		/* Set up the fifo size - Get total size */
1033 		s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
1034 		dev->fifo_size = 0x8 << s;
1035 
1036 		/*
1037 		 * Set up notification threshold as half the total available
1038 		 * size. This is to ensure that we can handle the status on int
1039 		 * call back latencies.
1040 		 */
1041 
1042 		dev->fifo_size = (dev->fifo_size / 2);
1043 
1044 		if (dev->rev >= OMAP_I2C_REV_ON_3630_4430)
1045 			dev->b_hw = 0; /* Disable hardware fixes */
1046 		else
1047 			dev->b_hw = 1; /* Enable hardware fixes */
1048 
1049 		/* calculate wakeup latency constraint for MPU */
1050 		if (dev->set_mpu_wkup_lat != NULL)
1051 			dev->latency = (1000000 * dev->fifo_size) /
1052 				       (1000 * dev->speed / 8);
1053 	}
1054 
1055 	/* reset ASAP, clearing any IRQs */
1056 	omap_i2c_init(dev);
1057 
1058 	isr = (dev->rev < OMAP_I2C_OMAP1_REV_2) ? omap_i2c_omap1_isr :
1059 								   omap_i2c_isr;
1060 	r = request_irq(dev->irq, isr, IRQF_NO_SUSPEND, pdev->name, dev);
1061 
1062 	if (r) {
1063 		dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
1064 		goto err_unuse_clocks;
1065 	}
1066 
1067 	dev_info(dev->dev, "bus %d rev%d.%d.%d at %d kHz\n", pdev->id,
1068 		 dev->dtrev, dev->rev >> 4, dev->rev & 0xf, dev->speed);
1069 
1070 	adap = &dev->adapter;
1071 	i2c_set_adapdata(adap, dev);
1072 	adap->owner = THIS_MODULE;
1073 	adap->class = I2C_CLASS_HWMON;
1074 	strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
1075 	adap->algo = &omap_i2c_algo;
1076 	adap->dev.parent = &pdev->dev;
1077 	adap->dev.of_node = pdev->dev.of_node;
1078 
1079 	/* i2c device drivers may be active on return from add_adapter() */
1080 	adap->nr = pdev->id;
1081 	r = i2c_add_numbered_adapter(adap);
1082 	if (r) {
1083 		dev_err(dev->dev, "failure adding adapter\n");
1084 		goto err_free_irq;
1085 	}
1086 
1087 	of_i2c_register_devices(adap);
1088 
1089 	pm_runtime_put(dev->dev);
1090 
1091 	return 0;
1092 
1093 err_free_irq:
1094 	free_irq(dev->irq, dev);
1095 err_unuse_clocks:
1096 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1097 	pm_runtime_put(dev->dev);
1098 	iounmap(dev->base);
1099 	pm_runtime_disable(&pdev->dev);
1100 err_free_mem:
1101 	platform_set_drvdata(pdev, NULL);
1102 	kfree(dev);
1103 err_release_region:
1104 	release_mem_region(mem->start, resource_size(mem));
1105 
1106 	return r;
1107 }
1108 
1109 static int __devexit omap_i2c_remove(struct platform_device *pdev)
1110 {
1111 	struct omap_i2c_dev	*dev = platform_get_drvdata(pdev);
1112 	struct resource		*mem;
1113 	int ret;
1114 
1115 	platform_set_drvdata(pdev, NULL);
1116 
1117 	free_irq(dev->irq, dev);
1118 	i2c_del_adapter(&dev->adapter);
1119 	ret = pm_runtime_get_sync(&pdev->dev);
1120 	if (IS_ERR_VALUE(ret))
1121 		return ret;
1122 
1123 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1124 	pm_runtime_put(&pdev->dev);
1125 	pm_runtime_disable(&pdev->dev);
1126 	iounmap(dev->base);
1127 	kfree(dev);
1128 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1129 	release_mem_region(mem->start, resource_size(mem));
1130 	return 0;
1131 }
1132 
1133 #ifdef CONFIG_PM
1134 #ifdef CONFIG_PM_RUNTIME
1135 static int omap_i2c_runtime_suspend(struct device *dev)
1136 {
1137 	struct platform_device *pdev = to_platform_device(dev);
1138 	struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
1139 	u16 iv;
1140 
1141 	_dev->iestate = omap_i2c_read_reg(_dev, OMAP_I2C_IE_REG);
1142 
1143 	omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, 0);
1144 
1145 	if (_dev->rev < OMAP_I2C_OMAP1_REV_2) {
1146 		iv = omap_i2c_read_reg(_dev, OMAP_I2C_IV_REG); /* Read clears */
1147 	} else {
1148 		omap_i2c_write_reg(_dev, OMAP_I2C_STAT_REG, _dev->iestate);
1149 
1150 		/* Flush posted write */
1151 		omap_i2c_read_reg(_dev, OMAP_I2C_STAT_REG);
1152 	}
1153 
1154 	return 0;
1155 }
1156 
1157 static int omap_i2c_runtime_resume(struct device *dev)
1158 {
1159 	struct platform_device *pdev = to_platform_device(dev);
1160 	struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
1161 
1162 	if (_dev->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
1163 		omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, 0);
1164 		omap_i2c_write_reg(_dev, OMAP_I2C_PSC_REG, _dev->pscstate);
1165 		omap_i2c_write_reg(_dev, OMAP_I2C_SCLL_REG, _dev->scllstate);
1166 		omap_i2c_write_reg(_dev, OMAP_I2C_SCLH_REG, _dev->sclhstate);
1167 		omap_i2c_write_reg(_dev, OMAP_I2C_BUF_REG, _dev->bufstate);
1168 		omap_i2c_write_reg(_dev, OMAP_I2C_SYSC_REG, _dev->syscstate);
1169 		omap_i2c_write_reg(_dev, OMAP_I2C_WE_REG, _dev->westate);
1170 		omap_i2c_write_reg(_dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
1171 	}
1172 
1173 	/*
1174 	 * Don't write to this register if the IE state is 0 as it can
1175 	 * cause deadlock.
1176 	 */
1177 	if (_dev->iestate)
1178 		omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, _dev->iestate);
1179 
1180 	return 0;
1181 }
1182 #endif /* CONFIG_PM_RUNTIME */
1183 
1184 static struct dev_pm_ops omap_i2c_pm_ops = {
1185 	SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
1186 			   omap_i2c_runtime_resume, NULL)
1187 };
1188 #define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
1189 #else
1190 #define OMAP_I2C_PM_OPS NULL
1191 #endif /* CONFIG_PM */
1192 
1193 static struct platform_driver omap_i2c_driver = {
1194 	.probe		= omap_i2c_probe,
1195 	.remove		= __devexit_p(omap_i2c_remove),
1196 	.driver		= {
1197 		.name	= "omap_i2c",
1198 		.owner	= THIS_MODULE,
1199 		.pm	= OMAP_I2C_PM_OPS,
1200 		.of_match_table = of_match_ptr(omap_i2c_of_match),
1201 	},
1202 };
1203 
1204 /* I2C may be needed to bring up other drivers */
1205 static int __init
1206 omap_i2c_init_driver(void)
1207 {
1208 	return platform_driver_register(&omap_i2c_driver);
1209 }
1210 subsys_initcall(omap_i2c_init_driver);
1211 
1212 static void __exit omap_i2c_exit_driver(void)
1213 {
1214 	platform_driver_unregister(&omap_i2c_driver);
1215 }
1216 module_exit(omap_i2c_exit_driver);
1217 
1218 MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
1219 MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
1220 MODULE_LICENSE("GPL");
1221 MODULE_ALIAS("platform:omap_i2c");
1222