xref: /openbmc/linux/drivers/i2c/busses/i2c-omap.c (revision 565d76cb)
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/slab.h>
41 #include <linux/i2c-omap.h>
42 #include <linux/pm_runtime.h>
43 
44 /* I2C controller revisions */
45 #define OMAP_I2C_REV_2			0x20
46 
47 /* I2C controller revisions present on specific hardware */
48 #define OMAP_I2C_REV_ON_2430		0x36
49 #define OMAP_I2C_REV_ON_3430		0x3C
50 #define OMAP_I2C_REV_ON_4430		0x40
51 
52 /* timeout waiting for the controller to respond */
53 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
54 
55 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
56 enum {
57 	OMAP_I2C_REV_REG = 0,
58 	OMAP_I2C_IE_REG,
59 	OMAP_I2C_STAT_REG,
60 	OMAP_I2C_IV_REG,
61 	OMAP_I2C_WE_REG,
62 	OMAP_I2C_SYSS_REG,
63 	OMAP_I2C_BUF_REG,
64 	OMAP_I2C_CNT_REG,
65 	OMAP_I2C_DATA_REG,
66 	OMAP_I2C_SYSC_REG,
67 	OMAP_I2C_CON_REG,
68 	OMAP_I2C_OA_REG,
69 	OMAP_I2C_SA_REG,
70 	OMAP_I2C_PSC_REG,
71 	OMAP_I2C_SCLL_REG,
72 	OMAP_I2C_SCLH_REG,
73 	OMAP_I2C_SYSTEST_REG,
74 	OMAP_I2C_BUFSTAT_REG,
75 	OMAP_I2C_REVNB_LO,
76 	OMAP_I2C_REVNB_HI,
77 	OMAP_I2C_IRQSTATUS_RAW,
78 	OMAP_I2C_IRQENABLE_SET,
79 	OMAP_I2C_IRQENABLE_CLR,
80 };
81 
82 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
83 #define OMAP_I2C_IE_XDR		(1 << 14)	/* TX Buffer drain int enable */
84 #define OMAP_I2C_IE_RDR		(1 << 13)	/* RX Buffer drain int enable */
85 #define OMAP_I2C_IE_XRDY	(1 << 4)	/* TX data ready int enable */
86 #define OMAP_I2C_IE_RRDY	(1 << 3)	/* RX data ready int enable */
87 #define OMAP_I2C_IE_ARDY	(1 << 2)	/* Access ready int enable */
88 #define OMAP_I2C_IE_NACK	(1 << 1)	/* No ack interrupt enable */
89 #define OMAP_I2C_IE_AL		(1 << 0)	/* Arbitration lost int ena */
90 
91 /* I2C Status Register (OMAP_I2C_STAT): */
92 #define OMAP_I2C_STAT_XDR	(1 << 14)	/* TX Buffer draining */
93 #define OMAP_I2C_STAT_RDR	(1 << 13)	/* RX Buffer draining */
94 #define OMAP_I2C_STAT_BB	(1 << 12)	/* Bus busy */
95 #define OMAP_I2C_STAT_ROVR	(1 << 11)	/* Receive overrun */
96 #define OMAP_I2C_STAT_XUDF	(1 << 10)	/* Transmit underflow */
97 #define OMAP_I2C_STAT_AAS	(1 << 9)	/* Address as slave */
98 #define OMAP_I2C_STAT_AD0	(1 << 8)	/* Address zero */
99 #define OMAP_I2C_STAT_XRDY	(1 << 4)	/* Transmit data ready */
100 #define OMAP_I2C_STAT_RRDY	(1 << 3)	/* Receive data ready */
101 #define OMAP_I2C_STAT_ARDY	(1 << 2)	/* Register access ready */
102 #define OMAP_I2C_STAT_NACK	(1 << 1)	/* No ack interrupt enable */
103 #define OMAP_I2C_STAT_AL	(1 << 0)	/* Arbitration lost int ena */
104 
105 /* I2C WE wakeup enable register */
106 #define OMAP_I2C_WE_XDR_WE	(1 << 14)	/* TX drain wakup */
107 #define OMAP_I2C_WE_RDR_WE	(1 << 13)	/* RX drain wakeup */
108 #define OMAP_I2C_WE_AAS_WE	(1 << 9)	/* Address as slave wakeup*/
109 #define OMAP_I2C_WE_BF_WE	(1 << 8)	/* Bus free wakeup */
110 #define OMAP_I2C_WE_STC_WE	(1 << 6)	/* Start condition wakeup */
111 #define OMAP_I2C_WE_GC_WE	(1 << 5)	/* General call wakeup */
112 #define OMAP_I2C_WE_DRDY_WE	(1 << 3)	/* TX/RX data ready wakeup */
113 #define OMAP_I2C_WE_ARDY_WE	(1 << 2)	/* Reg access ready wakeup */
114 #define OMAP_I2C_WE_NACK_WE	(1 << 1)	/* No acknowledgment wakeup */
115 #define OMAP_I2C_WE_AL_WE	(1 << 0)	/* Arbitration lost wakeup */
116 
117 #define OMAP_I2C_WE_ALL		(OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
118 				OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
119 				OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
120 				OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
121 				OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
122 
123 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
124 #define OMAP_I2C_BUF_RDMA_EN	(1 << 15)	/* RX DMA channel enable */
125 #define OMAP_I2C_BUF_RXFIF_CLR	(1 << 14)	/* RX FIFO Clear */
126 #define OMAP_I2C_BUF_XDMA_EN	(1 << 7)	/* TX DMA channel enable */
127 #define OMAP_I2C_BUF_TXFIF_CLR	(1 << 6)	/* TX FIFO Clear */
128 
129 /* I2C Configuration Register (OMAP_I2C_CON): */
130 #define OMAP_I2C_CON_EN		(1 << 15)	/* I2C module enable */
131 #define OMAP_I2C_CON_BE		(1 << 14)	/* Big endian mode */
132 #define OMAP_I2C_CON_OPMODE_HS	(1 << 12)	/* High Speed support */
133 #define OMAP_I2C_CON_STB	(1 << 11)	/* Start byte mode (master) */
134 #define OMAP_I2C_CON_MST	(1 << 10)	/* Master/slave mode */
135 #define OMAP_I2C_CON_TRX	(1 << 9)	/* TX/RX mode (master only) */
136 #define OMAP_I2C_CON_XA		(1 << 8)	/* Expand address */
137 #define OMAP_I2C_CON_RM		(1 << 2)	/* Repeat mode (master only) */
138 #define OMAP_I2C_CON_STP	(1 << 1)	/* Stop cond (master only) */
139 #define OMAP_I2C_CON_STT	(1 << 0)	/* Start condition (master) */
140 
141 /* I2C SCL time value when Master */
142 #define OMAP_I2C_SCLL_HSSCLL	8
143 #define OMAP_I2C_SCLH_HSSCLH	8
144 
145 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
146 #ifdef DEBUG
147 #define OMAP_I2C_SYSTEST_ST_EN		(1 << 15)	/* System test enable */
148 #define OMAP_I2C_SYSTEST_FREE		(1 << 14)	/* Free running mode */
149 #define OMAP_I2C_SYSTEST_TMODE_MASK	(3 << 12)	/* Test mode select */
150 #define OMAP_I2C_SYSTEST_TMODE_SHIFT	(12)		/* Test mode select */
151 #define OMAP_I2C_SYSTEST_SCL_I		(1 << 3)	/* SCL line sense in */
152 #define OMAP_I2C_SYSTEST_SCL_O		(1 << 2)	/* SCL line drive out */
153 #define OMAP_I2C_SYSTEST_SDA_I		(1 << 1)	/* SDA line sense in */
154 #define OMAP_I2C_SYSTEST_SDA_O		(1 << 0)	/* SDA line drive out */
155 #endif
156 
157 /* OCP_SYSSTATUS bit definitions */
158 #define SYSS_RESETDONE_MASK		(1 << 0)
159 
160 /* OCP_SYSCONFIG bit definitions */
161 #define SYSC_CLOCKACTIVITY_MASK		(0x3 << 8)
162 #define SYSC_SIDLEMODE_MASK		(0x3 << 3)
163 #define SYSC_ENAWAKEUP_MASK		(1 << 2)
164 #define SYSC_SOFTRESET_MASK		(1 << 1)
165 #define SYSC_AUTOIDLE_MASK		(1 << 0)
166 
167 #define SYSC_IDLEMODE_SMART		0x2
168 #define SYSC_CLOCKACTIVITY_FCLK		0x2
169 
170 /* Errata definitions */
171 #define I2C_OMAP_ERRATA_I207		(1 << 0)
172 #define I2C_OMAP3_1P153			(1 << 1)
173 
174 struct omap_i2c_dev {
175 	struct device		*dev;
176 	void __iomem		*base;		/* virtual */
177 	int			irq;
178 	int			reg_shift;      /* bit shift for I2C register addresses */
179 	struct completion	cmd_complete;
180 	struct resource		*ioarea;
181 	u32			latency;	/* maximum mpu wkup latency */
182 	void			(*set_mpu_wkup_lat)(struct device *dev,
183 						    long latency);
184 	u32			speed;		/* Speed of bus in Khz */
185 	u16			cmd_err;
186 	u8			*buf;
187 	u8			*regs;
188 	size_t			buf_len;
189 	struct i2c_adapter	adapter;
190 	u8			fifo_size;	/* use as flag and value
191 						 * fifo_size==0 implies no fifo
192 						 * if set, should be trsh+1
193 						 */
194 	u8			rev;
195 	unsigned		b_hw:1;		/* bad h/w fixes */
196 	unsigned		idle:1;
197 	u16			iestate;	/* Saved interrupt register */
198 	u16			pscstate;
199 	u16			scllstate;
200 	u16			sclhstate;
201 	u16			bufstate;
202 	u16			syscstate;
203 	u16			westate;
204 	u16			errata;
205 };
206 
207 const static u8 reg_map[] = {
208 	[OMAP_I2C_REV_REG] = 0x00,
209 	[OMAP_I2C_IE_REG] = 0x01,
210 	[OMAP_I2C_STAT_REG] = 0x02,
211 	[OMAP_I2C_IV_REG] = 0x03,
212 	[OMAP_I2C_WE_REG] = 0x03,
213 	[OMAP_I2C_SYSS_REG] = 0x04,
214 	[OMAP_I2C_BUF_REG] = 0x05,
215 	[OMAP_I2C_CNT_REG] = 0x06,
216 	[OMAP_I2C_DATA_REG] = 0x07,
217 	[OMAP_I2C_SYSC_REG] = 0x08,
218 	[OMAP_I2C_CON_REG] = 0x09,
219 	[OMAP_I2C_OA_REG] = 0x0a,
220 	[OMAP_I2C_SA_REG] = 0x0b,
221 	[OMAP_I2C_PSC_REG] = 0x0c,
222 	[OMAP_I2C_SCLL_REG] = 0x0d,
223 	[OMAP_I2C_SCLH_REG] = 0x0e,
224 	[OMAP_I2C_SYSTEST_REG] = 0x0f,
225 	[OMAP_I2C_BUFSTAT_REG] = 0x10,
226 };
227 
228 const static u8 omap4_reg_map[] = {
229 	[OMAP_I2C_REV_REG] = 0x04,
230 	[OMAP_I2C_IE_REG] = 0x2c,
231 	[OMAP_I2C_STAT_REG] = 0x28,
232 	[OMAP_I2C_IV_REG] = 0x34,
233 	[OMAP_I2C_WE_REG] = 0x34,
234 	[OMAP_I2C_SYSS_REG] = 0x90,
235 	[OMAP_I2C_BUF_REG] = 0x94,
236 	[OMAP_I2C_CNT_REG] = 0x98,
237 	[OMAP_I2C_DATA_REG] = 0x9c,
238 	[OMAP_I2C_SYSC_REG] = 0x20,
239 	[OMAP_I2C_CON_REG] = 0xa4,
240 	[OMAP_I2C_OA_REG] = 0xa8,
241 	[OMAP_I2C_SA_REG] = 0xac,
242 	[OMAP_I2C_PSC_REG] = 0xb0,
243 	[OMAP_I2C_SCLL_REG] = 0xb4,
244 	[OMAP_I2C_SCLH_REG] = 0xb8,
245 	[OMAP_I2C_SYSTEST_REG] = 0xbC,
246 	[OMAP_I2C_BUFSTAT_REG] = 0xc0,
247 	[OMAP_I2C_REVNB_LO] = 0x00,
248 	[OMAP_I2C_REVNB_HI] = 0x04,
249 	[OMAP_I2C_IRQSTATUS_RAW] = 0x24,
250 	[OMAP_I2C_IRQENABLE_SET] = 0x2c,
251 	[OMAP_I2C_IRQENABLE_CLR] = 0x30,
252 };
253 
254 static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
255 				      int reg, u16 val)
256 {
257 	__raw_writew(val, i2c_dev->base +
258 			(i2c_dev->regs[reg] << i2c_dev->reg_shift));
259 }
260 
261 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
262 {
263 	return __raw_readw(i2c_dev->base +
264 				(i2c_dev->regs[reg] << i2c_dev->reg_shift));
265 }
266 
267 static void omap_i2c_unidle(struct omap_i2c_dev *dev)
268 {
269 	struct platform_device *pdev;
270 	struct omap_i2c_bus_platform_data *pdata;
271 
272 	WARN_ON(!dev->idle);
273 
274 	pdev = to_platform_device(dev->dev);
275 	pdata = pdev->dev.platform_data;
276 
277 	pm_runtime_get_sync(&pdev->dev);
278 
279 	if (cpu_is_omap34xx()) {
280 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
281 		omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
282 		omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
283 		omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
284 		omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
285 		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, dev->syscstate);
286 		omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
287 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
288 	}
289 	dev->idle = 0;
290 
291 	/*
292 	 * Don't write to this register if the IE state is 0 as it can
293 	 * cause deadlock.
294 	 */
295 	if (dev->iestate)
296 		omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
297 }
298 
299 static void omap_i2c_idle(struct omap_i2c_dev *dev)
300 {
301 	struct platform_device *pdev;
302 	struct omap_i2c_bus_platform_data *pdata;
303 	u16 iv;
304 
305 	WARN_ON(dev->idle);
306 
307 	pdev = to_platform_device(dev->dev);
308 	pdata = pdev->dev.platform_data;
309 
310 	dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
311 	if (dev->rev >= OMAP_I2C_REV_ON_4430)
312 		omap_i2c_write_reg(dev, OMAP_I2C_IRQENABLE_CLR, 1);
313 	else
314 		omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
315 
316 	if (dev->rev < OMAP_I2C_REV_2) {
317 		iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); /* Read clears */
318 	} else {
319 		omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);
320 
321 		/* Flush posted write before the dev->idle store occurs */
322 		omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
323 	}
324 	dev->idle = 1;
325 
326 	pm_runtime_put_sync(&pdev->dev);
327 }
328 
329 static int omap_i2c_init(struct omap_i2c_dev *dev)
330 {
331 	u16 psc = 0, scll = 0, sclh = 0, buf = 0;
332 	u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
333 	unsigned long fclk_rate = 12000000;
334 	unsigned long timeout;
335 	unsigned long internal_clk = 0;
336 	struct clk *fclk;
337 
338 	if (dev->rev >= OMAP_I2C_REV_2) {
339 		/* Disable I2C controller before soft reset */
340 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
341 			omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) &
342 				~(OMAP_I2C_CON_EN));
343 
344 		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
345 		/* For some reason we need to set the EN bit before the
346 		 * reset done bit gets set. */
347 		timeout = jiffies + OMAP_I2C_TIMEOUT;
348 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
349 		while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
350 			 SYSS_RESETDONE_MASK)) {
351 			if (time_after(jiffies, timeout)) {
352 				dev_warn(dev->dev, "timeout waiting "
353 						"for controller reset\n");
354 				return -ETIMEDOUT;
355 			}
356 			msleep(1);
357 		}
358 
359 		/* SYSC register is cleared by the reset; rewrite it */
360 		if (dev->rev == OMAP_I2C_REV_ON_2430) {
361 
362 			omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
363 					   SYSC_AUTOIDLE_MASK);
364 
365 		} else if (dev->rev >= OMAP_I2C_REV_ON_3430) {
366 			dev->syscstate = SYSC_AUTOIDLE_MASK;
367 			dev->syscstate |= SYSC_ENAWAKEUP_MASK;
368 			dev->syscstate |= (SYSC_IDLEMODE_SMART <<
369 			      __ffs(SYSC_SIDLEMODE_MASK));
370 			dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK <<
371 			      __ffs(SYSC_CLOCKACTIVITY_MASK));
372 
373 			omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
374 							dev->syscstate);
375 			/*
376 			 * Enabling all wakup sources to stop I2C freezing on
377 			 * WFI instruction.
378 			 * REVISIT: Some wkup sources might not be needed.
379 			 */
380 			dev->westate = OMAP_I2C_WE_ALL;
381 			omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
382 		}
383 	}
384 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
385 
386 	if (cpu_class_is_omap1()) {
387 		/*
388 		 * The I2C functional clock is the armxor_ck, so there's
389 		 * no need to get "armxor_ck" separately.  Now, if OMAP2420
390 		 * always returns 12MHz for the functional clock, we can
391 		 * do this bit unconditionally.
392 		 */
393 		fclk = clk_get(dev->dev, "fck");
394 		fclk_rate = clk_get_rate(fclk);
395 		clk_put(fclk);
396 
397 		/* TRM for 5912 says the I2C clock must be prescaled to be
398 		 * between 7 - 12 MHz. The XOR input clock is typically
399 		 * 12, 13 or 19.2 MHz. So we should have code that produces:
400 		 *
401 		 * XOR MHz	Divider		Prescaler
402 		 * 12		1		0
403 		 * 13		2		1
404 		 * 19.2		2		1
405 		 */
406 		if (fclk_rate > 12000000)
407 			psc = fclk_rate / 12000000;
408 	}
409 
410 	if (!(cpu_class_is_omap1() || cpu_is_omap2420())) {
411 
412 		/*
413 		 * HSI2C controller internal clk rate should be 19.2 Mhz for
414 		 * HS and for all modes on 2430. On 34xx we can use lower rate
415 		 * to get longer filter period for better noise suppression.
416 		 * The filter is iclk (fclk for HS) period.
417 		 */
418 		if (dev->speed > 400 || cpu_is_omap2430())
419 			internal_clk = 19200;
420 		else if (dev->speed > 100)
421 			internal_clk = 9600;
422 		else
423 			internal_clk = 4000;
424 		fclk = clk_get(dev->dev, "fck");
425 		fclk_rate = clk_get_rate(fclk) / 1000;
426 		clk_put(fclk);
427 
428 		/* Compute prescaler divisor */
429 		psc = fclk_rate / internal_clk;
430 		psc = psc - 1;
431 
432 		/* If configured for High Speed */
433 		if (dev->speed > 400) {
434 			unsigned long scl;
435 
436 			/* For first phase of HS mode */
437 			scl = internal_clk / 400;
438 			fsscll = scl - (scl / 3) - 7;
439 			fssclh = (scl / 3) - 5;
440 
441 			/* For second phase of HS mode */
442 			scl = fclk_rate / dev->speed;
443 			hsscll = scl - (scl / 3) - 7;
444 			hssclh = (scl / 3) - 5;
445 		} else if (dev->speed > 100) {
446 			unsigned long scl;
447 
448 			/* Fast mode */
449 			scl = internal_clk / dev->speed;
450 			fsscll = scl - (scl / 3) - 7;
451 			fssclh = (scl / 3) - 5;
452 		} else {
453 			/* Standard mode */
454 			fsscll = internal_clk / (dev->speed * 2) - 7;
455 			fssclh = internal_clk / (dev->speed * 2) - 5;
456 		}
457 		scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
458 		sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
459 	} else {
460 		/* Program desired operating rate */
461 		fclk_rate /= (psc + 1) * 1000;
462 		if (psc > 2)
463 			psc = 2;
464 		scll = fclk_rate / (dev->speed * 2) - 7 + psc;
465 		sclh = fclk_rate / (dev->speed * 2) - 7 + psc;
466 	}
467 
468 	/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
469 	omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
470 
471 	/* SCL low and high time values */
472 	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
473 	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
474 
475 	if (dev->fifo_size) {
476 		/* Note: setup required fifo size - 1. RTRSH and XTRSH */
477 		buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR |
478 			(dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR;
479 		omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
480 	}
481 
482 	/* Take the I2C module out of reset: */
483 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
484 
485 	dev->errata = 0;
486 
487 	if (cpu_is_omap2430() || cpu_is_omap34xx())
488 		dev->errata |= I2C_OMAP_ERRATA_I207;
489 
490 	/* Enable interrupts */
491 	dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
492 			OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
493 			OMAP_I2C_IE_AL)  | ((dev->fifo_size) ?
494 				(OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
495 	omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
496 	if (cpu_is_omap34xx()) {
497 		dev->pscstate = psc;
498 		dev->scllstate = scll;
499 		dev->sclhstate = sclh;
500 		dev->bufstate = buf;
501 	}
502 	return 0;
503 }
504 
505 /*
506  * Waiting on Bus Busy
507  */
508 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
509 {
510 	unsigned long timeout;
511 
512 	timeout = jiffies + OMAP_I2C_TIMEOUT;
513 	while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
514 		if (time_after(jiffies, timeout)) {
515 			dev_warn(dev->dev, "timeout waiting for bus ready\n");
516 			return -ETIMEDOUT;
517 		}
518 		msleep(1);
519 	}
520 
521 	return 0;
522 }
523 
524 /*
525  * Low level master read/write transaction.
526  */
527 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
528 			     struct i2c_msg *msg, int stop)
529 {
530 	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
531 	int r;
532 	u16 w;
533 
534 	dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
535 		msg->addr, msg->len, msg->flags, stop);
536 
537 	if (msg->len == 0)
538 		return -EINVAL;
539 
540 	omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
541 
542 	/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
543 	dev->buf = msg->buf;
544 	dev->buf_len = msg->len;
545 
546 	omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
547 
548 	/* Clear the FIFO Buffers */
549 	w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
550 	w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
551 	omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w);
552 
553 	init_completion(&dev->cmd_complete);
554 	dev->cmd_err = 0;
555 
556 	w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
557 
558 	/* High speed configuration */
559 	if (dev->speed > 400)
560 		w |= OMAP_I2C_CON_OPMODE_HS;
561 
562 	if (msg->flags & I2C_M_TEN)
563 		w |= OMAP_I2C_CON_XA;
564 	if (!(msg->flags & I2C_M_RD))
565 		w |= OMAP_I2C_CON_TRX;
566 
567 	if (!dev->b_hw && stop)
568 		w |= OMAP_I2C_CON_STP;
569 
570 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
571 
572 	/*
573 	 * Don't write stt and stp together on some hardware.
574 	 */
575 	if (dev->b_hw && stop) {
576 		unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
577 		u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
578 		while (con & OMAP_I2C_CON_STT) {
579 			con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
580 
581 			/* Let the user know if i2c is in a bad state */
582 			if (time_after(jiffies, delay)) {
583 				dev_err(dev->dev, "controller timed out "
584 				"waiting for start condition to finish\n");
585 				return -ETIMEDOUT;
586 			}
587 			cpu_relax();
588 		}
589 
590 		w |= OMAP_I2C_CON_STP;
591 		w &= ~OMAP_I2C_CON_STT;
592 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
593 	}
594 
595 	/*
596 	 * REVISIT: We should abort the transfer on signals, but the bus goes
597 	 * into arbitration and we're currently unable to recover from it.
598 	 */
599 	r = wait_for_completion_timeout(&dev->cmd_complete,
600 					OMAP_I2C_TIMEOUT);
601 	dev->buf_len = 0;
602 	if (r < 0)
603 		return r;
604 	if (r == 0) {
605 		dev_err(dev->dev, "controller timed out\n");
606 		omap_i2c_init(dev);
607 		return -ETIMEDOUT;
608 	}
609 
610 	if (likely(!dev->cmd_err))
611 		return 0;
612 
613 	/* We have an error */
614 	if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
615 			    OMAP_I2C_STAT_XUDF)) {
616 		omap_i2c_init(dev);
617 		return -EIO;
618 	}
619 
620 	if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
621 		if (msg->flags & I2C_M_IGNORE_NAK)
622 			return 0;
623 		if (stop) {
624 			w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
625 			w |= OMAP_I2C_CON_STP;
626 			omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
627 		}
628 		return -EREMOTEIO;
629 	}
630 	return -EIO;
631 }
632 
633 
634 /*
635  * Prepare controller for a transaction and call omap_i2c_xfer_msg
636  * to do the work during IRQ processing.
637  */
638 static int
639 omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
640 {
641 	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
642 	int i;
643 	int r;
644 
645 	omap_i2c_unidle(dev);
646 
647 	r = omap_i2c_wait_for_bb(dev);
648 	if (r < 0)
649 		goto out;
650 
651 	if (dev->set_mpu_wkup_lat != NULL)
652 		dev->set_mpu_wkup_lat(dev->dev, dev->latency);
653 
654 	for (i = 0; i < num; i++) {
655 		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
656 		if (r != 0)
657 			break;
658 	}
659 
660 	if (dev->set_mpu_wkup_lat != NULL)
661 		dev->set_mpu_wkup_lat(dev->dev, -1);
662 
663 	if (r == 0)
664 		r = num;
665 
666 	omap_i2c_wait_for_bb(dev);
667 out:
668 	omap_i2c_idle(dev);
669 	return r;
670 }
671 
672 static u32
673 omap_i2c_func(struct i2c_adapter *adap)
674 {
675 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
676 }
677 
678 static inline void
679 omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
680 {
681 	dev->cmd_err |= err;
682 	complete(&dev->cmd_complete);
683 }
684 
685 static inline void
686 omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
687 {
688 	omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
689 }
690 
691 static inline void i2c_omap_errata_i207(struct omap_i2c_dev *dev, u16 stat)
692 {
693 	/*
694 	 * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
695 	 * Not applicable for OMAP4.
696 	 * Under certain rare conditions, RDR could be set again
697 	 * when the bus is busy, then ignore the interrupt and
698 	 * clear the interrupt.
699 	 */
700 	if (stat & OMAP_I2C_STAT_RDR) {
701 		/* Step 1: If RDR is set, clear it */
702 		omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
703 
704 		/* Step 2: */
705 		if (!(omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
706 						& OMAP_I2C_STAT_BB)) {
707 
708 			/* Step 3: */
709 			if (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
710 						& OMAP_I2C_STAT_RDR) {
711 				omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
712 				dev_dbg(dev->dev, "RDR when bus is busy.\n");
713 			}
714 
715 		}
716 	}
717 }
718 
719 /* rev1 devices are apparently only on some 15xx */
720 #ifdef CONFIG_ARCH_OMAP15XX
721 
722 static irqreturn_t
723 omap_i2c_rev1_isr(int this_irq, void *dev_id)
724 {
725 	struct omap_i2c_dev *dev = dev_id;
726 	u16 iv, w;
727 
728 	if (dev->idle)
729 		return IRQ_NONE;
730 
731 	iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
732 	switch (iv) {
733 	case 0x00:	/* None */
734 		break;
735 	case 0x01:	/* Arbitration lost */
736 		dev_err(dev->dev, "Arbitration lost\n");
737 		omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
738 		break;
739 	case 0x02:	/* No acknowledgement */
740 		omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
741 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
742 		break;
743 	case 0x03:	/* Register access ready */
744 		omap_i2c_complete_cmd(dev, 0);
745 		break;
746 	case 0x04:	/* Receive data ready */
747 		if (dev->buf_len) {
748 			w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
749 			*dev->buf++ = w;
750 			dev->buf_len--;
751 			if (dev->buf_len) {
752 				*dev->buf++ = w >> 8;
753 				dev->buf_len--;
754 			}
755 		} else
756 			dev_err(dev->dev, "RRDY IRQ while no data requested\n");
757 		break;
758 	case 0x05:	/* Transmit data ready */
759 		if (dev->buf_len) {
760 			w = *dev->buf++;
761 			dev->buf_len--;
762 			if (dev->buf_len) {
763 				w |= *dev->buf++ << 8;
764 				dev->buf_len--;
765 			}
766 			omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
767 		} else
768 			dev_err(dev->dev, "XRDY IRQ while no data to send\n");
769 		break;
770 	default:
771 		return IRQ_NONE;
772 	}
773 
774 	return IRQ_HANDLED;
775 }
776 #else
777 #define omap_i2c_rev1_isr		NULL
778 #endif
779 
780 /*
781  * OMAP3430 Errata 1.153: When an XRDY/XDR is hit, wait for XUDF before writing
782  * data to DATA_REG. Otherwise some data bytes can be lost while transferring
783  * them from the memory to the I2C interface.
784  */
785 static int errata_omap3_1p153(struct omap_i2c_dev *dev, u16 *stat, int *err)
786 {
787 	unsigned long timeout = 10000;
788 
789 	while (--timeout && !(*stat & OMAP_I2C_STAT_XUDF)) {
790 		if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
791 			omap_i2c_ack_stat(dev, *stat & (OMAP_I2C_STAT_XRDY |
792 							OMAP_I2C_STAT_XDR));
793 			*err |= OMAP_I2C_STAT_XUDF;
794 			return -ETIMEDOUT;
795 		}
796 
797 		cpu_relax();
798 		*stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
799 	}
800 
801 	if (!timeout) {
802 		dev_err(dev->dev, "timeout waiting on XUDF bit\n");
803 		return 0;
804 	}
805 
806 	return 0;
807 }
808 
809 static irqreturn_t
810 omap_i2c_isr(int this_irq, void *dev_id)
811 {
812 	struct omap_i2c_dev *dev = dev_id;
813 	u16 bits;
814 	u16 stat, w;
815 	int err, count = 0;
816 
817 	if (dev->idle)
818 		return IRQ_NONE;
819 
820 	bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
821 	while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
822 		dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
823 		if (count++ == 100) {
824 			dev_warn(dev->dev, "Too much work in one IRQ\n");
825 			break;
826 		}
827 
828 		err = 0;
829 complete:
830 		/*
831 		 * Ack the stat in one go, but [R/X]DR and [R/X]RDY should be
832 		 * acked after the data operation is complete.
833 		 * Ref: TRM SWPU114Q Figure 18-31
834 		 */
835 		omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat &
836 				~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
837 				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
838 
839 		if (stat & OMAP_I2C_STAT_NACK) {
840 			err |= OMAP_I2C_STAT_NACK;
841 			omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
842 					   OMAP_I2C_CON_STP);
843 		}
844 		if (stat & OMAP_I2C_STAT_AL) {
845 			dev_err(dev->dev, "Arbitration lost\n");
846 			err |= OMAP_I2C_STAT_AL;
847 		}
848 		/*
849 		 * ProDB0017052: Clear ARDY bit twice
850 		 */
851 		if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
852 					OMAP_I2C_STAT_AL)) {
853 			omap_i2c_ack_stat(dev, stat &
854 				(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
855 				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR |
856 				OMAP_I2C_STAT_ARDY));
857 			omap_i2c_complete_cmd(dev, err);
858 			return IRQ_HANDLED;
859 		}
860 		if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
861 			u8 num_bytes = 1;
862 
863 			if (dev->errata & I2C_OMAP_ERRATA_I207)
864 				i2c_omap_errata_i207(dev, stat);
865 
866 			if (dev->fifo_size) {
867 				if (stat & OMAP_I2C_STAT_RRDY)
868 					num_bytes = dev->fifo_size;
869 				else    /* read RXSTAT on RDR interrupt */
870 					num_bytes = (omap_i2c_read_reg(dev,
871 							OMAP_I2C_BUFSTAT_REG)
872 							>> 8) & 0x3F;
873 			}
874 			while (num_bytes) {
875 				num_bytes--;
876 				w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
877 				if (dev->buf_len) {
878 					*dev->buf++ = w;
879 					dev->buf_len--;
880 					/*
881 					 * Data reg in 2430, omap3 and
882 					 * omap4 is 8 bit wide
883 					 */
884 					if (cpu_class_is_omap1() ||
885 							cpu_is_omap2420()) {
886 						if (dev->buf_len) {
887 							*dev->buf++ = w >> 8;
888 							dev->buf_len--;
889 						}
890 					}
891 				} else {
892 					if (stat & OMAP_I2C_STAT_RRDY)
893 						dev_err(dev->dev,
894 							"RRDY IRQ while no data"
895 								" requested\n");
896 					if (stat & OMAP_I2C_STAT_RDR)
897 						dev_err(dev->dev,
898 							"RDR IRQ while no data"
899 								" requested\n");
900 					break;
901 				}
902 			}
903 			omap_i2c_ack_stat(dev,
904 				stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
905 			continue;
906 		}
907 		if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
908 			u8 num_bytes = 1;
909 			if (dev->fifo_size) {
910 				if (stat & OMAP_I2C_STAT_XRDY)
911 					num_bytes = dev->fifo_size;
912 				else    /* read TXSTAT on XDR interrupt */
913 					num_bytes = omap_i2c_read_reg(dev,
914 							OMAP_I2C_BUFSTAT_REG)
915 							& 0x3F;
916 			}
917 			while (num_bytes) {
918 				num_bytes--;
919 				w = 0;
920 				if (dev->buf_len) {
921 					w = *dev->buf++;
922 					dev->buf_len--;
923 					/*
924 					 * Data reg in 2430, omap3 and
925 					 * omap4 is 8 bit wide
926 					 */
927 					if (cpu_class_is_omap1() ||
928 							cpu_is_omap2420()) {
929 						if (dev->buf_len) {
930 							w |= *dev->buf++ << 8;
931 							dev->buf_len--;
932 						}
933 					}
934 				} else {
935 					if (stat & OMAP_I2C_STAT_XRDY)
936 						dev_err(dev->dev,
937 							"XRDY IRQ while no "
938 							"data to send\n");
939 					if (stat & OMAP_I2C_STAT_XDR)
940 						dev_err(dev->dev,
941 							"XDR IRQ while no "
942 							"data to send\n");
943 					break;
944 				}
945 
946 				if ((dev->errata & I2C_OMAP3_1P153) &&
947 				    errata_omap3_1p153(dev, &stat, &err))
948 					goto complete;
949 
950 				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
951 			}
952 			omap_i2c_ack_stat(dev,
953 				stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
954 			continue;
955 		}
956 		if (stat & OMAP_I2C_STAT_ROVR) {
957 			dev_err(dev->dev, "Receive overrun\n");
958 			dev->cmd_err |= OMAP_I2C_STAT_ROVR;
959 		}
960 		if (stat & OMAP_I2C_STAT_XUDF) {
961 			dev_err(dev->dev, "Transmit underflow\n");
962 			dev->cmd_err |= OMAP_I2C_STAT_XUDF;
963 		}
964 	}
965 
966 	return count ? IRQ_HANDLED : IRQ_NONE;
967 }
968 
969 static const struct i2c_algorithm omap_i2c_algo = {
970 	.master_xfer	= omap_i2c_xfer,
971 	.functionality	= omap_i2c_func,
972 };
973 
974 static int __devinit
975 omap_i2c_probe(struct platform_device *pdev)
976 {
977 	struct omap_i2c_dev	*dev;
978 	struct i2c_adapter	*adap;
979 	struct resource		*mem, *irq, *ioarea;
980 	struct omap_i2c_bus_platform_data *pdata = pdev->dev.platform_data;
981 	irq_handler_t isr;
982 	int r;
983 	u32 speed = 0;
984 
985 	/* NOTE: driver uses the static register mapping */
986 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
987 	if (!mem) {
988 		dev_err(&pdev->dev, "no mem resource?\n");
989 		return -ENODEV;
990 	}
991 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
992 	if (!irq) {
993 		dev_err(&pdev->dev, "no irq resource?\n");
994 		return -ENODEV;
995 	}
996 
997 	ioarea = request_mem_region(mem->start, resource_size(mem),
998 			pdev->name);
999 	if (!ioarea) {
1000 		dev_err(&pdev->dev, "I2C region already claimed\n");
1001 		return -EBUSY;
1002 	}
1003 
1004 	dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
1005 	if (!dev) {
1006 		r = -ENOMEM;
1007 		goto err_release_region;
1008 	}
1009 
1010 	if (pdata != NULL) {
1011 		speed = pdata->clkrate;
1012 		dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
1013 	} else {
1014 		speed = 100;	/* Default speed */
1015 		dev->set_mpu_wkup_lat = NULL;
1016 	}
1017 
1018 	dev->speed = speed;
1019 	dev->idle = 1;
1020 	dev->dev = &pdev->dev;
1021 	dev->irq = irq->start;
1022 	dev->base = ioremap(mem->start, resource_size(mem));
1023 	if (!dev->base) {
1024 		r = -ENOMEM;
1025 		goto err_free_mem;
1026 	}
1027 
1028 	platform_set_drvdata(pdev, dev);
1029 
1030 	if (cpu_is_omap7xx())
1031 		dev->reg_shift = 1;
1032 	else if (cpu_is_omap44xx())
1033 		dev->reg_shift = 0;
1034 	else
1035 		dev->reg_shift = 2;
1036 
1037 	if (cpu_is_omap44xx())
1038 		dev->regs = (u8 *) omap4_reg_map;
1039 	else
1040 		dev->regs = (u8 *) reg_map;
1041 
1042 	pm_runtime_enable(&pdev->dev);
1043 	omap_i2c_unidle(dev);
1044 
1045 	dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
1046 
1047 	if (dev->rev <= OMAP_I2C_REV_ON_3430)
1048 		dev->errata |= I2C_OMAP3_1P153;
1049 
1050 	if (!(cpu_class_is_omap1() || cpu_is_omap2420())) {
1051 		u16 s;
1052 
1053 		/* Set up the fifo size - Get total size */
1054 		s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
1055 		dev->fifo_size = 0x8 << s;
1056 
1057 		/*
1058 		 * Set up notification threshold as half the total available
1059 		 * size. This is to ensure that we can handle the status on int
1060 		 * call back latencies.
1061 		 */
1062 		if (dev->rev >= OMAP_I2C_REV_ON_4430) {
1063 			dev->fifo_size = 0;
1064 			dev->b_hw = 0; /* Disable hardware fixes */
1065 		} else {
1066 			dev->fifo_size = (dev->fifo_size / 2);
1067 			dev->b_hw = 1; /* Enable hardware fixes */
1068 		}
1069 		/* calculate wakeup latency constraint for MPU */
1070 		if (dev->set_mpu_wkup_lat != NULL)
1071 			dev->latency = (1000000 * dev->fifo_size) /
1072 				       (1000 * speed / 8);
1073 	}
1074 
1075 	/* reset ASAP, clearing any IRQs */
1076 	omap_i2c_init(dev);
1077 
1078 	isr = (dev->rev < OMAP_I2C_REV_2) ? omap_i2c_rev1_isr : omap_i2c_isr;
1079 	r = request_irq(dev->irq, isr, 0, pdev->name, dev);
1080 
1081 	if (r) {
1082 		dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
1083 		goto err_unuse_clocks;
1084 	}
1085 
1086 	dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
1087 		 pdev->id, dev->rev >> 4, dev->rev & 0xf, dev->speed);
1088 
1089 	omap_i2c_idle(dev);
1090 
1091 	adap = &dev->adapter;
1092 	i2c_set_adapdata(adap, dev);
1093 	adap->owner = THIS_MODULE;
1094 	adap->class = I2C_CLASS_HWMON;
1095 	strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
1096 	adap->algo = &omap_i2c_algo;
1097 	adap->dev.parent = &pdev->dev;
1098 
1099 	/* i2c device drivers may be active on return from add_adapter() */
1100 	adap->nr = pdev->id;
1101 	r = i2c_add_numbered_adapter(adap);
1102 	if (r) {
1103 		dev_err(dev->dev, "failure adding adapter\n");
1104 		goto err_free_irq;
1105 	}
1106 
1107 	return 0;
1108 
1109 err_free_irq:
1110 	free_irq(dev->irq, dev);
1111 err_unuse_clocks:
1112 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1113 	omap_i2c_idle(dev);
1114 	iounmap(dev->base);
1115 err_free_mem:
1116 	platform_set_drvdata(pdev, NULL);
1117 	kfree(dev);
1118 err_release_region:
1119 	release_mem_region(mem->start, resource_size(mem));
1120 
1121 	return r;
1122 }
1123 
1124 static int
1125 omap_i2c_remove(struct platform_device *pdev)
1126 {
1127 	struct omap_i2c_dev	*dev = platform_get_drvdata(pdev);
1128 	struct resource		*mem;
1129 
1130 	platform_set_drvdata(pdev, NULL);
1131 
1132 	free_irq(dev->irq, dev);
1133 	i2c_del_adapter(&dev->adapter);
1134 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1135 	iounmap(dev->base);
1136 	kfree(dev);
1137 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1138 	release_mem_region(mem->start, resource_size(mem));
1139 	return 0;
1140 }
1141 
1142 #ifdef CONFIG_SUSPEND
1143 static int omap_i2c_suspend(struct device *dev)
1144 {
1145 	if (!pm_runtime_suspended(dev))
1146 		if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
1147 			dev->bus->pm->runtime_suspend(dev);
1148 
1149 	return 0;
1150 }
1151 
1152 static int omap_i2c_resume(struct device *dev)
1153 {
1154 	if (!pm_runtime_suspended(dev))
1155 		if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
1156 			dev->bus->pm->runtime_resume(dev);
1157 
1158 	return 0;
1159 }
1160 
1161 static struct dev_pm_ops omap_i2c_pm_ops = {
1162 	.suspend = omap_i2c_suspend,
1163 	.resume = omap_i2c_resume,
1164 };
1165 #define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
1166 #else
1167 #define OMAP_I2C_PM_OPS NULL
1168 #endif
1169 
1170 static struct platform_driver omap_i2c_driver = {
1171 	.probe		= omap_i2c_probe,
1172 	.remove		= omap_i2c_remove,
1173 	.driver		= {
1174 		.name	= "omap_i2c",
1175 		.owner	= THIS_MODULE,
1176 		.pm	= OMAP_I2C_PM_OPS,
1177 	},
1178 };
1179 
1180 /* I2C may be needed to bring up other drivers */
1181 static int __init
1182 omap_i2c_init_driver(void)
1183 {
1184 	return platform_driver_register(&omap_i2c_driver);
1185 }
1186 subsys_initcall(omap_i2c_init_driver);
1187 
1188 static void __exit omap_i2c_exit_driver(void)
1189 {
1190 	platform_driver_unregister(&omap_i2c_driver);
1191 }
1192 module_exit(omap_i2c_exit_driver);
1193 
1194 MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
1195 MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
1196 MODULE_LICENSE("GPL");
1197 MODULE_ALIAS("platform:omap_i2c");
1198