xref: /linux/drivers/i2c/busses/i2c-omap.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 #include <linux/pinctrl/consumer.h>
47 
48 /* I2C controller revisions */
49 #define OMAP_I2C_OMAP1_REV_2		0x20
50 
51 /* I2C controller revisions present on specific hardware */
52 #define OMAP_I2C_REV_ON_2430		0x00000036
53 #define OMAP_I2C_REV_ON_3430_3530	0x0000003C
54 #define OMAP_I2C_REV_ON_3630		0x00000040
55 #define OMAP_I2C_REV_ON_4430_PLUS	0x50400002
56 
57 /* timeout waiting for the controller to respond */
58 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
59 
60 /* timeout for pm runtime autosuspend */
61 #define OMAP_I2C_PM_TIMEOUT		1000	/* ms */
62 
63 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
64 enum {
65 	OMAP_I2C_REV_REG = 0,
66 	OMAP_I2C_IE_REG,
67 	OMAP_I2C_STAT_REG,
68 	OMAP_I2C_IV_REG,
69 	OMAP_I2C_WE_REG,
70 	OMAP_I2C_SYSS_REG,
71 	OMAP_I2C_BUF_REG,
72 	OMAP_I2C_CNT_REG,
73 	OMAP_I2C_DATA_REG,
74 	OMAP_I2C_SYSC_REG,
75 	OMAP_I2C_CON_REG,
76 	OMAP_I2C_OA_REG,
77 	OMAP_I2C_SA_REG,
78 	OMAP_I2C_PSC_REG,
79 	OMAP_I2C_SCLL_REG,
80 	OMAP_I2C_SCLH_REG,
81 	OMAP_I2C_SYSTEST_REG,
82 	OMAP_I2C_BUFSTAT_REG,
83 	/* only on OMAP4430 */
84 	OMAP_I2C_IP_V2_REVNB_LO,
85 	OMAP_I2C_IP_V2_REVNB_HI,
86 	OMAP_I2C_IP_V2_IRQSTATUS_RAW,
87 	OMAP_I2C_IP_V2_IRQENABLE_SET,
88 	OMAP_I2C_IP_V2_IRQENABLE_CLR,
89 };
90 
91 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
92 #define OMAP_I2C_IE_XDR		(1 << 14)	/* TX Buffer drain int enable */
93 #define OMAP_I2C_IE_RDR		(1 << 13)	/* RX Buffer drain int enable */
94 #define OMAP_I2C_IE_XRDY	(1 << 4)	/* TX data ready int enable */
95 #define OMAP_I2C_IE_RRDY	(1 << 3)	/* RX data ready int enable */
96 #define OMAP_I2C_IE_ARDY	(1 << 2)	/* Access ready int enable */
97 #define OMAP_I2C_IE_NACK	(1 << 1)	/* No ack interrupt enable */
98 #define OMAP_I2C_IE_AL		(1 << 0)	/* Arbitration lost int ena */
99 
100 /* I2C Status Register (OMAP_I2C_STAT): */
101 #define OMAP_I2C_STAT_XDR	(1 << 14)	/* TX Buffer draining */
102 #define OMAP_I2C_STAT_RDR	(1 << 13)	/* RX Buffer draining */
103 #define OMAP_I2C_STAT_BB	(1 << 12)	/* Bus busy */
104 #define OMAP_I2C_STAT_ROVR	(1 << 11)	/* Receive overrun */
105 #define OMAP_I2C_STAT_XUDF	(1 << 10)	/* Transmit underflow */
106 #define OMAP_I2C_STAT_AAS	(1 << 9)	/* Address as slave */
107 #define OMAP_I2C_STAT_AD0	(1 << 8)	/* Address zero */
108 #define OMAP_I2C_STAT_XRDY	(1 << 4)	/* Transmit data ready */
109 #define OMAP_I2C_STAT_RRDY	(1 << 3)	/* Receive data ready */
110 #define OMAP_I2C_STAT_ARDY	(1 << 2)	/* Register access ready */
111 #define OMAP_I2C_STAT_NACK	(1 << 1)	/* No ack interrupt enable */
112 #define OMAP_I2C_STAT_AL	(1 << 0)	/* Arbitration lost int ena */
113 
114 /* I2C WE wakeup enable register */
115 #define OMAP_I2C_WE_XDR_WE	(1 << 14)	/* TX drain wakup */
116 #define OMAP_I2C_WE_RDR_WE	(1 << 13)	/* RX drain wakeup */
117 #define OMAP_I2C_WE_AAS_WE	(1 << 9)	/* Address as slave wakeup*/
118 #define OMAP_I2C_WE_BF_WE	(1 << 8)	/* Bus free wakeup */
119 #define OMAP_I2C_WE_STC_WE	(1 << 6)	/* Start condition wakeup */
120 #define OMAP_I2C_WE_GC_WE	(1 << 5)	/* General call wakeup */
121 #define OMAP_I2C_WE_DRDY_WE	(1 << 3)	/* TX/RX data ready wakeup */
122 #define OMAP_I2C_WE_ARDY_WE	(1 << 2)	/* Reg access ready wakeup */
123 #define OMAP_I2C_WE_NACK_WE	(1 << 1)	/* No acknowledgment wakeup */
124 #define OMAP_I2C_WE_AL_WE	(1 << 0)	/* Arbitration lost wakeup */
125 
126 #define OMAP_I2C_WE_ALL		(OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
127 				OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
128 				OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
129 				OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
130 				OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
131 
132 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
133 #define OMAP_I2C_BUF_RDMA_EN	(1 << 15)	/* RX DMA channel enable */
134 #define OMAP_I2C_BUF_RXFIF_CLR	(1 << 14)	/* RX FIFO Clear */
135 #define OMAP_I2C_BUF_XDMA_EN	(1 << 7)	/* TX DMA channel enable */
136 #define OMAP_I2C_BUF_TXFIF_CLR	(1 << 6)	/* TX FIFO Clear */
137 
138 /* I2C Configuration Register (OMAP_I2C_CON): */
139 #define OMAP_I2C_CON_EN		(1 << 15)	/* I2C module enable */
140 #define OMAP_I2C_CON_BE		(1 << 14)	/* Big endian mode */
141 #define OMAP_I2C_CON_OPMODE_HS	(1 << 12)	/* High Speed support */
142 #define OMAP_I2C_CON_STB	(1 << 11)	/* Start byte mode (master) */
143 #define OMAP_I2C_CON_MST	(1 << 10)	/* Master/slave mode */
144 #define OMAP_I2C_CON_TRX	(1 << 9)	/* TX/RX mode (master only) */
145 #define OMAP_I2C_CON_XA		(1 << 8)	/* Expand address */
146 #define OMAP_I2C_CON_RM		(1 << 2)	/* Repeat mode (master only) */
147 #define OMAP_I2C_CON_STP	(1 << 1)	/* Stop cond (master only) */
148 #define OMAP_I2C_CON_STT	(1 << 0)	/* Start condition (master) */
149 
150 /* I2C SCL time value when Master */
151 #define OMAP_I2C_SCLL_HSSCLL	8
152 #define OMAP_I2C_SCLH_HSSCLH	8
153 
154 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
155 #ifdef DEBUG
156 #define OMAP_I2C_SYSTEST_ST_EN		(1 << 15)	/* System test enable */
157 #define OMAP_I2C_SYSTEST_FREE		(1 << 14)	/* Free running mode */
158 #define OMAP_I2C_SYSTEST_TMODE_MASK	(3 << 12)	/* Test mode select */
159 #define OMAP_I2C_SYSTEST_TMODE_SHIFT	(12)		/* Test mode select */
160 #define OMAP_I2C_SYSTEST_SCL_I		(1 << 3)	/* SCL line sense in */
161 #define OMAP_I2C_SYSTEST_SCL_O		(1 << 2)	/* SCL line drive out */
162 #define OMAP_I2C_SYSTEST_SDA_I		(1 << 1)	/* SDA line sense in */
163 #define OMAP_I2C_SYSTEST_SDA_O		(1 << 0)	/* SDA line drive out */
164 #endif
165 
166 /* OCP_SYSSTATUS bit definitions */
167 #define SYSS_RESETDONE_MASK		(1 << 0)
168 
169 /* OCP_SYSCONFIG bit definitions */
170 #define SYSC_CLOCKACTIVITY_MASK		(0x3 << 8)
171 #define SYSC_SIDLEMODE_MASK		(0x3 << 3)
172 #define SYSC_ENAWAKEUP_MASK		(1 << 2)
173 #define SYSC_SOFTRESET_MASK		(1 << 1)
174 #define SYSC_AUTOIDLE_MASK		(1 << 0)
175 
176 #define SYSC_IDLEMODE_SMART		0x2
177 #define SYSC_CLOCKACTIVITY_FCLK		0x2
178 
179 /* Errata definitions */
180 #define I2C_OMAP_ERRATA_I207		(1 << 0)
181 #define I2C_OMAP_ERRATA_I462		(1 << 1)
182 
183 struct omap_i2c_dev {
184 	spinlock_t		lock;		/* IRQ synchronization */
185 	struct device		*dev;
186 	void __iomem		*base;		/* virtual */
187 	int			irq;
188 	int			reg_shift;      /* bit shift for I2C register addresses */
189 	struct completion	cmd_complete;
190 	struct resource		*ioarea;
191 	u32			latency;	/* maximum mpu wkup latency */
192 	void			(*set_mpu_wkup_lat)(struct device *dev,
193 						    long latency);
194 	u32			speed;		/* Speed of bus in kHz */
195 	u32			flags;
196 	u16			cmd_err;
197 	u8			*buf;
198 	u8			*regs;
199 	size_t			buf_len;
200 	struct i2c_adapter	adapter;
201 	u8			threshold;
202 	u8			fifo_size;	/* use as flag and value
203 						 * fifo_size==0 implies no fifo
204 						 * if set, should be trsh+1
205 						 */
206 	u32			rev;
207 	unsigned		b_hw:1;		/* bad h/w fixes */
208 	unsigned		receiver:1;	/* true when we're in receiver mode */
209 	u16			iestate;	/* Saved interrupt register */
210 	u16			pscstate;
211 	u16			scllstate;
212 	u16			sclhstate;
213 	u16			syscstate;
214 	u16			westate;
215 	u16			errata;
216 
217 	struct pinctrl		*pins;
218 };
219 
220 static const u8 reg_map_ip_v1[] = {
221 	[OMAP_I2C_REV_REG] = 0x00,
222 	[OMAP_I2C_IE_REG] = 0x01,
223 	[OMAP_I2C_STAT_REG] = 0x02,
224 	[OMAP_I2C_IV_REG] = 0x03,
225 	[OMAP_I2C_WE_REG] = 0x03,
226 	[OMAP_I2C_SYSS_REG] = 0x04,
227 	[OMAP_I2C_BUF_REG] = 0x05,
228 	[OMAP_I2C_CNT_REG] = 0x06,
229 	[OMAP_I2C_DATA_REG] = 0x07,
230 	[OMAP_I2C_SYSC_REG] = 0x08,
231 	[OMAP_I2C_CON_REG] = 0x09,
232 	[OMAP_I2C_OA_REG] = 0x0a,
233 	[OMAP_I2C_SA_REG] = 0x0b,
234 	[OMAP_I2C_PSC_REG] = 0x0c,
235 	[OMAP_I2C_SCLL_REG] = 0x0d,
236 	[OMAP_I2C_SCLH_REG] = 0x0e,
237 	[OMAP_I2C_SYSTEST_REG] = 0x0f,
238 	[OMAP_I2C_BUFSTAT_REG] = 0x10,
239 };
240 
241 static const u8 reg_map_ip_v2[] = {
242 	[OMAP_I2C_REV_REG] = 0x04,
243 	[OMAP_I2C_IE_REG] = 0x2c,
244 	[OMAP_I2C_STAT_REG] = 0x28,
245 	[OMAP_I2C_IV_REG] = 0x34,
246 	[OMAP_I2C_WE_REG] = 0x34,
247 	[OMAP_I2C_SYSS_REG] = 0x90,
248 	[OMAP_I2C_BUF_REG] = 0x94,
249 	[OMAP_I2C_CNT_REG] = 0x98,
250 	[OMAP_I2C_DATA_REG] = 0x9c,
251 	[OMAP_I2C_SYSC_REG] = 0x10,
252 	[OMAP_I2C_CON_REG] = 0xa4,
253 	[OMAP_I2C_OA_REG] = 0xa8,
254 	[OMAP_I2C_SA_REG] = 0xac,
255 	[OMAP_I2C_PSC_REG] = 0xb0,
256 	[OMAP_I2C_SCLL_REG] = 0xb4,
257 	[OMAP_I2C_SCLH_REG] = 0xb8,
258 	[OMAP_I2C_SYSTEST_REG] = 0xbC,
259 	[OMAP_I2C_BUFSTAT_REG] = 0xc0,
260 	[OMAP_I2C_IP_V2_REVNB_LO] = 0x00,
261 	[OMAP_I2C_IP_V2_REVNB_HI] = 0x04,
262 	[OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24,
263 	[OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c,
264 	[OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
265 };
266 
267 static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
268 				      int reg, u16 val)
269 {
270 	__raw_writew(val, i2c_dev->base +
271 			(i2c_dev->regs[reg] << i2c_dev->reg_shift));
272 }
273 
274 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
275 {
276 	return __raw_readw(i2c_dev->base +
277 				(i2c_dev->regs[reg] << i2c_dev->reg_shift));
278 }
279 
280 static void __omap_i2c_init(struct omap_i2c_dev *dev)
281 {
282 
283 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
284 
285 	/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
286 	omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
287 
288 	/* SCL low and high time values */
289 	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
290 	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
291 	if (dev->rev >= OMAP_I2C_REV_ON_3430_3530)
292 		omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
293 
294 	/* Take the I2C module out of reset: */
295 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
296 
297 	/*
298 	 * Don't write to this register if the IE state is 0 as it can
299 	 * cause deadlock.
300 	 */
301 	if (dev->iestate)
302 		omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
303 }
304 
305 static int omap_i2c_reset(struct omap_i2c_dev *dev)
306 {
307 	unsigned long timeout;
308 	u16 sysc;
309 
310 	if (dev->rev >= OMAP_I2C_OMAP1_REV_2) {
311 		sysc = omap_i2c_read_reg(dev, OMAP_I2C_SYSC_REG);
312 
313 		/* Disable I2C controller before soft reset */
314 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
315 			omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) &
316 				~(OMAP_I2C_CON_EN));
317 
318 		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
319 		/* For some reason we need to set the EN bit before the
320 		 * reset done bit gets set. */
321 		timeout = jiffies + OMAP_I2C_TIMEOUT;
322 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
323 		while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
324 			 SYSS_RESETDONE_MASK)) {
325 			if (time_after(jiffies, timeout)) {
326 				dev_warn(dev->dev, "timeout waiting "
327 						"for controller reset\n");
328 				return -ETIMEDOUT;
329 			}
330 			msleep(1);
331 		}
332 
333 		/* SYSC register is cleared by the reset; rewrite it */
334 		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, sysc);
335 
336 	}
337 	return 0;
338 }
339 
340 static int omap_i2c_init(struct omap_i2c_dev *dev)
341 {
342 	u16 psc = 0, scll = 0, sclh = 0;
343 	u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
344 	unsigned long fclk_rate = 12000000;
345 	unsigned long internal_clk = 0;
346 	struct clk *fclk;
347 
348 	if (dev->rev >= OMAP_I2C_REV_ON_3430_3530) {
349 		/*
350 		 * Enabling all wakup sources to stop I2C freezing on
351 		 * WFI instruction.
352 		 * REVISIT: Some wkup sources might not be needed.
353 		 */
354 		dev->westate = OMAP_I2C_WE_ALL;
355 	}
356 
357 	if (dev->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {
358 		/*
359 		 * The I2C functional clock is the armxor_ck, so there's
360 		 * no need to get "armxor_ck" separately.  Now, if OMAP2420
361 		 * always returns 12MHz for the functional clock, we can
362 		 * do this bit unconditionally.
363 		 */
364 		fclk = clk_get(dev->dev, "fck");
365 		fclk_rate = clk_get_rate(fclk);
366 		clk_put(fclk);
367 
368 		/* TRM for 5912 says the I2C clock must be prescaled to be
369 		 * between 7 - 12 MHz. The XOR input clock is typically
370 		 * 12, 13 or 19.2 MHz. So we should have code that produces:
371 		 *
372 		 * XOR MHz	Divider		Prescaler
373 		 * 12		1		0
374 		 * 13		2		1
375 		 * 19.2		2		1
376 		 */
377 		if (fclk_rate > 12000000)
378 			psc = fclk_rate / 12000000;
379 	}
380 
381 	if (!(dev->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) {
382 
383 		/*
384 		 * HSI2C controller internal clk rate should be 19.2 Mhz for
385 		 * HS and for all modes on 2430. On 34xx we can use lower rate
386 		 * to get longer filter period for better noise suppression.
387 		 * The filter is iclk (fclk for HS) period.
388 		 */
389 		if (dev->speed > 400 ||
390 			       dev->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK)
391 			internal_clk = 19200;
392 		else if (dev->speed > 100)
393 			internal_clk = 9600;
394 		else
395 			internal_clk = 4000;
396 		fclk = clk_get(dev->dev, "fck");
397 		fclk_rate = clk_get_rate(fclk) / 1000;
398 		clk_put(fclk);
399 
400 		/* Compute prescaler divisor */
401 		psc = fclk_rate / internal_clk;
402 		psc = psc - 1;
403 
404 		/* If configured for High Speed */
405 		if (dev->speed > 400) {
406 			unsigned long scl;
407 
408 			/* For first phase of HS mode */
409 			scl = internal_clk / 400;
410 			fsscll = scl - (scl / 3) - 7;
411 			fssclh = (scl / 3) - 5;
412 
413 			/* For second phase of HS mode */
414 			scl = fclk_rate / dev->speed;
415 			hsscll = scl - (scl / 3) - 7;
416 			hssclh = (scl / 3) - 5;
417 		} else if (dev->speed > 100) {
418 			unsigned long scl;
419 
420 			/* Fast mode */
421 			scl = internal_clk / dev->speed;
422 			fsscll = scl - (scl / 3) - 7;
423 			fssclh = (scl / 3) - 5;
424 		} else {
425 			/* Standard mode */
426 			fsscll = internal_clk / (dev->speed * 2) - 7;
427 			fssclh = internal_clk / (dev->speed * 2) - 5;
428 		}
429 		scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
430 		sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
431 	} else {
432 		/* Program desired operating rate */
433 		fclk_rate /= (psc + 1) * 1000;
434 		if (psc > 2)
435 			psc = 2;
436 		scll = fclk_rate / (dev->speed * 2) - 7 + psc;
437 		sclh = fclk_rate / (dev->speed * 2) - 7 + psc;
438 	}
439 
440 	dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
441 			OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
442 			OMAP_I2C_IE_AL)  | ((dev->fifo_size) ?
443 				(OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
444 
445 	dev->pscstate = psc;
446 	dev->scllstate = scll;
447 	dev->sclhstate = sclh;
448 
449 	__omap_i2c_init(dev);
450 
451 	return 0;
452 }
453 
454 /*
455  * Waiting on Bus Busy
456  */
457 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
458 {
459 	unsigned long timeout;
460 
461 	timeout = jiffies + OMAP_I2C_TIMEOUT;
462 	while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
463 		if (time_after(jiffies, timeout)) {
464 			dev_warn(dev->dev, "timeout waiting for bus ready\n");
465 			return -ETIMEDOUT;
466 		}
467 		msleep(1);
468 	}
469 
470 	return 0;
471 }
472 
473 static void omap_i2c_resize_fifo(struct omap_i2c_dev *dev, u8 size, bool is_rx)
474 {
475 	u16		buf;
476 
477 	if (dev->flags & OMAP_I2C_FLAG_NO_FIFO)
478 		return;
479 
480 	/*
481 	 * Set up notification threshold based on message size. We're doing
482 	 * this to try and avoid draining feature as much as possible. Whenever
483 	 * we have big messages to transfer (bigger than our total fifo size)
484 	 * then we might use draining feature to transfer the remaining bytes.
485 	 */
486 
487 	dev->threshold = clamp(size, (u8) 1, dev->fifo_size);
488 
489 	buf = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
490 
491 	if (is_rx) {
492 		/* Clear RX Threshold */
493 		buf &= ~(0x3f << 8);
494 		buf |= ((dev->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR;
495 	} else {
496 		/* Clear TX Threshold */
497 		buf &= ~0x3f;
498 		buf |= (dev->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR;
499 	}
500 
501 	omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
502 
503 	if (dev->rev < OMAP_I2C_REV_ON_3630)
504 		dev->b_hw = 1; /* Enable hardware fixes */
505 
506 	/* calculate wakeup latency constraint for MPU */
507 	if (dev->set_mpu_wkup_lat != NULL)
508 		dev->latency = (1000000 * dev->threshold) /
509 			(1000 * dev->speed / 8);
510 }
511 
512 /*
513  * Low level master read/write transaction.
514  */
515 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
516 			     struct i2c_msg *msg, int stop)
517 {
518 	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
519 	unsigned long timeout;
520 	u16 w;
521 
522 	dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
523 		msg->addr, msg->len, msg->flags, stop);
524 
525 	if (msg->len == 0)
526 		return -EINVAL;
527 
528 	dev->receiver = !!(msg->flags & I2C_M_RD);
529 	omap_i2c_resize_fifo(dev, msg->len, dev->receiver);
530 
531 	omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
532 
533 	/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
534 	dev->buf = msg->buf;
535 	dev->buf_len = msg->len;
536 
537 	/* make sure writes to dev->buf_len are ordered */
538 	barrier();
539 
540 	omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
541 
542 	/* Clear the FIFO Buffers */
543 	w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
544 	w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
545 	omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w);
546 
547 	INIT_COMPLETION(dev->cmd_complete);
548 	dev->cmd_err = 0;
549 
550 	w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
551 
552 	/* High speed configuration */
553 	if (dev->speed > 400)
554 		w |= OMAP_I2C_CON_OPMODE_HS;
555 
556 	if (msg->flags & I2C_M_STOP)
557 		stop = 1;
558 	if (msg->flags & I2C_M_TEN)
559 		w |= OMAP_I2C_CON_XA;
560 	if (!(msg->flags & I2C_M_RD))
561 		w |= OMAP_I2C_CON_TRX;
562 
563 	if (!dev->b_hw && stop)
564 		w |= OMAP_I2C_CON_STP;
565 
566 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
567 
568 	/*
569 	 * Don't write stt and stp together on some hardware.
570 	 */
571 	if (dev->b_hw && stop) {
572 		unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
573 		u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
574 		while (con & OMAP_I2C_CON_STT) {
575 			con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
576 
577 			/* Let the user know if i2c is in a bad state */
578 			if (time_after(jiffies, delay)) {
579 				dev_err(dev->dev, "controller timed out "
580 				"waiting for start condition to finish\n");
581 				return -ETIMEDOUT;
582 			}
583 			cpu_relax();
584 		}
585 
586 		w |= OMAP_I2C_CON_STP;
587 		w &= ~OMAP_I2C_CON_STT;
588 		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
589 	}
590 
591 	/*
592 	 * REVISIT: We should abort the transfer on signals, but the bus goes
593 	 * into arbitration and we're currently unable to recover from it.
594 	 */
595 	timeout = wait_for_completion_timeout(&dev->cmd_complete,
596 						OMAP_I2C_TIMEOUT);
597 	if (timeout == 0) {
598 		dev_err(dev->dev, "controller timed out\n");
599 		omap_i2c_reset(dev);
600 		__omap_i2c_init(dev);
601 		return -ETIMEDOUT;
602 	}
603 
604 	if (likely(!dev->cmd_err))
605 		return 0;
606 
607 	/* We have an error */
608 	if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
609 			    OMAP_I2C_STAT_XUDF)) {
610 		omap_i2c_reset(dev);
611 		__omap_i2c_init(dev);
612 		return -EIO;
613 	}
614 
615 	if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
616 		if (msg->flags & I2C_M_IGNORE_NAK)
617 			return 0;
618 		if (stop) {
619 			w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
620 			w |= OMAP_I2C_CON_STP;
621 			omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
622 		}
623 		return -EREMOTEIO;
624 	}
625 	return -EIO;
626 }
627 
628 
629 /*
630  * Prepare controller for a transaction and call omap_i2c_xfer_msg
631  * to do the work during IRQ processing.
632  */
633 static int
634 omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
635 {
636 	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
637 	int i;
638 	int r;
639 
640 	r = pm_runtime_get_sync(dev->dev);
641 	if (IS_ERR_VALUE(r))
642 		goto out;
643 
644 	r = omap_i2c_wait_for_bb(dev);
645 	if (r < 0)
646 		goto out;
647 
648 	if (dev->set_mpu_wkup_lat != NULL)
649 		dev->set_mpu_wkup_lat(dev->dev, dev->latency);
650 
651 	for (i = 0; i < num; i++) {
652 		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
653 		if (r != 0)
654 			break;
655 	}
656 
657 	if (r == 0)
658 		r = num;
659 
660 	omap_i2c_wait_for_bb(dev);
661 
662 	if (dev->set_mpu_wkup_lat != NULL)
663 		dev->set_mpu_wkup_lat(dev->dev, -1);
664 
665 out:
666 	pm_runtime_mark_last_busy(dev->dev);
667 	pm_runtime_put_autosuspend(dev->dev);
668 	return r;
669 }
670 
671 static u32
672 omap_i2c_func(struct i2c_adapter *adap)
673 {
674 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
675 	       I2C_FUNC_PROTOCOL_MANGLING;
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_omap1_isr(int this_irq, void *dev_id)
724 {
725 	struct omap_i2c_dev *dev = dev_id;
726 	u16 iv, w;
727 
728 	if (pm_runtime_suspended(dev->dev))
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_omap1_isr		NULL
778 #endif
779 
780 /*
781  * OMAP3430 Errata i462: 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_i462(struct omap_i2c_dev *dev)
786 {
787 	unsigned long timeout = 10000;
788 	u16 stat;
789 
790 	do {
791 		stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
792 		if (stat & OMAP_I2C_STAT_XUDF)
793 			break;
794 
795 		if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
796 			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
797 							OMAP_I2C_STAT_XDR));
798 			if (stat & OMAP_I2C_STAT_NACK) {
799 				dev->cmd_err |= OMAP_I2C_STAT_NACK;
800 				omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
801 			}
802 
803 			if (stat & OMAP_I2C_STAT_AL) {
804 				dev_err(dev->dev, "Arbitration lost\n");
805 				dev->cmd_err |= OMAP_I2C_STAT_AL;
806 				omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
807 			}
808 
809 			return -EIO;
810 		}
811 
812 		cpu_relax();
813 	} while (--timeout);
814 
815 	if (!timeout) {
816 		dev_err(dev->dev, "timeout waiting on XUDF bit\n");
817 		return 0;
818 	}
819 
820 	return 0;
821 }
822 
823 static void omap_i2c_receive_data(struct omap_i2c_dev *dev, u8 num_bytes,
824 		bool is_rdr)
825 {
826 	u16		w;
827 
828 	while (num_bytes--) {
829 		w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
830 		*dev->buf++ = w;
831 		dev->buf_len--;
832 
833 		/*
834 		 * Data reg in 2430, omap3 and
835 		 * omap4 is 8 bit wide
836 		 */
837 		if (dev->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
838 			*dev->buf++ = w >> 8;
839 			dev->buf_len--;
840 		}
841 	}
842 }
843 
844 static int omap_i2c_transmit_data(struct omap_i2c_dev *dev, u8 num_bytes,
845 		bool is_xdr)
846 {
847 	u16		w;
848 
849 	while (num_bytes--) {
850 		w = *dev->buf++;
851 		dev->buf_len--;
852 
853 		/*
854 		 * Data reg in 2430, omap3 and
855 		 * omap4 is 8 bit wide
856 		 */
857 		if (dev->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
858 			w |= *dev->buf++ << 8;
859 			dev->buf_len--;
860 		}
861 
862 		if (dev->errata & I2C_OMAP_ERRATA_I462) {
863 			int ret;
864 
865 			ret = errata_omap3_i462(dev);
866 			if (ret < 0)
867 				return ret;
868 		}
869 
870 		omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
871 	}
872 
873 	return 0;
874 }
875 
876 static irqreturn_t
877 omap_i2c_isr(int irq, void *dev_id)
878 {
879 	struct omap_i2c_dev *dev = dev_id;
880 	irqreturn_t ret = IRQ_HANDLED;
881 	u16 mask;
882 	u16 stat;
883 
884 	spin_lock(&dev->lock);
885 	mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
886 	stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
887 
888 	if (stat & mask)
889 		ret = IRQ_WAKE_THREAD;
890 
891 	spin_unlock(&dev->lock);
892 
893 	return ret;
894 }
895 
896 static irqreturn_t
897 omap_i2c_isr_thread(int this_irq, void *dev_id)
898 {
899 	struct omap_i2c_dev *dev = dev_id;
900 	unsigned long flags;
901 	u16 bits;
902 	u16 stat;
903 	int err = 0, count = 0;
904 
905 	spin_lock_irqsave(&dev->lock, flags);
906 	do {
907 		bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
908 		stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
909 		stat &= bits;
910 
911 		/* If we're in receiver mode, ignore XDR/XRDY */
912 		if (dev->receiver)
913 			stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY);
914 		else
915 			stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY);
916 
917 		if (!stat) {
918 			/* my work here is done */
919 			goto out;
920 		}
921 
922 		dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
923 		if (count++ == 100) {
924 			dev_warn(dev->dev, "Too much work in one IRQ\n");
925 			break;
926 		}
927 
928 		if (stat & OMAP_I2C_STAT_NACK) {
929 			err |= OMAP_I2C_STAT_NACK;
930 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
931 			break;
932 		}
933 
934 		if (stat & OMAP_I2C_STAT_AL) {
935 			dev_err(dev->dev, "Arbitration lost\n");
936 			err |= OMAP_I2C_STAT_AL;
937 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_AL);
938 			break;
939 		}
940 
941 		/*
942 		 * ProDB0017052: Clear ARDY bit twice
943 		 */
944 		if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
945 					OMAP_I2C_STAT_AL)) {
946 			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |
947 						OMAP_I2C_STAT_RDR |
948 						OMAP_I2C_STAT_XRDY |
949 						OMAP_I2C_STAT_XDR |
950 						OMAP_I2C_STAT_ARDY));
951 			break;
952 		}
953 
954 		if (stat & OMAP_I2C_STAT_RDR) {
955 			u8 num_bytes = 1;
956 
957 			if (dev->fifo_size)
958 				num_bytes = dev->buf_len;
959 
960 			omap_i2c_receive_data(dev, num_bytes, true);
961 
962 			if (dev->errata & I2C_OMAP_ERRATA_I207)
963 				i2c_omap_errata_i207(dev, stat);
964 
965 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
966 			break;
967 		}
968 
969 		if (stat & OMAP_I2C_STAT_RRDY) {
970 			u8 num_bytes = 1;
971 
972 			if (dev->threshold)
973 				num_bytes = dev->threshold;
974 
975 			omap_i2c_receive_data(dev, num_bytes, false);
976 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
977 			continue;
978 		}
979 
980 		if (stat & OMAP_I2C_STAT_XDR) {
981 			u8 num_bytes = 1;
982 			int ret;
983 
984 			if (dev->fifo_size)
985 				num_bytes = dev->buf_len;
986 
987 			ret = omap_i2c_transmit_data(dev, num_bytes, true);
988 			if (ret < 0)
989 				break;
990 
991 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XDR);
992 			break;
993 		}
994 
995 		if (stat & OMAP_I2C_STAT_XRDY) {
996 			u8 num_bytes = 1;
997 			int ret;
998 
999 			if (dev->threshold)
1000 				num_bytes = dev->threshold;
1001 
1002 			ret = omap_i2c_transmit_data(dev, num_bytes, false);
1003 			if (ret < 0)
1004 				break;
1005 
1006 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
1007 			continue;
1008 		}
1009 
1010 		if (stat & OMAP_I2C_STAT_ROVR) {
1011 			dev_err(dev->dev, "Receive overrun\n");
1012 			err |= OMAP_I2C_STAT_ROVR;
1013 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ROVR);
1014 			break;
1015 		}
1016 
1017 		if (stat & OMAP_I2C_STAT_XUDF) {
1018 			dev_err(dev->dev, "Transmit underflow\n");
1019 			err |= OMAP_I2C_STAT_XUDF;
1020 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XUDF);
1021 			break;
1022 		}
1023 	} while (stat);
1024 
1025 	omap_i2c_complete_cmd(dev, err);
1026 
1027 out:
1028 	spin_unlock_irqrestore(&dev->lock, flags);
1029 
1030 	return IRQ_HANDLED;
1031 }
1032 
1033 static const struct i2c_algorithm omap_i2c_algo = {
1034 	.master_xfer	= omap_i2c_xfer,
1035 	.functionality	= omap_i2c_func,
1036 };
1037 
1038 #ifdef CONFIG_OF
1039 static struct omap_i2c_bus_platform_data omap3_pdata = {
1040 	.rev = OMAP_I2C_IP_VERSION_1,
1041 	.flags = OMAP_I2C_FLAG_BUS_SHIFT_2,
1042 };
1043 
1044 static struct omap_i2c_bus_platform_data omap4_pdata = {
1045 	.rev = OMAP_I2C_IP_VERSION_2,
1046 };
1047 
1048 static const struct of_device_id omap_i2c_of_match[] = {
1049 	{
1050 		.compatible = "ti,omap4-i2c",
1051 		.data = &omap4_pdata,
1052 	},
1053 	{
1054 		.compatible = "ti,omap3-i2c",
1055 		.data = &omap3_pdata,
1056 	},
1057 	{ },
1058 };
1059 MODULE_DEVICE_TABLE(of, omap_i2c_of_match);
1060 #endif
1061 
1062 #define OMAP_I2C_SCHEME(rev)		((rev & 0xc000) >> 14)
1063 
1064 #define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4)
1065 #define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf)
1066 
1067 #define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7)
1068 #define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f)
1069 #define OMAP_I2C_SCHEME_0		0
1070 #define OMAP_I2C_SCHEME_1		1
1071 
1072 static int __devinit
1073 omap_i2c_probe(struct platform_device *pdev)
1074 {
1075 	struct omap_i2c_dev	*dev;
1076 	struct i2c_adapter	*adap;
1077 	struct resource		*mem;
1078 	const struct omap_i2c_bus_platform_data *pdata =
1079 		pdev->dev.platform_data;
1080 	struct device_node	*node = pdev->dev.of_node;
1081 	const struct of_device_id *match;
1082 	int irq;
1083 	int r;
1084 	u32 rev;
1085 	u16 minor, major, scheme;
1086 
1087 	/* NOTE: driver uses the static register mapping */
1088 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1089 	if (!mem) {
1090 		dev_err(&pdev->dev, "no mem resource?\n");
1091 		return -ENODEV;
1092 	}
1093 
1094 	irq = platform_get_irq(pdev, 0);
1095 	if (irq < 0) {
1096 		dev_err(&pdev->dev, "no irq resource?\n");
1097 		return irq;
1098 	}
1099 
1100 	dev = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL);
1101 	if (!dev) {
1102 		dev_err(&pdev->dev, "Menory allocation failed\n");
1103 		return -ENOMEM;
1104 	}
1105 
1106 	dev->base = devm_request_and_ioremap(&pdev->dev, mem);
1107 	if (!dev->base) {
1108 		dev_err(&pdev->dev, "I2C region already claimed\n");
1109 		return -ENOMEM;
1110 	}
1111 
1112 	match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev);
1113 	if (match) {
1114 		u32 freq = 100000; /* default to 100000 Hz */
1115 
1116 		pdata = match->data;
1117 		dev->flags = pdata->flags;
1118 
1119 		of_property_read_u32(node, "clock-frequency", &freq);
1120 		/* convert DT freq value in Hz into kHz for speed */
1121 		dev->speed = freq / 1000;
1122 	} else if (pdata != NULL) {
1123 		dev->speed = pdata->clkrate;
1124 		dev->flags = pdata->flags;
1125 		dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
1126 	}
1127 
1128 	dev->pins = devm_pinctrl_get_select_default(&pdev->dev);
1129 	if (IS_ERR(dev->pins)) {
1130 		if (PTR_ERR(dev->pins) == -EPROBE_DEFER)
1131 			return -EPROBE_DEFER;
1132 
1133 		dev_warn(&pdev->dev, "did not get pins for i2c error: %li\n",
1134 			 PTR_ERR(dev->pins));
1135 		dev->pins = NULL;
1136 	}
1137 
1138 	dev->dev = &pdev->dev;
1139 	dev->irq = irq;
1140 
1141 	spin_lock_init(&dev->lock);
1142 
1143 	platform_set_drvdata(pdev, dev);
1144 	init_completion(&dev->cmd_complete);
1145 
1146 	dev->reg_shift = (dev->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
1147 
1148 	pm_runtime_enable(dev->dev);
1149 	pm_runtime_set_autosuspend_delay(dev->dev, OMAP_I2C_PM_TIMEOUT);
1150 	pm_runtime_use_autosuspend(dev->dev);
1151 
1152 	r = pm_runtime_get_sync(dev->dev);
1153 	if (IS_ERR_VALUE(r))
1154 		goto err_free_mem;
1155 
1156 	/*
1157 	 * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.
1158 	 * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset.
1159 	 * Also since the omap_i2c_read_reg uses reg_map_ip_* a
1160 	 * raw_readw is done.
1161 	 */
1162 	rev = __raw_readw(dev->base + 0x04);
1163 
1164 	scheme = OMAP_I2C_SCHEME(rev);
1165 	switch (scheme) {
1166 	case OMAP_I2C_SCHEME_0:
1167 		dev->regs = (u8 *)reg_map_ip_v1;
1168 		dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG);
1169 		minor = OMAP_I2C_REV_SCHEME_0_MAJOR(dev->rev);
1170 		major = OMAP_I2C_REV_SCHEME_0_MAJOR(dev->rev);
1171 		break;
1172 	case OMAP_I2C_SCHEME_1:
1173 		/* FALLTHROUGH */
1174 	default:
1175 		dev->regs = (u8 *)reg_map_ip_v2;
1176 		rev = (rev << 16) |
1177 			omap_i2c_read_reg(dev, OMAP_I2C_IP_V2_REVNB_LO);
1178 		minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev);
1179 		major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev);
1180 		dev->rev = rev;
1181 	}
1182 
1183 	dev->errata = 0;
1184 
1185 	if (dev->rev >= OMAP_I2C_REV_ON_2430 &&
1186 			dev->rev < OMAP_I2C_REV_ON_4430_PLUS)
1187 		dev->errata |= I2C_OMAP_ERRATA_I207;
1188 
1189 	if (dev->rev <= OMAP_I2C_REV_ON_3430_3530)
1190 		dev->errata |= I2C_OMAP_ERRATA_I462;
1191 
1192 	if (!(dev->flags & OMAP_I2C_FLAG_NO_FIFO)) {
1193 		u16 s;
1194 
1195 		/* Set up the fifo size - Get total size */
1196 		s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
1197 		dev->fifo_size = 0x8 << s;
1198 
1199 		/*
1200 		 * Set up notification threshold as half the total available
1201 		 * size. This is to ensure that we can handle the status on int
1202 		 * call back latencies.
1203 		 */
1204 
1205 		dev->fifo_size = (dev->fifo_size / 2);
1206 
1207 		if (dev->rev < OMAP_I2C_REV_ON_3630)
1208 			dev->b_hw = 1; /* Enable hardware fixes */
1209 
1210 		/* calculate wakeup latency constraint for MPU */
1211 		if (dev->set_mpu_wkup_lat != NULL)
1212 			dev->latency = (1000000 * dev->fifo_size) /
1213 				       (1000 * dev->speed / 8);
1214 	}
1215 
1216 	/* reset ASAP, clearing any IRQs */
1217 	omap_i2c_init(dev);
1218 
1219 	if (dev->rev < OMAP_I2C_OMAP1_REV_2)
1220 		r = devm_request_irq(&pdev->dev, dev->irq, omap_i2c_omap1_isr,
1221 				IRQF_NO_SUSPEND, pdev->name, dev);
1222 	else
1223 		r = devm_request_threaded_irq(&pdev->dev, dev->irq,
1224 				omap_i2c_isr, omap_i2c_isr_thread,
1225 				IRQF_NO_SUSPEND | IRQF_ONESHOT,
1226 				pdev->name, dev);
1227 
1228 	if (r) {
1229 		dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
1230 		goto err_unuse_clocks;
1231 	}
1232 
1233 	adap = &dev->adapter;
1234 	i2c_set_adapdata(adap, dev);
1235 	adap->owner = THIS_MODULE;
1236 	adap->class = I2C_CLASS_HWMON;
1237 	strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
1238 	adap->algo = &omap_i2c_algo;
1239 	adap->dev.parent = &pdev->dev;
1240 	adap->dev.of_node = pdev->dev.of_node;
1241 
1242 	/* i2c device drivers may be active on return from add_adapter() */
1243 	adap->nr = pdev->id;
1244 	r = i2c_add_numbered_adapter(adap);
1245 	if (r) {
1246 		dev_err(dev->dev, "failure adding adapter\n");
1247 		goto err_unuse_clocks;
1248 	}
1249 
1250 	dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr,
1251 		 major, minor, dev->speed);
1252 
1253 	of_i2c_register_devices(adap);
1254 
1255 	pm_runtime_mark_last_busy(dev->dev);
1256 	pm_runtime_put_autosuspend(dev->dev);
1257 
1258 	return 0;
1259 
1260 err_unuse_clocks:
1261 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1262 	pm_runtime_put(dev->dev);
1263 	pm_runtime_disable(&pdev->dev);
1264 err_free_mem:
1265 	platform_set_drvdata(pdev, NULL);
1266 
1267 	return r;
1268 }
1269 
1270 static int __devexit omap_i2c_remove(struct platform_device *pdev)
1271 {
1272 	struct omap_i2c_dev	*dev = platform_get_drvdata(pdev);
1273 	int ret;
1274 
1275 	platform_set_drvdata(pdev, NULL);
1276 
1277 	i2c_del_adapter(&dev->adapter);
1278 	ret = pm_runtime_get_sync(&pdev->dev);
1279 	if (IS_ERR_VALUE(ret))
1280 		return ret;
1281 
1282 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1283 	pm_runtime_put(&pdev->dev);
1284 	pm_runtime_disable(&pdev->dev);
1285 	return 0;
1286 }
1287 
1288 #ifdef CONFIG_PM
1289 #ifdef CONFIG_PM_RUNTIME
1290 static int omap_i2c_runtime_suspend(struct device *dev)
1291 {
1292 	struct platform_device *pdev = to_platform_device(dev);
1293 	struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
1294 
1295 	_dev->iestate = omap_i2c_read_reg(_dev, OMAP_I2C_IE_REG);
1296 
1297 	omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, 0);
1298 
1299 	if (_dev->rev < OMAP_I2C_OMAP1_REV_2) {
1300 		omap_i2c_read_reg(_dev, OMAP_I2C_IV_REG); /* Read clears */
1301 	} else {
1302 		omap_i2c_write_reg(_dev, OMAP_I2C_STAT_REG, _dev->iestate);
1303 
1304 		/* Flush posted write */
1305 		omap_i2c_read_reg(_dev, OMAP_I2C_STAT_REG);
1306 	}
1307 
1308 	return 0;
1309 }
1310 
1311 static int omap_i2c_runtime_resume(struct device *dev)
1312 {
1313 	struct platform_device *pdev = to_platform_device(dev);
1314 	struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
1315 
1316 	if (!_dev->regs)
1317 		return 0;
1318 
1319 	__omap_i2c_init(_dev);
1320 
1321 	return 0;
1322 }
1323 #endif /* CONFIG_PM_RUNTIME */
1324 
1325 static struct dev_pm_ops omap_i2c_pm_ops = {
1326 	SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
1327 			   omap_i2c_runtime_resume, NULL)
1328 };
1329 #define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
1330 #else
1331 #define OMAP_I2C_PM_OPS NULL
1332 #endif /* CONFIG_PM */
1333 
1334 static struct platform_driver omap_i2c_driver = {
1335 	.probe		= omap_i2c_probe,
1336 	.remove		= __devexit_p(omap_i2c_remove),
1337 	.driver		= {
1338 		.name	= "omap_i2c",
1339 		.owner	= THIS_MODULE,
1340 		.pm	= OMAP_I2C_PM_OPS,
1341 		.of_match_table = of_match_ptr(omap_i2c_of_match),
1342 	},
1343 };
1344 
1345 /* I2C may be needed to bring up other drivers */
1346 static int __init
1347 omap_i2c_init_driver(void)
1348 {
1349 	return platform_driver_register(&omap_i2c_driver);
1350 }
1351 subsys_initcall(omap_i2c_init_driver);
1352 
1353 static void __exit omap_i2c_exit_driver(void)
1354 {
1355 	platform_driver_unregister(&omap_i2c_driver);
1356 }
1357 module_exit(omap_i2c_exit_driver);
1358 
1359 MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
1360 MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
1361 MODULE_LICENSE("GPL");
1362 MODULE_ALIAS("platform:omap_i2c");
1363