xref: /linux/drivers/i2c/busses/i2c-imx.c (revision b889fcf63cb62e7fdb7816565e28f44dbe4a76a5)
1 /*
2  *	Copyright (C) 2002 Motorola GSG-China
3  *
4  *	This program is free software; you can redistribute it and/or
5  *	modify it under the terms of the GNU General Public License
6  *	as published by the Free Software Foundation; either version 2
7  *	of the License, or (at your option) any later version.
8  *
9  *	This program is distributed in the hope that it will be useful,
10  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *	GNU General Public License for more details.
13  *
14  *	You should have received a copy of the GNU General Public License
15  *	along with this program; if not, write to the Free Software
16  *	Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
17  *	USA.
18  *
19  * Author:
20  *	Darius Augulis, Teltonika Inc.
21  *
22  * Desc.:
23  *	Implementation of I2C Adapter/Algorithm Driver
24  *	for I2C Bus integrated in Freescale i.MX/MXC processors
25  *
26  *	Derived from Motorola GSG China I2C example driver
27  *
28  *	Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
29  *	Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
30  *	Copyright (C) 2007 RightHand Technologies, Inc.
31  *	Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
32  *
33  */
34 
35 /** Includes *******************************************************************
36 *******************************************************************************/
37 
38 #include <linux/init.h>
39 #include <linux/kernel.h>
40 #include <linux/module.h>
41 #include <linux/errno.h>
42 #include <linux/err.h>
43 #include <linux/interrupt.h>
44 #include <linux/delay.h>
45 #include <linux/i2c.h>
46 #include <linux/io.h>
47 #include <linux/sched.h>
48 #include <linux/platform_device.h>
49 #include <linux/clk.h>
50 #include <linux/slab.h>
51 #include <linux/of.h>
52 #include <linux/of_device.h>
53 #include <linux/of_i2c.h>
54 #include <linux/pinctrl/consumer.h>
55 #include <linux/platform_data/i2c-imx.h>
56 
57 /** Defines ********************************************************************
58 *******************************************************************************/
59 
60 /* This will be the driver name the kernel reports */
61 #define DRIVER_NAME "imx-i2c"
62 
63 /* Default value */
64 #define IMX_I2C_BIT_RATE	100000	/* 100kHz */
65 
66 /* IMX I2C registers */
67 #define IMX_I2C_IADR	0x00	/* i2c slave address */
68 #define IMX_I2C_IFDR	0x04	/* i2c frequency divider */
69 #define IMX_I2C_I2CR	0x08	/* i2c control */
70 #define IMX_I2C_I2SR	0x0C	/* i2c status */
71 #define IMX_I2C_I2DR	0x10	/* i2c transfer data */
72 
73 /* Bits of IMX I2C registers */
74 #define I2SR_RXAK	0x01
75 #define I2SR_IIF	0x02
76 #define I2SR_SRW	0x04
77 #define I2SR_IAL	0x10
78 #define I2SR_IBB	0x20
79 #define I2SR_IAAS	0x40
80 #define I2SR_ICF	0x80
81 #define I2CR_RSTA	0x04
82 #define I2CR_TXAK	0x08
83 #define I2CR_MTX	0x10
84 #define I2CR_MSTA	0x20
85 #define I2CR_IIEN	0x40
86 #define I2CR_IEN	0x80
87 
88 /** Variables ******************************************************************
89 *******************************************************************************/
90 
91 /*
92  * sorted list of clock divider, register value pairs
93  * taken from table 26-5, p.26-9, Freescale i.MX
94  * Integrated Portable System Processor Reference Manual
95  * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
96  *
97  * Duplicated divider values removed from list
98  */
99 
100 static u16 __initdata i2c_clk_div[50][2] = {
101 	{ 22,	0x20 }, { 24,	0x21 }, { 26,	0x22 }, { 28,	0x23 },
102 	{ 30,	0x00 },	{ 32,	0x24 }, { 36,	0x25 }, { 40,	0x26 },
103 	{ 42,	0x03 }, { 44,	0x27 },	{ 48,	0x28 }, { 52,	0x05 },
104 	{ 56,	0x29 }, { 60,	0x06 }, { 64,	0x2A },	{ 72,	0x2B },
105 	{ 80,	0x2C }, { 88,	0x09 }, { 96,	0x2D }, { 104,	0x0A },
106 	{ 112,	0x2E }, { 128,	0x2F }, { 144,	0x0C }, { 160,	0x30 },
107 	{ 192,	0x31 },	{ 224,	0x32 }, { 240,	0x0F }, { 256,	0x33 },
108 	{ 288,	0x10 }, { 320,	0x34 },	{ 384,	0x35 }, { 448,	0x36 },
109 	{ 480,	0x13 }, { 512,	0x37 }, { 576,	0x14 },	{ 640,	0x38 },
110 	{ 768,	0x39 }, { 896,	0x3A }, { 960,	0x17 }, { 1024,	0x3B },
111 	{ 1152,	0x18 }, { 1280,	0x3C }, { 1536,	0x3D }, { 1792,	0x3E },
112 	{ 1920,	0x1B },	{ 2048,	0x3F }, { 2304,	0x1C }, { 2560,	0x1D },
113 	{ 3072,	0x1E }, { 3840,	0x1F }
114 };
115 
116 enum imx_i2c_type {
117 	IMX1_I2C,
118 	IMX21_I2C,
119 };
120 
121 struct imx_i2c_struct {
122 	struct i2c_adapter	adapter;
123 	struct clk		*clk;
124 	void __iomem		*base;
125 	wait_queue_head_t	queue;
126 	unsigned long		i2csr;
127 	unsigned int 		disable_delay;
128 	int			stopped;
129 	unsigned int		ifdr; /* IMX_I2C_IFDR */
130 	enum imx_i2c_type	devtype;
131 };
132 
133 static struct platform_device_id imx_i2c_devtype[] = {
134 	{
135 		.name = "imx1-i2c",
136 		.driver_data = IMX1_I2C,
137 	}, {
138 		.name = "imx21-i2c",
139 		.driver_data = IMX21_I2C,
140 	}, {
141 		/* sentinel */
142 	}
143 };
144 MODULE_DEVICE_TABLE(platform, imx_i2c_devtype);
145 
146 static const struct of_device_id i2c_imx_dt_ids[] = {
147 	{ .compatible = "fsl,imx1-i2c", .data = &imx_i2c_devtype[IMX1_I2C], },
148 	{ .compatible = "fsl,imx21-i2c", .data = &imx_i2c_devtype[IMX21_I2C], },
149 	{ /* sentinel */ }
150 };
151 
152 static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx)
153 {
154 	return i2c_imx->devtype == IMX1_I2C;
155 }
156 
157 /** Functions for IMX I2C adapter driver ***************************************
158 *******************************************************************************/
159 
160 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
161 {
162 	unsigned long orig_jiffies = jiffies;
163 	unsigned int temp;
164 
165 	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
166 
167 	while (1) {
168 		temp = readb(i2c_imx->base + IMX_I2C_I2SR);
169 		if (for_busy && (temp & I2SR_IBB))
170 			break;
171 		if (!for_busy && !(temp & I2SR_IBB))
172 			break;
173 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
174 			dev_dbg(&i2c_imx->adapter.dev,
175 				"<%s> I2C bus is busy\n", __func__);
176 			return -ETIMEDOUT;
177 		}
178 		schedule();
179 	}
180 
181 	return 0;
182 }
183 
184 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
185 {
186 	wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
187 
188 	if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
189 		dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
190 		return -ETIMEDOUT;
191 	}
192 	dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
193 	i2c_imx->i2csr = 0;
194 	return 0;
195 }
196 
197 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
198 {
199 	if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
200 		dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
201 		return -EIO;  /* No ACK */
202 	}
203 
204 	dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
205 	return 0;
206 }
207 
208 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
209 {
210 	unsigned int temp = 0;
211 	int result;
212 
213 	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
214 
215 	clk_prepare_enable(i2c_imx->clk);
216 	writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
217 	/* Enable I2C controller */
218 	writeb(0, i2c_imx->base + IMX_I2C_I2SR);
219 	writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
220 
221 	/* Wait controller to be stable */
222 	udelay(50);
223 
224 	/* Start I2C transaction */
225 	temp = readb(i2c_imx->base + IMX_I2C_I2CR);
226 	temp |= I2CR_MSTA;
227 	writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
228 	result = i2c_imx_bus_busy(i2c_imx, 1);
229 	if (result)
230 		return result;
231 	i2c_imx->stopped = 0;
232 
233 	temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
234 	writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
235 	return result;
236 }
237 
238 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
239 {
240 	unsigned int temp = 0;
241 
242 	if (!i2c_imx->stopped) {
243 		/* Stop I2C transaction */
244 		dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
245 		temp = readb(i2c_imx->base + IMX_I2C_I2CR);
246 		temp &= ~(I2CR_MSTA | I2CR_MTX);
247 		writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
248 	}
249 	if (is_imx1_i2c(i2c_imx)) {
250 		/*
251 		 * This delay caused by an i.MXL hardware bug.
252 		 * If no (or too short) delay, no "STOP" bit will be generated.
253 		 */
254 		udelay(i2c_imx->disable_delay);
255 	}
256 
257 	if (!i2c_imx->stopped) {
258 		i2c_imx_bus_busy(i2c_imx, 0);
259 		i2c_imx->stopped = 1;
260 	}
261 
262 	/* Disable I2C controller */
263 	writeb(0, i2c_imx->base + IMX_I2C_I2CR);
264 	clk_disable_unprepare(i2c_imx->clk);
265 }
266 
267 static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
268 							unsigned int rate)
269 {
270 	unsigned int i2c_clk_rate;
271 	unsigned int div;
272 	int i;
273 
274 	/* Divider value calculation */
275 	i2c_clk_rate = clk_get_rate(i2c_imx->clk);
276 	div = (i2c_clk_rate + rate - 1) / rate;
277 	if (div < i2c_clk_div[0][0])
278 		i = 0;
279 	else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
280 		i = ARRAY_SIZE(i2c_clk_div) - 1;
281 	else
282 		for (i = 0; i2c_clk_div[i][0] < div; i++);
283 
284 	/* Store divider value */
285 	i2c_imx->ifdr = i2c_clk_div[i][1];
286 
287 	/*
288 	 * There dummy delay is calculated.
289 	 * It should be about one I2C clock period long.
290 	 * This delay is used in I2C bus disable function
291 	 * to fix chip hardware bug.
292 	 */
293 	i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
294 		+ (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
295 
296 	/* dev_dbg() can't be used, because adapter is not yet registered */
297 #ifdef CONFIG_I2C_DEBUG_BUS
298 	dev_dbg(&i2c_imx->adapter.dev, "<%s> I2C_CLK=%d, REQ DIV=%d\n",
299 		__func__, i2c_clk_rate, div);
300 	dev_dbg(&i2c_imx->adapter.dev, "<%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
301 		__func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
302 #endif
303 }
304 
305 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
306 {
307 	struct imx_i2c_struct *i2c_imx = dev_id;
308 	unsigned int temp;
309 
310 	temp = readb(i2c_imx->base + IMX_I2C_I2SR);
311 	if (temp & I2SR_IIF) {
312 		/* save status register */
313 		i2c_imx->i2csr = temp;
314 		temp &= ~I2SR_IIF;
315 		writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
316 		wake_up(&i2c_imx->queue);
317 		return IRQ_HANDLED;
318 	}
319 
320 	return IRQ_NONE;
321 }
322 
323 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
324 {
325 	int i, result;
326 
327 	dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
328 		__func__, msgs->addr << 1);
329 
330 	/* write slave address */
331 	writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
332 	result = i2c_imx_trx_complete(i2c_imx);
333 	if (result)
334 		return result;
335 	result = i2c_imx_acked(i2c_imx);
336 	if (result)
337 		return result;
338 	dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
339 
340 	/* write data */
341 	for (i = 0; i < msgs->len; i++) {
342 		dev_dbg(&i2c_imx->adapter.dev,
343 			"<%s> write byte: B%d=0x%X\n",
344 			__func__, i, msgs->buf[i]);
345 		writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
346 		result = i2c_imx_trx_complete(i2c_imx);
347 		if (result)
348 			return result;
349 		result = i2c_imx_acked(i2c_imx);
350 		if (result)
351 			return result;
352 	}
353 	return 0;
354 }
355 
356 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
357 {
358 	int i, result;
359 	unsigned int temp;
360 
361 	dev_dbg(&i2c_imx->adapter.dev,
362 		"<%s> write slave address: addr=0x%x\n",
363 		__func__, (msgs->addr << 1) | 0x01);
364 
365 	/* write slave address */
366 	writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
367 	result = i2c_imx_trx_complete(i2c_imx);
368 	if (result)
369 		return result;
370 	result = i2c_imx_acked(i2c_imx);
371 	if (result)
372 		return result;
373 
374 	dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
375 
376 	/* setup bus to read data */
377 	temp = readb(i2c_imx->base + IMX_I2C_I2CR);
378 	temp &= ~I2CR_MTX;
379 	if (msgs->len - 1)
380 		temp &= ~I2CR_TXAK;
381 	writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
382 	readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
383 
384 	dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
385 
386 	/* read data */
387 	for (i = 0; i < msgs->len; i++) {
388 		result = i2c_imx_trx_complete(i2c_imx);
389 		if (result)
390 			return result;
391 		if (i == (msgs->len - 1)) {
392 			/* It must generate STOP before read I2DR to prevent
393 			   controller from generating another clock cycle */
394 			dev_dbg(&i2c_imx->adapter.dev,
395 				"<%s> clear MSTA\n", __func__);
396 			temp = readb(i2c_imx->base + IMX_I2C_I2CR);
397 			temp &= ~(I2CR_MSTA | I2CR_MTX);
398 			writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
399 			i2c_imx_bus_busy(i2c_imx, 0);
400 			i2c_imx->stopped = 1;
401 		} else if (i == (msgs->len - 2)) {
402 			dev_dbg(&i2c_imx->adapter.dev,
403 				"<%s> set TXAK\n", __func__);
404 			temp = readb(i2c_imx->base + IMX_I2C_I2CR);
405 			temp |= I2CR_TXAK;
406 			writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
407 		}
408 		msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
409 		dev_dbg(&i2c_imx->adapter.dev,
410 			"<%s> read byte: B%d=0x%X\n",
411 			__func__, i, msgs->buf[i]);
412 	}
413 	return 0;
414 }
415 
416 static int i2c_imx_xfer(struct i2c_adapter *adapter,
417 						struct i2c_msg *msgs, int num)
418 {
419 	unsigned int i, temp;
420 	int result;
421 	struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
422 
423 	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
424 
425 	/* Start I2C transfer */
426 	result = i2c_imx_start(i2c_imx);
427 	if (result)
428 		goto fail0;
429 
430 	/* read/write data */
431 	for (i = 0; i < num; i++) {
432 		if (i) {
433 			dev_dbg(&i2c_imx->adapter.dev,
434 				"<%s> repeated start\n", __func__);
435 			temp = readb(i2c_imx->base + IMX_I2C_I2CR);
436 			temp |= I2CR_RSTA;
437 			writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
438 			result =  i2c_imx_bus_busy(i2c_imx, 1);
439 			if (result)
440 				goto fail0;
441 		}
442 		dev_dbg(&i2c_imx->adapter.dev,
443 			"<%s> transfer message: %d\n", __func__, i);
444 		/* write/read data */
445 #ifdef CONFIG_I2C_DEBUG_BUS
446 		temp = readb(i2c_imx->base + IMX_I2C_I2CR);
447 		dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
448 			"MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
449 			(temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
450 			(temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
451 			(temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
452 		temp = readb(i2c_imx->base + IMX_I2C_I2SR);
453 		dev_dbg(&i2c_imx->adapter.dev,
454 			"<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
455 			"IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
456 			(temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
457 			(temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
458 			(temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
459 			(temp & I2SR_RXAK ? 1 : 0));
460 #endif
461 		if (msgs[i].flags & I2C_M_RD)
462 			result = i2c_imx_read(i2c_imx, &msgs[i]);
463 		else
464 			result = i2c_imx_write(i2c_imx, &msgs[i]);
465 		if (result)
466 			goto fail0;
467 	}
468 
469 fail0:
470 	/* Stop I2C transfer */
471 	i2c_imx_stop(i2c_imx);
472 
473 	dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
474 		(result < 0) ? "error" : "success msg",
475 			(result < 0) ? result : num);
476 	return (result < 0) ? result : num;
477 }
478 
479 static u32 i2c_imx_func(struct i2c_adapter *adapter)
480 {
481 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
482 }
483 
484 static struct i2c_algorithm i2c_imx_algo = {
485 	.master_xfer	= i2c_imx_xfer,
486 	.functionality	= i2c_imx_func,
487 };
488 
489 static int __init i2c_imx_probe(struct platform_device *pdev)
490 {
491 	const struct of_device_id *of_id = of_match_device(i2c_imx_dt_ids,
492 							   &pdev->dev);
493 	struct imx_i2c_struct *i2c_imx;
494 	struct resource *res;
495 	struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
496 	struct pinctrl *pinctrl;
497 	void __iomem *base;
498 	int irq, ret;
499 	u32 bitrate;
500 
501 	dev_dbg(&pdev->dev, "<%s>\n", __func__);
502 
503 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
504 	if (!res) {
505 		dev_err(&pdev->dev, "can't get device resources\n");
506 		return -ENOENT;
507 	}
508 	irq = platform_get_irq(pdev, 0);
509 	if (irq < 0) {
510 		dev_err(&pdev->dev, "can't get irq number\n");
511 		return -ENOENT;
512 	}
513 
514 	base = devm_request_and_ioremap(&pdev->dev, res);
515 	if (!base)
516 		return -EBUSY;
517 
518 	i2c_imx = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_struct),
519 				GFP_KERNEL);
520 	if (!i2c_imx) {
521 		dev_err(&pdev->dev, "can't allocate interface\n");
522 		return -ENOMEM;
523 	}
524 
525 	if (of_id)
526 		pdev->id_entry = of_id->data;
527 	i2c_imx->devtype = pdev->id_entry->driver_data;
528 
529 	/* Setup i2c_imx driver structure */
530 	strlcpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
531 	i2c_imx->adapter.owner		= THIS_MODULE;
532 	i2c_imx->adapter.algo		= &i2c_imx_algo;
533 	i2c_imx->adapter.dev.parent	= &pdev->dev;
534 	i2c_imx->adapter.nr 		= pdev->id;
535 	i2c_imx->adapter.dev.of_node	= pdev->dev.of_node;
536 	i2c_imx->base			= base;
537 
538 	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
539 	if (IS_ERR(pinctrl)) {
540 		dev_err(&pdev->dev, "can't get/select pinctrl\n");
541 		return PTR_ERR(pinctrl);
542 	}
543 
544 	/* Get I2C clock */
545 	i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
546 	if (IS_ERR(i2c_imx->clk)) {
547 		dev_err(&pdev->dev, "can't get I2C clock\n");
548 		return PTR_ERR(i2c_imx->clk);
549 	}
550 
551 	/* Request IRQ */
552 	ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, 0,
553 				pdev->name, i2c_imx);
554 	if (ret) {
555 		dev_err(&pdev->dev, "can't claim irq %d\n", irq);
556 		return ret;
557 	}
558 
559 	/* Init queue */
560 	init_waitqueue_head(&i2c_imx->queue);
561 
562 	/* Set up adapter data */
563 	i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
564 
565 	/* Set up clock divider */
566 	bitrate = IMX_I2C_BIT_RATE;
567 	ret = of_property_read_u32(pdev->dev.of_node,
568 				   "clock-frequency", &bitrate);
569 	if (ret < 0 && pdata && pdata->bitrate)
570 		bitrate = pdata->bitrate;
571 	i2c_imx_set_clk(i2c_imx, bitrate);
572 
573 	/* Set up chip registers to defaults */
574 	writeb(0, i2c_imx->base + IMX_I2C_I2CR);
575 	writeb(0, i2c_imx->base + IMX_I2C_I2SR);
576 
577 	/* Add I2C adapter */
578 	ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
579 	if (ret < 0) {
580 		dev_err(&pdev->dev, "registration failed\n");
581 		return ret;
582 	}
583 
584 	of_i2c_register_devices(&i2c_imx->adapter);
585 
586 	/* Set up platform driver data */
587 	platform_set_drvdata(pdev, i2c_imx);
588 
589 	dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
590 	dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
591 		res->start, res->end);
592 	dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x\n",
593 		resource_size(res), res->start);
594 	dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
595 		i2c_imx->adapter.name);
596 	dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
597 
598 	return 0;   /* Return OK */
599 }
600 
601 static int __exit i2c_imx_remove(struct platform_device *pdev)
602 {
603 	struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
604 
605 	/* remove adapter */
606 	dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
607 	i2c_del_adapter(&i2c_imx->adapter);
608 	platform_set_drvdata(pdev, NULL);
609 
610 	/* setup chip registers to defaults */
611 	writeb(0, i2c_imx->base + IMX_I2C_IADR);
612 	writeb(0, i2c_imx->base + IMX_I2C_IFDR);
613 	writeb(0, i2c_imx->base + IMX_I2C_I2CR);
614 	writeb(0, i2c_imx->base + IMX_I2C_I2SR);
615 
616 	return 0;
617 }
618 
619 static struct platform_driver i2c_imx_driver = {
620 	.remove		= __exit_p(i2c_imx_remove),
621 	.driver	= {
622 		.name	= DRIVER_NAME,
623 		.owner	= THIS_MODULE,
624 		.of_match_table = i2c_imx_dt_ids,
625 	},
626 	.id_table	= imx_i2c_devtype,
627 };
628 
629 static int __init i2c_adap_imx_init(void)
630 {
631 	return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
632 }
633 subsys_initcall(i2c_adap_imx_init);
634 
635 static void __exit i2c_adap_imx_exit(void)
636 {
637 	platform_driver_unregister(&i2c_imx_driver);
638 }
639 module_exit(i2c_adap_imx_exit);
640 
641 MODULE_LICENSE("GPL");
642 MODULE_AUTHOR("Darius Augulis");
643 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
644 MODULE_ALIAS("platform:" DRIVER_NAME);
645