1/*
2 * TI OMAP I2C master mode driver
3 *
4 * Copyright (C) 2003 MontaVista Software, Inc.
5 * Copyright (C) 2004 Texas Instruments.
6 *
7 * Updated to work with multiple I2C interfaces on 24xx by
8 * Tony Lindgren <tony@atomide.com> and Imre Deak <imre.deak@nokia.com>
9 * Copyright (C) 2005 Nokia Corporation
10 *
11 * Cleaned up by Juha Yrj�l� <juha.yrjola@nokia.com>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
27
28#include <linux/module.h>
29#include <linux/delay.h>
30#include <linux/i2c.h>
31#include <linux/err.h>
32#include <linux/interrupt.h>
33#include <linux/completion.h>
34#include <linux/platform_device.h>
35#include <linux/clk.h>
36
37#include <asm/io.h>
38
39/* timeout waiting for the controller to respond */
40#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
41
42#define OMAP_I2C_REV_REG		0x00
43#define OMAP_I2C_IE_REG			0x04
44#define OMAP_I2C_STAT_REG		0x08
45#define OMAP_I2C_IV_REG			0x0c
46#define OMAP_I2C_SYSS_REG		0x10
47#define OMAP_I2C_BUF_REG		0x14
48#define OMAP_I2C_CNT_REG		0x18
49#define OMAP_I2C_DATA_REG		0x1c
50#define OMAP_I2C_SYSC_REG		0x20
51#define OMAP_I2C_CON_REG		0x24
52#define OMAP_I2C_OA_REG			0x28
53#define OMAP_I2C_SA_REG			0x2c
54#define OMAP_I2C_PSC_REG		0x30
55#define OMAP_I2C_SCLL_REG		0x34
56#define OMAP_I2C_SCLH_REG		0x38
57#define OMAP_I2C_SYSTEST_REG		0x3c
58
59/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
60#define OMAP_I2C_IE_XRDY	(1 << 4)	/* TX data ready int enable */
61#define OMAP_I2C_IE_RRDY	(1 << 3)	/* RX data ready int enable */
62#define OMAP_I2C_IE_ARDY	(1 << 2)	/* Access ready int enable */
63#define OMAP_I2C_IE_NACK	(1 << 1)	/* No ack interrupt enable */
64#define OMAP_I2C_IE_AL		(1 << 0)	/* Arbitration lost int ena */
65
66/* I2C Status Register (OMAP_I2C_STAT): */
67#define OMAP_I2C_STAT_SBD	(1 << 15)	/* Single byte data */
68#define OMAP_I2C_STAT_BB	(1 << 12)	/* Bus busy */
69#define OMAP_I2C_STAT_ROVR	(1 << 11)	/* Receive overrun */
70#define OMAP_I2C_STAT_XUDF	(1 << 10)	/* Transmit underflow */
71#define OMAP_I2C_STAT_AAS	(1 << 9)	/* Address as slave */
72#define OMAP_I2C_STAT_AD0	(1 << 8)	/* Address zero */
73#define OMAP_I2C_STAT_XRDY	(1 << 4)	/* Transmit data ready */
74#define OMAP_I2C_STAT_RRDY	(1 << 3)	/* Receive data ready */
75#define OMAP_I2C_STAT_ARDY	(1 << 2)	/* Register access ready */
76#define OMAP_I2C_STAT_NACK	(1 << 1)	/* No ack interrupt enable */
77#define OMAP_I2C_STAT_AL	(1 << 0)	/* Arbitration lost int ena */
78
79/* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
80#define OMAP_I2C_BUF_RDMA_EN	(1 << 15)	/* RX DMA channel enable */
81#define OMAP_I2C_BUF_XDMA_EN	(1 << 7)	/* TX DMA channel enable */
82
83/* I2C Configuration Register (OMAP_I2C_CON): */
84#define OMAP_I2C_CON_EN		(1 << 15)	/* I2C module enable */
85#define OMAP_I2C_CON_BE		(1 << 14)	/* Big endian mode */
86#define OMAP_I2C_CON_STB	(1 << 11)	/* Start byte mode (master) */
87#define OMAP_I2C_CON_MST	(1 << 10)	/* Master/slave mode */
88#define OMAP_I2C_CON_TRX	(1 << 9)	/* TX/RX mode (master only) */
89#define OMAP_I2C_CON_XA		(1 << 8)	/* Expand address */
90#define OMAP_I2C_CON_RM		(1 << 2)	/* Repeat mode (master only) */
91#define OMAP_I2C_CON_STP	(1 << 1)	/* Stop cond (master only) */
92#define OMAP_I2C_CON_STT	(1 << 0)	/* Start condition (master) */
93
94/* I2C System Test Register (OMAP_I2C_SYSTEST): */
95#ifdef DEBUG
96#define OMAP_I2C_SYSTEST_ST_EN		(1 << 15)	/* System test enable */
97#define OMAP_I2C_SYSTEST_FREE		(1 << 14)	/* Free running mode */
98#define OMAP_I2C_SYSTEST_TMODE_MASK	(3 << 12)	/* Test mode select */
99#define OMAP_I2C_SYSTEST_TMODE_SHIFT	(12)		/* Test mode select */
100#define OMAP_I2C_SYSTEST_SCL_I		(1 << 3)	/* SCL line sense in */
101#define OMAP_I2C_SYSTEST_SCL_O		(1 << 2)	/* SCL line drive out */
102#define OMAP_I2C_SYSTEST_SDA_I		(1 << 1)	/* SDA line sense in */
103#define OMAP_I2C_SYSTEST_SDA_O		(1 << 0)	/* SDA line drive out */
104#endif
105
106/* I2C System Status register (OMAP_I2C_SYSS): */
107#define OMAP_I2C_SYSS_RDONE		(1 << 0)	/* Reset Done */
108
109/* I2C System Configuration Register (OMAP_I2C_SYSC): */
110#define OMAP_I2C_SYSC_SRST		(1 << 1)	/* Soft Reset */
111
112/* REVISIT: Use platform_data instead of module parameters */
113/* Fast Mode = 400 kHz, Standard = 100 kHz */
114static int clock = 100; /* Default: 100 kHz */
115module_param(clock, int, 0);
116MODULE_PARM_DESC(clock, "Set I2C clock in kHz: 400=fast mode (default == 100)");
117
118struct omap_i2c_dev {
119	struct device		*dev;
120	void __iomem		*base;		/* virtual */
121	int			irq;
122	struct clk		*iclk;		/* Interface clock */
123	struct clk		*fclk;		/* Functional clock */
124	struct completion	cmd_complete;
125	struct resource		*ioarea;
126	u16			cmd_err;
127	u8			*buf;
128	size_t			buf_len;
129	struct i2c_adapter	adapter;
130	unsigned		rev1:1;
131};
132
133static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
134				      int reg, u16 val)
135{
136	__raw_writew(val, i2c_dev->base + reg);
137}
138
139static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
140{
141	return __raw_readw(i2c_dev->base + reg);
142}
143
144static int omap_i2c_get_clocks(struct omap_i2c_dev *dev)
145{
146	if (cpu_is_omap16xx() || cpu_is_omap24xx()) {
147		dev->iclk = clk_get(dev->dev, "i2c_ick");
148		if (IS_ERR(dev->iclk)) {
149			dev->iclk = NULL;
150			return -ENODEV;
151		}
152	}
153
154	dev->fclk = clk_get(dev->dev, "i2c_fck");
155	if (IS_ERR(dev->fclk)) {
156		if (dev->iclk != NULL) {
157			clk_put(dev->iclk);
158			dev->iclk = NULL;
159		}
160		dev->fclk = NULL;
161		return -ENODEV;
162	}
163
164	return 0;
165}
166
167static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
168{
169	clk_put(dev->fclk);
170	dev->fclk = NULL;
171	if (dev->iclk != NULL) {
172		clk_put(dev->iclk);
173		dev->iclk = NULL;
174	}
175}
176
177static void omap_i2c_enable_clocks(struct omap_i2c_dev *dev)
178{
179	if (dev->iclk != NULL)
180		clk_enable(dev->iclk);
181	clk_enable(dev->fclk);
182}
183
184static void omap_i2c_disable_clocks(struct omap_i2c_dev *dev)
185{
186	if (dev->iclk != NULL)
187		clk_disable(dev->iclk);
188	clk_disable(dev->fclk);
189}
190
191static int omap_i2c_init(struct omap_i2c_dev *dev)
192{
193	u16 psc = 0;
194	unsigned long fclk_rate = 12000000;
195	unsigned long timeout;
196
197	if (!dev->rev1) {
198		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, OMAP_I2C_SYSC_SRST);
199		/* For some reason we need to set the EN bit before the
200		 * reset done bit gets set. */
201		timeout = jiffies + OMAP_I2C_TIMEOUT;
202		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
203		while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
204			 OMAP_I2C_SYSS_RDONE)) {
205			if (time_after(jiffies, timeout)) {
206				dev_warn(dev->dev, "timeout waiting"
207						"for controller reset\n");
208				return -ETIMEDOUT;
209			}
210			msleep(1);
211		}
212	}
213	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
214
215	if (cpu_class_is_omap1()) {
216		struct clk *armxor_ck;
217
218		armxor_ck = clk_get(NULL, "armxor_ck");
219		if (IS_ERR(armxor_ck))
220			dev_warn(dev->dev, "Could not get armxor_ck\n");
221		else {
222			fclk_rate = clk_get_rate(armxor_ck);
223			clk_put(armxor_ck);
224		}
225		/* TRM for 5912 says the I2C clock must be prescaled to be
226		 * between 7 - 12 MHz. The XOR input clock is typically
227		 * 12, 13 or 19.2 MHz. So we should have code that produces:
228		 *
229		 * XOR MHz	Divider		Prescaler
230		 * 12		1		0
231		 * 13		2		1
232		 * 19.2		2		1
233		 */
234		if (fclk_rate > 12000000)
235			psc = fclk_rate / 12000000;
236	}
237
238	/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
239	omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
240
241	/* Program desired operating rate */
242	fclk_rate /= (psc + 1) * 1000;
243	if (psc > 2)
244		psc = 2;
245
246	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG,
247			   fclk_rate / (clock * 2) - 7 + psc);
248	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG,
249			   fclk_rate / (clock * 2) - 7 + psc);
250
251	/* Take the I2C module out of reset: */
252	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
253
254	/* Enable interrupts */
255	omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
256			   (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
257			    OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
258			    OMAP_I2C_IE_AL));
259	return 0;
260}
261
262/*
263 * Waiting on Bus Busy
264 */
265static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
266{
267	unsigned long timeout;
268
269	timeout = jiffies + OMAP_I2C_TIMEOUT;
270	while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
271		if (time_after(jiffies, timeout)) {
272			dev_warn(dev->dev, "timeout waiting for bus ready\n");
273			return -ETIMEDOUT;
274		}
275		msleep(1);
276	}
277
278	return 0;
279}
280
281/*
282 * Low level master read/write transaction.
283 */
284static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
285			     struct i2c_msg *msg, int stop)
286{
287	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
288	int r;
289	u16 w;
290
291	dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
292		msg->addr, msg->len, msg->flags, stop);
293
294	if (msg->len == 0)
295		return -EINVAL;
296
297	omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
298
299	/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
300	dev->buf = msg->buf;
301	dev->buf_len = msg->len;
302
303	omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
304
305	init_completion(&dev->cmd_complete);
306	dev->cmd_err = 0;
307
308	w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
309	if (msg->flags & I2C_M_TEN)
310		w |= OMAP_I2C_CON_XA;
311	if (!(msg->flags & I2C_M_RD))
312		w |= OMAP_I2C_CON_TRX;
313	if (stop)
314		w |= OMAP_I2C_CON_STP;
315	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
316
317	r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
318						      OMAP_I2C_TIMEOUT);
319	dev->buf_len = 0;
320	if (r < 0)
321		return r;
322	if (r == 0) {
323		dev_err(dev->dev, "controller timed out\n");
324		omap_i2c_init(dev);
325		return -ETIMEDOUT;
326	}
327
328	if (likely(!dev->cmd_err))
329		return 0;
330
331	/* We have an error */
332	if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
333			    OMAP_I2C_STAT_XUDF)) {
334		omap_i2c_init(dev);
335		return -EIO;
336	}
337
338	if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
339		if (msg->flags & I2C_M_IGNORE_NAK)
340			return 0;
341		if (stop) {
342			w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
343			w |= OMAP_I2C_CON_STP;
344			omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
345		}
346		return -EREMOTEIO;
347	}
348	return -EIO;
349}
350
351
352/*
353 * Prepare controller for a transaction and call omap_i2c_xfer_msg
354 * to do the work during IRQ processing.
355 */
356static int
357omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
358{
359	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
360	int i;
361	int r;
362
363	omap_i2c_enable_clocks(dev);
364
365	/* REVISIT: initialize and use adap->retries. This is an optional
366	 * feature */
367	if ((r = omap_i2c_wait_for_bb(dev)) < 0)
368		goto out;
369
370	for (i = 0; i < num; i++) {
371		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
372		if (r != 0)
373			break;
374	}
375
376	if (r == 0)
377		r = num;
378out:
379	omap_i2c_disable_clocks(dev);
380	return r;
381}
382
383static u32
384omap_i2c_func(struct i2c_adapter *adap)
385{
386	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
387}
388
389static inline void
390omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
391{
392	dev->cmd_err |= err;
393	complete(&dev->cmd_complete);
394}
395
396static inline void
397omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
398{
399	omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
400}
401
402static irqreturn_t
403omap_i2c_rev1_isr(int this_irq, void *dev_id)
404{
405	struct omap_i2c_dev *dev = dev_id;
406	u16 iv, w;
407
408	iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
409	switch (iv) {
410	case 0x00:	/* None */
411		break;
412	case 0x01:	/* Arbitration lost */
413		dev_err(dev->dev, "Arbitration lost\n");
414		omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
415		break;
416	case 0x02:	/* No acknowledgement */
417		omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
418		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
419		break;
420	case 0x03:	/* Register access ready */
421		omap_i2c_complete_cmd(dev, 0);
422		break;
423	case 0x04:	/* Receive data ready */
424		if (dev->buf_len) {
425			w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
426			*dev->buf++ = w;
427			dev->buf_len--;
428			if (dev->buf_len) {
429				*dev->buf++ = w >> 8;
430				dev->buf_len--;
431			}
432		} else
433			dev_err(dev->dev, "RRDY IRQ while no data requested\n");
434		break;
435	case 0x05:	/* Transmit data ready */
436		if (dev->buf_len) {
437			w = *dev->buf++;
438			dev->buf_len--;
439			if (dev->buf_len) {
440				w |= *dev->buf++ << 8;
441				dev->buf_len--;
442			}
443			omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
444		} else
445			dev_err(dev->dev, "XRDY IRQ while no data to send\n");
446		break;
447	default:
448		return IRQ_NONE;
449	}
450
451	return IRQ_HANDLED;
452}
453
454static irqreturn_t
455omap_i2c_isr(int this_irq, void *dev_id)
456{
457	struct omap_i2c_dev *dev = dev_id;
458	u16 bits;
459	u16 stat, w;
460	int count = 0;
461
462	bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
463	while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
464		dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
465		if (count++ == 100) {
466			dev_warn(dev->dev, "Too much work in one IRQ\n");
467			break;
468		}
469
470		omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
471
472		if (stat & OMAP_I2C_STAT_ARDY) {
473			omap_i2c_complete_cmd(dev, 0);
474			continue;
475		}
476		if (stat & OMAP_I2C_STAT_RRDY) {
477			w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
478			if (dev->buf_len) {
479				*dev->buf++ = w;
480				dev->buf_len--;
481				if (dev->buf_len) {
482					*dev->buf++ = w >> 8;
483					dev->buf_len--;
484				}
485			} else
486				dev_err(dev->dev, "RRDY IRQ while no data"
487						"requested\n");
488			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
489			continue;
490		}
491		if (stat & OMAP_I2C_STAT_XRDY) {
492			w = 0;
493			if (dev->buf_len) {
494				w = *dev->buf++;
495				dev->buf_len--;
496				if (dev->buf_len) {
497					w |= *dev->buf++ << 8;
498					dev->buf_len--;
499				}
500			} else
501				dev_err(dev->dev, "XRDY IRQ while no"
502					"data to send\n");
503			omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
504			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
505			continue;
506		}
507		if (stat & OMAP_I2C_STAT_ROVR) {
508			dev_err(dev->dev, "Receive overrun\n");
509			dev->cmd_err |= OMAP_I2C_STAT_ROVR;
510		}
511		if (stat & OMAP_I2C_STAT_XUDF) {
512			dev_err(dev->dev, "Transmit overflow\n");
513			dev->cmd_err |= OMAP_I2C_STAT_XUDF;
514		}
515		if (stat & OMAP_I2C_STAT_NACK) {
516			omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
517			omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
518					   OMAP_I2C_CON_STP);
519		}
520		if (stat & OMAP_I2C_STAT_AL) {
521			dev_err(dev->dev, "Arbitration lost\n");
522			omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
523		}
524	}
525
526	return count ? IRQ_HANDLED : IRQ_NONE;
527}
528
529static const struct i2c_algorithm omap_i2c_algo = {
530	.master_xfer	= omap_i2c_xfer,
531	.functionality	= omap_i2c_func,
532};
533
534static int
535omap_i2c_probe(struct platform_device *pdev)
536{
537	struct omap_i2c_dev	*dev;
538	struct i2c_adapter	*adap;
539	struct resource		*mem, *irq, *ioarea;
540	int r;
541
542	/* NOTE: driver uses the static register mapping */
543	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
544	if (!mem) {
545		dev_err(&pdev->dev, "no mem resource?\n");
546		return -ENODEV;
547	}
548	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
549	if (!irq) {
550		dev_err(&pdev->dev, "no irq resource?\n");
551		return -ENODEV;
552	}
553
554	ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
555			pdev->name);
556	if (!ioarea) {
557		dev_err(&pdev->dev, "I2C region already claimed\n");
558		return -EBUSY;
559	}
560
561	if (clock > 200)
562		clock = 400;	/* Fast mode */
563	else
564		clock = 100;	/* Standard mode */
565
566	dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
567	if (!dev) {
568		r = -ENOMEM;
569		goto err_release_region;
570	}
571
572	dev->dev = &pdev->dev;
573	dev->irq = irq->start;
574	dev->base = (void __iomem *) IO_ADDRESS(mem->start);
575	platform_set_drvdata(pdev, dev);
576
577	if ((r = omap_i2c_get_clocks(dev)) != 0)
578		goto err_free_mem;
579
580	omap_i2c_enable_clocks(dev);
581
582	if (cpu_is_omap15xx())
583		dev->rev1 = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) < 0x20;
584
585	/* reset ASAP, clearing any IRQs */
586	omap_i2c_init(dev);
587
588	r = request_irq(dev->irq, dev->rev1 ? omap_i2c_rev1_isr : omap_i2c_isr,
589			0, pdev->name, dev);
590
591	if (r) {
592		dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
593		goto err_unuse_clocks;
594	}
595	r = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
596	dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
597		 pdev->id, r >> 4, r & 0xf, clock);
598
599	adap = &dev->adapter;
600	i2c_set_adapdata(adap, dev);
601	adap->owner = THIS_MODULE;
602	adap->class = I2C_CLASS_HWMON;
603	strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
604	adap->algo = &omap_i2c_algo;
605	adap->dev.parent = &pdev->dev;
606
607	/* i2c device drivers may be active on return from add_adapter() */
608	adap->nr = pdev->id;
609	r = i2c_add_numbered_adapter(adap);
610	if (r) {
611		dev_err(dev->dev, "failure adding adapter\n");
612		goto err_free_irq;
613	}
614
615	omap_i2c_disable_clocks(dev);
616
617	return 0;
618
619err_free_irq:
620	free_irq(dev->irq, dev);
621err_unuse_clocks:
622	omap_i2c_disable_clocks(dev);
623	omap_i2c_put_clocks(dev);
624err_free_mem:
625	platform_set_drvdata(pdev, NULL);
626	kfree(dev);
627err_release_region:
628	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
629	release_mem_region(mem->start, (mem->end - mem->start) + 1);
630
631	return r;
632}
633
634static int
635omap_i2c_remove(struct platform_device *pdev)
636{
637	struct omap_i2c_dev	*dev = platform_get_drvdata(pdev);
638	struct resource		*mem;
639
640	platform_set_drvdata(pdev, NULL);
641
642	free_irq(dev->irq, dev);
643	i2c_del_adapter(&dev->adapter);
644	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
645	omap_i2c_put_clocks(dev);
646	kfree(dev);
647	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
648	release_mem_region(mem->start, (mem->end - mem->start) + 1);
649	return 0;
650}
651
652static struct platform_driver omap_i2c_driver = {
653	.probe		= omap_i2c_probe,
654	.remove		= omap_i2c_remove,
655	.driver		= {
656		.name	= "i2c_omap",
657		.owner	= THIS_MODULE,
658	},
659};
660
661/* I2C may be needed to bring up other drivers */
662static int __init
663omap_i2c_init_driver(void)
664{
665	return platform_driver_register(&omap_i2c_driver);
666}
667subsys_initcall(omap_i2c_init_driver);
668
669static void __exit omap_i2c_exit_driver(void)
670{
671	platform_driver_unregister(&omap_i2c_driver);
672}
673module_exit(omap_i2c_exit_driver);
674
675MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
676MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
677MODULE_LICENSE("GPL");
678