Merge branch 'topic/hda-cache' into topic/hda
[linux-2.6] / drivers / i2c / busses / i2c-imx.c
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
51 #include <mach/irqs.h>
52 #include <mach/hardware.h>
53 #include <mach/i2c.h>
54
55 /** Defines ********************************************************************
56 *******************************************************************************/
57
58 /* This will be the driver name the kernel reports */
59 #define DRIVER_NAME "imx-i2c"
60
61 /* Default value */
62 #define IMX_I2C_BIT_RATE        100000  /* 100kHz */
63
64 /* IMX I2C registers */
65 #define IMX_I2C_IADR    0x00    /* i2c slave address */
66 #define IMX_I2C_IFDR    0x04    /* i2c frequency divider */
67 #define IMX_I2C_I2CR    0x08    /* i2c control */
68 #define IMX_I2C_I2SR    0x0C    /* i2c status */
69 #define IMX_I2C_I2DR    0x10    /* i2c transfer data */
70
71 /* Bits of IMX I2C registers */
72 #define I2SR_RXAK       0x01
73 #define I2SR_IIF        0x02
74 #define I2SR_SRW        0x04
75 #define I2SR_IAL        0x10
76 #define I2SR_IBB        0x20
77 #define I2SR_IAAS       0x40
78 #define I2SR_ICF        0x80
79 #define I2CR_RSTA       0x04
80 #define I2CR_TXAK       0x08
81 #define I2CR_MTX        0x10
82 #define I2CR_MSTA       0x20
83 #define I2CR_IIEN       0x40
84 #define I2CR_IEN        0x80
85
86 /** Variables ******************************************************************
87 *******************************************************************************/
88
89 /*
90  * sorted list of clock divider, register value pairs
91  * taken from table 26-5, p.26-9, Freescale i.MX
92  * Integrated Portable System Processor Reference Manual
93  * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
94  *
95  * Duplicated divider values removed from list
96  */
97
98 static u16 __initdata i2c_clk_div[50][2] = {
99         { 22,   0x20 }, { 24,   0x21 }, { 26,   0x22 }, { 28,   0x23 },
100         { 30,   0x00 }, { 32,   0x24 }, { 36,   0x25 }, { 40,   0x26 },
101         { 42,   0x03 }, { 44,   0x27 }, { 48,   0x28 }, { 52,   0x05 },
102         { 56,   0x29 }, { 60,   0x06 }, { 64,   0x2A }, { 72,   0x2B },
103         { 80,   0x2C }, { 88,   0x09 }, { 96,   0x2D }, { 104,  0x0A },
104         { 112,  0x2E }, { 128,  0x2F }, { 144,  0x0C }, { 160,  0x30 },
105         { 192,  0x31 }, { 224,  0x32 }, { 240,  0x0F }, { 256,  0x33 },
106         { 288,  0x10 }, { 320,  0x34 }, { 384,  0x35 }, { 448,  0x36 },
107         { 480,  0x13 }, { 512,  0x37 }, { 576,  0x14 }, { 640,  0x38 },
108         { 768,  0x39 }, { 896,  0x3A }, { 960,  0x17 }, { 1024, 0x3B },
109         { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
110         { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
111         { 3072, 0x1E }, { 3840, 0x1F }
112 };
113
114 struct imx_i2c_struct {
115         struct i2c_adapter      adapter;
116         struct resource         *res;
117         struct clk              *clk;
118         void __iomem            *base;
119         int                     irq;
120         wait_queue_head_t       queue;
121         unsigned long           i2csr;
122         unsigned int            disable_delay;
123 };
124
125 /** Functions for IMX I2C adapter driver ***************************************
126 *******************************************************************************/
127
128 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx)
129 {
130         unsigned long orig_jiffies = jiffies;
131
132         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
133
134         /* wait for bus not busy */
135         while (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_IBB) {
136                 if (signal_pending(current)) {
137                         dev_dbg(&i2c_imx->adapter.dev,
138                                 "<%s> I2C Interrupted\n", __func__);
139                         return -EINTR;
140                 }
141                 if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
142                         dev_dbg(&i2c_imx->adapter.dev,
143                                 "<%s> I2C bus is busy\n", __func__);
144                         return -EIO;
145                 }
146                 schedule();
147         }
148
149         return 0;
150 }
151
152 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
153 {
154         int result;
155
156         result = wait_event_interruptible_timeout(i2c_imx->queue,
157                 i2c_imx->i2csr & I2SR_IIF, HZ / 10);
158
159         if (unlikely(result < 0)) {
160                 dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__);
161                 return result;
162         } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
163                 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
164                 return -ETIMEDOUT;
165         }
166         dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
167         i2c_imx->i2csr = 0;
168         return 0;
169 }
170
171 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
172 {
173         if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
174                 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
175                 return -EIO;  /* No ACK */
176         }
177
178         dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
179         return 0;
180 }
181
182 static void i2c_imx_start(struct imx_i2c_struct *i2c_imx)
183 {
184         unsigned int temp = 0;
185
186         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
187
188         /* Enable I2C controller */
189         writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
190         /* Start I2C transaction */
191         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
192         temp |= I2CR_MSTA;
193         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
194         temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
195         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
196 }
197
198 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
199 {
200         unsigned int temp = 0;
201
202         /* Stop I2C transaction */
203         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
204         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
205         temp &= ~I2CR_MSTA;
206         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
207         /* setup chip registers to defaults */
208         writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
209         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
210         /*
211          * This delay caused by an i.MXL hardware bug.
212          * If no (or too short) delay, no "STOP" bit will be generated.
213          */
214         udelay(i2c_imx->disable_delay);
215         /* Disable I2C controller */
216         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
217 }
218
219 static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
220                                                         unsigned int rate)
221 {
222         unsigned int i2c_clk_rate;
223         unsigned int div;
224         int i;
225
226         /* Divider value calculation */
227         i2c_clk_rate = clk_get_rate(i2c_imx->clk);
228         div = (i2c_clk_rate + rate - 1) / rate;
229         if (div < i2c_clk_div[0][0])
230                 i = 0;
231         else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
232                 i = ARRAY_SIZE(i2c_clk_div) - 1;
233         else
234                 for (i = 0; i2c_clk_div[i][0] < div; i++);
235
236         /* Write divider value to register */
237         writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);
238
239         /*
240          * There dummy delay is calculated.
241          * It should be about one I2C clock period long.
242          * This delay is used in I2C bus disable function
243          * to fix chip hardware bug.
244          */
245         i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
246                 + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
247
248         /* dev_dbg() can't be used, because adapter is not yet registered */
249 #ifdef CONFIG_I2C_DEBUG_BUS
250         printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
251                 __func__, i2c_clk_rate, div);
252         printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
253                 __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
254 #endif
255 }
256
257 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
258 {
259         struct imx_i2c_struct *i2c_imx = dev_id;
260         unsigned int temp;
261
262         temp = readb(i2c_imx->base + IMX_I2C_I2SR);
263         if (temp & I2SR_IIF) {
264                 /* save status register */
265                 i2c_imx->i2csr = temp;
266                 temp &= ~I2SR_IIF;
267                 writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
268                 wake_up_interruptible(&i2c_imx->queue);
269                 return IRQ_HANDLED;
270         }
271
272         return IRQ_NONE;
273 }
274
275 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
276 {
277         int i, result;
278
279         dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
280                 __func__, msgs->addr << 1);
281
282         /* write slave address */
283         writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
284         result = i2c_imx_trx_complete(i2c_imx);
285         if (result)
286                 return result;
287         result = i2c_imx_acked(i2c_imx);
288         if (result)
289                 return result;
290         dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
291
292         /* write data */
293         for (i = 0; i < msgs->len; i++) {
294                 dev_dbg(&i2c_imx->adapter.dev,
295                         "<%s> write byte: B%d=0x%X\n",
296                         __func__, i, msgs->buf[i]);
297                 writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
298                 result = i2c_imx_trx_complete(i2c_imx);
299                 if (result)
300                         return result;
301                 result = i2c_imx_acked(i2c_imx);
302                 if (result)
303                         return result;
304         }
305         return 0;
306 }
307
308 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
309 {
310         int i, result;
311         unsigned int temp;
312
313         dev_dbg(&i2c_imx->adapter.dev,
314                 "<%s> write slave address: addr=0x%x\n",
315                 __func__, (msgs->addr << 1) | 0x01);
316
317         /* write slave address */
318         writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
319         result = i2c_imx_trx_complete(i2c_imx);
320         if (result)
321                 return result;
322         result = i2c_imx_acked(i2c_imx);
323         if (result)
324                 return result;
325
326         dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
327
328         /* setup bus to read data */
329         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
330         temp &= ~I2CR_MTX;
331         if (msgs->len - 1)
332                 temp &= ~I2CR_TXAK;
333         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
334         readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
335
336         dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
337
338         /* read data */
339         for (i = 0; i < msgs->len; i++) {
340                 result = i2c_imx_trx_complete(i2c_imx);
341                 if (result)
342                         return result;
343                 if (i == (msgs->len - 1)) {
344                         dev_dbg(&i2c_imx->adapter.dev,
345                                 "<%s> clear MSTA\n", __func__);
346                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
347                         temp &= ~I2CR_MSTA;
348                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
349                 } else if (i == (msgs->len - 2)) {
350                         dev_dbg(&i2c_imx->adapter.dev,
351                                 "<%s> set TXAK\n", __func__);
352                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
353                         temp |= I2CR_TXAK;
354                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
355                 }
356                 msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
357                 dev_dbg(&i2c_imx->adapter.dev,
358                         "<%s> read byte: B%d=0x%X\n",
359                         __func__, i, msgs->buf[i]);
360         }
361         return 0;
362 }
363
364 static int i2c_imx_xfer(struct i2c_adapter *adapter,
365                                                 struct i2c_msg *msgs, int num)
366 {
367         unsigned int i, temp;
368         int result;
369         struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
370
371         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
372
373         /* Check if i2c bus is not busy */
374         result = i2c_imx_bus_busy(i2c_imx);
375         if (result)
376                 goto fail0;
377
378         /* Start I2C transfer */
379         i2c_imx_start(i2c_imx);
380
381         /* read/write data */
382         for (i = 0; i < num; i++) {
383                 if (i) {
384                         dev_dbg(&i2c_imx->adapter.dev,
385                                 "<%s> repeated start\n", __func__);
386                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
387                         temp |= I2CR_RSTA;
388                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
389                 }
390                 dev_dbg(&i2c_imx->adapter.dev,
391                         "<%s> transfer message: %d\n", __func__, i);
392                 /* write/read data */
393 #ifdef CONFIG_I2C_DEBUG_BUS
394                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
395                 dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
396                         "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
397                         (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
398                         (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
399                         (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
400                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
401                 dev_dbg(&i2c_imx->adapter.dev,
402                         "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
403                         "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
404                         (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
405                         (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
406                         (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
407                         (temp & I2SR_RXAK ? 1 : 0));
408 #endif
409                 if (msgs[i].flags & I2C_M_RD)
410                         result = i2c_imx_read(i2c_imx, &msgs[i]);
411                 else
412                         result = i2c_imx_write(i2c_imx, &msgs[i]);
413         }
414
415 fail0:
416         /* Stop I2C transfer */
417         i2c_imx_stop(i2c_imx);
418
419         dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
420                 (result < 0) ? "error" : "success msg",
421                         (result < 0) ? result : num);
422         return (result < 0) ? result : num;
423 }
424
425 static u32 i2c_imx_func(struct i2c_adapter *adapter)
426 {
427         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
428 }
429
430 static struct i2c_algorithm i2c_imx_algo = {
431         .master_xfer    = i2c_imx_xfer,
432         .functionality  = i2c_imx_func,
433 };
434
435 static int __init i2c_imx_probe(struct platform_device *pdev)
436 {
437         struct imx_i2c_struct *i2c_imx;
438         struct resource *res;
439         struct imxi2c_platform_data *pdata;
440         void __iomem *base;
441         resource_size_t res_size;
442         int irq;
443         int ret;
444
445         dev_dbg(&pdev->dev, "<%s>\n", __func__);
446
447         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
448         if (!res) {
449                 dev_err(&pdev->dev, "can't get device resources\n");
450                 return -ENOENT;
451         }
452         irq = platform_get_irq(pdev, 0);
453         if (irq < 0) {
454                 dev_err(&pdev->dev, "can't get irq number\n");
455                 return -ENOENT;
456         }
457
458         pdata = pdev->dev.platform_data;
459
460         if (pdata && pdata->init) {
461                 ret = pdata->init(&pdev->dev);
462                 if (ret)
463                         return ret;
464         }
465
466         res_size = resource_size(res);
467         base = ioremap(res->start, res_size);
468         if (!base) {
469                 dev_err(&pdev->dev, "ioremap failed\n");
470                 ret = -EIO;
471                 goto fail0;
472         }
473
474         i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
475         if (!i2c_imx) {
476                 dev_err(&pdev->dev, "can't allocate interface\n");
477                 ret = -ENOMEM;
478                 goto fail1;
479         }
480
481         if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
482                 ret = -EBUSY;
483                 goto fail2;
484         }
485
486         /* Setup i2c_imx driver structure */
487         strcpy(i2c_imx->adapter.name, pdev->name);
488         i2c_imx->adapter.owner          = THIS_MODULE;
489         i2c_imx->adapter.algo           = &i2c_imx_algo;
490         i2c_imx->adapter.dev.parent     = &pdev->dev;
491         i2c_imx->adapter.nr             = pdev->id;
492         i2c_imx->irq                    = irq;
493         i2c_imx->base                   = base;
494         i2c_imx->res                    = res;
495
496         /* Get I2C clock */
497         i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
498         if (IS_ERR(i2c_imx->clk)) {
499                 ret = PTR_ERR(i2c_imx->clk);
500                 dev_err(&pdev->dev, "can't get I2C clock\n");
501                 goto fail3;
502         }
503         clk_enable(i2c_imx->clk);
504
505         /* Request IRQ */
506         ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
507         if (ret) {
508                 dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
509                 goto fail4;
510         }
511
512         /* Init queue */
513         init_waitqueue_head(&i2c_imx->queue);
514
515         /* Set up adapter data */
516         i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
517
518         /* Set up clock divider */
519         if (pdata && pdata->bitrate)
520                 i2c_imx_set_clk(i2c_imx, pdata->bitrate);
521         else
522                 i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
523
524         /* Set up chip registers to defaults */
525         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
526         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
527
528         /* Add I2C adapter */
529         ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
530         if (ret < 0) {
531                 dev_err(&pdev->dev, "registration failed\n");
532                 goto fail5;
533         }
534
535         /* Set up platform driver data */
536         platform_set_drvdata(pdev, i2c_imx);
537
538         dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
539         dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
540                 i2c_imx->res->start, i2c_imx->res->end);
541         dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
542                 res_size, i2c_imx->res->start);
543         dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
544                 i2c_imx->adapter.name);
545         dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
546
547         return 0;   /* Return OK */
548
549 fail5:
550         free_irq(i2c_imx->irq, i2c_imx);
551 fail4:
552         clk_disable(i2c_imx->clk);
553         clk_put(i2c_imx->clk);
554 fail3:
555         release_mem_region(i2c_imx->res->start, resource_size(res));
556 fail2:
557         kfree(i2c_imx);
558 fail1:
559         iounmap(base);
560 fail0:
561         if (pdata && pdata->exit)
562                 pdata->exit(&pdev->dev);
563         return ret; /* Return error number */
564 }
565
566 static int __exit i2c_imx_remove(struct platform_device *pdev)
567 {
568         struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
569         struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
570
571         /* remove adapter */
572         dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
573         i2c_del_adapter(&i2c_imx->adapter);
574         platform_set_drvdata(pdev, NULL);
575
576         /* free interrupt */
577         free_irq(i2c_imx->irq, i2c_imx);
578
579         /* setup chip registers to defaults */
580         writeb(0, i2c_imx->base + IMX_I2C_IADR);
581         writeb(0, i2c_imx->base + IMX_I2C_IFDR);
582         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
583         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
584
585         /* Shut down hardware */
586         if (pdata && pdata->exit)
587                 pdata->exit(&pdev->dev);
588
589         /* Disable I2C clock */
590         clk_disable(i2c_imx->clk);
591         clk_put(i2c_imx->clk);
592
593         release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
594         iounmap(i2c_imx->base);
595         kfree(i2c_imx);
596         return 0;
597 }
598
599 static struct platform_driver i2c_imx_driver = {
600         .probe          = i2c_imx_probe,
601         .remove         = __exit_p(i2c_imx_remove),
602         .driver = {
603                 .name   = DRIVER_NAME,
604                 .owner  = THIS_MODULE,
605         }
606 };
607
608 static int __init i2c_adap_imx_init(void)
609 {
610         return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
611 }
612
613 static void __exit i2c_adap_imx_exit(void)
614 {
615         platform_driver_unregister(&i2c_imx_driver);
616 }
617
618 module_init(i2c_adap_imx_init);
619 module_exit(i2c_adap_imx_exit);
620
621 MODULE_LICENSE("GPL");
622 MODULE_AUTHOR("Darius Augulis");
623 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
624 MODULE_ALIAS("platform:" DRIVER_NAME);