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         int                     stopped;
 124         unsigned int            ifdr; /* IMX_I2C_IFDR */
 125 };
 126
 127 /** Functions for IMX I2C adapter driver ***************************************
 128 *******************************************************************************/
 129
 130 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 131 {
 132         unsigned long orig_jiffies = jiffies;
 133         unsigned int temp;
 134
 135         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 136
 137         while (1) {
 138                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 139                 if (for_busy && (temp & I2SR_IBB))
 140                         break;
 141                 if (!for_busy && !(temp & I2SR_IBB))
 142                         break;
 143                 if (signal_pending(current)) {
 144                         dev_dbg(&i2c_imx->adapter.dev,
 145                                 "<%s> I2C Interrupted\n", __func__);
 146                         return -EINTR;
 147                 }
 148                 if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
 149                         dev_dbg(&i2c_imx->adapter.dev,
 150                                 "<%s> I2C bus is busy\n", __func__);
 151                         return -EIO;
 152                 }
 153                 schedule();
 154         }
 155
 156         return 0;
 157 }
 158
 159 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
 160 {
 161         int result;
 162
 163         result = wait_event_interruptible_timeout(i2c_imx->queue,
 164                 i2c_imx->i2csr & I2SR_IIF, HZ / 10);
 165
 166         if (unlikely(result < 0)) {
 167                 dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__);
 168                 return result;
 169         } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
 170                 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
 171                 return -ETIMEDOUT;
 172         }
 173         dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
 174         i2c_imx->i2csr = 0;
 175         return 0;
 176 }
 177
 178 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
 179 {
 180         if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
 181                 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
 182                 return -EIO;  /* No ACK */
 183         }
 184
 185         dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
 186         return 0;
 187 }
 188
 189 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 190 {
 191         unsigned int temp = 0;
 192         int result;
 193
 194         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 195
 196         clk_enable(i2c_imx->clk);
 197         writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
 198         /* Enable I2C controller */
 199         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 200         writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
 201
 202         /* Wait controller to be stable */
 203         udelay(50);
 204
 205         /* Start I2C transaction */
 206         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 207         temp |= I2CR_MSTA;
 208         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 209         result = i2c_imx_bus_busy(i2c_imx, 1);
 210         if (result)
 211                 return result;
 212         i2c_imx->stopped = 0;
 213
 214         temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 215         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 216         return result;
 217 }
 218
 219 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 220 {
 221         unsigned int temp = 0;
 222
 223         if (!i2c_imx->stopped) {
 224                 /* Stop I2C transaction */
 225                 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 226                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 227                 temp &= ~(I2CR_MSTA | I2CR_MTX);
 228                 writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 229         }
 230         if (cpu_is_mx1()) {
 231                 /*
 232                  * This delay caused by an i.MXL hardware bug.
 233                  * If no (or too short) delay, no "STOP" bit will be generated.
 234                  */
 235                 udelay(i2c_imx->disable_delay);
 236         }
 237
 238         if (!i2c_imx->stopped) {
 239                 i2c_imx_bus_busy(i2c_imx, 0);
 240                 i2c_imx->stopped = 1;
 241         }
 242
 243         /* Disable I2C controller */
 244         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 245         clk_disable(i2c_imx->clk);
 246 }
 247
 248 static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
 249                                                         unsigned int rate)
 250 {
 251         unsigned int i2c_clk_rate;
 252         unsigned int div;
 253         int i;
 254
 255         /* Divider value calculation */
 256         i2c_clk_rate = clk_get_rate(i2c_imx->clk);
 257         div = (i2c_clk_rate + rate - 1) / rate;
 258         if (div < i2c_clk_div[0][0])
 259                 i = 0;
 260         else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
 261                 i = ARRAY_SIZE(i2c_clk_div) - 1;
 262         else
 263                 for (i = 0; i2c_clk_div[i][0] < div; i++);
 264
 265         /* Store divider value */
 266         i2c_imx->ifdr = i2c_clk_div[i][1];
 267
 268         /*
 269          * There dummy delay is calculated.
 270          * It should be about one I2C clock period long.
 271          * This delay is used in I2C bus disable function
 272          * to fix chip hardware bug.
 273          */
 274         i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
 275                 + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
 276
 277         /* dev_dbg() can't be used, because adapter is not yet registered */
 278 #ifdef CONFIG_I2C_DEBUG_BUS
 279         printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
 280                 __func__, i2c_clk_rate, div);
 281         printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
 282                 __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
 283 #endif
 284 }
 285
 286 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
 287 {
 288         struct imx_i2c_struct *i2c_imx = dev_id;
 289         unsigned int temp;
 290
 291         temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 292         if (temp & I2SR_IIF) {
 293                 /* save status register */
 294                 i2c_imx->i2csr = temp;
 295                 temp &= ~I2SR_IIF;
 296                 writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
 297                 wake_up_interruptible(&i2c_imx->queue);
 298                 return IRQ_HANDLED;
 299         }
 300
 301         return IRQ_NONE;
 302 }
 303
 304 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 305 {
 306         int i, result;
 307
 308         dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
 309                 __func__, msgs->addr << 1);
 310
 311         /* write slave address */
 312         writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
 313         result = i2c_imx_trx_complete(i2c_imx);
 314         if (result)
 315                 return result;
 316         result = i2c_imx_acked(i2c_imx);
 317         if (result)
 318                 return result;
 319         dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
 320
 321         /* write data */
 322         for (i = 0; i < msgs->len; i++) {
 323                 dev_dbg(&i2c_imx->adapter.dev,
 324                         "<%s> write byte: B%d=0x%X\n",
 325                         __func__, i, msgs->buf[i]);
 326                 writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
 327                 result = i2c_imx_trx_complete(i2c_imx);
 328                 if (result)
 329                         return result;
 330                 result = i2c_imx_acked(i2c_imx);
 331                 if (result)
 332                         return result;
 333         }
 334         return 0;
 335 }
 336
 337 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 338 {
 339         int i, result;
 340         unsigned int temp;
 341
 342         dev_dbg(&i2c_imx->adapter.dev,
 343                 "<%s> write slave address: addr=0x%x\n",
 344                 __func__, (msgs->addr << 1) | 0x01);
 345
 346         /* write slave address */
 347         writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
 348         result = i2c_imx_trx_complete(i2c_imx);
 349         if (result)
 350                 return result;
 351         result = i2c_imx_acked(i2c_imx);
 352         if (result)
 353                 return result;
 354
 355         dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
 356
 357         /* setup bus to read data */
 358         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 359         temp &= ~I2CR_MTX;
 360         if (msgs->len - 1)
 361                 temp &= ~I2CR_TXAK;
 362         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 363         readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
 364
 365         dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
 366
 367         /* read data */
 368         for (i = 0; i < msgs->len; i++) {
 369                 result = i2c_imx_trx_complete(i2c_imx);
 370                 if (result)
 371                         return result;
 372                 if (i == (msgs->len - 1)) {
 373                         /* It must generate STOP before read I2DR to prevent
 374                            controller from generating another clock cycle */
 375                         dev_dbg(&i2c_imx->adapter.dev,
 376                                 "<%s> clear MSTA\n", __func__);
 377                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 378                         temp &= ~(I2CR_MSTA | I2CR_MTX);
 379                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 380                         i2c_imx_bus_busy(i2c_imx, 0);
 381                         i2c_imx->stopped = 1;
 382                 } else if (i == (msgs->len - 2)) {
 383                         dev_dbg(&i2c_imx->adapter.dev,
 384                                 "<%s> set TXAK\n", __func__);
 385                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 386                         temp |= I2CR_TXAK;
 387                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 388                 }
 389                 msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
 390                 dev_dbg(&i2c_imx->adapter.dev,
 391                         "<%s> read byte: B%d=0x%X\n",
 392                         __func__, i, msgs->buf[i]);
 393         }
 394         return 0;
 395 }
 396
 397 static int i2c_imx_xfer(struct i2c_adapter *adapter,
 398                                                 struct i2c_msg *msgs, int num)
 399 {
 400         unsigned int i, temp;
 401         int result;
 402         struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
 403
 404         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 405
 406         /* Start I2C transfer */
 407         result = i2c_imx_start(i2c_imx);
 408         if (result)
 409                 goto fail0;
 410
 411         /* read/write data */
 412         for (i = 0; i < num; i++) {
 413                 if (i) {
 414                         dev_dbg(&i2c_imx->adapter.dev,
 415                                 "<%s> repeated start\n", __func__);
 416                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 417                         temp |= I2CR_RSTA;
 418                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 419                         result =  i2c_imx_bus_busy(i2c_imx, 1);
 420                         if (result)
 421                                 goto fail0;
 422                 }
 423                 dev_dbg(&i2c_imx->adapter.dev,
 424                         "<%s> transfer message: %d\n", __func__, i);
 425                 /* write/read data */
 426 #ifdef CONFIG_I2C_DEBUG_BUS
 427                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 428                 dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
 429                         "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
 430                         (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
 431                         (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
 432                         (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
 433                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 434                 dev_dbg(&i2c_imx->adapter.dev,
 435                         "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
 436                         "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
 437                         (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
 438                         (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
 439                         (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
 440                         (temp & I2SR_RXAK ? 1 : 0));
 441 #endif
 442                 if (msgs[i].flags & I2C_M_RD)
 443                         result = i2c_imx_read(i2c_imx, &msgs[i]);
 444                 else
 445                         result = i2c_imx_write(i2c_imx, &msgs[i]);
 446         }
 447
 448 fail0:
 449         /* Stop I2C transfer */
 450         i2c_imx_stop(i2c_imx);
 451
 452         dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
 453                 (result < 0) ? "error" : "success msg",
 454                         (result < 0) ? result : num);
 455         return (result < 0) ? result : num;
 456 }
 457
 458 static u32 i2c_imx_func(struct i2c_adapter *adapter)
 459 {
 460         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 461 }
 462
 463 static struct i2c_algorithm i2c_imx_algo = {
 464         .master_xfer    = i2c_imx_xfer,
 465         .functionality  = i2c_imx_func,
 466 };
 467
 468 static int __init i2c_imx_probe(struct platform_device *pdev)
 469 {
 470         struct imx_i2c_struct *i2c_imx;
 471         struct resource *res;
 472         struct imxi2c_platform_data *pdata;
 473         void __iomem *base;
 474         resource_size_t res_size;
 475         int irq;
 476         int ret;
 477
 478         dev_dbg(&pdev->dev, "<%s>\n", __func__);
 479
 480         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 481         if (!res) {
 482                 dev_err(&pdev->dev, "can't get device resources\n");
 483                 return -ENOENT;
 484         }
 485         irq = platform_get_irq(pdev, 0);
 486         if (irq < 0) {
 487                 dev_err(&pdev->dev, "can't get irq number\n");
 488                 return -ENOENT;
 489         }
 490
 491         pdata = pdev->dev.platform_data;
 492
 493         if (pdata && pdata->init) {
 494                 ret = pdata->init(&pdev->dev);
 495                 if (ret)
 496                         return ret;
 497         }
 498
 499         res_size = resource_size(res);
 500
 501         if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
 502                 ret = -EBUSY;
 503                 goto fail0;
 504         }
 505
 506         base = ioremap(res->start, res_size);
 507         if (!base) {
 508                 dev_err(&pdev->dev, "ioremap failed\n");
 509                 ret = -EIO;
 510                 goto fail1;
 511         }
 512
 513         i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
 514         if (!i2c_imx) {
 515                 dev_err(&pdev->dev, "can't allocate interface\n");
 516                 ret = -ENOMEM;
 517                 goto fail2;
 518         }
 519
 520         /* Setup i2c_imx driver structure */
 521         strcpy(i2c_imx->adapter.name, pdev->name);
 522         i2c_imx->adapter.owner          = THIS_MODULE;
 523         i2c_imx->adapter.algo           = &i2c_imx_algo;
 524         i2c_imx->adapter.dev.parent     = &pdev->dev;
 525         i2c_imx->adapter.nr             = pdev->id;
 526         i2c_imx->irq                    = irq;
 527         i2c_imx->base                   = base;
 528         i2c_imx->res                    = res;
 529
 530         /* Get I2C clock */
 531         i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
 532         if (IS_ERR(i2c_imx->clk)) {
 533                 ret = PTR_ERR(i2c_imx->clk);
 534                 dev_err(&pdev->dev, "can't get I2C clock\n");
 535                 goto fail3;
 536         }
 537
 538         /* Request IRQ */
 539         ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
 540         if (ret) {
 541                 dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
 542                 goto fail4;
 543         }
 544
 545         /* Init queue */
 546         init_waitqueue_head(&i2c_imx->queue);
 547
 548         /* Set up adapter data */
 549         i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
 550
 551         /* Set up clock divider */
 552         if (pdata && pdata->bitrate)
 553                 i2c_imx_set_clk(i2c_imx, pdata->bitrate);
 554         else
 555                 i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
 556
 557         /* Set up chip registers to defaults */
 558         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 559         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 560
 561         /* Add I2C adapter */
 562         ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
 563         if (ret < 0) {
 564                 dev_err(&pdev->dev, "registration failed\n");
 565                 goto fail5;
 566         }
 567
 568         /* Set up platform driver data */
 569         platform_set_drvdata(pdev, i2c_imx);
 570
 571         dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
 572         dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
 573                 i2c_imx->res->start, i2c_imx->res->end);
 574         dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
 575                 res_size, i2c_imx->res->start);
 576         dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
 577                 i2c_imx->adapter.name);
 578         dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
 579
 580         return 0;   /* Return OK */
 581
 582 fail5:
 583         free_irq(i2c_imx->irq, i2c_imx);
 584 fail4:
 585         clk_put(i2c_imx->clk);
 586 fail3:
 587         kfree(i2c_imx);
 588 fail2:
 589         iounmap(base);
 590 fail1:
 591         release_mem_region(res->start, resource_size(res));
 592 fail0:
 593         if (pdata && pdata->exit)
 594                 pdata->exit(&pdev->dev);
 595         return ret; /* Return error number */
 596 }
 597
 598 static int __exit i2c_imx_remove(struct platform_device *pdev)
 599 {
 600         struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
 601         struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
 602
 603         /* remove adapter */
 604         dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
 605         i2c_del_adapter(&i2c_imx->adapter);
 606         platform_set_drvdata(pdev, NULL);
 607
 608         /* free interrupt */
 609         free_irq(i2c_imx->irq, i2c_imx);
 610
 611         /* setup chip registers to defaults */
 612         writeb(0, i2c_imx->base + IMX_I2C_IADR);
 613         writeb(0, i2c_imx->base + IMX_I2C_IFDR);
 614         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 615         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 616
 617         /* Shut down hardware */
 618         if (pdata && pdata->exit)
 619                 pdata->exit(&pdev->dev);
 620
 621         clk_put(i2c_imx->clk);
 622
 623         iounmap(i2c_imx->base);
 624         release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
 625         kfree(i2c_imx);
 626         return 0;
 627 }
 628
 629 static struct platform_driver i2c_imx_driver = {
 630         .remove         = __exit_p(i2c_imx_remove),
 631         .driver = {
 632                 .name   = DRIVER_NAME,
 633                 .owner  = THIS_MODULE,
 634         }
 635 };
 636
 637 static int __init i2c_adap_imx_init(void)
 638 {
 639         return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
 640 }
 641 subsys_initcall(i2c_adap_imx_init);
 642
 643 static void __exit i2c_adap_imx_exit(void)
 644 {
 645         platform_driver_unregister(&i2c_imx_driver);
 646 }
 647 module_exit(i2c_adap_imx_exit);
 648
 649 MODULE_LICENSE("GPL");
 650 MODULE_AUTHOR("Darius Augulis");
 651 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
 652 MODULE_ALIAS("platform:" DRIVER_NAME);