SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 };
 125
 126 /** Functions for IMX I2C adapter driver ***************************************
 127 *******************************************************************************/
 128
 129 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 130 {
 131         unsigned long orig_jiffies = jiffies;
 132         unsigned int temp;
 133
 134         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 135
 136         while (1) {
 137                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 138                 if (for_busy && (temp & I2SR_IBB))
 139                         break;
 140                 if (!for_busy && !(temp & I2SR_IBB))
 141                         break;
 142                 if (signal_pending(current)) {
 143                         dev_dbg(&i2c_imx->adapter.dev,
 144                                 "<%s> I2C Interrupted\n", __func__);
 145                         return -EINTR;
 146                 }
 147                 if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
 148                         dev_dbg(&i2c_imx->adapter.dev,
 149                                 "<%s> I2C bus is busy\n", __func__);
 150                         return -EIO;
 151                 }
 152                 schedule();
 153         }
 154
 155         return 0;
 156 }
 157
 158 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
 159 {
 160         int result;
 161
 162         result = wait_event_interruptible_timeout(i2c_imx->queue,
 163                 i2c_imx->i2csr & I2SR_IIF, HZ / 10);
 164
 165         if (unlikely(result < 0)) {
 166                 dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__);
 167                 return result;
 168         } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
 169                 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
 170                 return -ETIMEDOUT;
 171         }
 172         dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
 173         i2c_imx->i2csr = 0;
 174         return 0;
 175 }
 176
 177 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
 178 {
 179         if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
 180                 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
 181                 return -EIO;  /* No ACK */
 182         }
 183
 184         dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
 185         return 0;
 186 }
 187
 188 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 189 {
 190         unsigned int temp = 0;
 191         int result;
 192
 193         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 194
 195         /* Enable I2C controller */
 196         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 197         writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
 198
 199         /* Wait controller to be stable */
 200         udelay(50);
 201
 202         /* Start I2C transaction */
 203         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 204         temp |= I2CR_MSTA;
 205         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 206         result = i2c_imx_bus_busy(i2c_imx, 1);
 207         if (result)
 208                 return result;
 209         i2c_imx->stopped = 0;
 210
 211         temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 212         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 213         return result;
 214 }
 215
 216 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 217 {
 218         unsigned int temp = 0;
 219
 220         if (!i2c_imx->stopped) {
 221                 /* Stop I2C transaction */
 222                 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 223                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 224                 temp &= ~(I2CR_MSTA | I2CR_MTX);
 225                 writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 226                 i2c_imx->stopped = 1;
 227         }
 228         if (cpu_is_mx1()) {
 229                 /*
 230                  * This delay caused by an i.MXL hardware bug.
 231                  * If no (or too short) delay, no "STOP" bit will be generated.
 232                  */
 233                 udelay(i2c_imx->disable_delay);
 234         }
 235
 236         if (!i2c_imx->stopped)
 237                 i2c_imx_bus_busy(i2c_imx, 0);
 238
 239         /* Disable I2C controller */
 240         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 241 }
 242
 243 static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
 244                                                         unsigned int rate)
 245 {
 246         unsigned int i2c_clk_rate;
 247         unsigned int div;
 248         int i;
 249
 250         /* Divider value calculation */
 251         i2c_clk_rate = clk_get_rate(i2c_imx->clk);
 252         div = (i2c_clk_rate + rate - 1) / rate;
 253         if (div < i2c_clk_div[0][0])
 254                 i = 0;
 255         else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
 256                 i = ARRAY_SIZE(i2c_clk_div) - 1;
 257         else
 258                 for (i = 0; i2c_clk_div[i][0] < div; i++);
 259
 260         /* Write divider value to register */
 261         writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);
 262
 263         /*
 264          * There dummy delay is calculated.
 265          * It should be about one I2C clock period long.
 266          * This delay is used in I2C bus disable function
 267          * to fix chip hardware bug.
 268          */
 269         i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
 270                 + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
 271
 272         /* dev_dbg() can't be used, because adapter is not yet registered */
 273 #ifdef CONFIG_I2C_DEBUG_BUS
 274         printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
 275                 __func__, i2c_clk_rate, div);
 276         printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
 277                 __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
 278 #endif
 279 }
 280
 281 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
 282 {
 283         struct imx_i2c_struct *i2c_imx = dev_id;
 284         unsigned int temp;
 285
 286         temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 287         if (temp & I2SR_IIF) {
 288                 /* save status register */
 289                 i2c_imx->i2csr = temp;
 290                 temp &= ~I2SR_IIF;
 291                 writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
 292                 wake_up_interruptible(&i2c_imx->queue);
 293                 return IRQ_HANDLED;
 294         }
 295
 296         return IRQ_NONE;
 297 }
 298
 299 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 300 {
 301         int i, result;
 302
 303         dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
 304                 __func__, msgs->addr << 1);
 305
 306         /* write slave address */
 307         writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
 308         result = i2c_imx_trx_complete(i2c_imx);
 309         if (result)
 310                 return result;
 311         result = i2c_imx_acked(i2c_imx);
 312         if (result)
 313                 return result;
 314         dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
 315
 316         /* write data */
 317         for (i = 0; i < msgs->len; i++) {
 318                 dev_dbg(&i2c_imx->adapter.dev,
 319                         "<%s> write byte: B%d=0x%X\n",
 320                         __func__, i, msgs->buf[i]);
 321                 writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
 322                 result = i2c_imx_trx_complete(i2c_imx);
 323                 if (result)
 324                         return result;
 325                 result = i2c_imx_acked(i2c_imx);
 326                 if (result)
 327                         return result;
 328         }
 329         return 0;
 330 }
 331
 332 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 333 {
 334         int i, result;
 335         unsigned int temp;
 336
 337         dev_dbg(&i2c_imx->adapter.dev,
 338                 "<%s> write slave address: addr=0x%x\n",
 339                 __func__, (msgs->addr << 1) | 0x01);
 340
 341         /* write slave address */
 342         writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
 343         result = i2c_imx_trx_complete(i2c_imx);
 344         if (result)
 345                 return result;
 346         result = i2c_imx_acked(i2c_imx);
 347         if (result)
 348                 return result;
 349
 350         dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
 351
 352         /* setup bus to read data */
 353         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 354         temp &= ~I2CR_MTX;
 355         if (msgs->len - 1)
 356                 temp &= ~I2CR_TXAK;
 357         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 358         readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
 359
 360         dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
 361
 362         /* read data */
 363         for (i = 0; i < msgs->len; i++) {
 364                 result = i2c_imx_trx_complete(i2c_imx);
 365                 if (result)
 366                         return result;
 367                 if (i == (msgs->len - 1)) {
 368                         /* It must generate STOP before read I2DR to prevent
 369                            controller from generating another clock cycle */
 370                         dev_dbg(&i2c_imx->adapter.dev,
 371                                 "<%s> clear MSTA\n", __func__);
 372                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 373                         temp &= ~(I2CR_MSTA | I2CR_MTX);
 374                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 375                         i2c_imx_bus_busy(i2c_imx, 0);
 376                         i2c_imx->stopped = 1;
 377                 } else if (i == (msgs->len - 2)) {
 378                         dev_dbg(&i2c_imx->adapter.dev,
 379                                 "<%s> set TXAK\n", __func__);
 380                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 381                         temp |= I2CR_TXAK;
 382                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 383                 }
 384                 msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
 385                 dev_dbg(&i2c_imx->adapter.dev,
 386                         "<%s> read byte: B%d=0x%X\n",
 387                         __func__, i, msgs->buf[i]);
 388         }
 389         return 0;
 390 }
 391
 392 static int i2c_imx_xfer(struct i2c_adapter *adapter,
 393                                                 struct i2c_msg *msgs, int num)
 394 {
 395         unsigned int i, temp;
 396         int result;
 397         struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
 398
 399         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 400
 401         /* Start I2C transfer */
 402         result = i2c_imx_start(i2c_imx);
 403         if (result)
 404                 goto fail0;
 405
 406         /* read/write data */
 407         for (i = 0; i < num; i++) {
 408                 if (i) {
 409                         dev_dbg(&i2c_imx->adapter.dev,
 410                                 "<%s> repeated start\n", __func__);
 411                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 412                         temp |= I2CR_RSTA;
 413                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 414                         result =  i2c_imx_bus_busy(i2c_imx, 1);
 415                         if (result)
 416                                 goto fail0;
 417                 }
 418                 dev_dbg(&i2c_imx->adapter.dev,
 419                         "<%s> transfer message: %d\n", __func__, i);
 420                 /* write/read data */
 421 #ifdef CONFIG_I2C_DEBUG_BUS
 422                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 423                 dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
 424                         "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
 425                         (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
 426                         (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
 427                         (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
 428                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 429                 dev_dbg(&i2c_imx->adapter.dev,
 430                         "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
 431                         "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
 432                         (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
 433                         (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
 434                         (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
 435                         (temp & I2SR_RXAK ? 1 : 0));
 436 #endif
 437                 if (msgs[i].flags & I2C_M_RD)
 438                         result = i2c_imx_read(i2c_imx, &msgs[i]);
 439                 else
 440                         result = i2c_imx_write(i2c_imx, &msgs[i]);
 441         }
 442
 443 fail0:
 444         /* Stop I2C transfer */
 445         i2c_imx_stop(i2c_imx);
 446
 447         dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
 448                 (result < 0) ? "error" : "success msg",
 449                         (result < 0) ? result : num);
 450         return (result < 0) ? result : num;
 451 }
 452
 453 static u32 i2c_imx_func(struct i2c_adapter *adapter)
 454 {
 455         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 456 }
 457
 458 static struct i2c_algorithm i2c_imx_algo = {
 459         .master_xfer    = i2c_imx_xfer,
 460         .functionality  = i2c_imx_func,
 461 };
 462
 463 static int __init i2c_imx_probe(struct platform_device *pdev)
 464 {
 465         struct imx_i2c_struct *i2c_imx;
 466         struct resource *res;
 467         struct imxi2c_platform_data *pdata;
 468         void __iomem *base;
 469         resource_size_t res_size;
 470         int irq;
 471         int ret;
 472
 473         dev_dbg(&pdev->dev, "<%s>\n", __func__);
 474
 475         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 476         if (!res) {
 477                 dev_err(&pdev->dev, "can't get device resources\n");
 478                 return -ENOENT;
 479         }
 480         irq = platform_get_irq(pdev, 0);
 481         if (irq < 0) {
 482                 dev_err(&pdev->dev, "can't get irq number\n");
 483                 return -ENOENT;
 484         }
 485
 486         pdata = pdev->dev.platform_data;
 487
 488         if (pdata && pdata->init) {
 489                 ret = pdata->init(&pdev->dev);
 490                 if (ret)
 491                         return ret;
 492         }
 493
 494         res_size = resource_size(res);
 495         base = ioremap(res->start, res_size);
 496         if (!base) {
 497                 dev_err(&pdev->dev, "ioremap failed\n");
 498                 ret = -EIO;
 499                 goto fail0;
 500         }
 501
 502         i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
 503         if (!i2c_imx) {
 504                 dev_err(&pdev->dev, "can't allocate interface\n");
 505                 ret = -ENOMEM;
 506                 goto fail1;
 507         }
 508
 509         if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
 510                 ret = -EBUSY;
 511                 goto fail2;
 512         }
 513
 514         /* Setup i2c_imx driver structure */
 515         strcpy(i2c_imx->adapter.name, pdev->name);
 516         i2c_imx->adapter.owner          = THIS_MODULE;
 517         i2c_imx->adapter.algo           = &i2c_imx_algo;
 518         i2c_imx->adapter.dev.parent     = &pdev->dev;
 519         i2c_imx->adapter.nr             = pdev->id;
 520         i2c_imx->irq                    = irq;
 521         i2c_imx->base                   = base;
 522         i2c_imx->res                    = res;
 523
 524         /* Get I2C clock */
 525         i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
 526         if (IS_ERR(i2c_imx->clk)) {
 527                 ret = PTR_ERR(i2c_imx->clk);
 528                 dev_err(&pdev->dev, "can't get I2C clock\n");
 529                 goto fail3;
 530         }
 531         clk_enable(i2c_imx->clk);
 532
 533         /* Request IRQ */
 534         ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
 535         if (ret) {
 536                 dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
 537                 goto fail4;
 538         }
 539
 540         /* Init queue */
 541         init_waitqueue_head(&i2c_imx->queue);
 542
 543         /* Set up adapter data */
 544         i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
 545
 546         /* Set up clock divider */
 547         if (pdata && pdata->bitrate)
 548                 i2c_imx_set_clk(i2c_imx, pdata->bitrate);
 549         else
 550                 i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
 551
 552         /* Set up chip registers to defaults */
 553         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 554         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 555
 556         /* Add I2C adapter */
 557         ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
 558         if (ret < 0) {
 559                 dev_err(&pdev->dev, "registration failed\n");
 560                 goto fail5;
 561         }
 562
 563         /* Set up platform driver data */
 564         platform_set_drvdata(pdev, i2c_imx);
 565
 566         dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
 567         dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
 568                 i2c_imx->res->start, i2c_imx->res->end);
 569         dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
 570                 res_size, i2c_imx->res->start);
 571         dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
 572                 i2c_imx->adapter.name);
 573         dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
 574
 575         return 0;   /* Return OK */
 576
 577 fail5:
 578         free_irq(i2c_imx->irq, i2c_imx);
 579 fail4:
 580         clk_disable(i2c_imx->clk);
 581         clk_put(i2c_imx->clk);
 582 fail3:
 583         release_mem_region(i2c_imx->res->start, resource_size(res));
 584 fail2:
 585         kfree(i2c_imx);
 586 fail1:
 587         iounmap(base);
 588 fail0:
 589         if (pdata && pdata->exit)
 590                 pdata->exit(&pdev->dev);
 591         return ret; /* Return error number */
 592 }
 593
 594 static int __exit i2c_imx_remove(struct platform_device *pdev)
 595 {
 596         struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
 597         struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
 598
 599         /* remove adapter */
 600         dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
 601         i2c_del_adapter(&i2c_imx->adapter);
 602         platform_set_drvdata(pdev, NULL);
 603
 604         /* free interrupt */
 605         free_irq(i2c_imx->irq, i2c_imx);
 606
 607         /* setup chip registers to defaults */
 608         writeb(0, i2c_imx->base + IMX_I2C_IADR);
 609         writeb(0, i2c_imx->base + IMX_I2C_IFDR);
 610         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 611         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 612
 613         /* Shut down hardware */
 614         if (pdata && pdata->exit)
 615                 pdata->exit(&pdev->dev);
 616
 617         /* Disable I2C clock */
 618         clk_disable(i2c_imx->clk);
 619         clk_put(i2c_imx->clk);
 620
 621         release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
 622         iounmap(i2c_imx->base);
 623         kfree(i2c_imx);
 624         return 0;
 625 }
 626
 627 static struct platform_driver i2c_imx_driver = {
 628         .probe          = i2c_imx_probe,
 629         .remove         = __exit_p(i2c_imx_remove),
 630         .driver = {
 631                 .name   = DRIVER_NAME,
 632                 .owner  = THIS_MODULE,
 633         }
 634 };
 635
 636 static int __init i2c_adap_imx_init(void)
 637 {
 638         return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
 639 }
 640 subsys_initcall(i2c_adap_imx_init);
 641
 642 static void __exit i2c_adap_imx_exit(void)
 643 {
 644         platform_driver_unregister(&i2c_imx_driver);
 645 }
 646 module_exit(i2c_adap_imx_exit);
 647
 648 MODULE_LICENSE("GPL");
 649 MODULE_AUTHOR("Darius Augulis");
 650 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
 651 MODULE_ALIAS("platform:" DRIVER_NAME);