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 #include <linux/slab.h>
  51
  52 #include <mach/irqs.h>
  53 #include <mach/hardware.h>
  54 #include <mach/i2c.h>
  55
  56 /** Defines ********************************************************************
  57 *******************************************************************************/
  58
  59 /* This will be the driver name the kernel reports */
  60 #define DRIVER_NAME "imx-i2c"
  61
  62 /* Default value */
  63 #define IMX_I2C_BIT_RATE        100000  /* 100kHz */
  64
  65 /* IMX I2C registers */
  66 #define IMX_I2C_IADR    0x00    /* i2c slave address */
  67 #define IMX_I2C_IFDR    0x04    /* i2c frequency divider */
  68 #define IMX_I2C_I2CR    0x08    /* i2c control */
  69 #define IMX_I2C_I2SR    0x0C    /* i2c status */
  70 #define IMX_I2C_I2DR    0x10    /* i2c transfer data */
  71
  72 /* Bits of IMX I2C registers */
  73 #define I2SR_RXAK       0x01
  74 #define I2SR_IIF        0x02
  75 #define I2SR_SRW        0x04
  76 #define I2SR_IAL        0x10
  77 #define I2SR_IBB        0x20
  78 #define I2SR_IAAS       0x40
  79 #define I2SR_ICF        0x80
  80 #define I2CR_RSTA       0x04
  81 #define I2CR_TXAK       0x08
  82 #define I2CR_MTX        0x10
  83 #define I2CR_MSTA       0x20
  84 #define I2CR_IIEN       0x40
  85 #define I2CR_IEN        0x80
  86
  87 /** Variables ******************************************************************
  88 *******************************************************************************/
  89
  90 /*
  91  * sorted list of clock divider, register value pairs
  92  * taken from table 26-5, p.26-9, Freescale i.MX
  93  * Integrated Portable System Processor Reference Manual
  94  * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
  95  *
  96  * Duplicated divider values removed from list
  97  */
  98
  99 static u16 __initdata i2c_clk_div[50][2] = {
 100         { 22,   0x20 }, { 24,   0x21 }, { 26,   0x22 }, { 28,   0x23 },
 101         { 30,   0x00 }, { 32,   0x24 }, { 36,   0x25 }, { 40,   0x26 },
 102         { 42,   0x03 }, { 44,   0x27 }, { 48,   0x28 }, { 52,   0x05 },
 103         { 56,   0x29 }, { 60,   0x06 }, { 64,   0x2A }, { 72,   0x2B },
 104         { 80,   0x2C }, { 88,   0x09 }, { 96,   0x2D }, { 104,  0x0A },
 105         { 112,  0x2E }, { 128,  0x2F }, { 144,  0x0C }, { 160,  0x30 },
 106         { 192,  0x31 }, { 224,  0x32 }, { 240,  0x0F }, { 256,  0x33 },
 107         { 288,  0x10 }, { 320,  0x34 }, { 384,  0x35 }, { 448,  0x36 },
 108         { 480,  0x13 }, { 512,  0x37 }, { 576,  0x14 }, { 640,  0x38 },
 109         { 768,  0x39 }, { 896,  0x3A }, { 960,  0x17 }, { 1024, 0x3B },
 110         { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
 111         { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
 112         { 3072, 0x1E }, { 3840, 0x1F }
 113 };
 114
 115 struct imx_i2c_struct {
 116         struct i2c_adapter      adapter;
 117         struct resource         *res;
 118         struct clk              *clk;
 119         void __iomem            *base;
 120         int                     irq;
 121         wait_queue_head_t       queue;
 122         unsigned long           i2csr;
 123         unsigned int            disable_delay;
 124         int                     stopped;
 125         unsigned int            ifdr; /* IMX_I2C_IFDR */
 126 };
 127
 128 /** Functions for IMX I2C adapter driver ***************************************
 129 *******************************************************************************/
 130
 131 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 132 {
 133         unsigned long orig_jiffies = jiffies;
 134         unsigned int temp;
 135
 136         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 137
 138         while (1) {
 139                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 140                 if (for_busy && (temp & I2SR_IBB))
 141                         break;
 142                 if (!for_busy && !(temp & I2SR_IBB))
 143                         break;
 144                 if (signal_pending(current)) {
 145                         dev_dbg(&i2c_imx->adapter.dev,
 146                                 "<%s> I2C Interrupted\n", __func__);
 147                         return -EINTR;
 148                 }
 149                 if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
 150                         dev_dbg(&i2c_imx->adapter.dev,
 151                                 "<%s> I2C bus is busy\n", __func__);
 152                         return -ETIMEDOUT;
 153                 }
 154                 schedule();
 155         }
 156
 157         return 0;
 158 }
 159
 160 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
 161 {
 162         wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
 163
 164         if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
 165                 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
 166                 return -ETIMEDOUT;
 167         }
 168         dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
 169         i2c_imx->i2csr = 0;
 170         return 0;
 171 }
 172
 173 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
 174 {
 175         if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
 176                 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
 177                 return -EIO;  /* No ACK */
 178         }
 179
 180         dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
 181         return 0;
 182 }
 183
 184 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 185 {
 186         unsigned int temp = 0;
 187         int result;
 188
 189         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 190
 191         clk_enable(i2c_imx->clk);
 192         writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
 193         /* Enable I2C controller */
 194         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 195         writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
 196
 197         /* Wait controller to be stable */
 198         udelay(50);
 199
 200         /* Start I2C transaction */
 201         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 202         temp |= I2CR_MSTA;
 203         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 204         result = i2c_imx_bus_busy(i2c_imx, 1);
 205         if (result)
 206                 return result;
 207         i2c_imx->stopped = 0;
 208
 209         temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 210         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 211         return result;
 212 }
 213
 214 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 215 {
 216         unsigned int temp = 0;
 217
 218         if (!i2c_imx->stopped) {
 219                 /* Stop I2C transaction */
 220                 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 221                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 222                 temp &= ~(I2CR_MSTA | I2CR_MTX);
 223                 writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 224         }
 225         if (cpu_is_mx1()) {
 226                 /*
 227                  * This delay caused by an i.MXL hardware bug.
 228                  * If no (or too short) delay, no "STOP" bit will be generated.
 229                  */
 230                 udelay(i2c_imx->disable_delay);
 231         }
 232
 233         if (!i2c_imx->stopped) {
 234                 i2c_imx_bus_busy(i2c_imx, 0);
 235                 i2c_imx->stopped = 1;
 236         }
 237
 238         /* Disable I2C controller */
 239         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 240         clk_disable(i2c_imx->clk);
 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         /* Store divider value */
 261         i2c_imx->ifdr = i2c_clk_div[i][1];
 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(&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                 if (result)
 442                         goto fail0;
 443         }
 444
 445 fail0:
 446         /* Stop I2C transfer */
 447         i2c_imx_stop(i2c_imx);
 448
 449         dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
 450                 (result < 0) ? "error" : "success msg",
 451                         (result < 0) ? result : num);
 452         return (result < 0) ? result : num;
 453 }
 454
 455 static u32 i2c_imx_func(struct i2c_adapter *adapter)
 456 {
 457         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 458 }
 459
 460 static struct i2c_algorithm i2c_imx_algo = {
 461         .master_xfer    = i2c_imx_xfer,
 462         .functionality  = i2c_imx_func,
 463 };
 464
 465 static int __init i2c_imx_probe(struct platform_device *pdev)
 466 {
 467         struct imx_i2c_struct *i2c_imx;
 468         struct resource *res;
 469         struct imxi2c_platform_data *pdata;
 470         void __iomem *base;
 471         resource_size_t res_size;
 472         int irq;
 473         int ret;
 474
 475         dev_dbg(&pdev->dev, "<%s>\n", __func__);
 476
 477         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 478         if (!res) {
 479                 dev_err(&pdev->dev, "can't get device resources\n");
 480                 return -ENOENT;
 481         }
 482         irq = platform_get_irq(pdev, 0);
 483         if (irq < 0) {
 484                 dev_err(&pdev->dev, "can't get irq number\n");
 485                 return -ENOENT;
 486         }
 487
 488         pdata = pdev->dev.platform_data;
 489
 490         if (pdata && pdata->init) {
 491                 ret = pdata->init(&pdev->dev);
 492                 if (ret)
 493                         return ret;
 494         }
 495
 496         res_size = resource_size(res);
 497
 498         if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
 499                 ret = -EBUSY;
 500                 goto fail0;
 501         }
 502
 503         base = ioremap(res->start, res_size);
 504         if (!base) {
 505                 dev_err(&pdev->dev, "ioremap failed\n");
 506                 ret = -EIO;
 507                 goto fail1;
 508         }
 509
 510         i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
 511         if (!i2c_imx) {
 512                 dev_err(&pdev->dev, "can't allocate interface\n");
 513                 ret = -ENOMEM;
 514                 goto fail2;
 515         }
 516
 517         /* Setup i2c_imx driver structure */
 518         strcpy(i2c_imx->adapter.name, pdev->name);
 519         i2c_imx->adapter.owner          = THIS_MODULE;
 520         i2c_imx->adapter.algo           = &i2c_imx_algo;
 521         i2c_imx->adapter.dev.parent     = &pdev->dev;
 522         i2c_imx->adapter.nr             = pdev->id;
 523         i2c_imx->irq                    = irq;
 524         i2c_imx->base                   = base;
 525         i2c_imx->res                    = res;
 526
 527         /* Get I2C clock */
 528         i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
 529         if (IS_ERR(i2c_imx->clk)) {
 530                 ret = PTR_ERR(i2c_imx->clk);
 531                 dev_err(&pdev->dev, "can't get I2C clock\n");
 532                 goto fail3;
 533         }
 534
 535         /* Request IRQ */
 536         ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
 537         if (ret) {
 538                 dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
 539                 goto fail4;
 540         }
 541
 542         /* Init queue */
 543         init_waitqueue_head(&i2c_imx->queue);
 544
 545         /* Set up adapter data */
 546         i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
 547
 548         /* Set up clock divider */
 549         if (pdata && pdata->bitrate)
 550                 i2c_imx_set_clk(i2c_imx, pdata->bitrate);
 551         else
 552                 i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
 553
 554         /* Set up chip registers to defaults */
 555         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 556         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 557
 558         /* Add I2C adapter */
 559         ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
 560         if (ret < 0) {
 561                 dev_err(&pdev->dev, "registration failed\n");
 562                 goto fail5;
 563         }
 564
 565         /* Set up platform driver data */
 566         platform_set_drvdata(pdev, i2c_imx);
 567
 568         dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
 569         dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
 570                 i2c_imx->res->start, i2c_imx->res->end);
 571         dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
 572                 res_size, i2c_imx->res->start);
 573         dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
 574                 i2c_imx->adapter.name);
 575         dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
 576
 577         return 0;   /* Return OK */
 578
 579 fail5:
 580         free_irq(i2c_imx->irq, i2c_imx);
 581 fail4:
 582         clk_put(i2c_imx->clk);
 583 fail3:
 584         kfree(i2c_imx);
 585 fail2:
 586         iounmap(base);
 587 fail1:
 588         release_mem_region(res->start, resource_size(res));
 589 fail0:
 590         if (pdata && pdata->exit)
 591                 pdata->exit(&pdev->dev);
 592         return ret; /* Return error number */
 593 }
 594
 595 static int __exit i2c_imx_remove(struct platform_device *pdev)
 596 {
 597         struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
 598         struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
 599
 600         /* remove adapter */
 601         dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
 602         i2c_del_adapter(&i2c_imx->adapter);
 603         platform_set_drvdata(pdev, NULL);
 604
 605         /* free interrupt */
 606         free_irq(i2c_imx->irq, i2c_imx);
 607
 608         /* setup chip registers to defaults */
 609         writeb(0, i2c_imx->base + IMX_I2C_IADR);
 610         writeb(0, i2c_imx->base + IMX_I2C_IFDR);
 611         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 612         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 613
 614         /* Shut down hardware */
 615         if (pdata && pdata->exit)
 616                 pdata->exit(&pdev->dev);
 617
 618         clk_put(i2c_imx->clk);
 619
 620         iounmap(i2c_imx->base);
 621         release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
 622         kfree(i2c_imx);
 623         return 0;
 624 }
 625
 626 static struct platform_driver i2c_imx_driver = {
 627         .remove         = __exit_p(i2c_imx_remove),
 628         .driver = {
 629                 .name   = DRIVER_NAME,
 630                 .owner  = THIS_MODULE,
 631         }
 632 };
 633
 634 static int __init i2c_adap_imx_init(void)
 635 {
 636         return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
 637 }
 638 subsys_initcall(i2c_adap_imx_init);
 639
 640 static void __exit i2c_adap_imx_exit(void)
 641 {
 642         platform_driver_unregister(&i2c_imx_driver);
 643 }
 644 module_exit(i2c_adap_imx_exit);
 645
 646 MODULE_LICENSE("GPL");
 647 MODULE_AUTHOR("Darius Augulis");
 648 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
 649 MODULE_ALIAS("platform:" DRIVER_NAME);