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