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   1 /*
   2  *      Copyright (C) 2002 Motorola GSG-China
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version 2
   7  *      of the License, or (at your option) any later version.
   8  *
   9  *      This program is distributed in the hope that it will be useful,
  10  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *      GNU General Public License for more details.
  13  *
  14  *      You should have received a copy of the GNU General Public License
  15  *      along with this program; if not, write to the Free Software
  16  *      Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
  17  *      USA.
  18  *
  19  * Author:
  20  *      Darius Augulis, Teltonika Inc.
  21  *
  22  * Desc.:
  23  *      Implementation of I2C Adapter/Algorithm Driver
  24  *      for I2C Bus integrated in Freescale i.MX/MXC processors
  25  *
  26  *      Derived from Motorola GSG China I2C example driver
  27  *
  28  *      Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
  29  *      Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
  30  *      Copyright (C) 2007 RightHand Technologies, Inc.
  31  *      Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
  32  *
  33  */
  34
  35 /** Includes *******************************************************************
  36 *******************************************************************************/
  37
  38 #include <linux/init.h>
  39 #include <linux/kernel.h>
  40 #include <linux/module.h>
  41 #include <linux/errno.h>
  42 #include <linux/err.h>
  43 #include <linux/interrupt.h>
  44 #include <linux/delay.h>
  45 #include <linux/i2c.h>
  46 #include <linux/io.h>
  47 #include <linux/sched.h>
  48 #include <linux/platform_device.h>
  49 #include <linux/clk.h>
  50
  51 #include <mach/irqs.h>
  52 #include <mach/hardware.h>
  53 #include <mach/i2c.h>
  54
  55 /** Defines ********************************************************************
  56 *******************************************************************************/
  57
  58 /* This will be the driver name the kernel reports */
  59 #define DRIVER_NAME "imx-i2c"
  60
  61 /* Default value */
  62 #define IMX_I2C_BIT_RATE        100000  /* 100kHz */
  63
  64 /* IMX I2C registers */
  65 #define IMX_I2C_IADR    0x00    /* i2c slave address */
  66 #define IMX_I2C_IFDR    0x04    /* i2c frequency divider */
  67 #define IMX_I2C_I2CR    0x08    /* i2c control */
  68 #define IMX_I2C_I2SR    0x0C    /* i2c status */
  69 #define IMX_I2C_I2DR    0x10    /* i2c transfer data */
  70
  71 /* Bits of IMX I2C registers */
  72 #define I2SR_RXAK       0x01
  73 #define I2SR_IIF        0x02
  74 #define I2SR_SRW        0x04
  75 #define I2SR_IAL        0x10
  76 #define I2SR_IBB        0x20
  77 #define I2SR_IAAS       0x40
  78 #define I2SR_ICF        0x80
  79 #define I2CR_RSTA       0x04
  80 #define I2CR_TXAK       0x08
  81 #define I2CR_MTX        0x10
  82 #define I2CR_MSTA       0x20
  83 #define I2CR_IIEN       0x40
  84 #define I2CR_IEN        0x80
  85
  86 /** Variables ******************************************************************
  87 *******************************************************************************/
  88
  89 /*
  90  * sorted list of clock divider, register value pairs
  91  * taken from table 26-5, p.26-9, Freescale i.MX
  92  * Integrated Portable System Processor Reference Manual
  93  * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
  94  *
  95  * Duplicated divider values removed from list
  96  */
  97
  98 static u16 __initdata i2c_clk_div[50][2] = {
  99         { 22,   0x20 }, { 24,   0x21 }, { 26,   0x22 }, { 28,   0x23 },
 100         { 30,   0x00 }, { 32,   0x24 }, { 36,   0x25 }, { 40,   0x26 },
 101         { 42,   0x03 }, { 44,   0x27 }, { 48,   0x28 }, { 52,   0x05 },
 102         { 56,   0x29 }, { 60,   0x06 }, { 64,   0x2A }, { 72,   0x2B },
 103         { 80,   0x2C }, { 88,   0x09 }, { 96,   0x2D }, { 104,  0x0A },
 104         { 112,  0x2E }, { 128,  0x2F }, { 144,  0x0C }, { 160,  0x30 },
 105         { 192,  0x31 }, { 224,  0x32 }, { 240,  0x0F }, { 256,  0x33 },
 106         { 288,  0x10 }, { 320,  0x34 }, { 384,  0x35 }, { 448,  0x36 },
 107         { 480,  0x13 }, { 512,  0x37 }, { 576,  0x14 }, { 640,  0x38 },
 108         { 768,  0x39 }, { 896,  0x3A }, { 960,  0x17 }, { 1024, 0x3B },
 109         { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
 110         { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
 111         { 3072, 0x1E }, { 3840, 0x1F }
 112 };
 113
 114 struct imx_i2c_struct {
 115         struct i2c_adapter      adapter;
 116         struct resource         *res;
 117         struct clk              *clk;
 118         void __iomem            *base;
 119         int                     irq;
 120         wait_queue_head_t       queue;
 121         unsigned long           i2csr;
 122         unsigned int            disable_delay;
 123 };
 124
 125 /** Functions for IMX I2C adapter driver ***************************************
 126 *******************************************************************************/
 127
 128 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx)
 129 {
 130         unsigned long orig_jiffies = jiffies;
 131
 132         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 133
 134         /* wait for bus not busy */
 135         while (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_IBB) {
 136                 if (signal_pending(current)) {
 137                         dev_dbg(&i2c_imx->adapter.dev,
 138                                 "<%s> I2C Interrupted\n", __func__);
 139                         return -EINTR;
 140                 }
 141                 if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
 142                         dev_dbg(&i2c_imx->adapter.dev,
 143                                 "<%s> I2C bus is busy\n", __func__);
 144                         return -EIO;
 145                 }
 146                 schedule();
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
 153 {
 154         int result;
 155
 156         result = wait_event_interruptible_timeout(i2c_imx->queue,
 157                 i2c_imx->i2csr & I2SR_IIF, HZ / 10);
 158
 159         if (unlikely(result < 0)) {
 160                 dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__);
 161                 return result;
 162         } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
 163                 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
 164                 return -ETIMEDOUT;
 165         }
 166         dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
 167         i2c_imx->i2csr = 0;
 168         return 0;
 169 }
 170
 171 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
 172 {
 173         if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
 174                 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
 175                 return -EIO;  /* No ACK */
 176         }
 177
 178         dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
 179         return 0;
 180 }
 181
 182 static void i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 183 {
 184         unsigned int temp = 0;
 185
 186         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 187
 188         /* Enable I2C controller */
 189         writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
 190         /* Start I2C transaction */
 191         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 192         temp |= I2CR_MSTA;
 193         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 194         temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 195         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 196 }
 197
 198 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 199 {
 200         unsigned int temp = 0;
 201
 202         /* Stop I2C transaction */
 203         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 204         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 205         temp &= ~I2CR_MSTA;
 206         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 207         /* setup chip registers to defaults */
 208         writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
 209         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 210         /*
 211          * This delay caused by an i.MXL hardware bug.
 212          * If no (or too short) delay, no "STOP" bit will be generated.
 213          */
 214         udelay(i2c_imx->disable_delay);
 215         /* Disable I2C controller */
 216         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 217 }
 218
 219 static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
 220                                                         unsigned int rate)
 221 {
 222         unsigned int i2c_clk_rate;
 223         unsigned int div;
 224         int i;
 225
 226         /* Divider value calculation */
 227         i2c_clk_rate = clk_get_rate(i2c_imx->clk);
 228         div = (i2c_clk_rate + rate - 1) / rate;
 229         if (div < i2c_clk_div[0][0])
 230                 i = 0;
 231         else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
 232                 i = ARRAY_SIZE(i2c_clk_div) - 1;
 233         else
 234                 for (i = 0; i2c_clk_div[i][0] < div; i++);
 235
 236         /* Write divider value to register */
 237         writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);
 238
 239         /*
 240          * There dummy delay is calculated.
 241          * It should be about one I2C clock period long.
 242          * This delay is used in I2C bus disable function
 243          * to fix chip hardware bug.
 244          */
 245         i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
 246                 + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
 247
 248         /* dev_dbg() can't be used, because adapter is not yet registered */
 249 #ifdef CONFIG_I2C_DEBUG_BUS
 250         printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
 251                 __func__, i2c_clk_rate, div);
 252         printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
 253                 __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
 254 #endif
 255 }
 256
 257 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
 258 {
 259         struct imx_i2c_struct *i2c_imx = dev_id;
 260         unsigned int temp;
 261
 262         temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 263         if (temp & I2SR_IIF) {
 264                 /* save status register */
 265                 i2c_imx->i2csr = temp;
 266                 temp &= ~I2SR_IIF;
 267                 writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
 268                 wake_up_interruptible(&i2c_imx->queue);
 269                 return IRQ_HANDLED;
 270         }
 271
 272         return IRQ_NONE;
 273 }
 274
 275 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 276 {
 277         int i, result;
 278
 279         dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
 280                 __func__, msgs->addr << 1);
 281
 282         /* write slave address */
 283         writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
 284         result = i2c_imx_trx_complete(i2c_imx);
 285         if (result)
 286                 return result;
 287         result = i2c_imx_acked(i2c_imx);
 288         if (result)
 289                 return result;
 290         dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
 291
 292         /* write data */
 293         for (i = 0; i < msgs->len; i++) {
 294                 dev_dbg(&i2c_imx->adapter.dev,
 295                         "<%s> write byte: B%d=0x%X\n",
 296                         __func__, i, msgs->buf[i]);
 297                 writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
 298                 result = i2c_imx_trx_complete(i2c_imx);
 299                 if (result)
 300                         return result;
 301                 result = i2c_imx_acked(i2c_imx);
 302                 if (result)
 303                         return result;
 304         }
 305         return 0;
 306 }
 307
 308 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 309 {
 310         int i, result;
 311         unsigned int temp;
 312
 313         dev_dbg(&i2c_imx->adapter.dev,
 314                 "<%s> write slave address: addr=0x%x\n",
 315                 __func__, (msgs->addr << 1) | 0x01);
 316
 317         /* write slave address */
 318         writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
 319         result = i2c_imx_trx_complete(i2c_imx);
 320         if (result)
 321                 return result;
 322         result = i2c_imx_acked(i2c_imx);
 323         if (result)
 324                 return result;
 325
 326         dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
 327
 328         /* setup bus to read data */
 329         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 330         temp &= ~I2CR_MTX;
 331         if (msgs->len - 1)
 332                 temp &= ~I2CR_TXAK;
 333         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 334         readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
 335
 336         dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
 337
 338         /* read data */
 339         for (i = 0; i < msgs->len; i++) {
 340                 result = i2c_imx_trx_complete(i2c_imx);
 341                 if (result)
 342                         return result;
 343                 if (i == (msgs->len - 1)) {
 344                         dev_dbg(&i2c_imx->adapter.dev,
 345                                 "<%s> clear MSTA\n", __func__);
 346                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 347                         temp &= ~I2CR_MSTA;
 348                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 349                 } else if (i == (msgs->len - 2)) {
 350                         dev_dbg(&i2c_imx->adapter.dev,
 351                                 "<%s> set TXAK\n", __func__);
 352                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 353                         temp |= I2CR_TXAK;
 354                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 355                 }
 356                 msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
 357                 dev_dbg(&i2c_imx->adapter.dev,
 358                         "<%s> read byte: B%d=0x%X\n",
 359                         __func__, i, msgs->buf[i]);
 360         }
 361         return 0;
 362 }
 363
 364 static int i2c_imx_xfer(struct i2c_adapter *adapter,
 365                                                 struct i2c_msg *msgs, int num)
 366 {
 367         unsigned int i, temp;
 368         int result;
 369         struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
 370
 371         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 372
 373         /* Check if i2c bus is not busy */
 374         result = i2c_imx_bus_busy(i2c_imx);
 375         if (result)
 376                 goto fail0;
 377
 378         /* Start I2C transfer */
 379         i2c_imx_start(i2c_imx);
 380
 381         /* read/write data */
 382         for (i = 0; i < num; i++) {
 383                 if (i) {
 384                         dev_dbg(&i2c_imx->adapter.dev,
 385                                 "<%s> repeated start\n", __func__);
 386                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 387                         temp |= I2CR_RSTA;
 388                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 389                 }
 390                 dev_dbg(&i2c_imx->adapter.dev,
 391                         "<%s> transfer message: %d\n", __func__, i);
 392                 /* write/read data */
 393 #ifdef CONFIG_I2C_DEBUG_BUS
 394                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 395                 dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
 396                         "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
 397                         (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
 398                         (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
 399                         (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
 400                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 401                 dev_dbg(&i2c_imx->adapter.dev,
 402                         "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
 403                         "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
 404                         (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
 405                         (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
 406                         (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
 407                         (temp & I2SR_RXAK ? 1 : 0));
 408 #endif
 409                 if (msgs[i].flags & I2C_M_RD)
 410                         result = i2c_imx_read(i2c_imx, &msgs[i]);
 411                 else
 412                         result = i2c_imx_write(i2c_imx, &msgs[i]);
 413         }
 414
 415 fail0:
 416         /* Stop I2C transfer */
 417         i2c_imx_stop(i2c_imx);
 418
 419         dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
 420                 (result < 0) ? "error" : "success msg",
 421                         (result < 0) ? result : num);
 422         return (result < 0) ? result : num;
 423 }
 424
 425 static u32 i2c_imx_func(struct i2c_adapter *adapter)
 426 {
 427         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 428 }
 429
 430 static struct i2c_algorithm i2c_imx_algo = {
 431         .master_xfer    = i2c_imx_xfer,
 432         .functionality  = i2c_imx_func,
 433 };
 434
 435 static int __init i2c_imx_probe(struct platform_device *pdev)
 436 {
 437         struct imx_i2c_struct *i2c_imx;
 438         struct resource *res;
 439         struct imxi2c_platform_data *pdata;
 440         void __iomem *base;
 441         resource_size_t res_size;
 442         int irq;
 443         int ret;
 444
 445         dev_dbg(&pdev->dev, "<%s>\n", __func__);
 446
 447         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 448         if (!res) {
 449                 dev_err(&pdev->dev, "can't get device resources\n");
 450                 return -ENOENT;
 451         }
 452         irq = platform_get_irq(pdev, 0);
 453         if (irq < 0) {
 454                 dev_err(&pdev->dev, "can't get irq number\n");
 455                 return -ENOENT;
 456         }
 457
 458         pdata = pdev->dev.platform_data;
 459
 460         if (pdata && pdata->init) {
 461                 ret = pdata->init(&pdev->dev);
 462                 if (ret)
 463                         return ret;
 464         }
 465
 466         res_size = resource_size(res);
 467         base = ioremap(res->start, res_size);
 468         if (!base) {
 469                 dev_err(&pdev->dev, "ioremap failed\n");
 470                 ret = -EIO;
 471                 goto fail0;
 472         }
 473
 474         i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
 475         if (!i2c_imx) {
 476                 dev_err(&pdev->dev, "can't allocate interface\n");
 477                 ret = -ENOMEM;
 478                 goto fail1;
 479         }
 480
 481         if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
 482                 ret = -EBUSY;
 483                 goto fail2;
 484         }
 485
 486         /* Setup i2c_imx driver structure */
 487         strcpy(i2c_imx->adapter.name, pdev->name);
 488         i2c_imx->adapter.owner          = THIS_MODULE;
 489         i2c_imx->adapter.algo           = &i2c_imx_algo;
 490         i2c_imx->adapter.dev.parent     = &pdev->dev;
 491         i2c_imx->adapter.nr             = pdev->id;
 492         i2c_imx->irq                    = irq;
 493         i2c_imx->base                   = base;
 494         i2c_imx->res                    = res;
 495
 496         /* Get I2C clock */
 497         i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
 498         if (IS_ERR(i2c_imx->clk)) {
 499                 ret = PTR_ERR(i2c_imx->clk);
 500                 dev_err(&pdev->dev, "can't get I2C clock\n");
 501                 goto fail3;
 502         }
 503         clk_enable(i2c_imx->clk);
 504
 505         /* Request IRQ */
 506         ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
 507         if (ret) {
 508                 dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
 509                 goto fail4;
 510         }
 511
 512         /* Init queue */
 513         init_waitqueue_head(&i2c_imx->queue);
 514
 515         /* Set up adapter data */
 516         i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
 517
 518         /* Set up clock divider */
 519         if (pdata && pdata->bitrate)
 520                 i2c_imx_set_clk(i2c_imx, pdata->bitrate);
 521         else
 522                 i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
 523
 524         /* Set up chip registers to defaults */
 525         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 526         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 527
 528         /* Add I2C adapter */
 529         ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
 530         if (ret < 0) {
 531                 dev_err(&pdev->dev, "registration failed\n");
 532                 goto fail5;
 533         }
 534
 535         /* Set up platform driver data */
 536         platform_set_drvdata(pdev, i2c_imx);
 537
 538         dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
 539         dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
 540                 i2c_imx->res->start, i2c_imx->res->end);
 541         dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
 542                 res_size, i2c_imx->res->start);
 543         dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
 544                 i2c_imx->adapter.name);
 545         dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
 546
 547         return 0;   /* Return OK */
 548
 549 fail5:
 550         free_irq(i2c_imx->irq, i2c_imx);
 551 fail4:
 552         clk_disable(i2c_imx->clk);
 553         clk_put(i2c_imx->clk);
 554 fail3:
 555         release_mem_region(i2c_imx->res->start, resource_size(res));
 556 fail2:
 557         kfree(i2c_imx);
 558 fail1:
 559         iounmap(base);
 560 fail0:
 561         if (pdata && pdata->exit)
 562                 pdata->exit(&pdev->dev);
 563         return ret; /* Return error number */
 564 }
 565
 566 static int __exit i2c_imx_remove(struct platform_device *pdev)
 567 {
 568         struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
 569         struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
 570
 571         /* remove adapter */
 572         dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
 573         i2c_del_adapter(&i2c_imx->adapter);
 574         platform_set_drvdata(pdev, NULL);
 575
 576         /* free interrupt */
 577         free_irq(i2c_imx->irq, i2c_imx);
 578
 579         /* setup chip registers to defaults */
 580         writeb(0, i2c_imx->base + IMX_I2C_IADR);
 581         writeb(0, i2c_imx->base + IMX_I2C_IFDR);
 582         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 583         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 584
 585         /* Shut down hardware */
 586         if (pdata && pdata->exit)
 587                 pdata->exit(&pdev->dev);
 588
 589         /* Disable I2C clock */
 590         clk_disable(i2c_imx->clk);
 591         clk_put(i2c_imx->clk);
 592
 593         release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
 594         iounmap(i2c_imx->base);
 595         kfree(i2c_imx);
 596         return 0;
 597 }
 598
 599 static struct platform_driver i2c_imx_driver = {
 600         .probe          = i2c_imx_probe,
 601         .remove         = __exit_p(i2c_imx_remove),
 602         .driver = {
 603                 .name   = DRIVER_NAME,
 604                 .owner  = THIS_MODULE,
 605         }
 606 };
 607
 608 static int __init i2c_adap_imx_init(void)
 609 {
 610         return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
 611 }
 612
 613 static void __exit i2c_adap_imx_exit(void)
 614 {
 615         platform_driver_unregister(&i2c_imx_driver);
 616 }
 617
 618 module_init(i2c_adap_imx_init);
 619 module_exit(i2c_adap_imx_exit);
 620
 621 MODULE_LICENSE("GPL");
 622 MODULE_AUTHOR("Darius Augulis");
 623 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
 624 MODULE_ALIAS("platform:" DRIVER_NAME);