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