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 #include <linux/of.h>
  52 #include <linux/of_device.h>
  53 #include <linux/of_i2c.h>
  54 #include <linux/pinctrl/consumer.h>
  55
  56 #include <mach/hardware.h>
  57 #include <linux/platform_data/i2c-imx.h>
  58
  59 /** Defines ********************************************************************
  60 *******************************************************************************/
  61
  62 /* This will be the driver name the kernel reports */
  63 #define DRIVER_NAME "imx-i2c"
  64
  65 /* Default value */
  66 #define IMX_I2C_BIT_RATE        100000  /* 100kHz */
  67
  68 /* IMX I2C registers */
  69 #define IMX_I2C_IADR    0x00    /* i2c slave address */
  70 #define IMX_I2C_IFDR    0x04    /* i2c frequency divider */
  71 #define IMX_I2C_I2CR    0x08    /* i2c control */
  72 #define IMX_I2C_I2SR    0x0C    /* i2c status */
  73 #define IMX_I2C_I2DR    0x10    /* i2c transfer data */
  74
  75 /* Bits of IMX I2C registers */
  76 #define I2SR_RXAK       0x01
  77 #define I2SR_IIF        0x02
  78 #define I2SR_SRW        0x04
  79 #define I2SR_IAL        0x10
  80 #define I2SR_IBB        0x20
  81 #define I2SR_IAAS       0x40
  82 #define I2SR_ICF        0x80
  83 #define I2CR_RSTA       0x04
  84 #define I2CR_TXAK       0x08
  85 #define I2CR_MTX        0x10
  86 #define I2CR_MSTA       0x20
  87 #define I2CR_IIEN       0x40
  88 #define I2CR_IEN        0x80
  89
  90 /** Variables ******************************************************************
  91 *******************************************************************************/
  92
  93 /*
  94  * sorted list of clock divider, register value pairs
  95  * taken from table 26-5, p.26-9, Freescale i.MX
  96  * Integrated Portable System Processor Reference Manual
  97  * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
  98  *
  99  * Duplicated divider values removed from list
 100  */
 101
 102 static u16 __initdata i2c_clk_div[50][2] = {
 103         { 22,   0x20 }, { 24,   0x21 }, { 26,   0x22 }, { 28,   0x23 },
 104         { 30,   0x00 }, { 32,   0x24 }, { 36,   0x25 }, { 40,   0x26 },
 105         { 42,   0x03 }, { 44,   0x27 }, { 48,   0x28 }, { 52,   0x05 },
 106         { 56,   0x29 }, { 60,   0x06 }, { 64,   0x2A }, { 72,   0x2B },
 107         { 80,   0x2C }, { 88,   0x09 }, { 96,   0x2D }, { 104,  0x0A },
 108         { 112,  0x2E }, { 128,  0x2F }, { 144,  0x0C }, { 160,  0x30 },
 109         { 192,  0x31 }, { 224,  0x32 }, { 240,  0x0F }, { 256,  0x33 },
 110         { 288,  0x10 }, { 320,  0x34 }, { 384,  0x35 }, { 448,  0x36 },
 111         { 480,  0x13 }, { 512,  0x37 }, { 576,  0x14 }, { 640,  0x38 },
 112         { 768,  0x39 }, { 896,  0x3A }, { 960,  0x17 }, { 1024, 0x3B },
 113         { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
 114         { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
 115         { 3072, 0x1E }, { 3840, 0x1F }
 116 };
 117
 118 struct imx_i2c_struct {
 119         struct i2c_adapter      adapter;
 120         struct clk              *clk;
 121         void __iomem            *base;
 122         wait_queue_head_t       queue;
 123         unsigned long           i2csr;
 124         unsigned int            disable_delay;
 125         int                     stopped;
 126         unsigned int            ifdr; /* IMX_I2C_IFDR */
 127 };
 128
 129 static const struct of_device_id i2c_imx_dt_ids[] = {
 130         { .compatible = "fsl,imx1-i2c", },
 131         { /* sentinel */ }
 132 };
 133
 134 /** Functions for IMX I2C adapter driver ***************************************
 135 *******************************************************************************/
 136
 137 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 138 {
 139         unsigned long orig_jiffies = jiffies;
 140         unsigned int temp;
 141
 142         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 143
 144         while (1) {
 145                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 146                 if (for_busy && (temp & I2SR_IBB))
 147                         break;
 148                 if (!for_busy && !(temp & I2SR_IBB))
 149                         break;
 150                 if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
 151                         dev_dbg(&i2c_imx->adapter.dev,
 152                                 "<%s> I2C bus is busy\n", __func__);
 153                         return -ETIMEDOUT;
 154                 }
 155                 schedule();
 156         }
 157
 158         return 0;
 159 }
 160
 161 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
 162 {
 163         wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
 164
 165         if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
 166                 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
 167                 return -ETIMEDOUT;
 168         }
 169         dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
 170         i2c_imx->i2csr = 0;
 171         return 0;
 172 }
 173
 174 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
 175 {
 176         if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
 177                 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
 178                 return -EIO;  /* No ACK */
 179         }
 180
 181         dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
 182         return 0;
 183 }
 184
 185 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 186 {
 187         unsigned int temp = 0;
 188         int result;
 189
 190         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 191
 192         clk_prepare_enable(i2c_imx->clk);
 193         writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
 194         /* Enable I2C controller */
 195         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 196         writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
 197
 198         /* Wait controller to be stable */
 199         udelay(50);
 200
 201         /* Start I2C transaction */
 202         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 203         temp |= I2CR_MSTA;
 204         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 205         result = i2c_imx_bus_busy(i2c_imx, 1);
 206         if (result)
 207                 return result;
 208         i2c_imx->stopped = 0;
 209
 210         temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 211         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 212         return result;
 213 }
 214
 215 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 216 {
 217         unsigned int temp = 0;
 218
 219         if (!i2c_imx->stopped) {
 220                 /* Stop I2C transaction */
 221                 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 222                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 223                 temp &= ~(I2CR_MSTA | I2CR_MTX);
 224                 writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 225         }
 226         if (cpu_is_mx1()) {
 227                 /*
 228                  * This delay caused by an i.MXL hardware bug.
 229                  * If no (or too short) delay, no "STOP" bit will be generated.
 230                  */
 231                 udelay(i2c_imx->disable_delay);
 232         }
 233
 234         if (!i2c_imx->stopped) {
 235                 i2c_imx_bus_busy(i2c_imx, 0);
 236                 i2c_imx->stopped = 1;
 237         }
 238
 239         /* Disable I2C controller */
 240         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 241         clk_disable_unprepare(i2c_imx->clk);
 242 }
 243
 244 static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
 245                                                         unsigned int rate)
 246 {
 247         unsigned int i2c_clk_rate;
 248         unsigned int div;
 249         int i;
 250
 251         /* Divider value calculation */
 252         i2c_clk_rate = clk_get_rate(i2c_imx->clk);
 253         div = (i2c_clk_rate + rate - 1) / rate;
 254         if (div < i2c_clk_div[0][0])
 255                 i = 0;
 256         else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
 257                 i = ARRAY_SIZE(i2c_clk_div) - 1;
 258         else
 259                 for (i = 0; i2c_clk_div[i][0] < div; i++);
 260
 261         /* Store divider value */
 262         i2c_imx->ifdr = i2c_clk_div[i][1];
 263
 264         /*
 265          * There dummy delay is calculated.
 266          * It should be about one I2C clock period long.
 267          * This delay is used in I2C bus disable function
 268          * to fix chip hardware bug.
 269          */
 270         i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
 271                 + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
 272
 273         /* dev_dbg() can't be used, because adapter is not yet registered */
 274 #ifdef CONFIG_I2C_DEBUG_BUS
 275         printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
 276                 __func__, i2c_clk_rate, div);
 277         printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
 278                 __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
 279 #endif
 280 }
 281
 282 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
 283 {
 284         struct imx_i2c_struct *i2c_imx = dev_id;
 285         unsigned int temp;
 286
 287         temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 288         if (temp & I2SR_IIF) {
 289                 /* save status register */
 290                 i2c_imx->i2csr = temp;
 291                 temp &= ~I2SR_IIF;
 292                 writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
 293                 wake_up(&i2c_imx->queue);
 294                 return IRQ_HANDLED;
 295         }
 296
 297         return IRQ_NONE;
 298 }
 299
 300 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 301 {
 302         int i, result;
 303
 304         dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
 305                 __func__, msgs->addr << 1);
 306
 307         /* write slave address */
 308         writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
 309         result = i2c_imx_trx_complete(i2c_imx);
 310         if (result)
 311                 return result;
 312         result = i2c_imx_acked(i2c_imx);
 313         if (result)
 314                 return result;
 315         dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
 316
 317         /* write data */
 318         for (i = 0; i < msgs->len; i++) {
 319                 dev_dbg(&i2c_imx->adapter.dev,
 320                         "<%s> write byte: B%d=0x%X\n",
 321                         __func__, i, msgs->buf[i]);
 322                 writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
 323                 result = i2c_imx_trx_complete(i2c_imx);
 324                 if (result)
 325                         return result;
 326                 result = i2c_imx_acked(i2c_imx);
 327                 if (result)
 328                         return result;
 329         }
 330         return 0;
 331 }
 332
 333 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 334 {
 335         int i, result;
 336         unsigned int temp;
 337
 338         dev_dbg(&i2c_imx->adapter.dev,
 339                 "<%s> write slave address: addr=0x%x\n",
 340                 __func__, (msgs->addr << 1) | 0x01);
 341
 342         /* write slave address */
 343         writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
 344         result = i2c_imx_trx_complete(i2c_imx);
 345         if (result)
 346                 return result;
 347         result = i2c_imx_acked(i2c_imx);
 348         if (result)
 349                 return result;
 350
 351         dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
 352
 353         /* setup bus to read data */
 354         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 355         temp &= ~I2CR_MTX;
 356         if (msgs->len - 1)
 357                 temp &= ~I2CR_TXAK;
 358         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 359         readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
 360
 361         dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
 362
 363         /* read data */
 364         for (i = 0; i < msgs->len; i++) {
 365                 result = i2c_imx_trx_complete(i2c_imx);
 366                 if (result)
 367                         return result;
 368                 if (i == (msgs->len - 1)) {
 369                         /* It must generate STOP before read I2DR to prevent
 370                            controller from generating another clock cycle */
 371                         dev_dbg(&i2c_imx->adapter.dev,
 372                                 "<%s> clear MSTA\n", __func__);
 373                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 374                         temp &= ~(I2CR_MSTA | I2CR_MTX);
 375                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 376                         i2c_imx_bus_busy(i2c_imx, 0);
 377                         i2c_imx->stopped = 1;
 378                 } else if (i == (msgs->len - 2)) {
 379                         dev_dbg(&i2c_imx->adapter.dev,
 380                                 "<%s> set TXAK\n", __func__);
 381                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 382                         temp |= I2CR_TXAK;
 383                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 384                 }
 385                 msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
 386                 dev_dbg(&i2c_imx->adapter.dev,
 387                         "<%s> read byte: B%d=0x%X\n",
 388                         __func__, i, msgs->buf[i]);
 389         }
 390         return 0;
 391 }
 392
 393 static int i2c_imx_xfer(struct i2c_adapter *adapter,
 394                                                 struct i2c_msg *msgs, int num)
 395 {
 396         unsigned int i, temp;
 397         int result;
 398         struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
 399
 400         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 401
 402         /* Start I2C transfer */
 403         result = i2c_imx_start(i2c_imx);
 404         if (result)
 405                 goto fail0;
 406
 407         /* read/write data */
 408         for (i = 0; i < num; i++) {
 409                 if (i) {
 410                         dev_dbg(&i2c_imx->adapter.dev,
 411                                 "<%s> repeated start\n", __func__);
 412                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 413                         temp |= I2CR_RSTA;
 414                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 415                         result =  i2c_imx_bus_busy(i2c_imx, 1);
 416                         if (result)
 417                                 goto fail0;
 418                 }
 419                 dev_dbg(&i2c_imx->adapter.dev,
 420                         "<%s> transfer message: %d\n", __func__, i);
 421                 /* write/read data */
 422 #ifdef CONFIG_I2C_DEBUG_BUS
 423                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 424                 dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
 425                         "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
 426                         (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
 427                         (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
 428                         (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
 429                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 430                 dev_dbg(&i2c_imx->adapter.dev,
 431                         "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
 432                         "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
 433                         (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
 434                         (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
 435                         (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
 436                         (temp & I2SR_RXAK ? 1 : 0));
 437 #endif
 438                 if (msgs[i].flags & I2C_M_RD)
 439                         result = i2c_imx_read(i2c_imx, &msgs[i]);
 440                 else
 441                         result = i2c_imx_write(i2c_imx, &msgs[i]);
 442                 if (result)
 443                         goto fail0;
 444         }
 445
 446 fail0:
 447         /* Stop I2C transfer */
 448         i2c_imx_stop(i2c_imx);
 449
 450         dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
 451                 (result < 0) ? "error" : "success msg",
 452                         (result < 0) ? result : num);
 453         return (result < 0) ? result : num;
 454 }
 455
 456 static u32 i2c_imx_func(struct i2c_adapter *adapter)
 457 {
 458         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 459 }
 460
 461 static struct i2c_algorithm i2c_imx_algo = {
 462         .master_xfer    = i2c_imx_xfer,
 463         .functionality  = i2c_imx_func,
 464 };
 465
 466 static int __init i2c_imx_probe(struct platform_device *pdev)
 467 {
 468         struct imx_i2c_struct *i2c_imx;
 469         struct resource *res;
 470         struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
 471         struct pinctrl *pinctrl;
 472         void __iomem *base;
 473         int irq, ret;
 474         u32 bitrate;
 475
 476         dev_dbg(&pdev->dev, "<%s>\n", __func__);
 477
 478         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 479         if (!res) {
 480                 dev_err(&pdev->dev, "can't get device resources\n");
 481                 return -ENOENT;
 482         }
 483         irq = platform_get_irq(pdev, 0);
 484         if (irq < 0) {
 485                 dev_err(&pdev->dev, "can't get irq number\n");
 486                 return -ENOENT;
 487         }
 488
 489         base = devm_request_and_ioremap(&pdev->dev, res);
 490         if (!base)
 491                 return -EBUSY;
 492
 493         i2c_imx = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_struct),
 494                                 GFP_KERNEL);
 495         if (!i2c_imx) {
 496                 dev_err(&pdev->dev, "can't allocate interface\n");
 497                 return -ENOMEM;
 498         }
 499
 500         /* Setup i2c_imx driver structure */
 501         strlcpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
 502         i2c_imx->adapter.owner          = THIS_MODULE;
 503         i2c_imx->adapter.algo           = &i2c_imx_algo;
 504         i2c_imx->adapter.dev.parent     = &pdev->dev;
 505         i2c_imx->adapter.nr             = pdev->id;
 506         i2c_imx->adapter.dev.of_node    = pdev->dev.of_node;
 507         i2c_imx->base                   = base;
 508
 509         pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
 510         if (IS_ERR(pinctrl)) {
 511                 dev_err(&pdev->dev, "can't get/select pinctrl\n");
 512                 return PTR_ERR(pinctrl);
 513         }
 514
 515         /* Get I2C clock */
 516         i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
 517         if (IS_ERR(i2c_imx->clk)) {
 518                 dev_err(&pdev->dev, "can't get I2C clock\n");
 519                 return PTR_ERR(i2c_imx->clk);
 520         }
 521
 522         /* Request IRQ */
 523         ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, 0,
 524                                 pdev->name, i2c_imx);
 525         if (ret) {
 526                 dev_err(&pdev->dev, "can't claim irq %d\n", irq);
 527                 return ret;
 528         }
 529
 530         /* Init queue */
 531         init_waitqueue_head(&i2c_imx->queue);
 532
 533         /* Set up adapter data */
 534         i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
 535
 536         /* Set up clock divider */
 537         bitrate = IMX_I2C_BIT_RATE;
 538         ret = of_property_read_u32(pdev->dev.of_node,
 539                                    "clock-frequency", &bitrate);
 540         if (ret < 0 && pdata && pdata->bitrate)
 541                 bitrate = pdata->bitrate;
 542         i2c_imx_set_clk(i2c_imx, bitrate);
 543
 544         /* Set up chip registers to defaults */
 545         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 546         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 547
 548         /* Add I2C adapter */
 549         ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
 550         if (ret < 0) {
 551                 dev_err(&pdev->dev, "registration failed\n");
 552                 return ret;
 553         }
 554
 555         of_i2c_register_devices(&i2c_imx->adapter);
 556
 557         /* Set up platform driver data */
 558         platform_set_drvdata(pdev, i2c_imx);
 559
 560         dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
 561         dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
 562                 res->start, res->end);
 563         dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x\n",
 564                 resource_size(res), res->start);
 565         dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
 566                 i2c_imx->adapter.name);
 567         dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
 568
 569         return 0;   /* Return OK */
 570 }
 571
 572 static int __exit i2c_imx_remove(struct platform_device *pdev)
 573 {
 574         struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
 575
 576         /* remove adapter */
 577         dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
 578         i2c_del_adapter(&i2c_imx->adapter);
 579         platform_set_drvdata(pdev, NULL);
 580
 581         /* setup chip registers to defaults */
 582         writeb(0, i2c_imx->base + IMX_I2C_IADR);
 583         writeb(0, i2c_imx->base + IMX_I2C_IFDR);
 584         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 585         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 586
 587         return 0;
 588 }
 589
 590 static struct platform_driver i2c_imx_driver = {
 591         .remove         = __exit_p(i2c_imx_remove),
 592         .driver = {
 593                 .name   = DRIVER_NAME,
 594                 .owner  = THIS_MODULE,
 595                 .of_match_table = i2c_imx_dt_ids,
 596         }
 597 };
 598
 599 static int __init i2c_adap_imx_init(void)
 600 {
 601         return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
 602 }
 603 subsys_initcall(i2c_adap_imx_init);
 604
 605 static void __exit i2c_adap_imx_exit(void)
 606 {
 607         platform_driver_unregister(&i2c_imx_driver);
 608 }
 609 module_exit(i2c_adap_imx_exit);
 610
 611 MODULE_LICENSE("GPL");
 612 MODULE_AUTHOR("Darius Augulis");
 613 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
 614 MODULE_ALIAS("platform:" DRIVER_NAME);