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
  55 #include <mach/irqs.h>
  56 #include <mach/hardware.h>
  57 #include <mach/i2c.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 resource         *res;
 121         struct clk              *clk;
 122         void __iomem            *base;
 123         int                     irq;
 124         wait_queue_head_t       queue;
 125         unsigned long           i2csr;
 126         unsigned int            disable_delay;
 127         int                     stopped;
 128         unsigned int            ifdr; /* IMX_I2C_IFDR */
 129 };
 130
 131 static const struct of_device_id i2c_imx_dt_ids[] = {
 132         { .compatible = "fsl,imx1-i2c", },
 133         { /* sentinel */ }
 134 };
 135
 136 /** Functions for IMX I2C adapter driver ***************************************
 137 *******************************************************************************/
 138
 139 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 140 {
 141         unsigned long orig_jiffies = jiffies;
 142         unsigned int temp;
 143
 144         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 145
 146         while (1) {
 147                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 148                 if (for_busy && (temp & I2SR_IBB))
 149                         break;
 150                 if (!for_busy && !(temp & I2SR_IBB))
 151                         break;
 152                 if (signal_pending(current)) {
 153                         dev_dbg(&i2c_imx->adapter.dev,
 154                                 "<%s> I2C Interrupted\n", __func__);
 155                         return -EINTR;
 156                 }
 157                 if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
 158                         dev_dbg(&i2c_imx->adapter.dev,
 159                                 "<%s> I2C bus is busy\n", __func__);
 160                         return -ETIMEDOUT;
 161                 }
 162                 schedule();
 163         }
 164
 165         return 0;
 166 }
 167
 168 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
 169 {
 170         wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
 171
 172         if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
 173                 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
 174                 return -ETIMEDOUT;
 175         }
 176         dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
 177         i2c_imx->i2csr = 0;
 178         return 0;
 179 }
 180
 181 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
 182 {
 183         if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
 184                 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
 185                 return -EIO;  /* No ACK */
 186         }
 187
 188         dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
 189         return 0;
 190 }
 191
 192 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 193 {
 194         unsigned int temp = 0;
 195         int result;
 196
 197         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 198
 199         clk_enable(i2c_imx->clk);
 200         writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
 201         /* Enable I2C controller */
 202         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 203         writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
 204
 205         /* Wait controller to be stable */
 206         udelay(50);
 207
 208         /* Start I2C transaction */
 209         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 210         temp |= I2CR_MSTA;
 211         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 212         result = i2c_imx_bus_busy(i2c_imx, 1);
 213         if (result)
 214                 return result;
 215         i2c_imx->stopped = 0;
 216
 217         temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 218         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 219         return result;
 220 }
 221
 222 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 223 {
 224         unsigned int temp = 0;
 225
 226         if (!i2c_imx->stopped) {
 227                 /* Stop I2C transaction */
 228                 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 229                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 230                 temp &= ~(I2CR_MSTA | I2CR_MTX);
 231                 writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 232         }
 233         if (cpu_is_mx1()) {
 234                 /*
 235                  * This delay caused by an i.MXL hardware bug.
 236                  * If no (or too short) delay, no "STOP" bit will be generated.
 237                  */
 238                 udelay(i2c_imx->disable_delay);
 239         }
 240
 241         if (!i2c_imx->stopped) {
 242                 i2c_imx_bus_busy(i2c_imx, 0);
 243                 i2c_imx->stopped = 1;
 244         }
 245
 246         /* Disable I2C controller */
 247         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 248         clk_disable(i2c_imx->clk);
 249 }
 250
 251 static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
 252                                                         unsigned int rate)
 253 {
 254         unsigned int i2c_clk_rate;
 255         unsigned int div;
 256         int i;
 257
 258         /* Divider value calculation */
 259         i2c_clk_rate = clk_get_rate(i2c_imx->clk);
 260         div = (i2c_clk_rate + rate - 1) / rate;
 261         if (div < i2c_clk_div[0][0])
 262                 i = 0;
 263         else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
 264                 i = ARRAY_SIZE(i2c_clk_div) - 1;
 265         else
 266                 for (i = 0; i2c_clk_div[i][0] < div; i++);
 267
 268         /* Store divider value */
 269         i2c_imx->ifdr = i2c_clk_div[i][1];
 270
 271         /*
 272          * There dummy delay is calculated.
 273          * It should be about one I2C clock period long.
 274          * This delay is used in I2C bus disable function
 275          * to fix chip hardware bug.
 276          */
 277         i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
 278                 + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
 279
 280         /* dev_dbg() can't be used, because adapter is not yet registered */
 281 #ifdef CONFIG_I2C_DEBUG_BUS
 282         printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
 283                 __func__, i2c_clk_rate, div);
 284         printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
 285                 __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
 286 #endif
 287 }
 288
 289 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
 290 {
 291         struct imx_i2c_struct *i2c_imx = dev_id;
 292         unsigned int temp;
 293
 294         temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 295         if (temp & I2SR_IIF) {
 296                 /* save status register */
 297                 i2c_imx->i2csr = temp;
 298                 temp &= ~I2SR_IIF;
 299                 writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
 300                 wake_up(&i2c_imx->queue);
 301                 return IRQ_HANDLED;
 302         }
 303
 304         return IRQ_NONE;
 305 }
 306
 307 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 308 {
 309         int i, result;
 310
 311         dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
 312                 __func__, msgs->addr << 1);
 313
 314         /* write slave address */
 315         writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
 316         result = i2c_imx_trx_complete(i2c_imx);
 317         if (result)
 318                 return result;
 319         result = i2c_imx_acked(i2c_imx);
 320         if (result)
 321                 return result;
 322         dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
 323
 324         /* write data */
 325         for (i = 0; i < msgs->len; i++) {
 326                 dev_dbg(&i2c_imx->adapter.dev,
 327                         "<%s> write byte: B%d=0x%X\n",
 328                         __func__, i, msgs->buf[i]);
 329                 writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
 330                 result = i2c_imx_trx_complete(i2c_imx);
 331                 if (result)
 332                         return result;
 333                 result = i2c_imx_acked(i2c_imx);
 334                 if (result)
 335                         return result;
 336         }
 337         return 0;
 338 }
 339
 340 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 341 {
 342         int i, result;
 343         unsigned int temp;
 344
 345         dev_dbg(&i2c_imx->adapter.dev,
 346                 "<%s> write slave address: addr=0x%x\n",
 347                 __func__, (msgs->addr << 1) | 0x01);
 348
 349         /* write slave address */
 350         writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
 351         result = i2c_imx_trx_complete(i2c_imx);
 352         if (result)
 353                 return result;
 354         result = i2c_imx_acked(i2c_imx);
 355         if (result)
 356                 return result;
 357
 358         dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
 359
 360         /* setup bus to read data */
 361         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 362         temp &= ~I2CR_MTX;
 363         if (msgs->len - 1)
 364                 temp &= ~I2CR_TXAK;
 365         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 366         readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
 367
 368         dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
 369
 370         /* read data */
 371         for (i = 0; i < msgs->len; i++) {
 372                 result = i2c_imx_trx_complete(i2c_imx);
 373                 if (result)
 374                         return result;
 375                 if (i == (msgs->len - 1)) {
 376                         /* It must generate STOP before read I2DR to prevent
 377                            controller from generating another clock cycle */
 378                         dev_dbg(&i2c_imx->adapter.dev,
 379                                 "<%s> clear MSTA\n", __func__);
 380                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 381                         temp &= ~(I2CR_MSTA | I2CR_MTX);
 382                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 383                         i2c_imx_bus_busy(i2c_imx, 0);
 384                         i2c_imx->stopped = 1;
 385                 } else if (i == (msgs->len - 2)) {
 386                         dev_dbg(&i2c_imx->adapter.dev,
 387                                 "<%s> set TXAK\n", __func__);
 388                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 389                         temp |= I2CR_TXAK;
 390                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 391                 }
 392                 msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
 393                 dev_dbg(&i2c_imx->adapter.dev,
 394                         "<%s> read byte: B%d=0x%X\n",
 395                         __func__, i, msgs->buf[i]);
 396         }
 397         return 0;
 398 }
 399
 400 static int i2c_imx_xfer(struct i2c_adapter *adapter,
 401                                                 struct i2c_msg *msgs, int num)
 402 {
 403         unsigned int i, temp;
 404         int result;
 405         struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
 406
 407         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 408
 409         /* Start I2C transfer */
 410         result = i2c_imx_start(i2c_imx);
 411         if (result)
 412                 goto fail0;
 413
 414         /* read/write data */
 415         for (i = 0; i < num; i++) {
 416                 if (i) {
 417                         dev_dbg(&i2c_imx->adapter.dev,
 418                                 "<%s> repeated start\n", __func__);
 419                         temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 420                         temp |= I2CR_RSTA;
 421                         writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 422                         result =  i2c_imx_bus_busy(i2c_imx, 1);
 423                         if (result)
 424                                 goto fail0;
 425                 }
 426                 dev_dbg(&i2c_imx->adapter.dev,
 427                         "<%s> transfer message: %d\n", __func__, i);
 428                 /* write/read data */
 429 #ifdef CONFIG_I2C_DEBUG_BUS
 430                 temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 431                 dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
 432                         "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
 433                         (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
 434                         (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
 435                         (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
 436                 temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 437                 dev_dbg(&i2c_imx->adapter.dev,
 438                         "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
 439                         "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
 440                         (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
 441                         (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
 442                         (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
 443                         (temp & I2SR_RXAK ? 1 : 0));
 444 #endif
 445                 if (msgs[i].flags & I2C_M_RD)
 446                         result = i2c_imx_read(i2c_imx, &msgs[i]);
 447                 else
 448                         result = i2c_imx_write(i2c_imx, &msgs[i]);
 449                 if (result)
 450                         goto fail0;
 451         }
 452
 453 fail0:
 454         /* Stop I2C transfer */
 455         i2c_imx_stop(i2c_imx);
 456
 457         dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
 458                 (result < 0) ? "error" : "success msg",
 459                         (result < 0) ? result : num);
 460         return (result < 0) ? result : num;
 461 }
 462
 463 static u32 i2c_imx_func(struct i2c_adapter *adapter)
 464 {
 465         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 466 }
 467
 468 static struct i2c_algorithm i2c_imx_algo = {
 469         .master_xfer    = i2c_imx_xfer,
 470         .functionality  = i2c_imx_func,
 471 };
 472
 473 static int __init i2c_imx_probe(struct platform_device *pdev)
 474 {
 475         struct imx_i2c_struct *i2c_imx;
 476         struct resource *res;
 477         struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
 478         void __iomem *base;
 479         resource_size_t res_size;
 480         int irq, bitrate;
 481         int ret;
 482
 483         dev_dbg(&pdev->dev, "<%s>\n", __func__);
 484
 485         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 486         if (!res) {
 487                 dev_err(&pdev->dev, "can't get device resources\n");
 488                 return -ENOENT;
 489         }
 490         irq = platform_get_irq(pdev, 0);
 491         if (irq < 0) {
 492                 dev_err(&pdev->dev, "can't get irq number\n");
 493                 return -ENOENT;
 494         }
 495
 496         res_size = resource_size(res);
 497
 498         if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
 499                 dev_err(&pdev->dev, "request_mem_region failed\n");
 500                 return -EBUSY;
 501         }
 502
 503         base = ioremap(res->start, res_size);
 504         if (!base) {
 505                 dev_err(&pdev->dev, "ioremap failed\n");
 506                 ret = -EIO;
 507                 goto fail1;
 508         }
 509
 510         i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
 511         if (!i2c_imx) {
 512                 dev_err(&pdev->dev, "can't allocate interface\n");
 513                 ret = -ENOMEM;
 514                 goto fail2;
 515         }
 516
 517         /* Setup i2c_imx driver structure */
 518         strcpy(i2c_imx->adapter.name, pdev->name);
 519         i2c_imx->adapter.owner          = THIS_MODULE;
 520         i2c_imx->adapter.algo           = &i2c_imx_algo;
 521         i2c_imx->adapter.dev.parent     = &pdev->dev;
 522         i2c_imx->adapter.nr             = pdev->id;
 523         i2c_imx->adapter.dev.of_node    = pdev->dev.of_node;
 524         i2c_imx->irq                    = irq;
 525         i2c_imx->base                   = base;
 526         i2c_imx->res                    = res;
 527
 528         /* Get I2C clock */
 529         i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
 530         if (IS_ERR(i2c_imx->clk)) {
 531                 ret = PTR_ERR(i2c_imx->clk);
 532                 dev_err(&pdev->dev, "can't get I2C clock\n");
 533                 goto fail3;
 534         }
 535
 536         /* Request IRQ */
 537         ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
 538         if (ret) {
 539                 dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
 540                 goto fail4;
 541         }
 542
 543         /* Init queue */
 544         init_waitqueue_head(&i2c_imx->queue);
 545
 546         /* Set up adapter data */
 547         i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
 548
 549         /* Set up clock divider */
 550         bitrate = IMX_I2C_BIT_RATE;
 551         ret = of_property_read_u32(pdev->dev.of_node,
 552                                    "clock-frequency", &bitrate);
 553         if (ret < 0 && pdata && pdata->bitrate)
 554                 bitrate = pdata->bitrate;
 555         i2c_imx_set_clk(i2c_imx, bitrate);
 556
 557         /* Set up chip registers to defaults */
 558         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 559         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 560
 561         /* Add I2C adapter */
 562         ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
 563         if (ret < 0) {
 564                 dev_err(&pdev->dev, "registration failed\n");
 565                 goto fail5;
 566         }
 567
 568         of_i2c_register_devices(&i2c_imx->adapter);
 569
 570         /* Set up platform driver data */
 571         platform_set_drvdata(pdev, i2c_imx);
 572
 573         dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
 574         dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
 575                 i2c_imx->res->start, i2c_imx->res->end);
 576         dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
 577                 res_size, i2c_imx->res->start);
 578         dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
 579                 i2c_imx->adapter.name);
 580         dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
 581
 582         return 0;   /* Return OK */
 583
 584 fail5:
 585         free_irq(i2c_imx->irq, i2c_imx);
 586 fail4:
 587         clk_put(i2c_imx->clk);
 588 fail3:
 589         kfree(i2c_imx);
 590 fail2:
 591         iounmap(base);
 592 fail1:
 593         release_mem_region(res->start, resource_size(res));
 594         return ret; /* Return error number */
 595 }
 596
 597 static int __exit i2c_imx_remove(struct platform_device *pdev)
 598 {
 599         struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
 600
 601         /* remove adapter */
 602         dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
 603         i2c_del_adapter(&i2c_imx->adapter);
 604         platform_set_drvdata(pdev, NULL);
 605
 606         /* free interrupt */
 607         free_irq(i2c_imx->irq, i2c_imx);
 608
 609         /* setup chip registers to defaults */
 610         writeb(0, i2c_imx->base + IMX_I2C_IADR);
 611         writeb(0, i2c_imx->base + IMX_I2C_IFDR);
 612         writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 613         writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 614
 615         clk_put(i2c_imx->clk);
 616
 617         iounmap(i2c_imx->base);
 618         release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
 619         kfree(i2c_imx);
 620         return 0;
 621 }
 622
 623 static struct platform_driver i2c_imx_driver = {
 624         .remove         = __exit_p(i2c_imx_remove),
 625         .driver = {
 626                 .name   = DRIVER_NAME,
 627                 .owner  = THIS_MODULE,
 628                 .of_match_table = i2c_imx_dt_ids,
 629         }
 630 };
 631
 632 static int __init i2c_adap_imx_init(void)
 633 {
 634         return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
 635 }
 636 subsys_initcall(i2c_adap_imx_init);
 637
 638 static void __exit i2c_adap_imx_exit(void)
 639 {
 640         platform_driver_unregister(&i2c_imx_driver);
 641 }
 642 module_exit(i2c_adap_imx_exit);
 643
 644 MODULE_LICENSE("GPL");
 645 MODULE_AUTHOR("Darius Augulis");
 646 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
 647 MODULE_ALIAS("platform:" DRIVER_NAME);