LXR linux/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
  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
  98static 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
 114struct 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        unsigned int            ifdr; /* IMX_I2C_IFDR */
 125};
 126
 127/** Functions for IMX I2C adapter driver ***************************************
 128*******************************************************************************/
 129
 130static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 131{
 132        unsigned long orig_jiffies = jiffies;
 133        unsigned int temp;
 134
 135        dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 136
 137        while (1) {
 138                temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 139                if (for_busy && (temp & I2SR_IBB))
 140                        break;
 141                if (!for_busy && !(temp & I2SR_IBB))
 142                        break;
 143                if (signal_pending(current)) {
 144                        dev_dbg(&i2c_imx->adapter.dev,
 145                                "<%s> I2C Interrupted\n", __func__);
 146                        return -EINTR;
 147                }
 148                if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
 149                        dev_dbg(&i2c_imx->adapter.dev,
 150                                "<%s> I2C bus is busy\n", __func__);
 151                        return -EIO;
 152                }
 153                schedule();
 154        }
 155
 156        return 0;
 157}
 158
 159static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
 160{
 161        int result;
 162
 163        result = wait_event_interruptible_timeout(i2c_imx->queue,
 164                i2c_imx->i2csr & I2SR_IIF, HZ / 10);
 165
 166        if (unlikely(result < 0)) {
 167                dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__);
 168                return result;
 169        } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
 170                dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
 171                return -ETIMEDOUT;
 172        }
 173        dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
 174        i2c_imx->i2csr = 0;
 175        return 0;
 176}
 177
 178static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
 179{
 180        if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
 181                dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
 182                return -EIO;  /* No ACK */
 183        }
 184
 185        dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
 186        return 0;
 187}
 188
 189static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 190{
 191        unsigned int temp = 0;
 192        int result;
 193
 194        dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 195
 196        clk_enable(i2c_imx->clk);
 197        writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
 198        /* Enable I2C controller */
 199        writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 200        writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
 201
 202        /* Wait controller to be stable */
 203        udelay(50);
 204
 205        /* Start I2C transaction */
 206        temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 207        temp |= I2CR_MSTA;
 208        writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 209        result = i2c_imx_bus_busy(i2c_imx, 1);
 210        if (result)
 211                return result;
 212        i2c_imx->stopped = 0;
 213
 214        temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 215        writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 216        return result;
 217}
 218
 219static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 220{
 221        unsigned int temp = 0;
 222
 223        if (!i2c_imx->stopped) {
 224                /* Stop I2C transaction */
 225                dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 226                temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 227                temp &= ~(I2CR_MSTA | I2CR_MTX);
 228                writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 229                i2c_imx->stopped = 1;
 230        }
 231        if (cpu_is_mx1()) {
 232                /*
 233                 * This delay caused by an i.MXL hardware bug.
 234                 * If no (or too short) delay, no "STOP" bit will be generated.
 235                 */
 236                udelay(i2c_imx->disable_delay);
 237        }
 238
 239        if (!i2c_imx->stopped)
 240                i2c_imx_bus_busy(i2c_imx, 0);
 241
 242        /* Disable I2C controller */
 243        writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 244        clk_disable(i2c_imx->clk);
 245}
 246
 247static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
 248                                                        unsigned int rate)
 249{
 250        unsigned int i2c_clk_rate;
 251        unsigned int div;
 252        int i;
 253
 254        /* Divider value calculation */
 255        i2c_clk_rate = clk_get_rate(i2c_imx->clk);
 256        div = (i2c_clk_rate + rate - 1) / rate;
 257        if (div < i2c_clk_div[0][0])
 258                i = 0;
 259        else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
 260                i = ARRAY_SIZE(i2c_clk_div) - 1;
 261        else
 262                for (i = 0; i2c_clk_div[i][0] < div; i++);
 263
 264        /* Store divider value */
 265        i2c_imx->ifdr = i2c_clk_div[i][1];
 266
 267        /*
 268         * There dummy delay is calculated.
 269         * It should be about one I2C clock period long.
 270         * This delay is used in I2C bus disable function
 271         * to fix chip hardware bug.
 272         */
 273        i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
 274                + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
 275
 276        /* dev_dbg() can't be used, because adapter is not yet registered */
 277#ifdef CONFIG_I2C_DEBUG_BUS
 278        printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
 279                __func__, i2c_clk_rate, div);
 280        printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
 281                __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
 282#endif
 283}
 284
 285static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
 286{
 287        struct imx_i2c_struct *i2c_imx = dev_id;
 288        unsigned int temp;
 289
 290        temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 291        if (temp & I2SR_IIF) {
 292                /* save status register */
 293                i2c_imx->i2csr = temp;
 294                temp &= ~I2SR_IIF;
 295                writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
 296                wake_up_interruptible(&i2c_imx->queue);
 297                return IRQ_HANDLED;
 298        }
 299
 300        return IRQ_NONE;
 301}
 302
 303static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 304{
 305        int i, result;
 306
 307        dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
 308                __func__, msgs->addr << 1);
 309
 310        /* write slave address */
 311        writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
 312        result = i2c_imx_trx_complete(i2c_imx);
 313        if (result)
 314                return result;
 315        result = i2c_imx_acked(i2c_imx);
 316        if (result)
 317                return result;
 318        dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
 319
 320        /* write data */
 321        for (i = 0; i < msgs->len; i++) {
 322                dev_dbg(&i2c_imx->adapter.dev,
 323                        "<%s> write byte: B%d=0x%X\n",
 324                        __func__, i, msgs->buf[i]);
 325                writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
 326                result = i2c_imx_trx_complete(i2c_imx);
 327                if (result)
 328                        return result;
 329                result = i2c_imx_acked(i2c_imx);
 330                if (result)
 331                        return result;
 332        }
 333        return 0;
 334}
 335
 336static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 337{
 338        int i, result;
 339        unsigned int temp;
 340
 341        dev_dbg(&i2c_imx->adapter.dev,
 342                "<%s> write slave address: addr=0x%x\n",
 343                __func__, (msgs->addr << 1) | 0x01);
 344
 345        /* write slave address */
 346        writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
 347        result = i2c_imx_trx_complete(i2c_imx);
 348        if (result)
 349                return result;
 350        result = i2c_imx_acked(i2c_imx);
 351        if (result)
 352                return result;
 353
 354        dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
 355
 356        /* setup bus to read data */
 357        temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 358        temp &= ~I2CR_MTX;
 359        if (msgs->len - 1)
 360                temp &= ~I2CR_TXAK;
 361        writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 362        readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
 363
 364        dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
 365
 366        /* read data */
 367        for (i = 0; i < msgs->len; i++) {
 368                result = i2c_imx_trx_complete(i2c_imx);
 369                if (result)
 370                        return result;
 371                if (i == (msgs->len - 1)) {
 372                        /* It must generate STOP before read I2DR to prevent
 373                           controller from generating another clock cycle */
 374                        dev_dbg(&i2c_imx->adapter.dev,
 375                                "<%s> clear MSTA\n", __func__);
 376                        temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 377                        temp &= ~(I2CR_MSTA | I2CR_MTX);
 378                        writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 379                        i2c_imx_bus_busy(i2c_imx, 0);
 380                        i2c_imx->stopped = 1;
 381                } else if (i == (msgs->len - 2)) {
 382                        dev_dbg(&i2c_imx->adapter.dev,
 383                                "<%s> set TXAK\n", __func__);
 384                        temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 385                        temp |= I2CR_TXAK;
 386                        writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 387                }
 388                msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
 389                dev_dbg(&i2c_imx->adapter.dev,
 390                        "<%s> read byte: B%d=0x%X\n",
 391                        __func__, i, msgs->buf[i]);
 392        }
 393        return 0;
 394}
 395
 396static int i2c_imx_xfer(struct i2c_adapter *adapter,
 397                                                struct i2c_msg *msgs, int num)
 398{
 399        unsigned int i, temp;
 400        int result;
 401        struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
 402
 403        dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 404
 405        /* Start I2C transfer */
 406        result = i2c_imx_start(i2c_imx);
 407        if (result)
 408                goto fail0;
 409
 410        /* read/write data */
 411        for (i = 0; i < num; i++) {
 412                if (i) {
 413                        dev_dbg(&i2c_imx->adapter.dev,
 414                                "<%s> repeated start\n", __func__);
 415                        temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 416                        temp |= I2CR_RSTA;
 417                        writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 418                        result =  i2c_imx_bus_busy(i2c_imx, 1);
 419                        if (result)
 420                                goto fail0;
 421                }
 422                dev_dbg(&i2c_imx->adapter.dev,
 423                        "<%s> transfer message: %d\n", __func__, i);
 424                /* write/read data */
 425#ifdef CONFIG_I2C_DEBUG_BUS
 426                temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 427                dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
 428                        "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
 429                        (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
 430                        (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
 431                        (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
 432                temp = readb(i2c_imx->base + IMX_I2C_I2SR);
 433                dev_dbg(&i2c_imx->adapter.dev,
 434                        "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
 435                        "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
 436                        (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
 437                        (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
 438                        (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
 439                        (temp & I2SR_RXAK ? 1 : 0));
 440#endif
 441                if (msgs[i].flags & I2C_M_RD)
 442                        result = i2c_imx_read(i2c_imx, &msgs[i]);
 443                else
 444                        result = i2c_imx_write(i2c_imx, &msgs[i]);
 445        }
 446
 447fail0:
 448        /* Stop I2C transfer */
 449        i2c_imx_stop(i2c_imx);
 450
 451        dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
 452                (result < 0) ? "error" : "success msg",
 453                        (result < 0) ? result : num);
 454        return (result < 0) ? result : num;
 455}
 456
 457static u32 i2c_imx_func(struct i2c_adapter *adapter)
 458{
 459        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 460}
 461
 462static struct i2c_algorithm i2c_imx_algo = {
 463        .master_xfer    = i2c_imx_xfer,
 464        .functionality  = i2c_imx_func,
 465};
 466
 467static int __init i2c_imx_probe(struct platform_device *pdev)
 468{
 469        struct imx_i2c_struct *i2c_imx;
 470        struct resource *res;
 471        struct imxi2c_platform_data *pdata;
 472        void __iomem *base;
 473        resource_size_t res_size;
 474        int irq;
 475        int ret;
 476
 477        dev_dbg(&pdev->dev, "<%s>\n", __func__);
 478
 479        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 480        if (!res) {
 481                dev_err(&pdev->dev, "can't get device resources\n");
 482                return -ENOENT;
 483        }
 484        irq = platform_get_irq(pdev, 0);
 485        if (irq < 0) {
 486                dev_err(&pdev->dev, "can't get irq number\n");
 487                return -ENOENT;
 488        }
 489
 490        pdata = pdev->dev.platform_data;
 491
 492        if (pdata && pdata->init) {
 493                ret = pdata->init(&pdev->dev);
 494                if (ret)
 495                        return ret;
 496        }
 497
 498        res_size = resource_size(res);
 499        base = ioremap(res->start, res_size);
 500        if (!base) {
 501                dev_err(&pdev->dev, "ioremap failed\n");
 502                ret = -EIO;
 503                goto fail0;
 504        }
 505
 506        i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
 507        if (!i2c_imx) {
 508                dev_err(&pdev->dev, "can't allocate interface\n");
 509                ret = -ENOMEM;
 510                goto fail1;
 511        }
 512
 513        if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
 514                ret = -EBUSY;
 515                goto fail2;
 516        }
 517
 518        /* Setup i2c_imx driver structure */
 519        strcpy(i2c_imx->adapter.name, pdev->name);
 520        i2c_imx->adapter.owner          = THIS_MODULE;
 521        i2c_imx->adapter.algo           = &i2c_imx_algo;
 522        i2c_imx->adapter.dev.parent     = &pdev->dev;
 523        i2c_imx->adapter.nr             = pdev->id;
 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        if (pdata && pdata->bitrate)
 551                i2c_imx_set_clk(i2c_imx, pdata->bitrate);
 552        else
 553                i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
 554
 555        /* Set up chip registers to defaults */
 556        writeb(0, i2c_imx->base + IMX_I2C_I2CR);
 557        writeb(0, i2c_imx->base + IMX_I2C_I2SR);
 558
 559        /* Add I2C adapter */
 560        ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
 561        if (ret < 0) {
 562                dev_err(&pdev->dev, "registration failed\n");
 563                goto fail5;
 564        }
 565
 566        /* Set up platform driver data */
 567        platform_set_drvdata(pdev, i2c_imx);
 568
 569        dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
 570        dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
 571                i2c_imx->res->start, i2c_imx->res->end);
 572        dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
 573                res_size, i2c_imx->res->start);
 574        dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
 575                i2c_imx->adapter.name);
 576        dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
 577
 578        return 0;   /* Return OK */
 579
 580fail5:
 581        free_irq(i2c_imx->irq, i2c_imx);
 582fail4:
 583        clk_put(i2c_imx->clk);
 584fail3:
 585        release_mem_region(i2c_imx->res->start, resource_size(res));
 586fail2:
 587        kfree(i2c_imx);
 588fail1:
 589        iounmap(base);
 590fail0:
 591        if (pdata && pdata->exit)
 592                pdata->exit(&pdev->dev);
 593        return ret; /* Return error number */
 594}
 595
 596static int __exit i2c_imx_remove(struct platform_device *pdev)
 597{
 598        struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
 599        struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
 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        /* Shut down hardware */
 616        if (pdata && pdata->exit)
 617                pdata->exit(&pdev->dev);
 618
 619        clk_put(i2c_imx->clk);
 620
 621        release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
 622        iounmap(i2c_imx->base);
 623        kfree(i2c_imx);
 624        return 0;
 625}
 626
 627static struct platform_driver i2c_imx_driver = {
 628        .probe          = i2c_imx_probe,
 629        .remove         = __exit_p(i2c_imx_remove),
 630        .driver = {
 631                .name   = DRIVER_NAME,
 632                .owner  = THIS_MODULE,
 633        }
 634};
 635
 636static int __init i2c_adap_imx_init(void)
 637{
 638        return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
 639}
 640subsys_initcall(i2c_adap_imx_init);
 641
 642static void __exit i2c_adap_imx_exit(void)
 643{
 644        platform_driver_unregister(&i2c_imx_driver);
 645}
 646module_exit(i2c_adap_imx_exit);
 647
 648MODULE_LICENSE("GPL");
 649MODULE_AUTHOR("Darius Augulis");
 650MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
 651MODULE_ALIAS("platform:" DRIVER_NAME);
 652