drivers/i2c/busses/i2c-omap.c

   1 /*
   2  * TI OMAP I2C master mode driver
   3  *
   4  * Copyright (C) 2003 MontaVista Software, Inc.
   5  * Copyright (C) 2004 Texas Instruments.
   6  *
   7  * Updated to work with multiple I2C interfaces on 24xx by
   8  * Tony Lindgren <tony@atomide.com> and Imre Deak <imre.deak@nokia.com>
   9  * Copyright (C) 2005 Nokia Corporation
  10  *
  11  * Cleaned up by Juha Yrjölä <juha.yrjola@nokia.com>
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/delay.h>
  30 #include <linux/i2c.h>
  31 #include <linux/err.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/completion.h>
  34 #include <linux/platform_device.h>
  35 #include <linux/clk.h>
  36
  37 #include <asm/io.h>
  38
  39 /* timeout waiting for the controller to respond */
  40 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
  41
  42 #define OMAP_I2C_REV_REG                0x00
  43 #define OMAP_I2C_IE_REG                 0x04
  44 #define OMAP_I2C_STAT_REG               0x08
  45 #define OMAP_I2C_IV_REG                 0x0c
  46 #define OMAP_I2C_SYSS_REG               0x10
  47 #define OMAP_I2C_BUF_REG                0x14
  48 #define OMAP_I2C_CNT_REG                0x18
  49 #define OMAP_I2C_DATA_REG               0x1c
  50 #define OMAP_I2C_SYSC_REG               0x20
  51 #define OMAP_I2C_CON_REG                0x24
  52 #define OMAP_I2C_OA_REG                 0x28
  53 #define OMAP_I2C_SA_REG                 0x2c
  54 #define OMAP_I2C_PSC_REG                0x30
  55 #define OMAP_I2C_SCLL_REG               0x34
  56 #define OMAP_I2C_SCLH_REG               0x38
  57 #define OMAP_I2C_SYSTEST_REG            0x3c
  58
  59 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
  60 #define OMAP_I2C_IE_XRDY        (1 << 4)        /* TX data ready int enable */
  61 #define OMAP_I2C_IE_RRDY        (1 << 3)        /* RX data ready int enable */
  62 #define OMAP_I2C_IE_ARDY        (1 << 2)        /* Access ready int enable */
  63 #define OMAP_I2C_IE_NACK        (1 << 1)        /* No ack interrupt enable */
  64 #define OMAP_I2C_IE_AL          (1 << 0)        /* Arbitration lost int ena */
  65
  66 /* I2C Status Register (OMAP_I2C_STAT): */
  67 #define OMAP_I2C_STAT_SBD       (1 << 15)       /* Single byte data */
  68 #define OMAP_I2C_STAT_BB        (1 << 12)       /* Bus busy */
  69 #define OMAP_I2C_STAT_ROVR      (1 << 11)       /* Receive overrun */
  70 #define OMAP_I2C_STAT_XUDF      (1 << 10)       /* Transmit underflow */
  71 #define OMAP_I2C_STAT_AAS       (1 << 9)        /* Address as slave */
  72 #define OMAP_I2C_STAT_AD0       (1 << 8)        /* Address zero */
  73 #define OMAP_I2C_STAT_XRDY      (1 << 4)        /* Transmit data ready */
  74 #define OMAP_I2C_STAT_RRDY      (1 << 3)        /* Receive data ready */
  75 #define OMAP_I2C_STAT_ARDY      (1 << 2)        /* Register access ready */
  76 #define OMAP_I2C_STAT_NACK      (1 << 1)        /* No ack interrupt enable */
  77 #define OMAP_I2C_STAT_AL        (1 << 0)        /* Arbitration lost int ena */
  78
  79 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
  80 #define OMAP_I2C_BUF_RDMA_EN    (1 << 15)       /* RX DMA channel enable */
  81 #define OMAP_I2C_BUF_XDMA_EN    (1 << 7)        /* TX DMA channel enable */
  82
  83 /* I2C Configuration Register (OMAP_I2C_CON): */
  84 #define OMAP_I2C_CON_EN         (1 << 15)       /* I2C module enable */
  85 #define OMAP_I2C_CON_BE         (1 << 14)       /* Big endian mode */
  86 #define OMAP_I2C_CON_STB        (1 << 11)       /* Start byte mode (master) */
  87 #define OMAP_I2C_CON_MST        (1 << 10)       /* Master/slave mode */
  88 #define OMAP_I2C_CON_TRX        (1 << 9)        /* TX/RX mode (master only) */
  89 #define OMAP_I2C_CON_XA         (1 << 8)        /* Expand address */
  90 #define OMAP_I2C_CON_RM         (1 << 2)        /* Repeat mode (master only) */
  91 #define OMAP_I2C_CON_STP        (1 << 1)        /* Stop cond (master only) */
  92 #define OMAP_I2C_CON_STT        (1 << 0)        /* Start condition (master) */
  93
  94 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
  95 #ifdef DEBUG
  96 #define OMAP_I2C_SYSTEST_ST_EN          (1 << 15)       /* System test enable */
  97 #define OMAP_I2C_SYSTEST_FREE           (1 << 14)       /* Free running mode */
  98 #define OMAP_I2C_SYSTEST_TMODE_MASK     (3 << 12)       /* Test mode select */
  99 #define OMAP_I2C_SYSTEST_TMODE_SHIFT    (12)            /* Test mode select */
 100 #define OMAP_I2C_SYSTEST_SCL_I          (1 << 3)        /* SCL line sense in */
 101 #define OMAP_I2C_SYSTEST_SCL_O          (1 << 2)        /* SCL line drive out */
 102 #define OMAP_I2C_SYSTEST_SDA_I          (1 << 1)        /* SDA line sense in */
 103 #define OMAP_I2C_SYSTEST_SDA_O          (1 << 0)        /* SDA line drive out */
 104 #endif
 105
 106 /* I2C System Status register (OMAP_I2C_SYSS): */
 107 #define OMAP_I2C_SYSS_RDONE             (1 << 0)        /* Reset Done */
 108
 109 /* I2C System Configuration Register (OMAP_I2C_SYSC): */
 110 #define OMAP_I2C_SYSC_SRST              (1 << 1)        /* Soft Reset */
 111
 112 /* REVISIT: Use platform_data instead of module parameters */
 113 /* Fast Mode = 400 kHz, Standard = 100 kHz */
 114 static int clock = 100; /* Default: 100 kHz */
 115 module_param(clock, int, 0);
 116 MODULE_PARM_DESC(clock, "Set I2C clock in kHz: 400=fast mode (default == 100)");
 117
 118 struct omap_i2c_dev {
 119         struct device           *dev;
 120         void __iomem            *base;          /* virtual */
 121         int                     irq;
 122         struct clk              *iclk;          /* Interface clock */
 123         struct clk              *fclk;          /* Functional clock */
 124         struct completion       cmd_complete;
 125         struct resource         *ioarea;
 126         u16                     cmd_err;
 127         u8                      *buf;
 128         size_t                  buf_len;
 129         struct i2c_adapter      adapter;
 130         unsigned                rev1:1;
 131 };
 132
 133 static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
 134                                       int reg, u16 val)
 135 {
 136         __raw_writew(val, i2c_dev->base + reg);
 137 }
 138
 139 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
 140 {
 141         return __raw_readw(i2c_dev->base + reg);
 142 }
 143
 144 static int omap_i2c_get_clocks(struct omap_i2c_dev *dev)
 145 {
 146         if (cpu_is_omap16xx() || cpu_is_omap24xx()) {
 147                 dev->iclk = clk_get(dev->dev, "i2c_ick");
 148                 if (IS_ERR(dev->iclk)) {
 149                         dev->iclk = NULL;
 150                         return -ENODEV;
 151                 }
 152         }
 153
 154         dev->fclk = clk_get(dev->dev, "i2c_fck");
 155         if (IS_ERR(dev->fclk)) {
 156                 if (dev->iclk != NULL) {
 157                         clk_put(dev->iclk);
 158                         dev->iclk = NULL;
 159                 }
 160                 dev->fclk = NULL;
 161                 return -ENODEV;
 162         }
 163
 164         return 0;
 165 }
 166
 167 static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
 168 {
 169         clk_put(dev->fclk);
 170         dev->fclk = NULL;
 171         if (dev->iclk != NULL) {
 172                 clk_put(dev->iclk);
 173                 dev->iclk = NULL;
 174         }
 175 }
 176
 177 static void omap_i2c_enable_clocks(struct omap_i2c_dev *dev)
 178 {
 179         if (dev->iclk != NULL)
 180                 clk_enable(dev->iclk);
 181         clk_enable(dev->fclk);
 182 }
 183
 184 static void omap_i2c_disable_clocks(struct omap_i2c_dev *dev)
 185 {
 186         if (dev->iclk != NULL)
 187                 clk_disable(dev->iclk);
 188         clk_disable(dev->fclk);
 189 }
 190
 191 static int omap_i2c_init(struct omap_i2c_dev *dev)
 192 {
 193         u16 psc = 0;
 194         unsigned long fclk_rate = 12000000;
 195         unsigned long timeout;
 196
 197         if (!dev->rev1) {
 198                 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, OMAP_I2C_SYSC_SRST);
 199                 /* For some reason we need to set the EN bit before the
 200                  * reset done bit gets set. */
 201                 timeout = jiffies + OMAP_I2C_TIMEOUT;
 202                 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
 203                 while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
 204                          OMAP_I2C_SYSS_RDONE)) {
 205                         if (time_after(jiffies, timeout)) {
 206                                 dev_warn(dev->dev, "timeout waiting "
 207                                                 "for controller reset\n");
 208                                 return -ETIMEDOUT;
 209                         }
 210                         msleep(1);
 211                 }
 212         }
 213         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
 214
 215         if (cpu_class_is_omap1()) {
 216                 struct clk *armxor_ck;
 217
 218                 armxor_ck = clk_get(NULL, "armxor_ck");
 219                 if (IS_ERR(armxor_ck))
 220                         dev_warn(dev->dev, "Could not get armxor_ck\n");
 221                 else {
 222                         fclk_rate = clk_get_rate(armxor_ck);
 223                         clk_put(armxor_ck);
 224                 }
 225                 /* TRM for 5912 says the I2C clock must be prescaled to be
 226                  * between 7 - 12 MHz. The XOR input clock is typically
 227                  * 12, 13 or 19.2 MHz. So we should have code that produces:
 228                  *
 229                  * XOR MHz      Divider         Prescaler
 230                  * 12           1               0
 231                  * 13           2               1
 232                  * 19.2         2               1
 233                  */
 234                 if (fclk_rate > 12000000)
 235                         psc = fclk_rate / 12000000;
 236         }
 237
 238         /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
 239         omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
 240
 241         /* Program desired operating rate */
 242         fclk_rate /= (psc + 1) * 1000;
 243         if (psc > 2)
 244                 psc = 2;
 245
 246         omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG,
 247                            fclk_rate / (clock * 2) - 7 + psc);
 248         omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG,
 249                            fclk_rate / (clock * 2) - 7 + psc);
 250
 251         /* Take the I2C module out of reset: */
 252         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
 253
 254         /* Enable interrupts */
 255         omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
 256                            (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
 257                             OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
 258                             OMAP_I2C_IE_AL));
 259         return 0;
 260 }
 261
 262 /*
 263  * Waiting on Bus Busy
 264  */
 265 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
 266 {
 267         unsigned long timeout;
 268
 269         timeout = jiffies + OMAP_I2C_TIMEOUT;
 270         while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
 271                 if (time_after(jiffies, timeout)) {
 272                         dev_warn(dev->dev, "timeout waiting for bus ready\n");
 273                         return -ETIMEDOUT;
 274                 }
 275                 msleep(1);
 276         }
 277
 278         return 0;
 279 }
 280
 281 /*
 282  * Low level master read/write transaction.
 283  */
 284 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 285                              struct i2c_msg *msg, int stop)
 286 {
 287         struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
 288         int r;
 289         u16 w;
 290
 291         dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
 292                 msg->addr, msg->len, msg->flags, stop);
 293
 294         if (msg->len == 0)
 295                 return -EINVAL;
 296
 297         omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
 298
 299         /* REVISIT: Could the STB bit of I2C_CON be used with probing? */
 300         dev->buf = msg->buf;
 301         dev->buf_len = msg->len;
 302
 303         omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
 304
 305         init_completion(&dev->cmd_complete);
 306         dev->cmd_err = 0;
 307
 308         w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
 309         if (msg->flags & I2C_M_TEN)
 310                 w |= OMAP_I2C_CON_XA;
 311         if (!(msg->flags & I2C_M_RD))
 312                 w |= OMAP_I2C_CON_TRX;
 313         if (stop)
 314                 w |= OMAP_I2C_CON_STP;
 315         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
 316
 317         r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
 318                                                       OMAP_I2C_TIMEOUT);
 319         dev->buf_len = 0;
 320         if (r < 0)
 321                 return r;
 322         if (r == 0) {
 323                 dev_err(dev->dev, "controller timed out\n");
 324                 omap_i2c_init(dev);
 325                 return -ETIMEDOUT;
 326         }
 327
 328         if (likely(!dev->cmd_err))
 329                 return 0;
 330
 331         /* We have an error */
 332         if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
 333                             OMAP_I2C_STAT_XUDF)) {
 334                 omap_i2c_init(dev);
 335                 return -EIO;
 336         }
 337
 338         if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
 339                 if (msg->flags & I2C_M_IGNORE_NAK)
 340                         return 0;
 341                 if (stop) {
 342                         w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
 343                         w |= OMAP_I2C_CON_STP;
 344                         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
 345                 }
 346                 return -EREMOTEIO;
 347         }
 348         return -EIO;
 349 }
 350
 351
 352 /*
 353  * Prepare controller for a transaction and call omap_i2c_xfer_msg
 354  * to do the work during IRQ processing.
 355  */
 356 static int
 357 omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 358 {
 359         struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
 360         int i;
 361         int r;
 362
 363         omap_i2c_enable_clocks(dev);
 364
 365         /* REVISIT: initialize and use adap->retries. This is an optional
 366          * feature */
 367         if ((r = omap_i2c_wait_for_bb(dev)) < 0)
 368                 goto out;
 369
 370         for (i = 0; i < num; i++) {
 371                 r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
 372                 if (r != 0)
 373                         break;
 374         }
 375
 376         if (r == 0)
 377                 r = num;
 378 out:
 379         omap_i2c_disable_clocks(dev);
 380         return r;
 381 }
 382
 383 static u32
 384 omap_i2c_func(struct i2c_adapter *adap)
 385 {
 386         return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 387 }
 388
 389 static inline void
 390 omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
 391 {
 392         dev->cmd_err |= err;
 393         complete(&dev->cmd_complete);
 394 }
 395
 396 static inline void
 397 omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
 398 {
 399         omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
 400 }
 401
 402 static irqreturn_t
 403 omap_i2c_rev1_isr(int this_irq, void *dev_id)
 404 {
 405         struct omap_i2c_dev *dev = dev_id;
 406         u16 iv, w;
 407
 408         iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
 409         switch (iv) {
 410         case 0x00:      /* None */
 411                 break;
 412         case 0x01:      /* Arbitration lost */
 413                 dev_err(dev->dev, "Arbitration lost\n");
 414                 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
 415                 break;
 416         case 0x02:      /* No acknowledgement */
 417                 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
 418                 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
 419                 break;
 420         case 0x03:      /* Register access ready */
 421                 omap_i2c_complete_cmd(dev, 0);
 422                 break;
 423         case 0x04:      /* Receive data ready */
 424                 if (dev->buf_len) {
 425                         w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
 426                         *dev->buf++ = w;
 427                         dev->buf_len--;
 428                         if (dev->buf_len) {
 429                                 *dev->buf++ = w >> 8;
 430                                 dev->buf_len--;
 431                         }
 432                 } else
 433                         dev_err(dev->dev, "RRDY IRQ while no data requested\n");
 434                 break;
 435         case 0x05:      /* Transmit data ready */
 436                 if (dev->buf_len) {
 437                         w = *dev->buf++;
 438                         dev->buf_len--;
 439                         if (dev->buf_len) {
 440                                 w |= *dev->buf++ << 8;
 441                                 dev->buf_len--;
 442                         }
 443                         omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
 444                 } else
 445                         dev_err(dev->dev, "XRDY IRQ while no data to send\n");
 446                 break;
 447         default:
 448                 return IRQ_NONE;
 449         }
 450
 451         return IRQ_HANDLED;
 452 }
 453
 454 static irqreturn_t
 455 omap_i2c_isr(int this_irq, void *dev_id)
 456 {
 457         struct omap_i2c_dev *dev = dev_id;
 458         u16 bits;
 459         u16 stat, w;
 460         int count = 0;
 461
 462         bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
 463         while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
 464                 dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
 465                 if (count++ == 100) {
 466                         dev_warn(dev->dev, "Too much work in one IRQ\n");
 467                         break;
 468                 }
 469
 470                 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
 471
 472                 if (stat & OMAP_I2C_STAT_ARDY) {
 473                         omap_i2c_complete_cmd(dev, 0);
 474                         continue;
 475                 }
 476                 if (stat & OMAP_I2C_STAT_RRDY) {
 477                         w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
 478                         if (dev->buf_len) {
 479                                 *dev->buf++ = w;
 480                                 dev->buf_len--;
 481                                 if (dev->buf_len) {
 482                                         *dev->buf++ = w >> 8;
 483                                         dev->buf_len--;
 484                                 }
 485                         } else
 486                                 dev_err(dev->dev, "RRDY IRQ while no data "
 487                                                 "requested\n");
 488                         omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
 489                         continue;
 490                 }
 491                 if (stat & OMAP_I2C_STAT_XRDY) {
 492                         w = 0;
 493                         if (dev->buf_len) {
 494                                 w = *dev->buf++;
 495                                 dev->buf_len--;
 496                                 if (dev->buf_len) {
 497                                         w |= *dev->buf++ << 8;
 498                                         dev->buf_len--;
 499                                 }
 500                         } else
 501                                 dev_err(dev->dev, "XRDY IRQ while no "
 502                                         "data to send\n");
 503                         omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
 504                         omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
 505                         continue;
 506                 }
 507                 if (stat & OMAP_I2C_STAT_ROVR) {
 508                         dev_err(dev->dev, "Receive overrun\n");
 509                         dev->cmd_err |= OMAP_I2C_STAT_ROVR;
 510                 }
 511                 if (stat & OMAP_I2C_STAT_XUDF) {
 512                         dev_err(dev->dev, "Transmit overflow\n");
 513                         dev->cmd_err |= OMAP_I2C_STAT_XUDF;
 514                 }
 515                 if (stat & OMAP_I2C_STAT_NACK) {
 516                         omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
 517                         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
 518                                            OMAP_I2C_CON_STP);
 519                 }
 520                 if (stat & OMAP_I2C_STAT_AL) {
 521                         dev_err(dev->dev, "Arbitration lost\n");
 522                         omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
 523                 }
 524         }
 525
 526         return count ? IRQ_HANDLED : IRQ_NONE;
 527 }
 528
 529 static const struct i2c_algorithm omap_i2c_algo = {
 530         .master_xfer    = omap_i2c_xfer,
 531         .functionality  = omap_i2c_func,
 532 };
 533
 534 static int
 535 omap_i2c_probe(struct platform_device *pdev)
 536 {
 537         struct omap_i2c_dev     *dev;
 538         struct i2c_adapter      *adap;
 539         struct resource         *mem, *irq, *ioarea;
 540         int r;
 541
 542         /* NOTE: driver uses the static register mapping */
 543         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 544         if (!mem) {
 545                 dev_err(&pdev->dev, "no mem resource?\n");
 546                 return -ENODEV;
 547         }
 548         irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 549         if (!irq) {
 550                 dev_err(&pdev->dev, "no irq resource?\n");
 551                 return -ENODEV;
 552         }
 553
 554         ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
 555                         pdev->name);
 556         if (!ioarea) {
 557                 dev_err(&pdev->dev, "I2C region already claimed\n");
 558                 return -EBUSY;
 559         }
 560
 561         if (clock > 200)
 562                 clock = 400;    /* Fast mode */
 563         else
 564                 clock = 100;    /* Standard mode */
 565
 566         dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
 567         if (!dev) {
 568                 r = -ENOMEM;
 569                 goto err_release_region;
 570         }
 571
 572         dev->dev = &pdev->dev;
 573         dev->irq = irq->start;
 574         dev->base = (void __iomem *) IO_ADDRESS(mem->start);
 575         platform_set_drvdata(pdev, dev);
 576
 577         if ((r = omap_i2c_get_clocks(dev)) != 0)
 578                 goto err_free_mem;
 579
 580         omap_i2c_enable_clocks(dev);
 581
 582         if (cpu_is_omap15xx())
 583                 dev->rev1 = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) < 0x20;
 584
 585         /* reset ASAP, clearing any IRQs */
 586         omap_i2c_init(dev);
 587
 588         r = request_irq(dev->irq, dev->rev1 ? omap_i2c_rev1_isr : omap_i2c_isr,
 589                         0, pdev->name, dev);
 590
 591         if (r) {
 592                 dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
 593                 goto err_unuse_clocks;
 594         }
 595         r = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
 596         dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
 597                  pdev->id, r >> 4, r & 0xf, clock);
 598
 599         adap = &dev->adapter;
 600         i2c_set_adapdata(adap, dev);
 601         adap->owner = THIS_MODULE;
 602         adap->class = I2C_CLASS_HWMON;
 603         strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
 604         adap->algo = &omap_i2c_algo;
 605         adap->dev.parent = &pdev->dev;
 606
 607         /* i2c device drivers may be active on return from add_adapter() */
 608         adap->nr = pdev->id;
 609         r = i2c_add_numbered_adapter(adap);
 610         if (r) {
 611                 dev_err(dev->dev, "failure adding adapter\n");
 612                 goto err_free_irq;
 613         }
 614
 615         omap_i2c_disable_clocks(dev);
 616
 617         return 0;
 618
 619 err_free_irq:
 620         free_irq(dev->irq, dev);
 621 err_unuse_clocks:
 622         omap_i2c_disable_clocks(dev);
 623         omap_i2c_put_clocks(dev);
 624 err_free_mem:
 625         platform_set_drvdata(pdev, NULL);
 626         kfree(dev);
 627 err_release_region:
 628         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
 629         release_mem_region(mem->start, (mem->end - mem->start) + 1);
 630
 631         return r;
 632 }
 633
 634 static int
 635 omap_i2c_remove(struct platform_device *pdev)
 636 {
 637         struct omap_i2c_dev     *dev = platform_get_drvdata(pdev);
 638         struct resource         *mem;
 639
 640         platform_set_drvdata(pdev, NULL);
 641
 642         free_irq(dev->irq, dev);
 643         i2c_del_adapter(&dev->adapter);
 644         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
 645         omap_i2c_put_clocks(dev);
 646         kfree(dev);
 647         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 648         release_mem_region(mem->start, (mem->end - mem->start) + 1);
 649         return 0;
 650 }
 651
 652 static struct platform_driver omap_i2c_driver = {
 653         .probe          = omap_i2c_probe,
 654         .remove         = omap_i2c_remove,
 655         .driver         = {
 656                 .name   = "i2c_omap",
 657                 .owner  = THIS_MODULE,
 658         },
 659 };
 660
 661 /* I2C may be needed to bring up other drivers */
 662 static int __init
 663 omap_i2c_init_driver(void)
 664 {
 665         return platform_driver_register(&omap_i2c_driver);
 666 }
 667 subsys_initcall(omap_i2c_init_driver);
 668
 669 static void __exit omap_i2c_exit_driver(void)
 670 {
 671         platform_driver_unregister(&omap_i2c_driver);
 672 }
 673 module_exit(omap_i2c_exit_driver);
 674
 675 MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
 676 MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
 677 MODULE_LICENSE("GPL");