git.oblomov.eu Git - linux-2.6/blob - drivers/i2c/busses/i2c-bfin-twi.c

   1 /*
   2  * Blackfin On-Chip Two Wire Interface Driver
   3  *
   4  * Copyright 2005-2007 Analog Devices Inc.
   5  *
   6  * Enter bugs at http://blackfin.uclinux.org/
   7  *
   8  * Licensed under the GPL-2 or later.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/i2c.h>
  15 #include <linux/mm.h>
  16 #include <linux/timer.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/completion.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/platform_device.h>
  21
  22 #include <asm/blackfin.h>
  23 #include <asm/portmux.h>
  24 #include <asm/irq.h>
  25
  26 #define POLL_TIMEOUT       (2 * HZ)
  27
  28 /* SMBus mode*/
  29 #define TWI_I2C_MODE_STANDARD           1
  30 #define TWI_I2C_MODE_STANDARDSUB        2
  31 #define TWI_I2C_MODE_COMBINED           3
  32 #define TWI_I2C_MODE_REPEAT             4
  33
  34 struct bfin_twi_iface {
  35         int                     irq;
  36         spinlock_t              lock;
  37         char                    read_write;
  38         u8                      command;
  39         u8                      *transPtr;
  40         int                     readNum;
  41         int                     writeNum;
  42         int                     cur_mode;
  43         int                     manual_stop;
  44         int                     result;
  45         int                     timeout_count;
  46         struct timer_list       timeout_timer;
  47         struct i2c_adapter      adap;
  48         struct completion       complete;
  49         struct i2c_msg          *pmsg;
  50         int                     msg_num;
  51         int                     cur_msg;
  52         u16                     saved_clkdiv;
  53         u16                     saved_control;
  54         void __iomem            *regs_base;
  55 };
  56
  57
  58 #define DEFINE_TWI_REG(reg, off) \
  59 static inline u16 read_##reg(struct bfin_twi_iface *iface) \
  60         { return bfin_read16(iface->regs_base + (off)); } \
  61 static inline void write_##reg(struct bfin_twi_iface *iface, u16 v) \
  62         { bfin_write16(iface->regs_base + (off), v); }
  63
  64 DEFINE_TWI_REG(CLKDIV, 0x00)
  65 DEFINE_TWI_REG(CONTROL, 0x04)
  66 DEFINE_TWI_REG(SLAVE_CTL, 0x08)
  67 DEFINE_TWI_REG(SLAVE_STAT, 0x0C)
  68 DEFINE_TWI_REG(SLAVE_ADDR, 0x10)
  69 DEFINE_TWI_REG(MASTER_CTL, 0x14)
  70 DEFINE_TWI_REG(MASTER_STAT, 0x18)
  71 DEFINE_TWI_REG(MASTER_ADDR, 0x1C)
  72 DEFINE_TWI_REG(INT_STAT, 0x20)
  73 DEFINE_TWI_REG(INT_MASK, 0x24)
  74 DEFINE_TWI_REG(FIFO_CTL, 0x28)
  75 DEFINE_TWI_REG(FIFO_STAT, 0x2C)
  76 DEFINE_TWI_REG(XMT_DATA8, 0x80)
  77 DEFINE_TWI_REG(XMT_DATA16, 0x84)
  78 DEFINE_TWI_REG(RCV_DATA8, 0x88)
  79 DEFINE_TWI_REG(RCV_DATA16, 0x8C)
  80
  81 static const u16 pin_req[2][3] = {
  82         {P_TWI0_SCL, P_TWI0_SDA, 0},
  83         {P_TWI1_SCL, P_TWI1_SDA, 0},
  84 };
  85
  86 static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
  87 {
  88         unsigned short twi_int_status = read_INT_STAT(iface);
  89         unsigned short mast_stat = read_MASTER_STAT(iface);
  90
  91         if (twi_int_status & XMTSERV) {
  92                 /* Transmit next data */
  93                 if (iface->writeNum > 0) {
  94                         write_XMT_DATA8(iface, *(iface->transPtr++));
  95                         iface->writeNum--;
  96                 }
  97                 /* start receive immediately after complete sending in
  98                  * combine mode.
  99                  */
 100                 else if (iface->cur_mode == TWI_I2C_MODE_COMBINED)
 101                         write_MASTER_CTL(iface,
 102                                 read_MASTER_CTL(iface) | MDIR | RSTART);
 103                 else if (iface->manual_stop)
 104                         write_MASTER_CTL(iface,
 105                                 read_MASTER_CTL(iface) | STOP);
 106                 else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
 107                                 iface->cur_msg+1 < iface->msg_num)
 108                         write_MASTER_CTL(iface,
 109                                 read_MASTER_CTL(iface) | RSTART);
 110                 SSYNC();
 111                 /* Clear status */
 112                 write_INT_STAT(iface, XMTSERV);
 113                 SSYNC();
 114         }
 115         if (twi_int_status & RCVSERV) {
 116                 if (iface->readNum > 0) {
 117                         /* Receive next data */
 118                         *(iface->transPtr) = read_RCV_DATA8(iface);
 119                         if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
 120                                 /* Change combine mode into sub mode after
 121                                  * read first data.
 122                                  */
 123                                 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 124                                 /* Get read number from first byte in block
 125                                  * combine mode.
 126                                  */
 127                                 if (iface->readNum == 1 && iface->manual_stop)
 128                                         iface->readNum = *iface->transPtr + 1;
 129                         }
 130                         iface->transPtr++;
 131                         iface->readNum--;
 132                 } else if (iface->manual_stop) {
 133                         write_MASTER_CTL(iface,
 134                                 read_MASTER_CTL(iface) | STOP);
 135                         SSYNC();
 136                 } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
 137                                 iface->cur_msg+1 < iface->msg_num) {
 138                         write_MASTER_CTL(iface,
 139                                 read_MASTER_CTL(iface) | RSTART);
 140                         SSYNC();
 141                 }
 142                 /* Clear interrupt source */
 143                 write_INT_STAT(iface, RCVSERV);
 144                 SSYNC();
 145         }
 146         if (twi_int_status & MERR) {
 147                 write_INT_STAT(iface, MERR);
 148                 write_INT_MASK(iface, 0);
 149                 write_MASTER_STAT(iface, 0x3e);
 150                 write_MASTER_CTL(iface, 0);
 151                 SSYNC();
 152                 iface->result = -EIO;
 153                 /* if both err and complete int stats are set, return proper
 154                  * results.
 155                  */
 156                 if (twi_int_status & MCOMP) {
 157                         write_INT_STAT(iface, MCOMP);
 158                         write_INT_MASK(iface, 0);
 159                         write_MASTER_CTL(iface, 0);
 160                         SSYNC();
 161                         /* If it is a quick transfer, only address bug no data,
 162                          * not an err, return 1.
 163                          */
 164                         if (iface->writeNum == 0 && (mast_stat & BUFRDERR))
 165                                 iface->result = 1;
 166                         /* If address not acknowledged return -1,
 167                          * else return 0.
 168                          */
 169                         else if (!(mast_stat & ANAK))
 170                                 iface->result = 0;
 171                 }
 172                 complete(&iface->complete);
 173                 return;
 174         }
 175         if (twi_int_status & MCOMP) {
 176                 write_INT_STAT(iface, MCOMP);
 177                 SSYNC();
 178                 if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
 179                         if (iface->readNum == 0) {
 180                                 /* set the read number to 1 and ask for manual
 181                                  * stop in block combine mode
 182                                  */
 183                                 iface->readNum = 1;
 184                                 iface->manual_stop = 1;
 185                                 write_MASTER_CTL(iface,
 186                                         read_MASTER_CTL(iface) | (0xff << 6));
 187                         } else {
 188                                 /* set the readd number in other
 189                                  * combine mode.
 190                                  */
 191                                 write_MASTER_CTL(iface,
 192                                         (read_MASTER_CTL(iface) &
 193                                         (~(0xff << 6))) |
 194                                         (iface->readNum << 6));
 195                         }
 196                         /* remove restart bit and enable master receive */
 197                         write_MASTER_CTL(iface,
 198                                 read_MASTER_CTL(iface) & ~RSTART);
 199                         write_MASTER_CTL(iface,
 200                                 read_MASTER_CTL(iface) | MEN | MDIR);
 201                         SSYNC();
 202                 } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
 203                                 iface->cur_msg+1 < iface->msg_num) {
 204                         iface->cur_msg++;
 205                         iface->transPtr = iface->pmsg[iface->cur_msg].buf;
 206                         iface->writeNum = iface->readNum =
 207                                 iface->pmsg[iface->cur_msg].len;
 208                         /* Set Transmit device address */
 209                         write_MASTER_ADDR(iface,
 210                                 iface->pmsg[iface->cur_msg].addr);
 211                         if (iface->pmsg[iface->cur_msg].flags & I2C_M_RD)
 212                                 iface->read_write = I2C_SMBUS_READ;
 213                         else {
 214                                 iface->read_write = I2C_SMBUS_WRITE;
 215                                 /* Transmit first data */
 216                                 if (iface->writeNum > 0) {
 217                                         write_XMT_DATA8(iface,
 218                                                 *(iface->transPtr++));
 219                                         iface->writeNum--;
 220                                         SSYNC();
 221                                 }
 222                         }
 223
 224                         if (iface->pmsg[iface->cur_msg].len <= 255)
 225                                 write_MASTER_CTL(iface,
 226                                 iface->pmsg[iface->cur_msg].len << 6);
 227                         else {
 228                                 write_MASTER_CTL(iface, 0xff << 6);
 229                                 iface->manual_stop = 1;
 230                         }
 231                         /* remove restart bit and enable master receive */
 232                         write_MASTER_CTL(iface,
 233                                 read_MASTER_CTL(iface) & ~RSTART);
 234                         write_MASTER_CTL(iface, read_MASTER_CTL(iface) |
 235                                 MEN | ((iface->read_write == I2C_SMBUS_READ) ?
 236                                 MDIR : 0));
 237                         SSYNC();
 238                 } else {
 239                         iface->result = 1;
 240                         write_INT_MASK(iface, 0);
 241                         write_MASTER_CTL(iface, 0);
 242                         SSYNC();
 243                         complete(&iface->complete);
 244                 }
 245         }
 246 }
 247
 248 /* Interrupt handler */
 249 static irqreturn_t bfin_twi_interrupt_entry(int irq, void *dev_id)
 250 {
 251         struct bfin_twi_iface *iface = dev_id;
 252         unsigned long flags;
 253
 254         spin_lock_irqsave(&iface->lock, flags);
 255         del_timer(&iface->timeout_timer);
 256         bfin_twi_handle_interrupt(iface);
 257         spin_unlock_irqrestore(&iface->lock, flags);
 258         return IRQ_HANDLED;
 259 }
 260
 261 static void bfin_twi_timeout(unsigned long data)
 262 {
 263         struct bfin_twi_iface *iface = (struct bfin_twi_iface *)data;
 264         unsigned long flags;
 265
 266         spin_lock_irqsave(&iface->lock, flags);
 267         bfin_twi_handle_interrupt(iface);
 268         if (iface->result == 0) {
 269                 iface->timeout_count--;
 270                 if (iface->timeout_count > 0) {
 271                         iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
 272                         add_timer(&iface->timeout_timer);
 273                 } else {
 274                         iface->result = -1;
 275                         complete(&iface->complete);
 276                 }
 277         }
 278         spin_unlock_irqrestore(&iface->lock, flags);
 279 }
 280
 281 /*
 282  * Generic i2c master transfer entrypoint
 283  */
 284 static int bfin_twi_master_xfer(struct i2c_adapter *adap,
 285                                 struct i2c_msg *msgs, int num)
 286 {
 287         struct bfin_twi_iface *iface = adap->algo_data;
 288         struct i2c_msg *pmsg;
 289         int rc = 0;
 290
 291         if (!(read_CONTROL(iface) & TWI_ENA))
 292                 return -ENXIO;
 293
 294         while (read_MASTER_STAT(iface) & BUSBUSY)
 295                 yield();
 296
 297         iface->pmsg = msgs;
 298         iface->msg_num = num;
 299         iface->cur_msg = 0;
 300
 301         pmsg = &msgs[0];
 302         if (pmsg->flags & I2C_M_TEN) {
 303                 dev_err(&adap->dev, "10 bits addr not supported!\n");
 304                 return -EINVAL;
 305         }
 306
 307         iface->cur_mode = TWI_I2C_MODE_REPEAT;
 308         iface->manual_stop = 0;
 309         iface->transPtr = pmsg->buf;
 310         iface->writeNum = iface->readNum = pmsg->len;
 311         iface->result = 0;
 312         iface->timeout_count = 10;
 313         init_completion(&(iface->complete));
 314         /* Set Transmit device address */
 315         write_MASTER_ADDR(iface, pmsg->addr);
 316
 317         /* FIFO Initiation. Data in FIFO should be
 318          *  discarded before start a new operation.
 319          */
 320         write_FIFO_CTL(iface, 0x3);
 321         SSYNC();
 322         write_FIFO_CTL(iface, 0);
 323         SSYNC();
 324
 325         if (pmsg->flags & I2C_M_RD)
 326                 iface->read_write = I2C_SMBUS_READ;
 327         else {
 328                 iface->read_write = I2C_SMBUS_WRITE;
 329                 /* Transmit first data */
 330                 if (iface->writeNum > 0) {
 331                         write_XMT_DATA8(iface, *(iface->transPtr++));
 332                         iface->writeNum--;
 333                         SSYNC();
 334                 }
 335         }
 336
 337         /* clear int stat */
 338         write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
 339
 340         /* Interrupt mask . Enable XMT, RCV interrupt */
 341         write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
 342         SSYNC();
 343
 344         if (pmsg->len <= 255)
 345                 write_MASTER_CTL(iface, pmsg->len << 6);
 346         else {
 347                 write_MASTER_CTL(iface, 0xff << 6);
 348                 iface->manual_stop = 1;
 349         }
 350
 351         iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
 352         add_timer(&iface->timeout_timer);
 353
 354         /* Master enable */
 355         write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 356                 ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
 357                 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
 358         SSYNC();
 359
 360         wait_for_completion(&iface->complete);
 361
 362         rc = iface->result;
 363
 364         if (rc == 1)
 365                 return num;
 366         else
 367                 return rc;
 368 }
 369
 370 /*
 371  * SMBus type transfer entrypoint
 372  */
 373
 374 int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
 375                         unsigned short flags, char read_write,
 376                         u8 command, int size, union i2c_smbus_data *data)
 377 {
 378         struct bfin_twi_iface *iface = adap->algo_data;
 379         int rc = 0;
 380
 381         if (!(read_CONTROL(iface) & TWI_ENA))
 382                 return -ENXIO;
 383
 384         while (read_MASTER_STAT(iface) & BUSBUSY)
 385                 yield();
 386
 387         iface->writeNum = 0;
 388         iface->readNum = 0;
 389
 390         /* Prepare datas & select mode */
 391         switch (size) {
 392         case I2C_SMBUS_QUICK:
 393                 iface->transPtr = NULL;
 394                 iface->cur_mode = TWI_I2C_MODE_STANDARD;
 395                 break;
 396         case I2C_SMBUS_BYTE:
 397                 if (data == NULL)
 398                         iface->transPtr = NULL;
 399                 else {
 400                         if (read_write == I2C_SMBUS_READ)
 401                                 iface->readNum = 1;
 402                         else
 403                                 iface->writeNum = 1;
 404                         iface->transPtr = &data->byte;
 405                 }
 406                 iface->cur_mode = TWI_I2C_MODE_STANDARD;
 407                 break;
 408         case I2C_SMBUS_BYTE_DATA:
 409                 if (read_write == I2C_SMBUS_READ) {
 410                         iface->readNum = 1;
 411                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 412                 } else {
 413                         iface->writeNum = 1;
 414                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 415                 }
 416                 iface->transPtr = &data->byte;
 417                 break;
 418         case I2C_SMBUS_WORD_DATA:
 419                 if (read_write == I2C_SMBUS_READ) {
 420                         iface->readNum = 2;
 421                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 422                 } else {
 423                         iface->writeNum = 2;
 424                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 425                 }
 426                 iface->transPtr = (u8 *)&data->word;
 427                 break;
 428         case I2C_SMBUS_PROC_CALL:
 429                 iface->writeNum = 2;
 430                 iface->readNum = 2;
 431                 iface->cur_mode = TWI_I2C_MODE_COMBINED;
 432                 iface->transPtr = (u8 *)&data->word;
 433                 break;
 434         case I2C_SMBUS_BLOCK_DATA:
 435                 if (read_write == I2C_SMBUS_READ) {
 436                         iface->readNum = 0;
 437                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 438                 } else {
 439                         iface->writeNum = data->block[0] + 1;
 440                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 441                 }
 442                 iface->transPtr = data->block;
 443                 break;
 444         default:
 445                 return -1;
 446         }
 447
 448         iface->result = 0;
 449         iface->manual_stop = 0;
 450         iface->read_write = read_write;
 451         iface->command = command;
 452         iface->timeout_count = 10;
 453         init_completion(&(iface->complete));
 454
 455         /* FIFO Initiation. Data in FIFO should be discarded before
 456          * start a new operation.
 457          */
 458         write_FIFO_CTL(iface, 0x3);
 459         SSYNC();
 460         write_FIFO_CTL(iface, 0);
 461
 462         /* clear int stat */
 463         write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
 464
 465         /* Set Transmit device address */
 466         write_MASTER_ADDR(iface, addr);
 467         SSYNC();
 468
 469         iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
 470         add_timer(&iface->timeout_timer);
 471
 472         switch (iface->cur_mode) {
 473         case TWI_I2C_MODE_STANDARDSUB:
 474                 write_XMT_DATA8(iface, iface->command);
 475                 write_INT_MASK(iface, MCOMP | MERR |
 476                         ((iface->read_write == I2C_SMBUS_READ) ?
 477                         RCVSERV : XMTSERV));
 478                 SSYNC();
 479
 480                 if (iface->writeNum + 1 <= 255)
 481                         write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
 482                 else {
 483                         write_MASTER_CTL(iface, 0xff << 6);
 484                         iface->manual_stop = 1;
 485                 }
 486                 /* Master enable */
 487                 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 488                         ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
 489                 break;
 490         case TWI_I2C_MODE_COMBINED:
 491                 write_XMT_DATA8(iface, iface->command);
 492                 write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
 493                 SSYNC();
 494
 495                 if (iface->writeNum > 0)
 496                         write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
 497                 else
 498                         write_MASTER_CTL(iface, 0x1 << 6);
 499                 /* Master enable */
 500                 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 501                         ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
 502                 break;
 503         default:
 504                 write_MASTER_CTL(iface, 0);
 505                 if (size != I2C_SMBUS_QUICK) {
 506                         /* Don't access xmit data register when this is a
 507                          * read operation.
 508                          */
 509                         if (iface->read_write != I2C_SMBUS_READ) {
 510                                 if (iface->writeNum > 0) {
 511                                         write_XMT_DATA8(iface,
 512                                                 *(iface->transPtr++));
 513                                         if (iface->writeNum <= 255)
 514                                                 write_MASTER_CTL(iface,
 515                                                         iface->writeNum << 6);
 516                                         else {
 517                                                 write_MASTER_CTL(iface,
 518                                                         0xff << 6);
 519                                                 iface->manual_stop = 1;
 520                                         }
 521                                         iface->writeNum--;
 522                                 } else {
 523                                         write_XMT_DATA8(iface, iface->command);
 524                                         write_MASTER_CTL(iface, 1 << 6);
 525                                 }
 526                         } else {
 527                                 if (iface->readNum > 0 && iface->readNum <= 255)
 528                                         write_MASTER_CTL(iface,
 529                                                 iface->readNum << 6);
 530                                 else if (iface->readNum > 255) {
 531                                         write_MASTER_CTL(iface, 0xff << 6);
 532                                         iface->manual_stop = 1;
 533                                 } else {
 534                                         del_timer(&iface->timeout_timer);
 535                                         break;
 536                                 }
 537                         }
 538                 }
 539                 write_INT_MASK(iface, MCOMP | MERR |
 540                         ((iface->read_write == I2C_SMBUS_READ) ?
 541                         RCVSERV : XMTSERV));
 542                 SSYNC();
 543
 544                 /* Master enable */
 545                 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 546                         ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
 547                         ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
 548                 break;
 549         }
 550         SSYNC();
 551
 552         wait_for_completion(&iface->complete);
 553
 554         rc = (iface->result >= 0) ? 0 : -1;
 555
 556         return rc;
 557 }
 558
 559 /*
 560  * Return what the adapter supports
 561  */
 562 static u32 bfin_twi_functionality(struct i2c_adapter *adap)
 563 {
 564         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 565                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 566                I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
 567                I2C_FUNC_I2C;
 568 }
 569
 570 static struct i2c_algorithm bfin_twi_algorithm = {
 571         .master_xfer   = bfin_twi_master_xfer,
 572         .smbus_xfer    = bfin_twi_smbus_xfer,
 573         .functionality = bfin_twi_functionality,
 574 };
 575
 576 static int i2c_bfin_twi_suspend(struct platform_device *pdev, pm_message_t state)
 577 {
 578         struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
 579
 580         iface->saved_clkdiv = read_CLKDIV(iface);
 581         iface->saved_control = read_CONTROL(iface);
 582
 583         free_irq(iface->irq, iface);
 584
 585         /* Disable TWI */
 586         write_CONTROL(iface, iface->saved_control & ~TWI_ENA);
 587
 588         return 0;
 589 }
 590
 591 static int i2c_bfin_twi_resume(struct platform_device *pdev)
 592 {
 593         struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
 594
 595         int rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
 596                 IRQF_DISABLED, pdev->name, iface);
 597         if (rc) {
 598                 dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
 599                 return -ENODEV;
 600         }
 601
 602         /* Resume TWI interface clock as specified */
 603         write_CLKDIV(iface, iface->saved_clkdiv);
 604
 605         /* Resume TWI */
 606         write_CONTROL(iface, iface->saved_control);
 607
 608         return 0;
 609 }
 610
 611 static int i2c_bfin_twi_probe(struct platform_device *pdev)
 612 {
 613         struct bfin_twi_iface *iface;
 614         struct i2c_adapter *p_adap;
 615         struct resource *res;
 616         int rc;
 617
 618         iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL);
 619         if (!iface) {
 620                 dev_err(&pdev->dev, "Cannot allocate memory\n");
 621                 rc = -ENOMEM;
 622                 goto out_error_nomem;
 623         }
 624
 625         spin_lock_init(&(iface->lock));
 626
 627         /* Find and map our resources */
 628         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 629         if (res == NULL) {
 630                 dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
 631                 rc = -ENOENT;
 632                 goto out_error_get_res;
 633         }
 634
 635         iface->regs_base = ioremap(res->start, res->end - res->start + 1);
 636         if (iface->regs_base == NULL) {
 637                 dev_err(&pdev->dev, "Cannot map IO\n");
 638                 rc = -ENXIO;
 639                 goto out_error_ioremap;
 640         }
 641
 642         iface->irq = platform_get_irq(pdev, 0);
 643         if (iface->irq < 0) {
 644                 dev_err(&pdev->dev, "No IRQ specified\n");
 645                 rc = -ENOENT;
 646                 goto out_error_no_irq;
 647         }
 648
 649         init_timer(&(iface->timeout_timer));
 650         iface->timeout_timer.function = bfin_twi_timeout;
 651         iface->timeout_timer.data = (unsigned long)iface;
 652
 653         p_adap = &iface->adap;
 654         p_adap->id = I2C_HW_BLACKFIN;
 655         p_adap->nr = pdev->id;
 656         strlcpy(p_adap->name, pdev->name, sizeof(p_adap->name));
 657         p_adap->algo = &bfin_twi_algorithm;
 658         p_adap->algo_data = iface;
 659         p_adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 660         p_adap->dev.parent = &pdev->dev;
 661
 662         rc = peripheral_request_list(pin_req[pdev->id], "i2c-bfin-twi");
 663         if (rc) {
 664                 dev_err(&pdev->dev, "Can't setup pin mux!\n");
 665                 goto out_error_pin_mux;
 666         }
 667
 668         rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
 669                 IRQF_DISABLED, pdev->name, iface);
 670         if (rc) {
 671                 dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
 672                 rc = -ENODEV;
 673                 goto out_error_req_irq;
 674         }
 675
 676         /* Set TWI internal clock as 10MHz */
 677         write_CONTROL(iface, ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
 678
 679         /* Set Twi interface clock as specified */
 680         write_CLKDIV(iface, ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
 681                         << 8) | ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
 682                         & 0xFF));
 683
 684         /* Enable TWI */
 685         write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
 686         SSYNC();
 687
 688         rc = i2c_add_numbered_adapter(p_adap);
 689         if (rc < 0) {
 690                 dev_err(&pdev->dev, "Can't add i2c adapter!\n");
 691                 goto out_error_add_adapter;
 692         }
 693
 694         platform_set_drvdata(pdev, iface);
 695
 696         dev_info(&pdev->dev, "Blackfin BF5xx on-chip I2C TWI Contoller, "
 697                 "regs_base@%p\n", iface->regs_base);
 698
 699         return 0;
 700
 701 out_error_add_adapter:
 702         free_irq(iface->irq, iface);
 703 out_error_req_irq:
 704 out_error_no_irq:
 705         peripheral_free_list(pin_req[pdev->id]);
 706 out_error_pin_mux:
 707         iounmap(iface->regs_base);
 708 out_error_ioremap:
 709 out_error_get_res:
 710         kfree(iface);
 711 out_error_nomem:
 712         return rc;
 713 }
 714
 715 static int i2c_bfin_twi_remove(struct platform_device *pdev)
 716 {
 717         struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
 718
 719         platform_set_drvdata(pdev, NULL);
 720
 721         i2c_del_adapter(&(iface->adap));
 722         free_irq(iface->irq, iface);
 723         peripheral_free_list(pin_req[pdev->id]);
 724         iounmap(iface->regs_base);
 725         kfree(iface);
 726
 727         return 0;
 728 }
 729
 730 static struct platform_driver i2c_bfin_twi_driver = {
 731         .probe          = i2c_bfin_twi_probe,
 732         .remove         = i2c_bfin_twi_remove,
 733         .suspend        = i2c_bfin_twi_suspend,
 734         .resume         = i2c_bfin_twi_resume,
 735         .driver         = {
 736                 .name   = "i2c-bfin-twi",
 737                 .owner  = THIS_MODULE,
 738         },
 739 };
 740
 741 static int __init i2c_bfin_twi_init(void)
 742 {
 743         return platform_driver_register(&i2c_bfin_twi_driver);
 744 }
 745
 746 static void __exit i2c_bfin_twi_exit(void)
 747 {
 748         platform_driver_unregister(&i2c_bfin_twi_driver);
 749 }
 750
 751 module_init(i2c_bfin_twi_init);
 752 module_exit(i2c_bfin_twi_exit);
 753
 754 MODULE_AUTHOR("Bryan Wu, Sonic Zhang");
 755 MODULE_DESCRIPTION("Blackfin BF5xx on-chip I2C TWI Contoller Driver");
 756 MODULE_LICENSE("GPL");
 757 MODULE_ALIAS("platform:i2c-bfin-twi");