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                         SSYNC();
 200                 } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
 201                                 iface->cur_msg+1 < iface->msg_num) {
 202                         iface->cur_msg++;
 203                         iface->transPtr = iface->pmsg[iface->cur_msg].buf;
 204                         iface->writeNum = iface->readNum =
 205                                 iface->pmsg[iface->cur_msg].len;
 206                         /* Set Transmit device address */
 207                         write_MASTER_ADDR(iface,
 208                                 iface->pmsg[iface->cur_msg].addr);
 209                         if (iface->pmsg[iface->cur_msg].flags & I2C_M_RD)
 210                                 iface->read_write = I2C_SMBUS_READ;
 211                         else {
 212                                 iface->read_write = I2C_SMBUS_WRITE;
 213                                 /* Transmit first data */
 214                                 if (iface->writeNum > 0) {
 215                                         write_XMT_DATA8(iface,
 216                                                 *(iface->transPtr++));
 217                                         iface->writeNum--;
 218                                         SSYNC();
 219                                 }
 220                         }
 221
 222                         if (iface->pmsg[iface->cur_msg].len <= 255)
 223                                         write_MASTER_CTL(iface,
 224                                         (read_MASTER_CTL(iface) &
 225                                         (~(0xff << 6))) |
 226                                 (iface->pmsg[iface->cur_msg].len << 6));
 227                         else {
 228                                 write_MASTER_CTL(iface,
 229                                         (read_MASTER_CTL(iface) |
 230                                         (0xff << 6)));
 231                                 iface->manual_stop = 1;
 232                         }
 233                         /* remove restart bit and enable master receive */
 234                         write_MASTER_CTL(iface,
 235                                 read_MASTER_CTL(iface) & ~RSTART);
 236                         SSYNC();
 237                 } else {
 238                         iface->result = 1;
 239                         write_INT_MASK(iface, 0);
 240                         write_MASTER_CTL(iface, 0);
 241                         SSYNC();
 242                         complete(&iface->complete);
 243                 }
 244         }
 245 }
 246
 247 /* Interrupt handler */
 248 static irqreturn_t bfin_twi_interrupt_entry(int irq, void *dev_id)
 249 {
 250         struct bfin_twi_iface *iface = dev_id;
 251         unsigned long flags;
 252
 253         spin_lock_irqsave(&iface->lock, flags);
 254         del_timer(&iface->timeout_timer);
 255         bfin_twi_handle_interrupt(iface);
 256         spin_unlock_irqrestore(&iface->lock, flags);
 257         return IRQ_HANDLED;
 258 }
 259
 260 static void bfin_twi_timeout(unsigned long data)
 261 {
 262         struct bfin_twi_iface *iface = (struct bfin_twi_iface *)data;
 263         unsigned long flags;
 264
 265         spin_lock_irqsave(&iface->lock, flags);
 266         bfin_twi_handle_interrupt(iface);
 267         if (iface->result == 0) {
 268                 iface->timeout_count--;
 269                 if (iface->timeout_count > 0) {
 270                         iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
 271                         add_timer(&iface->timeout_timer);
 272                 } else {
 273                         iface->result = -1;
 274                         complete(&iface->complete);
 275                 }
 276         }
 277         spin_unlock_irqrestore(&iface->lock, flags);
 278 }
 279
 280 /*
 281  * Generic i2c master transfer entrypoint
 282  */
 283 static int bfin_twi_master_xfer(struct i2c_adapter *adap,
 284                                 struct i2c_msg *msgs, int num)
 285 {
 286         struct bfin_twi_iface *iface = adap->algo_data;
 287         struct i2c_msg *pmsg;
 288         int rc = 0;
 289
 290         if (!(read_CONTROL(iface) & TWI_ENA))
 291                 return -ENXIO;
 292
 293         while (read_MASTER_STAT(iface) & BUSBUSY)
 294                 yield();
 295
 296         iface->pmsg = msgs;
 297         iface->msg_num = num;
 298         iface->cur_msg = 0;
 299
 300         pmsg = &msgs[0];
 301         if (pmsg->flags & I2C_M_TEN) {
 302                 dev_err(&adap->dev, "10 bits addr not supported!\n");
 303                 return -EINVAL;
 304         }
 305
 306         iface->cur_mode = TWI_I2C_MODE_REPEAT;
 307         iface->manual_stop = 0;
 308         iface->transPtr = pmsg->buf;
 309         iface->writeNum = iface->readNum = pmsg->len;
 310         iface->result = 0;
 311         iface->timeout_count = 10;
 312         init_completion(&(iface->complete));
 313         /* Set Transmit device address */
 314         write_MASTER_ADDR(iface, pmsg->addr);
 315
 316         /* FIFO Initiation. Data in FIFO should be
 317          *  discarded before start a new operation.
 318          */
 319         write_FIFO_CTL(iface, 0x3);
 320         SSYNC();
 321         write_FIFO_CTL(iface, 0);
 322         SSYNC();
 323
 324         if (pmsg->flags & I2C_M_RD)
 325                 iface->read_write = I2C_SMBUS_READ;
 326         else {
 327                 iface->read_write = I2C_SMBUS_WRITE;
 328                 /* Transmit first data */
 329                 if (iface->writeNum > 0) {
 330                         write_XMT_DATA8(iface, *(iface->transPtr++));
 331                         iface->writeNum--;
 332                         SSYNC();
 333                 }
 334         }
 335
 336         /* clear int stat */
 337         write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
 338
 339         /* Interrupt mask . Enable XMT, RCV interrupt */
 340         write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
 341         SSYNC();
 342
 343         if (pmsg->len <= 255)
 344                 write_MASTER_CTL(iface, pmsg->len << 6);
 345         else {
 346                 write_MASTER_CTL(iface, 0xff << 6);
 347                 iface->manual_stop = 1;
 348         }
 349
 350         iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
 351         add_timer(&iface->timeout_timer);
 352
 353         /* Master enable */
 354         write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 355                 ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
 356                 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
 357         SSYNC();
 358
 359         wait_for_completion(&iface->complete);
 360
 361         rc = iface->result;
 362
 363         if (rc == 1)
 364                 return num;
 365         else
 366                 return rc;
 367 }
 368
 369 /*
 370  * SMBus type transfer entrypoint
 371  */
 372
 373 int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
 374                         unsigned short flags, char read_write,
 375                         u8 command, int size, union i2c_smbus_data *data)
 376 {
 377         struct bfin_twi_iface *iface = adap->algo_data;
 378         int rc = 0;
 379
 380         if (!(read_CONTROL(iface) & TWI_ENA))
 381                 return -ENXIO;
 382
 383         while (read_MASTER_STAT(iface) & BUSBUSY)
 384                 yield();
 385
 386         iface->writeNum = 0;
 387         iface->readNum = 0;
 388
 389         /* Prepare datas & select mode */
 390         switch (size) {
 391         case I2C_SMBUS_QUICK:
 392                 iface->transPtr = NULL;
 393                 iface->cur_mode = TWI_I2C_MODE_STANDARD;
 394                 break;
 395         case I2C_SMBUS_BYTE:
 396                 if (data == NULL)
 397                         iface->transPtr = NULL;
 398                 else {
 399                         if (read_write == I2C_SMBUS_READ)
 400                                 iface->readNum = 1;
 401                         else
 402                                 iface->writeNum = 1;
 403                         iface->transPtr = &data->byte;
 404                 }
 405                 iface->cur_mode = TWI_I2C_MODE_STANDARD;
 406                 break;
 407         case I2C_SMBUS_BYTE_DATA:
 408                 if (read_write == I2C_SMBUS_READ) {
 409                         iface->readNum = 1;
 410                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 411                 } else {
 412                         iface->writeNum = 1;
 413                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 414                 }
 415                 iface->transPtr = &data->byte;
 416                 break;
 417         case I2C_SMBUS_WORD_DATA:
 418                 if (read_write == I2C_SMBUS_READ) {
 419                         iface->readNum = 2;
 420                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 421                 } else {
 422                         iface->writeNum = 2;
 423                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 424                 }
 425                 iface->transPtr = (u8 *)&data->word;
 426                 break;
 427         case I2C_SMBUS_PROC_CALL:
 428                 iface->writeNum = 2;
 429                 iface->readNum = 2;
 430                 iface->cur_mode = TWI_I2C_MODE_COMBINED;
 431                 iface->transPtr = (u8 *)&data->word;
 432                 break;
 433         case I2C_SMBUS_BLOCK_DATA:
 434                 if (read_write == I2C_SMBUS_READ) {
 435                         iface->readNum = 0;
 436                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 437                 } else {
 438                         iface->writeNum = data->block[0] + 1;
 439                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 440                 }
 441                 iface->transPtr = data->block;
 442                 break;
 443         default:
 444                 return -1;
 445         }
 446
 447         iface->result = 0;
 448         iface->manual_stop = 0;
 449         iface->read_write = read_write;
 450         iface->command = command;
 451         iface->timeout_count = 10;
 452         init_completion(&(iface->complete));
 453
 454         /* FIFO Initiation. Data in FIFO should be discarded before
 455          * start a new operation.
 456          */
 457         write_FIFO_CTL(iface, 0x3);
 458         SSYNC();
 459         write_FIFO_CTL(iface, 0);
 460
 461         /* clear int stat */
 462         write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
 463
 464         /* Set Transmit device address */
 465         write_MASTER_ADDR(iface, addr);
 466         SSYNC();
 467
 468         iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
 469         add_timer(&iface->timeout_timer);
 470
 471         switch (iface->cur_mode) {
 472         case TWI_I2C_MODE_STANDARDSUB:
 473                 write_XMT_DATA8(iface, iface->command);
 474                 write_INT_MASK(iface, MCOMP | MERR |
 475                         ((iface->read_write == I2C_SMBUS_READ) ?
 476                         RCVSERV : XMTSERV));
 477                 SSYNC();
 478
 479                 if (iface->writeNum + 1 <= 255)
 480                         write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
 481                 else {
 482                         write_MASTER_CTL(iface, 0xff << 6);
 483                         iface->manual_stop = 1;
 484                 }
 485                 /* Master enable */
 486                 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 487                         ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
 488                 break;
 489         case TWI_I2C_MODE_COMBINED:
 490                 write_XMT_DATA8(iface, iface->command);
 491                 write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
 492                 SSYNC();
 493
 494                 if (iface->writeNum > 0)
 495                         write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
 496                 else
 497                         write_MASTER_CTL(iface, 0x1 << 6);
 498                 /* Master enable */
 499                 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 500                         ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
 501                 break;
 502         default:
 503                 write_MASTER_CTL(iface, 0);
 504                 if (size != I2C_SMBUS_QUICK) {
 505                         /* Don't access xmit data register when this is a
 506                          * read operation.
 507                          */
 508                         if (iface->read_write != I2C_SMBUS_READ) {
 509                                 if (iface->writeNum > 0) {
 510                                         write_XMT_DATA8(iface,
 511                                                 *(iface->transPtr++));
 512                                         if (iface->writeNum <= 255)
 513                                                 write_MASTER_CTL(iface,
 514                                                         iface->writeNum << 6);
 515                                         else {
 516                                                 write_MASTER_CTL(iface,
 517                                                         0xff << 6);
 518                                                 iface->manual_stop = 1;
 519                                         }
 520                                         iface->writeNum--;
 521                                 } else {
 522                                         write_XMT_DATA8(iface, iface->command);
 523                                         write_MASTER_CTL(iface, 1 << 6);
 524                                 }
 525                         } else {
 526                                 if (iface->readNum > 0 && iface->readNum <= 255)
 527                                         write_MASTER_CTL(iface,
 528                                                 iface->readNum << 6);
 529                                 else if (iface->readNum > 255) {
 530                                         write_MASTER_CTL(iface, 0xff << 6);
 531                                         iface->manual_stop = 1;
 532                                 } else {
 533                                         del_timer(&iface->timeout_timer);
 534                                         break;
 535                                 }
 536                         }
 537                 }
 538                 write_INT_MASK(iface, MCOMP | MERR |
 539                         ((iface->read_write == I2C_SMBUS_READ) ?
 540                         RCVSERV : XMTSERV));
 541                 SSYNC();
 542
 543                 /* Master enable */
 544                 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 545                         ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
 546                         ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
 547                 break;
 548         }
 549         SSYNC();
 550
 551         wait_for_completion(&iface->complete);
 552
 553         rc = (iface->result >= 0) ? 0 : -1;
 554
 555         return rc;
 556 }
 557
 558 /*
 559  * Return what the adapter supports
 560  */
 561 static u32 bfin_twi_functionality(struct i2c_adapter *adap)
 562 {
 563         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 564                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 565                I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
 566                I2C_FUNC_I2C;
 567 }
 568
 569 static struct i2c_algorithm bfin_twi_algorithm = {
 570         .master_xfer   = bfin_twi_master_xfer,
 571         .smbus_xfer    = bfin_twi_smbus_xfer,
 572         .functionality = bfin_twi_functionality,
 573 };
 574
 575 static int i2c_bfin_twi_suspend(struct platform_device *pdev, pm_message_t state)
 576 {
 577         struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
 578
 579         iface->saved_clkdiv = read_CLKDIV(iface);
 580         iface->saved_control = read_CONTROL(iface);
 581
 582         free_irq(iface->irq, iface);
 583
 584         /* Disable TWI */
 585         write_CONTROL(iface, iface->saved_control & ~TWI_ENA);
 586
 587         return 0;
 588 }
 589
 590 static int i2c_bfin_twi_resume(struct platform_device *pdev)
 591 {
 592         struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
 593
 594         int rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
 595                 IRQF_DISABLED, pdev->name, iface);
 596         if (rc) {
 597                 dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
 598                 return -ENODEV;
 599         }
 600
 601         /* Resume TWI interface clock as specified */
 602         write_CLKDIV(iface, iface->saved_clkdiv);
 603
 604         /* Resume TWI */
 605         write_CONTROL(iface, iface->saved_control);
 606
 607         return 0;
 608 }
 609
 610 static int i2c_bfin_twi_probe(struct platform_device *pdev)
 611 {
 612         struct bfin_twi_iface *iface;
 613         struct i2c_adapter *p_adap;
 614         struct resource *res;
 615         int rc;
 616         unsigned int clkhilow;
 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->nr = pdev->id;
 655         strlcpy(p_adap->name, pdev->name, sizeof(p_adap->name));
 656         p_adap->algo = &bfin_twi_algorithm;
 657         p_adap->algo_data = iface;
 658         p_adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 659         p_adap->dev.parent = &pdev->dev;
 660
 661         rc = peripheral_request_list(pin_req[pdev->id], "i2c-bfin-twi");
 662         if (rc) {
 663                 dev_err(&pdev->dev, "Can't setup pin mux!\n");
 664                 goto out_error_pin_mux;
 665         }
 666
 667         rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
 668                 IRQF_DISABLED, pdev->name, iface);
 669         if (rc) {
 670                 dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
 671                 rc = -ENODEV;
 672                 goto out_error_req_irq;
 673         }
 674
 675         /* Set TWI internal clock as 10MHz */
 676         write_CONTROL(iface, ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
 677
 678         /*
 679          * We will not end up with a CLKDIV=0 because no one will specify
 680          * 20kHz SCL or less in Kconfig now. (5 * 1024 / 20 = 0x100)
 681          */
 682         clkhilow = 5 * 1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ;
 683
 684         /* Set Twi interface clock as specified */
 685         write_CLKDIV(iface, (clkhilow << 8) | clkhilow);
 686
 687         /* Enable TWI */
 688         write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
 689         SSYNC();
 690
 691         rc = i2c_add_numbered_adapter(p_adap);
 692         if (rc < 0) {
 693                 dev_err(&pdev->dev, "Can't add i2c adapter!\n");
 694                 goto out_error_add_adapter;
 695         }
 696
 697         platform_set_drvdata(pdev, iface);
 698
 699         dev_info(&pdev->dev, "Blackfin BF5xx on-chip I2C TWI Contoller, "
 700                 "regs_base@%p\n", iface->regs_base);
 701
 702         return 0;
 703
 704 out_error_add_adapter:
 705         free_irq(iface->irq, iface);
 706 out_error_req_irq:
 707 out_error_no_irq:
 708         peripheral_free_list(pin_req[pdev->id]);
 709 out_error_pin_mux:
 710         iounmap(iface->regs_base);
 711 out_error_ioremap:
 712 out_error_get_res:
 713         kfree(iface);
 714 out_error_nomem:
 715         return rc;
 716 }
 717
 718 static int i2c_bfin_twi_remove(struct platform_device *pdev)
 719 {
 720         struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
 721
 722         platform_set_drvdata(pdev, NULL);
 723
 724         i2c_del_adapter(&(iface->adap));
 725         free_irq(iface->irq, iface);
 726         peripheral_free_list(pin_req[pdev->id]);
 727         iounmap(iface->regs_base);
 728         kfree(iface);
 729
 730         return 0;
 731 }
 732
 733 static struct platform_driver i2c_bfin_twi_driver = {
 734         .probe          = i2c_bfin_twi_probe,
 735         .remove         = i2c_bfin_twi_remove,
 736         .suspend        = i2c_bfin_twi_suspend,
 737         .resume         = i2c_bfin_twi_resume,
 738         .driver         = {
 739                 .name   = "i2c-bfin-twi",
 740                 .owner  = THIS_MODULE,
 741         },
 742 };
 743
 744 static int __init i2c_bfin_twi_init(void)
 745 {
 746         return platform_driver_register(&i2c_bfin_twi_driver);
 747 }
 748
 749 static void __exit i2c_bfin_twi_exit(void)
 750 {
 751         platform_driver_unregister(&i2c_bfin_twi_driver);
 752 }
 753
 754 module_init(i2c_bfin_twi_init);
 755 module_exit(i2c_bfin_twi_exit);
 756
 757 MODULE_AUTHOR("Bryan Wu, Sonic Zhang");
 758 MODULE_DESCRIPTION("Blackfin BF5xx on-chip I2C TWI Contoller Driver");
 759 MODULE_LICENSE("GPL");
 760 MODULE_ALIAS("platform:i2c-bfin-twi");