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/slab.h>
  16 #include <linux/io.h>
  17 #include <linux/mm.h>
  18 #include <linux/timer.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/completion.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/delay.h>
  24
  25 #include <asm/irq.h>
  26 #include <asm/portmux.h>
  27 #include <asm/bfin_twi.h>
  28
  29 /* SMBus mode*/
  30 #define TWI_I2C_MODE_STANDARD           1
  31 #define TWI_I2C_MODE_STANDARDSUB        2
  32 #define TWI_I2C_MODE_COMBINED           3
  33 #define TWI_I2C_MODE_REPEAT             4
  34
  35 static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface,
  36                                         unsigned short twi_int_status)
  37 {
  38         unsigned short mast_stat = read_MASTER_STAT(iface);
  39
  40         if (twi_int_status & XMTSERV) {
  41                 if (iface->writeNum <= 0) {
  42                         /* start receive immediately after complete sending in
  43                          * combine mode.
  44                          */
  45                         if (iface->cur_mode == TWI_I2C_MODE_COMBINED)
  46                                 write_MASTER_CTL(iface,
  47                                         read_MASTER_CTL(iface) | MDIR);
  48                         else if (iface->manual_stop)
  49                                 write_MASTER_CTL(iface,
  50                                         read_MASTER_CTL(iface) | STOP);
  51                         else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
  52                                 iface->cur_msg + 1 < iface->msg_num) {
  53                                 if (iface->pmsg[iface->cur_msg + 1].flags &
  54                                         I2C_M_RD)
  55                                         write_MASTER_CTL(iface,
  56                                                 read_MASTER_CTL(iface) |
  57                                                 MDIR);
  58                                 else
  59                                         write_MASTER_CTL(iface,
  60                                                 read_MASTER_CTL(iface) &
  61                                                 ~MDIR);
  62                         }
  63                 }
  64                 /* Transmit next data */
  65                 while (iface->writeNum > 0 &&
  66                         (read_FIFO_STAT(iface) & XMTSTAT) != XMT_FULL) {
  67                         write_XMT_DATA8(iface, *(iface->transPtr++));
  68                         iface->writeNum--;
  69                 }
  70         }
  71         if (twi_int_status & RCVSERV) {
  72                 while (iface->readNum > 0 &&
  73                         (read_FIFO_STAT(iface) & RCVSTAT)) {
  74                         /* Receive next data */
  75                         *(iface->transPtr) = read_RCV_DATA8(iface);
  76                         if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
  77                                 /* Change combine mode into sub mode after
  78                                  * read first data.
  79                                  */
  80                                 iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
  81                                 /* Get read number from first byte in block
  82                                  * combine mode.
  83                                  */
  84                                 if (iface->readNum == 1 && iface->manual_stop)
  85                                         iface->readNum = *iface->transPtr + 1;
  86                         }
  87                         iface->transPtr++;
  88                         iface->readNum--;
  89                 }
  90
  91                 if (iface->readNum == 0) {
  92                         if (iface->manual_stop) {
  93                                 /* Temporary workaround to avoid possible bus stall -
  94                                  * Flush FIFO before issuing the STOP condition
  95                                  */
  96                                 read_RCV_DATA16(iface);
  97                                 write_MASTER_CTL(iface,
  98                                         read_MASTER_CTL(iface) | STOP);
  99                         } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
 100                                         iface->cur_msg + 1 < iface->msg_num) {
 101                                 if (iface->pmsg[iface->cur_msg + 1].flags & I2C_M_RD)
 102                                         write_MASTER_CTL(iface,
 103                                                 read_MASTER_CTL(iface) | MDIR);
 104                                 else
 105                                         write_MASTER_CTL(iface,
 106                                                 read_MASTER_CTL(iface) & ~MDIR);
 107                         }
 108                 }
 109         }
 110         if (twi_int_status & MERR) {
 111                 write_INT_MASK(iface, 0);
 112                 write_MASTER_STAT(iface, 0x3e);
 113                 write_MASTER_CTL(iface, 0);
 114                 iface->result = -EIO;
 115
 116                 if (mast_stat & LOSTARB)
 117                         dev_dbg(&iface->adap.dev, "Lost Arbitration\n");
 118                 if (mast_stat & ANAK)
 119                         dev_dbg(&iface->adap.dev, "Address Not Acknowledged\n");
 120                 if (mast_stat & DNAK)
 121                         dev_dbg(&iface->adap.dev, "Data Not Acknowledged\n");
 122                 if (mast_stat & BUFRDERR)
 123                         dev_dbg(&iface->adap.dev, "Buffer Read Error\n");
 124                 if (mast_stat & BUFWRERR)
 125                         dev_dbg(&iface->adap.dev, "Buffer Write Error\n");
 126
 127                 /* Faulty slave devices, may drive SDA low after a transfer
 128                  * finishes. To release the bus this code generates up to 9
 129                  * extra clocks until SDA is released.
 130                  */
 131
 132                 if (read_MASTER_STAT(iface) & SDASEN) {
 133                         int cnt = 9;
 134                         do {
 135                                 write_MASTER_CTL(iface, SCLOVR);
 136                                 udelay(6);
 137                                 write_MASTER_CTL(iface, 0);
 138                                 udelay(6);
 139                         } while ((read_MASTER_STAT(iface) & SDASEN) && cnt--);
 140
 141                         write_MASTER_CTL(iface, SDAOVR | SCLOVR);
 142                         udelay(6);
 143                         write_MASTER_CTL(iface, SDAOVR);
 144                         udelay(6);
 145                         write_MASTER_CTL(iface, 0);
 146                 }
 147
 148                 /* If it is a quick transfer, only address without data,
 149                  * not an err, return 1.
 150                  */
 151                 if (iface->cur_mode == TWI_I2C_MODE_STANDARD &&
 152                         iface->transPtr == NULL &&
 153                         (twi_int_status & MCOMP) && (mast_stat & DNAK))
 154                         iface->result = 1;
 155
 156                 complete(&iface->complete);
 157                 return;
 158         }
 159         if (twi_int_status & MCOMP) {
 160                 if (twi_int_status & (XMTSERV | RCVSERV) &&
 161                         (read_MASTER_CTL(iface) & MEN) == 0 &&
 162                         (iface->cur_mode == TWI_I2C_MODE_REPEAT ||
 163                         iface->cur_mode == TWI_I2C_MODE_COMBINED)) {
 164                         iface->result = -1;
 165                         write_INT_MASK(iface, 0);
 166                         write_MASTER_CTL(iface, 0);
 167                 } else if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
 168                         if (iface->readNum == 0) {
 169                                 /* set the read number to 1 and ask for manual
 170                                  * stop in block combine mode
 171                                  */
 172                                 iface->readNum = 1;
 173                                 iface->manual_stop = 1;
 174                                 write_MASTER_CTL(iface,
 175                                         read_MASTER_CTL(iface) | (0xff << 6));
 176                         } else {
 177                                 /* set the readd number in other
 178                                  * combine mode.
 179                                  */
 180                                 write_MASTER_CTL(iface,
 181                                         (read_MASTER_CTL(iface) &
 182                                         (~(0xff << 6))) |
 183                                         (iface->readNum << 6));
 184                         }
 185                         /* remove restart bit and enable master receive */
 186                         write_MASTER_CTL(iface,
 187                                 read_MASTER_CTL(iface) & ~RSTART);
 188                 } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
 189                                 iface->cur_msg + 1 < iface->msg_num) {
 190                         iface->cur_msg++;
 191                         iface->transPtr = iface->pmsg[iface->cur_msg].buf;
 192                         iface->writeNum = iface->readNum =
 193                                 iface->pmsg[iface->cur_msg].len;
 194                         /* Set Transmit device address */
 195                         write_MASTER_ADDR(iface,
 196                                 iface->pmsg[iface->cur_msg].addr);
 197                         if (iface->pmsg[iface->cur_msg].flags & I2C_M_RD)
 198                                 iface->read_write = I2C_SMBUS_READ;
 199                         else {
 200                                 iface->read_write = I2C_SMBUS_WRITE;
 201                                 /* Transmit first data */
 202                                 if (iface->writeNum > 0) {
 203                                         write_XMT_DATA8(iface,
 204                                                 *(iface->transPtr++));
 205                                         iface->writeNum--;
 206                                 }
 207                         }
 208
 209                         if (iface->pmsg[iface->cur_msg].len <= 255) {
 210                                 write_MASTER_CTL(iface,
 211                                         (read_MASTER_CTL(iface) &
 212                                         (~(0xff << 6))) |
 213                                         (iface->pmsg[iface->cur_msg].len << 6));
 214                                 iface->manual_stop = 0;
 215                         } else {
 216                                 write_MASTER_CTL(iface,
 217                                         (read_MASTER_CTL(iface) |
 218                                         (0xff << 6)));
 219                                 iface->manual_stop = 1;
 220                         }
 221                         /* remove restart bit before last message */
 222                         if (iface->cur_msg + 1 == iface->msg_num)
 223                                 write_MASTER_CTL(iface,
 224                                         read_MASTER_CTL(iface) & ~RSTART);
 225                 } else {
 226                         iface->result = 1;
 227                         write_INT_MASK(iface, 0);
 228                         write_MASTER_CTL(iface, 0);
 229                 }
 230                 complete(&iface->complete);
 231         }
 232 }
 233
 234 /* Interrupt handler */
 235 static irqreturn_t bfin_twi_interrupt_entry(int irq, void *dev_id)
 236 {
 237         struct bfin_twi_iface *iface = dev_id;
 238         unsigned long flags;
 239         unsigned short twi_int_status;
 240
 241         spin_lock_irqsave(&iface->lock, flags);
 242         while (1) {
 243                 twi_int_status = read_INT_STAT(iface);
 244                 if (!twi_int_status)
 245                         break;
 246                 /* Clear interrupt status */
 247                 write_INT_STAT(iface, twi_int_status);
 248                 bfin_twi_handle_interrupt(iface, twi_int_status);
 249         }
 250         spin_unlock_irqrestore(&iface->lock, flags);
 251         return IRQ_HANDLED;
 252 }
 253
 254 /*
 255  * One i2c master transfer
 256  */
 257 static int bfin_twi_do_master_xfer(struct i2c_adapter *adap,
 258                                 struct i2c_msg *msgs, int num)
 259 {
 260         struct bfin_twi_iface *iface = adap->algo_data;
 261         struct i2c_msg *pmsg;
 262         int rc = 0;
 263
 264         if (!(read_CONTROL(iface) & TWI_ENA))
 265                 return -ENXIO;
 266
 267         if (read_MASTER_STAT(iface) & BUSBUSY)
 268                 return -EAGAIN;
 269
 270         iface->pmsg = msgs;
 271         iface->msg_num = num;
 272         iface->cur_msg = 0;
 273
 274         pmsg = &msgs[0];
 275         if (pmsg->flags & I2C_M_TEN) {
 276                 dev_err(&adap->dev, "10 bits addr not supported!\n");
 277                 return -EINVAL;
 278         }
 279
 280         if (iface->msg_num > 1)
 281                 iface->cur_mode = TWI_I2C_MODE_REPEAT;
 282         iface->manual_stop = 0;
 283         iface->transPtr = pmsg->buf;
 284         iface->writeNum = iface->readNum = pmsg->len;
 285         iface->result = 0;
 286         init_completion(&(iface->complete));
 287         /* Set Transmit device address */
 288         write_MASTER_ADDR(iface, pmsg->addr);
 289
 290         /* FIFO Initiation. Data in FIFO should be
 291          *  discarded before start a new operation.
 292          */
 293         write_FIFO_CTL(iface, 0x3);
 294         write_FIFO_CTL(iface, 0);
 295
 296         if (pmsg->flags & I2C_M_RD)
 297                 iface->read_write = I2C_SMBUS_READ;
 298         else {
 299                 iface->read_write = I2C_SMBUS_WRITE;
 300                 /* Transmit first data */
 301                 if (iface->writeNum > 0) {
 302                         write_XMT_DATA8(iface, *(iface->transPtr++));
 303                         iface->writeNum--;
 304                 }
 305         }
 306
 307         /* clear int stat */
 308         write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
 309
 310         /* Interrupt mask . Enable XMT, RCV interrupt */
 311         write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
 312
 313         if (pmsg->len <= 255)
 314                 write_MASTER_CTL(iface, pmsg->len << 6);
 315         else {
 316                 write_MASTER_CTL(iface, 0xff << 6);
 317                 iface->manual_stop = 1;
 318         }
 319
 320         /* Master enable */
 321         write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 322                 (iface->msg_num > 1 ? RSTART : 0) |
 323                 ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
 324                 ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
 325
 326         while (!iface->result) {
 327                 if (!wait_for_completion_timeout(&iface->complete,
 328                         adap->timeout)) {
 329                         iface->result = -1;
 330                         dev_err(&adap->dev, "master transfer timeout\n");
 331                 }
 332         }
 333
 334         if (iface->result == 1)
 335                 rc = iface->cur_msg + 1;
 336         else
 337                 rc = iface->result;
 338
 339         return rc;
 340 }
 341
 342 /*
 343  * Generic i2c master transfer entrypoint
 344  */
 345 static int bfin_twi_master_xfer(struct i2c_adapter *adap,
 346                                 struct i2c_msg *msgs, int num)
 347 {
 348         return bfin_twi_do_master_xfer(adap, msgs, num);
 349 }
 350
 351 /*
 352  * One I2C SMBus transfer
 353  */
 354 int bfin_twi_do_smbus_xfer(struct i2c_adapter *adap, u16 addr,
 355                         unsigned short flags, char read_write,
 356                         u8 command, int size, union i2c_smbus_data *data)
 357 {
 358         struct bfin_twi_iface *iface = adap->algo_data;
 359         int rc = 0;
 360
 361         if (!(read_CONTROL(iface) & TWI_ENA))
 362                 return -ENXIO;
 363
 364         if (read_MASTER_STAT(iface) & BUSBUSY)
 365                 return -EAGAIN;
 366
 367         iface->writeNum = 0;
 368         iface->readNum = 0;
 369
 370         /* Prepare datas & select mode */
 371         switch (size) {
 372         case I2C_SMBUS_QUICK:
 373                 iface->transPtr = NULL;
 374                 iface->cur_mode = TWI_I2C_MODE_STANDARD;
 375                 break;
 376         case I2C_SMBUS_BYTE:
 377                 if (data == NULL)
 378                         iface->transPtr = NULL;
 379                 else {
 380                         if (read_write == I2C_SMBUS_READ)
 381                                 iface->readNum = 1;
 382                         else
 383                                 iface->writeNum = 1;
 384                         iface->transPtr = &data->byte;
 385                 }
 386                 iface->cur_mode = TWI_I2C_MODE_STANDARD;
 387                 break;
 388         case I2C_SMBUS_BYTE_DATA:
 389                 if (read_write == I2C_SMBUS_READ) {
 390                         iface->readNum = 1;
 391                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 392                 } else {
 393                         iface->writeNum = 1;
 394                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 395                 }
 396                 iface->transPtr = &data->byte;
 397                 break;
 398         case I2C_SMBUS_WORD_DATA:
 399                 if (read_write == I2C_SMBUS_READ) {
 400                         iface->readNum = 2;
 401                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 402                 } else {
 403                         iface->writeNum = 2;
 404                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 405                 }
 406                 iface->transPtr = (u8 *)&data->word;
 407                 break;
 408         case I2C_SMBUS_PROC_CALL:
 409                 iface->writeNum = 2;
 410                 iface->readNum = 2;
 411                 iface->cur_mode = TWI_I2C_MODE_COMBINED;
 412                 iface->transPtr = (u8 *)&data->word;
 413                 break;
 414         case I2C_SMBUS_BLOCK_DATA:
 415                 if (read_write == I2C_SMBUS_READ) {
 416                         iface->readNum = 0;
 417                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 418                 } else {
 419                         iface->writeNum = data->block[0] + 1;
 420                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 421                 }
 422                 iface->transPtr = data->block;
 423                 break;
 424         case I2C_SMBUS_I2C_BLOCK_DATA:
 425                 if (read_write == I2C_SMBUS_READ) {
 426                         iface->readNum = data->block[0];
 427                         iface->cur_mode = TWI_I2C_MODE_COMBINED;
 428                 } else {
 429                         iface->writeNum = data->block[0];
 430                         iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
 431                 }
 432                 iface->transPtr = (u8 *)&data->block[1];
 433                 break;
 434         default:
 435                 return -1;
 436         }
 437
 438         iface->result = 0;
 439         iface->manual_stop = 0;
 440         iface->read_write = read_write;
 441         iface->command = command;
 442         init_completion(&(iface->complete));
 443
 444         /* FIFO Initiation. Data in FIFO should be discarded before
 445          * start a new operation.
 446          */
 447         write_FIFO_CTL(iface, 0x3);
 448         write_FIFO_CTL(iface, 0);
 449
 450         /* clear int stat */
 451         write_INT_STAT(iface, MERR | MCOMP | XMTSERV | RCVSERV);
 452
 453         /* Set Transmit device address */
 454         write_MASTER_ADDR(iface, addr);
 455
 456         switch (iface->cur_mode) {
 457         case TWI_I2C_MODE_STANDARDSUB:
 458                 write_XMT_DATA8(iface, iface->command);
 459                 write_INT_MASK(iface, MCOMP | MERR |
 460                         ((iface->read_write == I2C_SMBUS_READ) ?
 461                         RCVSERV : XMTSERV));
 462
 463                 if (iface->writeNum + 1 <= 255)
 464                         write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
 465                 else {
 466                         write_MASTER_CTL(iface, 0xff << 6);
 467                         iface->manual_stop = 1;
 468                 }
 469                 /* Master enable */
 470                 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 471                         ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
 472                 break;
 473         case TWI_I2C_MODE_COMBINED:
 474                 write_XMT_DATA8(iface, iface->command);
 475                 write_INT_MASK(iface, MCOMP | MERR | RCVSERV | XMTSERV);
 476
 477                 if (iface->writeNum > 0)
 478                         write_MASTER_CTL(iface, (iface->writeNum + 1) << 6);
 479                 else
 480                         write_MASTER_CTL(iface, 0x1 << 6);
 481                 /* Master enable */
 482                 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN | RSTART |
 483                         ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ>100) ? FAST : 0));
 484                 break;
 485         default:
 486                 write_MASTER_CTL(iface, 0);
 487                 if (size != I2C_SMBUS_QUICK) {
 488                         /* Don't access xmit data register when this is a
 489                          * read operation.
 490                          */
 491                         if (iface->read_write != I2C_SMBUS_READ) {
 492                                 if (iface->writeNum > 0) {
 493                                         write_XMT_DATA8(iface,
 494                                                 *(iface->transPtr++));
 495                                         if (iface->writeNum <= 255)
 496                                                 write_MASTER_CTL(iface,
 497                                                         iface->writeNum << 6);
 498                                         else {
 499                                                 write_MASTER_CTL(iface,
 500                                                         0xff << 6);
 501                                                 iface->manual_stop = 1;
 502                                         }
 503                                         iface->writeNum--;
 504                                 } else {
 505                                         write_XMT_DATA8(iface, iface->command);
 506                                         write_MASTER_CTL(iface, 1 << 6);
 507                                 }
 508                         } else {
 509                                 if (iface->readNum > 0 && iface->readNum <= 255)
 510                                         write_MASTER_CTL(iface,
 511                                                 iface->readNum << 6);
 512                                 else if (iface->readNum > 255) {
 513                                         write_MASTER_CTL(iface, 0xff << 6);
 514                                         iface->manual_stop = 1;
 515                                 } else
 516                                         break;
 517                         }
 518                 }
 519                 write_INT_MASK(iface, MCOMP | MERR |
 520                         ((iface->read_write == I2C_SMBUS_READ) ?
 521                         RCVSERV : XMTSERV));
 522
 523                 /* Master enable */
 524                 write_MASTER_CTL(iface, read_MASTER_CTL(iface) | MEN |
 525                         ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
 526                         ((CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ > 100) ? FAST : 0));
 527                 break;
 528         }
 529
 530         while (!iface->result) {
 531                 if (!wait_for_completion_timeout(&iface->complete,
 532                         adap->timeout)) {
 533                         iface->result = -1;
 534                         dev_err(&adap->dev, "smbus transfer timeout\n");
 535                 }
 536         }
 537
 538         rc = (iface->result >= 0) ? 0 : -1;
 539
 540         return rc;
 541 }
 542
 543 /*
 544  * Generic I2C SMBus transfer entrypoint
 545  */
 546 int bfin_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
 547                         unsigned short flags, char read_write,
 548                         u8 command, int size, union i2c_smbus_data *data)
 549 {
 550         return bfin_twi_do_smbus_xfer(adap, addr, flags,
 551                         read_write, command, size, data);
 552 }
 553
 554 /*
 555  * Return what the adapter supports
 556  */
 557 static u32 bfin_twi_functionality(struct i2c_adapter *adap)
 558 {
 559         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 560                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 561                I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
 562                I2C_FUNC_I2C | I2C_FUNC_SMBUS_I2C_BLOCK;
 563 }
 564
 565 static const struct i2c_algorithm bfin_twi_algorithm = {
 566         .master_xfer   = bfin_twi_master_xfer,
 567         .smbus_xfer    = bfin_twi_smbus_xfer,
 568         .functionality = bfin_twi_functionality,
 569 };
 570
 571 #ifdef CONFIG_PM_SLEEP
 572 static int i2c_bfin_twi_suspend(struct device *dev)
 573 {
 574         struct bfin_twi_iface *iface = dev_get_drvdata(dev);
 575
 576         iface->saved_clkdiv = read_CLKDIV(iface);
 577         iface->saved_control = read_CONTROL(iface);
 578
 579         free_irq(iface->irq, iface);
 580
 581         /* Disable TWI */
 582         write_CONTROL(iface, iface->saved_control & ~TWI_ENA);
 583
 584         return 0;
 585 }
 586
 587 static int i2c_bfin_twi_resume(struct device *dev)
 588 {
 589         struct bfin_twi_iface *iface = dev_get_drvdata(dev);
 590
 591         int rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
 592                 0, to_platform_device(dev)->name, iface);
 593         if (rc) {
 594                 dev_err(dev, "Can't get IRQ %d !\n", iface->irq);
 595                 return -ENODEV;
 596         }
 597
 598         /* Resume TWI interface clock as specified */
 599         write_CLKDIV(iface, iface->saved_clkdiv);
 600
 601         /* Resume TWI */
 602         write_CONTROL(iface, iface->saved_control);
 603
 604         return 0;
 605 }
 606
 607 static SIMPLE_DEV_PM_OPS(i2c_bfin_twi_pm,
 608                          i2c_bfin_twi_suspend, i2c_bfin_twi_resume);
 609 #define I2C_BFIN_TWI_PM_OPS     (&i2c_bfin_twi_pm)
 610 #else
 611 #define I2C_BFIN_TWI_PM_OPS     NULL
 612 #endif
 613
 614 static int i2c_bfin_twi_probe(struct platform_device *pdev)
 615 {
 616         struct bfin_twi_iface *iface;
 617         struct i2c_adapter *p_adap;
 618         struct resource *res;
 619         int rc;
 620         unsigned int clkhilow;
 621
 622         iface = devm_kzalloc(&pdev->dev, sizeof(struct bfin_twi_iface),
 623                         GFP_KERNEL);
 624         if (!iface) {
 625                 dev_err(&pdev->dev, "Cannot allocate memory\n");
 626                 return -ENOMEM;
 627         }
 628
 629         spin_lock_init(&(iface->lock));
 630
 631         /* Find and map our resources */
 632         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 633         iface->regs_base = devm_ioremap_resource(&pdev->dev, res);
 634         if (IS_ERR(iface->regs_base)) {
 635                 dev_err(&pdev->dev, "Cannot map IO\n");
 636                 return PTR_ERR(iface->regs_base);
 637         }
 638
 639         iface->irq = platform_get_irq(pdev, 0);
 640         if (iface->irq < 0) {
 641                 dev_err(&pdev->dev, "No IRQ specified\n");
 642                 return -ENOENT;
 643         }
 644
 645         p_adap = &iface->adap;
 646         p_adap->nr = pdev->id;
 647         strlcpy(p_adap->name, pdev->name, sizeof(p_adap->name));
 648         p_adap->algo = &bfin_twi_algorithm;
 649         p_adap->algo_data = iface;
 650         p_adap->class = I2C_CLASS_DEPRECATED;
 651         p_adap->dev.parent = &pdev->dev;
 652         p_adap->timeout = 5 * HZ;
 653         p_adap->retries = 3;
 654
 655         rc = peripheral_request_list(
 656                         dev_get_platdata(&pdev->dev),
 657                         "i2c-bfin-twi");
 658         if (rc) {
 659                 dev_err(&pdev->dev, "Can't setup pin mux!\n");
 660                 return -EBUSY;
 661         }
 662
 663         rc = devm_request_irq(&pdev->dev, iface->irq, bfin_twi_interrupt_entry,
 664                 0, pdev->name, iface);
 665         if (rc) {
 666                 dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
 667                 rc = -ENODEV;
 668                 goto out_error;
 669         }
 670
 671         /* Set TWI internal clock as 10MHz */
 672         write_CONTROL(iface, ((get_sclk() / 1000 / 1000 + 5) / 10) & 0x7F);
 673
 674         /*
 675          * We will not end up with a CLKDIV=0 because no one will specify
 676          * 20kHz SCL or less in Kconfig now. (5 * 1000 / 20 = 250)
 677          */
 678         clkhilow = ((10 * 1000 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ) + 1) / 2;
 679
 680         /* Set Twi interface clock as specified */
 681         write_CLKDIV(iface, (clkhilow << 8) | clkhilow);
 682
 683         /* Enable TWI */
 684         write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
 685
 686         rc = i2c_add_numbered_adapter(p_adap);
 687         if (rc < 0)
 688                 goto out_error;
 689
 690         platform_set_drvdata(pdev, iface);
 691
 692         dev_info(&pdev->dev, "Blackfin BF5xx on-chip I2C TWI Controller, "
 693                 "regs_base@%p\n", iface->regs_base);
 694
 695         return 0;
 696
 697 out_error:
 698         peripheral_free_list(dev_get_platdata(&pdev->dev));
 699         return rc;
 700 }
 701
 702 static int i2c_bfin_twi_remove(struct platform_device *pdev)
 703 {
 704         struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
 705
 706         i2c_del_adapter(&(iface->adap));
 707         peripheral_free_list(dev_get_platdata(&pdev->dev));
 708
 709         return 0;
 710 }
 711
 712 static struct platform_driver i2c_bfin_twi_driver = {
 713         .probe          = i2c_bfin_twi_probe,
 714         .remove         = i2c_bfin_twi_remove,
 715         .driver         = {
 716                 .name   = "i2c-bfin-twi",
 717                 .pm     = I2C_BFIN_TWI_PM_OPS,
 718         },
 719 };
 720
 721 static int __init i2c_bfin_twi_init(void)
 722 {
 723         return platform_driver_register(&i2c_bfin_twi_driver);
 724 }
 725
 726 static void __exit i2c_bfin_twi_exit(void)
 727 {
 728         platform_driver_unregister(&i2c_bfin_twi_driver);
 729 }
 730
 731 subsys_initcall(i2c_bfin_twi_init);
 732 module_exit(i2c_bfin_twi_exit);
 733
 734 MODULE_AUTHOR("Bryan Wu, Sonic Zhang");
 735 MODULE_DESCRIPTION("Blackfin BF5xx on-chip I2C TWI Controller Driver");
 736 MODULE_LICENSE("GPL");
 737 MODULE_ALIAS("platform:i2c-bfin-twi");