drivers/i2c/busses/i2c-ali1535.c

   1 /*
   2     Copyright (c) 2000  Frodo Looijaard <frodol@dds.nl>,
   3                         Philip Edelbrock <phil@netroedge.com>,
   4                         Mark D. Studebaker <mdsxyz123@yahoo.com>,
   5                         Dan Eaton <dan.eaton@rocketlogix.com> and
   6                         Stephen Rousset<stephen.rousset@rocketlogix.com>
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 /*
  24     This is the driver for the SMB Host controller on
  25     Acer Labs Inc. (ALI) M1535 South Bridge.
  26
  27     The M1535 is a South bridge for portable systems.
  28     It is very similar to the M15x3 South bridges also produced
  29     by Acer Labs Inc.  Some of the registers within the part
  30     have moved and some have been redefined slightly. Additionally,
  31     the sequencing of the SMBus transactions has been modified
  32     to be more consistent with the sequencing recommended by
  33     the manufacturer and observed through testing.  These
  34     changes are reflected in this driver and can be identified
  35     by comparing this driver to the i2c-ali15x3 driver.
  36     For an overview of these chips see http://www.acerlabs.com
  37
  38     The SMB controller is part of the 7101 device, which is an
  39     ACPI-compliant Power Management Unit (PMU).
  40
  41     The whole 7101 device has to be enabled for the SMB to work.
  42     You can't just enable the SMB alone.
  43     The SMB and the ACPI have separate I/O spaces.
  44     We make sure that the SMB is enabled. We leave the ACPI alone.
  45
  46     This driver controls the SMB Host only.
  47
  48     This driver does not use interrupts.
  49 */
  50
  51
  52 /* Note: we assume there can only be one ALI1535, with one SMBus interface */
  53
  54 #include <linux/module.h>
  55 #include <linux/pci.h>
  56 #include <linux/kernel.h>
  57 #include <linux/stddef.h>
  58 #include <linux/delay.h>
  59 #include <linux/ioport.h>
  60 #include <linux/i2c.h>
  61 #include <linux/init.h>
  62 #include <linux/acpi.h>
  63 #include <linux/io.h>
  64
  65
  66 /* ALI1535 SMBus address offsets */
  67 #define SMBHSTSTS       (0 + ali1535_smba)
  68 #define SMBHSTTYP       (1 + ali1535_smba)
  69 #define SMBHSTPORT      (2 + ali1535_smba)
  70 #define SMBHSTCMD       (7 + ali1535_smba)
  71 #define SMBHSTADD       (3 + ali1535_smba)
  72 #define SMBHSTDAT0      (4 + ali1535_smba)
  73 #define SMBHSTDAT1      (5 + ali1535_smba)
  74 #define SMBBLKDAT       (6 + ali1535_smba)
  75
  76 /* PCI Address Constants */
  77 #define SMBCOM          0x004
  78 #define SMBREV          0x008
  79 #define SMBCFG          0x0D1
  80 #define SMBBA           0x0E2
  81 #define SMBHSTCFG       0x0F0
  82 #define SMBCLK          0x0F2
  83
  84 /* Other settings */
  85 #define MAX_TIMEOUT             500     /* times 1/100 sec */
  86 #define ALI1535_SMB_IOSIZE      32
  87
  88 #define ALI1535_SMB_DEFAULTBASE 0x8040
  89
  90 /* ALI1535 address lock bits */
  91 #define ALI1535_LOCK            0x06    /* dwe */
  92
  93 /* ALI1535 command constants */
  94 #define ALI1535_QUICK           0x00
  95 #define ALI1535_BYTE            0x10
  96 #define ALI1535_BYTE_DATA       0x20
  97 #define ALI1535_WORD_DATA       0x30
  98 #define ALI1535_BLOCK_DATA      0x40
  99 #define ALI1535_I2C_READ        0x60
 100
 101 #define ALI1535_DEV10B_EN       0x80    /* Enable 10-bit addressing in  */
 102                                         /*  I2C read                    */
 103 #define ALI1535_T_OUT           0x08    /* Time-out Command (write)     */
 104 #define ALI1535_A_HIGH_BIT9     0x08    /* Bit 9 of 10-bit address in   */
 105                                         /* Alert-Response-Address       */
 106                                         /* (read)                       */
 107 #define ALI1535_KILL            0x04    /* Kill Command (write)         */
 108 #define ALI1535_A_HIGH_BIT8     0x04    /* Bit 8 of 10-bit address in   */
 109                                         /*  Alert-Response-Address      */
 110                                         /*  (read)                      */
 111
 112 #define ALI1535_D_HI_MASK       0x03    /* Mask for isolating bits 9-8  */
 113                                         /*  of 10-bit address in I2C    */
 114                                         /*  Read Command                */
 115
 116 /* ALI1535 status register bits */
 117 #define ALI1535_STS_IDLE        0x04
 118 #define ALI1535_STS_BUSY        0x08    /* host busy */
 119 #define ALI1535_STS_DONE        0x10    /* transaction complete */
 120 #define ALI1535_STS_DEV         0x20    /* device error */
 121 #define ALI1535_STS_BUSERR      0x40    /* bus error    */
 122 #define ALI1535_STS_FAIL        0x80    /* failed bus transaction */
 123 #define ALI1535_STS_ERR         0xE0    /* all the bad error bits */
 124
 125 #define ALI1535_BLOCK_CLR       0x04    /* reset block data index */
 126
 127 /* ALI1535 device address register bits */
 128 #define ALI1535_RD_ADDR         0x01    /* Read/Write Bit in Device     */
 129                                         /*  Address field               */
 130                                         /*  -> Write = 0                */
 131                                         /*  -> Read  = 1                */
 132 #define ALI1535_SMBIO_EN        0x04    /* SMB I/O Space enable         */
 133
 134 static struct pci_driver ali1535_driver;
 135 static unsigned short ali1535_smba;
 136
 137 /* Detect whether a ALI1535 can be found, and initialize it, where necessary.
 138    Note the differences between kernels with the old PCI BIOS interface and
 139    newer kernels with the real PCI interface. In compat.h some things are
 140    defined to make the transition easier. */
 141 static int __devinit ali1535_setup(struct pci_dev *dev)
 142 {
 143         int retval;
 144         unsigned char temp;
 145
 146         /* Check the following things:
 147                 - SMB I/O address is initialized
 148                 - Device is enabled
 149                 - We can use the addresses
 150         */
 151
 152         /* Determine the address of the SMBus area */
 153         pci_read_config_word(dev, SMBBA, &ali1535_smba);
 154         ali1535_smba &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
 155         if (ali1535_smba == 0) {
 156                 dev_warn(&dev->dev,
 157                         "ALI1535_smb region uninitialized - upgrade BIOS?\n");
 158                 retval = -ENODEV;
 159                 goto exit;
 160         }
 161
 162         retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 163                                    ali1535_driver.name);
 164         if (retval)
 165                 goto exit;
 166
 167         if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 168                             ali1535_driver.name)) {
 169                 dev_err(&dev->dev, "ALI1535_smb region 0x%x already in use!\n",
 170                         ali1535_smba);
 171                 retval = -EBUSY;
 172                 goto exit;
 173         }
 174
 175         /* check if whole device is enabled */
 176         pci_read_config_byte(dev, SMBCFG, &temp);
 177         if ((temp & ALI1535_SMBIO_EN) == 0) {
 178                 dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
 179                 retval = -ENODEV;
 180                 goto exit_free;
 181         }
 182
 183         /* Is SMB Host controller enabled? */
 184         pci_read_config_byte(dev, SMBHSTCFG, &temp);
 185         if ((temp & 1) == 0) {
 186                 dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
 187                 retval = -ENODEV;
 188                 goto exit_free;
 189         }
 190
 191         /* set SMB clock to 74KHz as recommended in data sheet */
 192         pci_write_config_byte(dev, SMBCLK, 0x20);
 193
 194         /*
 195           The interrupt routing for SMB is set up in register 0x77 in the
 196           1533 ISA Bridge device, NOT in the 7101 device.
 197           Don't bother with finding the 1533 device and reading the register.
 198         if ((....... & 0x0F) == 1)
 199                 dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
 200         */
 201         pci_read_config_byte(dev, SMBREV, &temp);
 202         dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
 203         dev_dbg(&dev->dev, "ALI1535_smba = 0x%X\n", ali1535_smba);
 204
 205         return 0;
 206
 207 exit_free:
 208         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 209 exit:
 210         return retval;
 211 }
 212
 213 static int ali1535_transaction(struct i2c_adapter *adap)
 214 {
 215         int temp;
 216         int result = 0;
 217         int timeout = 0;
 218
 219         dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
 220                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 221                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 222                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 223
 224         /* get status */
 225         temp = inb_p(SMBHSTSTS);
 226
 227         /* Make sure the SMBus host is ready to start transmitting */
 228         /* Check the busy bit first */
 229         if (temp & ALI1535_STS_BUSY) {
 230                 /* If the host controller is still busy, it may have timed out
 231                  * in the previous transaction, resulting in a "SMBus Timeout"
 232                  * printk.  I've tried the following to reset a stuck busy bit.
 233                  *   1. Reset the controller with an KILL command. (this
 234                  *      doesn't seem to clear the controller if an external
 235                  *      device is hung)
 236                  *   2. Reset the controller and the other SMBus devices with a
 237                  *      T_OUT command. (this clears the host busy bit if an
 238                  *      external device is hung, but it comes back upon a new
 239                  *      access to a device)
 240                  *   3. Disable and reenable the controller in SMBHSTCFG. Worst
 241                  *      case, nothing seems to work except power reset.
 242                  */
 243
 244                 /* Try resetting entire SMB bus, including other devices - This
 245                  * may not work either - it clears the BUSY bit but then the
 246                  * BUSY bit may come back on when you try and use the chip
 247                  * again.  If that's the case you are stuck.
 248                  */
 249                 dev_info(&adap->dev,
 250                         "Resetting entire SMB Bus to clear busy condition (%02x)\n",
 251                         temp);
 252                 outb_p(ALI1535_T_OUT, SMBHSTTYP);
 253                 temp = inb_p(SMBHSTSTS);
 254         }
 255
 256         /* now check the error bits and the busy bit */
 257         if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 258                 /* do a clear-on-write */
 259                 outb_p(0xFF, SMBHSTSTS);
 260                 if ((temp = inb_p(SMBHSTSTS)) &
 261                     (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 262                         /* This is probably going to be correctable only by a
 263                          * power reset as one of the bits now appears to be
 264                          * stuck */
 265                         /* This may be a bus or device with electrical problems. */
 266                         dev_err(&adap->dev,
 267                                 "SMBus reset failed! (0x%02x) - controller or "
 268                                 "device on bus is probably hung\n", temp);
 269                         return -EBUSY;
 270                 }
 271         } else {
 272                 /* check and clear done bit */
 273                 if (temp & ALI1535_STS_DONE) {
 274                         outb_p(temp, SMBHSTSTS);
 275                 }
 276         }
 277
 278         /* start the transaction by writing anything to the start register */
 279         outb_p(0xFF, SMBHSTPORT);
 280
 281         /* We will always wait for a fraction of a second! */
 282         timeout = 0;
 283         do {
 284                 msleep(1);
 285                 temp = inb_p(SMBHSTSTS);
 286         } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
 287                  && (timeout++ < MAX_TIMEOUT));
 288
 289         /* If the SMBus is still busy, we give up */
 290         if (timeout > MAX_TIMEOUT) {
 291                 result = -ETIMEDOUT;
 292                 dev_err(&adap->dev, "SMBus Timeout!\n");
 293         }
 294
 295         if (temp & ALI1535_STS_FAIL) {
 296                 result = -EIO;
 297                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 298         }
 299
 300         /* Unfortunately the ALI SMB controller maps "no response" and "bus
 301          * collision" into a single bit. No response is the usual case so don't
 302          * do a printk.  This means that bus collisions go unreported.
 303          */
 304         if (temp & ALI1535_STS_BUSERR) {
 305                 result = -ENXIO;
 306                 dev_dbg(&adap->dev,
 307                         "Error: no response or bus collision ADD=%02x\n",
 308                         inb_p(SMBHSTADD));
 309         }
 310
 311         /* haven't ever seen this */
 312         if (temp & ALI1535_STS_DEV) {
 313                 result = -EIO;
 314                 dev_err(&adap->dev, "Error: device error\n");
 315         }
 316
 317         /* check to see if the "command complete" indication is set */
 318         if (!(temp & ALI1535_STS_DONE)) {
 319                 result = -ETIMEDOUT;
 320                 dev_err(&adap->dev, "Error: command never completed\n");
 321         }
 322
 323         dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
 324                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 325                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 326                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 327
 328         /* take consequent actions for error conditions */
 329         if (!(temp & ALI1535_STS_DONE)) {
 330                 /* issue "kill" to reset host controller */
 331                 outb_p(ALI1535_KILL,SMBHSTTYP);
 332                 outb_p(0xFF,SMBHSTSTS);
 333         } else if (temp & ALI1535_STS_ERR) {
 334                 /* issue "timeout" to reset all devices on bus */
 335                 outb_p(ALI1535_T_OUT,SMBHSTTYP);
 336                 outb_p(0xFF,SMBHSTSTS);
 337         }
 338
 339         return result;
 340 }
 341
 342 /* Return negative errno on error. */
 343 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 344                           unsigned short flags, char read_write, u8 command,
 345                           int size, union i2c_smbus_data *data)
 346 {
 347         int i, len;
 348         int temp;
 349         int timeout;
 350         s32 result = 0;
 351
 352         /* make sure SMBus is idle */
 353         temp = inb_p(SMBHSTSTS);
 354         for (timeout = 0;
 355              (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
 356              timeout++) {
 357                 msleep(1);
 358                 temp = inb_p(SMBHSTSTS);
 359         }
 360         if (timeout >= MAX_TIMEOUT)
 361                 dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 362
 363         /* clear status register (clear-on-write) */
 364         outb_p(0xFF, SMBHSTSTS);
 365
 366         switch (size) {
 367         case I2C_SMBUS_QUICK:
 368                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 369                        SMBHSTADD);
 370                 size = ALI1535_QUICK;
 371                 outb_p(size, SMBHSTTYP);        /* output command */
 372                 break;
 373         case I2C_SMBUS_BYTE:
 374                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 375                        SMBHSTADD);
 376                 size = ALI1535_BYTE;
 377                 outb_p(size, SMBHSTTYP);        /* output command */
 378                 if (read_write == I2C_SMBUS_WRITE)
 379                         outb_p(command, SMBHSTCMD);
 380                 break;
 381         case I2C_SMBUS_BYTE_DATA:
 382                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 383                        SMBHSTADD);
 384                 size = ALI1535_BYTE_DATA;
 385                 outb_p(size, SMBHSTTYP);        /* output command */
 386                 outb_p(command, SMBHSTCMD);
 387                 if (read_write == I2C_SMBUS_WRITE)
 388                         outb_p(data->byte, SMBHSTDAT0);
 389                 break;
 390         case I2C_SMBUS_WORD_DATA:
 391                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 392                        SMBHSTADD);
 393                 size = ALI1535_WORD_DATA;
 394                 outb_p(size, SMBHSTTYP);        /* output command */
 395                 outb_p(command, SMBHSTCMD);
 396                 if (read_write == I2C_SMBUS_WRITE) {
 397                         outb_p(data->word & 0xff, SMBHSTDAT0);
 398                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 399                 }
 400                 break;
 401         case I2C_SMBUS_BLOCK_DATA:
 402                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 403                        SMBHSTADD);
 404                 size = ALI1535_BLOCK_DATA;
 405                 outb_p(size, SMBHSTTYP);        /* output command */
 406                 outb_p(command, SMBHSTCMD);
 407                 if (read_write == I2C_SMBUS_WRITE) {
 408                         len = data->block[0];
 409                         if (len < 0) {
 410                                 len = 0;
 411                                 data->block[0] = len;
 412                         }
 413                         if (len > 32) {
 414                                 len = 32;
 415                                 data->block[0] = len;
 416                         }
 417                         outb_p(len, SMBHSTDAT0);
 418                         /* Reset SMBBLKDAT */
 419                         outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 420                         for (i = 1; i <= len; i++)
 421                                 outb_p(data->block[i], SMBBLKDAT);
 422                 }
 423                 break;
 424         default:
 425                 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 426                 result = -EOPNOTSUPP;
 427                 goto EXIT;
 428         }
 429
 430         result = ali1535_transaction(adap);
 431         if (result)
 432                 goto EXIT;
 433
 434         if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
 435                 result = 0;
 436                 goto EXIT;
 437         }
 438
 439         switch (size) {
 440         case ALI1535_BYTE:      /* Result put in SMBHSTDAT0 */
 441                 data->byte = inb_p(SMBHSTDAT0);
 442                 break;
 443         case ALI1535_BYTE_DATA:
 444                 data->byte = inb_p(SMBHSTDAT0);
 445                 break;
 446         case ALI1535_WORD_DATA:
 447                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 448                 break;
 449         case ALI1535_BLOCK_DATA:
 450                 len = inb_p(SMBHSTDAT0);
 451                 if (len > 32)
 452                         len = 32;
 453                 data->block[0] = len;
 454                 /* Reset SMBBLKDAT */
 455                 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 456                 for (i = 1; i <= data->block[0]; i++) {
 457                         data->block[i] = inb_p(SMBBLKDAT);
 458                         dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 459                                 len, i, data->block[i]);
 460                 }
 461                 break;
 462         }
 463 EXIT:
 464         return result;
 465 }
 466
 467
 468 static u32 ali1535_func(struct i2c_adapter *adapter)
 469 {
 470         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 471             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 472             I2C_FUNC_SMBUS_BLOCK_DATA;
 473 }
 474
 475 static const struct i2c_algorithm smbus_algorithm = {
 476         .smbus_xfer     = ali1535_access,
 477         .functionality  = ali1535_func,
 478 };
 479
 480 static struct i2c_adapter ali1535_adapter = {
 481         .owner          = THIS_MODULE,
 482         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 483         .algo           = &smbus_algorithm,
 484 };
 485
 486 static const struct pci_device_id ali1535_ids[] = {
 487         { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 488         { },
 489 };
 490
 491 MODULE_DEVICE_TABLE (pci, ali1535_ids);
 492
 493 static int __devinit ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
 494 {
 495         if (ali1535_setup(dev)) {
 496                 dev_warn(&dev->dev,
 497                         "ALI1535 not detected, module not inserted.\n");
 498                 return -ENODEV;
 499         }
 500
 501         /* set up the sysfs linkage to our parent device */
 502         ali1535_adapter.dev.parent = &dev->dev;
 503
 504         snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
 505                 "SMBus ALI1535 adapter at %04x", ali1535_smba);
 506         return i2c_add_adapter(&ali1535_adapter);
 507 }
 508
 509 static void __devexit ali1535_remove(struct pci_dev *dev)
 510 {
 511         i2c_del_adapter(&ali1535_adapter);
 512         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 513 }
 514
 515 static struct pci_driver ali1535_driver = {
 516         .name           = "ali1535_smbus",
 517         .id_table       = ali1535_ids,
 518         .probe          = ali1535_probe,
 519         .remove         = __devexit_p(ali1535_remove),
 520 };
 521
 522 static int __init i2c_ali1535_init(void)
 523 {
 524         return pci_register_driver(&ali1535_driver);
 525 }
 526
 527 static void __exit i2c_ali1535_exit(void)
 528 {
 529         pci_unregister_driver(&ali1535_driver);
 530 }
 531
 532 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 533               "Philip Edelbrock <phil@netroedge.com>, "
 534               "Mark D. Studebaker <mdsxyz123@yahoo.com> "
 535               "and Dan Eaton <dan.eaton@rocketlogix.com>");
 536 MODULE_DESCRIPTION("ALI1535 SMBus driver");
 537 MODULE_LICENSE("GPL");
 538
 539 module_init(i2c_ali1535_init);
 540 module_exit(i2c_ali1535_exit);