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 = -ENODEV;
 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                 goto exit;
 159         }
 160
 161         retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 162                                    ali1535_driver.name);
 163         if (retval)
 164                 goto exit;
 165
 166         if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 167                             ali1535_driver.name)) {
 168                 dev_err(&dev->dev, "ALI1535_smb region 0x%x already in use!\n",
 169                         ali1535_smba);
 170                 goto exit;
 171         }
 172
 173         /* check if whole device is enabled */
 174         pci_read_config_byte(dev, SMBCFG, &temp);
 175         if ((temp & ALI1535_SMBIO_EN) == 0) {
 176                 dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
 177                 goto exit_free;
 178         }
 179
 180         /* Is SMB Host controller enabled? */
 181         pci_read_config_byte(dev, SMBHSTCFG, &temp);
 182         if ((temp & 1) == 0) {
 183                 dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
 184                 goto exit_free;
 185         }
 186
 187         /* set SMB clock to 74KHz as recommended in data sheet */
 188         pci_write_config_byte(dev, SMBCLK, 0x20);
 189
 190         /*
 191           The interrupt routing for SMB is set up in register 0x77 in the
 192           1533 ISA Bridge device, NOT in the 7101 device.
 193           Don't bother with finding the 1533 device and reading the register.
 194         if ((....... & 0x0F) == 1)
 195                 dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
 196         */
 197         pci_read_config_byte(dev, SMBREV, &temp);
 198         dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
 199         dev_dbg(&dev->dev, "ALI1535_smba = 0x%X\n", ali1535_smba);
 200
 201         retval = 0;
 202 exit:
 203         return retval;
 204
 205 exit_free:
 206         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 207         return retval;
 208 }
 209
 210 static int ali1535_transaction(struct i2c_adapter *adap)
 211 {
 212         int temp;
 213         int result = 0;
 214         int timeout = 0;
 215
 216         dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
 217                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 218                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 219                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 220
 221         /* get status */
 222         temp = inb_p(SMBHSTSTS);
 223
 224         /* Make sure the SMBus host is ready to start transmitting */
 225         /* Check the busy bit first */
 226         if (temp & ALI1535_STS_BUSY) {
 227                 /* If the host controller is still busy, it may have timed out
 228                  * in the previous transaction, resulting in a "SMBus Timeout"
 229                  * printk.  I've tried the following to reset a stuck busy bit.
 230                  *   1. Reset the controller with an KILL command. (this
 231                  *      doesn't seem to clear the controller if an external
 232                  *      device is hung)
 233                  *   2. Reset the controller and the other SMBus devices with a
 234                  *      T_OUT command. (this clears the host busy bit if an
 235                  *      external device is hung, but it comes back upon a new
 236                  *      access to a device)
 237                  *   3. Disable and reenable the controller in SMBHSTCFG. Worst
 238                  *      case, nothing seems to work except power reset.
 239                  */
 240
 241                 /* Try resetting entire SMB bus, including other devices - This
 242                  * may not work either - it clears the BUSY bit but then the
 243                  * BUSY bit may come back on when you try and use the chip
 244                  * again.  If that's the case you are stuck.
 245                  */
 246                 dev_info(&adap->dev,
 247                         "Resetting entire SMB Bus to clear busy condition (%02x)\n",
 248                         temp);
 249                 outb_p(ALI1535_T_OUT, SMBHSTTYP);
 250                 temp = inb_p(SMBHSTSTS);
 251         }
 252
 253         /* now check the error bits and the busy bit */
 254         if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 255                 /* do a clear-on-write */
 256                 outb_p(0xFF, SMBHSTSTS);
 257                 if ((temp = inb_p(SMBHSTSTS)) &
 258                     (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 259                         /* This is probably going to be correctable only by a
 260                          * power reset as one of the bits now appears to be
 261                          * stuck */
 262                         /* This may be a bus or device with electrical problems. */
 263                         dev_err(&adap->dev,
 264                                 "SMBus reset failed! (0x%02x) - controller or "
 265                                 "device on bus is probably hung\n", temp);
 266                         return -EBUSY;
 267                 }
 268         } else {
 269                 /* check and clear done bit */
 270                 if (temp & ALI1535_STS_DONE) {
 271                         outb_p(temp, SMBHSTSTS);
 272                 }
 273         }
 274
 275         /* start the transaction by writing anything to the start register */
 276         outb_p(0xFF, SMBHSTPORT);
 277
 278         /* We will always wait for a fraction of a second! */
 279         timeout = 0;
 280         do {
 281                 msleep(1);
 282                 temp = inb_p(SMBHSTSTS);
 283         } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
 284                  && (timeout++ < MAX_TIMEOUT));
 285
 286         /* If the SMBus is still busy, we give up */
 287         if (timeout > MAX_TIMEOUT) {
 288                 result = -ETIMEDOUT;
 289                 dev_err(&adap->dev, "SMBus Timeout!\n");
 290         }
 291
 292         if (temp & ALI1535_STS_FAIL) {
 293                 result = -EIO;
 294                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 295         }
 296
 297         /* Unfortunately the ALI SMB controller maps "no response" and "bus
 298          * collision" into a single bit. No response is the usual case so don't
 299          * do a printk.  This means that bus collisions go unreported.
 300          */
 301         if (temp & ALI1535_STS_BUSERR) {
 302                 result = -ENXIO;
 303                 dev_dbg(&adap->dev,
 304                         "Error: no response or bus collision ADD=%02x\n",
 305                         inb_p(SMBHSTADD));
 306         }
 307
 308         /* haven't ever seen this */
 309         if (temp & ALI1535_STS_DEV) {
 310                 result = -EIO;
 311                 dev_err(&adap->dev, "Error: device error\n");
 312         }
 313
 314         /* check to see if the "command complete" indication is set */
 315         if (!(temp & ALI1535_STS_DONE)) {
 316                 result = -ETIMEDOUT;
 317                 dev_err(&adap->dev, "Error: command never completed\n");
 318         }
 319
 320         dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
 321                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 322                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 323                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 324
 325         /* take consequent actions for error conditions */
 326         if (!(temp & ALI1535_STS_DONE)) {
 327                 /* issue "kill" to reset host controller */
 328                 outb_p(ALI1535_KILL,SMBHSTTYP);
 329                 outb_p(0xFF,SMBHSTSTS);
 330         } else if (temp & ALI1535_STS_ERR) {
 331                 /* issue "timeout" to reset all devices on bus */
 332                 outb_p(ALI1535_T_OUT,SMBHSTTYP);
 333                 outb_p(0xFF,SMBHSTSTS);
 334         }
 335
 336         return result;
 337 }
 338
 339 /* Return negative errno on error. */
 340 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 341                           unsigned short flags, char read_write, u8 command,
 342                           int size, union i2c_smbus_data *data)
 343 {
 344         int i, len;
 345         int temp;
 346         int timeout;
 347         s32 result = 0;
 348
 349         /* make sure SMBus is idle */
 350         temp = inb_p(SMBHSTSTS);
 351         for (timeout = 0;
 352              (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
 353              timeout++) {
 354                 msleep(1);
 355                 temp = inb_p(SMBHSTSTS);
 356         }
 357         if (timeout >= MAX_TIMEOUT)
 358                 dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 359
 360         /* clear status register (clear-on-write) */
 361         outb_p(0xFF, SMBHSTSTS);
 362
 363         switch (size) {
 364         case I2C_SMBUS_QUICK:
 365                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 366                        SMBHSTADD);
 367                 size = ALI1535_QUICK;
 368                 outb_p(size, SMBHSTTYP);        /* output command */
 369                 break;
 370         case I2C_SMBUS_BYTE:
 371                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 372                        SMBHSTADD);
 373                 size = ALI1535_BYTE;
 374                 outb_p(size, SMBHSTTYP);        /* output command */
 375                 if (read_write == I2C_SMBUS_WRITE)
 376                         outb_p(command, SMBHSTCMD);
 377                 break;
 378         case I2C_SMBUS_BYTE_DATA:
 379                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 380                        SMBHSTADD);
 381                 size = ALI1535_BYTE_DATA;
 382                 outb_p(size, SMBHSTTYP);        /* output command */
 383                 outb_p(command, SMBHSTCMD);
 384                 if (read_write == I2C_SMBUS_WRITE)
 385                         outb_p(data->byte, SMBHSTDAT0);
 386                 break;
 387         case I2C_SMBUS_WORD_DATA:
 388                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 389                        SMBHSTADD);
 390                 size = ALI1535_WORD_DATA;
 391                 outb_p(size, SMBHSTTYP);        /* output command */
 392                 outb_p(command, SMBHSTCMD);
 393                 if (read_write == I2C_SMBUS_WRITE) {
 394                         outb_p(data->word & 0xff, SMBHSTDAT0);
 395                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 396                 }
 397                 break;
 398         case I2C_SMBUS_BLOCK_DATA:
 399                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 400                        SMBHSTADD);
 401                 size = ALI1535_BLOCK_DATA;
 402                 outb_p(size, SMBHSTTYP);        /* output command */
 403                 outb_p(command, SMBHSTCMD);
 404                 if (read_write == I2C_SMBUS_WRITE) {
 405                         len = data->block[0];
 406                         if (len < 0) {
 407                                 len = 0;
 408                                 data->block[0] = len;
 409                         }
 410                         if (len > 32) {
 411                                 len = 32;
 412                                 data->block[0] = len;
 413                         }
 414                         outb_p(len, SMBHSTDAT0);
 415                         /* Reset SMBBLKDAT */
 416                         outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 417                         for (i = 1; i <= len; i++)
 418                                 outb_p(data->block[i], SMBBLKDAT);
 419                 }
 420                 break;
 421         default:
 422                 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 423                 result = -EOPNOTSUPP;
 424                 goto EXIT;
 425         }
 426
 427         result = ali1535_transaction(adap);
 428         if (result)
 429                 goto EXIT;
 430
 431         if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
 432                 result = 0;
 433                 goto EXIT;
 434         }
 435
 436         switch (size) {
 437         case ALI1535_BYTE:      /* Result put in SMBHSTDAT0 */
 438                 data->byte = inb_p(SMBHSTDAT0);
 439                 break;
 440         case ALI1535_BYTE_DATA:
 441                 data->byte = inb_p(SMBHSTDAT0);
 442                 break;
 443         case ALI1535_WORD_DATA:
 444                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 445                 break;
 446         case ALI1535_BLOCK_DATA:
 447                 len = inb_p(SMBHSTDAT0);
 448                 if (len > 32)
 449                         len = 32;
 450                 data->block[0] = len;
 451                 /* Reset SMBBLKDAT */
 452                 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 453                 for (i = 1; i <= data->block[0]; i++) {
 454                         data->block[i] = inb_p(SMBBLKDAT);
 455                         dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 456                                 len, i, data->block[i]);
 457                 }
 458                 break;
 459         }
 460 EXIT:
 461         return result;
 462 }
 463
 464
 465 static u32 ali1535_func(struct i2c_adapter *adapter)
 466 {
 467         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 468             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 469             I2C_FUNC_SMBUS_BLOCK_DATA;
 470 }
 471
 472 static const struct i2c_algorithm smbus_algorithm = {
 473         .smbus_xfer     = ali1535_access,
 474         .functionality  = ali1535_func,
 475 };
 476
 477 static struct i2c_adapter ali1535_adapter = {
 478         .owner          = THIS_MODULE,
 479         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 480         .algo           = &smbus_algorithm,
 481 };
 482
 483 static const struct pci_device_id ali1535_ids[] = {
 484         { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 485         { },
 486 };
 487
 488 MODULE_DEVICE_TABLE (pci, ali1535_ids);
 489
 490 static int __devinit ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
 491 {
 492         if (ali1535_setup(dev)) {
 493                 dev_warn(&dev->dev,
 494                         "ALI1535 not detected, module not inserted.\n");
 495                 return -ENODEV;
 496         }
 497
 498         /* set up the sysfs linkage to our parent device */
 499         ali1535_adapter.dev.parent = &dev->dev;
 500
 501         snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
 502                 "SMBus ALI1535 adapter at %04x", ali1535_smba);
 503         return i2c_add_adapter(&ali1535_adapter);
 504 }
 505
 506 static void __devexit ali1535_remove(struct pci_dev *dev)
 507 {
 508         i2c_del_adapter(&ali1535_adapter);
 509         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 510 }
 511
 512 static struct pci_driver ali1535_driver = {
 513         .name           = "ali1535_smbus",
 514         .id_table       = ali1535_ids,
 515         .probe          = ali1535_probe,
 516         .remove         = __devexit_p(ali1535_remove),
 517 };
 518
 519 static int __init i2c_ali1535_init(void)
 520 {
 521         return pci_register_driver(&ali1535_driver);
 522 }
 523
 524 static void __exit i2c_ali1535_exit(void)
 525 {
 526         pci_unregister_driver(&ali1535_driver);
 527 }
 528
 529 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 530               "Philip Edelbrock <phil@netroedge.com>, "
 531               "Mark D. Studebaker <mdsxyz123@yahoo.com> "
 532               "and Dan Eaton <dan.eaton@rocketlogix.com>");
 533 MODULE_DESCRIPTION("ALI1535 SMBus driver");
 534 MODULE_LICENSE("GPL");
 535
 536 module_init(i2c_ali1535_init);
 537 module_exit(i2c_ali1535_exit);