drivers/i2c/busses/i2c-ali1535.c

   1 /*
   2     i2c-ali1535.c - Part of lm_sensors, Linux kernel modules for hardware
   3                     monitoring
   4     Copyright (c) 2000  Frodo Looijaard <frodol@dds.nl>,
   5                         Philip Edelbrock <phil@netroedge.com>,
   6                         Mark D. Studebaker <mdsxyz123@yahoo.com>,
   7                         Dan Eaton <dan.eaton@rocketlogix.com> and
   8                         Stephen Rousset<stephen.rousset@rocketlogix.com>
   9
  10     This program is free software; you can redistribute it and/or modify
  11     it under the terms of the GNU General Public License as published by
  12     the Free Software Foundation; either version 2 of the License, or
  13     (at your option) any later version.
  14
  15     This program is distributed in the hope that it will be useful,
  16     but WITHOUT ANY WARRANTY; without even the implied warranty of
  17     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18     GNU General Public License for more details.
  19
  20     You should have received a copy of the GNU General Public License
  21     along with this program; if not, write to the Free Software
  22     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 /*
  26     This is the driver for the SMB Host controller on
  27     Acer Labs Inc. (ALI) M1535 South Bridge.
  28
  29     The M1535 is a South bridge for portable systems.
  30     It is very similar to the M15x3 South bridges also produced
  31     by Acer Labs Inc.  Some of the registers within the part
  32     have moved and some have been redefined slightly. Additionally,
  33     the sequencing of the SMBus transactions has been modified
  34     to be more consistent with the sequencing recommended by
  35     the manufacturer and observed through testing.  These
  36     changes are reflected in this driver and can be identified
  37     by comparing this driver to the i2c-ali15x3 driver.
  38     For an overview of these chips see http://www.acerlabs.com
  39
  40     The SMB controller is part of the 7101 device, which is an
  41     ACPI-compliant Power Management Unit (PMU).
  42
  43     The whole 7101 device has to be enabled for the SMB to work.
  44     You can't just enable the SMB alone.
  45     The SMB and the ACPI have separate I/O spaces.
  46     We make sure that the SMB is enabled. We leave the ACPI alone.
  47
  48     This driver controls the SMB Host only.
  49
  50     This driver does not use interrupts.
  51 */
  52
  53
  54 /* Note: we assume there can only be one ALI1535, with one SMBus interface */
  55
  56 #include <linux/module.h>
  57 #include <linux/pci.h>
  58 #include <linux/kernel.h>
  59 #include <linux/stddef.h>
  60 #include <linux/delay.h>
  61 #include <linux/ioport.h>
  62 #include <linux/i2c.h>
  63 #include <linux/init.h>
  64 #include <linux/acpi.h>
  65 #include <asm/io.h>
  66
  67
  68 /* ALI1535 SMBus address offsets */
  69 #define SMBHSTSTS       (0 + ali1535_smba)
  70 #define SMBHSTTYP       (1 + ali1535_smba)
  71 #define SMBHSTPORT      (2 + ali1535_smba)
  72 #define SMBHSTCMD       (7 + ali1535_smba)
  73 #define SMBHSTADD       (3 + ali1535_smba)
  74 #define SMBHSTDAT0      (4 + ali1535_smba)
  75 #define SMBHSTDAT1      (5 + ali1535_smba)
  76 #define SMBBLKDAT       (6 + ali1535_smba)
  77
  78 /* PCI Address Constants */
  79 #define SMBCOM          0x004
  80 #define SMBREV          0x008
  81 #define SMBCFG          0x0D1
  82 #define SMBBA           0x0E2
  83 #define SMBHSTCFG       0x0F0
  84 #define SMBCLK          0x0F2
  85
  86 /* Other settings */
  87 #define MAX_TIMEOUT             500     /* times 1/100 sec */
  88 #define ALI1535_SMB_IOSIZE      32
  89
  90 #define ALI1535_SMB_DEFAULTBASE 0x8040
  91
  92 /* ALI1535 address lock bits */
  93 #define ALI1535_LOCK            0x06    /* dwe */
  94
  95 /* ALI1535 command constants */
  96 #define ALI1535_QUICK           0x00
  97 #define ALI1535_BYTE            0x10
  98 #define ALI1535_BYTE_DATA       0x20
  99 #define ALI1535_WORD_DATA       0x30
 100 #define ALI1535_BLOCK_DATA      0x40
 101 #define ALI1535_I2C_READ        0x60
 102
 103 #define ALI1535_DEV10B_EN       0x80    /* Enable 10-bit addressing in  */
 104                                         /*  I2C read                    */
 105 #define ALI1535_T_OUT           0x08    /* Time-out Command (write)     */
 106 #define ALI1535_A_HIGH_BIT9     0x08    /* Bit 9 of 10-bit address in   */
 107                                         /* Alert-Response-Address       */
 108                                         /* (read)                       */
 109 #define ALI1535_KILL            0x04    /* Kill Command (write)         */
 110 #define ALI1535_A_HIGH_BIT8     0x04    /* Bit 8 of 10-bit address in   */
 111                                         /*  Alert-Response-Address      */
 112                                         /*  (read)                      */
 113
 114 #define ALI1535_D_HI_MASK       0x03    /* Mask for isolating bits 9-8  */
 115                                         /*  of 10-bit address in I2C    */
 116                                         /*  Read Command                */
 117
 118 /* ALI1535 status register bits */
 119 #define ALI1535_STS_IDLE        0x04
 120 #define ALI1535_STS_BUSY        0x08    /* host busy */
 121 #define ALI1535_STS_DONE        0x10    /* transaction complete */
 122 #define ALI1535_STS_DEV         0x20    /* device error */
 123 #define ALI1535_STS_BUSERR      0x40    /* bus error    */
 124 #define ALI1535_STS_FAIL        0x80    /* failed bus transaction */
 125 #define ALI1535_STS_ERR         0xE0    /* all the bad error bits */
 126
 127 #define ALI1535_BLOCK_CLR       0x04    /* reset block data index */
 128
 129 /* ALI1535 device address register bits */
 130 #define ALI1535_RD_ADDR         0x01    /* Read/Write Bit in Device     */
 131                                         /*  Address field               */
 132                                         /*  -> Write = 0                */
 133                                         /*  -> Read  = 1                */
 134 #define ALI1535_SMBIO_EN        0x04    /* SMB I/O Space enable         */
 135
 136 static struct pci_driver ali1535_driver;
 137 static unsigned short ali1535_smba;
 138
 139 /* Detect whether a ALI1535 can be found, and initialize it, where necessary.
 140    Note the differences between kernels with the old PCI BIOS interface and
 141    newer kernels with the real PCI interface. In compat.h some things are
 142    defined to make the transition easier. */
 143 static int ali1535_setup(struct pci_dev *dev)
 144 {
 145         int retval = -ENODEV;
 146         unsigned char temp;
 147
 148         /* Check the following things:
 149                 - SMB I/O address is initialized
 150                 - Device is enabled
 151                 - We can use the addresses
 152         */
 153
 154         /* Determine the address of the SMBus area */
 155         pci_read_config_word(dev, SMBBA, &ali1535_smba);
 156         ali1535_smba &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
 157         if (ali1535_smba == 0) {
 158                 dev_warn(&dev->dev,
 159                         "ALI1535_smb region uninitialized - upgrade BIOS?\n");
 160                 goto exit;
 161         }
 162
 163         retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 164                                    ali1535_driver.name);
 165         if (retval)
 166                 goto exit;
 167
 168         if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 169                             ali1535_driver.name)) {
 170                 dev_err(&dev->dev, "ALI1535_smb region 0x%x already in use!\n",
 171                         ali1535_smba);
 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                 goto exit_free;
 180         }
 181
 182         /* Is SMB Host controller enabled? */
 183         pci_read_config_byte(dev, SMBHSTCFG, &temp);
 184         if ((temp & 1) == 0) {
 185                 dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
 186                 goto exit_free;
 187         }
 188
 189         /* set SMB clock to 74KHz as recommended in data sheet */
 190         pci_write_config_byte(dev, SMBCLK, 0x20);
 191
 192         /*
 193           The interrupt routing for SMB is set up in register 0x77 in the
 194           1533 ISA Bridge device, NOT in the 7101 device.
 195           Don't bother with finding the 1533 device and reading the register.
 196         if ((....... & 0x0F) == 1)
 197                 dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
 198         */
 199         pci_read_config_byte(dev, SMBREV, &temp);
 200         dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
 201         dev_dbg(&dev->dev, "ALI1535_smba = 0x%X\n", ali1535_smba);
 202
 203         retval = 0;
 204 exit:
 205         return retval;
 206
 207 exit_free:
 208         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 209         return retval;
 210 }
 211
 212 static int ali1535_transaction(struct i2c_adapter *adap)
 213 {
 214         int temp;
 215         int result = 0;
 216         int timeout = 0;
 217
 218         dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
 219                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 220                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 221                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 222
 223         /* get status */
 224         temp = inb_p(SMBHSTSTS);
 225
 226         /* Make sure the SMBus host is ready to start transmitting */
 227         /* Check the busy bit first */
 228         if (temp & ALI1535_STS_BUSY) {
 229                 /* If the host controller is still busy, it may have timed out
 230                  * in the previous transaction, resulting in a "SMBus Timeout"
 231                  * printk.  I've tried the following to reset a stuck busy bit.
 232                  *   1. Reset the controller with an KILL command. (this
 233                  *      doesn't seem to clear the controller if an external
 234                  *      device is hung)
 235                  *   2. Reset the controller and the other SMBus devices with a
 236                  *      T_OUT command. (this clears the host busy bit if an
 237                  *      external device is hung, but it comes back upon a new
 238                  *      access to a device)
 239                  *   3. Disable and reenable the controller in SMBHSTCFG. Worst
 240                  *      case, nothing seems to work except power reset.
 241                  */
 242
 243                 /* Try resetting entire SMB bus, including other devices - This
 244                  * may not work either - it clears the BUSY bit but then the
 245                  * BUSY bit may come back on when you try and use the chip
 246                  * again.  If that's the case you are stuck.
 247                  */
 248                 dev_info(&adap->dev,
 249                         "Resetting entire SMB Bus to clear busy condition (%02x)\n",
 250                         temp);
 251                 outb_p(ALI1535_T_OUT, SMBHSTTYP);
 252                 temp = inb_p(SMBHSTSTS);
 253         }
 254
 255         /* now check the error bits and the busy bit */
 256         if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 257                 /* do a clear-on-write */
 258                 outb_p(0xFF, SMBHSTSTS);
 259                 if ((temp = inb_p(SMBHSTSTS)) &
 260                     (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 261                         /* This is probably going to be correctable only by a
 262                          * power reset as one of the bits now appears to be
 263                          * stuck */
 264                         /* This may be a bus or device with electrical problems. */
 265                         dev_err(&adap->dev,
 266                                 "SMBus reset failed! (0x%02x) - controller or "
 267                                 "device on bus is probably hung\n", temp);
 268                         return -1;
 269                 }
 270         } else {
 271                 /* check and clear done bit */
 272                 if (temp & ALI1535_STS_DONE) {
 273                         outb_p(temp, SMBHSTSTS);
 274                 }
 275         }
 276
 277         /* start the transaction by writing anything to the start register */
 278         outb_p(0xFF, SMBHSTPORT);
 279
 280         /* We will always wait for a fraction of a second! */
 281         timeout = 0;
 282         do {
 283                 msleep(1);
 284                 temp = inb_p(SMBHSTSTS);
 285         } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
 286                  && (timeout++ < MAX_TIMEOUT));
 287
 288         /* If the SMBus is still busy, we give up */
 289         if (timeout >= MAX_TIMEOUT) {
 290                 result = -1;
 291                 dev_err(&adap->dev, "SMBus Timeout!\n");
 292         }
 293
 294         if (temp & ALI1535_STS_FAIL) {
 295                 result = -1;
 296                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 297         }
 298
 299         /* Unfortunately the ALI SMB controller maps "no response" and "bus
 300          * collision" into a single bit. No reponse is the usual case so don't
 301          * do a printk.  This means that bus collisions go unreported.
 302          */
 303         if (temp & ALI1535_STS_BUSERR) {
 304                 result = -1;
 305                 dev_dbg(&adap->dev,
 306                         "Error: no response or bus collision ADD=%02x\n",
 307                         inb_p(SMBHSTADD));
 308         }
 309
 310         /* haven't ever seen this */
 311         if (temp & ALI1535_STS_DEV) {
 312                 result = -1;
 313                 dev_err(&adap->dev, "Error: device error\n");
 314         }
 315
 316         /* check to see if the "command complete" indication is set */
 317         if (!(temp & ALI1535_STS_DONE)) {
 318                 result = -1;
 319                 dev_err(&adap->dev, "Error: command never completed\n");
 320         }
 321
 322         dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
 323                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 324                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 325                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 326
 327         /* take consequent actions for error conditions */
 328         if (!(temp & ALI1535_STS_DONE)) {
 329                 /* issue "kill" to reset host controller */
 330                 outb_p(ALI1535_KILL,SMBHSTTYP);
 331                 outb_p(0xFF,SMBHSTSTS);
 332         } else if (temp & ALI1535_STS_ERR) {
 333                 /* issue "timeout" to reset all devices on bus */
 334                 outb_p(ALI1535_T_OUT,SMBHSTTYP);
 335                 outb_p(0xFF,SMBHSTSTS);
 336         }
 337
 338         return result;
 339 }
 340
 341 /* Return -1 on error. */
 342 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 343                           unsigned short flags, char read_write, u8 command,
 344                           int size, union i2c_smbus_data *data)
 345 {
 346         int i, len;
 347         int temp;
 348         int timeout;
 349         s32 result = 0;
 350
 351         /* make sure SMBus is idle */
 352         temp = inb_p(SMBHSTSTS);
 353         for (timeout = 0;
 354              (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
 355              timeout++) {
 356                 msleep(1);
 357                 temp = inb_p(SMBHSTSTS);
 358         }
 359         if (timeout >= MAX_TIMEOUT)
 360                 dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 361
 362         /* clear status register (clear-on-write) */
 363         outb_p(0xFF, SMBHSTSTS);
 364
 365         switch (size) {
 366         case I2C_SMBUS_PROC_CALL:
 367                 dev_err(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
 368                 result = -1;
 369                 goto EXIT;
 370         case I2C_SMBUS_QUICK:
 371                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 372                        SMBHSTADD);
 373                 size = ALI1535_QUICK;
 374                 outb_p(size, SMBHSTTYP);        /* output command */
 375                 break;
 376         case I2C_SMBUS_BYTE:
 377                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 378                        SMBHSTADD);
 379                 size = ALI1535_BYTE;
 380                 outb_p(size, SMBHSTTYP);        /* output command */
 381                 if (read_write == I2C_SMBUS_WRITE)
 382                         outb_p(command, SMBHSTCMD);
 383                 break;
 384         case I2C_SMBUS_BYTE_DATA:
 385                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 386                        SMBHSTADD);
 387                 size = ALI1535_BYTE_DATA;
 388                 outb_p(size, SMBHSTTYP);        /* output command */
 389                 outb_p(command, SMBHSTCMD);
 390                 if (read_write == I2C_SMBUS_WRITE)
 391                         outb_p(data->byte, SMBHSTDAT0);
 392                 break;
 393         case I2C_SMBUS_WORD_DATA:
 394                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 395                        SMBHSTADD);
 396                 size = ALI1535_WORD_DATA;
 397                 outb_p(size, SMBHSTTYP);        /* output command */
 398                 outb_p(command, SMBHSTCMD);
 399                 if (read_write == I2C_SMBUS_WRITE) {
 400                         outb_p(data->word & 0xff, SMBHSTDAT0);
 401                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 402                 }
 403                 break;
 404         case I2C_SMBUS_BLOCK_DATA:
 405                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 406                        SMBHSTADD);
 407                 size = ALI1535_BLOCK_DATA;
 408                 outb_p(size, SMBHSTTYP);        /* output command */
 409                 outb_p(command, SMBHSTCMD);
 410                 if (read_write == I2C_SMBUS_WRITE) {
 411                         len = data->block[0];
 412                         if (len < 0) {
 413                                 len = 0;
 414                                 data->block[0] = len;
 415                         }
 416                         if (len > 32) {
 417                                 len = 32;
 418                                 data->block[0] = len;
 419                         }
 420                         outb_p(len, SMBHSTDAT0);
 421                         /* Reset SMBBLKDAT */
 422                         outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 423                         for (i = 1; i <= len; i++)
 424                                 outb_p(data->block[i], SMBBLKDAT);
 425                 }
 426                 break;
 427         }
 428
 429         if (ali1535_transaction(adap)) {
 430                 /* Error in transaction */
 431                 result = -1;
 432                 goto EXIT;
 433         }
 434
 435         if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
 436                 result = 0;
 437                 goto EXIT;
 438         }
 439
 440         switch (size) {
 441         case ALI1535_BYTE:      /* Result put in SMBHSTDAT0 */
 442                 data->byte = inb_p(SMBHSTDAT0);
 443                 break;
 444         case ALI1535_BYTE_DATA:
 445                 data->byte = inb_p(SMBHSTDAT0);
 446                 break;
 447         case ALI1535_WORD_DATA:
 448                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 449                 break;
 450         case ALI1535_BLOCK_DATA:
 451                 len = inb_p(SMBHSTDAT0);
 452                 if (len > 32)
 453                         len = 32;
 454                 data->block[0] = len;
 455                 /* Reset SMBBLKDAT */
 456                 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 457                 for (i = 1; i <= data->block[0]; i++) {
 458                         data->block[i] = inb_p(SMBBLKDAT);
 459                         dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 460                                 len, i, data->block[i]);
 461                 }
 462                 break;
 463         }
 464 EXIT:
 465         return result;
 466 }
 467
 468
 469 static u32 ali1535_func(struct i2c_adapter *adapter)
 470 {
 471         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 472             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 473             I2C_FUNC_SMBUS_BLOCK_DATA;
 474 }
 475
 476 static const struct i2c_algorithm smbus_algorithm = {
 477         .smbus_xfer     = ali1535_access,
 478         .functionality  = ali1535_func,
 479 };
 480
 481 static struct i2c_adapter ali1535_adapter = {
 482         .owner          = THIS_MODULE,
 483         .id             = I2C_HW_SMBUS_ALI1535,
 484         .class          = I2C_CLASS_HWMON,
 485         .algo           = &smbus_algorithm,
 486 };
 487
 488 static struct pci_device_id ali1535_ids[] = {
 489         { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 490         { },
 491 };
 492
 493 MODULE_DEVICE_TABLE (pci, ali1535_ids);
 494
 495 static int __devinit ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
 496 {
 497         if (ali1535_setup(dev)) {
 498                 dev_warn(&dev->dev,
 499                         "ALI1535 not detected, module not inserted.\n");
 500                 return -ENODEV;
 501         }
 502
 503         /* set up the sysfs linkage to our parent device */
 504         ali1535_adapter.dev.parent = &dev->dev;
 505
 506         snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
 507                 "SMBus ALI1535 adapter at %04x", ali1535_smba);
 508         return i2c_add_adapter(&ali1535_adapter);
 509 }
 510
 511 static void __devexit ali1535_remove(struct pci_dev *dev)
 512 {
 513         i2c_del_adapter(&ali1535_adapter);
 514         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 515 }
 516
 517 static struct pci_driver ali1535_driver = {
 518         .name           = "ali1535_smbus",
 519         .id_table       = ali1535_ids,
 520         .probe          = ali1535_probe,
 521         .remove         = __devexit_p(ali1535_remove),
 522 };
 523
 524 static int __init i2c_ali1535_init(void)
 525 {
 526         return pci_register_driver(&ali1535_driver);
 527 }
 528
 529 static void __exit i2c_ali1535_exit(void)
 530 {
 531         pci_unregister_driver(&ali1535_driver);
 532 }
 533
 534 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 535               "Philip Edelbrock <phil@netroedge.com>, "
 536               "Mark D. Studebaker <mdsxyz123@yahoo.com> "
 537               "and Dan Eaton <dan.eaton@rocketlogix.com>");
 538 MODULE_DESCRIPTION("ALI1535 SMBus driver");
 539 MODULE_LICENSE("GPL");
 540
 541 module_init(i2c_ali1535_init);
 542 module_exit(i2c_ali1535_exit);