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 long ali1535_smba;
 136 static unsigned short ali1535_offset;
 137
 138 /* Detect whether a ALI1535 can be found, and initialize it, where necessary.
 139    Note the differences between kernels with the old PCI BIOS interface and
 140    newer kernels with the real PCI interface. In compat.h some things are
 141    defined to make the transition easier. */
 142 static int ali1535_setup(struct pci_dev *dev)
 143 {
 144         int retval;
 145         unsigned char temp;
 146
 147         /* Check the following things:
 148                 - SMB I/O address is initialized
 149                 - Device is enabled
 150                 - We can use the addresses
 151         */
 152
 153         retval = pci_enable_device(dev);
 154         if (retval) {
 155                 dev_err(&dev->dev, "ALI1535_smb can't enable device\n");
 156                 goto exit;
 157         }
 158
 159         /* Determine the address of the SMBus area */
 160         pci_read_config_word(dev, SMBBA, &ali1535_offset);
 161         dev_dbg(&dev->dev, "ALI1535_smb is at offset 0x%04x\n", ali1535_offset);
 162         ali1535_offset &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
 163         if (ali1535_offset == 0) {
 164                 dev_warn(&dev->dev,
 165                         "ALI1535_smb region uninitialized - upgrade BIOS?\n");
 166                 retval = -ENODEV;
 167                 goto exit;
 168         }
 169
 170         if (pci_resource_flags(dev, 0) & IORESOURCE_IO)
 171                 ali1535_smba = pci_resource_start(dev, 0) + ali1535_offset;
 172         else
 173                 ali1535_smba = ali1535_offset;
 174
 175         retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 176                                    ali1535_driver.name);
 177         if (retval)
 178                 goto exit;
 179
 180         if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 181                             ali1535_driver.name)) {
 182                 dev_err(&dev->dev, "ALI1535_smb region 0x%lx already in use!\n",
 183                         ali1535_smba);
 184                 retval = -EBUSY;
 185                 goto exit;
 186         }
 187
 188         /* check if whole device is enabled */
 189         pci_read_config_byte(dev, SMBCFG, &temp);
 190         if ((temp & ALI1535_SMBIO_EN) == 0) {
 191                 dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
 192                 retval = -ENODEV;
 193                 goto exit_free;
 194         }
 195
 196         /* Is SMB Host controller enabled? */
 197         pci_read_config_byte(dev, SMBHSTCFG, &temp);
 198         if ((temp & 1) == 0) {
 199                 dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
 200                 retval = -ENODEV;
 201                 goto exit_free;
 202         }
 203
 204         /* set SMB clock to 74KHz as recommended in data sheet */
 205         pci_write_config_byte(dev, SMBCLK, 0x20);
 206
 207         /*
 208           The interrupt routing for SMB is set up in register 0x77 in the
 209           1533 ISA Bridge device, NOT in the 7101 device.
 210           Don't bother with finding the 1533 device and reading the register.
 211         if ((....... & 0x0F) == 1)
 212                 dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
 213         */
 214         pci_read_config_byte(dev, SMBREV, &temp);
 215         dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
 216         dev_dbg(&dev->dev, "ALI1535_smba = 0x%lx\n", ali1535_smba);
 217
 218         return 0;
 219
 220 exit_free:
 221         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 222 exit:
 223         return retval;
 224 }
 225
 226 static int ali1535_transaction(struct i2c_adapter *adap)
 227 {
 228         int temp;
 229         int result = 0;
 230         int timeout = 0;
 231
 232         dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
 233                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 234                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 235                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 236
 237         /* get status */
 238         temp = inb_p(SMBHSTSTS);
 239
 240         /* Make sure the SMBus host is ready to start transmitting */
 241         /* Check the busy bit first */
 242         if (temp & ALI1535_STS_BUSY) {
 243                 /* If the host controller is still busy, it may have timed out
 244                  * in the previous transaction, resulting in a "SMBus Timeout"
 245                  * printk.  I've tried the following to reset a stuck busy bit.
 246                  *   1. Reset the controller with an KILL command. (this
 247                  *      doesn't seem to clear the controller if an external
 248                  *      device is hung)
 249                  *   2. Reset the controller and the other SMBus devices with a
 250                  *      T_OUT command. (this clears the host busy bit if an
 251                  *      external device is hung, but it comes back upon a new
 252                  *      access to a device)
 253                  *   3. Disable and reenable the controller in SMBHSTCFG. Worst
 254                  *      case, nothing seems to work except power reset.
 255                  */
 256
 257                 /* Try resetting entire SMB bus, including other devices - This
 258                  * may not work either - it clears the BUSY bit but then the
 259                  * BUSY bit may come back on when you try and use the chip
 260                  * again.  If that's the case you are stuck.
 261                  */
 262                 dev_info(&adap->dev,
 263                         "Resetting entire SMB Bus to clear busy condition (%02x)\n",
 264                         temp);
 265                 outb_p(ALI1535_T_OUT, SMBHSTTYP);
 266                 temp = inb_p(SMBHSTSTS);
 267         }
 268
 269         /* now check the error bits and the busy bit */
 270         if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 271                 /* do a clear-on-write */
 272                 outb_p(0xFF, SMBHSTSTS);
 273                 temp = inb_p(SMBHSTSTS);
 274                 if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 275                         /* This is probably going to be correctable only by a
 276                          * power reset as one of the bits now appears to be
 277                          * stuck */
 278                         /* This may be a bus or device with electrical problems. */
 279                         dev_err(&adap->dev,
 280                                 "SMBus reset failed! (0x%02x) - controller or "
 281                                 "device on bus is probably hung\n", temp);
 282                         return -EBUSY;
 283                 }
 284         } else {
 285                 /* check and clear done bit */
 286                 if (temp & ALI1535_STS_DONE)
 287                         outb_p(temp, SMBHSTSTS);
 288         }
 289
 290         /* start the transaction by writing anything to the start register */
 291         outb_p(0xFF, SMBHSTPORT);
 292
 293         /* We will always wait for a fraction of a second! */
 294         timeout = 0;
 295         do {
 296                 usleep_range(1000, 2000);
 297                 temp = inb_p(SMBHSTSTS);
 298         } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
 299                  && (timeout++ < MAX_TIMEOUT));
 300
 301         /* If the SMBus is still busy, we give up */
 302         if (timeout > MAX_TIMEOUT) {
 303                 result = -ETIMEDOUT;
 304                 dev_err(&adap->dev, "SMBus Timeout!\n");
 305         }
 306
 307         if (temp & ALI1535_STS_FAIL) {
 308                 result = -EIO;
 309                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 310         }
 311
 312         /* Unfortunately the ALI SMB controller maps "no response" and "bus
 313          * collision" into a single bit. No response is the usual case so don't
 314          * do a printk.  This means that bus collisions go unreported.
 315          */
 316         if (temp & ALI1535_STS_BUSERR) {
 317                 result = -ENXIO;
 318                 dev_dbg(&adap->dev,
 319                         "Error: no response or bus collision ADD=%02x\n",
 320                         inb_p(SMBHSTADD));
 321         }
 322
 323         /* haven't ever seen this */
 324         if (temp & ALI1535_STS_DEV) {
 325                 result = -EIO;
 326                 dev_err(&adap->dev, "Error: device error\n");
 327         }
 328
 329         /* check to see if the "command complete" indication is set */
 330         if (!(temp & ALI1535_STS_DONE)) {
 331                 result = -ETIMEDOUT;
 332                 dev_err(&adap->dev, "Error: command never completed\n");
 333         }
 334
 335         dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
 336                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 337                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 338                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 339
 340         /* take consequent actions for error conditions */
 341         if (!(temp & ALI1535_STS_DONE)) {
 342                 /* issue "kill" to reset host controller */
 343                 outb_p(ALI1535_KILL, SMBHSTTYP);
 344                 outb_p(0xFF, SMBHSTSTS);
 345         } else if (temp & ALI1535_STS_ERR) {
 346                 /* issue "timeout" to reset all devices on bus */
 347                 outb_p(ALI1535_T_OUT, SMBHSTTYP);
 348                 outb_p(0xFF, SMBHSTSTS);
 349         }
 350
 351         return result;
 352 }
 353
 354 /* Return negative errno on error. */
 355 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 356                           unsigned short flags, char read_write, u8 command,
 357                           int size, union i2c_smbus_data *data)
 358 {
 359         int i, len;
 360         int temp;
 361         int timeout;
 362         s32 result = 0;
 363
 364         /* make sure SMBus is idle */
 365         temp = inb_p(SMBHSTSTS);
 366         for (timeout = 0;
 367              (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
 368              timeout++) {
 369                 usleep_range(1000, 2000);
 370                 temp = inb_p(SMBHSTSTS);
 371         }
 372         if (timeout >= MAX_TIMEOUT)
 373                 dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 374
 375         /* clear status register (clear-on-write) */
 376         outb_p(0xFF, SMBHSTSTS);
 377
 378         switch (size) {
 379         case I2C_SMBUS_QUICK:
 380                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 381                        SMBHSTADD);
 382                 size = ALI1535_QUICK;
 383                 outb_p(size, SMBHSTTYP);        /* output command */
 384                 break;
 385         case I2C_SMBUS_BYTE:
 386                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 387                        SMBHSTADD);
 388                 size = ALI1535_BYTE;
 389                 outb_p(size, SMBHSTTYP);        /* output command */
 390                 if (read_write == I2C_SMBUS_WRITE)
 391                         outb_p(command, SMBHSTCMD);
 392                 break;
 393         case I2C_SMBUS_BYTE_DATA:
 394                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 395                        SMBHSTADD);
 396                 size = ALI1535_BYTE_DATA;
 397                 outb_p(size, SMBHSTTYP);        /* output command */
 398                 outb_p(command, SMBHSTCMD);
 399                 if (read_write == I2C_SMBUS_WRITE)
 400                         outb_p(data->byte, SMBHSTDAT0);
 401                 break;
 402         case I2C_SMBUS_WORD_DATA:
 403                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 404                        SMBHSTADD);
 405                 size = ALI1535_WORD_DATA;
 406                 outb_p(size, SMBHSTTYP);        /* output command */
 407                 outb_p(command, SMBHSTCMD);
 408                 if (read_write == I2C_SMBUS_WRITE) {
 409                         outb_p(data->word & 0xff, SMBHSTDAT0);
 410                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 411                 }
 412                 break;
 413         case I2C_SMBUS_BLOCK_DATA:
 414                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 415                        SMBHSTADD);
 416                 size = ALI1535_BLOCK_DATA;
 417                 outb_p(size, SMBHSTTYP);        /* output command */
 418                 outb_p(command, SMBHSTCMD);
 419                 if (read_write == I2C_SMBUS_WRITE) {
 420                         len = data->block[0];
 421                         if (len < 0) {
 422                                 len = 0;
 423                                 data->block[0] = len;
 424                         }
 425                         if (len > 32) {
 426                                 len = 32;
 427                                 data->block[0] = len;
 428                         }
 429                         outb_p(len, SMBHSTDAT0);
 430                         /* Reset SMBBLKDAT */
 431                         outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 432                         for (i = 1; i <= len; i++)
 433                                 outb_p(data->block[i], SMBBLKDAT);
 434                 }
 435                 break;
 436         default:
 437                 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 438                 result = -EOPNOTSUPP;
 439                 goto EXIT;
 440         }
 441
 442         result = ali1535_transaction(adap);
 443         if (result)
 444                 goto EXIT;
 445
 446         if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
 447                 result = 0;
 448                 goto EXIT;
 449         }
 450
 451         switch (size) {
 452         case ALI1535_BYTE:      /* Result put in SMBHSTDAT0 */
 453                 data->byte = inb_p(SMBHSTDAT0);
 454                 break;
 455         case ALI1535_BYTE_DATA:
 456                 data->byte = inb_p(SMBHSTDAT0);
 457                 break;
 458         case ALI1535_WORD_DATA:
 459                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 460                 break;
 461         case ALI1535_BLOCK_DATA:
 462                 len = inb_p(SMBHSTDAT0);
 463                 if (len > 32)
 464                         len = 32;
 465                 data->block[0] = len;
 466                 /* Reset SMBBLKDAT */
 467                 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 468                 for (i = 1; i <= data->block[0]; i++) {
 469                         data->block[i] = inb_p(SMBBLKDAT);
 470                         dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 471                                 len, i, data->block[i]);
 472                 }
 473                 break;
 474         }
 475 EXIT:
 476         return result;
 477 }
 478
 479
 480 static u32 ali1535_func(struct i2c_adapter *adapter)
 481 {
 482         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 483             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 484             I2C_FUNC_SMBUS_BLOCK_DATA;
 485 }
 486
 487 static const struct i2c_algorithm smbus_algorithm = {
 488         .smbus_xfer     = ali1535_access,
 489         .functionality  = ali1535_func,
 490 };
 491
 492 static struct i2c_adapter ali1535_adapter = {
 493         .owner          = THIS_MODULE,
 494         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 495         .algo           = &smbus_algorithm,
 496 };
 497
 498 static DEFINE_PCI_DEVICE_TABLE(ali1535_ids) = {
 499         { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 500         { },
 501 };
 502
 503 MODULE_DEVICE_TABLE(pci, ali1535_ids);
 504
 505 static int ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
 506 {
 507         if (ali1535_setup(dev)) {
 508                 dev_warn(&dev->dev,
 509                         "ALI1535 not detected, module not inserted.\n");
 510                 return -ENODEV;
 511         }
 512
 513         /* set up the sysfs linkage to our parent device */
 514         ali1535_adapter.dev.parent = &dev->dev;
 515
 516         snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
 517                 "SMBus ALI1535 adapter at %04x", ali1535_offset);
 518         return i2c_add_adapter(&ali1535_adapter);
 519 }
 520
 521 static void ali1535_remove(struct pci_dev *dev)
 522 {
 523         i2c_del_adapter(&ali1535_adapter);
 524         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 525 }
 526
 527 static struct pci_driver ali1535_driver = {
 528         .name           = "ali1535_smbus",
 529         .id_table       = ali1535_ids,
 530         .probe          = ali1535_probe,
 531         .remove         = ali1535_remove,
 532 };
 533
 534 module_pci_driver(ali1535_driver);
 535
 536 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 537               "Philip Edelbrock <phil@netroedge.com>, "
 538               "Mark D. Studebaker <mdsxyz123@yahoo.com> "
 539               "and Dan Eaton <dan.eaton@rocketlogix.com>");
 540 MODULE_DESCRIPTION("ALI1535 SMBus driver");
 541 MODULE_LICENSE("GPL");