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/acpi.h>
  62 #include <linux/io.h>
  63
  64
  65 /* ALI1535 SMBus address offsets */
  66 #define SMBHSTSTS       (0 + ali1535_smba)
  67 #define SMBHSTTYP       (1 + ali1535_smba)
  68 #define SMBHSTPORT      (2 + ali1535_smba)
  69 #define SMBHSTCMD       (7 + ali1535_smba)
  70 #define SMBHSTADD       (3 + ali1535_smba)
  71 #define SMBHSTDAT0      (4 + ali1535_smba)
  72 #define SMBHSTDAT1      (5 + ali1535_smba)
  73 #define SMBBLKDAT       (6 + ali1535_smba)
  74
  75 /* PCI Address Constants */
  76 #define SMBCOM          0x004
  77 #define SMBREV          0x008
  78 #define SMBCFG          0x0D1
  79 #define SMBBA           0x0E2
  80 #define SMBHSTCFG       0x0F0
  81 #define SMBCLK          0x0F2
  82
  83 /* Other settings */
  84 #define MAX_TIMEOUT             500     /* times 1/100 sec */
  85 #define ALI1535_SMB_IOSIZE      32
  86
  87 #define ALI1535_SMB_DEFAULTBASE 0x8040
  88
  89 /* ALI1535 address lock bits */
  90 #define ALI1535_LOCK            0x06    /* dwe */
  91
  92 /* ALI1535 command constants */
  93 #define ALI1535_QUICK           0x00
  94 #define ALI1535_BYTE            0x10
  95 #define ALI1535_BYTE_DATA       0x20
  96 #define ALI1535_WORD_DATA       0x30
  97 #define ALI1535_BLOCK_DATA      0x40
  98 #define ALI1535_I2C_READ        0x60
  99
 100 #define ALI1535_DEV10B_EN       0x80    /* Enable 10-bit addressing in  */
 101                                         /*  I2C read                    */
 102 #define ALI1535_T_OUT           0x08    /* Time-out Command (write)     */
 103 #define ALI1535_A_HIGH_BIT9     0x08    /* Bit 9 of 10-bit address in   */
 104                                         /* Alert-Response-Address       */
 105                                         /* (read)                       */
 106 #define ALI1535_KILL            0x04    /* Kill Command (write)         */
 107 #define ALI1535_A_HIGH_BIT8     0x04    /* Bit 8 of 10-bit address in   */
 108                                         /*  Alert-Response-Address      */
 109                                         /*  (read)                      */
 110
 111 #define ALI1535_D_HI_MASK       0x03    /* Mask for isolating bits 9-8  */
 112                                         /*  of 10-bit address in I2C    */
 113                                         /*  Read Command                */
 114
 115 /* ALI1535 status register bits */
 116 #define ALI1535_STS_IDLE        0x04
 117 #define ALI1535_STS_BUSY        0x08    /* host busy */
 118 #define ALI1535_STS_DONE        0x10    /* transaction complete */
 119 #define ALI1535_STS_DEV         0x20    /* device error */
 120 #define ALI1535_STS_BUSERR      0x40    /* bus error    */
 121 #define ALI1535_STS_FAIL        0x80    /* failed bus transaction */
 122 #define ALI1535_STS_ERR         0xE0    /* all the bad error bits */
 123
 124 #define ALI1535_BLOCK_CLR       0x04    /* reset block data index */
 125
 126 /* ALI1535 device address register bits */
 127 #define ALI1535_RD_ADDR         0x01    /* Read/Write Bit in Device     */
 128                                         /*  Address field               */
 129                                         /*  -> Write = 0                */
 130                                         /*  -> Read  = 1                */
 131 #define ALI1535_SMBIO_EN        0x04    /* SMB I/O Space enable         */
 132
 133 static struct pci_driver ali1535_driver;
 134 static unsigned long ali1535_smba;
 135 static unsigned short ali1535_offset;
 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 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         retval = pci_enable_device(dev);
 153         if (retval) {
 154                 dev_err(&dev->dev, "ALI1535_smb can't enable device\n");
 155                 goto exit;
 156         }
 157
 158         /* Determine the address of the SMBus area */
 159         pci_read_config_word(dev, SMBBA, &ali1535_offset);
 160         dev_dbg(&dev->dev, "ALI1535_smb is at offset 0x%04x\n", ali1535_offset);
 161         ali1535_offset &= (0xffff & ~(ALI1535_SMB_IOSIZE - 1));
 162         if (ali1535_offset == 0) {
 163                 dev_warn(&dev->dev,
 164                         "ALI1535_smb region uninitialized - upgrade BIOS?\n");
 165                 retval = -ENODEV;
 166                 goto exit;
 167         }
 168
 169         if (pci_resource_flags(dev, 0) & IORESOURCE_IO)
 170                 ali1535_smba = pci_resource_start(dev, 0) + ali1535_offset;
 171         else
 172                 ali1535_smba = ali1535_offset;
 173
 174         retval = acpi_check_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 175                                    ali1535_driver.name);
 176         if (retval)
 177                 goto exit;
 178
 179         if (!request_region(ali1535_smba, ALI1535_SMB_IOSIZE,
 180                             ali1535_driver.name)) {
 181                 dev_err(&dev->dev, "ALI1535_smb region 0x%lx already in use!\n",
 182                         ali1535_smba);
 183                 retval = -EBUSY;
 184                 goto exit;
 185         }
 186
 187         /* check if whole device is enabled */
 188         pci_read_config_byte(dev, SMBCFG, &temp);
 189         if ((temp & ALI1535_SMBIO_EN) == 0) {
 190                 dev_err(&dev->dev, "SMB device not enabled - upgrade BIOS?\n");
 191                 retval = -ENODEV;
 192                 goto exit_free;
 193         }
 194
 195         /* Is SMB Host controller enabled? */
 196         pci_read_config_byte(dev, SMBHSTCFG, &temp);
 197         if ((temp & 1) == 0) {
 198                 dev_err(&dev->dev, "SMBus controller not enabled - upgrade BIOS?\n");
 199                 retval = -ENODEV;
 200                 goto exit_free;
 201         }
 202
 203         /* set SMB clock to 74KHz as recommended in data sheet */
 204         pci_write_config_byte(dev, SMBCLK, 0x20);
 205
 206         /*
 207           The interrupt routing for SMB is set up in register 0x77 in the
 208           1533 ISA Bridge device, NOT in the 7101 device.
 209           Don't bother with finding the 1533 device and reading the register.
 210         if ((....... & 0x0F) == 1)
 211                 dev_dbg(&dev->dev, "ALI1535 using Interrupt 9 for SMBus.\n");
 212         */
 213         pci_read_config_byte(dev, SMBREV, &temp);
 214         dev_dbg(&dev->dev, "SMBREV = 0x%X\n", temp);
 215         dev_dbg(&dev->dev, "ALI1535_smba = 0x%lx\n", ali1535_smba);
 216
 217         return 0;
 218
 219 exit_free:
 220         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 221 exit:
 222         return retval;
 223 }
 224
 225 static int ali1535_transaction(struct i2c_adapter *adap)
 226 {
 227         int temp;
 228         int result = 0;
 229         int timeout = 0;
 230
 231         dev_dbg(&adap->dev, "Transaction (pre): STS=%02x, TYP=%02x, "
 232                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 233                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 234                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 235
 236         /* get status */
 237         temp = inb_p(SMBHSTSTS);
 238
 239         /* Make sure the SMBus host is ready to start transmitting */
 240         /* Check the busy bit first */
 241         if (temp & ALI1535_STS_BUSY) {
 242                 /* If the host controller is still busy, it may have timed out
 243                  * in the previous transaction, resulting in a "SMBus Timeout"
 244                  * printk.  I've tried the following to reset a stuck busy bit.
 245                  *   1. Reset the controller with an KILL command. (this
 246                  *      doesn't seem to clear the controller if an external
 247                  *      device is hung)
 248                  *   2. Reset the controller and the other SMBus devices with a
 249                  *      T_OUT command. (this clears the host busy bit if an
 250                  *      external device is hung, but it comes back upon a new
 251                  *      access to a device)
 252                  *   3. Disable and reenable the controller in SMBHSTCFG. Worst
 253                  *      case, nothing seems to work except power reset.
 254                  */
 255
 256                 /* Try resetting entire SMB bus, including other devices - This
 257                  * may not work either - it clears the BUSY bit but then the
 258                  * BUSY bit may come back on when you try and use the chip
 259                  * again.  If that's the case you are stuck.
 260                  */
 261                 dev_info(&adap->dev,
 262                         "Resetting entire SMB Bus to clear busy condition (%02x)\n",
 263                         temp);
 264                 outb_p(ALI1535_T_OUT, SMBHSTTYP);
 265                 temp = inb_p(SMBHSTSTS);
 266         }
 267
 268         /* now check the error bits and the busy bit */
 269         if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 270                 /* do a clear-on-write */
 271                 outb_p(0xFF, SMBHSTSTS);
 272                 temp = inb_p(SMBHSTSTS);
 273                 if (temp & (ALI1535_STS_ERR | ALI1535_STS_BUSY)) {
 274                         /* This is probably going to be correctable only by a
 275                          * power reset as one of the bits now appears to be
 276                          * stuck */
 277                         /* This may be a bus or device with electrical problems. */
 278                         dev_err(&adap->dev,
 279                                 "SMBus reset failed! (0x%02x) - controller or "
 280                                 "device on bus is probably hung\n", temp);
 281                         return -EBUSY;
 282                 }
 283         } else {
 284                 /* check and clear done bit */
 285                 if (temp & ALI1535_STS_DONE)
 286                         outb_p(temp, SMBHSTSTS);
 287         }
 288
 289         /* start the transaction by writing anything to the start register */
 290         outb_p(0xFF, SMBHSTPORT);
 291
 292         /* We will always wait for a fraction of a second! */
 293         timeout = 0;
 294         do {
 295                 usleep_range(1000, 2000);
 296                 temp = inb_p(SMBHSTSTS);
 297         } while (((temp & ALI1535_STS_BUSY) && !(temp & ALI1535_STS_IDLE))
 298                  && (timeout++ < MAX_TIMEOUT));
 299
 300         /* If the SMBus is still busy, we give up */
 301         if (timeout > MAX_TIMEOUT) {
 302                 result = -ETIMEDOUT;
 303                 dev_err(&adap->dev, "SMBus Timeout!\n");
 304         }
 305
 306         if (temp & ALI1535_STS_FAIL) {
 307                 result = -EIO;
 308                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 309         }
 310
 311         /* Unfortunately the ALI SMB controller maps "no response" and "bus
 312          * collision" into a single bit. No response is the usual case so don't
 313          * do a printk.  This means that bus collisions go unreported.
 314          */
 315         if (temp & ALI1535_STS_BUSERR) {
 316                 result = -ENXIO;
 317                 dev_dbg(&adap->dev,
 318                         "Error: no response or bus collision ADD=%02x\n",
 319                         inb_p(SMBHSTADD));
 320         }
 321
 322         /* haven't ever seen this */
 323         if (temp & ALI1535_STS_DEV) {
 324                 result = -EIO;
 325                 dev_err(&adap->dev, "Error: device error\n");
 326         }
 327
 328         /* check to see if the "command complete" indication is set */
 329         if (!(temp & ALI1535_STS_DONE)) {
 330                 result = -ETIMEDOUT;
 331                 dev_err(&adap->dev, "Error: command never completed\n");
 332         }
 333
 334         dev_dbg(&adap->dev, "Transaction (post): STS=%02x, TYP=%02x, "
 335                 "CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
 336                 inb_p(SMBHSTSTS), inb_p(SMBHSTTYP), inb_p(SMBHSTCMD),
 337                 inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1));
 338
 339         /* take consequent actions for error conditions */
 340         if (!(temp & ALI1535_STS_DONE)) {
 341                 /* issue "kill" to reset host controller */
 342                 outb_p(ALI1535_KILL, SMBHSTTYP);
 343                 outb_p(0xFF, SMBHSTSTS);
 344         } else if (temp & ALI1535_STS_ERR) {
 345                 /* issue "timeout" to reset all devices on bus */
 346                 outb_p(ALI1535_T_OUT, SMBHSTTYP);
 347                 outb_p(0xFF, SMBHSTSTS);
 348         }
 349
 350         return result;
 351 }
 352
 353 /* Return negative errno on error. */
 354 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 355                           unsigned short flags, char read_write, u8 command,
 356                           int size, union i2c_smbus_data *data)
 357 {
 358         int i, len;
 359         int temp;
 360         int timeout;
 361         s32 result = 0;
 362
 363         /* make sure SMBus is idle */
 364         temp = inb_p(SMBHSTSTS);
 365         for (timeout = 0;
 366              (timeout < MAX_TIMEOUT) && !(temp & ALI1535_STS_IDLE);
 367              timeout++) {
 368                 usleep_range(1000, 2000);
 369                 temp = inb_p(SMBHSTSTS);
 370         }
 371         if (timeout >= MAX_TIMEOUT)
 372                 dev_warn(&adap->dev, "Idle wait Timeout! STS=0x%02x\n", temp);
 373
 374         /* clear status register (clear-on-write) */
 375         outb_p(0xFF, SMBHSTSTS);
 376
 377         switch (size) {
 378         case I2C_SMBUS_QUICK:
 379                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 380                        SMBHSTADD);
 381                 size = ALI1535_QUICK;
 382                 outb_p(size, SMBHSTTYP);        /* output command */
 383                 break;
 384         case I2C_SMBUS_BYTE:
 385                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 386                        SMBHSTADD);
 387                 size = ALI1535_BYTE;
 388                 outb_p(size, SMBHSTTYP);        /* output command */
 389                 if (read_write == I2C_SMBUS_WRITE)
 390                         outb_p(command, SMBHSTCMD);
 391                 break;
 392         case I2C_SMBUS_BYTE_DATA:
 393                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 394                        SMBHSTADD);
 395                 size = ALI1535_BYTE_DATA;
 396                 outb_p(size, SMBHSTTYP);        /* output command */
 397                 outb_p(command, SMBHSTCMD);
 398                 if (read_write == I2C_SMBUS_WRITE)
 399                         outb_p(data->byte, SMBHSTDAT0);
 400                 break;
 401         case I2C_SMBUS_WORD_DATA:
 402                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 403                        SMBHSTADD);
 404                 size = ALI1535_WORD_DATA;
 405                 outb_p(size, SMBHSTTYP);        /* output command */
 406                 outb_p(command, SMBHSTCMD);
 407                 if (read_write == I2C_SMBUS_WRITE) {
 408                         outb_p(data->word & 0xff, SMBHSTDAT0);
 409                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 410                 }
 411                 break;
 412         case I2C_SMBUS_BLOCK_DATA:
 413                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 414                        SMBHSTADD);
 415                 size = ALI1535_BLOCK_DATA;
 416                 outb_p(size, SMBHSTTYP);        /* output command */
 417                 outb_p(command, SMBHSTCMD);
 418                 if (read_write == I2C_SMBUS_WRITE) {
 419                         len = data->block[0];
 420                         if (len < 0) {
 421                                 len = 0;
 422                                 data->block[0] = len;
 423                         }
 424                         if (len > 32) {
 425                                 len = 32;
 426                                 data->block[0] = len;
 427                         }
 428                         outb_p(len, SMBHSTDAT0);
 429                         /* Reset SMBBLKDAT */
 430                         outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 431                         for (i = 1; i <= len; i++)
 432                                 outb_p(data->block[i], SMBBLKDAT);
 433                 }
 434                 break;
 435         default:
 436                 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
 437                 result = -EOPNOTSUPP;
 438                 goto EXIT;
 439         }
 440
 441         result = ali1535_transaction(adap);
 442         if (result)
 443                 goto EXIT;
 444
 445         if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
 446                 result = 0;
 447                 goto EXIT;
 448         }
 449
 450         switch (size) {
 451         case ALI1535_BYTE:      /* Result put in SMBHSTDAT0 */
 452                 data->byte = inb_p(SMBHSTDAT0);
 453                 break;
 454         case ALI1535_BYTE_DATA:
 455                 data->byte = inb_p(SMBHSTDAT0);
 456                 break;
 457         case ALI1535_WORD_DATA:
 458                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 459                 break;
 460         case ALI1535_BLOCK_DATA:
 461                 len = inb_p(SMBHSTDAT0);
 462                 if (len > 32)
 463                         len = 32;
 464                 data->block[0] = len;
 465                 /* Reset SMBBLKDAT */
 466                 outb_p(inb_p(SMBHSTTYP) | ALI1535_BLOCK_CLR, SMBHSTTYP);
 467                 for (i = 1; i <= data->block[0]; i++) {
 468                         data->block[i] = inb_p(SMBBLKDAT);
 469                         dev_dbg(&adap->dev, "Blk: len=%d, i=%d, data=%02x\n",
 470                                 len, i, data->block[i]);
 471                 }
 472                 break;
 473         }
 474 EXIT:
 475         return result;
 476 }
 477
 478
 479 static u32 ali1535_func(struct i2c_adapter *adapter)
 480 {
 481         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 482             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 483             I2C_FUNC_SMBUS_BLOCK_DATA;
 484 }
 485
 486 static const struct i2c_algorithm smbus_algorithm = {
 487         .smbus_xfer     = ali1535_access,
 488         .functionality  = ali1535_func,
 489 };
 490
 491 static struct i2c_adapter ali1535_adapter = {
 492         .owner          = THIS_MODULE,
 493         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 494         .algo           = &smbus_algorithm,
 495 };
 496
 497 static const struct pci_device_id ali1535_ids[] = {
 498         { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
 499         { },
 500 };
 501
 502 MODULE_DEVICE_TABLE(pci, ali1535_ids);
 503
 504 static int ali1535_probe(struct pci_dev *dev, const struct pci_device_id *id)
 505 {
 506         if (ali1535_setup(dev)) {
 507                 dev_warn(&dev->dev,
 508                         "ALI1535 not detected, module not inserted.\n");
 509                 return -ENODEV;
 510         }
 511
 512         /* set up the sysfs linkage to our parent device */
 513         ali1535_adapter.dev.parent = &dev->dev;
 514
 515         snprintf(ali1535_adapter.name, sizeof(ali1535_adapter.name),
 516                 "SMBus ALI1535 adapter at %04x", ali1535_offset);
 517         return i2c_add_adapter(&ali1535_adapter);
 518 }
 519
 520 static void ali1535_remove(struct pci_dev *dev)
 521 {
 522         i2c_del_adapter(&ali1535_adapter);
 523         release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
 524 }
 525
 526 static struct pci_driver ali1535_driver = {
 527         .name           = "ali1535_smbus",
 528         .id_table       = ali1535_ids,
 529         .probe          = ali1535_probe,
 530         .remove         = ali1535_remove,
 531 };
 532
 533 module_pci_driver(ali1535_driver);
 534
 535 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "
 536               "Philip Edelbrock <phil@netroedge.com>, "
 537               "Mark D. Studebaker <mdsxyz123@yahoo.com> "
 538               "and Dan Eaton <dan.eaton@rocketlogix.com>");
 539 MODULE_DESCRIPTION("ALI1535 SMBus driver");
 540 MODULE_LICENSE("GPL");