drivers/i2c/busses/i2c-viapro.c

   1 /*
   2     Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
   3     Philip Edelbrock <phil@netroedge.com>, Kyösti Mälkki <kmalkki@cc.hut.fi>,
   4     Mark D. Studebaker <mdsxyz123@yahoo.com>
   5     Copyright (C) 2005 - 2008  Jean Delvare <khali@linux-fr.org>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 /*
  23    Supports the following VIA south bridges:
  24
  25    Chip name          PCI ID  REV     I2C block
  26    VT82C596A          0x3050             no
  27    VT82C596B          0x3051             no
  28    VT82C686A          0x3057  0x30       no
  29    VT82C686B          0x3057  0x40       yes
  30    VT8231             0x8235             no?
  31    VT8233             0x3074             yes
  32    VT8233A            0x3147             yes?
  33    VT8235             0x3177             yes
  34    VT8237R            0x3227             yes
  35    VT8237A            0x3337             yes
  36    VT8237S            0x3372             yes
  37    VT8251             0x3287             yes
  38    CX700              0x8324             yes
  39    VX800/VX820        0x8353             yes
  40    VX855/VX875        0x8409             yes
  41
  42    Note: we assume there can only be one device, with one SMBus interface.
  43 */
  44
  45 #include <linux/module.h>
  46 #include <linux/delay.h>
  47 #include <linux/pci.h>
  48 #include <linux/kernel.h>
  49 #include <linux/stddef.h>
  50 #include <linux/ioport.h>
  51 #include <linux/i2c.h>
  52 #include <linux/init.h>
  53 #include <linux/acpi.h>
  54 #include <asm/io.h>
  55
  56 static struct pci_dev *vt596_pdev;
  57
  58 #define SMBBA1          0x90
  59 #define SMBBA2          0x80
  60 #define SMBBA3          0xD0
  61
  62 /* SMBus address offsets */
  63 static unsigned short vt596_smba;
  64 #define SMBHSTSTS       (vt596_smba + 0)
  65 #define SMBHSTCNT       (vt596_smba + 2)
  66 #define SMBHSTCMD       (vt596_smba + 3)
  67 #define SMBHSTADD       (vt596_smba + 4)
  68 #define SMBHSTDAT0      (vt596_smba + 5)
  69 #define SMBHSTDAT1      (vt596_smba + 6)
  70 #define SMBBLKDAT       (vt596_smba + 7)
  71
  72 /* PCI Address Constants */
  73
  74 /* SMBus data in configuration space can be found in two places,
  75    We try to select the better one */
  76
  77 static unsigned short SMBHSTCFG = 0xD2;
  78
  79 /* Other settings */
  80 #define MAX_TIMEOUT     500
  81
  82 /* VT82C596 constants */
  83 #define VT596_QUICK             0x00
  84 #define VT596_BYTE              0x04
  85 #define VT596_BYTE_DATA         0x08
  86 #define VT596_WORD_DATA         0x0C
  87 #define VT596_PROC_CALL         0x10
  88 #define VT596_BLOCK_DATA        0x14
  89 #define VT596_I2C_BLOCK_DATA    0x34
  90
  91
  92 /* If force is set to anything different from 0, we forcibly enable the
  93    VT596. DANGEROUS! */
  94 static int force;
  95 module_param(force, bool, 0);
  96 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
  97
  98 /* If force_addr is set to anything different from 0, we forcibly enable
  99    the VT596 at the given address. VERY DANGEROUS! */
 100 static u16 force_addr;
 101 module_param(force_addr, ushort, 0);
 102 MODULE_PARM_DESC(force_addr,
 103                  "Forcibly enable the SMBus at the given address. "
 104                  "EXTREMELY DANGEROUS!");
 105
 106
 107 static struct pci_driver vt596_driver;
 108 static struct i2c_adapter vt596_adapter;
 109
 110 #define FEATURE_I2CBLOCK        (1<<0)
 111 static unsigned int vt596_features;
 112
 113 #ifdef DEBUG
 114 static void vt596_dump_regs(const char *msg, u8 size)
 115 {
 116         dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
 117                 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
 118                 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
 119                 inb_p(SMBHSTDAT1));
 120
 121         if (size == VT596_BLOCK_DATA
 122          || size == VT596_I2C_BLOCK_DATA) {
 123                 int i;
 124
 125                 dev_dbg(&vt596_adapter.dev, "BLK=");
 126                 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
 127                         printk("%02x,", inb_p(SMBBLKDAT));
 128                 printk("\n");
 129                 dev_dbg(&vt596_adapter.dev, "    ");
 130                 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
 131                         printk("%02x,", inb_p(SMBBLKDAT));
 132                 printk("%02x\n", inb_p(SMBBLKDAT));
 133         }
 134 }
 135 #else
 136 static inline void vt596_dump_regs(const char *msg, u8 size) { }
 137 #endif
 138
 139 /* Return -1 on error, 0 on success */
 140 static int vt596_transaction(u8 size)
 141 {
 142         int temp;
 143         int result = 0;
 144         int timeout = 0;
 145
 146         vt596_dump_regs("Transaction (pre)", size);
 147
 148         /* Make sure the SMBus host is ready to start transmitting */
 149         if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 150                 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
 151                         "Resetting...\n", temp);
 152
 153                 outb_p(temp, SMBHSTSTS);
 154                 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 155                         dev_err(&vt596_adapter.dev, "SMBus reset failed! "
 156                                 "(0x%02x)\n", temp);
 157                         return -EBUSY;
 158                 }
 159         }
 160
 161         /* Start the transaction by setting bit 6 */
 162         outb_p(0x40 | size, SMBHSTCNT);
 163
 164         /* We will always wait for a fraction of a second */
 165         do {
 166                 msleep(1);
 167                 temp = inb_p(SMBHSTSTS);
 168         } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
 169
 170         /* If the SMBus is still busy, we give up */
 171         if (timeout >= MAX_TIMEOUT) {
 172                 result = -ETIMEDOUT;
 173                 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
 174         }
 175
 176         if (temp & 0x10) {
 177                 result = -EIO;
 178                 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
 179                         size);
 180         }
 181
 182         if (temp & 0x08) {
 183                 result = -EIO;
 184                 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
 185         }
 186
 187         if (temp & 0x04) {
 188                 int read = inb_p(SMBHSTADD) & 0x01;
 189                 result = -ENXIO;
 190                 /* The quick and receive byte commands are used to probe
 191                    for chips, so errors are expected, and we don't want
 192                    to frighten the user. */
 193                 if (!((size == VT596_QUICK && !read) ||
 194                       (size == VT596_BYTE && read)))
 195                         dev_err(&vt596_adapter.dev, "Transaction error!\n");
 196         }
 197
 198         /* Resetting status register */
 199         if (temp & 0x1F)
 200                 outb_p(temp, SMBHSTSTS);
 201
 202         vt596_dump_regs("Transaction (post)", size);
 203
 204         return result;
 205 }
 206
 207 /* Return negative errno on error, 0 on success */
 208 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
 209                 unsigned short flags, char read_write, u8 command,
 210                 int size, union i2c_smbus_data *data)
 211 {
 212         int i;
 213         int status;
 214
 215         switch (size) {
 216         case I2C_SMBUS_QUICK:
 217                 size = VT596_QUICK;
 218                 break;
 219         case I2C_SMBUS_BYTE:
 220                 if (read_write == I2C_SMBUS_WRITE)
 221                         outb_p(command, SMBHSTCMD);
 222                 size = VT596_BYTE;
 223                 break;
 224         case I2C_SMBUS_BYTE_DATA:
 225                 outb_p(command, SMBHSTCMD);
 226                 if (read_write == I2C_SMBUS_WRITE)
 227                         outb_p(data->byte, SMBHSTDAT0);
 228                 size = VT596_BYTE_DATA;
 229                 break;
 230         case I2C_SMBUS_WORD_DATA:
 231                 outb_p(command, SMBHSTCMD);
 232                 if (read_write == I2C_SMBUS_WRITE) {
 233                         outb_p(data->word & 0xff, SMBHSTDAT0);
 234                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 235                 }
 236                 size = VT596_WORD_DATA;
 237                 break;
 238         case I2C_SMBUS_PROC_CALL:
 239                 outb_p(command, SMBHSTCMD);
 240                 outb_p(data->word & 0xff, SMBHSTDAT0);
 241                 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 242                 size = VT596_PROC_CALL;
 243                 break;
 244         case I2C_SMBUS_I2C_BLOCK_DATA:
 245                 if (!(vt596_features & FEATURE_I2CBLOCK))
 246                         goto exit_unsupported;
 247                 if (read_write == I2C_SMBUS_READ)
 248                         outb_p(data->block[0], SMBHSTDAT0);
 249                 /* Fall through */
 250         case I2C_SMBUS_BLOCK_DATA:
 251                 outb_p(command, SMBHSTCMD);
 252                 if (read_write == I2C_SMBUS_WRITE) {
 253                         u8 len = data->block[0];
 254                         if (len > I2C_SMBUS_BLOCK_MAX)
 255                                 len = I2C_SMBUS_BLOCK_MAX;
 256                         outb_p(len, SMBHSTDAT0);
 257                         inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 258                         for (i = 1; i <= len; i++)
 259                                 outb_p(data->block[i], SMBBLKDAT);
 260                 }
 261                 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
 262                        VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
 263                 break;
 264         default:
 265                 goto exit_unsupported;
 266         }
 267
 268         outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
 269
 270         status = vt596_transaction(size);
 271         if (status)
 272                 return status;
 273
 274         if (size == VT596_PROC_CALL)
 275                 read_write = I2C_SMBUS_READ;
 276
 277         if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
 278                 return 0;
 279
 280         switch (size) {
 281         case VT596_BYTE:
 282         case VT596_BYTE_DATA:
 283                 data->byte = inb_p(SMBHSTDAT0);
 284                 break;
 285         case VT596_WORD_DATA:
 286         case VT596_PROC_CALL:
 287                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 288                 break;
 289         case VT596_I2C_BLOCK_DATA:
 290         case VT596_BLOCK_DATA:
 291                 data->block[0] = inb_p(SMBHSTDAT0);
 292                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 293                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 294                 inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 295                 for (i = 1; i <= data->block[0]; i++)
 296                         data->block[i] = inb_p(SMBBLKDAT);
 297                 break;
 298         }
 299         return 0;
 300
 301 exit_unsupported:
 302         dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n",
 303                  size);
 304         return -EOPNOTSUPP;
 305 }
 306
 307 static u32 vt596_func(struct i2c_adapter *adapter)
 308 {
 309         u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 310             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 311             I2C_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA;
 312
 313         if (vt596_features & FEATURE_I2CBLOCK)
 314                 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
 315         return func;
 316 }
 317
 318 static const struct i2c_algorithm smbus_algorithm = {
 319         .smbus_xfer     = vt596_access,
 320         .functionality  = vt596_func,
 321 };
 322
 323 static struct i2c_adapter vt596_adapter = {
 324         .owner          = THIS_MODULE,
 325         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 326         .algo           = &smbus_algorithm,
 327 };
 328
 329 static int __devinit vt596_probe(struct pci_dev *pdev,
 330                                  const struct pci_device_id *id)
 331 {
 332         unsigned char temp;
 333         int error = -ENODEV;
 334
 335         /* Determine the address of the SMBus areas */
 336         if (force_addr) {
 337                 vt596_smba = force_addr & 0xfff0;
 338                 force = 0;
 339                 goto found;
 340         }
 341
 342         if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
 343             !(vt596_smba & 0x0001)) {
 344                 /* try 2nd address and config reg. for 596 */
 345                 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
 346                     !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
 347                     (vt596_smba & 0x0001)) {
 348                         SMBHSTCFG = 0x84;
 349                 } else {
 350                         /* no matches at all */
 351                         dev_err(&pdev->dev, "Cannot configure "
 352                                 "SMBus I/O Base address\n");
 353                         return -ENODEV;
 354                 }
 355         }
 356
 357         vt596_smba &= 0xfff0;
 358         if (vt596_smba == 0) {
 359                 dev_err(&pdev->dev, "SMBus base address "
 360                         "uninitialized - upgrade BIOS or use "
 361                         "force_addr=0xaddr\n");
 362                 return -ENODEV;
 363         }
 364
 365 found:
 366         error = acpi_check_region(vt596_smba, 8, vt596_driver.name);
 367         if (error)
 368                 return -ENODEV;
 369
 370         if (!request_region(vt596_smba, 8, vt596_driver.name)) {
 371                 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
 372                         vt596_smba);
 373                 return -ENODEV;
 374         }
 375
 376         pci_read_config_byte(pdev, SMBHSTCFG, &temp);
 377         /* If force_addr is set, we program the new address here. Just to make
 378            sure, we disable the VT596 first. */
 379         if (force_addr) {
 380                 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
 381                 pci_write_config_word(pdev, id->driver_data, vt596_smba);
 382                 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 383                 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
 384                          "address 0x%04x!\n", vt596_smba);
 385         } else if (!(temp & 0x01)) {
 386                 if (force) {
 387                         /* NOTE: This assumes I/O space and other allocations
 388                          * WERE done by the Bios!  Don't complain if your
 389                          * hardware does weird things after enabling this.
 390                          * :') Check for Bios updates before resorting to
 391                          * this.
 392                          */
 393                         pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 394                         dev_info(&pdev->dev, "Enabling SMBus device\n");
 395                 } else {
 396                         dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
 397                                 "controller not enabled! - upgrade BIOS or "
 398                                 "use force=1\n");
 399                         goto release_region;
 400                 }
 401         }
 402
 403         dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
 404
 405         switch (pdev->device) {
 406         case PCI_DEVICE_ID_VIA_CX700:
 407         case PCI_DEVICE_ID_VIA_VX800:
 408         case PCI_DEVICE_ID_VIA_VX855:
 409         case PCI_DEVICE_ID_VIA_8251:
 410         case PCI_DEVICE_ID_VIA_8237:
 411         case PCI_DEVICE_ID_VIA_8237A:
 412         case PCI_DEVICE_ID_VIA_8237S:
 413         case PCI_DEVICE_ID_VIA_8235:
 414         case PCI_DEVICE_ID_VIA_8233A:
 415         case PCI_DEVICE_ID_VIA_8233_0:
 416                 vt596_features |= FEATURE_I2CBLOCK;
 417                 break;
 418         case PCI_DEVICE_ID_VIA_82C686_4:
 419                 /* The VT82C686B (rev 0x40) does support I2C block
 420                    transactions, but the VT82C686A (rev 0x30) doesn't */
 421                 if (pdev->revision >= 0x40)
 422                         vt596_features |= FEATURE_I2CBLOCK;
 423                 break;
 424         }
 425
 426         vt596_adapter.dev.parent = &pdev->dev;
 427         snprintf(vt596_adapter.name, sizeof(vt596_adapter.name),
 428                  "SMBus Via Pro adapter at %04x", vt596_smba);
 429
 430         vt596_pdev = pci_dev_get(pdev);
 431         if (i2c_add_adapter(&vt596_adapter)) {
 432                 pci_dev_put(vt596_pdev);
 433                 vt596_pdev = NULL;
 434         }
 435
 436         /* Always return failure here.  This is to allow other drivers to bind
 437          * to this pci device.  We don't really want to have control over the
 438          * pci device, we only wanted to read as few register values from it.
 439          */
 440         return -ENODEV;
 441
 442 release_region:
 443         release_region(vt596_smba, 8);
 444         return error;
 445 }
 446
 447 static struct pci_device_id vt596_ids[] = {
 448         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
 449           .driver_data = SMBBA1 },
 450         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
 451           .driver_data = SMBBA1 },
 452         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
 453           .driver_data = SMBBA1 },
 454         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
 455           .driver_data = SMBBA3 },
 456         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
 457           .driver_data = SMBBA3 },
 458         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
 459           .driver_data = SMBBA3 },
 460         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
 461           .driver_data = SMBBA3 },
 462         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
 463           .driver_data = SMBBA3 },
 464         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S),
 465           .driver_data = SMBBA3 },
 466         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
 467           .driver_data = SMBBA1 },
 468         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
 469           .driver_data = SMBBA3 },
 470         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
 471           .driver_data = SMBBA3 },
 472         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800),
 473           .driver_data = SMBBA3 },
 474         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855),
 475           .driver_data = SMBBA3 },
 476         { 0, }
 477 };
 478
 479 MODULE_DEVICE_TABLE(pci, vt596_ids);
 480
 481 static struct pci_driver vt596_driver = {
 482         .name           = "vt596_smbus",
 483         .id_table       = vt596_ids,
 484         .probe          = vt596_probe,
 485 };
 486
 487 static int __init i2c_vt596_init(void)
 488 {
 489         return pci_register_driver(&vt596_driver);
 490 }
 491
 492
 493 static void __exit i2c_vt596_exit(void)
 494 {
 495         pci_unregister_driver(&vt596_driver);
 496         if (vt596_pdev != NULL) {
 497                 i2c_del_adapter(&vt596_adapter);
 498                 release_region(vt596_smba, 8);
 499                 pci_dev_put(vt596_pdev);
 500                 vt596_pdev = NULL;
 501         }
 502 }
 503
 504 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
 505               "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
 506               "Jean Delvare <khali@linux-fr.org>");
 507 MODULE_DESCRIPTION("vt82c596 SMBus driver");
 508 MODULE_LICENSE("GPL");
 509
 510 module_init(i2c_vt596_init);
 511 module_exit(i2c_vt596_exit);