drivers/i2c/busses/i2c-viapro.c

   1 /*
   2     i2c-viapro.c - Part of lm_sensors, Linux kernel modules for hardware
   3               monitoring
   4     Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
   5     Philip Edelbrock <phil@netroedge.com>, Kyösti Mälkki <kmalkki@cc.hut.fi>,
   6     Mark D. Studebaker <mdsxyz123@yahoo.com>
   7     Copyright (C) 2005 - 2007  Jean Delvare <khali@linux-fr.org>
   8
   9     This program is free software; you can redistribute it and/or modify
  10     it under the terms of the GNU General Public License as published by
  11     the Free Software Foundation; either version 2 of the License, or
  12     (at your option) any later version.
  13
  14     This program is distributed in the hope that it will be useful,
  15     but WITHOUT ANY WARRANTY; without even the implied warranty of
  16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17     GNU General Public License for more details.
  18
  19     You should have received a copy of the GNU General Public License
  20     along with this program; if not, write to the Free Software
  21     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 /*
  25    Supports the following VIA south bridges:
  26
  27    Chip name          PCI ID  REV     I2C block
  28    VT82C596A          0x3050             no
  29    VT82C596B          0x3051             no
  30    VT82C686A          0x3057  0x30       no
  31    VT82C686B          0x3057  0x40       yes
  32    VT8231             0x8235             no?
  33    VT8233             0x3074             yes
  34    VT8233A            0x3147             yes?
  35    VT8235             0x3177             yes
  36    VT8237R            0x3227             yes
  37    VT8237A            0x3337             yes
  38    VT8251             0x3287             yes
  39    CX700              0x8324             yes
  40
  41    Note: we assume there can only be one device, with one SMBus interface.
  42 */
  43
  44 #include <linux/module.h>
  45 #include <linux/delay.h>
  46 #include <linux/pci.h>
  47 #include <linux/kernel.h>
  48 #include <linux/stddef.h>
  49 #include <linux/ioport.h>
  50 #include <linux/i2c.h>
  51 #include <linux/init.h>
  52 #include <asm/io.h>
  53
  54 static struct pci_dev *vt596_pdev;
  55
  56 #define SMBBA1          0x90
  57 #define SMBBA2          0x80
  58 #define SMBBA3          0xD0
  59
  60 /* SMBus address offsets */
  61 static unsigned short vt596_smba;
  62 #define SMBHSTSTS       (vt596_smba + 0)
  63 #define SMBHSTCNT       (vt596_smba + 2)
  64 #define SMBHSTCMD       (vt596_smba + 3)
  65 #define SMBHSTADD       (vt596_smba + 4)
  66 #define SMBHSTDAT0      (vt596_smba + 5)
  67 #define SMBHSTDAT1      (vt596_smba + 6)
  68 #define SMBBLKDAT       (vt596_smba + 7)
  69
  70 /* PCI Address Constants */
  71
  72 /* SMBus data in configuration space can be found in two places,
  73    We try to select the better one */
  74
  75 static unsigned short SMBHSTCFG = 0xD2;
  76
  77 /* Other settings */
  78 #define MAX_TIMEOUT     500
  79
  80 /* VT82C596 constants */
  81 #define VT596_QUICK             0x00
  82 #define VT596_BYTE              0x04
  83 #define VT596_BYTE_DATA         0x08
  84 #define VT596_WORD_DATA         0x0C
  85 #define VT596_BLOCK_DATA        0x14
  86 #define VT596_I2C_BLOCK_DATA    0x34
  87
  88
  89 /* If force is set to anything different from 0, we forcibly enable the
  90    VT596. DANGEROUS! */
  91 static int force;
  92 module_param(force, bool, 0);
  93 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
  94
  95 /* If force_addr is set to anything different from 0, we forcibly enable
  96    the VT596 at the given address. VERY DANGEROUS! */
  97 static u16 force_addr;
  98 module_param(force_addr, ushort, 0);
  99 MODULE_PARM_DESC(force_addr,
 100                  "Forcibly enable the SMBus at the given address. "
 101                  "EXTREMELY DANGEROUS!");
 102
 103
 104 static struct pci_driver vt596_driver;
 105 static struct i2c_adapter vt596_adapter;
 106
 107 #define FEATURE_I2CBLOCK        (1<<0)
 108 static unsigned int vt596_features;
 109
 110 #ifdef DEBUG
 111 static void vt596_dump_regs(const char *msg, u8 size)
 112 {
 113         dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
 114                 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
 115                 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
 116                 inb_p(SMBHSTDAT1));
 117
 118         if (size == VT596_BLOCK_DATA
 119          || size == VT596_I2C_BLOCK_DATA) {
 120                 int i;
 121
 122                 dev_dbg(&vt596_adapter.dev, "BLK=");
 123                 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
 124                         printk("%02x,", inb_p(SMBBLKDAT));
 125                 printk("\n");
 126                 dev_dbg(&vt596_adapter.dev, "    ");
 127                 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
 128                         printk("%02x,", inb_p(SMBBLKDAT));
 129                 printk("%02x\n", inb_p(SMBBLKDAT));
 130         }
 131 }
 132 #else
 133 static inline void vt596_dump_regs(const char *msg, u8 size) { }
 134 #endif
 135
 136 /* Return -1 on error, 0 on success */
 137 static int vt596_transaction(u8 size)
 138 {
 139         int temp;
 140         int result = 0;
 141         int timeout = 0;
 142
 143         vt596_dump_regs("Transaction (pre)", size);
 144
 145         /* Make sure the SMBus host is ready to start transmitting */
 146         if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 147                 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
 148                         "Resetting...\n", temp);
 149
 150                 outb_p(temp, SMBHSTSTS);
 151                 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 152                         dev_err(&vt596_adapter.dev, "SMBus reset failed! "
 153                                 "(0x%02x)\n", temp);
 154                         return -1;
 155                 }
 156         }
 157
 158         /* Start the transaction by setting bit 6 */
 159         outb_p(0x40 | size, SMBHSTCNT);
 160
 161         /* We will always wait for a fraction of a second */
 162         do {
 163                 msleep(1);
 164                 temp = inb_p(SMBHSTSTS);
 165         } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
 166
 167         /* If the SMBus is still busy, we give up */
 168         if (timeout >= MAX_TIMEOUT) {
 169                 result = -1;
 170                 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
 171         }
 172
 173         if (temp & 0x10) {
 174                 result = -1;
 175                 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
 176                         size);
 177         }
 178
 179         if (temp & 0x08) {
 180                 result = -1;
 181                 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
 182         }
 183
 184         if (temp & 0x04) {
 185                 int read = inb_p(SMBHSTADD) & 0x01;
 186                 result = -1;
 187                 /* The quick and receive byte commands are used to probe
 188                    for chips, so errors are expected, and we don't want
 189                    to frighten the user. */
 190                 if (!((size == VT596_QUICK && !read) ||
 191                       (size == VT596_BYTE && read)))
 192                         dev_err(&vt596_adapter.dev, "Transaction error!\n");
 193         }
 194
 195         /* Resetting status register */
 196         if (temp & 0x1F)
 197                 outb_p(temp, SMBHSTSTS);
 198
 199         vt596_dump_regs("Transaction (post)", size);
 200
 201         return result;
 202 }
 203
 204 /* Return -1 on error, 0 on success */
 205 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
 206                 unsigned short flags, char read_write, u8 command,
 207                 int size, union i2c_smbus_data *data)
 208 {
 209         int i;
 210
 211         switch (size) {
 212         case I2C_SMBUS_QUICK:
 213                 size = VT596_QUICK;
 214                 break;
 215         case I2C_SMBUS_BYTE:
 216                 if (read_write == I2C_SMBUS_WRITE)
 217                         outb_p(command, SMBHSTCMD);
 218                 size = VT596_BYTE;
 219                 break;
 220         case I2C_SMBUS_BYTE_DATA:
 221                 outb_p(command, SMBHSTCMD);
 222                 if (read_write == I2C_SMBUS_WRITE)
 223                         outb_p(data->byte, SMBHSTDAT0);
 224                 size = VT596_BYTE_DATA;
 225                 break;
 226         case I2C_SMBUS_WORD_DATA:
 227                 outb_p(command, SMBHSTCMD);
 228                 if (read_write == I2C_SMBUS_WRITE) {
 229                         outb_p(data->word & 0xff, SMBHSTDAT0);
 230                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 231                 }
 232                 size = VT596_WORD_DATA;
 233                 break;
 234         case I2C_SMBUS_I2C_BLOCK_DATA:
 235                 if (!(vt596_features & FEATURE_I2CBLOCK))
 236                         goto exit_unsupported;
 237                 if (read_write == I2C_SMBUS_READ)
 238                         outb_p(data->block[0], SMBHSTDAT0);
 239                 /* Fall through */
 240         case I2C_SMBUS_BLOCK_DATA:
 241                 outb_p(command, SMBHSTCMD);
 242                 if (read_write == I2C_SMBUS_WRITE) {
 243                         u8 len = data->block[0];
 244                         if (len > I2C_SMBUS_BLOCK_MAX)
 245                                 len = I2C_SMBUS_BLOCK_MAX;
 246                         outb_p(len, SMBHSTDAT0);
 247                         inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 248                         for (i = 1; i <= len; i++)
 249                                 outb_p(data->block[i], SMBBLKDAT);
 250                 }
 251                 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
 252                        VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
 253                 break;
 254         default:
 255                 goto exit_unsupported;
 256         }
 257
 258         outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
 259
 260         if (vt596_transaction(size)) /* Error in transaction */
 261                 return -1;
 262
 263         if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
 264                 return 0;
 265
 266         switch (size) {
 267         case VT596_BYTE:
 268         case VT596_BYTE_DATA:
 269                 data->byte = inb_p(SMBHSTDAT0);
 270                 break;
 271         case VT596_WORD_DATA:
 272                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 273                 break;
 274         case VT596_I2C_BLOCK_DATA:
 275         case VT596_BLOCK_DATA:
 276                 data->block[0] = inb_p(SMBHSTDAT0);
 277                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 278                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 279                 inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 280                 for (i = 1; i <= data->block[0]; i++)
 281                         data->block[i] = inb_p(SMBBLKDAT);
 282                 break;
 283         }
 284         return 0;
 285
 286 exit_unsupported:
 287         dev_warn(&vt596_adapter.dev, "Unsupported command invoked! (0x%02x)\n",
 288                  size);
 289         return -1;
 290 }
 291
 292 static u32 vt596_func(struct i2c_adapter *adapter)
 293 {
 294         u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 295             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 296             I2C_FUNC_SMBUS_BLOCK_DATA;
 297
 298         if (vt596_features & FEATURE_I2CBLOCK)
 299                 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
 300         return func;
 301 }
 302
 303 static const struct i2c_algorithm smbus_algorithm = {
 304         .smbus_xfer     = vt596_access,
 305         .functionality  = vt596_func,
 306 };
 307
 308 static struct i2c_adapter vt596_adapter = {
 309         .owner          = THIS_MODULE,
 310         .id             = I2C_HW_SMBUS_VIA2,
 311         .class          = I2C_CLASS_HWMON,
 312         .algo           = &smbus_algorithm,
 313 };
 314
 315 static int __devinit vt596_probe(struct pci_dev *pdev,
 316                                  const struct pci_device_id *id)
 317 {
 318         unsigned char temp;
 319         int error = -ENODEV;
 320
 321         /* Determine the address of the SMBus areas */
 322         if (force_addr) {
 323                 vt596_smba = force_addr & 0xfff0;
 324                 force = 0;
 325                 goto found;
 326         }
 327
 328         if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
 329             !(vt596_smba & 0x0001)) {
 330                 /* try 2nd address and config reg. for 596 */
 331                 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
 332                     !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
 333                     (vt596_smba & 0x0001)) {
 334                         SMBHSTCFG = 0x84;
 335                 } else {
 336                         /* no matches at all */
 337                         dev_err(&pdev->dev, "Cannot configure "
 338                                 "SMBus I/O Base address\n");
 339                         return -ENODEV;
 340                 }
 341         }
 342
 343         vt596_smba &= 0xfff0;
 344         if (vt596_smba == 0) {
 345                 dev_err(&pdev->dev, "SMBus base address "
 346                         "uninitialized - upgrade BIOS or use "
 347                         "force_addr=0xaddr\n");
 348                 return -ENODEV;
 349         }
 350
 351 found:
 352         if (!request_region(vt596_smba, 8, vt596_driver.name)) {
 353                 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
 354                         vt596_smba);
 355                 return -ENODEV;
 356         }
 357
 358         pci_read_config_byte(pdev, SMBHSTCFG, &temp);
 359         /* If force_addr is set, we program the new address here. Just to make
 360            sure, we disable the VT596 first. */
 361         if (force_addr) {
 362                 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
 363                 pci_write_config_word(pdev, id->driver_data, vt596_smba);
 364                 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 365                 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
 366                          "address 0x%04x!\n", vt596_smba);
 367         } else if (!(temp & 0x01)) {
 368                 if (force) {
 369                         /* NOTE: This assumes I/O space and other allocations
 370                          * WERE done by the Bios!  Don't complain if your
 371                          * hardware does weird things after enabling this.
 372                          * :') Check for Bios updates before resorting to
 373                          * this.
 374                          */
 375                         pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 376                         dev_info(&pdev->dev, "Enabling SMBus device\n");
 377                 } else {
 378                         dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
 379                                 "controller not enabled! - upgrade BIOS or "
 380                                 "use force=1\n");
 381                         goto release_region;
 382                 }
 383         }
 384
 385         dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
 386
 387         switch (pdev->device) {
 388         case PCI_DEVICE_ID_VIA_CX700:
 389         case PCI_DEVICE_ID_VIA_8251:
 390         case PCI_DEVICE_ID_VIA_8237:
 391         case PCI_DEVICE_ID_VIA_8237A:
 392         case PCI_DEVICE_ID_VIA_8235:
 393         case PCI_DEVICE_ID_VIA_8233A:
 394         case PCI_DEVICE_ID_VIA_8233_0:
 395                 vt596_features |= FEATURE_I2CBLOCK;
 396                 break;
 397         case PCI_DEVICE_ID_VIA_82C686_4:
 398                 /* The VT82C686B (rev 0x40) does support I2C block
 399                    transactions, but the VT82C686A (rev 0x30) doesn't */
 400                 if (pdev->revision >= 0x40)
 401                         vt596_features |= FEATURE_I2CBLOCK;
 402                 break;
 403         }
 404
 405         vt596_adapter.dev.parent = &pdev->dev;
 406         snprintf(vt596_adapter.name, sizeof(vt596_adapter.name),
 407                  "SMBus Via Pro adapter at %04x", vt596_smba);
 408
 409         vt596_pdev = pci_dev_get(pdev);
 410         if (i2c_add_adapter(&vt596_adapter)) {
 411                 pci_dev_put(vt596_pdev);
 412                 vt596_pdev = NULL;
 413         }
 414
 415         /* Always return failure here.  This is to allow other drivers to bind
 416          * to this pci device.  We don't really want to have control over the
 417          * pci device, we only wanted to read as few register values from it.
 418          */
 419         return -ENODEV;
 420
 421 release_region:
 422         release_region(vt596_smba, 8);
 423         return error;
 424 }
 425
 426 static struct pci_device_id vt596_ids[] = {
 427         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
 428           .driver_data = SMBBA1 },
 429         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
 430           .driver_data = SMBBA1 },
 431         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
 432           .driver_data = SMBBA1 },
 433         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
 434           .driver_data = SMBBA3 },
 435         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
 436           .driver_data = SMBBA3 },
 437         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
 438           .driver_data = SMBBA3 },
 439         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
 440           .driver_data = SMBBA3 },
 441         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
 442           .driver_data = SMBBA3 },
 443         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
 444           .driver_data = SMBBA1 },
 445         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
 446           .driver_data = SMBBA3 },
 447         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
 448           .driver_data = SMBBA3 },
 449         { 0, }
 450 };
 451
 452 MODULE_DEVICE_TABLE(pci, vt596_ids);
 453
 454 static struct pci_driver vt596_driver = {
 455         .name           = "vt596_smbus",
 456         .id_table       = vt596_ids,
 457         .probe          = vt596_probe,
 458 };
 459
 460 static int __init i2c_vt596_init(void)
 461 {
 462         return pci_register_driver(&vt596_driver);
 463 }
 464
 465
 466 static void __exit i2c_vt596_exit(void)
 467 {
 468         pci_unregister_driver(&vt596_driver);
 469         if (vt596_pdev != NULL) {
 470                 i2c_del_adapter(&vt596_adapter);
 471                 release_region(vt596_smba, 8);
 472                 pci_dev_put(vt596_pdev);
 473                 vt596_pdev = NULL;
 474         }
 475 }
 476
 477 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
 478               "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
 479               "Jean Delvare <khali@linux-fr.org>");
 480 MODULE_DESCRIPTION("vt82c596 SMBus driver");
 481 MODULE_LICENSE("GPL");
 482
 483 module_init(i2c_vt596_init);
 484 module_exit(i2c_vt596_exit);