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  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
  38    Note: we assume there can only be one device, with one SMBus interface.
  39 */
  40
  41 #include <linux/module.h>
  42 #include <linux/delay.h>
  43 #include <linux/pci.h>
  44 #include <linux/kernel.h>
  45 #include <linux/stddef.h>
  46 #include <linux/ioport.h>
  47 #include <linux/i2c.h>
  48 #include <linux/init.h>
  49 #include <asm/io.h>
  50
  51 static struct pci_dev *vt596_pdev;
  52
  53 #define SMBBA1          0x90
  54 #define SMBBA2          0x80
  55 #define SMBBA3          0xD0
  56
  57 /* SMBus address offsets */
  58 static unsigned short vt596_smba;
  59 #define SMBHSTSTS       (vt596_smba + 0)
  60 #define SMBHSTCNT       (vt596_smba + 2)
  61 #define SMBHSTCMD       (vt596_smba + 3)
  62 #define SMBHSTADD       (vt596_smba + 4)
  63 #define SMBHSTDAT0      (vt596_smba + 5)
  64 #define SMBHSTDAT1      (vt596_smba + 6)
  65 #define SMBBLKDAT       (vt596_smba + 7)
  66
  67 /* PCI Address Constants */
  68
  69 /* SMBus data in configuration space can be found in two places,
  70    We try to select the better one */
  71
  72 static unsigned short SMBHSTCFG = 0xD2;
  73
  74 /* Other settings */
  75 #define MAX_TIMEOUT     500
  76
  77 /* VT82C596 constants */
  78 #define VT596_QUICK             0x00
  79 #define VT596_BYTE              0x04
  80 #define VT596_BYTE_DATA         0x08
  81 #define VT596_WORD_DATA         0x0C
  82 #define VT596_BLOCK_DATA        0x14
  83 #define VT596_I2C_BLOCK_DATA    0x34
  84
  85
  86 /* If force is set to anything different from 0, we forcibly enable the
  87    VT596. DANGEROUS! */
  88 static int force;
  89 module_param(force, bool, 0);
  90 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
  91
  92 /* If force_addr is set to anything different from 0, we forcibly enable
  93    the VT596 at the given address. VERY DANGEROUS! */
  94 static u16 force_addr;
  95 module_param(force_addr, ushort, 0);
  96 MODULE_PARM_DESC(force_addr,
  97                  "Forcibly enable the SMBus at the given address. "
  98                  "EXTREMELY DANGEROUS!");
  99
 100
 101 static struct pci_driver vt596_driver;
 102 static struct i2c_adapter vt596_adapter;
 103
 104 #define FEATURE_I2CBLOCK        (1<<0)
 105 static unsigned int vt596_features;
 106
 107 #ifdef DEBUG
 108 static void vt596_dump_regs(const char *msg, u8 size)
 109 {
 110         dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
 111                 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
 112                 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
 113                 inb_p(SMBHSTDAT1));
 114
 115         if (size == VT596_BLOCK_DATA
 116          || size == VT596_I2C_BLOCK_DATA) {
 117                 int i;
 118
 119                 dev_dbg(&vt596_adapter.dev, "BLK=");
 120                 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
 121                         printk("%02x,", inb_p(SMBBLKDAT));
 122                 printk("\n");
 123                 dev_dbg(&vt596_adapter.dev, "    ");
 124                 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
 125                         printk("%02x,", inb_p(SMBBLKDAT));
 126                 printk("%02x\n", inb_p(SMBBLKDAT));
 127         }
 128 }
 129 #else
 130 static inline void vt596_dump_regs(const char *msg, u8 size) { }
 131 #endif
 132
 133 /* Return -1 on error, 0 on success */
 134 static int vt596_transaction(u8 size)
 135 {
 136         int temp;
 137         int result = 0;
 138         int timeout = 0;
 139
 140         vt596_dump_regs("Transaction (pre)", size);
 141
 142         /* Make sure the SMBus host is ready to start transmitting */
 143         if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 144                 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
 145                         "Resetting...\n", temp);
 146
 147                 outb_p(temp, SMBHSTSTS);
 148                 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 149                         dev_err(&vt596_adapter.dev, "SMBus reset failed! "
 150                                 "(0x%02x)\n", temp);
 151                         return -1;
 152                 }
 153         }
 154
 155         /* Start the transaction by setting bit 6 */
 156         outb_p(0x40 | size, SMBHSTCNT);
 157
 158         /* We will always wait for a fraction of a second */
 159         do {
 160                 msleep(1);
 161                 temp = inb_p(SMBHSTSTS);
 162         } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
 163
 164         /* If the SMBus is still busy, we give up */
 165         if (timeout >= MAX_TIMEOUT) {
 166                 result = -1;
 167                 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
 168         }
 169
 170         if (temp & 0x10) {
 171                 result = -1;
 172                 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
 173                         size);
 174         }
 175
 176         if (temp & 0x08) {
 177                 result = -1;
 178                 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
 179         }
 180
 181         if (temp & 0x04) {
 182                 int read = inb_p(SMBHSTADD) & 0x01;
 183                 result = -1;
 184                 /* The quick and receive byte commands are used to probe
 185                    for chips, so errors are expected, and we don't want
 186                    to frighten the user. */
 187                 if (!((size == VT596_QUICK && !read) ||
 188                       (size == VT596_BYTE && read)))
 189                         dev_err(&vt596_adapter.dev, "Transaction error!\n");
 190         }
 191
 192         /* Resetting status register */
 193         if (temp & 0x1F)
 194                 outb_p(temp, SMBHSTSTS);
 195
 196         vt596_dump_regs("Transaction (post)", size);
 197
 198         return result;
 199 }
 200
 201 /* Return -1 on error, 0 on success */
 202 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
 203                 unsigned short flags, char read_write, u8 command,
 204                 int size, union i2c_smbus_data *data)
 205 {
 206         int i;
 207
 208         switch (size) {
 209         case I2C_SMBUS_QUICK:
 210                 size = VT596_QUICK;
 211                 break;
 212         case I2C_SMBUS_BYTE:
 213                 if (read_write == I2C_SMBUS_WRITE)
 214                         outb_p(command, SMBHSTCMD);
 215                 size = VT596_BYTE;
 216                 break;
 217         case I2C_SMBUS_BYTE_DATA:
 218                 outb_p(command, SMBHSTCMD);
 219                 if (read_write == I2C_SMBUS_WRITE)
 220                         outb_p(data->byte, SMBHSTDAT0);
 221                 size = VT596_BYTE_DATA;
 222                 break;
 223         case I2C_SMBUS_WORD_DATA:
 224                 outb_p(command, SMBHSTCMD);
 225                 if (read_write == I2C_SMBUS_WRITE) {
 226                         outb_p(data->word & 0xff, SMBHSTDAT0);
 227                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 228                 }
 229                 size = VT596_WORD_DATA;
 230                 break;
 231         case I2C_SMBUS_I2C_BLOCK_DATA:
 232                 if (!(vt596_features & FEATURE_I2CBLOCK))
 233                         goto exit_unsupported;
 234                 if (read_write == I2C_SMBUS_READ)
 235                         outb_p(I2C_SMBUS_BLOCK_MAX, SMBHSTDAT0);
 236                 /* Fall through */
 237         case I2C_SMBUS_BLOCK_DATA:
 238                 outb_p(command, SMBHSTCMD);
 239                 if (read_write == I2C_SMBUS_WRITE) {
 240                         u8 len = data->block[0];
 241                         if (len > I2C_SMBUS_BLOCK_MAX)
 242                                 len = I2C_SMBUS_BLOCK_MAX;
 243                         outb_p(len, SMBHSTDAT0);
 244                         inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 245                         for (i = 1; i <= len; i++)
 246                                 outb_p(data->block[i], SMBBLKDAT);
 247                 }
 248                 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
 249                        VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
 250                 break;
 251         default:
 252                 goto exit_unsupported;
 253         }
 254
 255         outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
 256
 257         if (vt596_transaction(size)) /* Error in transaction */
 258                 return -1;
 259
 260         if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
 261                 return 0;
 262
 263         switch (size) {
 264         case VT596_BYTE:
 265         case VT596_BYTE_DATA:
 266                 data->byte = inb_p(SMBHSTDAT0);
 267                 break;
 268         case VT596_WORD_DATA:
 269                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 270                 break;
 271         case VT596_I2C_BLOCK_DATA:
 272         case VT596_BLOCK_DATA:
 273                 data->block[0] = inb_p(SMBHSTDAT0);
 274                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 275                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 276                 inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 277                 for (i = 1; i <= data->block[0]; i++)
 278                         data->block[i] = inb_p(SMBBLKDAT);
 279                 break;
 280         }
 281         return 0;
 282
 283 exit_unsupported:
 284         dev_warn(&vt596_adapter.dev, "Unsupported command invoked! (0x%02x)\n",
 285                  size);
 286         return -1;
 287 }
 288
 289 static u32 vt596_func(struct i2c_adapter *adapter)
 290 {
 291         u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 292             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 293             I2C_FUNC_SMBUS_BLOCK_DATA;
 294
 295         if (vt596_features & FEATURE_I2CBLOCK)
 296                 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
 297         return func;
 298 }
 299
 300 static struct i2c_algorithm smbus_algorithm = {
 301         .smbus_xfer     = vt596_access,
 302         .functionality  = vt596_func,
 303 };
 304
 305 static struct i2c_adapter vt596_adapter = {
 306         .owner          = THIS_MODULE,
 307         .class          = I2C_CLASS_HWMON,
 308         .algo           = &smbus_algorithm,
 309 };
 310
 311 static int __devinit vt596_probe(struct pci_dev *pdev,
 312                                  const struct pci_device_id *id)
 313 {
 314         unsigned char temp;
 315         int error = -ENODEV;
 316
 317         /* Determine the address of the SMBus areas */
 318         if (force_addr) {
 319                 vt596_smba = force_addr & 0xfff0;
 320                 force = 0;
 321                 goto found;
 322         }
 323
 324         if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
 325             !(vt596_smba & 0x0001)) {
 326                 /* try 2nd address and config reg. for 596 */
 327                 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
 328                     !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
 329                     (vt596_smba & 0x0001)) {
 330                         SMBHSTCFG = 0x84;
 331                 } else {
 332                         /* no matches at all */
 333                         dev_err(&pdev->dev, "Cannot configure "
 334                                 "SMBus I/O Base address\n");
 335                         return -ENODEV;
 336                 }
 337         }
 338
 339         vt596_smba &= 0xfff0;
 340         if (vt596_smba == 0) {
 341                 dev_err(&pdev->dev, "SMBus base address "
 342                         "uninitialized - upgrade BIOS or use "
 343                         "force_addr=0xaddr\n");
 344                 return -ENODEV;
 345         }
 346
 347 found:
 348         if (!request_region(vt596_smba, 8, vt596_driver.name)) {
 349                 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
 350                         vt596_smba);
 351                 return -ENODEV;
 352         }
 353
 354         pci_read_config_byte(pdev, SMBHSTCFG, &temp);
 355         /* If force_addr is set, we program the new address here. Just to make
 356            sure, we disable the VT596 first. */
 357         if (force_addr) {
 358                 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
 359                 pci_write_config_word(pdev, id->driver_data, vt596_smba);
 360                 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 361                 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
 362                          "address 0x%04x!\n", vt596_smba);
 363         } else if (!(temp & 0x01)) {
 364                 if (force) {
 365                         /* NOTE: This assumes I/O space and other allocations
 366                          * WERE done by the Bios!  Don't complain if your
 367                          * hardware does weird things after enabling this.
 368                          * :') Check for Bios updates before resorting to
 369                          * this.
 370                          */
 371                         pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 372                         dev_info(&pdev->dev, "Enabling SMBus device\n");
 373                 } else {
 374                         dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
 375                                 "controller not enabled! - upgrade BIOS or "
 376                                 "use force=1\n");
 377                         goto release_region;
 378                 }
 379         }
 380
 381         dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
 382
 383         switch (pdev->device) {
 384         case PCI_DEVICE_ID_VIA_8237:
 385         case PCI_DEVICE_ID_VIA_8235:
 386         case PCI_DEVICE_ID_VIA_8233A:
 387         case PCI_DEVICE_ID_VIA_8233_0:
 388                 vt596_features |= FEATURE_I2CBLOCK;
 389                 break;
 390         case PCI_DEVICE_ID_VIA_82C686_4:
 391                 /* The VT82C686B (rev 0x40) does support I2C block
 392                    transactions, but the VT82C686A (rev 0x30) doesn't */
 393                 if (!pci_read_config_byte(pdev, PCI_REVISION_ID, &temp)
 394                  && temp >= 0x40)
 395                         vt596_features |= FEATURE_I2CBLOCK;
 396                 break;
 397         }
 398
 399         vt596_adapter.dev.parent = &pdev->dev;
 400         snprintf(vt596_adapter.name, I2C_NAME_SIZE,
 401                  "SMBus Via Pro adapter at %04x", vt596_smba);
 402
 403         vt596_pdev = pci_dev_get(pdev);
 404         if (i2c_add_adapter(&vt596_adapter)) {
 405                 pci_dev_put(vt596_pdev);
 406                 vt596_pdev = NULL;
 407         }
 408
 409         /* Always return failure here.  This is to allow other drivers to bind
 410          * to this pci device.  We don't really want to have control over the
 411          * pci device, we only wanted to read as few register values from it.
 412          */
 413         return -ENODEV;
 414
 415 release_region:
 416         release_region(vt596_smba, 8);
 417         return error;
 418 }
 419
 420 static struct pci_device_id vt596_ids[] = {
 421         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
 422           .driver_data = SMBBA1 },
 423         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
 424           .driver_data = SMBBA1 },
 425         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
 426           .driver_data = SMBBA1 },
 427         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
 428           .driver_data = SMBBA3 },
 429         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
 430           .driver_data = SMBBA3 },
 431         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
 432           .driver_data = SMBBA3 },
 433         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
 434           .driver_data = SMBBA3 },
 435         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
 436           .driver_data = SMBBA1 },
 437         { 0, }
 438 };
 439
 440 MODULE_DEVICE_TABLE(pci, vt596_ids);
 441
 442 static struct pci_driver vt596_driver = {
 443         .name           = "vt596_smbus",
 444         .id_table       = vt596_ids,
 445         .probe          = vt596_probe,
 446 };
 447
 448 static int __init i2c_vt596_init(void)
 449 {
 450         return pci_register_driver(&vt596_driver);
 451 }
 452
 453
 454 static void __exit i2c_vt596_exit(void)
 455 {
 456         pci_unregister_driver(&vt596_driver);
 457         if (vt596_pdev != NULL) {
 458                 i2c_del_adapter(&vt596_adapter);
 459                 release_region(vt596_smba, 8);
 460                 pci_dev_put(vt596_pdev);
 461                 vt596_pdev = NULL;
 462         }
 463 }
 464
 465 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
 466               "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
 467               "Jean Delvare <khali@linux-fr.org>");
 468 MODULE_DESCRIPTION("vt82c596 SMBus driver");
 469 MODULE_LICENSE("GPL");
 470
 471 module_init(i2c_vt596_init);
 472 module_exit(i2c_vt596_exit);