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 <linux/acpi.h>
  53 #include <asm/io.h>
  54
  55 static struct pci_dev *vt596_pdev;
  56
  57 #define SMBBA1          0x90
  58 #define SMBBA2          0x80
  59 #define SMBBA3          0xD0
  60
  61 /* SMBus address offsets */
  62 static unsigned short vt596_smba;
  63 #define SMBHSTSTS       (vt596_smba + 0)
  64 #define SMBHSTCNT       (vt596_smba + 2)
  65 #define SMBHSTCMD       (vt596_smba + 3)
  66 #define SMBHSTADD       (vt596_smba + 4)
  67 #define SMBHSTDAT0      (vt596_smba + 5)
  68 #define SMBHSTDAT1      (vt596_smba + 6)
  69 #define SMBBLKDAT       (vt596_smba + 7)
  70
  71 /* PCI Address Constants */
  72
  73 /* SMBus data in configuration space can be found in two places,
  74    We try to select the better one */
  75
  76 static unsigned short SMBHSTCFG = 0xD2;
  77
  78 /* Other settings */
  79 #define MAX_TIMEOUT     500
  80
  81 /* VT82C596 constants */
  82 #define VT596_QUICK             0x00
  83 #define VT596_BYTE              0x04
  84 #define VT596_BYTE_DATA         0x08
  85 #define VT596_WORD_DATA         0x0C
  86 #define VT596_BLOCK_DATA        0x14
  87 #define VT596_I2C_BLOCK_DATA    0x34
  88
  89
  90 /* If force is set to anything different from 0, we forcibly enable the
  91    VT596. DANGEROUS! */
  92 static int force;
  93 module_param(force, bool, 0);
  94 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
  95
  96 /* If force_addr is set to anything different from 0, we forcibly enable
  97    the VT596 at the given address. VERY DANGEROUS! */
  98 static u16 force_addr;
  99 module_param(force_addr, ushort, 0);
 100 MODULE_PARM_DESC(force_addr,
 101                  "Forcibly enable the SMBus at the given address. "
 102                  "EXTREMELY DANGEROUS!");
 103
 104
 105 static struct pci_driver vt596_driver;
 106 static struct i2c_adapter vt596_adapter;
 107
 108 #define FEATURE_I2CBLOCK        (1<<0)
 109 static unsigned int vt596_features;
 110
 111 #ifdef DEBUG
 112 static void vt596_dump_regs(const char *msg, u8 size)
 113 {
 114         dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
 115                 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
 116                 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
 117                 inb_p(SMBHSTDAT1));
 118
 119         if (size == VT596_BLOCK_DATA
 120          || size == VT596_I2C_BLOCK_DATA) {
 121                 int i;
 122
 123                 dev_dbg(&vt596_adapter.dev, "BLK=");
 124                 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
 125                         printk("%02x,", inb_p(SMBBLKDAT));
 126                 printk("\n");
 127                 dev_dbg(&vt596_adapter.dev, "    ");
 128                 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
 129                         printk("%02x,", inb_p(SMBBLKDAT));
 130                 printk("%02x\n", inb_p(SMBBLKDAT));
 131         }
 132 }
 133 #else
 134 static inline void vt596_dump_regs(const char *msg, u8 size) { }
 135 #endif
 136
 137 /* Return -1 on error, 0 on success */
 138 static int vt596_transaction(u8 size)
 139 {
 140         int temp;
 141         int result = 0;
 142         int timeout = 0;
 143
 144         vt596_dump_regs("Transaction (pre)", size);
 145
 146         /* Make sure the SMBus host is ready to start transmitting */
 147         if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 148                 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
 149                         "Resetting...\n", temp);
 150
 151                 outb_p(temp, SMBHSTSTS);
 152                 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 153                         dev_err(&vt596_adapter.dev, "SMBus reset failed! "
 154                                 "(0x%02x)\n", temp);
 155                         return -1;
 156                 }
 157         }
 158
 159         /* Start the transaction by setting bit 6 */
 160         outb_p(0x40 | size, SMBHSTCNT);
 161
 162         /* We will always wait for a fraction of a second */
 163         do {
 164                 msleep(1);
 165                 temp = inb_p(SMBHSTSTS);
 166         } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
 167
 168         /* If the SMBus is still busy, we give up */
 169         if (timeout >= MAX_TIMEOUT) {
 170                 result = -1;
 171                 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
 172         }
 173
 174         if (temp & 0x10) {
 175                 result = -1;
 176                 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
 177                         size);
 178         }
 179
 180         if (temp & 0x08) {
 181                 result = -1;
 182                 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
 183         }
 184
 185         if (temp & 0x04) {
 186                 int read = inb_p(SMBHSTADD) & 0x01;
 187                 result = -1;
 188                 /* The quick and receive byte commands are used to probe
 189                    for chips, so errors are expected, and we don't want
 190                    to frighten the user. */
 191                 if (!((size == VT596_QUICK && !read) ||
 192                       (size == VT596_BYTE && read)))
 193                         dev_err(&vt596_adapter.dev, "Transaction error!\n");
 194         }
 195
 196         /* Resetting status register */
 197         if (temp & 0x1F)
 198                 outb_p(temp, SMBHSTSTS);
 199
 200         vt596_dump_regs("Transaction (post)", size);
 201
 202         return result;
 203 }
 204
 205 /* Return -1 on error, 0 on success */
 206 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
 207                 unsigned short flags, char read_write, u8 command,
 208                 int size, union i2c_smbus_data *data)
 209 {
 210         int i;
 211
 212         switch (size) {
 213         case I2C_SMBUS_QUICK:
 214                 size = VT596_QUICK;
 215                 break;
 216         case I2C_SMBUS_BYTE:
 217                 if (read_write == I2C_SMBUS_WRITE)
 218                         outb_p(command, SMBHSTCMD);
 219                 size = VT596_BYTE;
 220                 break;
 221         case I2C_SMBUS_BYTE_DATA:
 222                 outb_p(command, SMBHSTCMD);
 223                 if (read_write == I2C_SMBUS_WRITE)
 224                         outb_p(data->byte, SMBHSTDAT0);
 225                 size = VT596_BYTE_DATA;
 226                 break;
 227         case I2C_SMBUS_WORD_DATA:
 228                 outb_p(command, SMBHSTCMD);
 229                 if (read_write == I2C_SMBUS_WRITE) {
 230                         outb_p(data->word & 0xff, SMBHSTDAT0);
 231                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 232                 }
 233                 size = VT596_WORD_DATA;
 234                 break;
 235         case I2C_SMBUS_I2C_BLOCK_DATA:
 236                 if (!(vt596_features & FEATURE_I2CBLOCK))
 237                         goto exit_unsupported;
 238                 if (read_write == I2C_SMBUS_READ)
 239                         outb_p(data->block[0], SMBHSTDAT0);
 240                 /* Fall through */
 241         case I2C_SMBUS_BLOCK_DATA:
 242                 outb_p(command, SMBHSTCMD);
 243                 if (read_write == I2C_SMBUS_WRITE) {
 244                         u8 len = data->block[0];
 245                         if (len > I2C_SMBUS_BLOCK_MAX)
 246                                 len = I2C_SMBUS_BLOCK_MAX;
 247                         outb_p(len, SMBHSTDAT0);
 248                         inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 249                         for (i = 1; i <= len; i++)
 250                                 outb_p(data->block[i], SMBBLKDAT);
 251                 }
 252                 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
 253                        VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
 254                 break;
 255         default:
 256                 goto exit_unsupported;
 257         }
 258
 259         outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
 260
 261         if (vt596_transaction(size)) /* Error in transaction */
 262                 return -1;
 263
 264         if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
 265                 return 0;
 266
 267         switch (size) {
 268         case VT596_BYTE:
 269         case VT596_BYTE_DATA:
 270                 data->byte = inb_p(SMBHSTDAT0);
 271                 break;
 272         case VT596_WORD_DATA:
 273                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 274                 break;
 275         case VT596_I2C_BLOCK_DATA:
 276         case VT596_BLOCK_DATA:
 277                 data->block[0] = inb_p(SMBHSTDAT0);
 278                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 279                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 280                 inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 281                 for (i = 1; i <= data->block[0]; i++)
 282                         data->block[i] = inb_p(SMBBLKDAT);
 283                 break;
 284         }
 285         return 0;
 286
 287 exit_unsupported:
 288         dev_warn(&vt596_adapter.dev, "Unsupported command invoked! (0x%02x)\n",
 289                  size);
 290         return -1;
 291 }
 292
 293 static u32 vt596_func(struct i2c_adapter *adapter)
 294 {
 295         u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 296             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 297             I2C_FUNC_SMBUS_BLOCK_DATA;
 298
 299         if (vt596_features & FEATURE_I2CBLOCK)
 300                 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
 301         return func;
 302 }
 303
 304 static const struct i2c_algorithm smbus_algorithm = {
 305         .smbus_xfer     = vt596_access,
 306         .functionality  = vt596_func,
 307 };
 308
 309 static struct i2c_adapter vt596_adapter = {
 310         .owner          = THIS_MODULE,
 311         .id             = I2C_HW_SMBUS_VIA2,
 312         .class          = I2C_CLASS_HWMON,
 313         .algo           = &smbus_algorithm,
 314 };
 315
 316 static int __devinit vt596_probe(struct pci_dev *pdev,
 317                                  const struct pci_device_id *id)
 318 {
 319         unsigned char temp;
 320         int error = -ENODEV;
 321
 322         /* Determine the address of the SMBus areas */
 323         if (force_addr) {
 324                 vt596_smba = force_addr & 0xfff0;
 325                 force = 0;
 326                 goto found;
 327         }
 328
 329         if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
 330             !(vt596_smba & 0x0001)) {
 331                 /* try 2nd address and config reg. for 596 */
 332                 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
 333                     !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
 334                     (vt596_smba & 0x0001)) {
 335                         SMBHSTCFG = 0x84;
 336                 } else {
 337                         /* no matches at all */
 338                         dev_err(&pdev->dev, "Cannot configure "
 339                                 "SMBus I/O Base address\n");
 340                         return -ENODEV;
 341                 }
 342         }
 343
 344         vt596_smba &= 0xfff0;
 345         if (vt596_smba == 0) {
 346                 dev_err(&pdev->dev, "SMBus base address "
 347                         "uninitialized - upgrade BIOS or use "
 348                         "force_addr=0xaddr\n");
 349                 return -ENODEV;
 350         }
 351
 352 found:
 353         error = acpi_check_region(vt596_smba, 8, vt596_driver.name);
 354         if (error)
 355                 return error;
 356
 357         if (!request_region(vt596_smba, 8, vt596_driver.name)) {
 358                 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
 359                         vt596_smba);
 360                 return -ENODEV;
 361         }
 362
 363         pci_read_config_byte(pdev, SMBHSTCFG, &temp);
 364         /* If force_addr is set, we program the new address here. Just to make
 365            sure, we disable the VT596 first. */
 366         if (force_addr) {
 367                 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
 368                 pci_write_config_word(pdev, id->driver_data, vt596_smba);
 369                 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 370                 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
 371                          "address 0x%04x!\n", vt596_smba);
 372         } else if (!(temp & 0x01)) {
 373                 if (force) {
 374                         /* NOTE: This assumes I/O space and other allocations
 375                          * WERE done by the Bios!  Don't complain if your
 376                          * hardware does weird things after enabling this.
 377                          * :') Check for Bios updates before resorting to
 378                          * this.
 379                          */
 380                         pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 381                         dev_info(&pdev->dev, "Enabling SMBus device\n");
 382                 } else {
 383                         dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
 384                                 "controller not enabled! - upgrade BIOS or "
 385                                 "use force=1\n");
 386                         goto release_region;
 387                 }
 388         }
 389
 390         dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
 391
 392         switch (pdev->device) {
 393         case PCI_DEVICE_ID_VIA_CX700:
 394         case PCI_DEVICE_ID_VIA_8251:
 395         case PCI_DEVICE_ID_VIA_8237:
 396         case PCI_DEVICE_ID_VIA_8237A:
 397         case PCI_DEVICE_ID_VIA_8235:
 398         case PCI_DEVICE_ID_VIA_8233A:
 399         case PCI_DEVICE_ID_VIA_8233_0:
 400                 vt596_features |= FEATURE_I2CBLOCK;
 401                 break;
 402         case PCI_DEVICE_ID_VIA_82C686_4:
 403                 /* The VT82C686B (rev 0x40) does support I2C block
 404                    transactions, but the VT82C686A (rev 0x30) doesn't */
 405                 if (pdev->revision >= 0x40)
 406                         vt596_features |= FEATURE_I2CBLOCK;
 407                 break;
 408         }
 409
 410         vt596_adapter.dev.parent = &pdev->dev;
 411         snprintf(vt596_adapter.name, sizeof(vt596_adapter.name),
 412                  "SMBus Via Pro adapter at %04x", vt596_smba);
 413
 414         vt596_pdev = pci_dev_get(pdev);
 415         if (i2c_add_adapter(&vt596_adapter)) {
 416                 pci_dev_put(vt596_pdev);
 417                 vt596_pdev = NULL;
 418         }
 419
 420         /* Always return failure here.  This is to allow other drivers to bind
 421          * to this pci device.  We don't really want to have control over the
 422          * pci device, we only wanted to read as few register values from it.
 423          */
 424         return -ENODEV;
 425
 426 release_region:
 427         release_region(vt596_smba, 8);
 428         return error;
 429 }
 430
 431 static struct pci_device_id vt596_ids[] = {
 432         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
 433           .driver_data = SMBBA1 },
 434         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
 435           .driver_data = SMBBA1 },
 436         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
 437           .driver_data = SMBBA1 },
 438         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
 439           .driver_data = SMBBA3 },
 440         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
 441           .driver_data = SMBBA3 },
 442         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
 443           .driver_data = SMBBA3 },
 444         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
 445           .driver_data = SMBBA3 },
 446         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
 447           .driver_data = SMBBA3 },
 448         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
 449           .driver_data = SMBBA1 },
 450         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
 451           .driver_data = SMBBA3 },
 452         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
 453           .driver_data = SMBBA3 },
 454         { 0, }
 455 };
 456
 457 MODULE_DEVICE_TABLE(pci, vt596_ids);
 458
 459 static struct pci_driver vt596_driver = {
 460         .name           = "vt596_smbus",
 461         .id_table       = vt596_ids,
 462         .probe          = vt596_probe,
 463 };
 464
 465 static int __init i2c_vt596_init(void)
 466 {
 467         return pci_register_driver(&vt596_driver);
 468 }
 469
 470
 471 static void __exit i2c_vt596_exit(void)
 472 {
 473         pci_unregister_driver(&vt596_driver);
 474         if (vt596_pdev != NULL) {
 475                 i2c_del_adapter(&vt596_adapter);
 476                 release_region(vt596_smba, 8);
 477                 pci_dev_put(vt596_pdev);
 478                 vt596_pdev = NULL;
 479         }
 480 }
 481
 482 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
 483               "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
 484               "Jean Delvare <khali@linux-fr.org>");
 485 MODULE_DESCRIPTION("vt82c596 SMBus driver");
 486 MODULE_LICENSE("GPL");
 487
 488 module_init(i2c_vt596_init);
 489 module_exit(i2c_vt596_exit);