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
  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_PROC_CALL         0x10
  87 #define VT596_BLOCK_DATA        0x14
  88 #define VT596_I2C_BLOCK_DATA    0x34
  89
  90
  91 /* If force is set to anything different from 0, we forcibly enable the
  92    VT596. DANGEROUS! */
  93 static int force;
  94 module_param(force, bool, 0);
  95 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!");
  96
  97 /* If force_addr is set to anything different from 0, we forcibly enable
  98    the VT596 at the given address. VERY DANGEROUS! */
  99 static u16 force_addr;
 100 module_param(force_addr, ushort, 0);
 101 MODULE_PARM_DESC(force_addr,
 102                  "Forcibly enable the SMBus at the given address. "
 103                  "EXTREMELY DANGEROUS!");
 104
 105
 106 static struct pci_driver vt596_driver;
 107 static struct i2c_adapter vt596_adapter;
 108
 109 #define FEATURE_I2CBLOCK        (1<<0)
 110 static unsigned int vt596_features;
 111
 112 #ifdef DEBUG
 113 static void vt596_dump_regs(const char *msg, u8 size)
 114 {
 115         dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x "
 116                 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT),
 117                 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0),
 118                 inb_p(SMBHSTDAT1));
 119
 120         if (size == VT596_BLOCK_DATA
 121          || size == VT596_I2C_BLOCK_DATA) {
 122                 int i;
 123
 124                 dev_dbg(&vt596_adapter.dev, "BLK=");
 125                 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++)
 126                         printk("%02x,", inb_p(SMBBLKDAT));
 127                 printk("\n");
 128                 dev_dbg(&vt596_adapter.dev, "    ");
 129                 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++)
 130                         printk("%02x,", inb_p(SMBBLKDAT));
 131                 printk("%02x\n", inb_p(SMBBLKDAT));
 132         }
 133 }
 134 #else
 135 static inline void vt596_dump_regs(const char *msg, u8 size) { }
 136 #endif
 137
 138 /* Return -1 on error, 0 on success */
 139 static int vt596_transaction(u8 size)
 140 {
 141         int temp;
 142         int result = 0;
 143         int timeout = 0;
 144
 145         vt596_dump_regs("Transaction (pre)", size);
 146
 147         /* Make sure the SMBus host is ready to start transmitting */
 148         if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 149                 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
 150                         "Resetting...\n", temp);
 151
 152                 outb_p(temp, SMBHSTSTS);
 153                 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
 154                         dev_err(&vt596_adapter.dev, "SMBus reset failed! "
 155                                 "(0x%02x)\n", temp);
 156                         return -EBUSY;
 157                 }
 158         }
 159
 160         /* Start the transaction by setting bit 6 */
 161         outb_p(0x40 | size, SMBHSTCNT);
 162
 163         /* We will always wait for a fraction of a second */
 164         do {
 165                 msleep(1);
 166                 temp = inb_p(SMBHSTSTS);
 167         } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
 168
 169         /* If the SMBus is still busy, we give up */
 170         if (timeout >= MAX_TIMEOUT) {
 171                 result = -ETIMEDOUT;
 172                 dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
 173         }
 174
 175         if (temp & 0x10) {
 176                 result = -EIO;
 177                 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
 178                         size);
 179         }
 180
 181         if (temp & 0x08) {
 182                 result = -EIO;
 183                 dev_err(&vt596_adapter.dev, "SMBus collision!\n");
 184         }
 185
 186         if (temp & 0x04) {
 187                 int read = inb_p(SMBHSTADD) & 0x01;
 188                 result = -ENXIO;
 189                 /* The quick and receive byte commands are used to probe
 190                    for chips, so errors are expected, and we don't want
 191                    to frighten the user. */
 192                 if (!((size == VT596_QUICK && !read) ||
 193                       (size == VT596_BYTE && read)))
 194                         dev_err(&vt596_adapter.dev, "Transaction error!\n");
 195         }
 196
 197         /* Resetting status register */
 198         if (temp & 0x1F)
 199                 outb_p(temp, SMBHSTSTS);
 200
 201         vt596_dump_regs("Transaction (post)", size);
 202
 203         return result;
 204 }
 205
 206 /* Return negative errno on error, 0 on success */
 207 static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
 208                 unsigned short flags, char read_write, u8 command,
 209                 int size, union i2c_smbus_data *data)
 210 {
 211         int i;
 212         int status;
 213
 214         switch (size) {
 215         case I2C_SMBUS_QUICK:
 216                 size = VT596_QUICK;
 217                 break;
 218         case I2C_SMBUS_BYTE:
 219                 if (read_write == I2C_SMBUS_WRITE)
 220                         outb_p(command, SMBHSTCMD);
 221                 size = VT596_BYTE;
 222                 break;
 223         case I2C_SMBUS_BYTE_DATA:
 224                 outb_p(command, SMBHSTCMD);
 225                 if (read_write == I2C_SMBUS_WRITE)
 226                         outb_p(data->byte, SMBHSTDAT0);
 227                 size = VT596_BYTE_DATA;
 228                 break;
 229         case I2C_SMBUS_WORD_DATA:
 230                 outb_p(command, SMBHSTCMD);
 231                 if (read_write == I2C_SMBUS_WRITE) {
 232                         outb_p(data->word & 0xff, SMBHSTDAT0);
 233                         outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 234                 }
 235                 size = VT596_WORD_DATA;
 236                 break;
 237         case I2C_SMBUS_PROC_CALL:
 238                 outb_p(command, SMBHSTCMD);
 239                 outb_p(data->word & 0xff, SMBHSTDAT0);
 240                 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1);
 241                 size = VT596_PROC_CALL;
 242                 break;
 243         case I2C_SMBUS_I2C_BLOCK_DATA:
 244                 if (!(vt596_features & FEATURE_I2CBLOCK))
 245                         goto exit_unsupported;
 246                 if (read_write == I2C_SMBUS_READ)
 247                         outb_p(data->block[0], SMBHSTDAT0);
 248                 /* Fall through */
 249         case I2C_SMBUS_BLOCK_DATA:
 250                 outb_p(command, SMBHSTCMD);
 251                 if (read_write == I2C_SMBUS_WRITE) {
 252                         u8 len = data->block[0];
 253                         if (len > I2C_SMBUS_BLOCK_MAX)
 254                                 len = I2C_SMBUS_BLOCK_MAX;
 255                         outb_p(len, SMBHSTDAT0);
 256                         inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 257                         for (i = 1; i <= len; i++)
 258                                 outb_p(data->block[i], SMBBLKDAT);
 259                 }
 260                 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
 261                        VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
 262                 break;
 263         default:
 264                 goto exit_unsupported;
 265         }
 266
 267         outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
 268
 269         status = vt596_transaction(size);
 270         if (status)
 271                 return status;
 272
 273         if (size == VT596_PROC_CALL)
 274                 read_write = I2C_SMBUS_READ;
 275
 276         if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
 277                 return 0;
 278
 279         switch (size) {
 280         case VT596_BYTE:
 281         case VT596_BYTE_DATA:
 282                 data->byte = inb_p(SMBHSTDAT0);
 283                 break;
 284         case VT596_WORD_DATA:
 285         case VT596_PROC_CALL:
 286                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 287                 break;
 288         case VT596_I2C_BLOCK_DATA:
 289         case VT596_BLOCK_DATA:
 290                 data->block[0] = inb_p(SMBHSTDAT0);
 291                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 292                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 293                 inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 294                 for (i = 1; i <= data->block[0]; i++)
 295                         data->block[i] = inb_p(SMBBLKDAT);
 296                 break;
 297         }
 298         return 0;
 299
 300 exit_unsupported:
 301         dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n",
 302                  size);
 303         return -EOPNOTSUPP;
 304 }
 305
 306 static u32 vt596_func(struct i2c_adapter *adapter)
 307 {
 308         u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 309             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 310             I2C_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA;
 311
 312         if (vt596_features & FEATURE_I2CBLOCK)
 313                 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
 314         return func;
 315 }
 316
 317 static const struct i2c_algorithm smbus_algorithm = {
 318         .smbus_xfer     = vt596_access,
 319         .functionality  = vt596_func,
 320 };
 321
 322 static struct i2c_adapter vt596_adapter = {
 323         .owner          = THIS_MODULE,
 324         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 325         .algo           = &smbus_algorithm,
 326 };
 327
 328 static int __devinit vt596_probe(struct pci_dev *pdev,
 329                                  const struct pci_device_id *id)
 330 {
 331         unsigned char temp;
 332         int error = -ENODEV;
 333
 334         /* Determine the address of the SMBus areas */
 335         if (force_addr) {
 336                 vt596_smba = force_addr & 0xfff0;
 337                 force = 0;
 338                 goto found;
 339         }
 340
 341         if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
 342             !(vt596_smba & 0x0001)) {
 343                 /* try 2nd address and config reg. for 596 */
 344                 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
 345                     !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
 346                     (vt596_smba & 0x0001)) {
 347                         SMBHSTCFG = 0x84;
 348                 } else {
 349                         /* no matches at all */
 350                         dev_err(&pdev->dev, "Cannot configure "
 351                                 "SMBus I/O Base address\n");
 352                         return -ENODEV;
 353                 }
 354         }
 355
 356         vt596_smba &= 0xfff0;
 357         if (vt596_smba == 0) {
 358                 dev_err(&pdev->dev, "SMBus base address "
 359                         "uninitialized - upgrade BIOS or use "
 360                         "force_addr=0xaddr\n");
 361                 return -ENODEV;
 362         }
 363
 364 found:
 365         error = acpi_check_region(vt596_smba, 8, vt596_driver.name);
 366         if (error)
 367                 return error;
 368
 369         if (!request_region(vt596_smba, 8, vt596_driver.name)) {
 370                 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
 371                         vt596_smba);
 372                 return -ENODEV;
 373         }
 374
 375         pci_read_config_byte(pdev, SMBHSTCFG, &temp);
 376         /* If force_addr is set, we program the new address here. Just to make
 377            sure, we disable the VT596 first. */
 378         if (force_addr) {
 379                 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
 380                 pci_write_config_word(pdev, id->driver_data, vt596_smba);
 381                 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 382                 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
 383                          "address 0x%04x!\n", vt596_smba);
 384         } else if (!(temp & 0x01)) {
 385                 if (force) {
 386                         /* NOTE: This assumes I/O space and other allocations
 387                          * WERE done by the Bios!  Don't complain if your
 388                          * hardware does weird things after enabling this.
 389                          * :') Check for Bios updates before resorting to
 390                          * this.
 391                          */
 392                         pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 393                         dev_info(&pdev->dev, "Enabling SMBus device\n");
 394                 } else {
 395                         dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
 396                                 "controller not enabled! - upgrade BIOS or "
 397                                 "use force=1\n");
 398                         goto release_region;
 399                 }
 400         }
 401
 402         dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
 403
 404         switch (pdev->device) {
 405         case PCI_DEVICE_ID_VIA_CX700:
 406         case PCI_DEVICE_ID_VIA_VX800:
 407         case PCI_DEVICE_ID_VIA_8251:
 408         case PCI_DEVICE_ID_VIA_8237:
 409         case PCI_DEVICE_ID_VIA_8237A:
 410         case PCI_DEVICE_ID_VIA_8237S:
 411         case PCI_DEVICE_ID_VIA_8235:
 412         case PCI_DEVICE_ID_VIA_8233A:
 413         case PCI_DEVICE_ID_VIA_8233_0:
 414                 vt596_features |= FEATURE_I2CBLOCK;
 415                 break;
 416         case PCI_DEVICE_ID_VIA_82C686_4:
 417                 /* The VT82C686B (rev 0x40) does support I2C block
 418                    transactions, but the VT82C686A (rev 0x30) doesn't */
 419                 if (pdev->revision >= 0x40)
 420                         vt596_features |= FEATURE_I2CBLOCK;
 421                 break;
 422         }
 423
 424         vt596_adapter.dev.parent = &pdev->dev;
 425         snprintf(vt596_adapter.name, sizeof(vt596_adapter.name),
 426                  "SMBus Via Pro adapter at %04x", vt596_smba);
 427
 428         vt596_pdev = pci_dev_get(pdev);
 429         if (i2c_add_adapter(&vt596_adapter)) {
 430                 pci_dev_put(vt596_pdev);
 431                 vt596_pdev = NULL;
 432         }
 433
 434         /* Always return failure here.  This is to allow other drivers to bind
 435          * to this pci device.  We don't really want to have control over the
 436          * pci device, we only wanted to read as few register values from it.
 437          */
 438         return -ENODEV;
 439
 440 release_region:
 441         release_region(vt596_smba, 8);
 442         return error;
 443 }
 444
 445 static struct pci_device_id vt596_ids[] = {
 446         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
 447           .driver_data = SMBBA1 },
 448         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
 449           .driver_data = SMBBA1 },
 450         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
 451           .driver_data = SMBBA1 },
 452         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
 453           .driver_data = SMBBA3 },
 454         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
 455           .driver_data = SMBBA3 },
 456         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
 457           .driver_data = SMBBA3 },
 458         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
 459           .driver_data = SMBBA3 },
 460         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
 461           .driver_data = SMBBA3 },
 462         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S),
 463           .driver_data = SMBBA3 },
 464         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
 465           .driver_data = SMBBA1 },
 466         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
 467           .driver_data = SMBBA3 },
 468         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
 469           .driver_data = SMBBA3 },
 470         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800),
 471           .driver_data = SMBBA3 },
 472         { 0, }
 473 };
 474
 475 MODULE_DEVICE_TABLE(pci, vt596_ids);
 476
 477 static struct pci_driver vt596_driver = {
 478         .name           = "vt596_smbus",
 479         .id_table       = vt596_ids,
 480         .probe          = vt596_probe,
 481 };
 482
 483 static int __init i2c_vt596_init(void)
 484 {
 485         return pci_register_driver(&vt596_driver);
 486 }
 487
 488
 489 static void __exit i2c_vt596_exit(void)
 490 {
 491         pci_unregister_driver(&vt596_driver);
 492         if (vt596_pdev != NULL) {
 493                 i2c_del_adapter(&vt596_adapter);
 494                 release_region(vt596_smba, 8);
 495                 pci_dev_put(vt596_pdev);
 496                 vt596_pdev = NULL;
 497         }
 498 }
 499
 500 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
 501               "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
 502               "Jean Delvare <khali@linux-fr.org>");
 503 MODULE_DESCRIPTION("vt82c596 SMBus driver");
 504 MODULE_LICENSE("GPL");
 505
 506 module_init(i2c_vt596_init);
 507 module_exit(i2c_vt596_exit);