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 - 2008  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    VT8237S            0x3372             yes
  39    VT8251             0x3287             yes
  40    CX700              0x8324             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_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_I2C_BLOCK_DATA:
 238                 if (!(vt596_features & FEATURE_I2CBLOCK))
 239                         goto exit_unsupported;
 240                 if (read_write == I2C_SMBUS_READ)
 241                         outb_p(data->block[0], SMBHSTDAT0);
 242                 /* Fall through */
 243         case I2C_SMBUS_BLOCK_DATA:
 244                 outb_p(command, SMBHSTCMD);
 245                 if (read_write == I2C_SMBUS_WRITE) {
 246                         u8 len = data->block[0];
 247                         if (len > I2C_SMBUS_BLOCK_MAX)
 248                                 len = I2C_SMBUS_BLOCK_MAX;
 249                         outb_p(len, SMBHSTDAT0);
 250                         inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 251                         for (i = 1; i <= len; i++)
 252                                 outb_p(data->block[i], SMBBLKDAT);
 253                 }
 254                 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
 255                        VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
 256                 break;
 257         default:
 258                 goto exit_unsupported;
 259         }
 260
 261         outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
 262
 263         status = vt596_transaction(size);
 264         if (status)
 265                 return status;
 266
 267         if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK))
 268                 return 0;
 269
 270         switch (size) {
 271         case VT596_BYTE:
 272         case VT596_BYTE_DATA:
 273                 data->byte = inb_p(SMBHSTDAT0);
 274                 break;
 275         case VT596_WORD_DATA:
 276                 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
 277                 break;
 278         case VT596_I2C_BLOCK_DATA:
 279         case VT596_BLOCK_DATA:
 280                 data->block[0] = inb_p(SMBHSTDAT0);
 281                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 282                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 283                 inb_p(SMBHSTCNT);       /* Reset SMBBLKDAT */
 284                 for (i = 1; i <= data->block[0]; i++)
 285                         data->block[i] = inb_p(SMBBLKDAT);
 286                 break;
 287         }
 288         return 0;
 289
 290 exit_unsupported:
 291         dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n",
 292                  size);
 293         return -EOPNOTSUPP;
 294 }
 295
 296 static u32 vt596_func(struct i2c_adapter *adapter)
 297 {
 298         u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 299             I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 300             I2C_FUNC_SMBUS_BLOCK_DATA;
 301
 302         if (vt596_features & FEATURE_I2CBLOCK)
 303                 func |= I2C_FUNC_SMBUS_I2C_BLOCK;
 304         return func;
 305 }
 306
 307 static const struct i2c_algorithm smbus_algorithm = {
 308         .smbus_xfer     = vt596_access,
 309         .functionality  = vt596_func,
 310 };
 311
 312 static struct i2c_adapter vt596_adapter = {
 313         .owner          = THIS_MODULE,
 314         .id             = I2C_HW_SMBUS_VIA2,
 315         .class          = I2C_CLASS_HWMON | I2C_CLASS_SPD,
 316         .algo           = &smbus_algorithm,
 317 };
 318
 319 static int __devinit vt596_probe(struct pci_dev *pdev,
 320                                  const struct pci_device_id *id)
 321 {
 322         unsigned char temp;
 323         int error = -ENODEV;
 324
 325         /* driver_data might come from user-space, so check it */
 326         if (id->driver_data & 1 || id->driver_data > 0xff)
 327                 return -EINVAL;
 328
 329         /* Determine the address of the SMBus areas */
 330         if (force_addr) {
 331                 vt596_smba = force_addr & 0xfff0;
 332                 force = 0;
 333                 goto found;
 334         }
 335
 336         if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
 337             !(vt596_smba & 0x0001)) {
 338                 /* try 2nd address and config reg. for 596 */
 339                 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
 340                     !pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
 341                     (vt596_smba & 0x0001)) {
 342                         SMBHSTCFG = 0x84;
 343                 } else {
 344                         /* no matches at all */
 345                         dev_err(&pdev->dev, "Cannot configure "
 346                                 "SMBus I/O Base address\n");
 347                         return -ENODEV;
 348                 }
 349         }
 350
 351         vt596_smba &= 0xfff0;
 352         if (vt596_smba == 0) {
 353                 dev_err(&pdev->dev, "SMBus base address "
 354                         "uninitialized - upgrade BIOS or use "
 355                         "force_addr=0xaddr\n");
 356                 return -ENODEV;
 357         }
 358
 359 found:
 360         error = acpi_check_region(vt596_smba, 8, vt596_driver.name);
 361         if (error)
 362                 return error;
 363
 364         if (!request_region(vt596_smba, 8, vt596_driver.name)) {
 365                 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
 366                         vt596_smba);
 367                 return -ENODEV;
 368         }
 369
 370         pci_read_config_byte(pdev, SMBHSTCFG, &temp);
 371         /* If force_addr is set, we program the new address here. Just to make
 372            sure, we disable the VT596 first. */
 373         if (force_addr) {
 374                 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe);
 375                 pci_write_config_word(pdev, id->driver_data, vt596_smba);
 376                 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 377                 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
 378                          "address 0x%04x!\n", vt596_smba);
 379         } else if (!(temp & 0x01)) {
 380                 if (force) {
 381                         /* NOTE: This assumes I/O space and other allocations
 382                          * WERE done by the Bios!  Don't complain if your
 383                          * hardware does weird things after enabling this.
 384                          * :') Check for Bios updates before resorting to
 385                          * this.
 386                          */
 387                         pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
 388                         dev_info(&pdev->dev, "Enabling SMBus device\n");
 389                 } else {
 390                         dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
 391                                 "controller not enabled! - upgrade BIOS or "
 392                                 "use force=1\n");
 393                         goto release_region;
 394                 }
 395         }
 396
 397         dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
 398
 399         switch (pdev->device) {
 400         case PCI_DEVICE_ID_VIA_CX700:
 401         case PCI_DEVICE_ID_VIA_8251:
 402         case PCI_DEVICE_ID_VIA_8237:
 403         case PCI_DEVICE_ID_VIA_8237A:
 404         case PCI_DEVICE_ID_VIA_8237S:
 405         case PCI_DEVICE_ID_VIA_8235:
 406         case PCI_DEVICE_ID_VIA_8233A:
 407         case PCI_DEVICE_ID_VIA_8233_0:
 408                 vt596_features |= FEATURE_I2CBLOCK;
 409                 break;
 410         case PCI_DEVICE_ID_VIA_82C686_4:
 411                 /* The VT82C686B (rev 0x40) does support I2C block
 412                    transactions, but the VT82C686A (rev 0x30) doesn't */
 413                 if (pdev->revision >= 0x40)
 414                         vt596_features |= FEATURE_I2CBLOCK;
 415                 break;
 416         }
 417
 418         vt596_adapter.dev.parent = &pdev->dev;
 419         snprintf(vt596_adapter.name, sizeof(vt596_adapter.name),
 420                  "SMBus Via Pro adapter at %04x", vt596_smba);
 421
 422         vt596_pdev = pci_dev_get(pdev);
 423         if (i2c_add_adapter(&vt596_adapter)) {
 424                 pci_dev_put(vt596_pdev);
 425                 vt596_pdev = NULL;
 426         }
 427
 428         /* Always return failure here.  This is to allow other drivers to bind
 429          * to this pci device.  We don't really want to have control over the
 430          * pci device, we only wanted to read as few register values from it.
 431          */
 432         return -ENODEV;
 433
 434 release_region:
 435         release_region(vt596_smba, 8);
 436         return error;
 437 }
 438
 439 static struct pci_device_id vt596_ids[] = {
 440         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3),
 441           .driver_data = SMBBA1 },
 442         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3),
 443           .driver_data = SMBBA1 },
 444         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4),
 445           .driver_data = SMBBA1 },
 446         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0),
 447           .driver_data = SMBBA3 },
 448         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A),
 449           .driver_data = SMBBA3 },
 450         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235),
 451           .driver_data = SMBBA3 },
 452         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237),
 453           .driver_data = SMBBA3 },
 454         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A),
 455           .driver_data = SMBBA3 },
 456         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S),
 457           .driver_data = SMBBA3 },
 458         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4),
 459           .driver_data = SMBBA1 },
 460         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251),
 461           .driver_data = SMBBA3 },
 462         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700),
 463           .driver_data = SMBBA3 },
 464         { 0, }
 465 };
 466
 467 MODULE_DEVICE_TABLE(pci, vt596_ids);
 468
 469 static struct pci_driver vt596_driver = {
 470         .name           = "vt596_smbus",
 471         .id_table       = vt596_ids,
 472         .probe          = vt596_probe,
 473         .dynids.use_driver_data = 1,
 474 };
 475
 476 static int __init i2c_vt596_init(void)
 477 {
 478         return pci_register_driver(&vt596_driver);
 479 }
 480
 481
 482 static void __exit i2c_vt596_exit(void)
 483 {
 484         pci_unregister_driver(&vt596_driver);
 485         if (vt596_pdev != NULL) {
 486                 i2c_del_adapter(&vt596_adapter);
 487                 release_region(vt596_smba, 8);
 488                 pci_dev_put(vt596_pdev);
 489                 vt596_pdev = NULL;
 490         }
 491 }
 492
 493 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, "
 494               "Mark D. Studebaker <mdsxyz123@yahoo.com> and "
 495               "Jean Delvare <khali@linux-fr.org>");
 496 MODULE_DESCRIPTION("vt82c596 SMBus driver");
 497 MODULE_LICENSE("GPL");
 498
 499 module_init(i2c_vt596_init);
 500 module_exit(i2c_vt596_exit);