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 <jdelvare@suse.de> 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 VX855/VX875 0x8409 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 <linux/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_PROC_CALL 0x10 88 #define VT596_BLOCK_DATA 0x14 89 #define VT596_I2C_BLOCK_DATA 0x34 90 91 92 /* If force is set to anything different from 0, we forcibly enable the 93 VT596. DANGEROUS! */ 94 static bool force; 95 module_param(force, bool, 0); 96 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!"); 97 98 /* If force_addr is set to anything different from 0, we forcibly enable 99 the VT596 at the given address. VERY DANGEROUS! */ 100 static u16 force_addr; 101 module_param(force_addr, ushort, 0); 102 MODULE_PARM_DESC(force_addr, 103 "Forcibly enable the SMBus at the given address. " 104 "EXTREMELY DANGEROUS!"); 105 106 107 static struct pci_driver vt596_driver; 108 static struct i2c_adapter vt596_adapter; 109 110 #define FEATURE_I2CBLOCK (1<<0) 111 static unsigned int vt596_features; 112 113 #ifdef DEBUG 114 static void vt596_dump_regs(const char *msg, u8 size) 115 { 116 dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x " 117 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT), 118 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), 119 inb_p(SMBHSTDAT1)); 120 121 if (size == VT596_BLOCK_DATA 122 || size == VT596_I2C_BLOCK_DATA) { 123 int i; 124 125 dev_dbg(&vt596_adapter.dev, "BLK="); 126 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++) 127 printk("%02x,", inb_p(SMBBLKDAT)); 128 printk("\n"); 129 dev_dbg(&vt596_adapter.dev, " "); 130 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++) 131 printk("%02x,", inb_p(SMBBLKDAT)); 132 printk("%02x\n", inb_p(SMBBLKDAT)); 133 } 134 } 135 #else 136 static inline void vt596_dump_regs(const char *msg, u8 size) { } 137 #endif 138 139 /* Return -1 on error, 0 on success */ 140 static int vt596_transaction(u8 size) 141 { 142 int temp; 143 int result = 0; 144 int timeout = 0; 145 146 vt596_dump_regs("Transaction (pre)", size); 147 148 /* Make sure the SMBus host is ready to start transmitting */ 149 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) { 150 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). " 151 "Resetting...\n", temp); 152 153 outb_p(temp, SMBHSTSTS); 154 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) { 155 dev_err(&vt596_adapter.dev, "SMBus reset failed! " 156 "(0x%02x)\n", temp); 157 return -EBUSY; 158 } 159 } 160 161 /* Start the transaction by setting bit 6 */ 162 outb_p(0x40 | size, SMBHSTCNT); 163 164 /* We will always wait for a fraction of a second */ 165 do { 166 msleep(1); 167 temp = inb_p(SMBHSTSTS); 168 } while ((temp & 0x01) && (++timeout < MAX_TIMEOUT)); 169 170 /* If the SMBus is still busy, we give up */ 171 if (timeout == MAX_TIMEOUT) { 172 result = -ETIMEDOUT; 173 dev_err(&vt596_adapter.dev, "SMBus timeout!\n"); 174 } 175 176 if (temp & 0x10) { 177 result = -EIO; 178 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n", 179 size); 180 } 181 182 if (temp & 0x08) { 183 result = -EIO; 184 dev_err(&vt596_adapter.dev, "SMBus collision!\n"); 185 } 186 187 if (temp & 0x04) { 188 result = -ENXIO; 189 dev_dbg(&vt596_adapter.dev, "No response\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 negative errno 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 int status; 208 209 switch (size) { 210 case I2C_SMBUS_QUICK: 211 size = VT596_QUICK; 212 break; 213 case I2C_SMBUS_BYTE: 214 if (read_write == I2C_SMBUS_WRITE) 215 outb_p(command, SMBHSTCMD); 216 size = VT596_BYTE; 217 break; 218 case I2C_SMBUS_BYTE_DATA: 219 outb_p(command, SMBHSTCMD); 220 if (read_write == I2C_SMBUS_WRITE) 221 outb_p(data->byte, SMBHSTDAT0); 222 size = VT596_BYTE_DATA; 223 break; 224 case I2C_SMBUS_WORD_DATA: 225 outb_p(command, SMBHSTCMD); 226 if (read_write == I2C_SMBUS_WRITE) { 227 outb_p(data->word & 0xff, SMBHSTDAT0); 228 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1); 229 } 230 size = VT596_WORD_DATA; 231 break; 232 case I2C_SMBUS_PROC_CALL: 233 outb_p(command, SMBHSTCMD); 234 outb_p(data->word & 0xff, SMBHSTDAT0); 235 outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1); 236 size = VT596_PROC_CALL; 237 break; 238 case I2C_SMBUS_I2C_BLOCK_DATA: 239 if (!(vt596_features & FEATURE_I2CBLOCK)) 240 goto exit_unsupported; 241 if (read_write == I2C_SMBUS_READ) 242 outb_p(data->block[0], SMBHSTDAT0); 243 /* Fall through */ 244 case I2C_SMBUS_BLOCK_DATA: 245 outb_p(command, SMBHSTCMD); 246 if (read_write == I2C_SMBUS_WRITE) { 247 u8 len = data->block[0]; 248 if (len > I2C_SMBUS_BLOCK_MAX) 249 len = I2C_SMBUS_BLOCK_MAX; 250 outb_p(len, SMBHSTDAT0); 251 inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */ 252 for (i = 1; i <= len; i++) 253 outb_p(data->block[i], SMBBLKDAT); 254 } 255 size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ? 256 VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA; 257 break; 258 default: 259 goto exit_unsupported; 260 } 261 262 outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD); 263 264 status = vt596_transaction(size); 265 if (status) 266 return status; 267 268 if (size == VT596_PROC_CALL) 269 read_write = I2C_SMBUS_READ; 270 271 if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK)) 272 return 0; 273 274 switch (size) { 275 case VT596_BYTE: 276 case VT596_BYTE_DATA: 277 data->byte = inb_p(SMBHSTDAT0); 278 break; 279 case VT596_WORD_DATA: 280 case VT596_PROC_CALL: 281 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8); 282 break; 283 case VT596_I2C_BLOCK_DATA: 284 case VT596_BLOCK_DATA: 285 data->block[0] = inb_p(SMBHSTDAT0); 286 if (data->block[0] > I2C_SMBUS_BLOCK_MAX) 287 data->block[0] = I2C_SMBUS_BLOCK_MAX; 288 inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */ 289 for (i = 1; i <= data->block[0]; i++) 290 data->block[i] = inb_p(SMBBLKDAT); 291 break; 292 } 293 return 0; 294 295 exit_unsupported: 296 dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n", 297 size); 298 return -EOPNOTSUPP; 299 } 300 301 static u32 vt596_func(struct i2c_adapter *adapter) 302 { 303 u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 304 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 305 I2C_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA; 306 307 if (vt596_features & FEATURE_I2CBLOCK) 308 func |= I2C_FUNC_SMBUS_I2C_BLOCK; 309 return func; 310 } 311 312 static const struct i2c_algorithm smbus_algorithm = { 313 .smbus_xfer = vt596_access, 314 .functionality = vt596_func, 315 }; 316 317 static struct i2c_adapter vt596_adapter = { 318 .owner = THIS_MODULE, 319 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, 320 .algo = &smbus_algorithm, 321 }; 322 323 static int vt596_probe(struct pci_dev *pdev, 324 const struct pci_device_id *id) 325 { 326 unsigned char temp; 327 int error; 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 -ENODEV; 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 error = -ENODEV; 394 goto release_region; 395 } 396 } 397 398 dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba); 399 400 switch (pdev->device) { 401 case PCI_DEVICE_ID_VIA_CX700: 402 case PCI_DEVICE_ID_VIA_VX800: 403 case PCI_DEVICE_ID_VIA_VX855: 404 case PCI_DEVICE_ID_VIA_VX900: 405 case PCI_DEVICE_ID_VIA_8251: 406 case PCI_DEVICE_ID_VIA_8237: 407 case PCI_DEVICE_ID_VIA_8237A: 408 case PCI_DEVICE_ID_VIA_8237S: 409 case PCI_DEVICE_ID_VIA_8235: 410 case PCI_DEVICE_ID_VIA_8233A: 411 case PCI_DEVICE_ID_VIA_8233_0: 412 vt596_features |= FEATURE_I2CBLOCK; 413 break; 414 case PCI_DEVICE_ID_VIA_82C686_4: 415 /* The VT82C686B (rev 0x40) does support I2C block 416 transactions, but the VT82C686A (rev 0x30) doesn't */ 417 if (pdev->revision >= 0x40) 418 vt596_features |= FEATURE_I2CBLOCK; 419 break; 420 } 421 422 vt596_adapter.dev.parent = &pdev->dev; 423 snprintf(vt596_adapter.name, sizeof(vt596_adapter.name), 424 "SMBus Via Pro adapter at %04x", vt596_smba); 425 426 vt596_pdev = pci_dev_get(pdev); 427 error = i2c_add_adapter(&vt596_adapter); 428 if (error) { 429 pci_dev_put(vt596_pdev); 430 vt596_pdev = NULL; 431 goto release_region; 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 DEFINE_PCI_DEVICE_TABLE(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 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855), 473 .driver_data = SMBBA3 }, 474 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX900), 475 .driver_data = SMBBA3 }, 476 { 0, } 477 }; 478 479 MODULE_DEVICE_TABLE(pci, vt596_ids); 480 481 static struct pci_driver vt596_driver = { 482 .name = "vt596_smbus", 483 .id_table = vt596_ids, 484 .probe = vt596_probe, 485 }; 486 487 static int __init i2c_vt596_init(void) 488 { 489 return pci_register_driver(&vt596_driver); 490 } 491 492 493 static void __exit i2c_vt596_exit(void) 494 { 495 pci_unregister_driver(&vt596_driver); 496 if (vt596_pdev != NULL) { 497 i2c_del_adapter(&vt596_adapter); 498 release_region(vt596_smba, 8); 499 pci_dev_put(vt596_pdev); 500 vt596_pdev = NULL; 501 } 502 } 503 504 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, " 505 "Mark D. Studebaker <mdsxyz123@yahoo.com> and " 506 "Jean Delvare <jdelvare@suse.de>"); 507 MODULE_DESCRIPTION("vt82c596 SMBus driver"); 508 MODULE_LICENSE("GPL"); 509 510 module_init(i2c_vt596_init); 511 module_exit(i2c_vt596_exit); 512