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 40 Note: we assume there can only be one device, with one SMBus interface. 41 */ 42 43 #include <linux/module.h> 44 #include <linux/delay.h> 45 #include <linux/pci.h> 46 #include <linux/kernel.h> 47 #include <linux/stddef.h> 48 #include <linux/ioport.h> 49 #include <linux/i2c.h> 50 #include <linux/init.h> 51 #include <linux/acpi.h> 52 #include <asm/io.h> 53 54 static struct pci_dev *vt596_pdev; 55 56 #define SMBBA1 0x90 57 #define SMBBA2 0x80 58 #define SMBBA3 0xD0 59 60 /* SMBus address offsets */ 61 static unsigned short vt596_smba; 62 #define SMBHSTSTS (vt596_smba + 0) 63 #define SMBHSTCNT (vt596_smba + 2) 64 #define SMBHSTCMD (vt596_smba + 3) 65 #define SMBHSTADD (vt596_smba + 4) 66 #define SMBHSTDAT0 (vt596_smba + 5) 67 #define SMBHSTDAT1 (vt596_smba + 6) 68 #define SMBBLKDAT (vt596_smba + 7) 69 70 /* PCI Address Constants */ 71 72 /* SMBus data in configuration space can be found in two places, 73 We try to select the better one */ 74 75 static unsigned short SMBHSTCFG = 0xD2; 76 77 /* Other settings */ 78 #define MAX_TIMEOUT 500 79 80 /* VT82C596 constants */ 81 #define VT596_QUICK 0x00 82 #define VT596_BYTE 0x04 83 #define VT596_BYTE_DATA 0x08 84 #define VT596_WORD_DATA 0x0C 85 #define VT596_BLOCK_DATA 0x14 86 #define VT596_I2C_BLOCK_DATA 0x34 87 88 89 /* If force is set to anything different from 0, we forcibly enable the 90 VT596. DANGEROUS! */ 91 static int force; 92 module_param(force, bool, 0); 93 MODULE_PARM_DESC(force, "Forcibly enable the SMBus. DANGEROUS!"); 94 95 /* If force_addr is set to anything different from 0, we forcibly enable 96 the VT596 at the given address. VERY DANGEROUS! */ 97 static u16 force_addr; 98 module_param(force_addr, ushort, 0); 99 MODULE_PARM_DESC(force_addr, 100 "Forcibly enable the SMBus at the given address. " 101 "EXTREMELY DANGEROUS!"); 102 103 104 static struct pci_driver vt596_driver; 105 static struct i2c_adapter vt596_adapter; 106 107 #define FEATURE_I2CBLOCK (1<<0) 108 static unsigned int vt596_features; 109 110 #ifdef DEBUG 111 static void vt596_dump_regs(const char *msg, u8 size) 112 { 113 dev_dbg(&vt596_adapter.dev, "%s: STS=%02x CNT=%02x CMD=%02x ADD=%02x " 114 "DAT=%02x,%02x\n", msg, inb_p(SMBHSTSTS), inb_p(SMBHSTCNT), 115 inb_p(SMBHSTCMD), inb_p(SMBHSTADD), inb_p(SMBHSTDAT0), 116 inb_p(SMBHSTDAT1)); 117 118 if (size == VT596_BLOCK_DATA 119 || size == VT596_I2C_BLOCK_DATA) { 120 int i; 121 122 dev_dbg(&vt596_adapter.dev, "BLK="); 123 for (i = 0; i < I2C_SMBUS_BLOCK_MAX / 2; i++) 124 printk("%02x,", inb_p(SMBBLKDAT)); 125 printk("\n"); 126 dev_dbg(&vt596_adapter.dev, " "); 127 for (; i < I2C_SMBUS_BLOCK_MAX - 1; i++) 128 printk("%02x,", inb_p(SMBBLKDAT)); 129 printk("%02x\n", inb_p(SMBBLKDAT)); 130 } 131 } 132 #else 133 static inline void vt596_dump_regs(const char *msg, u8 size) { } 134 #endif 135 136 /* Return -1 on error, 0 on success */ 137 static int vt596_transaction(u8 size) 138 { 139 int temp; 140 int result = 0; 141 int timeout = 0; 142 143 vt596_dump_regs("Transaction (pre)", size); 144 145 /* Make sure the SMBus host is ready to start transmitting */ 146 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) { 147 dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). " 148 "Resetting...\n", temp); 149 150 outb_p(temp, SMBHSTSTS); 151 if ((temp = inb_p(SMBHSTSTS)) & 0x1F) { 152 dev_err(&vt596_adapter.dev, "SMBus reset failed! " 153 "(0x%02x)\n", temp); 154 return -EBUSY; 155 } 156 } 157 158 /* Start the transaction by setting bit 6 */ 159 outb_p(0x40 | size, SMBHSTCNT); 160 161 /* We will always wait for a fraction of a second */ 162 do { 163 msleep(1); 164 temp = inb_p(SMBHSTSTS); 165 } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT)); 166 167 /* If the SMBus is still busy, we give up */ 168 if (timeout >= MAX_TIMEOUT) { 169 result = -ETIMEDOUT; 170 dev_err(&vt596_adapter.dev, "SMBus timeout!\n"); 171 } 172 173 if (temp & 0x10) { 174 result = -EIO; 175 dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n", 176 size); 177 } 178 179 if (temp & 0x08) { 180 result = -EIO; 181 dev_err(&vt596_adapter.dev, "SMBus collision!\n"); 182 } 183 184 if (temp & 0x04) { 185 int read = inb_p(SMBHSTADD) & 0x01; 186 result = -ENXIO; 187 /* The quick and receive byte commands are used to probe 188 for chips, so errors are expected, and we don't want 189 to frighten the user. */ 190 if (!((size == VT596_QUICK && !read) || 191 (size == VT596_BYTE && read))) 192 dev_err(&vt596_adapter.dev, "Transaction error!\n"); 193 } 194 195 /* Resetting status register */ 196 if (temp & 0x1F) 197 outb_p(temp, SMBHSTSTS); 198 199 vt596_dump_regs("Transaction (post)", size); 200 201 return result; 202 } 203 204 /* Return negative errno on error, 0 on success */ 205 static s32 vt596_access(struct i2c_adapter *adap, u16 addr, 206 unsigned short flags, char read_write, u8 command, 207 int size, union i2c_smbus_data *data) 208 { 209 int i; 210 int status; 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 status = vt596_transaction(size); 262 if (status) 263 return status; 264 265 if ((read_write == I2C_SMBUS_WRITE) || (size == VT596_QUICK)) 266 return 0; 267 268 switch (size) { 269 case VT596_BYTE: 270 case VT596_BYTE_DATA: 271 data->byte = inb_p(SMBHSTDAT0); 272 break; 273 case VT596_WORD_DATA: 274 data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8); 275 break; 276 case VT596_I2C_BLOCK_DATA: 277 case VT596_BLOCK_DATA: 278 data->block[0] = inb_p(SMBHSTDAT0); 279 if (data->block[0] > I2C_SMBUS_BLOCK_MAX) 280 data->block[0] = I2C_SMBUS_BLOCK_MAX; 281 inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */ 282 for (i = 1; i <= data->block[0]; i++) 283 data->block[i] = inb_p(SMBBLKDAT); 284 break; 285 } 286 return 0; 287 288 exit_unsupported: 289 dev_warn(&vt596_adapter.dev, "Unsupported transaction %d\n", 290 size); 291 return -EOPNOTSUPP; 292 } 293 294 static u32 vt596_func(struct i2c_adapter *adapter) 295 { 296 u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 297 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 298 I2C_FUNC_SMBUS_BLOCK_DATA; 299 300 if (vt596_features & FEATURE_I2CBLOCK) 301 func |= I2C_FUNC_SMBUS_I2C_BLOCK; 302 return func; 303 } 304 305 static const struct i2c_algorithm smbus_algorithm = { 306 .smbus_xfer = vt596_access, 307 .functionality = vt596_func, 308 }; 309 310 static struct i2c_adapter vt596_adapter = { 311 .owner = THIS_MODULE, 312 .id = I2C_HW_SMBUS_VIA2, 313 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, 314 .algo = &smbus_algorithm, 315 }; 316 317 static int __devinit vt596_probe(struct pci_dev *pdev, 318 const struct pci_device_id *id) 319 { 320 unsigned char temp; 321 int error = -ENODEV; 322 323 /* driver_data might come from user-space, so check it */ 324 if (id->driver_data & 1 || id->driver_data > 0xff) 325 return -EINVAL; 326 327 /* Determine the address of the SMBus areas */ 328 if (force_addr) { 329 vt596_smba = force_addr & 0xfff0; 330 force = 0; 331 goto found; 332 } 333 334 if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) || 335 !(vt596_smba & 0x0001)) { 336 /* try 2nd address and config reg. for 596 */ 337 if (id->device == PCI_DEVICE_ID_VIA_82C596_3 && 338 !pci_read_config_word(pdev, SMBBA2, &vt596_smba) && 339 (vt596_smba & 0x0001)) { 340 SMBHSTCFG = 0x84; 341 } else { 342 /* no matches at all */ 343 dev_err(&pdev->dev, "Cannot configure " 344 "SMBus I/O Base address\n"); 345 return -ENODEV; 346 } 347 } 348 349 vt596_smba &= 0xfff0; 350 if (vt596_smba == 0) { 351 dev_err(&pdev->dev, "SMBus base address " 352 "uninitialized - upgrade BIOS or use " 353 "force_addr=0xaddr\n"); 354 return -ENODEV; 355 } 356 357 found: 358 error = acpi_check_region(vt596_smba, 8, vt596_driver.name); 359 if (error) 360 return error; 361 362 if (!request_region(vt596_smba, 8, vt596_driver.name)) { 363 dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n", 364 vt596_smba); 365 return -ENODEV; 366 } 367 368 pci_read_config_byte(pdev, SMBHSTCFG, &temp); 369 /* If force_addr is set, we program the new address here. Just to make 370 sure, we disable the VT596 first. */ 371 if (force_addr) { 372 pci_write_config_byte(pdev, SMBHSTCFG, temp & 0xfe); 373 pci_write_config_word(pdev, id->driver_data, vt596_smba); 374 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01); 375 dev_warn(&pdev->dev, "WARNING: SMBus interface set to new " 376 "address 0x%04x!\n", vt596_smba); 377 } else if (!(temp & 0x01)) { 378 if (force) { 379 /* NOTE: This assumes I/O space and other allocations 380 * WERE done by the Bios! Don't complain if your 381 * hardware does weird things after enabling this. 382 * :') Check for Bios updates before resorting to 383 * this. 384 */ 385 pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01); 386 dev_info(&pdev->dev, "Enabling SMBus device\n"); 387 } else { 388 dev_err(&pdev->dev, "SMBUS: Error: Host SMBus " 389 "controller not enabled! - upgrade BIOS or " 390 "use force=1\n"); 391 goto release_region; 392 } 393 } 394 395 dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba); 396 397 switch (pdev->device) { 398 case PCI_DEVICE_ID_VIA_CX700: 399 case PCI_DEVICE_ID_VIA_8251: 400 case PCI_DEVICE_ID_VIA_8237: 401 case PCI_DEVICE_ID_VIA_8237A: 402 case PCI_DEVICE_ID_VIA_8237S: 403 case PCI_DEVICE_ID_VIA_8235: 404 case PCI_DEVICE_ID_VIA_8233A: 405 case PCI_DEVICE_ID_VIA_8233_0: 406 vt596_features |= FEATURE_I2CBLOCK; 407 break; 408 case PCI_DEVICE_ID_VIA_82C686_4: 409 /* The VT82C686B (rev 0x40) does support I2C block 410 transactions, but the VT82C686A (rev 0x30) doesn't */ 411 if (pdev->revision >= 0x40) 412 vt596_features |= FEATURE_I2CBLOCK; 413 break; 414 } 415 416 vt596_adapter.dev.parent = &pdev->dev; 417 snprintf(vt596_adapter.name, sizeof(vt596_adapter.name), 418 "SMBus Via Pro adapter at %04x", vt596_smba); 419 420 vt596_pdev = pci_dev_get(pdev); 421 if (i2c_add_adapter(&vt596_adapter)) { 422 pci_dev_put(vt596_pdev); 423 vt596_pdev = NULL; 424 } 425 426 /* Always return failure here. This is to allow other drivers to bind 427 * to this pci device. We don't really want to have control over the 428 * pci device, we only wanted to read as few register values from it. 429 */ 430 return -ENODEV; 431 432 release_region: 433 release_region(vt596_smba, 8); 434 return error; 435 } 436 437 static struct pci_device_id vt596_ids[] = { 438 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596_3), 439 .driver_data = SMBBA1 }, 440 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C596B_3), 441 .driver_data = SMBBA1 }, 442 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4), 443 .driver_data = SMBBA1 }, 444 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_0), 445 .driver_data = SMBBA3 }, 446 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233A), 447 .driver_data = SMBBA3 }, 448 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235), 449 .driver_data = SMBBA3 }, 450 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237), 451 .driver_data = SMBBA3 }, 452 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237A), 453 .driver_data = SMBBA3 }, 454 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237S), 455 .driver_data = SMBBA3 }, 456 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4), 457 .driver_data = SMBBA1 }, 458 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8251), 459 .driver_data = SMBBA3 }, 460 { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700), 461 .driver_data = SMBBA3 }, 462 { 0, } 463 }; 464 465 MODULE_DEVICE_TABLE(pci, vt596_ids); 466 467 static struct pci_driver vt596_driver = { 468 .name = "vt596_smbus", 469 .id_table = vt596_ids, 470 .probe = vt596_probe, 471 .dynids.use_driver_data = 1, 472 }; 473 474 static int __init i2c_vt596_init(void) 475 { 476 return pci_register_driver(&vt596_driver); 477 } 478 479 480 static void __exit i2c_vt596_exit(void) 481 { 482 pci_unregister_driver(&vt596_driver); 483 if (vt596_pdev != NULL) { 484 i2c_del_adapter(&vt596_adapter); 485 release_region(vt596_smba, 8); 486 pci_dev_put(vt596_pdev); 487 vt596_pdev = NULL; 488 } 489 } 490 491 MODULE_AUTHOR("Kyosti Malkki <kmalkki@cc.hut.fi>, " 492 "Mark D. Studebaker <mdsxyz123@yahoo.com> and " 493 "Jean Delvare <khali@linux-fr.org>"); 494 MODULE_DESCRIPTION("vt82c596 SMBus driver"); 495 MODULE_LICENSE("GPL"); 496 497 module_init(i2c_vt596_init); 498 module_exit(i2c_vt596_exit); 499