1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 Copyright (c) 2002,2003 Alexander Malysh <amalysh@web.de> 4 5 */ 6 7 /* 8 Status: beta 9 10 Supports: 11 SIS 630 12 SIS 730 13 SIS 964 14 15 Notable differences between chips: 16 +------------------------+--------------------+-------------------+ 17 | | SIS630/730 | SIS964 | 18 +------------------------+--------------------+-------------------+ 19 | Clock | 14kHz/56kHz | 55.56kHz/27.78kHz | 20 | SMBus registers offset | 0x80 | 0xE0 | 21 | SMB_CNT | Bit 1 = Slave Busy | Bit 1 = Bus probe | 22 | (not used yet) | Bit 3 is reserved | Bit 3 = Last byte | 23 | SMB_PCOUNT | Offset + 0x06 | Offset + 0x14 | 24 | SMB_COUNT | 4:0 bits | 5:0 bits | 25 +------------------------+--------------------+-------------------+ 26 (Other differences don't affect the functions provided by the driver) 27 28 Note: we assume there can only be one device, with one SMBus interface. 29 */ 30 31 #include <linux/kernel.h> 32 #include <linux/module.h> 33 #include <linux/delay.h> 34 #include <linux/pci.h> 35 #include <linux/ioport.h> 36 #include <linux/i2c.h> 37 #include <linux/acpi.h> 38 #include <linux/io.h> 39 40 /* SIS964 id is defined here as we are the only file using it */ 41 #define PCI_DEVICE_ID_SI_964 0x0964 42 43 /* SIS630/730/964 SMBus registers */ 44 #define SMB_STS 0x00 /* status */ 45 #define SMB_CNT 0x02 /* control */ 46 #define SMBHOST_CNT 0x03 /* host control */ 47 #define SMB_ADDR 0x04 /* address */ 48 #define SMB_CMD 0x05 /* command */ 49 #define SMB_COUNT 0x07 /* byte count */ 50 #define SMB_BYTE 0x08 /* ~0x8F data byte field */ 51 52 /* SMB_STS register */ 53 #define BYTE_DONE_STS 0x10 /* Byte Done Status / Block Array */ 54 #define SMBCOL_STS 0x04 /* Collision */ 55 #define SMBERR_STS 0x02 /* Device error */ 56 57 /* SMB_CNT register */ 58 #define MSTO_EN 0x40 /* Host Master Timeout Enable */ 59 #define SMBCLK_SEL 0x20 /* Host master clock selection */ 60 #define SMB_PROBE 0x02 /* Bus Probe/Slave busy */ 61 #define SMB_HOSTBUSY 0x01 /* Host Busy */ 62 63 /* SMBHOST_CNT register */ 64 #define SMB_KILL 0x20 /* Kill */ 65 #define SMB_START 0x10 /* Start */ 66 67 /* register count for request_region 68 * As we don't use SMB_PCOUNT, 20 is ok for SiS630 and SiS964 69 */ 70 #define SIS630_SMB_IOREGION 20 71 72 /* PCI address constants */ 73 /* acpi base address register */ 74 #define SIS630_ACPI_BASE_REG 0x74 75 /* bios control register */ 76 #define SIS630_BIOS_CTL_REG 0x40 77 78 /* Other settings */ 79 #define MAX_TIMEOUT 500 80 81 /* SIS630 constants */ 82 #define SIS630_QUICK 0x00 83 #define SIS630_BYTE 0x01 84 #define SIS630_BYTE_DATA 0x02 85 #define SIS630_WORD_DATA 0x03 86 #define SIS630_PCALL 0x04 87 #define SIS630_BLOCK_DATA 0x05 88 89 static struct pci_driver sis630_driver; 90 91 /* insmod parameters */ 92 static bool high_clock; 93 static bool force; 94 module_param(high_clock, bool, 0); 95 MODULE_PARM_DESC(high_clock, 96 "Set Host Master Clock to 56KHz (default 14KHz) (SIS630/730 only)."); 97 module_param(force, bool, 0); 98 MODULE_PARM_DESC(force, "Forcibly enable the SIS630. DANGEROUS!"); 99 100 /* SMBus base address */ 101 static unsigned short smbus_base; 102 103 /* supported chips */ 104 static int supported[] = { 105 PCI_DEVICE_ID_SI_630, 106 PCI_DEVICE_ID_SI_730, 107 PCI_DEVICE_ID_SI_760, 108 0 /* terminates the list */ 109 }; 110 111 static inline u8 sis630_read(u8 reg) 112 { 113 return inb(smbus_base + reg); 114 } 115 116 static inline void sis630_write(u8 reg, u8 data) 117 { 118 outb(data, smbus_base + reg); 119 } 120 121 static int sis630_transaction_start(struct i2c_adapter *adap, int size, 122 u8 *oldclock) 123 { 124 int temp; 125 126 /* Make sure the SMBus host is ready to start transmitting. */ 127 temp = sis630_read(SMB_CNT); 128 if ((temp & (SMB_PROBE | SMB_HOSTBUSY)) != 0x00) { 129 dev_dbg(&adap->dev, "SMBus busy (%02x). Resetting...\n", temp); 130 /* kill smbus transaction */ 131 sis630_write(SMBHOST_CNT, SMB_KILL); 132 133 temp = sis630_read(SMB_CNT); 134 if (temp & (SMB_PROBE | SMB_HOSTBUSY)) { 135 dev_dbg(&adap->dev, "Failed! (%02x)\n", temp); 136 return -EBUSY; 137 } else { 138 dev_dbg(&adap->dev, "Successful!\n"); 139 } 140 } 141 142 /* save old clock, so we can prevent machine for hung */ 143 *oldclock = sis630_read(SMB_CNT); 144 145 dev_dbg(&adap->dev, "saved clock 0x%02x\n", *oldclock); 146 147 /* disable timeout interrupt, 148 * set Host Master Clock to 56KHz if requested */ 149 if (high_clock) 150 sis630_write(SMB_CNT, SMBCLK_SEL); 151 else 152 sis630_write(SMB_CNT, (*oldclock & ~MSTO_EN)); 153 154 /* clear all sticky bits */ 155 temp = sis630_read(SMB_STS); 156 sis630_write(SMB_STS, temp & 0x1e); 157 158 /* start the transaction by setting bit 4 and size */ 159 sis630_write(SMBHOST_CNT, SMB_START | (size & 0x07)); 160 161 return 0; 162 } 163 164 static int sis630_transaction_wait(struct i2c_adapter *adap, int size) 165 { 166 int temp, result = 0, timeout = 0; 167 168 /* We will always wait for a fraction of a second! */ 169 do { 170 msleep(1); 171 temp = sis630_read(SMB_STS); 172 /* check if block transmitted */ 173 if (size == SIS630_BLOCK_DATA && (temp & BYTE_DONE_STS)) 174 break; 175 } while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT)); 176 177 /* If the SMBus is still busy, we give up */ 178 if (timeout > MAX_TIMEOUT) { 179 dev_dbg(&adap->dev, "SMBus Timeout!\n"); 180 result = -ETIMEDOUT; 181 } 182 183 if (temp & SMBERR_STS) { 184 dev_dbg(&adap->dev, "Error: Failed bus transaction\n"); 185 result = -ENXIO; 186 } 187 188 if (temp & SMBCOL_STS) { 189 dev_err(&adap->dev, "Bus collision!\n"); 190 result = -EAGAIN; 191 } 192 193 return result; 194 } 195 196 static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock) 197 { 198 /* clear all status "sticky" bits */ 199 sis630_write(SMB_STS, 0xFF); 200 201 dev_dbg(&adap->dev, 202 "SMB_CNT before clock restore 0x%02x\n", sis630_read(SMB_CNT)); 203 204 /* 205 * restore old Host Master Clock if high_clock is set 206 * and oldclock was not 56KHz 207 */ 208 if (high_clock && !(oldclock & SMBCLK_SEL)) 209 sis630_write(SMB_CNT, sis630_read(SMB_CNT) & ~SMBCLK_SEL); 210 211 dev_dbg(&adap->dev, 212 "SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT)); 213 } 214 215 static int sis630_transaction(struct i2c_adapter *adap, int size) 216 { 217 int result = 0; 218 u8 oldclock = 0; 219 220 result = sis630_transaction_start(adap, size, &oldclock); 221 if (!result) { 222 result = sis630_transaction_wait(adap, size); 223 sis630_transaction_end(adap, oldclock); 224 } 225 226 return result; 227 } 228 229 static int sis630_block_data(struct i2c_adapter *adap, 230 union i2c_smbus_data *data, int read_write) 231 { 232 int i, len = 0, rc = 0; 233 u8 oldclock = 0; 234 235 if (read_write == I2C_SMBUS_WRITE) { 236 len = data->block[0]; 237 if (len < 0) 238 len = 0; 239 else if (len > 32) 240 len = 32; 241 sis630_write(SMB_COUNT, len); 242 for (i = 1; i <= len; i++) { 243 dev_dbg(&adap->dev, 244 "set data 0x%02x\n", data->block[i]); 245 /* set data */ 246 sis630_write(SMB_BYTE + (i - 1) % 8, data->block[i]); 247 if (i == 8 || (len < 8 && i == len)) { 248 dev_dbg(&adap->dev, 249 "start trans len=%d i=%d\n", len, i); 250 /* first transaction */ 251 rc = sis630_transaction_start(adap, 252 SIS630_BLOCK_DATA, &oldclock); 253 if (rc) 254 return rc; 255 } else if ((i - 1) % 8 == 7 || i == len) { 256 dev_dbg(&adap->dev, 257 "trans_wait len=%d i=%d\n", len, i); 258 if (i > 8) { 259 dev_dbg(&adap->dev, 260 "clear smbary_sts" 261 " len=%d i=%d\n", len, i); 262 /* 263 If this is not first transaction, 264 we must clear sticky bit. 265 clear SMBARY_STS 266 */ 267 sis630_write(SMB_STS, BYTE_DONE_STS); 268 } 269 rc = sis630_transaction_wait(adap, 270 SIS630_BLOCK_DATA); 271 if (rc) { 272 dev_dbg(&adap->dev, 273 "trans_wait failed\n"); 274 break; 275 } 276 } 277 } 278 } else { 279 /* read request */ 280 data->block[0] = len = 0; 281 rc = sis630_transaction_start(adap, 282 SIS630_BLOCK_DATA, &oldclock); 283 if (rc) 284 return rc; 285 do { 286 rc = sis630_transaction_wait(adap, SIS630_BLOCK_DATA); 287 if (rc) { 288 dev_dbg(&adap->dev, "trans_wait failed\n"); 289 break; 290 } 291 /* if this first transaction then read byte count */ 292 if (len == 0) 293 data->block[0] = sis630_read(SMB_COUNT); 294 295 /* just to be sure */ 296 if (data->block[0] > 32) 297 data->block[0] = 32; 298 299 dev_dbg(&adap->dev, 300 "block data read len=0x%x\n", data->block[0]); 301 302 for (i = 0; i < 8 && len < data->block[0]; i++, len++) { 303 dev_dbg(&adap->dev, 304 "read i=%d len=%d\n", i, len); 305 data->block[len + 1] = sis630_read(SMB_BYTE + 306 i); 307 } 308 309 dev_dbg(&adap->dev, 310 "clear smbary_sts len=%d i=%d\n", len, i); 311 312 /* clear SMBARY_STS */ 313 sis630_write(SMB_STS, BYTE_DONE_STS); 314 } while (len < data->block[0]); 315 } 316 317 sis630_transaction_end(adap, oldclock); 318 319 return rc; 320 } 321 322 /* Return negative errno on error. */ 323 static s32 sis630_access(struct i2c_adapter *adap, u16 addr, 324 unsigned short flags, char read_write, 325 u8 command, int size, union i2c_smbus_data *data) 326 { 327 int status; 328 329 switch (size) { 330 case I2C_SMBUS_QUICK: 331 sis630_write(SMB_ADDR, 332 ((addr & 0x7f) << 1) | (read_write & 0x01)); 333 size = SIS630_QUICK; 334 break; 335 case I2C_SMBUS_BYTE: 336 sis630_write(SMB_ADDR, 337 ((addr & 0x7f) << 1) | (read_write & 0x01)); 338 if (read_write == I2C_SMBUS_WRITE) 339 sis630_write(SMB_CMD, command); 340 size = SIS630_BYTE; 341 break; 342 case I2C_SMBUS_BYTE_DATA: 343 sis630_write(SMB_ADDR, 344 ((addr & 0x7f) << 1) | (read_write & 0x01)); 345 sis630_write(SMB_CMD, command); 346 if (read_write == I2C_SMBUS_WRITE) 347 sis630_write(SMB_BYTE, data->byte); 348 size = SIS630_BYTE_DATA; 349 break; 350 case I2C_SMBUS_PROC_CALL: 351 case I2C_SMBUS_WORD_DATA: 352 sis630_write(SMB_ADDR, 353 ((addr & 0x7f) << 1) | (read_write & 0x01)); 354 sis630_write(SMB_CMD, command); 355 if (read_write == I2C_SMBUS_WRITE) { 356 sis630_write(SMB_BYTE, data->word & 0xff); 357 sis630_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8); 358 } 359 size = (size == I2C_SMBUS_PROC_CALL ? 360 SIS630_PCALL : SIS630_WORD_DATA); 361 break; 362 case I2C_SMBUS_BLOCK_DATA: 363 sis630_write(SMB_ADDR, 364 ((addr & 0x7f) << 1) | (read_write & 0x01)); 365 sis630_write(SMB_CMD, command); 366 size = SIS630_BLOCK_DATA; 367 return sis630_block_data(adap, data, read_write); 368 default: 369 dev_warn(&adap->dev, "Unsupported transaction %d\n", size); 370 return -EOPNOTSUPP; 371 } 372 373 status = sis630_transaction(adap, size); 374 if (status) 375 return status; 376 377 if ((size != SIS630_PCALL) && 378 ((read_write == I2C_SMBUS_WRITE) || (size == SIS630_QUICK))) { 379 return 0; 380 } 381 382 switch (size) { 383 case SIS630_BYTE: 384 case SIS630_BYTE_DATA: 385 data->byte = sis630_read(SMB_BYTE); 386 break; 387 case SIS630_PCALL: 388 case SIS630_WORD_DATA: 389 data->word = sis630_read(SMB_BYTE) + 390 (sis630_read(SMB_BYTE + 1) << 8); 391 break; 392 } 393 394 return 0; 395 } 396 397 static u32 sis630_func(struct i2c_adapter *adapter) 398 { 399 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 400 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 401 I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_DATA; 402 } 403 404 static int sis630_setup(struct pci_dev *sis630_dev) 405 { 406 unsigned char b; 407 struct pci_dev *dummy = NULL; 408 int retval, i; 409 /* acpi base address */ 410 unsigned short acpi_base; 411 412 /* check for supported SiS devices */ 413 for (i = 0; supported[i] > 0; i++) { 414 dummy = pci_get_device(PCI_VENDOR_ID_SI, supported[i], dummy); 415 if (dummy) 416 break; /* found */ 417 } 418 419 if (dummy) { 420 pci_dev_put(dummy); 421 } else if (force) { 422 dev_err(&sis630_dev->dev, 423 "WARNING: Can't detect SIS630 compatible device, but " 424 "loading because of force option enabled\n"); 425 } else { 426 return -ENODEV; 427 } 428 429 /* 430 Enable ACPI first , so we can accsess reg 74-75 431 in acpi io space and read acpi base addr 432 */ 433 if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, &b)) { 434 dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n"); 435 retval = -ENODEV; 436 goto exit; 437 } 438 /* if ACPI already enabled , do nothing */ 439 if (!(b & 0x80) && 440 pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) { 441 dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n"); 442 retval = -ENODEV; 443 goto exit; 444 } 445 446 /* Determine the ACPI base address */ 447 if (pci_read_config_word(sis630_dev, 448 SIS630_ACPI_BASE_REG, &acpi_base)) { 449 dev_err(&sis630_dev->dev, 450 "Error: Can't determine ACPI base address\n"); 451 retval = -ENODEV; 452 goto exit; 453 } 454 455 dev_dbg(&sis630_dev->dev, "ACPI base at 0x%04hx\n", acpi_base); 456 457 if (supported[i] == PCI_DEVICE_ID_SI_760) 458 smbus_base = acpi_base + 0xE0; 459 else 460 smbus_base = acpi_base + 0x80; 461 462 dev_dbg(&sis630_dev->dev, "SMBus base at 0x%04hx\n", smbus_base); 463 464 retval = acpi_check_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION, 465 sis630_driver.name); 466 if (retval) 467 goto exit; 468 469 /* Everything is happy, let's grab the memory and set things up. */ 470 if (!request_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION, 471 sis630_driver.name)) { 472 dev_err(&sis630_dev->dev, 473 "I/O Region 0x%04x-0x%04x for SMBus already in use.\n", 474 smbus_base + SMB_STS, 475 smbus_base + SMB_STS + SIS630_SMB_IOREGION - 1); 476 retval = -EBUSY; 477 goto exit; 478 } 479 480 retval = 0; 481 482 exit: 483 if (retval) 484 smbus_base = 0; 485 return retval; 486 } 487 488 489 static const struct i2c_algorithm smbus_algorithm = { 490 .smbus_xfer = sis630_access, 491 .functionality = sis630_func, 492 }; 493 494 static struct i2c_adapter sis630_adapter = { 495 .owner = THIS_MODULE, 496 .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, 497 .algo = &smbus_algorithm, 498 .retries = 3 499 }; 500 501 static const struct pci_device_id sis630_ids[] = { 502 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) }, 503 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_LPC) }, 504 { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_964) }, 505 { 0, } 506 }; 507 508 MODULE_DEVICE_TABLE(pci, sis630_ids); 509 510 static int sis630_probe(struct pci_dev *dev, const struct pci_device_id *id) 511 { 512 if (sis630_setup(dev)) { 513 dev_err(&dev->dev, 514 "SIS630 compatible bus not detected, " 515 "module not inserted.\n"); 516 return -ENODEV; 517 } 518 519 /* set up the sysfs linkage to our parent device */ 520 sis630_adapter.dev.parent = &dev->dev; 521 522 snprintf(sis630_adapter.name, sizeof(sis630_adapter.name), 523 "SMBus SIS630 adapter at %04x", smbus_base + SMB_STS); 524 525 return i2c_add_adapter(&sis630_adapter); 526 } 527 528 static void sis630_remove(struct pci_dev *dev) 529 { 530 if (smbus_base) { 531 i2c_del_adapter(&sis630_adapter); 532 release_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION); 533 smbus_base = 0; 534 } 535 } 536 537 538 static struct pci_driver sis630_driver = { 539 .name = "sis630_smbus", 540 .id_table = sis630_ids, 541 .probe = sis630_probe, 542 .remove = sis630_remove, 543 }; 544 545 module_pci_driver(sis630_driver); 546 547 MODULE_LICENSE("GPL"); 548 MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>"); 549 MODULE_DESCRIPTION("SIS630 SMBus driver"); 550