1 /* 2 * PC SMBus implementation 3 * split from acpi.c 4 * 5 * Copyright (c) 2006 Fabrice Bellard 6 * 7 * This library is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License version 2.1 as published by the Free Software Foundation. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, see 18 * <http://www.gnu.org/licenses/>. 19 */ 20 21 #include "qemu/osdep.h" 22 #include "hw/boards.h" 23 #include "hw/i2c/pm_smbus.h" 24 #include "hw/i2c/smbus_master.h" 25 #include "migration/vmstate.h" 26 27 #define SMBHSTSTS 0x00 28 #define SMBHSTCNT 0x02 29 #define SMBHSTCMD 0x03 30 #define SMBHSTADD 0x04 31 #define SMBHSTDAT0 0x05 32 #define SMBHSTDAT1 0x06 33 #define SMBBLKDAT 0x07 34 #define SMBAUXCTL 0x0d 35 36 #define STS_HOST_BUSY (1 << 0) 37 #define STS_INTR (1 << 1) 38 #define STS_DEV_ERR (1 << 2) 39 #define STS_BUS_ERR (1 << 3) 40 #define STS_FAILED (1 << 4) 41 #define STS_SMBALERT (1 << 5) 42 #define STS_INUSE_STS (1 << 6) 43 #define STS_BYTE_DONE (1 << 7) 44 /* Signs of successfully transaction end : 45 * ByteDoneStatus = 1 (STS_BYTE_DONE) and INTR = 1 (STS_INTR ) 46 */ 47 48 #define CTL_INTREN (1 << 0) 49 #define CTL_KILL (1 << 1) 50 #define CTL_LAST_BYTE (1 << 5) 51 #define CTL_START (1 << 6) 52 #define CTL_PEC_EN (1 << 7) 53 #define CTL_RETURN_MASK 0x1f 54 55 #define PROT_QUICK 0 56 #define PROT_BYTE 1 57 #define PROT_BYTE_DATA 2 58 #define PROT_WORD_DATA 3 59 #define PROT_PROC_CALL 4 60 #define PROT_BLOCK_DATA 5 61 #define PROT_I2C_BLOCK_READ 6 62 63 #define AUX_PEC (1 << 0) 64 #define AUX_BLK (1 << 1) 65 #define AUX_MASK 0x3 66 67 /*#define DEBUG*/ 68 69 #ifdef DEBUG 70 # define SMBUS_DPRINTF(format, ...) printf(format, ## __VA_ARGS__) 71 #else 72 # define SMBUS_DPRINTF(format, ...) do { } while (0) 73 #endif 74 75 76 static void smb_transaction(PMSMBus *s) 77 { 78 uint8_t prot = (s->smb_ctl >> 2) & 0x07; 79 uint8_t read = s->smb_addr & 0x01; 80 uint8_t cmd = s->smb_cmd; 81 uint8_t addr = s->smb_addr >> 1; 82 I2CBus *bus = s->smbus; 83 int ret; 84 85 SMBUS_DPRINTF("SMBus trans addr=0x%02x prot=0x%02x\n", addr, prot); 86 /* Transaction isn't exec if STS_DEV_ERR bit set */ 87 if ((s->smb_stat & STS_DEV_ERR) != 0) { 88 goto error; 89 } 90 91 switch(prot) { 92 case PROT_QUICK: 93 ret = smbus_quick_command(bus, addr, read); 94 goto done; 95 case PROT_BYTE: 96 if (read) { 97 ret = smbus_receive_byte(bus, addr); 98 goto data8; 99 } else { 100 ret = smbus_send_byte(bus, addr, cmd); 101 goto done; 102 } 103 case PROT_BYTE_DATA: 104 if (read) { 105 ret = smbus_read_byte(bus, addr, cmd); 106 goto data8; 107 } else { 108 ret = smbus_write_byte(bus, addr, cmd, s->smb_data0); 109 goto done; 110 } 111 break; 112 case PROT_WORD_DATA: 113 if (read) { 114 ret = smbus_read_word(bus, addr, cmd); 115 goto data16; 116 } else { 117 ret = smbus_write_word(bus, addr, cmd, 118 (s->smb_data1 << 8) | s->smb_data0); 119 goto done; 120 } 121 break; 122 case PROT_I2C_BLOCK_READ: 123 /* According to the Linux i2c-i801 driver: 124 * NB: page 240 of ICH5 datasheet shows that the R/#W 125 * bit should be cleared here, even when reading. 126 * However if SPD Write Disable is set (Lynx Point and later), 127 * the read will fail if we don't set the R/#W bit. 128 * So at least Linux may or may not set the read bit here. 129 * So just ignore the read bit for this command. 130 */ 131 if (i2c_start_send(bus, addr)) { 132 goto error; 133 } 134 ret = i2c_send(bus, s->smb_data1); 135 if (ret) { 136 goto error; 137 } 138 if (i2c_start_recv(bus, addr)) { 139 goto error; 140 } 141 s->in_i2c_block_read = true; 142 s->smb_blkdata = i2c_recv(s->smbus); 143 s->op_done = false; 144 s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE; 145 goto out; 146 147 case PROT_BLOCK_DATA: 148 if (read) { 149 ret = smbus_read_block(bus, addr, cmd, s->smb_data, 150 sizeof(s->smb_data), !s->i2c_enable, 151 !s->i2c_enable); 152 if (ret < 0) { 153 goto error; 154 } 155 s->smb_index = 0; 156 s->op_done = false; 157 if (s->smb_auxctl & AUX_BLK) { 158 s->smb_stat |= STS_INTR; 159 } else { 160 s->smb_blkdata = s->smb_data[0]; 161 s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE; 162 } 163 s->smb_data0 = ret; 164 goto out; 165 } else { 166 if (s->smb_auxctl & AUX_BLK) { 167 if (s->smb_index != s->smb_data0) { 168 s->smb_index = 0; 169 goto error; 170 } 171 /* Data is already all written to the queue, just do 172 the operation. */ 173 s->smb_index = 0; 174 ret = smbus_write_block(bus, addr, cmd, s->smb_data, 175 s->smb_data0, !s->i2c_enable); 176 if (ret < 0) { 177 goto error; 178 } 179 s->op_done = true; 180 s->smb_stat |= STS_INTR; 181 s->smb_stat &= ~STS_HOST_BUSY; 182 } else { 183 s->op_done = false; 184 s->smb_stat |= STS_HOST_BUSY | STS_BYTE_DONE; 185 s->smb_data[0] = s->smb_blkdata; 186 s->smb_index = 0; 187 } 188 goto out; 189 } 190 break; 191 default: 192 goto error; 193 } 194 abort(); 195 196 data16: 197 if (ret < 0) { 198 goto error; 199 } 200 s->smb_data1 = ret >> 8; 201 data8: 202 if (ret < 0) { 203 goto error; 204 } 205 s->smb_data0 = ret; 206 done: 207 if (ret < 0) { 208 goto error; 209 } 210 s->smb_stat |= STS_INTR; 211 out: 212 return; 213 214 error: 215 s->smb_stat |= STS_DEV_ERR; 216 return; 217 } 218 219 static void smb_transaction_start(PMSMBus *s) 220 { 221 if (s->smb_ctl & CTL_INTREN) { 222 smb_transaction(s); 223 s->start_transaction_on_status_read = false; 224 } else { 225 /* Do not execute immediately the command; it will be 226 * executed when guest will read SMB_STAT register. This 227 * is to work around a bug in AMIBIOS (that is working 228 * around another bug in some specific hardware) where 229 * it waits for STS_HOST_BUSY to be set before waiting 230 * checking for status. If STS_HOST_BUSY doesn't get 231 * set, it gets stuck. */ 232 s->smb_stat |= STS_HOST_BUSY; 233 s->start_transaction_on_status_read = true; 234 } 235 } 236 237 static bool 238 smb_irq_value(PMSMBus *s) 239 { 240 return ((s->smb_stat & ~STS_HOST_BUSY) != 0) && (s->smb_ctl & CTL_INTREN); 241 } 242 243 static bool 244 smb_byte_by_byte(PMSMBus *s) 245 { 246 if (s->op_done) { 247 return false; 248 } 249 if (s->in_i2c_block_read) { 250 return true; 251 } 252 return !(s->smb_auxctl & AUX_BLK); 253 } 254 255 static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val, 256 unsigned width) 257 { 258 PMSMBus *s = opaque; 259 uint8_t clear_byte_done; 260 261 SMBUS_DPRINTF("SMB writeb port=0x%04" HWADDR_PRIx 262 " val=0x%02" PRIx64 "\n", addr, val); 263 switch(addr) { 264 case SMBHSTSTS: 265 clear_byte_done = s->smb_stat & val & STS_BYTE_DONE; 266 s->smb_stat &= ~(val & ~STS_HOST_BUSY); 267 if (clear_byte_done && smb_byte_by_byte(s)) { 268 uint8_t read = s->smb_addr & 0x01; 269 270 if (s->in_i2c_block_read) { 271 /* See comment below PROT_I2C_BLOCK_READ above. */ 272 read = 1; 273 } 274 275 s->smb_index++; 276 if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) { 277 s->smb_index = 0; 278 } 279 if (!read && s->smb_index == s->smb_data0) { 280 uint8_t prot = (s->smb_ctl >> 2) & 0x07; 281 uint8_t cmd = s->smb_cmd; 282 uint8_t addr = s->smb_addr >> 1; 283 int ret; 284 285 if (prot == PROT_I2C_BLOCK_READ) { 286 s->smb_stat |= STS_DEV_ERR; 287 goto out; 288 } 289 290 ret = smbus_write_block(s->smbus, addr, cmd, s->smb_data, 291 s->smb_data0, !s->i2c_enable); 292 if (ret < 0) { 293 s->smb_stat |= STS_DEV_ERR; 294 goto out; 295 } 296 s->op_done = true; 297 s->smb_stat |= STS_INTR; 298 s->smb_stat &= ~STS_HOST_BUSY; 299 } else if (!read) { 300 s->smb_data[s->smb_index] = s->smb_blkdata; 301 s->smb_stat |= STS_BYTE_DONE; 302 } else if (s->smb_ctl & CTL_LAST_BYTE) { 303 s->op_done = true; 304 if (s->in_i2c_block_read) { 305 s->in_i2c_block_read = false; 306 s->smb_blkdata = i2c_recv(s->smbus); 307 i2c_nack(s->smbus); 308 i2c_end_transfer(s->smbus); 309 } else { 310 s->smb_blkdata = s->smb_data[s->smb_index]; 311 } 312 s->smb_index = 0; 313 s->smb_stat |= STS_INTR; 314 s->smb_stat &= ~STS_HOST_BUSY; 315 } else { 316 if (s->in_i2c_block_read) { 317 s->smb_blkdata = i2c_recv(s->smbus); 318 } else { 319 s->smb_blkdata = s->smb_data[s->smb_index]; 320 } 321 s->smb_stat |= STS_BYTE_DONE; 322 } 323 } 324 break; 325 case SMBHSTCNT: 326 s->smb_ctl = val & ~CTL_START; /* CTL_START always reads 0 */ 327 if (val & CTL_START) { 328 if (!s->op_done) { 329 s->smb_index = 0; 330 s->op_done = true; 331 if (s->in_i2c_block_read) { 332 s->in_i2c_block_read = false; 333 i2c_end_transfer(s->smbus); 334 } 335 } 336 smb_transaction_start(s); 337 } 338 if (s->smb_ctl & CTL_KILL) { 339 s->op_done = true; 340 s->smb_index = 0; 341 s->smb_stat |= STS_FAILED; 342 s->smb_stat &= ~STS_HOST_BUSY; 343 } 344 break; 345 case SMBHSTCMD: 346 s->smb_cmd = val; 347 break; 348 case SMBHSTADD: 349 s->smb_addr = val; 350 break; 351 case SMBHSTDAT0: 352 s->smb_data0 = val; 353 break; 354 case SMBHSTDAT1: 355 s->smb_data1 = val; 356 break; 357 case SMBBLKDAT: 358 if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) { 359 s->smb_index = 0; 360 } 361 if (s->smb_auxctl & AUX_BLK) { 362 s->smb_data[s->smb_index++] = val; 363 } else { 364 s->smb_blkdata = val; 365 } 366 break; 367 case SMBAUXCTL: 368 s->smb_auxctl = val & AUX_MASK; 369 break; 370 default: 371 break; 372 } 373 374 out: 375 if (s->set_irq) { 376 s->set_irq(s, smb_irq_value(s)); 377 } 378 } 379 380 static uint64_t smb_ioport_readb(void *opaque, hwaddr addr, unsigned width) 381 { 382 PMSMBus *s = opaque; 383 uint32_t val; 384 385 switch(addr) { 386 case SMBHSTSTS: 387 val = s->smb_stat; 388 if (s->start_transaction_on_status_read) { 389 /* execute command now */ 390 s->start_transaction_on_status_read = false; 391 s->smb_stat &= ~STS_HOST_BUSY; 392 smb_transaction(s); 393 } 394 break; 395 case SMBHSTCNT: 396 val = s->smb_ctl & CTL_RETURN_MASK; 397 break; 398 case SMBHSTCMD: 399 val = s->smb_cmd; 400 break; 401 case SMBHSTADD: 402 val = s->smb_addr; 403 break; 404 case SMBHSTDAT0: 405 val = s->smb_data0; 406 break; 407 case SMBHSTDAT1: 408 val = s->smb_data1; 409 break; 410 case SMBBLKDAT: 411 if (s->smb_auxctl & AUX_BLK && !s->in_i2c_block_read) { 412 if (s->smb_index >= PM_SMBUS_MAX_MSG_SIZE) { 413 s->smb_index = 0; 414 } 415 val = s->smb_data[s->smb_index++]; 416 if (!s->op_done && s->smb_index == s->smb_data0) { 417 s->op_done = true; 418 s->smb_index = 0; 419 s->smb_stat &= ~STS_HOST_BUSY; 420 } 421 } else { 422 val = s->smb_blkdata; 423 } 424 break; 425 case SMBAUXCTL: 426 val = s->smb_auxctl; 427 break; 428 default: 429 val = 0; 430 break; 431 } 432 SMBUS_DPRINTF("SMB readb port=0x%04" HWADDR_PRIx " val=0x%02x\n", 433 addr, val); 434 435 if (s->set_irq) { 436 s->set_irq(s, smb_irq_value(s)); 437 } 438 439 return val; 440 } 441 442 static void pm_smbus_reset(PMSMBus *s) 443 { 444 s->op_done = true; 445 s->smb_index = 0; 446 s->smb_stat = 0; 447 } 448 449 static const MemoryRegionOps pm_smbus_ops = { 450 .read = smb_ioport_readb, 451 .write = smb_ioport_writeb, 452 .valid.min_access_size = 1, 453 .valid.max_access_size = 1, 454 .endianness = DEVICE_LITTLE_ENDIAN, 455 }; 456 457 bool pm_smbus_vmstate_needed(void) 458 { 459 MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine()); 460 461 return !mc->smbus_no_migration_support; 462 } 463 464 const VMStateDescription pmsmb_vmstate = { 465 .name = "pmsmb", 466 .version_id = 1, 467 .minimum_version_id = 1, 468 .fields = (VMStateField[]) { 469 VMSTATE_UINT8(smb_stat, PMSMBus), 470 VMSTATE_UINT8(smb_ctl, PMSMBus), 471 VMSTATE_UINT8(smb_cmd, PMSMBus), 472 VMSTATE_UINT8(smb_addr, PMSMBus), 473 VMSTATE_UINT8(smb_data0, PMSMBus), 474 VMSTATE_UINT8(smb_data1, PMSMBus), 475 VMSTATE_UINT32(smb_index, PMSMBus), 476 VMSTATE_UINT8_ARRAY(smb_data, PMSMBus, PM_SMBUS_MAX_MSG_SIZE), 477 VMSTATE_UINT8(smb_auxctl, PMSMBus), 478 VMSTATE_UINT8(smb_blkdata, PMSMBus), 479 VMSTATE_BOOL(i2c_enable, PMSMBus), 480 VMSTATE_BOOL(op_done, PMSMBus), 481 VMSTATE_BOOL(in_i2c_block_read, PMSMBus), 482 VMSTATE_BOOL(start_transaction_on_status_read, PMSMBus), 483 VMSTATE_END_OF_LIST() 484 } 485 }; 486 487 void pm_smbus_init(DeviceState *parent, PMSMBus *smb, bool force_aux_blk) 488 { 489 smb->op_done = true; 490 smb->reset = pm_smbus_reset; 491 smb->smbus = i2c_init_bus(parent, "i2c"); 492 if (force_aux_blk) { 493 smb->smb_auxctl |= AUX_BLK; 494 } 495 memory_region_init_io(&smb->io, OBJECT(parent), &pm_smbus_ops, smb, 496 "pm-smbus", 64); 497 } 498