1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * PowerMac G5 SMU driver 4 * 5 * Copyright 2004 J. Mayer <l_indien@magic.fr> 6 * Copyright 2005 Benjamin Herrenschmidt, IBM Corp. 7 */ 8 9 /* 10 * TODO: 11 * - maybe add timeout to commands ? 12 * - blocking version of time functions 13 * - polling version of i2c commands (including timer that works with 14 * interrupts off) 15 * - maybe avoid some data copies with i2c by directly using the smu cmd 16 * buffer and a lower level internal interface 17 * - understand SMU -> CPU events and implement reception of them via 18 * the userland interface 19 */ 20 21 #include <linux/types.h> 22 #include <linux/kernel.h> 23 #include <linux/device.h> 24 #include <linux/dmapool.h> 25 #include <linux/memblock.h> 26 #include <linux/vmalloc.h> 27 #include <linux/highmem.h> 28 #include <linux/jiffies.h> 29 #include <linux/interrupt.h> 30 #include <linux/rtc.h> 31 #include <linux/completion.h> 32 #include <linux/miscdevice.h> 33 #include <linux/delay.h> 34 #include <linux/poll.h> 35 #include <linux/mutex.h> 36 #include <linux/of.h> 37 #include <linux/of_address.h> 38 #include <linux/of_irq.h> 39 #include <linux/of_platform.h> 40 #include <linux/platform_device.h> 41 #include <linux/slab.h> 42 #include <linux/sched/signal.h> 43 44 #include <asm/byteorder.h> 45 #include <asm/io.h> 46 #include <asm/machdep.h> 47 #include <asm/pmac_feature.h> 48 #include <asm/smu.h> 49 #include <asm/sections.h> 50 #include <linux/uaccess.h> 51 52 #define VERSION "0.7" 53 #define AUTHOR "(c) 2005 Benjamin Herrenschmidt, IBM Corp." 54 55 #undef DEBUG_SMU 56 57 #ifdef DEBUG_SMU 58 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0) 59 #else 60 #define DPRINTK(fmt, args...) do { } while (0) 61 #endif 62 63 /* 64 * This is the command buffer passed to the SMU hardware 65 */ 66 #define SMU_MAX_DATA 254 67 68 struct smu_cmd_buf { 69 u8 cmd; 70 u8 length; 71 u8 data[SMU_MAX_DATA]; 72 }; 73 74 struct smu_device { 75 spinlock_t lock; 76 struct device_node *of_node; 77 struct platform_device *of_dev; 78 int doorbell; /* doorbell gpio */ 79 u32 __iomem *db_buf; /* doorbell buffer */ 80 struct device_node *db_node; 81 unsigned int db_irq; 82 int msg; 83 struct device_node *msg_node; 84 unsigned int msg_irq; 85 struct smu_cmd_buf *cmd_buf; /* command buffer virtual */ 86 u32 cmd_buf_abs; /* command buffer absolute */ 87 struct list_head cmd_list; 88 struct smu_cmd *cmd_cur; /* pending command */ 89 int broken_nap; 90 struct list_head cmd_i2c_list; 91 struct smu_i2c_cmd *cmd_i2c_cur; /* pending i2c command */ 92 struct timer_list i2c_timer; 93 }; 94 95 /* 96 * I don't think there will ever be more than one SMU, so 97 * for now, just hard code that 98 */ 99 static DEFINE_MUTEX(smu_mutex); 100 static struct smu_device *smu; 101 static DEFINE_MUTEX(smu_part_access); 102 static int smu_irq_inited; 103 static unsigned long smu_cmdbuf_abs; 104 105 static void smu_i2c_retry(struct timer_list *t); 106 107 /* 108 * SMU driver low level stuff 109 */ 110 111 static void smu_start_cmd(void) 112 { 113 unsigned long faddr, fend; 114 struct smu_cmd *cmd; 115 116 if (list_empty(&smu->cmd_list)) 117 return; 118 119 /* Fetch first command in queue */ 120 cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link); 121 smu->cmd_cur = cmd; 122 list_del(&cmd->link); 123 124 DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd, 125 cmd->data_len); 126 DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf); 127 128 /* Fill the SMU command buffer */ 129 smu->cmd_buf->cmd = cmd->cmd; 130 smu->cmd_buf->length = cmd->data_len; 131 memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len); 132 133 /* Flush command and data to RAM */ 134 faddr = (unsigned long)smu->cmd_buf; 135 fend = faddr + smu->cmd_buf->length + 2; 136 flush_dcache_range(faddr, fend); 137 138 139 /* We also disable NAP mode for the duration of the command 140 * on U3 based machines. 141 * This is slightly racy as it can be written back to 1 by a sysctl 142 * but that never happens in practice. There seem to be an issue with 143 * U3 based machines such as the iMac G5 where napping for the 144 * whole duration of the command prevents the SMU from fetching it 145 * from memory. This might be related to the strange i2c based 146 * mechanism the SMU uses to access memory. 147 */ 148 if (smu->broken_nap) 149 powersave_nap = 0; 150 151 /* This isn't exactly a DMA mapping here, I suspect 152 * the SMU is actually communicating with us via i2c to the 153 * northbridge or the CPU to access RAM. 154 */ 155 writel(smu->cmd_buf_abs, smu->db_buf); 156 157 /* Ring the SMU doorbell */ 158 pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4); 159 } 160 161 162 static irqreturn_t smu_db_intr(int irq, void *arg) 163 { 164 unsigned long flags; 165 struct smu_cmd *cmd; 166 void (*done)(struct smu_cmd *cmd, void *misc) = NULL; 167 void *misc = NULL; 168 u8 gpio; 169 int rc = 0; 170 171 /* SMU completed the command, well, we hope, let's make sure 172 * of it 173 */ 174 spin_lock_irqsave(&smu->lock, flags); 175 176 gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell); 177 if ((gpio & 7) != 7) { 178 spin_unlock_irqrestore(&smu->lock, flags); 179 return IRQ_HANDLED; 180 } 181 182 cmd = smu->cmd_cur; 183 smu->cmd_cur = NULL; 184 if (cmd == NULL) 185 goto bail; 186 187 if (rc == 0) { 188 unsigned long faddr; 189 int reply_len; 190 u8 ack; 191 192 /* CPU might have brought back the cache line, so we need 193 * to flush again before peeking at the SMU response. We 194 * flush the entire buffer for now as we haven't read the 195 * reply length (it's only 2 cache lines anyway) 196 */ 197 faddr = (unsigned long)smu->cmd_buf; 198 flush_dcache_range(faddr, faddr + 256); 199 200 /* Now check ack */ 201 ack = (~cmd->cmd) & 0xff; 202 if (ack != smu->cmd_buf->cmd) { 203 DPRINTK("SMU: incorrect ack, want %x got %x\n", 204 ack, smu->cmd_buf->cmd); 205 rc = -EIO; 206 } 207 reply_len = rc == 0 ? smu->cmd_buf->length : 0; 208 DPRINTK("SMU: reply len: %d\n", reply_len); 209 if (reply_len > cmd->reply_len) { 210 printk(KERN_WARNING "SMU: reply buffer too small," 211 "got %d bytes for a %d bytes buffer\n", 212 reply_len, cmd->reply_len); 213 reply_len = cmd->reply_len; 214 } 215 cmd->reply_len = reply_len; 216 if (cmd->reply_buf && reply_len) 217 memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len); 218 } 219 220 /* Now complete the command. Write status last in order as we lost 221 * ownership of the command structure as soon as it's no longer -1 222 */ 223 done = cmd->done; 224 misc = cmd->misc; 225 mb(); 226 cmd->status = rc; 227 228 /* Re-enable NAP mode */ 229 if (smu->broken_nap) 230 powersave_nap = 1; 231 bail: 232 /* Start next command if any */ 233 smu_start_cmd(); 234 spin_unlock_irqrestore(&smu->lock, flags); 235 236 /* Call command completion handler if any */ 237 if (done) 238 done(cmd, misc); 239 240 /* It's an edge interrupt, nothing to do */ 241 return IRQ_HANDLED; 242 } 243 244 245 static irqreturn_t smu_msg_intr(int irq, void *arg) 246 { 247 /* I don't quite know what to do with this one, we seem to never 248 * receive it, so I suspect we have to arm it someway in the SMU 249 * to start getting events that way. 250 */ 251 252 printk(KERN_INFO "SMU: message interrupt !\n"); 253 254 /* It's an edge interrupt, nothing to do */ 255 return IRQ_HANDLED; 256 } 257 258 259 /* 260 * Queued command management. 261 * 262 */ 263 264 int smu_queue_cmd(struct smu_cmd *cmd) 265 { 266 unsigned long flags; 267 268 if (smu == NULL) 269 return -ENODEV; 270 if (cmd->data_len > SMU_MAX_DATA || 271 cmd->reply_len > SMU_MAX_DATA) 272 return -EINVAL; 273 274 cmd->status = 1; 275 spin_lock_irqsave(&smu->lock, flags); 276 list_add_tail(&cmd->link, &smu->cmd_list); 277 if (smu->cmd_cur == NULL) 278 smu_start_cmd(); 279 spin_unlock_irqrestore(&smu->lock, flags); 280 281 /* Workaround for early calls when irq isn't available */ 282 if (!smu_irq_inited || !smu->db_irq) 283 smu_spinwait_cmd(cmd); 284 285 return 0; 286 } 287 EXPORT_SYMBOL(smu_queue_cmd); 288 289 290 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command, 291 unsigned int data_len, 292 void (*done)(struct smu_cmd *cmd, void *misc), 293 void *misc, ...) 294 { 295 struct smu_cmd *cmd = &scmd->cmd; 296 va_list list; 297 int i; 298 299 if (data_len > sizeof(scmd->buffer)) 300 return -EINVAL; 301 302 memset(scmd, 0, sizeof(*scmd)); 303 cmd->cmd = command; 304 cmd->data_len = data_len; 305 cmd->data_buf = scmd->buffer; 306 cmd->reply_len = sizeof(scmd->buffer); 307 cmd->reply_buf = scmd->buffer; 308 cmd->done = done; 309 cmd->misc = misc; 310 311 va_start(list, misc); 312 for (i = 0; i < data_len; ++i) 313 scmd->buffer[i] = (u8)va_arg(list, int); 314 va_end(list); 315 316 return smu_queue_cmd(cmd); 317 } 318 EXPORT_SYMBOL(smu_queue_simple); 319 320 321 void smu_poll(void) 322 { 323 u8 gpio; 324 325 if (smu == NULL) 326 return; 327 328 gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell); 329 if ((gpio & 7) == 7) 330 smu_db_intr(smu->db_irq, smu); 331 } 332 EXPORT_SYMBOL(smu_poll); 333 334 335 void smu_done_complete(struct smu_cmd *cmd, void *misc) 336 { 337 struct completion *comp = misc; 338 339 complete(comp); 340 } 341 EXPORT_SYMBOL(smu_done_complete); 342 343 344 void smu_spinwait_cmd(struct smu_cmd *cmd) 345 { 346 while(cmd->status == 1) 347 smu_poll(); 348 } 349 EXPORT_SYMBOL(smu_spinwait_cmd); 350 351 352 /* RTC low level commands */ 353 static inline int bcd2hex (int n) 354 { 355 return (((n & 0xf0) >> 4) * 10) + (n & 0xf); 356 } 357 358 359 static inline int hex2bcd (int n) 360 { 361 return ((n / 10) << 4) + (n % 10); 362 } 363 364 365 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf, 366 struct rtc_time *time) 367 { 368 cmd_buf->cmd = 0x8e; 369 cmd_buf->length = 8; 370 cmd_buf->data[0] = 0x80; 371 cmd_buf->data[1] = hex2bcd(time->tm_sec); 372 cmd_buf->data[2] = hex2bcd(time->tm_min); 373 cmd_buf->data[3] = hex2bcd(time->tm_hour); 374 cmd_buf->data[4] = time->tm_wday; 375 cmd_buf->data[5] = hex2bcd(time->tm_mday); 376 cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1; 377 cmd_buf->data[7] = hex2bcd(time->tm_year - 100); 378 } 379 380 381 int smu_get_rtc_time(struct rtc_time *time, int spinwait) 382 { 383 struct smu_simple_cmd cmd; 384 int rc; 385 386 if (smu == NULL) 387 return -ENODEV; 388 389 memset(time, 0, sizeof(struct rtc_time)); 390 rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL, 391 SMU_CMD_RTC_GET_DATETIME); 392 if (rc) 393 return rc; 394 smu_spinwait_simple(&cmd); 395 396 time->tm_sec = bcd2hex(cmd.buffer[0]); 397 time->tm_min = bcd2hex(cmd.buffer[1]); 398 time->tm_hour = bcd2hex(cmd.buffer[2]); 399 time->tm_wday = bcd2hex(cmd.buffer[3]); 400 time->tm_mday = bcd2hex(cmd.buffer[4]); 401 time->tm_mon = bcd2hex(cmd.buffer[5]) - 1; 402 time->tm_year = bcd2hex(cmd.buffer[6]) + 100; 403 404 return 0; 405 } 406 407 408 int smu_set_rtc_time(struct rtc_time *time, int spinwait) 409 { 410 struct smu_simple_cmd cmd; 411 int rc; 412 413 if (smu == NULL) 414 return -ENODEV; 415 416 rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL, 417 SMU_CMD_RTC_SET_DATETIME, 418 hex2bcd(time->tm_sec), 419 hex2bcd(time->tm_min), 420 hex2bcd(time->tm_hour), 421 time->tm_wday, 422 hex2bcd(time->tm_mday), 423 hex2bcd(time->tm_mon) + 1, 424 hex2bcd(time->tm_year - 100)); 425 if (rc) 426 return rc; 427 smu_spinwait_simple(&cmd); 428 429 return 0; 430 } 431 432 433 void smu_shutdown(void) 434 { 435 struct smu_simple_cmd cmd; 436 437 if (smu == NULL) 438 return; 439 440 if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL, 441 'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0)) 442 return; 443 smu_spinwait_simple(&cmd); 444 for (;;) 445 ; 446 } 447 448 449 void smu_restart(void) 450 { 451 struct smu_simple_cmd cmd; 452 453 if (smu == NULL) 454 return; 455 456 if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL, 457 'R', 'E', 'S', 'T', 'A', 'R', 'T', 0)) 458 return; 459 smu_spinwait_simple(&cmd); 460 for (;;) 461 ; 462 } 463 464 465 int smu_present(void) 466 { 467 return smu != NULL; 468 } 469 EXPORT_SYMBOL(smu_present); 470 471 472 int __init smu_init (void) 473 { 474 struct device_node *np; 475 u64 data; 476 int ret = 0; 477 478 np = of_find_node_by_type(NULL, "smu"); 479 if (np == NULL) 480 return -ENODEV; 481 482 printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR); 483 484 /* 485 * SMU based G5s need some memory below 2Gb. Thankfully this is 486 * called at a time where memblock is still available. 487 */ 488 smu_cmdbuf_abs = memblock_phys_alloc_range(4096, 4096, 0, 0x80000000UL); 489 if (smu_cmdbuf_abs == 0) { 490 printk(KERN_ERR "SMU: Command buffer allocation failed !\n"); 491 ret = -EINVAL; 492 goto fail_np; 493 } 494 495 smu = memblock_alloc(sizeof(struct smu_device), SMP_CACHE_BYTES); 496 if (!smu) 497 panic("%s: Failed to allocate %zu bytes\n", __func__, 498 sizeof(struct smu_device)); 499 500 spin_lock_init(&smu->lock); 501 INIT_LIST_HEAD(&smu->cmd_list); 502 INIT_LIST_HEAD(&smu->cmd_i2c_list); 503 smu->of_node = np; 504 smu->db_irq = 0; 505 smu->msg_irq = 0; 506 507 /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a 508 * 32 bits value safely 509 */ 510 smu->cmd_buf_abs = (u32)smu_cmdbuf_abs; 511 smu->cmd_buf = __va(smu_cmdbuf_abs); 512 513 smu->db_node = of_find_node_by_name(NULL, "smu-doorbell"); 514 if (smu->db_node == NULL) { 515 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n"); 516 ret = -ENXIO; 517 goto fail_bootmem; 518 } 519 if (of_property_read_reg(smu->db_node, 0, &data, NULL)) { 520 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n"); 521 ret = -ENXIO; 522 goto fail_db_node; 523 } 524 525 /* Current setup has one doorbell GPIO that does both doorbell 526 * and ack. GPIOs are at 0x50, best would be to find that out 527 * in the device-tree though. 528 */ 529 smu->doorbell = data; 530 if (smu->doorbell < 0x50) 531 smu->doorbell += 0x50; 532 533 /* Now look for the smu-interrupt GPIO */ 534 do { 535 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt"); 536 if (smu->msg_node == NULL) 537 break; 538 if (of_property_read_reg(smu->msg_node, 0, &data, NULL)) { 539 of_node_put(smu->msg_node); 540 smu->msg_node = NULL; 541 break; 542 } 543 smu->msg = data; 544 if (smu->msg < 0x50) 545 smu->msg += 0x50; 546 } while(0); 547 548 /* Doorbell buffer is currently hard-coded, I didn't find a proper 549 * device-tree entry giving the address. Best would probably to use 550 * an offset for K2 base though, but let's do it that way for now. 551 */ 552 smu->db_buf = ioremap(0x8000860c, 0x1000); 553 if (smu->db_buf == NULL) { 554 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n"); 555 ret = -ENXIO; 556 goto fail_msg_node; 557 } 558 559 /* U3 has an issue with NAP mode when issuing SMU commands */ 560 smu->broken_nap = pmac_get_uninorth_variant() < 4; 561 if (smu->broken_nap) 562 printk(KERN_INFO "SMU: using NAP mode workaround\n"); 563 564 sys_ctrler = SYS_CTRLER_SMU; 565 return 0; 566 567 fail_msg_node: 568 of_node_put(smu->msg_node); 569 fail_db_node: 570 of_node_put(smu->db_node); 571 fail_bootmem: 572 memblock_free(smu, sizeof(struct smu_device)); 573 smu = NULL; 574 fail_np: 575 of_node_put(np); 576 return ret; 577 } 578 579 580 static int smu_late_init(void) 581 { 582 if (!smu) 583 return 0; 584 585 timer_setup(&smu->i2c_timer, smu_i2c_retry, 0); 586 587 if (smu->db_node) { 588 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0); 589 if (!smu->db_irq) 590 printk(KERN_ERR "smu: failed to map irq for node %pOF\n", 591 smu->db_node); 592 } 593 if (smu->msg_node) { 594 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0); 595 if (!smu->msg_irq) 596 printk(KERN_ERR "smu: failed to map irq for node %pOF\n", 597 smu->msg_node); 598 } 599 600 /* 601 * Try to request the interrupts 602 */ 603 604 if (smu->db_irq) { 605 if (request_irq(smu->db_irq, smu_db_intr, 606 IRQF_SHARED, "SMU doorbell", smu) < 0) { 607 printk(KERN_WARNING "SMU: can't " 608 "request interrupt %d\n", 609 smu->db_irq); 610 smu->db_irq = 0; 611 } 612 } 613 614 if (smu->msg_irq) { 615 if (request_irq(smu->msg_irq, smu_msg_intr, 616 IRQF_SHARED, "SMU message", smu) < 0) { 617 printk(KERN_WARNING "SMU: can't " 618 "request interrupt %d\n", 619 smu->msg_irq); 620 smu->msg_irq = 0; 621 } 622 } 623 624 smu_irq_inited = 1; 625 return 0; 626 } 627 /* This has to be before arch_initcall as the low i2c stuff relies on the 628 * above having been done before we reach arch_initcalls 629 */ 630 core_initcall(smu_late_init); 631 632 /* 633 * sysfs visibility 634 */ 635 636 static void smu_expose_childs(struct work_struct *unused) 637 { 638 struct device_node *np; 639 640 for_each_child_of_node(smu->of_node, np) 641 if (of_device_is_compatible(np, "smu-sensors")) 642 of_platform_device_create(np, "smu-sensors", 643 &smu->of_dev->dev); 644 } 645 646 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs); 647 648 static int smu_platform_probe(struct platform_device* dev) 649 { 650 if (!smu) 651 return -ENODEV; 652 smu->of_dev = dev; 653 654 /* 655 * Ok, we are matched, now expose all i2c busses. We have to defer 656 * that unfortunately or it would deadlock inside the device model 657 */ 658 schedule_work(&smu_expose_childs_work); 659 660 return 0; 661 } 662 663 static const struct of_device_id smu_platform_match[] = 664 { 665 { 666 .type = "smu", 667 }, 668 {}, 669 }; 670 671 static struct platform_driver smu_of_platform_driver = 672 { 673 .driver = { 674 .name = "smu", 675 .of_match_table = smu_platform_match, 676 }, 677 .probe = smu_platform_probe, 678 }; 679 680 static int __init smu_init_sysfs(void) 681 { 682 /* 683 * For now, we don't power manage machines with an SMU chip, 684 * I'm a bit too far from figuring out how that works with those 685 * new chipsets, but that will come back and bite us 686 */ 687 platform_driver_register(&smu_of_platform_driver); 688 return 0; 689 } 690 691 device_initcall(smu_init_sysfs); 692 693 struct platform_device *smu_get_ofdev(void) 694 { 695 if (!smu) 696 return NULL; 697 return smu->of_dev; 698 } 699 700 EXPORT_SYMBOL_GPL(smu_get_ofdev); 701 702 /* 703 * i2c interface 704 */ 705 706 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail) 707 { 708 void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done; 709 void *misc = cmd->misc; 710 unsigned long flags; 711 712 /* Check for read case */ 713 if (!fail && cmd->read) { 714 if (cmd->pdata[0] < 1) 715 fail = 1; 716 else 717 memcpy(cmd->info.data, &cmd->pdata[1], 718 cmd->info.datalen); 719 } 720 721 DPRINTK("SMU: completing, success: %d\n", !fail); 722 723 /* Update status and mark no pending i2c command with lock 724 * held so nobody comes in while we dequeue an eventual 725 * pending next i2c command 726 */ 727 spin_lock_irqsave(&smu->lock, flags); 728 smu->cmd_i2c_cur = NULL; 729 wmb(); 730 cmd->status = fail ? -EIO : 0; 731 732 /* Is there another i2c command waiting ? */ 733 if (!list_empty(&smu->cmd_i2c_list)) { 734 struct smu_i2c_cmd *newcmd; 735 736 /* Fetch it, new current, remove from list */ 737 newcmd = list_entry(smu->cmd_i2c_list.next, 738 struct smu_i2c_cmd, link); 739 smu->cmd_i2c_cur = newcmd; 740 list_del(&cmd->link); 741 742 /* Queue with low level smu */ 743 list_add_tail(&cmd->scmd.link, &smu->cmd_list); 744 if (smu->cmd_cur == NULL) 745 smu_start_cmd(); 746 } 747 spin_unlock_irqrestore(&smu->lock, flags); 748 749 /* Call command completion handler if any */ 750 if (done) 751 done(cmd, misc); 752 753 } 754 755 756 static void smu_i2c_retry(struct timer_list *unused) 757 { 758 struct smu_i2c_cmd *cmd = smu->cmd_i2c_cur; 759 760 DPRINTK("SMU: i2c failure, requeuing...\n"); 761 762 /* requeue command simply by resetting reply_len */ 763 cmd->pdata[0] = 0xff; 764 cmd->scmd.reply_len = sizeof(cmd->pdata); 765 smu_queue_cmd(&cmd->scmd); 766 } 767 768 769 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc) 770 { 771 struct smu_i2c_cmd *cmd = misc; 772 int fail = 0; 773 774 DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n", 775 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len); 776 777 /* Check for possible status */ 778 if (scmd->status < 0) 779 fail = 1; 780 else if (cmd->read) { 781 if (cmd->stage == 0) 782 fail = cmd->pdata[0] != 0; 783 else 784 fail = cmd->pdata[0] >= 0x80; 785 } else { 786 fail = cmd->pdata[0] != 0; 787 } 788 789 /* Handle failures by requeuing command, after 5ms interval 790 */ 791 if (fail && --cmd->retries > 0) { 792 DPRINTK("SMU: i2c failure, starting timer...\n"); 793 BUG_ON(cmd != smu->cmd_i2c_cur); 794 if (!smu_irq_inited) { 795 mdelay(5); 796 smu_i2c_retry(NULL); 797 return; 798 } 799 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5)); 800 return; 801 } 802 803 /* If failure or stage 1, command is complete */ 804 if (fail || cmd->stage != 0) { 805 smu_i2c_complete_command(cmd, fail); 806 return; 807 } 808 809 DPRINTK("SMU: going to stage 1\n"); 810 811 /* Ok, initial command complete, now poll status */ 812 scmd->reply_buf = cmd->pdata; 813 scmd->reply_len = sizeof(cmd->pdata); 814 scmd->data_buf = cmd->pdata; 815 scmd->data_len = 1; 816 cmd->pdata[0] = 0; 817 cmd->stage = 1; 818 cmd->retries = 20; 819 smu_queue_cmd(scmd); 820 } 821 822 823 int smu_queue_i2c(struct smu_i2c_cmd *cmd) 824 { 825 unsigned long flags; 826 827 if (smu == NULL) 828 return -ENODEV; 829 830 /* Fill most fields of scmd */ 831 cmd->scmd.cmd = SMU_CMD_I2C_COMMAND; 832 cmd->scmd.done = smu_i2c_low_completion; 833 cmd->scmd.misc = cmd; 834 cmd->scmd.reply_buf = cmd->pdata; 835 cmd->scmd.reply_len = sizeof(cmd->pdata); 836 cmd->scmd.data_buf = (u8 *)(char *)&cmd->info; 837 cmd->scmd.status = 1; 838 cmd->stage = 0; 839 cmd->pdata[0] = 0xff; 840 cmd->retries = 20; 841 cmd->status = 1; 842 843 /* Check transfer type, sanitize some "info" fields 844 * based on transfer type and do more checking 845 */ 846 cmd->info.caddr = cmd->info.devaddr; 847 cmd->read = cmd->info.devaddr & 0x01; 848 switch(cmd->info.type) { 849 case SMU_I2C_TRANSFER_SIMPLE: 850 cmd->info.sublen = 0; 851 memset(cmd->info.subaddr, 0, sizeof(cmd->info.subaddr)); 852 break; 853 case SMU_I2C_TRANSFER_COMBINED: 854 cmd->info.devaddr &= 0xfe; 855 fallthrough; 856 case SMU_I2C_TRANSFER_STDSUB: 857 if (cmd->info.sublen > 3) 858 return -EINVAL; 859 break; 860 default: 861 return -EINVAL; 862 } 863 864 /* Finish setting up command based on transfer direction 865 */ 866 if (cmd->read) { 867 if (cmd->info.datalen > SMU_I2C_READ_MAX) 868 return -EINVAL; 869 memset(cmd->info.data, 0xff, cmd->info.datalen); 870 cmd->scmd.data_len = 9; 871 } else { 872 if (cmd->info.datalen > SMU_I2C_WRITE_MAX) 873 return -EINVAL; 874 cmd->scmd.data_len = 9 + cmd->info.datalen; 875 } 876 877 DPRINTK("SMU: i2c enqueuing command\n"); 878 DPRINTK("SMU: %s, len=%d bus=%x addr=%x sub0=%x type=%x\n", 879 cmd->read ? "read" : "write", cmd->info.datalen, 880 cmd->info.bus, cmd->info.caddr, 881 cmd->info.subaddr[0], cmd->info.type); 882 883 884 /* Enqueue command in i2c list, and if empty, enqueue also in 885 * main command list 886 */ 887 spin_lock_irqsave(&smu->lock, flags); 888 if (smu->cmd_i2c_cur == NULL) { 889 smu->cmd_i2c_cur = cmd; 890 list_add_tail(&cmd->scmd.link, &smu->cmd_list); 891 if (smu->cmd_cur == NULL) 892 smu_start_cmd(); 893 } else 894 list_add_tail(&cmd->link, &smu->cmd_i2c_list); 895 spin_unlock_irqrestore(&smu->lock, flags); 896 897 return 0; 898 } 899 900 /* 901 * Handling of "partitions" 902 */ 903 904 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len) 905 { 906 DECLARE_COMPLETION_ONSTACK(comp); 907 unsigned int chunk; 908 struct smu_cmd cmd; 909 int rc; 910 u8 params[8]; 911 912 /* We currently use a chunk size of 0xe. We could check the 913 * SMU firmware version and use bigger sizes though 914 */ 915 chunk = 0xe; 916 917 while (len) { 918 unsigned int clen = min(len, chunk); 919 920 cmd.cmd = SMU_CMD_MISC_ee_COMMAND; 921 cmd.data_len = 7; 922 cmd.data_buf = params; 923 cmd.reply_len = chunk; 924 cmd.reply_buf = dest; 925 cmd.done = smu_done_complete; 926 cmd.misc = ∁ 927 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC; 928 params[1] = 0x4; 929 *((u32 *)¶ms[2]) = addr; 930 params[6] = clen; 931 932 rc = smu_queue_cmd(&cmd); 933 if (rc) 934 return rc; 935 wait_for_completion(&comp); 936 if (cmd.status != 0) 937 return rc; 938 if (cmd.reply_len != clen) { 939 printk(KERN_DEBUG "SMU: short read in " 940 "smu_read_datablock, got: %d, want: %d\n", 941 cmd.reply_len, clen); 942 return -EIO; 943 } 944 len -= clen; 945 addr += clen; 946 dest += clen; 947 } 948 return 0; 949 } 950 951 static struct smu_sdbp_header *smu_create_sdb_partition(int id) 952 { 953 DECLARE_COMPLETION_ONSTACK(comp); 954 struct smu_simple_cmd cmd; 955 unsigned int addr, len, tlen; 956 struct smu_sdbp_header *hdr; 957 struct property *prop; 958 959 /* First query the partition info */ 960 DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq); 961 smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2, 962 smu_done_complete, &comp, 963 SMU_CMD_PARTITION_LATEST, id); 964 wait_for_completion(&comp); 965 DPRINTK("SMU: done, status: %d, reply_len: %d\n", 966 cmd.cmd.status, cmd.cmd.reply_len); 967 968 /* Partition doesn't exist (or other error) */ 969 if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6) 970 return NULL; 971 972 /* Fetch address and length from reply */ 973 addr = *((u16 *)cmd.buffer); 974 len = cmd.buffer[3] << 2; 975 /* Calucluate total length to allocate, including the 17 bytes 976 * for "sdb-partition-XX" that we append at the end of the buffer 977 */ 978 tlen = sizeof(struct property) + len + 18; 979 980 prop = kzalloc(tlen, GFP_KERNEL); 981 if (prop == NULL) 982 return NULL; 983 hdr = (struct smu_sdbp_header *)(prop + 1); 984 prop->name = ((char *)prop) + tlen - 18; 985 sprintf(prop->name, "sdb-partition-%02x", id); 986 prop->length = len; 987 prop->value = hdr; 988 prop->next = NULL; 989 990 /* Read the datablock */ 991 if (smu_read_datablock((u8 *)hdr, addr, len)) { 992 printk(KERN_DEBUG "SMU: datablock read failed while reading " 993 "partition %02x !\n", id); 994 goto failure; 995 } 996 997 /* Got it, check a few things and create the property */ 998 if (hdr->id != id) { 999 printk(KERN_DEBUG "SMU: Reading partition %02x and got " 1000 "%02x !\n", id, hdr->id); 1001 goto failure; 1002 } 1003 if (of_add_property(smu->of_node, prop)) { 1004 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x " 1005 "property !\n", id); 1006 goto failure; 1007 } 1008 1009 return hdr; 1010 failure: 1011 kfree(prop); 1012 return NULL; 1013 } 1014 1015 /* Note: Only allowed to return error code in pointers (using ERR_PTR) 1016 * when interruptible is 1 1017 */ 1018 static const struct smu_sdbp_header *__smu_get_sdb_partition(int id, 1019 unsigned int *size, int interruptible) 1020 { 1021 char pname[32]; 1022 const struct smu_sdbp_header *part; 1023 1024 if (!smu) 1025 return NULL; 1026 1027 sprintf(pname, "sdb-partition-%02x", id); 1028 1029 DPRINTK("smu_get_sdb_partition(%02x)\n", id); 1030 1031 if (interruptible) { 1032 int rc; 1033 rc = mutex_lock_interruptible(&smu_part_access); 1034 if (rc) 1035 return ERR_PTR(rc); 1036 } else 1037 mutex_lock(&smu_part_access); 1038 1039 part = of_get_property(smu->of_node, pname, size); 1040 if (part == NULL) { 1041 DPRINTK("trying to extract from SMU ...\n"); 1042 part = smu_create_sdb_partition(id); 1043 if (part != NULL && size) 1044 *size = part->len << 2; 1045 } 1046 mutex_unlock(&smu_part_access); 1047 return part; 1048 } 1049 1050 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size) 1051 { 1052 return __smu_get_sdb_partition(id, size, 0); 1053 } 1054 EXPORT_SYMBOL(smu_get_sdb_partition); 1055 1056 1057 /* 1058 * Userland driver interface 1059 */ 1060 1061 1062 static LIST_HEAD(smu_clist); 1063 static DEFINE_SPINLOCK(smu_clist_lock); 1064 1065 enum smu_file_mode { 1066 smu_file_commands, 1067 smu_file_events, 1068 smu_file_closing 1069 }; 1070 1071 struct smu_private 1072 { 1073 struct list_head list; 1074 enum smu_file_mode mode; 1075 int busy; 1076 struct smu_cmd cmd; 1077 spinlock_t lock; 1078 wait_queue_head_t wait; 1079 u8 buffer[SMU_MAX_DATA]; 1080 }; 1081 1082 1083 static int smu_open(struct inode *inode, struct file *file) 1084 { 1085 struct smu_private *pp; 1086 unsigned long flags; 1087 1088 pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL); 1089 if (!pp) 1090 return -ENOMEM; 1091 spin_lock_init(&pp->lock); 1092 pp->mode = smu_file_commands; 1093 init_waitqueue_head(&pp->wait); 1094 1095 mutex_lock(&smu_mutex); 1096 spin_lock_irqsave(&smu_clist_lock, flags); 1097 list_add(&pp->list, &smu_clist); 1098 spin_unlock_irqrestore(&smu_clist_lock, flags); 1099 file->private_data = pp; 1100 mutex_unlock(&smu_mutex); 1101 1102 return 0; 1103 } 1104 1105 1106 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc) 1107 { 1108 struct smu_private *pp = misc; 1109 1110 wake_up_all(&pp->wait); 1111 } 1112 1113 1114 static ssize_t smu_write(struct file *file, const char __user *buf, 1115 size_t count, loff_t *ppos) 1116 { 1117 struct smu_private *pp = file->private_data; 1118 unsigned long flags; 1119 struct smu_user_cmd_hdr hdr; 1120 int rc = 0; 1121 1122 if (pp->busy) 1123 return -EBUSY; 1124 else if (copy_from_user(&hdr, buf, sizeof(hdr))) 1125 return -EFAULT; 1126 else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) { 1127 pp->mode = smu_file_events; 1128 return 0; 1129 } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) { 1130 const struct smu_sdbp_header *part; 1131 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1); 1132 if (part == NULL) 1133 return -EINVAL; 1134 else if (IS_ERR(part)) 1135 return PTR_ERR(part); 1136 return 0; 1137 } else if (hdr.cmdtype != SMU_CMDTYPE_SMU) 1138 return -EINVAL; 1139 else if (pp->mode != smu_file_commands) 1140 return -EBADFD; 1141 else if (hdr.data_len > SMU_MAX_DATA) 1142 return -EINVAL; 1143 1144 spin_lock_irqsave(&pp->lock, flags); 1145 if (pp->busy) { 1146 spin_unlock_irqrestore(&pp->lock, flags); 1147 return -EBUSY; 1148 } 1149 pp->busy = 1; 1150 pp->cmd.status = 1; 1151 spin_unlock_irqrestore(&pp->lock, flags); 1152 1153 if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) { 1154 pp->busy = 0; 1155 return -EFAULT; 1156 } 1157 1158 pp->cmd.cmd = hdr.cmd; 1159 pp->cmd.data_len = hdr.data_len; 1160 pp->cmd.reply_len = SMU_MAX_DATA; 1161 pp->cmd.data_buf = pp->buffer; 1162 pp->cmd.reply_buf = pp->buffer; 1163 pp->cmd.done = smu_user_cmd_done; 1164 pp->cmd.misc = pp; 1165 rc = smu_queue_cmd(&pp->cmd); 1166 if (rc < 0) 1167 return rc; 1168 return count; 1169 } 1170 1171 1172 static ssize_t smu_read_command(struct file *file, struct smu_private *pp, 1173 char __user *buf, size_t count) 1174 { 1175 DECLARE_WAITQUEUE(wait, current); 1176 struct smu_user_reply_hdr hdr; 1177 unsigned long flags; 1178 int size, rc = 0; 1179 1180 if (!pp->busy) 1181 return 0; 1182 if (count < sizeof(struct smu_user_reply_hdr)) 1183 return -EOVERFLOW; 1184 spin_lock_irqsave(&pp->lock, flags); 1185 if (pp->cmd.status == 1) { 1186 if (file->f_flags & O_NONBLOCK) { 1187 spin_unlock_irqrestore(&pp->lock, flags); 1188 return -EAGAIN; 1189 } 1190 add_wait_queue(&pp->wait, &wait); 1191 for (;;) { 1192 set_current_state(TASK_INTERRUPTIBLE); 1193 rc = 0; 1194 if (pp->cmd.status != 1) 1195 break; 1196 rc = -ERESTARTSYS; 1197 if (signal_pending(current)) 1198 break; 1199 spin_unlock_irqrestore(&pp->lock, flags); 1200 schedule(); 1201 spin_lock_irqsave(&pp->lock, flags); 1202 } 1203 set_current_state(TASK_RUNNING); 1204 remove_wait_queue(&pp->wait, &wait); 1205 } 1206 spin_unlock_irqrestore(&pp->lock, flags); 1207 if (rc) 1208 return rc; 1209 if (pp->cmd.status != 0) 1210 pp->cmd.reply_len = 0; 1211 size = sizeof(hdr) + pp->cmd.reply_len; 1212 if (count < size) 1213 size = count; 1214 rc = size; 1215 hdr.status = pp->cmd.status; 1216 hdr.reply_len = pp->cmd.reply_len; 1217 if (copy_to_user(buf, &hdr, sizeof(hdr))) 1218 return -EFAULT; 1219 size -= sizeof(hdr); 1220 if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size)) 1221 return -EFAULT; 1222 pp->busy = 0; 1223 1224 return rc; 1225 } 1226 1227 1228 static ssize_t smu_read_events(struct file *file, struct smu_private *pp, 1229 char __user *buf, size_t count) 1230 { 1231 /* Not implemented */ 1232 msleep_interruptible(1000); 1233 return 0; 1234 } 1235 1236 1237 static ssize_t smu_read(struct file *file, char __user *buf, 1238 size_t count, loff_t *ppos) 1239 { 1240 struct smu_private *pp = file->private_data; 1241 1242 if (pp->mode == smu_file_commands) 1243 return smu_read_command(file, pp, buf, count); 1244 if (pp->mode == smu_file_events) 1245 return smu_read_events(file, pp, buf, count); 1246 1247 return -EBADFD; 1248 } 1249 1250 static __poll_t smu_fpoll(struct file *file, poll_table *wait) 1251 { 1252 struct smu_private *pp = file->private_data; 1253 __poll_t mask = 0; 1254 unsigned long flags; 1255 1256 if (!pp) 1257 return 0; 1258 1259 if (pp->mode == smu_file_commands) { 1260 poll_wait(file, &pp->wait, wait); 1261 1262 spin_lock_irqsave(&pp->lock, flags); 1263 if (pp->busy && pp->cmd.status != 1) 1264 mask |= EPOLLIN; 1265 spin_unlock_irqrestore(&pp->lock, flags); 1266 } 1267 if (pp->mode == smu_file_events) { 1268 /* Not yet implemented */ 1269 } 1270 return mask; 1271 } 1272 1273 static int smu_release(struct inode *inode, struct file *file) 1274 { 1275 struct smu_private *pp = file->private_data; 1276 unsigned long flags; 1277 unsigned int busy; 1278 1279 if (!pp) 1280 return 0; 1281 1282 file->private_data = NULL; 1283 1284 /* Mark file as closing to avoid races with new request */ 1285 spin_lock_irqsave(&pp->lock, flags); 1286 pp->mode = smu_file_closing; 1287 busy = pp->busy; 1288 1289 /* Wait for any pending request to complete */ 1290 if (busy && pp->cmd.status == 1) { 1291 DECLARE_WAITQUEUE(wait, current); 1292 1293 add_wait_queue(&pp->wait, &wait); 1294 for (;;) { 1295 set_current_state(TASK_UNINTERRUPTIBLE); 1296 if (pp->cmd.status != 1) 1297 break; 1298 spin_unlock_irqrestore(&pp->lock, flags); 1299 schedule(); 1300 spin_lock_irqsave(&pp->lock, flags); 1301 } 1302 set_current_state(TASK_RUNNING); 1303 remove_wait_queue(&pp->wait, &wait); 1304 } 1305 spin_unlock_irqrestore(&pp->lock, flags); 1306 1307 spin_lock_irqsave(&smu_clist_lock, flags); 1308 list_del(&pp->list); 1309 spin_unlock_irqrestore(&smu_clist_lock, flags); 1310 kfree(pp); 1311 1312 return 0; 1313 } 1314 1315 1316 static const struct file_operations smu_device_fops = { 1317 .read = smu_read, 1318 .write = smu_write, 1319 .poll = smu_fpoll, 1320 .open = smu_open, 1321 .release = smu_release, 1322 }; 1323 1324 static struct miscdevice pmu_device = { 1325 MISC_DYNAMIC_MINOR, "smu", &smu_device_fops 1326 }; 1327 1328 static int smu_device_init(void) 1329 { 1330 if (!smu) 1331 return -ENODEV; 1332 if (misc_register(&pmu_device) < 0) 1333 printk(KERN_ERR "via-pmu: cannot register misc device.\n"); 1334 return 0; 1335 } 1336 device_initcall(smu_device_init); 1337