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_device.h> 37 #include <linux/of_irq.h> 38 #include <linux/of_platform.h> 39 #include <linux/slab.h> 40 #include <linux/sched/signal.h> 41 42 #include <asm/byteorder.h> 43 #include <asm/io.h> 44 #include <asm/machdep.h> 45 #include <asm/pmac_feature.h> 46 #include <asm/smu.h> 47 #include <asm/sections.h> 48 #include <linux/uaccess.h> 49 50 #define VERSION "0.7" 51 #define AUTHOR "(c) 2005 Benjamin Herrenschmidt, IBM Corp." 52 53 #undef DEBUG_SMU 54 55 #ifdef DEBUG_SMU 56 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0) 57 #else 58 #define DPRINTK(fmt, args...) do { } while (0) 59 #endif 60 61 /* 62 * This is the command buffer passed to the SMU hardware 63 */ 64 #define SMU_MAX_DATA 254 65 66 struct smu_cmd_buf { 67 u8 cmd; 68 u8 length; 69 u8 data[SMU_MAX_DATA]; 70 }; 71 72 struct smu_device { 73 spinlock_t lock; 74 struct device_node *of_node; 75 struct platform_device *of_dev; 76 int doorbell; /* doorbell gpio */ 77 u32 __iomem *db_buf; /* doorbell buffer */ 78 struct device_node *db_node; 79 unsigned int db_irq; 80 int msg; 81 struct device_node *msg_node; 82 unsigned int msg_irq; 83 struct smu_cmd_buf *cmd_buf; /* command buffer virtual */ 84 u32 cmd_buf_abs; /* command buffer absolute */ 85 struct list_head cmd_list; 86 struct smu_cmd *cmd_cur; /* pending command */ 87 int broken_nap; 88 struct list_head cmd_i2c_list; 89 struct smu_i2c_cmd *cmd_i2c_cur; /* pending i2c command */ 90 struct timer_list i2c_timer; 91 }; 92 93 /* 94 * I don't think there will ever be more than one SMU, so 95 * for now, just hard code that 96 */ 97 static DEFINE_MUTEX(smu_mutex); 98 static struct smu_device *smu; 99 static DEFINE_MUTEX(smu_part_access); 100 static int smu_irq_inited; 101 static unsigned long smu_cmdbuf_abs; 102 103 static void smu_i2c_retry(struct timer_list *t); 104 105 /* 106 * SMU driver low level stuff 107 */ 108 109 static void smu_start_cmd(void) 110 { 111 unsigned long faddr, fend; 112 struct smu_cmd *cmd; 113 114 if (list_empty(&smu->cmd_list)) 115 return; 116 117 /* Fetch first command in queue */ 118 cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link); 119 smu->cmd_cur = cmd; 120 list_del(&cmd->link); 121 122 DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd, 123 cmd->data_len); 124 DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf); 125 126 /* Fill the SMU command buffer */ 127 smu->cmd_buf->cmd = cmd->cmd; 128 smu->cmd_buf->length = cmd->data_len; 129 memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len); 130 131 /* Flush command and data to RAM */ 132 faddr = (unsigned long)smu->cmd_buf; 133 fend = faddr + smu->cmd_buf->length + 2; 134 flush_dcache_range(faddr, fend); 135 136 137 /* We also disable NAP mode for the duration of the command 138 * on U3 based machines. 139 * This is slightly racy as it can be written back to 1 by a sysctl 140 * but that never happens in practice. There seem to be an issue with 141 * U3 based machines such as the iMac G5 where napping for the 142 * whole duration of the command prevents the SMU from fetching it 143 * from memory. This might be related to the strange i2c based 144 * mechanism the SMU uses to access memory. 145 */ 146 if (smu->broken_nap) 147 powersave_nap = 0; 148 149 /* This isn't exactly a DMA mapping here, I suspect 150 * the SMU is actually communicating with us via i2c to the 151 * northbridge or the CPU to access RAM. 152 */ 153 writel(smu->cmd_buf_abs, smu->db_buf); 154 155 /* Ring the SMU doorbell */ 156 pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4); 157 } 158 159 160 static irqreturn_t smu_db_intr(int irq, void *arg) 161 { 162 unsigned long flags; 163 struct smu_cmd *cmd; 164 void (*done)(struct smu_cmd *cmd, void *misc) = NULL; 165 void *misc = NULL; 166 u8 gpio; 167 int rc = 0; 168 169 /* SMU completed the command, well, we hope, let's make sure 170 * of it 171 */ 172 spin_lock_irqsave(&smu->lock, flags); 173 174 gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell); 175 if ((gpio & 7) != 7) { 176 spin_unlock_irqrestore(&smu->lock, flags); 177 return IRQ_HANDLED; 178 } 179 180 cmd = smu->cmd_cur; 181 smu->cmd_cur = NULL; 182 if (cmd == NULL) 183 goto bail; 184 185 if (rc == 0) { 186 unsigned long faddr; 187 int reply_len; 188 u8 ack; 189 190 /* CPU might have brought back the cache line, so we need 191 * to flush again before peeking at the SMU response. We 192 * flush the entire buffer for now as we haven't read the 193 * reply length (it's only 2 cache lines anyway) 194 */ 195 faddr = (unsigned long)smu->cmd_buf; 196 flush_dcache_range(faddr, faddr + 256); 197 198 /* Now check ack */ 199 ack = (~cmd->cmd) & 0xff; 200 if (ack != smu->cmd_buf->cmd) { 201 DPRINTK("SMU: incorrect ack, want %x got %x\n", 202 ack, smu->cmd_buf->cmd); 203 rc = -EIO; 204 } 205 reply_len = rc == 0 ? smu->cmd_buf->length : 0; 206 DPRINTK("SMU: reply len: %d\n", reply_len); 207 if (reply_len > cmd->reply_len) { 208 printk(KERN_WARNING "SMU: reply buffer too small," 209 "got %d bytes for a %d bytes buffer\n", 210 reply_len, cmd->reply_len); 211 reply_len = cmd->reply_len; 212 } 213 cmd->reply_len = reply_len; 214 if (cmd->reply_buf && reply_len) 215 memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len); 216 } 217 218 /* Now complete the command. Write status last in order as we lost 219 * ownership of the command structure as soon as it's no longer -1 220 */ 221 done = cmd->done; 222 misc = cmd->misc; 223 mb(); 224 cmd->status = rc; 225 226 /* Re-enable NAP mode */ 227 if (smu->broken_nap) 228 powersave_nap = 1; 229 bail: 230 /* Start next command if any */ 231 smu_start_cmd(); 232 spin_unlock_irqrestore(&smu->lock, flags); 233 234 /* Call command completion handler if any */ 235 if (done) 236 done(cmd, misc); 237 238 /* It's an edge interrupt, nothing to do */ 239 return IRQ_HANDLED; 240 } 241 242 243 static irqreturn_t smu_msg_intr(int irq, void *arg) 244 { 245 /* I don't quite know what to do with this one, we seem to never 246 * receive it, so I suspect we have to arm it someway in the SMU 247 * to start getting events that way. 248 */ 249 250 printk(KERN_INFO "SMU: message interrupt !\n"); 251 252 /* It's an edge interrupt, nothing to do */ 253 return IRQ_HANDLED; 254 } 255 256 257 /* 258 * Queued command management. 259 * 260 */ 261 262 int smu_queue_cmd(struct smu_cmd *cmd) 263 { 264 unsigned long flags; 265 266 if (smu == NULL) 267 return -ENODEV; 268 if (cmd->data_len > SMU_MAX_DATA || 269 cmd->reply_len > SMU_MAX_DATA) 270 return -EINVAL; 271 272 cmd->status = 1; 273 spin_lock_irqsave(&smu->lock, flags); 274 list_add_tail(&cmd->link, &smu->cmd_list); 275 if (smu->cmd_cur == NULL) 276 smu_start_cmd(); 277 spin_unlock_irqrestore(&smu->lock, flags); 278 279 /* Workaround for early calls when irq isn't available */ 280 if (!smu_irq_inited || !smu->db_irq) 281 smu_spinwait_cmd(cmd); 282 283 return 0; 284 } 285 EXPORT_SYMBOL(smu_queue_cmd); 286 287 288 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command, 289 unsigned int data_len, 290 void (*done)(struct smu_cmd *cmd, void *misc), 291 void *misc, ...) 292 { 293 struct smu_cmd *cmd = &scmd->cmd; 294 va_list list; 295 int i; 296 297 if (data_len > sizeof(scmd->buffer)) 298 return -EINVAL; 299 300 memset(scmd, 0, sizeof(*scmd)); 301 cmd->cmd = command; 302 cmd->data_len = data_len; 303 cmd->data_buf = scmd->buffer; 304 cmd->reply_len = sizeof(scmd->buffer); 305 cmd->reply_buf = scmd->buffer; 306 cmd->done = done; 307 cmd->misc = misc; 308 309 va_start(list, misc); 310 for (i = 0; i < data_len; ++i) 311 scmd->buffer[i] = (u8)va_arg(list, int); 312 va_end(list); 313 314 return smu_queue_cmd(cmd); 315 } 316 EXPORT_SYMBOL(smu_queue_simple); 317 318 319 void smu_poll(void) 320 { 321 u8 gpio; 322 323 if (smu == NULL) 324 return; 325 326 gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell); 327 if ((gpio & 7) == 7) 328 smu_db_intr(smu->db_irq, smu); 329 } 330 EXPORT_SYMBOL(smu_poll); 331 332 333 void smu_done_complete(struct smu_cmd *cmd, void *misc) 334 { 335 struct completion *comp = misc; 336 337 complete(comp); 338 } 339 EXPORT_SYMBOL(smu_done_complete); 340 341 342 void smu_spinwait_cmd(struct smu_cmd *cmd) 343 { 344 while(cmd->status == 1) 345 smu_poll(); 346 } 347 EXPORT_SYMBOL(smu_spinwait_cmd); 348 349 350 /* RTC low level commands */ 351 static inline int bcd2hex (int n) 352 { 353 return (((n & 0xf0) >> 4) * 10) + (n & 0xf); 354 } 355 356 357 static inline int hex2bcd (int n) 358 { 359 return ((n / 10) << 4) + (n % 10); 360 } 361 362 363 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf, 364 struct rtc_time *time) 365 { 366 cmd_buf->cmd = 0x8e; 367 cmd_buf->length = 8; 368 cmd_buf->data[0] = 0x80; 369 cmd_buf->data[1] = hex2bcd(time->tm_sec); 370 cmd_buf->data[2] = hex2bcd(time->tm_min); 371 cmd_buf->data[3] = hex2bcd(time->tm_hour); 372 cmd_buf->data[4] = time->tm_wday; 373 cmd_buf->data[5] = hex2bcd(time->tm_mday); 374 cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1; 375 cmd_buf->data[7] = hex2bcd(time->tm_year - 100); 376 } 377 378 379 int smu_get_rtc_time(struct rtc_time *time, int spinwait) 380 { 381 struct smu_simple_cmd cmd; 382 int rc; 383 384 if (smu == NULL) 385 return -ENODEV; 386 387 memset(time, 0, sizeof(struct rtc_time)); 388 rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL, 389 SMU_CMD_RTC_GET_DATETIME); 390 if (rc) 391 return rc; 392 smu_spinwait_simple(&cmd); 393 394 time->tm_sec = bcd2hex(cmd.buffer[0]); 395 time->tm_min = bcd2hex(cmd.buffer[1]); 396 time->tm_hour = bcd2hex(cmd.buffer[2]); 397 time->tm_wday = bcd2hex(cmd.buffer[3]); 398 time->tm_mday = bcd2hex(cmd.buffer[4]); 399 time->tm_mon = bcd2hex(cmd.buffer[5]) - 1; 400 time->tm_year = bcd2hex(cmd.buffer[6]) + 100; 401 402 return 0; 403 } 404 405 406 int smu_set_rtc_time(struct rtc_time *time, int spinwait) 407 { 408 struct smu_simple_cmd cmd; 409 int rc; 410 411 if (smu == NULL) 412 return -ENODEV; 413 414 rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL, 415 SMU_CMD_RTC_SET_DATETIME, 416 hex2bcd(time->tm_sec), 417 hex2bcd(time->tm_min), 418 hex2bcd(time->tm_hour), 419 time->tm_wday, 420 hex2bcd(time->tm_mday), 421 hex2bcd(time->tm_mon) + 1, 422 hex2bcd(time->tm_year - 100)); 423 if (rc) 424 return rc; 425 smu_spinwait_simple(&cmd); 426 427 return 0; 428 } 429 430 431 void smu_shutdown(void) 432 { 433 struct smu_simple_cmd cmd; 434 435 if (smu == NULL) 436 return; 437 438 if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL, 439 'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0)) 440 return; 441 smu_spinwait_simple(&cmd); 442 for (;;) 443 ; 444 } 445 446 447 void smu_restart(void) 448 { 449 struct smu_simple_cmd cmd; 450 451 if (smu == NULL) 452 return; 453 454 if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL, 455 'R', 'E', 'S', 'T', 'A', 'R', 'T', 0)) 456 return; 457 smu_spinwait_simple(&cmd); 458 for (;;) 459 ; 460 } 461 462 463 int smu_present(void) 464 { 465 return smu != NULL; 466 } 467 EXPORT_SYMBOL(smu_present); 468 469 470 int __init smu_init (void) 471 { 472 struct device_node *np; 473 const u32 *data; 474 int ret = 0; 475 476 np = of_find_node_by_type(NULL, "smu"); 477 if (np == NULL) 478 return -ENODEV; 479 480 printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR); 481 482 /* 483 * SMU based G5s need some memory below 2Gb. Thankfully this is 484 * called at a time where memblock is still available. 485 */ 486 smu_cmdbuf_abs = memblock_phys_alloc_range(4096, 4096, 0, 0x80000000UL); 487 if (smu_cmdbuf_abs == 0) { 488 printk(KERN_ERR "SMU: Command buffer allocation failed !\n"); 489 ret = -EINVAL; 490 goto fail_np; 491 } 492 493 smu = memblock_alloc(sizeof(struct smu_device), SMP_CACHE_BYTES); 494 if (!smu) 495 panic("%s: Failed to allocate %zu bytes\n", __func__, 496 sizeof(struct smu_device)); 497 498 spin_lock_init(&smu->lock); 499 INIT_LIST_HEAD(&smu->cmd_list); 500 INIT_LIST_HEAD(&smu->cmd_i2c_list); 501 smu->of_node = np; 502 smu->db_irq = 0; 503 smu->msg_irq = 0; 504 505 /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a 506 * 32 bits value safely 507 */ 508 smu->cmd_buf_abs = (u32)smu_cmdbuf_abs; 509 smu->cmd_buf = __va(smu_cmdbuf_abs); 510 511 smu->db_node = of_find_node_by_name(NULL, "smu-doorbell"); 512 if (smu->db_node == NULL) { 513 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n"); 514 ret = -ENXIO; 515 goto fail_bootmem; 516 } 517 data = of_get_property(smu->db_node, "reg", NULL); 518 if (data == NULL) { 519 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n"); 520 ret = -ENXIO; 521 goto fail_db_node; 522 } 523 524 /* Current setup has one doorbell GPIO that does both doorbell 525 * and ack. GPIOs are at 0x50, best would be to find that out 526 * in the device-tree though. 527 */ 528 smu->doorbell = *data; 529 if (smu->doorbell < 0x50) 530 smu->doorbell += 0x50; 531 532 /* Now look for the smu-interrupt GPIO */ 533 do { 534 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt"); 535 if (smu->msg_node == NULL) 536 break; 537 data = of_get_property(smu->msg_node, "reg", NULL); 538 if (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 .llseek = no_llseek, 1318 .read = smu_read, 1319 .write = smu_write, 1320 .poll = smu_fpoll, 1321 .open = smu_open, 1322 .release = smu_release, 1323 }; 1324 1325 static struct miscdevice pmu_device = { 1326 MISC_DYNAMIC_MINOR, "smu", &smu_device_fops 1327 }; 1328 1329 static int smu_device_init(void) 1330 { 1331 if (!smu) 1332 return -ENODEV; 1333 if (misc_register(&pmu_device) < 0) 1334 printk(KERN_ERR "via-pmu: cannot register misc device.\n"); 1335 return 0; 1336 } 1337 device_initcall(smu_device_init); 1338