drivers/macintosh/smu.c

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