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_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/prom.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         const u32 *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         data = of_get_property(smu->db_node, "reg", NULL);
 519         if (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                 data = of_get_property(smu->msg_node, "reg", NULL);
 539                 if (data == NULL) {
 540                         of_node_put(smu->msg_node);
 541                         smu->msg_node = NULL;
 542                         break;
 543                 }
 544                 smu->msg = *data;
 545                 if (smu->msg < 0x50)
 546                         smu->msg += 0x50;
 547         } while(0);
 548
 549         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 550          * device-tree entry giving the address. Best would probably to use
 551          * an offset for K2 base though, but let's do it that way for now.
 552          */
 553         smu->db_buf = ioremap(0x8000860c, 0x1000);
 554         if (smu->db_buf == NULL) {
 555                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 556                 ret = -ENXIO;
 557                 goto fail_msg_node;
 558         }
 559
 560         /* U3 has an issue with NAP mode when issuing SMU commands */
 561         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 562         if (smu->broken_nap)
 563                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 564
 565         sys_ctrler = SYS_CTRLER_SMU;
 566         return 0;
 567
 568 fail_msg_node:
 569         of_node_put(smu->msg_node);
 570 fail_db_node:
 571         of_node_put(smu->db_node);
 572 fail_bootmem:
 573         memblock_free_ptr(smu, sizeof(struct smu_device));
 574         smu = NULL;
 575 fail_np:
 576         of_node_put(np);
 577         return ret;
 578 }
 579
 580
 581 static int smu_late_init(void)
 582 {
 583         if (!smu)
 584                 return 0;
 585
 586         timer_setup(&smu->i2c_timer, smu_i2c_retry, 0);
 587
 588         if (smu->db_node) {
 589                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 590                 if (!smu->db_irq)
 591                         printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 592                                smu->db_node);
 593         }
 594         if (smu->msg_node) {
 595                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 596                 if (!smu->msg_irq)
 597                         printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 598                                smu->msg_node);
 599         }
 600
 601         /*
 602          * Try to request the interrupts
 603          */
 604
 605         if (smu->db_irq) {
 606                 if (request_irq(smu->db_irq, smu_db_intr,
 607                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 608                         printk(KERN_WARNING "SMU: can't "
 609                                "request interrupt %d\n",
 610                                smu->db_irq);
 611                         smu->db_irq = 0;
 612                 }
 613         }
 614
 615         if (smu->msg_irq) {
 616                 if (request_irq(smu->msg_irq, smu_msg_intr,
 617                                 IRQF_SHARED, "SMU message", smu) < 0) {
 618                         printk(KERN_WARNING "SMU: can't "
 619                                "request interrupt %d\n",
 620                                smu->msg_irq);
 621                         smu->msg_irq = 0;
 622                 }
 623         }
 624
 625         smu_irq_inited = 1;
 626         return 0;
 627 }
 628 /* This has to be before arch_initcall as the low i2c stuff relies on the
 629  * above having been done before we reach arch_initcalls
 630  */
 631 core_initcall(smu_late_init);
 632
 633 /*
 634  * sysfs visibility
 635  */
 636
 637 static void smu_expose_childs(struct work_struct *unused)
 638 {
 639         struct device_node *np;
 640
 641         for_each_child_of_node(smu->of_node, np)
 642                 if (of_device_is_compatible(np, "smu-sensors"))
 643                         of_platform_device_create(np, "smu-sensors",
 644                                                   &smu->of_dev->dev);
 645 }
 646
 647 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 648
 649 static int smu_platform_probe(struct platform_device* dev)
 650 {
 651         if (!smu)
 652                 return -ENODEV;
 653         smu->of_dev = dev;
 654
 655         /*
 656          * Ok, we are matched, now expose all i2c busses. We have to defer
 657          * that unfortunately or it would deadlock inside the device model
 658          */
 659         schedule_work(&smu_expose_childs_work);
 660
 661         return 0;
 662 }
 663
 664 static const struct of_device_id smu_platform_match[] =
 665 {
 666         {
 667                 .type           = "smu",
 668         },
 669         {},
 670 };
 671
 672 static struct platform_driver smu_of_platform_driver =
 673 {
 674         .driver = {
 675                 .name = "smu",
 676                 .of_match_table = smu_platform_match,
 677         },
 678         .probe          = smu_platform_probe,
 679 };
 680
 681 static int __init smu_init_sysfs(void)
 682 {
 683         /*
 684          * For now, we don't power manage machines with an SMU chip,
 685          * I'm a bit too far from figuring out how that works with those
 686          * new chipsets, but that will come back and bite us
 687          */
 688         platform_driver_register(&smu_of_platform_driver);
 689         return 0;
 690 }
 691
 692 device_initcall(smu_init_sysfs);
 693
 694 struct platform_device *smu_get_ofdev(void)
 695 {
 696         if (!smu)
 697                 return NULL;
 698         return smu->of_dev;
 699 }
 700
 701 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 702
 703 /*
 704  * i2c interface
 705  */
 706
 707 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 708 {
 709         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 710         void *misc = cmd->misc;
 711         unsigned long flags;
 712
 713         /* Check for read case */
 714         if (!fail && cmd->read) {
 715                 if (cmd->pdata[0] < 1)
 716                         fail = 1;
 717                 else
 718                         memcpy(cmd->info.data, &cmd->pdata[1],
 719                                cmd->info.datalen);
 720         }
 721
 722         DPRINTK("SMU: completing, success: %d\n", !fail);
 723
 724         /* Update status and mark no pending i2c command with lock
 725          * held so nobody comes in while we dequeue an eventual
 726          * pending next i2c command
 727          */
 728         spin_lock_irqsave(&smu->lock, flags);
 729         smu->cmd_i2c_cur = NULL;
 730         wmb();
 731         cmd->status = fail ? -EIO : 0;
 732
 733         /* Is there another i2c command waiting ? */
 734         if (!list_empty(&smu->cmd_i2c_list)) {
 735                 struct smu_i2c_cmd *newcmd;
 736
 737                 /* Fetch it, new current, remove from list */
 738                 newcmd = list_entry(smu->cmd_i2c_list.next,
 739                                     struct smu_i2c_cmd, link);
 740                 smu->cmd_i2c_cur = newcmd;
 741                 list_del(&cmd->link);
 742
 743                 /* Queue with low level smu */
 744                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 745                 if (smu->cmd_cur == NULL)
 746                         smu_start_cmd();
 747         }
 748         spin_unlock_irqrestore(&smu->lock, flags);
 749
 750         /* Call command completion handler if any */
 751         if (done)
 752                 done(cmd, misc);
 753
 754 }
 755
 756
 757 static void smu_i2c_retry(struct timer_list *unused)
 758 {
 759         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 760
 761         DPRINTK("SMU: i2c failure, requeuing...\n");
 762
 763         /* requeue command simply by resetting reply_len */
 764         cmd->pdata[0] = 0xff;
 765         cmd->scmd.reply_len = sizeof(cmd->pdata);
 766         smu_queue_cmd(&cmd->scmd);
 767 }
 768
 769
 770 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 771 {
 772         struct smu_i2c_cmd      *cmd = misc;
 773         int                     fail = 0;
 774
 775         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 776                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 777
 778         /* Check for possible status */
 779         if (scmd->status < 0)
 780                 fail = 1;
 781         else if (cmd->read) {
 782                 if (cmd->stage == 0)
 783                         fail = cmd->pdata[0] != 0;
 784                 else
 785                         fail = cmd->pdata[0] >= 0x80;
 786         } else {
 787                 fail = cmd->pdata[0] != 0;
 788         }
 789
 790         /* Handle failures by requeuing command, after 5ms interval
 791          */
 792         if (fail && --cmd->retries > 0) {
 793                 DPRINTK("SMU: i2c failure, starting timer...\n");
 794                 BUG_ON(cmd != smu->cmd_i2c_cur);
 795                 if (!smu_irq_inited) {
 796                         mdelay(5);
 797                         smu_i2c_retry(NULL);
 798                         return;
 799                 }
 800                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 801                 return;
 802         }
 803
 804         /* If failure or stage 1, command is complete */
 805         if (fail || cmd->stage != 0) {
 806                 smu_i2c_complete_command(cmd, fail);
 807                 return;
 808         }
 809
 810         DPRINTK("SMU: going to stage 1\n");
 811
 812         /* Ok, initial command complete, now poll status */
 813         scmd->reply_buf = cmd->pdata;
 814         scmd->reply_len = sizeof(cmd->pdata);
 815         scmd->data_buf = cmd->pdata;
 816         scmd->data_len = 1;
 817         cmd->pdata[0] = 0;
 818         cmd->stage = 1;
 819         cmd->retries = 20;
 820         smu_queue_cmd(scmd);
 821 }
 822
 823
 824 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 825 {
 826         unsigned long flags;
 827
 828         if (smu == NULL)
 829                 return -ENODEV;
 830
 831         /* Fill most fields of scmd */
 832         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 833         cmd->scmd.done = smu_i2c_low_completion;
 834         cmd->scmd.misc = cmd;
 835         cmd->scmd.reply_buf = cmd->pdata;
 836         cmd->scmd.reply_len = sizeof(cmd->pdata);
 837         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 838         cmd->scmd.status = 1;
 839         cmd->stage = 0;
 840         cmd->pdata[0] = 0xff;
 841         cmd->retries = 20;
 842         cmd->status = 1;
 843
 844         /* Check transfer type, sanitize some "info" fields
 845          * based on transfer type and do more checking
 846          */
 847         cmd->info.caddr = cmd->info.devaddr;
 848         cmd->read = cmd->info.devaddr & 0x01;
 849         switch(cmd->info.type) {
 850         case SMU_I2C_TRANSFER_SIMPLE:
 851                 memset(&cmd->info.sublen, 0, 4);
 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 = &comp;
 927                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 928                 params[1] = 0x4;
 929                 *((u32 *)&params[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 == 0)
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 == 0)
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 == 0)
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);