drivers/macintosh/smu.c

   1 /*
   2  * PowerMac G5 SMU driver
   3  *
   4  * Copyright 2004 J. Mayer <l_indien@magic.fr>
   5  * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   6  *
   7  * Released under the term of the GNU GPL v2.
   8  */
   9
  10 /*
  11  * TODO:
  12  *  - maybe add timeout to commands ?
  13  *  - blocking version of time functions
  14  *  - polling version of i2c commands (including timer that works with
  15  *    interrutps off)
  16  *  - maybe avoid some data copies with i2c by directly using the smu cmd
  17  *    buffer and a lower level internal interface
  18  *  - understand SMU -> CPU events and implement reception of them via
  19  *    the userland interface
  20  */
  21
  22 #include <linux/config.h>
  23 #include <linux/types.h>
  24 #include <linux/kernel.h>
  25 #include <linux/device.h>
  26 #include <linux/dmapool.h>
  27 #include <linux/bootmem.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/highmem.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/rtc.h>
  33 #include <linux/completion.h>
  34 #include <linux/miscdevice.h>
  35 #include <linux/delay.h>
  36 #include <linux/sysdev.h>
  37 #include <linux/poll.h>
  38 #include <linux/mutex.h>
  39
  40 #include <asm/byteorder.h>
  41 #include <asm/io.h>
  42 #include <asm/prom.h>
  43 #include <asm/machdep.h>
  44 #include <asm/pmac_feature.h>
  45 #include <asm/smu.h>
  46 #include <asm/sections.h>
  47 #include <asm/abs_addr.h>
  48 #include <asm/uaccess.h>
  49 #include <asm/of_device.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 of_device        *of_dev;
  77         int                     doorbell;       /* doorbell gpio */
  78         u32 __iomem             *db_buf;        /* doorbell buffer */
  79         int                     db_irq;
  80         int                     msg;
  81         int                     msg_irq;
  82         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  83         u32                     cmd_buf_abs;    /* command buffer absolute */
  84         struct list_head        cmd_list;
  85         struct smu_cmd          *cmd_cur;       /* pending command */
  86         struct list_head        cmd_i2c_list;
  87         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  88         struct timer_list       i2c_timer;
  89 };
  90
  91 /*
  92  * I don't think there will ever be more than one SMU, so
  93  * for now, just hard code that
  94  */
  95 static struct smu_device        *smu;
  96 static DEFINE_MUTEX(smu_part_access);
  97
  98 static void smu_i2c_retry(unsigned long data);
  99
 100 /*
 101  * SMU driver low level stuff
 102  */
 103
 104 static void smu_start_cmd(void)
 105 {
 106         unsigned long faddr, fend;
 107         struct smu_cmd *cmd;
 108
 109         if (list_empty(&smu->cmd_list))
 110                 return;
 111
 112         /* Fetch first command in queue */
 113         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 114         smu->cmd_cur = cmd;
 115         list_del(&cmd->link);
 116
 117         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 118                 cmd->data_len);
 119         DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 120                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 121                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 122                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 123                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 124
 125         /* Fill the SMU command buffer */
 126         smu->cmd_buf->cmd = cmd->cmd;
 127         smu->cmd_buf->length = cmd->data_len;
 128         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 129
 130         /* Flush command and data to RAM */
 131         faddr = (unsigned long)smu->cmd_buf;
 132         fend = faddr + smu->cmd_buf->length + 2;
 133         flush_inval_dcache_range(faddr, fend);
 134
 135         /* This isn't exactly a DMA mapping here, I suspect
 136          * the SMU is actually communicating with us via i2c to the
 137          * northbridge or the CPU to access RAM.
 138          */
 139         writel(smu->cmd_buf_abs, smu->db_buf);
 140
 141         /* Ring the SMU doorbell */
 142         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 143 }
 144
 145
 146 static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs)
 147 {
 148         unsigned long flags;
 149         struct smu_cmd *cmd;
 150         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 151         void *misc = NULL;
 152         u8 gpio;
 153         int rc = 0;
 154
 155         /* SMU completed the command, well, we hope, let's make sure
 156          * of it
 157          */
 158         spin_lock_irqsave(&smu->lock, flags);
 159
 160         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 161         if ((gpio & 7) != 7) {
 162                 spin_unlock_irqrestore(&smu->lock, flags);
 163                 return IRQ_HANDLED;
 164         }
 165
 166         cmd = smu->cmd_cur;
 167         smu->cmd_cur = NULL;
 168         if (cmd == NULL)
 169                 goto bail;
 170
 171         if (rc == 0) {
 172                 unsigned long faddr;
 173                 int reply_len;
 174                 u8 ack;
 175
 176                 /* CPU might have brought back the cache line, so we need
 177                  * to flush again before peeking at the SMU response. We
 178                  * flush the entire buffer for now as we haven't read the
 179                  * reply lenght (it's only 2 cache lines anyway)
 180                  */
 181                 faddr = (unsigned long)smu->cmd_buf;
 182                 flush_inval_dcache_range(faddr, faddr + 256);
 183
 184                 /* Now check ack */
 185                 ack = (~cmd->cmd) & 0xff;
 186                 if (ack != smu->cmd_buf->cmd) {
 187                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 188                                 ack, smu->cmd_buf->cmd);
 189                         rc = -EIO;
 190                 }
 191                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 192                 DPRINTK("SMU: reply len: %d\n", reply_len);
 193                 if (reply_len > cmd->reply_len) {
 194                         printk(KERN_WARNING "SMU: reply buffer too small,"
 195                                "got %d bytes for a %d bytes buffer\n",
 196                                reply_len, cmd->reply_len);
 197                         reply_len = cmd->reply_len;
 198                 }
 199                 cmd->reply_len = reply_len;
 200                 if (cmd->reply_buf && reply_len)
 201                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 202         }
 203
 204         /* Now complete the command. Write status last in order as we lost
 205          * ownership of the command structure as soon as it's no longer -1
 206          */
 207         done = cmd->done;
 208         misc = cmd->misc;
 209         mb();
 210         cmd->status = rc;
 211  bail:
 212         /* Start next command if any */
 213         smu_start_cmd();
 214         spin_unlock_irqrestore(&smu->lock, flags);
 215
 216         /* Call command completion handler if any */
 217         if (done)
 218                 done(cmd, misc);
 219
 220         /* It's an edge interrupt, nothing to do */
 221         return IRQ_HANDLED;
 222 }
 223
 224
 225 static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
 226 {
 227         /* I don't quite know what to do with this one, we seem to never
 228          * receive it, so I suspect we have to arm it someway in the SMU
 229          * to start getting events that way.
 230          */
 231
 232         printk(KERN_INFO "SMU: message interrupt !\n");
 233
 234         /* It's an edge interrupt, nothing to do */
 235         return IRQ_HANDLED;
 236 }
 237
 238
 239 /*
 240  * Queued command management.
 241  *
 242  */
 243
 244 int smu_queue_cmd(struct smu_cmd *cmd)
 245 {
 246         unsigned long flags;
 247
 248         if (smu == NULL)
 249                 return -ENODEV;
 250         if (cmd->data_len > SMU_MAX_DATA ||
 251             cmd->reply_len > SMU_MAX_DATA)
 252                 return -EINVAL;
 253
 254         cmd->status = 1;
 255         spin_lock_irqsave(&smu->lock, flags);
 256         list_add_tail(&cmd->link, &smu->cmd_list);
 257         if (smu->cmd_cur == NULL)
 258                 smu_start_cmd();
 259         spin_unlock_irqrestore(&smu->lock, flags);
 260
 261         return 0;
 262 }
 263 EXPORT_SYMBOL(smu_queue_cmd);
 264
 265
 266 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 267                      unsigned int data_len,
 268                      void (*done)(struct smu_cmd *cmd, void *misc),
 269                      void *misc, ...)
 270 {
 271         struct smu_cmd *cmd = &scmd->cmd;
 272         va_list list;
 273         int i;
 274
 275         if (data_len > sizeof(scmd->buffer))
 276                 return -EINVAL;
 277
 278         memset(scmd, 0, sizeof(*scmd));
 279         cmd->cmd = command;
 280         cmd->data_len = data_len;
 281         cmd->data_buf = scmd->buffer;
 282         cmd->reply_len = sizeof(scmd->buffer);
 283         cmd->reply_buf = scmd->buffer;
 284         cmd->done = done;
 285         cmd->misc = misc;
 286
 287         va_start(list, misc);
 288         for (i = 0; i < data_len; ++i)
 289                 scmd->buffer[i] = (u8)va_arg(list, int);
 290         va_end(list);
 291
 292         return smu_queue_cmd(cmd);
 293 }
 294 EXPORT_SYMBOL(smu_queue_simple);
 295
 296
 297 void smu_poll(void)
 298 {
 299         u8 gpio;
 300
 301         if (smu == NULL)
 302                 return;
 303
 304         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 305         if ((gpio & 7) == 7)
 306                 smu_db_intr(smu->db_irq, smu, NULL);
 307 }
 308 EXPORT_SYMBOL(smu_poll);
 309
 310
 311 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 312 {
 313         struct completion *comp = misc;
 314
 315         complete(comp);
 316 }
 317 EXPORT_SYMBOL(smu_done_complete);
 318
 319
 320 void smu_spinwait_cmd(struct smu_cmd *cmd)
 321 {
 322         while(cmd->status == 1)
 323                 smu_poll();
 324 }
 325 EXPORT_SYMBOL(smu_spinwait_cmd);
 326
 327
 328 /* RTC low level commands */
 329 static inline int bcd2hex (int n)
 330 {
 331         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 332 }
 333
 334
 335 static inline int hex2bcd (int n)
 336 {
 337         return ((n / 10) << 4) + (n % 10);
 338 }
 339
 340
 341 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 342                                         struct rtc_time *time)
 343 {
 344         cmd_buf->cmd = 0x8e;
 345         cmd_buf->length = 8;
 346         cmd_buf->data[0] = 0x80;
 347         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 348         cmd_buf->data[2] = hex2bcd(time->tm_min);
 349         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 350         cmd_buf->data[4] = time->tm_wday;
 351         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 352         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 353         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 354 }
 355
 356
 357 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 358 {
 359         struct smu_simple_cmd cmd;
 360         int rc;
 361
 362         if (smu == NULL)
 363                 return -ENODEV;
 364
 365         memset(time, 0, sizeof(struct rtc_time));
 366         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 367                               SMU_CMD_RTC_GET_DATETIME);
 368         if (rc)
 369                 return rc;
 370         smu_spinwait_simple(&cmd);
 371
 372         time->tm_sec = bcd2hex(cmd.buffer[0]);
 373         time->tm_min = bcd2hex(cmd.buffer[1]);
 374         time->tm_hour = bcd2hex(cmd.buffer[2]);
 375         time->tm_wday = bcd2hex(cmd.buffer[3]);
 376         time->tm_mday = bcd2hex(cmd.buffer[4]);
 377         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 378         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 379
 380         return 0;
 381 }
 382
 383
 384 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 385 {
 386         struct smu_simple_cmd cmd;
 387         int rc;
 388
 389         if (smu == NULL)
 390                 return -ENODEV;
 391
 392         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 393                               SMU_CMD_RTC_SET_DATETIME,
 394                               hex2bcd(time->tm_sec),
 395                               hex2bcd(time->tm_min),
 396                               hex2bcd(time->tm_hour),
 397                               time->tm_wday,
 398                               hex2bcd(time->tm_mday),
 399                               hex2bcd(time->tm_mon) + 1,
 400                               hex2bcd(time->tm_year - 100));
 401         if (rc)
 402                 return rc;
 403         smu_spinwait_simple(&cmd);
 404
 405         return 0;
 406 }
 407
 408
 409 void smu_shutdown(void)
 410 {
 411         struct smu_simple_cmd cmd;
 412
 413         if (smu == NULL)
 414                 return;
 415
 416         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 417                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 418                 return;
 419         smu_spinwait_simple(&cmd);
 420         for (;;)
 421                 ;
 422 }
 423
 424
 425 void smu_restart(void)
 426 {
 427         struct smu_simple_cmd cmd;
 428
 429         if (smu == NULL)
 430                 return;
 431
 432         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 433                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 434                 return;
 435         smu_spinwait_simple(&cmd);
 436         for (;;)
 437                 ;
 438 }
 439
 440
 441 int smu_present(void)
 442 {
 443         return smu != NULL;
 444 }
 445 EXPORT_SYMBOL(smu_present);
 446
 447
 448 int __init smu_init (void)
 449 {
 450         struct device_node *np;
 451         u32 *data;
 452
 453         np = of_find_node_by_type(NULL, "smu");
 454         if (np == NULL)
 455                 return -ENODEV;
 456
 457         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
 458
 459         if (smu_cmdbuf_abs == 0) {
 460                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 461                 return -EINVAL;
 462         }
 463
 464         smu = alloc_bootmem(sizeof(struct smu_device));
 465         if (smu == NULL)
 466                 return -ENOMEM;
 467         memset(smu, 0, sizeof(*smu));
 468
 469         spin_lock_init(&smu->lock);
 470         INIT_LIST_HEAD(&smu->cmd_list);
 471         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 472         smu->of_node = np;
 473         smu->db_irq = NO_IRQ;
 474         smu->msg_irq = NO_IRQ;
 475
 476         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 477          * 32 bits value safely
 478          */
 479         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 480         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 481
 482         np = of_find_node_by_name(NULL, "smu-doorbell");
 483         if (np == NULL) {
 484                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 485                 goto fail;
 486         }
 487         data = (u32 *)get_property(np, "reg", NULL);
 488         if (data == NULL) {
 489                 of_node_put(np);
 490                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 491                 goto fail;
 492         }
 493
 494         /* Current setup has one doorbell GPIO that does both doorbell
 495          * and ack. GPIOs are at 0x50, best would be to find that out
 496          * in the device-tree though.
 497          */
 498         smu->doorbell = *data;
 499         if (smu->doorbell < 0x50)
 500                 smu->doorbell += 0x50;
 501         if (np->n_intrs > 0)
 502                 smu->db_irq = np->intrs[0].line;
 503
 504         of_node_put(np);
 505
 506         /* Now look for the smu-interrupt GPIO */
 507         do {
 508                 np = of_find_node_by_name(NULL, "smu-interrupt");
 509                 if (np == NULL)
 510                         break;
 511                 data = (u32 *)get_property(np, "reg", NULL);
 512                 if (data == NULL) {
 513                         of_node_put(np);
 514                         break;
 515                 }
 516                 smu->msg = *data;
 517                 if (smu->msg < 0x50)
 518                         smu->msg += 0x50;
 519                 if (np->n_intrs > 0)
 520                         smu->msg_irq = np->intrs[0].line;
 521                 of_node_put(np);
 522         } while(0);
 523
 524         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 525          * device-tree entry giving the address. Best would probably to use
 526          * an offset for K2 base though, but let's do it that way for now.
 527          */
 528         smu->db_buf = ioremap(0x8000860c, 0x1000);
 529         if (smu->db_buf == NULL) {
 530                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 531                 goto fail;
 532         }
 533
 534         sys_ctrler = SYS_CTRLER_SMU;
 535         return 0;
 536
 537  fail:
 538         smu = NULL;
 539         return -ENXIO;
 540
 541 }
 542
 543
 544 static int smu_late_init(void)
 545 {
 546         if (!smu)
 547                 return 0;
 548
 549         init_timer(&smu->i2c_timer);
 550         smu->i2c_timer.function = smu_i2c_retry;
 551         smu->i2c_timer.data = (unsigned long)smu;
 552
 553         /*
 554          * Try to request the interrupts
 555          */
 556
 557         if (smu->db_irq != NO_IRQ) {
 558                 if (request_irq(smu->db_irq, smu_db_intr,
 559                                 SA_SHIRQ, "SMU doorbell", smu) < 0) {
 560                         printk(KERN_WARNING "SMU: can't "
 561                                "request interrupt %d\n",
 562                                smu->db_irq);
 563                         smu->db_irq = NO_IRQ;
 564                 }
 565         }
 566
 567         if (smu->msg_irq != NO_IRQ) {
 568                 if (request_irq(smu->msg_irq, smu_msg_intr,
 569                                 SA_SHIRQ, "SMU message", smu) < 0) {
 570                         printk(KERN_WARNING "SMU: can't "
 571                                "request interrupt %d\n",
 572                                smu->msg_irq);
 573                         smu->msg_irq = NO_IRQ;
 574                 }
 575         }
 576
 577         return 0;
 578 }
 579 /* This has to be before arch_initcall as the low i2c stuff relies on the
 580  * above having been done before we reach arch_initcalls
 581  */
 582 core_initcall(smu_late_init);
 583
 584 /*
 585  * sysfs visibility
 586  */
 587
 588 static void smu_expose_childs(void *unused)
 589 {
 590         struct device_node *np;
 591
 592         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 593                 if (device_is_compatible(np, "smu-sensors"))
 594                         of_platform_device_create(np, "smu-sensors",
 595                                                   &smu->of_dev->dev);
 596 }
 597
 598 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
 599
 600 static int smu_platform_probe(struct of_device* dev,
 601                               const struct of_device_id *match)
 602 {
 603         if (!smu)
 604                 return -ENODEV;
 605         smu->of_dev = dev;
 606
 607         /*
 608          * Ok, we are matched, now expose all i2c busses. We have to defer
 609          * that unfortunately or it would deadlock inside the device model
 610          */
 611         schedule_work(&smu_expose_childs_work);
 612
 613         return 0;
 614 }
 615
 616 static struct of_device_id smu_platform_match[] =
 617 {
 618         {
 619                 .type           = "smu",
 620         },
 621         {},
 622 };
 623
 624 static struct of_platform_driver smu_of_platform_driver =
 625 {
 626         .name           = "smu",
 627         .match_table    = smu_platform_match,
 628         .probe          = smu_platform_probe,
 629 };
 630
 631 static int __init smu_init_sysfs(void)
 632 {
 633         /*
 634          * Due to sysfs bogosity, a sysdev is not a real device, so
 635          * we should in fact create both if we want sysdev semantics
 636          * for power management.
 637          * For now, we don't power manage machines with an SMU chip,
 638          * I'm a bit too far from figuring out how that works with those
 639          * new chipsets, but that will come back and bite us
 640          */
 641         of_register_driver(&smu_of_platform_driver);
 642         return 0;
 643 }
 644
 645 device_initcall(smu_init_sysfs);
 646
 647 struct of_device *smu_get_ofdev(void)
 648 {
 649         if (!smu)
 650                 return NULL;
 651         return smu->of_dev;
 652 }
 653
 654 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 655
 656 /*
 657  * i2c interface
 658  */
 659
 660 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 661 {
 662         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 663         void *misc = cmd->misc;
 664         unsigned long flags;
 665
 666         /* Check for read case */
 667         if (!fail && cmd->read) {
 668                 if (cmd->pdata[0] < 1)
 669                         fail = 1;
 670                 else
 671                         memcpy(cmd->info.data, &cmd->pdata[1],
 672                                cmd->info.datalen);
 673         }
 674
 675         DPRINTK("SMU: completing, success: %d\n", !fail);
 676
 677         /* Update status and mark no pending i2c command with lock
 678          * held so nobody comes in while we dequeue an eventual
 679          * pending next i2c command
 680          */
 681         spin_lock_irqsave(&smu->lock, flags);
 682         smu->cmd_i2c_cur = NULL;
 683         wmb();
 684         cmd->status = fail ? -EIO : 0;
 685
 686         /* Is there another i2c command waiting ? */
 687         if (!list_empty(&smu->cmd_i2c_list)) {
 688                 struct smu_i2c_cmd *newcmd;
 689
 690                 /* Fetch it, new current, remove from list */
 691                 newcmd = list_entry(smu->cmd_i2c_list.next,
 692                                     struct smu_i2c_cmd, link);
 693                 smu->cmd_i2c_cur = newcmd;
 694                 list_del(&cmd->link);
 695
 696                 /* Queue with low level smu */
 697                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 698                 if (smu->cmd_cur == NULL)
 699                         smu_start_cmd();
 700         }
 701         spin_unlock_irqrestore(&smu->lock, flags);
 702
 703         /* Call command completion handler if any */
 704         if (done)
 705                 done(cmd, misc);
 706
 707 }
 708
 709
 710 static void smu_i2c_retry(unsigned long data)
 711 {
 712         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 713
 714         DPRINTK("SMU: i2c failure, requeuing...\n");
 715
 716         /* requeue command simply by resetting reply_len */
 717         cmd->pdata[0] = 0xff;
 718         cmd->scmd.reply_len = sizeof(cmd->pdata);
 719         smu_queue_cmd(&cmd->scmd);
 720 }
 721
 722
 723 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 724 {
 725         struct smu_i2c_cmd      *cmd = misc;
 726         int                     fail = 0;
 727
 728         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 729                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 730
 731         /* Check for possible status */
 732         if (scmd->status < 0)
 733                 fail = 1;
 734         else if (cmd->read) {
 735                 if (cmd->stage == 0)
 736                         fail = cmd->pdata[0] != 0;
 737                 else
 738                         fail = cmd->pdata[0] >= 0x80;
 739         } else {
 740                 fail = cmd->pdata[0] != 0;
 741         }
 742
 743         /* Handle failures by requeuing command, after 5ms interval
 744          */
 745         if (fail && --cmd->retries > 0) {
 746                 DPRINTK("SMU: i2c failure, starting timer...\n");
 747                 BUG_ON(cmd != smu->cmd_i2c_cur);
 748                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 749                 return;
 750         }
 751
 752         /* If failure or stage 1, command is complete */
 753         if (fail || cmd->stage != 0) {
 754                 smu_i2c_complete_command(cmd, fail);
 755                 return;
 756         }
 757
 758         DPRINTK("SMU: going to stage 1\n");
 759
 760         /* Ok, initial command complete, now poll status */
 761         scmd->reply_buf = cmd->pdata;
 762         scmd->reply_len = sizeof(cmd->pdata);
 763         scmd->data_buf = cmd->pdata;
 764         scmd->data_len = 1;
 765         cmd->pdata[0] = 0;
 766         cmd->stage = 1;
 767         cmd->retries = 20;
 768         smu_queue_cmd(scmd);
 769 }
 770
 771
 772 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 773 {
 774         unsigned long flags;
 775
 776         if (smu == NULL)
 777                 return -ENODEV;
 778
 779         /* Fill most fields of scmd */
 780         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 781         cmd->scmd.done = smu_i2c_low_completion;
 782         cmd->scmd.misc = cmd;
 783         cmd->scmd.reply_buf = cmd->pdata;
 784         cmd->scmd.reply_len = sizeof(cmd->pdata);
 785         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 786         cmd->scmd.status = 1;
 787         cmd->stage = 0;
 788         cmd->pdata[0] = 0xff;
 789         cmd->retries = 20;
 790         cmd->status = 1;
 791
 792         /* Check transfer type, sanitize some "info" fields
 793          * based on transfer type and do more checking
 794          */
 795         cmd->info.caddr = cmd->info.devaddr;
 796         cmd->read = cmd->info.devaddr & 0x01;
 797         switch(cmd->info.type) {
 798         case SMU_I2C_TRANSFER_SIMPLE:
 799                 memset(&cmd->info.sublen, 0, 4);
 800                 break;
 801         case SMU_I2C_TRANSFER_COMBINED:
 802                 cmd->info.devaddr &= 0xfe;
 803         case SMU_I2C_TRANSFER_STDSUB:
 804                 if (cmd->info.sublen > 3)
 805                         return -EINVAL;
 806                 break;
 807         default:
 808                 return -EINVAL;
 809         }
 810
 811         /* Finish setting up command based on transfer direction
 812          */
 813         if (cmd->read) {
 814                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 815                         return -EINVAL;
 816                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 817                 cmd->scmd.data_len = 9;
 818         } else {
 819                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 820                         return -EINVAL;
 821                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 822         }
 823
 824         DPRINTK("SMU: i2c enqueuing command\n");
 825         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 826                 cmd->read ? "read" : "write", cmd->info.datalen,
 827                 cmd->info.bus, cmd->info.caddr,
 828                 cmd->info.subaddr[0], cmd->info.type);
 829
 830
 831         /* Enqueue command in i2c list, and if empty, enqueue also in
 832          * main command list
 833          */
 834         spin_lock_irqsave(&smu->lock, flags);
 835         if (smu->cmd_i2c_cur == NULL) {
 836                 smu->cmd_i2c_cur = cmd;
 837                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 838                 if (smu->cmd_cur == NULL)
 839                         smu_start_cmd();
 840         } else
 841                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 842         spin_unlock_irqrestore(&smu->lock, flags);
 843
 844         return 0;
 845 }
 846
 847 /*
 848  * Handling of "partitions"
 849  */
 850
 851 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 852 {
 853         DECLARE_COMPLETION(comp);
 854         unsigned int chunk;
 855         struct smu_cmd cmd;
 856         int rc;
 857         u8 params[8];
 858
 859         /* We currently use a chunk size of 0xe. We could check the
 860          * SMU firmware version and use bigger sizes though
 861          */
 862         chunk = 0xe;
 863
 864         while (len) {
 865                 unsigned int clen = min(len, chunk);
 866
 867                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 868                 cmd.data_len = 7;
 869                 cmd.data_buf = params;
 870                 cmd.reply_len = chunk;
 871                 cmd.reply_buf = dest;
 872                 cmd.done = smu_done_complete;
 873                 cmd.misc = &comp;
 874                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 875                 params[1] = 0x4;
 876                 *((u32 *)&params[2]) = addr;
 877                 params[6] = clen;
 878
 879                 rc = smu_queue_cmd(&cmd);
 880                 if (rc)
 881                         return rc;
 882                 wait_for_completion(&comp);
 883                 if (cmd.status != 0)
 884                         return rc;
 885                 if (cmd.reply_len != clen) {
 886                         printk(KERN_DEBUG "SMU: short read in "
 887                                "smu_read_datablock, got: %d, want: %d\n",
 888                                cmd.reply_len, clen);
 889                         return -EIO;
 890                 }
 891                 len -= clen;
 892                 addr += clen;
 893                 dest += clen;
 894         }
 895         return 0;
 896 }
 897
 898 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 899 {
 900         DECLARE_COMPLETION(comp);
 901         struct smu_simple_cmd cmd;
 902         unsigned int addr, len, tlen;
 903         struct smu_sdbp_header *hdr;
 904         struct property *prop;
 905
 906         /* First query the partition info */
 907         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 908         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 909                          smu_done_complete, &comp,
 910                          SMU_CMD_PARTITION_LATEST, id);
 911         wait_for_completion(&comp);
 912         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 913                 cmd.cmd.status, cmd.cmd.reply_len);
 914
 915         /* Partition doesn't exist (or other error) */
 916         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 917                 return NULL;
 918
 919         /* Fetch address and length from reply */
 920         addr = *((u16 *)cmd.buffer);
 921         len = cmd.buffer[3] << 2;
 922         /* Calucluate total length to allocate, including the 17 bytes
 923          * for "sdb-partition-XX" that we append at the end of the buffer
 924          */
 925         tlen = sizeof(struct property) + len + 18;
 926
 927         prop = kcalloc(tlen, 1, GFP_KERNEL);
 928         if (prop == NULL)
 929                 return NULL;
 930         hdr = (struct smu_sdbp_header *)(prop + 1);
 931         prop->name = ((char *)prop) + tlen - 18;
 932         sprintf(prop->name, "sdb-partition-%02x", id);
 933         prop->length = len;
 934         prop->value = (unsigned char *)hdr;
 935         prop->next = NULL;
 936
 937         /* Read the datablock */
 938         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 939                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 940                        "partition %02x !\n", id);
 941                 goto failure;
 942         }
 943
 944         /* Got it, check a few things and create the property */
 945         if (hdr->id != id) {
 946                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 947                        "%02x !\n", id, hdr->id);
 948                 goto failure;
 949         }
 950         if (prom_add_property(smu->of_node, prop)) {
 951                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 952                        "property !\n", id);
 953                 goto failure;
 954         }
 955
 956         return hdr;
 957  failure:
 958         kfree(prop);
 959         return NULL;
 960 }
 961
 962 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
 963  * when interruptible is 1
 964  */
 965 struct smu_sdbp_header *__smu_get_sdb_partition(int id, unsigned int *size,
 966                                                 int interruptible)
 967 {
 968         char pname[32];
 969         struct smu_sdbp_header *part;
 970
 971         if (!smu)
 972                 return NULL;
 973
 974         sprintf(pname, "sdb-partition-%02x", id);
 975
 976         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
 977
 978         if (interruptible) {
 979                 int rc;
 980                 rc = mutex_lock_interruptible(&smu_part_access);
 981                 if (rc)
 982                         return ERR_PTR(rc);
 983         } else
 984                 mutex_lock(&smu_part_access);
 985
 986         part = (struct smu_sdbp_header *)get_property(smu->of_node,
 987                                                       pname, size);
 988         if (part == NULL) {
 989                 DPRINTK("trying to extract from SMU ...\n");
 990                 part = smu_create_sdb_partition(id);
 991                 if (part != NULL && size)
 992                         *size = part->len << 2;
 993         }
 994         mutex_unlock(&smu_part_access);
 995         return part;
 996 }
 997
 998 struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
 999 {
1000         return __smu_get_sdb_partition(id, size, 0);
1001 }
1002 EXPORT_SYMBOL(smu_get_sdb_partition);
1003
1004
1005 /*
1006  * Userland driver interface
1007  */
1008
1009
1010 static LIST_HEAD(smu_clist);
1011 static DEFINE_SPINLOCK(smu_clist_lock);
1012
1013 enum smu_file_mode {
1014         smu_file_commands,
1015         smu_file_events,
1016         smu_file_closing
1017 };
1018
1019 struct smu_private
1020 {
1021         struct list_head        list;
1022         enum smu_file_mode      mode;
1023         int                     busy;
1024         struct smu_cmd          cmd;
1025         spinlock_t              lock;
1026         wait_queue_head_t       wait;
1027         u8                      buffer[SMU_MAX_DATA];
1028 };
1029
1030
1031 static int smu_open(struct inode *inode, struct file *file)
1032 {
1033         struct smu_private *pp;
1034         unsigned long flags;
1035
1036         pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
1037         if (pp == 0)
1038                 return -ENOMEM;
1039         memset(pp, 0, sizeof(struct smu_private));
1040         spin_lock_init(&pp->lock);
1041         pp->mode = smu_file_commands;
1042         init_waitqueue_head(&pp->wait);
1043
1044         spin_lock_irqsave(&smu_clist_lock, flags);
1045         list_add(&pp->list, &smu_clist);
1046         spin_unlock_irqrestore(&smu_clist_lock, flags);
1047         file->private_data = pp;
1048
1049         return 0;
1050 }
1051
1052
1053 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1054 {
1055         struct smu_private *pp = misc;
1056
1057         wake_up_all(&pp->wait);
1058 }
1059
1060
1061 static ssize_t smu_write(struct file *file, const char __user *buf,
1062                          size_t count, loff_t *ppos)
1063 {
1064         struct smu_private *pp = file->private_data;
1065         unsigned long flags;
1066         struct smu_user_cmd_hdr hdr;
1067         int rc = 0;
1068
1069         if (pp->busy)
1070                 return -EBUSY;
1071         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1072                 return -EFAULT;
1073         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1074                 pp->mode = smu_file_events;
1075                 return 0;
1076         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1077                 struct smu_sdbp_header *part;
1078                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1079                 if (part == NULL)
1080                         return -EINVAL;
1081                 else if (IS_ERR(part))
1082                         return PTR_ERR(part);
1083                 return 0;
1084         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1085                 return -EINVAL;
1086         else if (pp->mode != smu_file_commands)
1087                 return -EBADFD;
1088         else if (hdr.data_len > SMU_MAX_DATA)
1089                 return -EINVAL;
1090
1091         spin_lock_irqsave(&pp->lock, flags);
1092         if (pp->busy) {
1093                 spin_unlock_irqrestore(&pp->lock, flags);
1094                 return -EBUSY;
1095         }
1096         pp->busy = 1;
1097         pp->cmd.status = 1;
1098         spin_unlock_irqrestore(&pp->lock, flags);
1099
1100         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1101                 pp->busy = 0;
1102                 return -EFAULT;
1103         }
1104
1105         pp->cmd.cmd = hdr.cmd;
1106         pp->cmd.data_len = hdr.data_len;
1107         pp->cmd.reply_len = SMU_MAX_DATA;
1108         pp->cmd.data_buf = pp->buffer;
1109         pp->cmd.reply_buf = pp->buffer;
1110         pp->cmd.done = smu_user_cmd_done;
1111         pp->cmd.misc = pp;
1112         rc = smu_queue_cmd(&pp->cmd);
1113         if (rc < 0)
1114                 return rc;
1115         return count;
1116 }
1117
1118
1119 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1120                                 char __user *buf, size_t count)
1121 {
1122         DECLARE_WAITQUEUE(wait, current);
1123         struct smu_user_reply_hdr hdr;
1124         unsigned long flags;
1125         int size, rc = 0;
1126
1127         if (!pp->busy)
1128                 return 0;
1129         if (count < sizeof(struct smu_user_reply_hdr))
1130                 return -EOVERFLOW;
1131         spin_lock_irqsave(&pp->lock, flags);
1132         if (pp->cmd.status == 1) {
1133                 if (file->f_flags & O_NONBLOCK)
1134                         return -EAGAIN;
1135                 add_wait_queue(&pp->wait, &wait);
1136                 for (;;) {
1137                         set_current_state(TASK_INTERRUPTIBLE);
1138                         rc = 0;
1139                         if (pp->cmd.status != 1)
1140                                 break;
1141                         rc = -ERESTARTSYS;
1142                         if (signal_pending(current))
1143                                 break;
1144                         spin_unlock_irqrestore(&pp->lock, flags);
1145                         schedule();
1146                         spin_lock_irqsave(&pp->lock, flags);
1147                 }
1148                 set_current_state(TASK_RUNNING);
1149                 remove_wait_queue(&pp->wait, &wait);
1150         }
1151         spin_unlock_irqrestore(&pp->lock, flags);
1152         if (rc)
1153                 return rc;
1154         if (pp->cmd.status != 0)
1155                 pp->cmd.reply_len = 0;
1156         size = sizeof(hdr) + pp->cmd.reply_len;
1157         if (count < size)
1158                 size = count;
1159         rc = size;
1160         hdr.status = pp->cmd.status;
1161         hdr.reply_len = pp->cmd.reply_len;
1162         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1163                 return -EFAULT;
1164         size -= sizeof(hdr);
1165         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1166                 return -EFAULT;
1167         pp->busy = 0;
1168
1169         return rc;
1170 }
1171
1172
1173 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1174                                char __user *buf, size_t count)
1175 {
1176         /* Not implemented */
1177         msleep_interruptible(1000);
1178         return 0;
1179 }
1180
1181
1182 static ssize_t smu_read(struct file *file, char __user *buf,
1183                         size_t count, loff_t *ppos)
1184 {
1185         struct smu_private *pp = file->private_data;
1186
1187         if (pp->mode == smu_file_commands)
1188                 return smu_read_command(file, pp, buf, count);
1189         if (pp->mode == smu_file_events)
1190                 return smu_read_events(file, pp, buf, count);
1191
1192         return -EBADFD;
1193 }
1194
1195 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1196 {
1197         struct smu_private *pp = file->private_data;
1198         unsigned int mask = 0;
1199         unsigned long flags;
1200
1201         if (pp == 0)
1202                 return 0;
1203
1204         if (pp->mode == smu_file_commands) {
1205                 poll_wait(file, &pp->wait, wait);
1206
1207                 spin_lock_irqsave(&pp->lock, flags);
1208                 if (pp->busy && pp->cmd.status != 1)
1209                         mask |= POLLIN;
1210                 spin_unlock_irqrestore(&pp->lock, flags);
1211         } if (pp->mode == smu_file_events) {
1212                 /* Not yet implemented */
1213         }
1214         return mask;
1215 }
1216
1217 static int smu_release(struct inode *inode, struct file *file)
1218 {
1219         struct smu_private *pp = file->private_data;
1220         unsigned long flags;
1221         unsigned int busy;
1222
1223         if (pp == 0)
1224                 return 0;
1225
1226         file->private_data = NULL;
1227
1228         /* Mark file as closing to avoid races with new request */
1229         spin_lock_irqsave(&pp->lock, flags);
1230         pp->mode = smu_file_closing;
1231         busy = pp->busy;
1232
1233         /* Wait for any pending request to complete */
1234         if (busy && pp->cmd.status == 1) {
1235                 DECLARE_WAITQUEUE(wait, current);
1236
1237                 add_wait_queue(&pp->wait, &wait);
1238                 for (;;) {
1239                         set_current_state(TASK_UNINTERRUPTIBLE);
1240                         if (pp->cmd.status != 1)
1241                                 break;
1242                         spin_lock_irqsave(&pp->lock, flags);
1243                         schedule();
1244                         spin_unlock_irqrestore(&pp->lock, flags);
1245                 }
1246                 set_current_state(TASK_RUNNING);
1247                 remove_wait_queue(&pp->wait, &wait);
1248         }
1249         spin_unlock_irqrestore(&pp->lock, flags);
1250
1251         spin_lock_irqsave(&smu_clist_lock, flags);
1252         list_del(&pp->list);
1253         spin_unlock_irqrestore(&smu_clist_lock, flags);
1254         kfree(pp);
1255
1256         return 0;
1257 }
1258
1259
1260 static struct file_operations smu_device_fops = {
1261         .llseek         = no_llseek,
1262         .read           = smu_read,
1263         .write          = smu_write,
1264         .poll           = smu_fpoll,
1265         .open           = smu_open,
1266         .release        = smu_release,
1267 };
1268
1269 static struct miscdevice pmu_device = {
1270         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1271 };
1272
1273 static int smu_device_init(void)
1274 {
1275         if (!smu)
1276                 return -ENODEV;
1277         if (misc_register(&pmu_device) < 0)
1278                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1279         return 0;
1280 }
1281 device_initcall(smu_device_init);