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
  39 #include <asm/byteorder.h>
  40 #include <asm/io.h>
  41 #include <asm/prom.h>
  42 #include <asm/machdep.h>
  43 #include <asm/pmac_feature.h>
  44 #include <asm/smu.h>
  45 #include <asm/sections.h>
  46 #include <asm/abs_addr.h>
  47 #include <asm/uaccess.h>
  48 #include <asm/of_device.h>
  49
  50 #define VERSION "0.7"
  51 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  52
  53 #undef DEBUG_SMU
  54
  55 #ifdef DEBUG_SMU
  56 #define DPRINTK(fmt, args...) do { udbg_printf(KERN_DEBUG fmt , ##args); } while (0)
  57 #else
  58 #define DPRINTK(fmt, args...) do { } while (0)
  59 #endif
  60
  61 /*
  62  * This is the command buffer passed to the SMU hardware
  63  */
  64 #define SMU_MAX_DATA    254
  65
  66 struct smu_cmd_buf {
  67         u8 cmd;
  68         u8 length;
  69         u8 data[SMU_MAX_DATA];
  70 };
  71
  72 struct smu_device {
  73         spinlock_t              lock;
  74         struct device_node      *of_node;
  75         struct of_device        *of_dev;
  76         int                     doorbell;       /* doorbell gpio */
  77         u32 __iomem             *db_buf;        /* doorbell buffer */
  78         int                     db_irq;
  79         int                     msg;
  80         int                     msg_irq;
  81         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  82         u32                     cmd_buf_abs;    /* command buffer absolute */
  83         struct list_head        cmd_list;
  84         struct smu_cmd          *cmd_cur;       /* pending command */
  85         struct list_head        cmd_i2c_list;
  86         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  87         struct timer_list       i2c_timer;
  88 };
  89
  90 /*
  91  * I don't think there will ever be more than one SMU, so
  92  * for now, just hard code that
  93  */
  94 static struct smu_device        *smu;
  95 static DECLARE_MUTEX(smu_part_access);
  96
  97 /*
  98  * SMU driver low level stuff
  99  */
 100
 101 static void smu_start_cmd(void)
 102 {
 103         unsigned long faddr, fend;
 104         struct smu_cmd *cmd;
 105
 106         if (list_empty(&smu->cmd_list))
 107                 return;
 108
 109         /* Fetch first command in queue */
 110         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 111         smu->cmd_cur = cmd;
 112         list_del(&cmd->link);
 113
 114         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 115                 cmd->data_len);
 116         DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 117                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 118                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 119                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 120                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 121
 122         /* Fill the SMU command buffer */
 123         smu->cmd_buf->cmd = cmd->cmd;
 124         smu->cmd_buf->length = cmd->data_len;
 125         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 126
 127         /* Flush command and data to RAM */
 128         faddr = (unsigned long)smu->cmd_buf;
 129         fend = faddr + smu->cmd_buf->length + 2;
 130         flush_inval_dcache_range(faddr, fend);
 131
 132         /* This isn't exactly a DMA mapping here, I suspect
 133          * the SMU is actually communicating with us via i2c to the
 134          * northbridge or the CPU to access RAM.
 135          */
 136         writel(smu->cmd_buf_abs, smu->db_buf);
 137
 138         /* Ring the SMU doorbell */
 139         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 140 }
 141
 142
 143 static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs)
 144 {
 145         unsigned long flags;
 146         struct smu_cmd *cmd;
 147         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 148         void *misc = NULL;
 149         u8 gpio;
 150         int rc = 0;
 151
 152         /* SMU completed the command, well, we hope, let's make sure
 153          * of it
 154          */
 155         spin_lock_irqsave(&smu->lock, flags);
 156
 157         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 158         if ((gpio & 7) != 7) {
 159                 spin_unlock_irqrestore(&smu->lock, flags);
 160                 return IRQ_HANDLED;
 161         }
 162
 163         cmd = smu->cmd_cur;
 164         smu->cmd_cur = NULL;
 165         if (cmd == NULL)
 166                 goto bail;
 167
 168         if (rc == 0) {
 169                 unsigned long faddr;
 170                 int reply_len;
 171                 u8 ack;
 172
 173                 /* CPU might have brought back the cache line, so we need
 174                  * to flush again before peeking at the SMU response. We
 175                  * flush the entire buffer for now as we haven't read the
 176                  * reply lenght (it's only 2 cache lines anyway)
 177                  */
 178                 faddr = (unsigned long)smu->cmd_buf;
 179                 flush_inval_dcache_range(faddr, faddr + 256);
 180
 181                 /* Now check ack */
 182                 ack = (~cmd->cmd) & 0xff;
 183                 if (ack != smu->cmd_buf->cmd) {
 184                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 185                                 ack, smu->cmd_buf->cmd);
 186                         rc = -EIO;
 187                 }
 188                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 189                 DPRINTK("SMU: reply len: %d\n", reply_len);
 190                 if (reply_len > cmd->reply_len) {
 191                         printk(KERN_WARNING "SMU: reply buffer too small,"
 192                                "got %d bytes for a %d bytes buffer\n",
 193                                reply_len, cmd->reply_len);
 194                         reply_len = cmd->reply_len;
 195                 }
 196                 cmd->reply_len = reply_len;
 197                 if (cmd->reply_buf && reply_len)
 198                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 199         }
 200
 201         /* Now complete the command. Write status last in order as we lost
 202          * ownership of the command structure as soon as it's no longer -1
 203          */
 204         done = cmd->done;
 205         misc = cmd->misc;
 206         mb();
 207         cmd->status = rc;
 208  bail:
 209         /* Start next command if any */
 210         smu_start_cmd();
 211         spin_unlock_irqrestore(&smu->lock, flags);
 212
 213         /* Call command completion handler if any */
 214         if (done)
 215                 done(cmd, misc);
 216
 217         /* It's an edge interrupt, nothing to do */
 218         return IRQ_HANDLED;
 219 }
 220
 221
 222 static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
 223 {
 224         /* I don't quite know what to do with this one, we seem to never
 225          * receive it, so I suspect we have to arm it someway in the SMU
 226          * to start getting events that way.
 227          */
 228
 229         printk(KERN_INFO "SMU: message interrupt !\n");
 230
 231         /* It's an edge interrupt, nothing to do */
 232         return IRQ_HANDLED;
 233 }
 234
 235
 236 /*
 237  * Queued command management.
 238  *
 239  */
 240
 241 int smu_queue_cmd(struct smu_cmd *cmd)
 242 {
 243         unsigned long flags;
 244
 245         if (smu == NULL)
 246                 return -ENODEV;
 247         if (cmd->data_len > SMU_MAX_DATA ||
 248             cmd->reply_len > SMU_MAX_DATA)
 249                 return -EINVAL;
 250
 251         cmd->status = 1;
 252         spin_lock_irqsave(&smu->lock, flags);
 253         list_add_tail(&cmd->link, &smu->cmd_list);
 254         if (smu->cmd_cur == NULL)
 255                 smu_start_cmd();
 256         spin_unlock_irqrestore(&smu->lock, flags);
 257
 258         return 0;
 259 }
 260 EXPORT_SYMBOL(smu_queue_cmd);
 261
 262
 263 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 264                      unsigned int data_len,
 265                      void (*done)(struct smu_cmd *cmd, void *misc),
 266                      void *misc, ...)
 267 {
 268         struct smu_cmd *cmd = &scmd->cmd;
 269         va_list list;
 270         int i;
 271
 272         if (data_len > sizeof(scmd->buffer))
 273                 return -EINVAL;
 274
 275         memset(scmd, 0, sizeof(*scmd));
 276         cmd->cmd = command;
 277         cmd->data_len = data_len;
 278         cmd->data_buf = scmd->buffer;
 279         cmd->reply_len = sizeof(scmd->buffer);
 280         cmd->reply_buf = scmd->buffer;
 281         cmd->done = done;
 282         cmd->misc = misc;
 283
 284         va_start(list, misc);
 285         for (i = 0; i < data_len; ++i)
 286                 scmd->buffer[i] = (u8)va_arg(list, int);
 287         va_end(list);
 288
 289         return smu_queue_cmd(cmd);
 290 }
 291 EXPORT_SYMBOL(smu_queue_simple);
 292
 293
 294 void smu_poll(void)
 295 {
 296         u8 gpio;
 297
 298         if (smu == NULL)
 299                 return;
 300
 301         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 302         if ((gpio & 7) == 7)
 303                 smu_db_intr(smu->db_irq, smu, NULL);
 304 }
 305 EXPORT_SYMBOL(smu_poll);
 306
 307
 308 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 309 {
 310         struct completion *comp = misc;
 311
 312         complete(comp);
 313 }
 314 EXPORT_SYMBOL(smu_done_complete);
 315
 316
 317 void smu_spinwait_cmd(struct smu_cmd *cmd)
 318 {
 319         while(cmd->status == 1)
 320                 smu_poll();
 321 }
 322 EXPORT_SYMBOL(smu_spinwait_cmd);
 323
 324
 325 /* RTC low level commands */
 326 static inline int bcd2hex (int n)
 327 {
 328         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 329 }
 330
 331
 332 static inline int hex2bcd (int n)
 333 {
 334         return ((n / 10) << 4) + (n % 10);
 335 }
 336
 337
 338 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 339                                         struct rtc_time *time)
 340 {
 341         cmd_buf->cmd = 0x8e;
 342         cmd_buf->length = 8;
 343         cmd_buf->data[0] = 0x80;
 344         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 345         cmd_buf->data[2] = hex2bcd(time->tm_min);
 346         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 347         cmd_buf->data[4] = time->tm_wday;
 348         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 349         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 350         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 351 }
 352
 353
 354 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 355 {
 356         struct smu_simple_cmd cmd;
 357         int rc;
 358
 359         if (smu == NULL)
 360                 return -ENODEV;
 361
 362         memset(time, 0, sizeof(struct rtc_time));
 363         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 364                               SMU_CMD_RTC_GET_DATETIME);
 365         if (rc)
 366                 return rc;
 367         smu_spinwait_simple(&cmd);
 368
 369         time->tm_sec = bcd2hex(cmd.buffer[0]);
 370         time->tm_min = bcd2hex(cmd.buffer[1]);
 371         time->tm_hour = bcd2hex(cmd.buffer[2]);
 372         time->tm_wday = bcd2hex(cmd.buffer[3]);
 373         time->tm_mday = bcd2hex(cmd.buffer[4]);
 374         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 375         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 376
 377         return 0;
 378 }
 379
 380
 381 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 382 {
 383         struct smu_simple_cmd cmd;
 384         int rc;
 385
 386         if (smu == NULL)
 387                 return -ENODEV;
 388
 389         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 390                               SMU_CMD_RTC_SET_DATETIME,
 391                               hex2bcd(time->tm_sec),
 392                               hex2bcd(time->tm_min),
 393                               hex2bcd(time->tm_hour),
 394                               time->tm_wday,
 395                               hex2bcd(time->tm_mday),
 396                               hex2bcd(time->tm_mon) + 1,
 397                               hex2bcd(time->tm_year - 100));
 398         if (rc)
 399                 return rc;
 400         smu_spinwait_simple(&cmd);
 401
 402         return 0;
 403 }
 404
 405
 406 void smu_shutdown(void)
 407 {
 408         struct smu_simple_cmd cmd;
 409
 410         if (smu == NULL)
 411                 return;
 412
 413         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 414                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 415                 return;
 416         smu_spinwait_simple(&cmd);
 417         for (;;)
 418                 ;
 419 }
 420
 421
 422 void smu_restart(void)
 423 {
 424         struct smu_simple_cmd cmd;
 425
 426         if (smu == NULL)
 427                 return;
 428
 429         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 430                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 431                 return;
 432         smu_spinwait_simple(&cmd);
 433         for (;;)
 434                 ;
 435 }
 436
 437
 438 int smu_present(void)
 439 {
 440         return smu != NULL;
 441 }
 442 EXPORT_SYMBOL(smu_present);
 443
 444
 445 int __init smu_init (void)
 446 {
 447         struct device_node *np;
 448         u32 *data;
 449
 450         np = of_find_node_by_type(NULL, "smu");
 451         if (np == NULL)
 452                 return -ENODEV;
 453
 454         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
 455
 456         if (smu_cmdbuf_abs == 0) {
 457                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 458                 return -EINVAL;
 459         }
 460
 461         smu = alloc_bootmem(sizeof(struct smu_device));
 462         if (smu == NULL)
 463                 return -ENOMEM;
 464         memset(smu, 0, sizeof(*smu));
 465
 466         spin_lock_init(&smu->lock);
 467         INIT_LIST_HEAD(&smu->cmd_list);
 468         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 469         smu->of_node = np;
 470         smu->db_irq = NO_IRQ;
 471         smu->msg_irq = NO_IRQ;
 472         init_timer(&smu->i2c_timer);
 473
 474         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 475          * 32 bits value safely
 476          */
 477         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 478         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 479
 480         np = of_find_node_by_name(NULL, "smu-doorbell");
 481         if (np == NULL) {
 482                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 483                 goto fail;
 484         }
 485         data = (u32 *)get_property(np, "reg", NULL);
 486         if (data == NULL) {
 487                 of_node_put(np);
 488                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 489                 goto fail;
 490         }
 491
 492         /* Current setup has one doorbell GPIO that does both doorbell
 493          * and ack. GPIOs are at 0x50, best would be to find that out
 494          * in the device-tree though.
 495          */
 496         smu->doorbell = *data;
 497         if (smu->doorbell < 0x50)
 498                 smu->doorbell += 0x50;
 499         if (np->n_intrs > 0)
 500                 smu->db_irq = np->intrs[0].line;
 501
 502         of_node_put(np);
 503
 504         /* Now look for the smu-interrupt GPIO */
 505         do {
 506                 np = of_find_node_by_name(NULL, "smu-interrupt");
 507                 if (np == NULL)
 508                         break;
 509                 data = (u32 *)get_property(np, "reg", NULL);
 510                 if (data == NULL) {
 511                         of_node_put(np);
 512                         break;
 513                 }
 514                 smu->msg = *data;
 515                 if (smu->msg < 0x50)
 516                         smu->msg += 0x50;
 517                 if (np->n_intrs > 0)
 518                         smu->msg_irq = np->intrs[0].line;
 519                 of_node_put(np);
 520         } while(0);
 521
 522         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 523          * device-tree entry giving the address. Best would probably to use
 524          * an offset for K2 base though, but let's do it that way for now.
 525          */
 526         smu->db_buf = ioremap(0x8000860c, 0x1000);
 527         if (smu->db_buf == NULL) {
 528                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 529                 goto fail;
 530         }
 531
 532         sys_ctrler = SYS_CTRLER_SMU;
 533         return 0;
 534
 535  fail:
 536         smu = NULL;
 537         return -ENXIO;
 538
 539 }
 540
 541
 542 static int smu_late_init(void)
 543 {
 544         if (!smu)
 545                 return 0;
 546
 547         /*
 548          * Try to request the interrupts
 549          */
 550
 551         if (smu->db_irq != NO_IRQ) {
 552                 if (request_irq(smu->db_irq, smu_db_intr,
 553                                 SA_SHIRQ, "SMU doorbell", smu) < 0) {
 554                         printk(KERN_WARNING "SMU: can't "
 555                                "request interrupt %d\n",
 556                                smu->db_irq);
 557                         smu->db_irq = NO_IRQ;
 558                 }
 559         }
 560
 561         if (smu->msg_irq != NO_IRQ) {
 562                 if (request_irq(smu->msg_irq, smu_msg_intr,
 563                                 SA_SHIRQ, "SMU message", smu) < 0) {
 564                         printk(KERN_WARNING "SMU: can't "
 565                                "request interrupt %d\n",
 566                                smu->msg_irq);
 567                         smu->msg_irq = NO_IRQ;
 568                 }
 569         }
 570
 571         return 0;
 572 }
 573 arch_initcall(smu_late_init);
 574
 575 /*
 576  * sysfs visibility
 577  */
 578
 579 static void smu_expose_childs(void *unused)
 580 {
 581         struct device_node *np;
 582
 583         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;) {
 584                 if (device_is_compatible(np, "smu-i2c")) {
 585                         char name[32];
 586                         u32 *reg = (u32 *)get_property(np, "reg", NULL);
 587
 588                         if (reg == NULL)
 589                                 continue;
 590                         sprintf(name, "smu-i2c-%02x", *reg);
 591                         of_platform_device_create(np, name, &smu->of_dev->dev);
 592                 }
 593         }
 594
 595 }
 596
 597 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
 598
 599 static int smu_platform_probe(struct of_device* dev,
 600                               const struct of_device_id *match)
 601 {
 602         if (!smu)
 603                 return -ENODEV;
 604         smu->of_dev = dev;
 605
 606         /*
 607          * Ok, we are matched, now expose all i2c busses. We have to defer
 608          * that unfortunately or it would deadlock inside the device model
 609          */
 610         schedule_work(&smu_expose_childs_work);
 611
 612         return 0;
 613 }
 614
 615 static struct of_device_id smu_platform_match[] =
 616 {
 617         {
 618                 .type           = "smu",
 619         },
 620         {},
 621 };
 622
 623 static struct of_platform_driver smu_of_platform_driver =
 624 {
 625         .name           = "smu",
 626         .match_table    = smu_platform_match,
 627         .probe          = smu_platform_probe,
 628 };
 629
 630 static int __init smu_init_sysfs(void)
 631 {
 632         int rc;
 633
 634         /*
 635          * Due to sysfs bogosity, a sysdev is not a real device, so
 636          * we should in fact create both if we want sysdev semantics
 637          * for power management.
 638          * For now, we don't power manage machines with an SMU chip,
 639          * I'm a bit too far from figuring out how that works with those
 640          * new chipsets, but that will come back and bite us
 641          */
 642         rc = of_register_driver(&smu_of_platform_driver);
 643         return 0;
 644 }
 645
 646 device_initcall(smu_init_sysfs);
 647
 648 struct of_device *smu_get_ofdev(void)
 649 {
 650         if (!smu)
 651                 return NULL;
 652         return smu->of_dev;
 653 }
 654
 655 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 656
 657 /*
 658  * i2c interface
 659  */
 660
 661 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 662 {
 663         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 664         void *misc = cmd->misc;
 665         unsigned long flags;
 666
 667         /* Check for read case */
 668         if (!fail && cmd->read) {
 669                 if (cmd->pdata[0] < 1)
 670                         fail = 1;
 671                 else
 672                         memcpy(cmd->info.data, &cmd->pdata[1],
 673                                cmd->info.datalen);
 674         }
 675
 676         DPRINTK("SMU: completing, success: %d\n", !fail);
 677
 678         /* Update status and mark no pending i2c command with lock
 679          * held so nobody comes in while we dequeue an eventual
 680          * pending next i2c command
 681          */
 682         spin_lock_irqsave(&smu->lock, flags);
 683         smu->cmd_i2c_cur = NULL;
 684         wmb();
 685         cmd->status = fail ? -EIO : 0;
 686
 687         /* Is there another i2c command waiting ? */
 688         if (!list_empty(&smu->cmd_i2c_list)) {
 689                 struct smu_i2c_cmd *newcmd;
 690
 691                 /* Fetch it, new current, remove from list */
 692                 newcmd = list_entry(smu->cmd_i2c_list.next,
 693                                     struct smu_i2c_cmd, link);
 694                 smu->cmd_i2c_cur = newcmd;
 695                 list_del(&cmd->link);
 696
 697                 /* Queue with low level smu */
 698                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 699                 if (smu->cmd_cur == NULL)
 700                         smu_start_cmd();
 701         }
 702         spin_unlock_irqrestore(&smu->lock, flags);
 703
 704         /* Call command completion handler if any */
 705         if (done)
 706                 done(cmd, misc);
 707
 708 }
 709
 710
 711 static void smu_i2c_retry(unsigned long data)
 712 {
 713         struct smu_i2c_cmd      *cmd = (struct smu_i2c_cmd *)data;
 714
 715         DPRINTK("SMU: i2c failure, requeuing...\n");
 716
 717         /* requeue command simply by resetting reply_len */
 718         cmd->pdata[0] = 0xff;
 719         cmd->scmd.reply_len = 0x10;
 720         smu_queue_cmd(&cmd->scmd);
 721 }
 722
 723
 724 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 725 {
 726         struct smu_i2c_cmd      *cmd = misc;
 727         int                     fail = 0;
 728
 729         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 730                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 731
 732         /* Check for possible status */
 733         if (scmd->status < 0)
 734                 fail = 1;
 735         else if (cmd->read) {
 736                 if (cmd->stage == 0)
 737                         fail = cmd->pdata[0] != 0;
 738                 else
 739                         fail = cmd->pdata[0] >= 0x80;
 740         } else {
 741                 fail = cmd->pdata[0] != 0;
 742         }
 743
 744         /* Handle failures by requeuing command, after 5ms interval
 745          */
 746         if (fail && --cmd->retries > 0) {
 747                 DPRINTK("SMU: i2c failure, starting timer...\n");
 748                 smu->i2c_timer.function = smu_i2c_retry;
 749                 smu->i2c_timer.data = (unsigned long)cmd;
 750                 smu->i2c_timer.expires = jiffies + msecs_to_jiffies(5);
 751                 add_timer(&smu->i2c_timer);
 752                 return;
 753         }
 754
 755         /* If failure or stage 1, command is complete */
 756         if (fail || cmd->stage != 0) {
 757                 smu_i2c_complete_command(cmd, fail);
 758                 return;
 759         }
 760
 761         DPRINTK("SMU: going to stage 1\n");
 762
 763         /* Ok, initial command complete, now poll status */
 764         scmd->reply_buf = cmd->pdata;
 765         scmd->reply_len = 0x10;
 766         scmd->data_buf = cmd->pdata;
 767         scmd->data_len = 1;
 768         cmd->pdata[0] = 0;
 769         cmd->stage = 1;
 770         cmd->retries = 20;
 771         smu_queue_cmd(scmd);
 772 }
 773
 774
 775 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 776 {
 777         unsigned long flags;
 778
 779         if (smu == NULL)
 780                 return -ENODEV;
 781
 782         /* Fill most fields of scmd */
 783         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 784         cmd->scmd.done = smu_i2c_low_completion;
 785         cmd->scmd.misc = cmd;
 786         cmd->scmd.reply_buf = cmd->pdata;
 787         cmd->scmd.reply_len = 0x10;
 788         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 789         cmd->scmd.status = 1;
 790         cmd->stage = 0;
 791         cmd->pdata[0] = 0xff;
 792         cmd->retries = 20;
 793         cmd->status = 1;
 794
 795         /* Check transfer type, sanitize some "info" fields
 796          * based on transfer type and do more checking
 797          */
 798         cmd->info.caddr = cmd->info.devaddr;
 799         cmd->read = cmd->info.devaddr & 0x01;
 800         switch(cmd->info.type) {
 801         case SMU_I2C_TRANSFER_SIMPLE:
 802                 memset(&cmd->info.sublen, 0, 4);
 803                 break;
 804         case SMU_I2C_TRANSFER_COMBINED:
 805                 cmd->info.devaddr &= 0xfe;
 806         case SMU_I2C_TRANSFER_STDSUB:
 807                 if (cmd->info.sublen > 3)
 808                         return -EINVAL;
 809                 break;
 810         default:
 811                 return -EINVAL;
 812         }
 813
 814         /* Finish setting up command based on transfer direction
 815          */
 816         if (cmd->read) {
 817                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 818                         return -EINVAL;
 819                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 820                 cmd->scmd.data_len = 9;
 821         } else {
 822                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 823                         return -EINVAL;
 824                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 825         }
 826
 827         DPRINTK("SMU: i2c enqueuing command\n");
 828         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 829                 cmd->read ? "read" : "write", cmd->info.datalen,
 830                 cmd->info.bus, cmd->info.caddr,
 831                 cmd->info.subaddr[0], cmd->info.type);
 832
 833
 834         /* Enqueue command in i2c list, and if empty, enqueue also in
 835          * main command list
 836          */
 837         spin_lock_irqsave(&smu->lock, flags);
 838         if (smu->cmd_i2c_cur == NULL) {
 839                 smu->cmd_i2c_cur = cmd;
 840                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 841                 if (smu->cmd_cur == NULL)
 842                         smu_start_cmd();
 843         } else
 844                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 845         spin_unlock_irqrestore(&smu->lock, flags);
 846
 847         return 0;
 848 }
 849
 850 /*
 851  * Handling of "partitions"
 852  */
 853
 854 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 855 {
 856         DECLARE_COMPLETION(comp);
 857         unsigned int chunk;
 858         struct smu_cmd cmd;
 859         int rc;
 860         u8 params[8];
 861
 862         /* We currently use a chunk size of 0xe. We could check the
 863          * SMU firmware version and use bigger sizes though
 864          */
 865         chunk = 0xe;
 866
 867         while (len) {
 868                 unsigned int clen = min(len, chunk);
 869
 870                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 871                 cmd.data_len = 7;
 872                 cmd.data_buf = params;
 873                 cmd.reply_len = chunk;
 874                 cmd.reply_buf = dest;
 875                 cmd.done = smu_done_complete;
 876                 cmd.misc = &comp;
 877                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 878                 params[1] = 0x4;
 879                 *((u32 *)&params[2]) = addr;
 880                 params[6] = clen;
 881
 882                 rc = smu_queue_cmd(&cmd);
 883                 if (rc)
 884                         return rc;
 885                 wait_for_completion(&comp);
 886                 if (cmd.status != 0)
 887                         return rc;
 888                 if (cmd.reply_len != clen) {
 889                         printk(KERN_DEBUG "SMU: short read in "
 890                                "smu_read_datablock, got: %d, want: %d\n",
 891                                cmd.reply_len, clen);
 892                         return -EIO;
 893                 }
 894                 len -= clen;
 895                 addr += clen;
 896                 dest += clen;
 897         }
 898         return 0;
 899 }
 900
 901 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 902 {
 903         DECLARE_COMPLETION(comp);
 904         struct smu_simple_cmd cmd;
 905         unsigned int addr, len, tlen;
 906         struct smu_sdbp_header *hdr;
 907         struct property *prop;
 908
 909         /* First query the partition info */
 910         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 911                          smu_done_complete, &comp,
 912                          SMU_CMD_PARTITION_LATEST, id);
 913         wait_for_completion(&comp);
 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         if (interruptible) {
 977                 int rc;
 978                 rc = down_interruptible(&smu_part_access);
 979                 if (rc)
 980                         return ERR_PTR(rc);
 981         } else
 982                 down(&smu_part_access);
 983
 984         part = (struct smu_sdbp_header *)get_property(smu->of_node,
 985                                                       pname, size);
 986         if (part == NULL) {
 987                 part = smu_create_sdb_partition(id);
 988                 if (part != NULL && size)
 989                         *size = part->len << 2;
 990         }
 991         up(&smu_part_access);
 992         return part;
 993 }
 994
 995 struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
 996 {
 997         return __smu_get_sdb_partition(id, size, 0);
 998 }
 999 EXPORT_SYMBOL(smu_get_sdb_partition);
1000
1001
1002 /*
1003  * Userland driver interface
1004  */
1005
1006
1007 static LIST_HEAD(smu_clist);
1008 static DEFINE_SPINLOCK(smu_clist_lock);
1009
1010 enum smu_file_mode {
1011         smu_file_commands,
1012         smu_file_events,
1013         smu_file_closing
1014 };
1015
1016 struct smu_private
1017 {
1018         struct list_head        list;
1019         enum smu_file_mode      mode;
1020         int                     busy;
1021         struct smu_cmd          cmd;
1022         spinlock_t              lock;
1023         wait_queue_head_t       wait;
1024         u8                      buffer[SMU_MAX_DATA];
1025 };
1026
1027
1028 static int smu_open(struct inode *inode, struct file *file)
1029 {
1030         struct smu_private *pp;
1031         unsigned long flags;
1032
1033         pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
1034         if (pp == 0)
1035                 return -ENOMEM;
1036         memset(pp, 0, sizeof(struct smu_private));
1037         spin_lock_init(&pp->lock);
1038         pp->mode = smu_file_commands;
1039         init_waitqueue_head(&pp->wait);
1040
1041         spin_lock_irqsave(&smu_clist_lock, flags);
1042         list_add(&pp->list, &smu_clist);
1043         spin_unlock_irqrestore(&smu_clist_lock, flags);
1044         file->private_data = pp;
1045
1046         return 0;
1047 }
1048
1049
1050 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1051 {
1052         struct smu_private *pp = misc;
1053
1054         wake_up_all(&pp->wait);
1055 }
1056
1057
1058 static ssize_t smu_write(struct file *file, const char __user *buf,
1059                          size_t count, loff_t *ppos)
1060 {
1061         struct smu_private *pp = file->private_data;
1062         unsigned long flags;
1063         struct smu_user_cmd_hdr hdr;
1064         int rc = 0;
1065
1066         if (pp->busy)
1067                 return -EBUSY;
1068         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1069                 return -EFAULT;
1070         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1071                 pp->mode = smu_file_events;
1072                 return 0;
1073         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1074                 struct smu_sdbp_header *part;
1075                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1076                 if (part == NULL)
1077                         return -EINVAL;
1078                 else if (IS_ERR(part))
1079                         return PTR_ERR(part);
1080                 return 0;
1081         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1082                 return -EINVAL;
1083         else if (pp->mode != smu_file_commands)
1084                 return -EBADFD;
1085         else if (hdr.data_len > SMU_MAX_DATA)
1086                 return -EINVAL;
1087
1088         spin_lock_irqsave(&pp->lock, flags);
1089         if (pp->busy) {
1090                 spin_unlock_irqrestore(&pp->lock, flags);
1091                 return -EBUSY;
1092         }
1093         pp->busy = 1;
1094         pp->cmd.status = 1;
1095         spin_unlock_irqrestore(&pp->lock, flags);
1096
1097         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1098                 pp->busy = 0;
1099                 return -EFAULT;
1100         }
1101
1102         pp->cmd.cmd = hdr.cmd;
1103         pp->cmd.data_len = hdr.data_len;
1104         pp->cmd.reply_len = SMU_MAX_DATA;
1105         pp->cmd.data_buf = pp->buffer;
1106         pp->cmd.reply_buf = pp->buffer;
1107         pp->cmd.done = smu_user_cmd_done;
1108         pp->cmd.misc = pp;
1109         rc = smu_queue_cmd(&pp->cmd);
1110         if (rc < 0)
1111                 return rc;
1112         return count;
1113 }
1114
1115
1116 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1117                                 char __user *buf, size_t count)
1118 {
1119         DECLARE_WAITQUEUE(wait, current);
1120         struct smu_user_reply_hdr hdr;
1121         unsigned long flags;
1122         int size, rc = 0;
1123
1124         if (!pp->busy)
1125                 return 0;
1126         if (count < sizeof(struct smu_user_reply_hdr))
1127                 return -EOVERFLOW;
1128         spin_lock_irqsave(&pp->lock, flags);
1129         if (pp->cmd.status == 1) {
1130                 if (file->f_flags & O_NONBLOCK)
1131                         return -EAGAIN;
1132                 add_wait_queue(&pp->wait, &wait);
1133                 for (;;) {
1134                         set_current_state(TASK_INTERRUPTIBLE);
1135                         rc = 0;
1136                         if (pp->cmd.status != 1)
1137                                 break;
1138                         rc = -ERESTARTSYS;
1139                         if (signal_pending(current))
1140                                 break;
1141                         spin_unlock_irqrestore(&pp->lock, flags);
1142                         schedule();
1143                         spin_lock_irqsave(&pp->lock, flags);
1144                 }
1145                 set_current_state(TASK_RUNNING);
1146                 remove_wait_queue(&pp->wait, &wait);
1147         }
1148         spin_unlock_irqrestore(&pp->lock, flags);
1149         if (rc)
1150                 return rc;
1151         if (pp->cmd.status != 0)
1152                 pp->cmd.reply_len = 0;
1153         size = sizeof(hdr) + pp->cmd.reply_len;
1154         if (count < size)
1155                 size = count;
1156         rc = size;
1157         hdr.status = pp->cmd.status;
1158         hdr.reply_len = pp->cmd.reply_len;
1159         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1160                 return -EFAULT;
1161         size -= sizeof(hdr);
1162         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1163                 return -EFAULT;
1164         pp->busy = 0;
1165
1166         return rc;
1167 }
1168
1169
1170 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1171                                char __user *buf, size_t count)
1172 {
1173         /* Not implemented */
1174         msleep_interruptible(1000);
1175         return 0;
1176 }
1177
1178
1179 static ssize_t smu_read(struct file *file, char __user *buf,
1180                         size_t count, loff_t *ppos)
1181 {
1182         struct smu_private *pp = file->private_data;
1183
1184         if (pp->mode == smu_file_commands)
1185                 return smu_read_command(file, pp, buf, count);
1186         if (pp->mode == smu_file_events)
1187                 return smu_read_events(file, pp, buf, count);
1188
1189         return -EBADFD;
1190 }
1191
1192 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1193 {
1194         struct smu_private *pp = file->private_data;
1195         unsigned int mask = 0;
1196         unsigned long flags;
1197
1198         if (pp == 0)
1199                 return 0;
1200
1201         if (pp->mode == smu_file_commands) {
1202                 poll_wait(file, &pp->wait, wait);
1203
1204                 spin_lock_irqsave(&pp->lock, flags);
1205                 if (pp->busy && pp->cmd.status != 1)
1206                         mask |= POLLIN;
1207                 spin_unlock_irqrestore(&pp->lock, flags);
1208         } if (pp->mode == smu_file_events) {
1209                 /* Not yet implemented */
1210         }
1211         return mask;
1212 }
1213
1214 static int smu_release(struct inode *inode, struct file *file)
1215 {
1216         struct smu_private *pp = file->private_data;
1217         unsigned long flags;
1218         unsigned int busy;
1219
1220         if (pp == 0)
1221                 return 0;
1222
1223         file->private_data = NULL;
1224
1225         /* Mark file as closing to avoid races with new request */
1226         spin_lock_irqsave(&pp->lock, flags);
1227         pp->mode = smu_file_closing;
1228         busy = pp->busy;
1229
1230         /* Wait for any pending request to complete */
1231         if (busy && pp->cmd.status == 1) {
1232                 DECLARE_WAITQUEUE(wait, current);
1233
1234                 add_wait_queue(&pp->wait, &wait);
1235                 for (;;) {
1236                         set_current_state(TASK_UNINTERRUPTIBLE);
1237                         if (pp->cmd.status != 1)
1238                                 break;
1239                         spin_lock_irqsave(&pp->lock, flags);
1240                         schedule();
1241                         spin_unlock_irqrestore(&pp->lock, flags);
1242                 }
1243                 set_current_state(TASK_RUNNING);
1244                 remove_wait_queue(&pp->wait, &wait);
1245         }
1246         spin_unlock_irqrestore(&pp->lock, flags);
1247
1248         spin_lock_irqsave(&smu_clist_lock, flags);
1249         list_del(&pp->list);
1250         spin_unlock_irqrestore(&smu_clist_lock, flags);
1251         kfree(pp);
1252
1253         return 0;
1254 }
1255
1256
1257 static struct file_operations smu_device_fops = {
1258         .llseek         = no_llseek,
1259         .read           = smu_read,
1260         .write          = smu_write,
1261         .poll           = smu_fpoll,
1262         .open           = smu_open,
1263         .release        = smu_release,
1264 };
1265
1266 static struct miscdevice pmu_device = {
1267         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1268 };
1269
1270 static int smu_device_init(void)
1271 {
1272         if (!smu)
1273                 return -ENODEV;
1274         if (misc_register(&pmu_device) < 0)
1275                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1276         return 0;
1277 }
1278 device_initcall(smu_device_init);