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                 if (device_is_compatible(np, "smu-sensors"))
 594                         of_platform_device_create(np, "smu-sensors", &smu->of_dev->dev);
 595         }
 596
 597 }
 598
 599 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
 600
 601 static int smu_platform_probe(struct of_device* dev,
 602                               const struct of_device_id *match)
 603 {
 604         if (!smu)
 605                 return -ENODEV;
 606         smu->of_dev = dev;
 607
 608         /*
 609          * Ok, we are matched, now expose all i2c busses. We have to defer
 610          * that unfortunately or it would deadlock inside the device model
 611          */
 612         schedule_work(&smu_expose_childs_work);
 613
 614         return 0;
 615 }
 616
 617 static struct of_device_id smu_platform_match[] =
 618 {
 619         {
 620                 .type           = "smu",
 621         },
 622         {},
 623 };
 624
 625 static struct of_platform_driver smu_of_platform_driver =
 626 {
 627         .name           = "smu",
 628         .match_table    = smu_platform_match,
 629         .probe          = smu_platform_probe,
 630 };
 631
 632 static int __init smu_init_sysfs(void)
 633 {
 634         int rc;
 635
 636         /*
 637          * Due to sysfs bogosity, a sysdev is not a real device, so
 638          * we should in fact create both if we want sysdev semantics
 639          * for power management.
 640          * For now, we don't power manage machines with an SMU chip,
 641          * I'm a bit too far from figuring out how that works with those
 642          * new chipsets, but that will come back and bite us
 643          */
 644         rc = of_register_driver(&smu_of_platform_driver);
 645         return 0;
 646 }
 647
 648 device_initcall(smu_init_sysfs);
 649
 650 struct of_device *smu_get_ofdev(void)
 651 {
 652         if (!smu)
 653                 return NULL;
 654         return smu->of_dev;
 655 }
 656
 657 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 658
 659 /*
 660  * i2c interface
 661  */
 662
 663 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 664 {
 665         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 666         void *misc = cmd->misc;
 667         unsigned long flags;
 668
 669         /* Check for read case */
 670         if (!fail && cmd->read) {
 671                 if (cmd->pdata[0] < 1)
 672                         fail = 1;
 673                 else
 674                         memcpy(cmd->info.data, &cmd->pdata[1],
 675                                cmd->info.datalen);
 676         }
 677
 678         DPRINTK("SMU: completing, success: %d\n", !fail);
 679
 680         /* Update status and mark no pending i2c command with lock
 681          * held so nobody comes in while we dequeue an eventual
 682          * pending next i2c command
 683          */
 684         spin_lock_irqsave(&smu->lock, flags);
 685         smu->cmd_i2c_cur = NULL;
 686         wmb();
 687         cmd->status = fail ? -EIO : 0;
 688
 689         /* Is there another i2c command waiting ? */
 690         if (!list_empty(&smu->cmd_i2c_list)) {
 691                 struct smu_i2c_cmd *newcmd;
 692
 693                 /* Fetch it, new current, remove from list */
 694                 newcmd = list_entry(smu->cmd_i2c_list.next,
 695                                     struct smu_i2c_cmd, link);
 696                 smu->cmd_i2c_cur = newcmd;
 697                 list_del(&cmd->link);
 698
 699                 /* Queue with low level smu */
 700                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 701                 if (smu->cmd_cur == NULL)
 702                         smu_start_cmd();
 703         }
 704         spin_unlock_irqrestore(&smu->lock, flags);
 705
 706         /* Call command completion handler if any */
 707         if (done)
 708                 done(cmd, misc);
 709
 710 }
 711
 712
 713 static void smu_i2c_retry(unsigned long data)
 714 {
 715         struct smu_i2c_cmd      *cmd = (struct smu_i2c_cmd *)data;
 716
 717         DPRINTK("SMU: i2c failure, requeuing...\n");
 718
 719         /* requeue command simply by resetting reply_len */
 720         cmd->pdata[0] = 0xff;
 721         cmd->scmd.reply_len = 0x10;
 722         smu_queue_cmd(&cmd->scmd);
 723 }
 724
 725
 726 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 727 {
 728         struct smu_i2c_cmd      *cmd = misc;
 729         int                     fail = 0;
 730
 731         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 732                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 733
 734         /* Check for possible status */
 735         if (scmd->status < 0)
 736                 fail = 1;
 737         else if (cmd->read) {
 738                 if (cmd->stage == 0)
 739                         fail = cmd->pdata[0] != 0;
 740                 else
 741                         fail = cmd->pdata[0] >= 0x80;
 742         } else {
 743                 fail = cmd->pdata[0] != 0;
 744         }
 745
 746         /* Handle failures by requeuing command, after 5ms interval
 747          */
 748         if (fail && --cmd->retries > 0) {
 749                 DPRINTK("SMU: i2c failure, starting timer...\n");
 750                 smu->i2c_timer.function = smu_i2c_retry;
 751                 smu->i2c_timer.data = (unsigned long)cmd;
 752                 smu->i2c_timer.expires = jiffies + msecs_to_jiffies(5);
 753                 add_timer(&smu->i2c_timer);
 754                 return;
 755         }
 756
 757         /* If failure or stage 1, command is complete */
 758         if (fail || cmd->stage != 0) {
 759                 smu_i2c_complete_command(cmd, fail);
 760                 return;
 761         }
 762
 763         DPRINTK("SMU: going to stage 1\n");
 764
 765         /* Ok, initial command complete, now poll status */
 766         scmd->reply_buf = cmd->pdata;
 767         scmd->reply_len = 0x10;
 768         scmd->data_buf = cmd->pdata;
 769         scmd->data_len = 1;
 770         cmd->pdata[0] = 0;
 771         cmd->stage = 1;
 772         cmd->retries = 20;
 773         smu_queue_cmd(scmd);
 774 }
 775
 776
 777 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 778 {
 779         unsigned long flags;
 780
 781         if (smu == NULL)
 782                 return -ENODEV;
 783
 784         /* Fill most fields of scmd */
 785         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 786         cmd->scmd.done = smu_i2c_low_completion;
 787         cmd->scmd.misc = cmd;
 788         cmd->scmd.reply_buf = cmd->pdata;
 789         cmd->scmd.reply_len = 0x10;
 790         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 791         cmd->scmd.status = 1;
 792         cmd->stage = 0;
 793         cmd->pdata[0] = 0xff;
 794         cmd->retries = 20;
 795         cmd->status = 1;
 796
 797         /* Check transfer type, sanitize some "info" fields
 798          * based on transfer type and do more checking
 799          */
 800         cmd->info.caddr = cmd->info.devaddr;
 801         cmd->read = cmd->info.devaddr & 0x01;
 802         switch(cmd->info.type) {
 803         case SMU_I2C_TRANSFER_SIMPLE:
 804                 memset(&cmd->info.sublen, 0, 4);
 805                 break;
 806         case SMU_I2C_TRANSFER_COMBINED:
 807                 cmd->info.devaddr &= 0xfe;
 808         case SMU_I2C_TRANSFER_STDSUB:
 809                 if (cmd->info.sublen > 3)
 810                         return -EINVAL;
 811                 break;
 812         default:
 813                 return -EINVAL;
 814         }
 815
 816         /* Finish setting up command based on transfer direction
 817          */
 818         if (cmd->read) {
 819                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 820                         return -EINVAL;
 821                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 822                 cmd->scmd.data_len = 9;
 823         } else {
 824                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 825                         return -EINVAL;
 826                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 827         }
 828
 829         DPRINTK("SMU: i2c enqueuing command\n");
 830         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 831                 cmd->read ? "read" : "write", cmd->info.datalen,
 832                 cmd->info.bus, cmd->info.caddr,
 833                 cmd->info.subaddr[0], cmd->info.type);
 834
 835
 836         /* Enqueue command in i2c list, and if empty, enqueue also in
 837          * main command list
 838          */
 839         spin_lock_irqsave(&smu->lock, flags);
 840         if (smu->cmd_i2c_cur == NULL) {
 841                 smu->cmd_i2c_cur = cmd;
 842                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 843                 if (smu->cmd_cur == NULL)
 844                         smu_start_cmd();
 845         } else
 846                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 847         spin_unlock_irqrestore(&smu->lock, flags);
 848
 849         return 0;
 850 }
 851
 852 /*
 853  * Handling of "partitions"
 854  */
 855
 856 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 857 {
 858         DECLARE_COMPLETION(comp);
 859         unsigned int chunk;
 860         struct smu_cmd cmd;
 861         int rc;
 862         u8 params[8];
 863
 864         /* We currently use a chunk size of 0xe. We could check the
 865          * SMU firmware version and use bigger sizes though
 866          */
 867         chunk = 0xe;
 868
 869         while (len) {
 870                 unsigned int clen = min(len, chunk);
 871
 872                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 873                 cmd.data_len = 7;
 874                 cmd.data_buf = params;
 875                 cmd.reply_len = chunk;
 876                 cmd.reply_buf = dest;
 877                 cmd.done = smu_done_complete;
 878                 cmd.misc = &comp;
 879                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 880                 params[1] = 0x4;
 881                 *((u32 *)&params[2]) = addr;
 882                 params[6] = clen;
 883
 884                 rc = smu_queue_cmd(&cmd);
 885                 if (rc)
 886                         return rc;
 887                 wait_for_completion(&comp);
 888                 if (cmd.status != 0)
 889                         return rc;
 890                 if (cmd.reply_len != clen) {
 891                         printk(KERN_DEBUG "SMU: short read in "
 892                                "smu_read_datablock, got: %d, want: %d\n",
 893                                cmd.reply_len, clen);
 894                         return -EIO;
 895                 }
 896                 len -= clen;
 897                 addr += clen;
 898                 dest += clen;
 899         }
 900         return 0;
 901 }
 902
 903 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 904 {
 905         DECLARE_COMPLETION(comp);
 906         struct smu_simple_cmd cmd;
 907         unsigned int addr, len, tlen;
 908         struct smu_sdbp_header *hdr;
 909         struct property *prop;
 910
 911         /* First query the partition info */
 912         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 913                          smu_done_complete, &comp,
 914                          SMU_CMD_PARTITION_LATEST, id);
 915         wait_for_completion(&comp);
 916
 917         /* Partition doesn't exist (or other error) */
 918         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 919                 return NULL;
 920
 921         /* Fetch address and length from reply */
 922         addr = *((u16 *)cmd.buffer);
 923         len = cmd.buffer[3] << 2;
 924         /* Calucluate total length to allocate, including the 17 bytes
 925          * for "sdb-partition-XX" that we append at the end of the buffer
 926          */
 927         tlen = sizeof(struct property) + len + 18;
 928
 929         prop = kcalloc(tlen, 1, GFP_KERNEL);
 930         if (prop == NULL)
 931                 return NULL;
 932         hdr = (struct smu_sdbp_header *)(prop + 1);
 933         prop->name = ((char *)prop) + tlen - 18;
 934         sprintf(prop->name, "sdb-partition-%02x", id);
 935         prop->length = len;
 936         prop->value = (unsigned char *)hdr;
 937         prop->next = NULL;
 938
 939         /* Read the datablock */
 940         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 941                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 942                        "partition %02x !\n", id);
 943                 goto failure;
 944         }
 945
 946         /* Got it, check a few things and create the property */
 947         if (hdr->id != id) {
 948                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 949                        "%02x !\n", id, hdr->id);
 950                 goto failure;
 951         }
 952         if (prom_add_property(smu->of_node, prop)) {
 953                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 954                        "property !\n", id);
 955                 goto failure;
 956         }
 957
 958         return hdr;
 959  failure:
 960         kfree(prop);
 961         return NULL;
 962 }
 963
 964 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
 965  * when interruptible is 1
 966  */
 967 struct smu_sdbp_header *__smu_get_sdb_partition(int id, unsigned int *size,
 968                                                 int interruptible)
 969 {
 970         char pname[32];
 971         struct smu_sdbp_header *part;
 972
 973         if (!smu)
 974                 return NULL;
 975
 976         sprintf(pname, "sdb-partition-%02x", id);
 977
 978         if (interruptible) {
 979                 int rc;
 980                 rc = down_interruptible(&smu_part_access);
 981                 if (rc)
 982                         return ERR_PTR(rc);
 983         } else
 984                 down(&smu_part_access);
 985
 986         part = (struct smu_sdbp_header *)get_property(smu->of_node,
 987                                                       pname, size);
 988         if (part == NULL) {
 989                 part = smu_create_sdb_partition(id);
 990                 if (part != NULL && size)
 991                         *size = part->len << 2;
 992         }
 993         up(&smu_part_access);
 994         return part;
 995 }
 996
 997 struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
 998 {
 999         return __smu_get_sdb_partition(id, size, 0);
1000 }
1001 EXPORT_SYMBOL(smu_get_sdb_partition);
1002
1003
1004 /*
1005  * Userland driver interface
1006  */
1007
1008
1009 static LIST_HEAD(smu_clist);
1010 static DEFINE_SPINLOCK(smu_clist_lock);
1011
1012 enum smu_file_mode {
1013         smu_file_commands,
1014         smu_file_events,
1015         smu_file_closing
1016 };
1017
1018 struct smu_private
1019 {
1020         struct list_head        list;
1021         enum smu_file_mode      mode;
1022         int                     busy;
1023         struct smu_cmd          cmd;
1024         spinlock_t              lock;
1025         wait_queue_head_t       wait;
1026         u8                      buffer[SMU_MAX_DATA];
1027 };
1028
1029
1030 static int smu_open(struct inode *inode, struct file *file)
1031 {
1032         struct smu_private *pp;
1033         unsigned long flags;
1034
1035         pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
1036         if (pp == 0)
1037                 return -ENOMEM;
1038         memset(pp, 0, sizeof(struct smu_private));
1039         spin_lock_init(&pp->lock);
1040         pp->mode = smu_file_commands;
1041         init_waitqueue_head(&pp->wait);
1042
1043         spin_lock_irqsave(&smu_clist_lock, flags);
1044         list_add(&pp->list, &smu_clist);
1045         spin_unlock_irqrestore(&smu_clist_lock, flags);
1046         file->private_data = pp;
1047
1048         return 0;
1049 }
1050
1051
1052 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1053 {
1054         struct smu_private *pp = misc;
1055
1056         wake_up_all(&pp->wait);
1057 }
1058
1059
1060 static ssize_t smu_write(struct file *file, const char __user *buf,
1061                          size_t count, loff_t *ppos)
1062 {
1063         struct smu_private *pp = file->private_data;
1064         unsigned long flags;
1065         struct smu_user_cmd_hdr hdr;
1066         int rc = 0;
1067
1068         if (pp->busy)
1069                 return -EBUSY;
1070         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1071                 return -EFAULT;
1072         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1073                 pp->mode = smu_file_events;
1074                 return 0;
1075         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1076                 struct smu_sdbp_header *part;
1077                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1078                 if (part == NULL)
1079                         return -EINVAL;
1080                 else if (IS_ERR(part))
1081                         return PTR_ERR(part);
1082                 return 0;
1083         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1084                 return -EINVAL;
1085         else if (pp->mode != smu_file_commands)
1086                 return -EBADFD;
1087         else if (hdr.data_len > SMU_MAX_DATA)
1088                 return -EINVAL;
1089
1090         spin_lock_irqsave(&pp->lock, flags);
1091         if (pp->busy) {
1092                 spin_unlock_irqrestore(&pp->lock, flags);
1093                 return -EBUSY;
1094         }
1095         pp->busy = 1;
1096         pp->cmd.status = 1;
1097         spin_unlock_irqrestore(&pp->lock, flags);
1098
1099         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1100                 pp->busy = 0;
1101                 return -EFAULT;
1102         }
1103
1104         pp->cmd.cmd = hdr.cmd;
1105         pp->cmd.data_len = hdr.data_len;
1106         pp->cmd.reply_len = SMU_MAX_DATA;
1107         pp->cmd.data_buf = pp->buffer;
1108         pp->cmd.reply_buf = pp->buffer;
1109         pp->cmd.done = smu_user_cmd_done;
1110         pp->cmd.misc = pp;
1111         rc = smu_queue_cmd(&pp->cmd);
1112         if (rc < 0)
1113                 return rc;
1114         return count;
1115 }
1116
1117
1118 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1119                                 char __user *buf, size_t count)
1120 {
1121         DECLARE_WAITQUEUE(wait, current);
1122         struct smu_user_reply_hdr hdr;
1123         unsigned long flags;
1124         int size, rc = 0;
1125
1126         if (!pp->busy)
1127                 return 0;
1128         if (count < sizeof(struct smu_user_reply_hdr))
1129                 return -EOVERFLOW;
1130         spin_lock_irqsave(&pp->lock, flags);
1131         if (pp->cmd.status == 1) {
1132                 if (file->f_flags & O_NONBLOCK)
1133                         return -EAGAIN;
1134                 add_wait_queue(&pp->wait, &wait);
1135                 for (;;) {
1136                         set_current_state(TASK_INTERRUPTIBLE);
1137                         rc = 0;
1138                         if (pp->cmd.status != 1)
1139                                 break;
1140                         rc = -ERESTARTSYS;
1141                         if (signal_pending(current))
1142                                 break;
1143                         spin_unlock_irqrestore(&pp->lock, flags);
1144                         schedule();
1145                         spin_lock_irqsave(&pp->lock, flags);
1146                 }
1147                 set_current_state(TASK_RUNNING);
1148                 remove_wait_queue(&pp->wait, &wait);
1149         }
1150         spin_unlock_irqrestore(&pp->lock, flags);
1151         if (rc)
1152                 return rc;
1153         if (pp->cmd.status != 0)
1154                 pp->cmd.reply_len = 0;
1155         size = sizeof(hdr) + pp->cmd.reply_len;
1156         if (count < size)
1157                 size = count;
1158         rc = size;
1159         hdr.status = pp->cmd.status;
1160         hdr.reply_len = pp->cmd.reply_len;
1161         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1162                 return -EFAULT;
1163         size -= sizeof(hdr);
1164         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1165                 return -EFAULT;
1166         pp->busy = 0;
1167
1168         return rc;
1169 }
1170
1171
1172 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1173                                char __user *buf, size_t count)
1174 {
1175         /* Not implemented */
1176         msleep_interruptible(1000);
1177         return 0;
1178 }
1179
1180
1181 static ssize_t smu_read(struct file *file, char __user *buf,
1182                         size_t count, loff_t *ppos)
1183 {
1184         struct smu_private *pp = file->private_data;
1185
1186         if (pp->mode == smu_file_commands)
1187                 return smu_read_command(file, pp, buf, count);
1188         if (pp->mode == smu_file_events)
1189                 return smu_read_events(file, pp, buf, count);
1190
1191         return -EBADFD;
1192 }
1193
1194 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1195 {
1196         struct smu_private *pp = file->private_data;
1197         unsigned int mask = 0;
1198         unsigned long flags;
1199
1200         if (pp == 0)
1201                 return 0;
1202
1203         if (pp->mode == smu_file_commands) {
1204                 poll_wait(file, &pp->wait, wait);
1205
1206                 spin_lock_irqsave(&pp->lock, flags);
1207                 if (pp->busy && pp->cmd.status != 1)
1208                         mask |= POLLIN;
1209                 spin_unlock_irqrestore(&pp->lock, flags);
1210         } if (pp->mode == smu_file_events) {
1211                 /* Not yet implemented */
1212         }
1213         return mask;
1214 }
1215
1216 static int smu_release(struct inode *inode, struct file *file)
1217 {
1218         struct smu_private *pp = file->private_data;
1219         unsigned long flags;
1220         unsigned int busy;
1221
1222         if (pp == 0)
1223                 return 0;
1224
1225         file->private_data = NULL;
1226
1227         /* Mark file as closing to avoid races with new request */
1228         spin_lock_irqsave(&pp->lock, flags);
1229         pp->mode = smu_file_closing;
1230         busy = pp->busy;
1231
1232         /* Wait for any pending request to complete */
1233         if (busy && pp->cmd.status == 1) {
1234                 DECLARE_WAITQUEUE(wait, current);
1235
1236                 add_wait_queue(&pp->wait, &wait);
1237                 for (;;) {
1238                         set_current_state(TASK_UNINTERRUPTIBLE);
1239                         if (pp->cmd.status != 1)
1240                                 break;
1241                         spin_lock_irqsave(&pp->lock, flags);
1242                         schedule();
1243                         spin_unlock_irqrestore(&pp->lock, flags);
1244                 }
1245                 set_current_state(TASK_RUNNING);
1246                 remove_wait_queue(&pp->wait, &wait);
1247         }
1248         spin_unlock_irqrestore(&pp->lock, flags);
1249
1250         spin_lock_irqsave(&smu_clist_lock, flags);
1251         list_del(&pp->list);
1252         spin_unlock_irqrestore(&smu_clist_lock, flags);
1253         kfree(pp);
1254
1255         return 0;
1256 }
1257
1258
1259 static struct file_operations smu_device_fops = {
1260         .llseek         = no_llseek,
1261         .read           = smu_read,
1262         .write          = smu_write,
1263         .poll           = smu_fpoll,
1264         .open           = smu_open,
1265         .release        = smu_release,
1266 };
1267
1268 static struct miscdevice pmu_device = {
1269         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1270 };
1271
1272 static int smu_device_init(void)
1273 {
1274         if (!smu)
1275                 return -ENODEV;
1276         if (misc_register(&pmu_device) < 0)
1277                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1278         return 0;
1279 }
1280 device_initcall(smu_device_init);