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 { printk(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 static void smu_i2c_retry(unsigned long data);
  98
  99 /*
 100  * SMU driver low level stuff
 101  */
 102
 103 static void smu_start_cmd(void)
 104 {
 105         unsigned long faddr, fend;
 106         struct smu_cmd *cmd;
 107
 108         if (list_empty(&smu->cmd_list))
 109                 return;
 110
 111         /* Fetch first command in queue */
 112         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 113         smu->cmd_cur = cmd;
 114         list_del(&cmd->link);
 115
 116         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 117                 cmd->data_len);
 118         DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 119                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 120                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 121                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 122                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 123
 124         /* Fill the SMU command buffer */
 125         smu->cmd_buf->cmd = cmd->cmd;
 126         smu->cmd_buf->length = cmd->data_len;
 127         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 128
 129         /* Flush command and data to RAM */
 130         faddr = (unsigned long)smu->cmd_buf;
 131         fend = faddr + smu->cmd_buf->length + 2;
 132         flush_inval_dcache_range(faddr, fend);
 133
 134         /* This isn't exactly a DMA mapping here, I suspect
 135          * the SMU is actually communicating with us via i2c to the
 136          * northbridge or the CPU to access RAM.
 137          */
 138         writel(smu->cmd_buf_abs, smu->db_buf);
 139
 140         /* Ring the SMU doorbell */
 141         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 142 }
 143
 144
 145 static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs)
 146 {
 147         unsigned long flags;
 148         struct smu_cmd *cmd;
 149         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 150         void *misc = NULL;
 151         u8 gpio;
 152         int rc = 0;
 153
 154         /* SMU completed the command, well, we hope, let's make sure
 155          * of it
 156          */
 157         spin_lock_irqsave(&smu->lock, flags);
 158
 159         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 160         if ((gpio & 7) != 7) {
 161                 spin_unlock_irqrestore(&smu->lock, flags);
 162                 return IRQ_HANDLED;
 163         }
 164
 165         cmd = smu->cmd_cur;
 166         smu->cmd_cur = NULL;
 167         if (cmd == NULL)
 168                 goto bail;
 169
 170         if (rc == 0) {
 171                 unsigned long faddr;
 172                 int reply_len;
 173                 u8 ack;
 174
 175                 /* CPU might have brought back the cache line, so we need
 176                  * to flush again before peeking at the SMU response. We
 177                  * flush the entire buffer for now as we haven't read the
 178                  * reply lenght (it's only 2 cache lines anyway)
 179                  */
 180                 faddr = (unsigned long)smu->cmd_buf;
 181                 flush_inval_dcache_range(faddr, faddr + 256);
 182
 183                 /* Now check ack */
 184                 ack = (~cmd->cmd) & 0xff;
 185                 if (ack != smu->cmd_buf->cmd) {
 186                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 187                                 ack, smu->cmd_buf->cmd);
 188                         rc = -EIO;
 189                 }
 190                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 191                 DPRINTK("SMU: reply len: %d\n", reply_len);
 192                 if (reply_len > cmd->reply_len) {
 193                         printk(KERN_WARNING "SMU: reply buffer too small,"
 194                                "got %d bytes for a %d bytes buffer\n",
 195                                reply_len, cmd->reply_len);
 196                         reply_len = cmd->reply_len;
 197                 }
 198                 cmd->reply_len = reply_len;
 199                 if (cmd->reply_buf && reply_len)
 200                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 201         }
 202
 203         /* Now complete the command. Write status last in order as we lost
 204          * ownership of the command structure as soon as it's no longer -1
 205          */
 206         done = cmd->done;
 207         misc = cmd->misc;
 208         mb();
 209         cmd->status = rc;
 210  bail:
 211         /* Start next command if any */
 212         smu_start_cmd();
 213         spin_unlock_irqrestore(&smu->lock, flags);
 214
 215         /* Call command completion handler if any */
 216         if (done)
 217                 done(cmd, misc);
 218
 219         /* It's an edge interrupt, nothing to do */
 220         return IRQ_HANDLED;
 221 }
 222
 223
 224 static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
 225 {
 226         /* I don't quite know what to do with this one, we seem to never
 227          * receive it, so I suspect we have to arm it someway in the SMU
 228          * to start getting events that way.
 229          */
 230
 231         printk(KERN_INFO "SMU: message interrupt !\n");
 232
 233         /* It's an edge interrupt, nothing to do */
 234         return IRQ_HANDLED;
 235 }
 236
 237
 238 /*
 239  * Queued command management.
 240  *
 241  */
 242
 243 int smu_queue_cmd(struct smu_cmd *cmd)
 244 {
 245         unsigned long flags;
 246
 247         if (smu == NULL)
 248                 return -ENODEV;
 249         if (cmd->data_len > SMU_MAX_DATA ||
 250             cmd->reply_len > SMU_MAX_DATA)
 251                 return -EINVAL;
 252
 253         cmd->status = 1;
 254         spin_lock_irqsave(&smu->lock, flags);
 255         list_add_tail(&cmd->link, &smu->cmd_list);
 256         if (smu->cmd_cur == NULL)
 257                 smu_start_cmd();
 258         spin_unlock_irqrestore(&smu->lock, flags);
 259
 260         return 0;
 261 }
 262 EXPORT_SYMBOL(smu_queue_cmd);
 263
 264
 265 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 266                      unsigned int data_len,
 267                      void (*done)(struct smu_cmd *cmd, void *misc),
 268                      void *misc, ...)
 269 {
 270         struct smu_cmd *cmd = &scmd->cmd;
 271         va_list list;
 272         int i;
 273
 274         if (data_len > sizeof(scmd->buffer))
 275                 return -EINVAL;
 276
 277         memset(scmd, 0, sizeof(*scmd));
 278         cmd->cmd = command;
 279         cmd->data_len = data_len;
 280         cmd->data_buf = scmd->buffer;
 281         cmd->reply_len = sizeof(scmd->buffer);
 282         cmd->reply_buf = scmd->buffer;
 283         cmd->done = done;
 284         cmd->misc = misc;
 285
 286         va_start(list, misc);
 287         for (i = 0; i < data_len; ++i)
 288                 scmd->buffer[i] = (u8)va_arg(list, int);
 289         va_end(list);
 290
 291         return smu_queue_cmd(cmd);
 292 }
 293 EXPORT_SYMBOL(smu_queue_simple);
 294
 295
 296 void smu_poll(void)
 297 {
 298         u8 gpio;
 299
 300         if (smu == NULL)
 301                 return;
 302
 303         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 304         if ((gpio & 7) == 7)
 305                 smu_db_intr(smu->db_irq, smu, NULL);
 306 }
 307 EXPORT_SYMBOL(smu_poll);
 308
 309
 310 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 311 {
 312         struct completion *comp = misc;
 313
 314         complete(comp);
 315 }
 316 EXPORT_SYMBOL(smu_done_complete);
 317
 318
 319 void smu_spinwait_cmd(struct smu_cmd *cmd)
 320 {
 321         while(cmd->status == 1)
 322                 smu_poll();
 323 }
 324 EXPORT_SYMBOL(smu_spinwait_cmd);
 325
 326
 327 /* RTC low level commands */
 328 static inline int bcd2hex (int n)
 329 {
 330         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 331 }
 332
 333
 334 static inline int hex2bcd (int n)
 335 {
 336         return ((n / 10) << 4) + (n % 10);
 337 }
 338
 339
 340 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 341                                         struct rtc_time *time)
 342 {
 343         cmd_buf->cmd = 0x8e;
 344         cmd_buf->length = 8;
 345         cmd_buf->data[0] = 0x80;
 346         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 347         cmd_buf->data[2] = hex2bcd(time->tm_min);
 348         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 349         cmd_buf->data[4] = time->tm_wday;
 350         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 351         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 352         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 353 }
 354
 355
 356 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 357 {
 358         struct smu_simple_cmd cmd;
 359         int rc;
 360
 361         if (smu == NULL)
 362                 return -ENODEV;
 363
 364         memset(time, 0, sizeof(struct rtc_time));
 365         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 366                               SMU_CMD_RTC_GET_DATETIME);
 367         if (rc)
 368                 return rc;
 369         smu_spinwait_simple(&cmd);
 370
 371         time->tm_sec = bcd2hex(cmd.buffer[0]);
 372         time->tm_min = bcd2hex(cmd.buffer[1]);
 373         time->tm_hour = bcd2hex(cmd.buffer[2]);
 374         time->tm_wday = bcd2hex(cmd.buffer[3]);
 375         time->tm_mday = bcd2hex(cmd.buffer[4]);
 376         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 377         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 378
 379         return 0;
 380 }
 381
 382
 383 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 384 {
 385         struct smu_simple_cmd cmd;
 386         int rc;
 387
 388         if (smu == NULL)
 389                 return -ENODEV;
 390
 391         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 392                               SMU_CMD_RTC_SET_DATETIME,
 393                               hex2bcd(time->tm_sec),
 394                               hex2bcd(time->tm_min),
 395                               hex2bcd(time->tm_hour),
 396                               time->tm_wday,
 397                               hex2bcd(time->tm_mday),
 398                               hex2bcd(time->tm_mon) + 1,
 399                               hex2bcd(time->tm_year - 100));
 400         if (rc)
 401                 return rc;
 402         smu_spinwait_simple(&cmd);
 403
 404         return 0;
 405 }
 406
 407
 408 void smu_shutdown(void)
 409 {
 410         struct smu_simple_cmd cmd;
 411
 412         if (smu == NULL)
 413                 return;
 414
 415         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 416                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 417                 return;
 418         smu_spinwait_simple(&cmd);
 419         for (;;)
 420                 ;
 421 }
 422
 423
 424 void smu_restart(void)
 425 {
 426         struct smu_simple_cmd cmd;
 427
 428         if (smu == NULL)
 429                 return;
 430
 431         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 432                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 433                 return;
 434         smu_spinwait_simple(&cmd);
 435         for (;;)
 436                 ;
 437 }
 438
 439
 440 int smu_present(void)
 441 {
 442         return smu != NULL;
 443 }
 444 EXPORT_SYMBOL(smu_present);
 445
 446
 447 int __init smu_init (void)
 448 {
 449         struct device_node *np;
 450         u32 *data;
 451
 452         np = of_find_node_by_type(NULL, "smu");
 453         if (np == NULL)
 454                 return -ENODEV;
 455
 456         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
 457
 458         if (smu_cmdbuf_abs == 0) {
 459                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 460                 return -EINVAL;
 461         }
 462
 463         smu = alloc_bootmem(sizeof(struct smu_device));
 464         if (smu == NULL)
 465                 return -ENOMEM;
 466         memset(smu, 0, sizeof(*smu));
 467
 468         spin_lock_init(&smu->lock);
 469         INIT_LIST_HEAD(&smu->cmd_list);
 470         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 471         smu->of_node = np;
 472         smu->db_irq = NO_IRQ;
 473         smu->msg_irq = NO_IRQ;
 474
 475         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 476          * 32 bits value safely
 477          */
 478         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 479         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 480
 481         np = of_find_node_by_name(NULL, "smu-doorbell");
 482         if (np == NULL) {
 483                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 484                 goto fail;
 485         }
 486         data = (u32 *)get_property(np, "reg", NULL);
 487         if (data == NULL) {
 488                 of_node_put(np);
 489                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 490                 goto fail;
 491         }
 492
 493         /* Current setup has one doorbell GPIO that does both doorbell
 494          * and ack. GPIOs are at 0x50, best would be to find that out
 495          * in the device-tree though.
 496          */
 497         smu->doorbell = *data;
 498         if (smu->doorbell < 0x50)
 499                 smu->doorbell += 0x50;
 500         if (np->n_intrs > 0)
 501                 smu->db_irq = np->intrs[0].line;
 502
 503         of_node_put(np);
 504
 505         /* Now look for the smu-interrupt GPIO */
 506         do {
 507                 np = of_find_node_by_name(NULL, "smu-interrupt");
 508                 if (np == NULL)
 509                         break;
 510                 data = (u32 *)get_property(np, "reg", NULL);
 511                 if (data == NULL) {
 512                         of_node_put(np);
 513                         break;
 514                 }
 515                 smu->msg = *data;
 516                 if (smu->msg < 0x50)
 517                         smu->msg += 0x50;
 518                 if (np->n_intrs > 0)
 519                         smu->msg_irq = np->intrs[0].line;
 520                 of_node_put(np);
 521         } while(0);
 522
 523         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 524          * device-tree entry giving the address. Best would probably to use
 525          * an offset for K2 base though, but let's do it that way for now.
 526          */
 527         smu->db_buf = ioremap(0x8000860c, 0x1000);
 528         if (smu->db_buf == NULL) {
 529                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 530                 goto fail;
 531         }
 532
 533         sys_ctrler = SYS_CTRLER_SMU;
 534         return 0;
 535
 536  fail:
 537         smu = NULL;
 538         return -ENXIO;
 539
 540 }
 541
 542
 543 static int smu_late_init(void)
 544 {
 545         if (!smu)
 546                 return 0;
 547
 548         init_timer(&smu->i2c_timer);
 549         smu->i2c_timer.function = smu_i2c_retry;
 550         smu->i2c_timer.data = (unsigned long)smu;
 551
 552         /*
 553          * Try to request the interrupts
 554          */
 555
 556         if (smu->db_irq != NO_IRQ) {
 557                 if (request_irq(smu->db_irq, smu_db_intr,
 558                                 SA_SHIRQ, "SMU doorbell", smu) < 0) {
 559                         printk(KERN_WARNING "SMU: can't "
 560                                "request interrupt %d\n",
 561                                smu->db_irq);
 562                         smu->db_irq = NO_IRQ;
 563                 }
 564         }
 565
 566         if (smu->msg_irq != NO_IRQ) {
 567                 if (request_irq(smu->msg_irq, smu_msg_intr,
 568                                 SA_SHIRQ, "SMU message", smu) < 0) {
 569                         printk(KERN_WARNING "SMU: can't "
 570                                "request interrupt %d\n",
 571                                smu->msg_irq);
 572                         smu->msg_irq = NO_IRQ;
 573                 }
 574         }
 575
 576         return 0;
 577 }
 578 /* This has to be before arch_initcall as the low i2c stuff relies on the
 579  * above having been done before we reach arch_initcalls
 580  */
 581 core_initcall(smu_late_init);
 582
 583 /*
 584  * sysfs visibility
 585  */
 586
 587 static void smu_expose_childs(void *unused)
 588 {
 589         struct device_node *np;
 590
 591         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 592                 if (device_is_compatible(np, "smu-sensors"))
 593                         of_platform_device_create(np, "smu-sensors",
 594                                                   &smu->of_dev->dev);
 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         /*
 633          * Due to sysfs bogosity, a sysdev is not a real device, so
 634          * we should in fact create both if we want sysdev semantics
 635          * for power management.
 636          * For now, we don't power manage machines with an SMU chip,
 637          * I'm a bit too far from figuring out how that works with those
 638          * new chipsets, but that will come back and bite us
 639          */
 640         of_register_driver(&smu_of_platform_driver);
 641         return 0;
 642 }
 643
 644 device_initcall(smu_init_sysfs);
 645
 646 struct of_device *smu_get_ofdev(void)
 647 {
 648         if (!smu)
 649                 return NULL;
 650         return smu->of_dev;
 651 }
 652
 653 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 654
 655 /*
 656  * i2c interface
 657  */
 658
 659 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 660 {
 661         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 662         void *misc = cmd->misc;
 663         unsigned long flags;
 664
 665         /* Check for read case */
 666         if (!fail && cmd->read) {
 667                 if (cmd->pdata[0] < 1)
 668                         fail = 1;
 669                 else
 670                         memcpy(cmd->info.data, &cmd->pdata[1],
 671                                cmd->info.datalen);
 672         }
 673
 674         DPRINTK("SMU: completing, success: %d\n", !fail);
 675
 676         /* Update status and mark no pending i2c command with lock
 677          * held so nobody comes in while we dequeue an eventual
 678          * pending next i2c command
 679          */
 680         spin_lock_irqsave(&smu->lock, flags);
 681         smu->cmd_i2c_cur = NULL;
 682         wmb();
 683         cmd->status = fail ? -EIO : 0;
 684
 685         /* Is there another i2c command waiting ? */
 686         if (!list_empty(&smu->cmd_i2c_list)) {
 687                 struct smu_i2c_cmd *newcmd;
 688
 689                 /* Fetch it, new current, remove from list */
 690                 newcmd = list_entry(smu->cmd_i2c_list.next,
 691                                     struct smu_i2c_cmd, link);
 692                 smu->cmd_i2c_cur = newcmd;
 693                 list_del(&cmd->link);
 694
 695                 /* Queue with low level smu */
 696                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 697                 if (smu->cmd_cur == NULL)
 698                         smu_start_cmd();
 699         }
 700         spin_unlock_irqrestore(&smu->lock, flags);
 701
 702         /* Call command completion handler if any */
 703         if (done)
 704                 done(cmd, misc);
 705
 706 }
 707
 708
 709 static void smu_i2c_retry(unsigned long data)
 710 {
 711         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 712
 713         DPRINTK("SMU: i2c failure, requeuing...\n");
 714
 715         /* requeue command simply by resetting reply_len */
 716         cmd->pdata[0] = 0xff;
 717         cmd->scmd.reply_len = sizeof(cmd->pdata);
 718         smu_queue_cmd(&cmd->scmd);
 719 }
 720
 721
 722 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 723 {
 724         struct smu_i2c_cmd      *cmd = misc;
 725         int                     fail = 0;
 726
 727         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 728                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 729
 730         /* Check for possible status */
 731         if (scmd->status < 0)
 732                 fail = 1;
 733         else if (cmd->read) {
 734                 if (cmd->stage == 0)
 735                         fail = cmd->pdata[0] != 0;
 736                 else
 737                         fail = cmd->pdata[0] >= 0x80;
 738         } else {
 739                 fail = cmd->pdata[0] != 0;
 740         }
 741
 742         /* Handle failures by requeuing command, after 5ms interval
 743          */
 744         if (fail && --cmd->retries > 0) {
 745                 DPRINTK("SMU: i2c failure, starting timer...\n");
 746                 BUG_ON(cmd != smu->cmd_i2c_cur);
 747                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 748                 return;
 749         }
 750
 751         /* If failure or stage 1, command is complete */
 752         if (fail || cmd->stage != 0) {
 753                 smu_i2c_complete_command(cmd, fail);
 754                 return;
 755         }
 756
 757         DPRINTK("SMU: going to stage 1\n");
 758
 759         /* Ok, initial command complete, now poll status */
 760         scmd->reply_buf = cmd->pdata;
 761         scmd->reply_len = sizeof(cmd->pdata);
 762         scmd->data_buf = cmd->pdata;
 763         scmd->data_len = 1;
 764         cmd->pdata[0] = 0;
 765         cmd->stage = 1;
 766         cmd->retries = 20;
 767         smu_queue_cmd(scmd);
 768 }
 769
 770
 771 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 772 {
 773         unsigned long flags;
 774
 775         if (smu == NULL)
 776                 return -ENODEV;
 777
 778         /* Fill most fields of scmd */
 779         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 780         cmd->scmd.done = smu_i2c_low_completion;
 781         cmd->scmd.misc = cmd;
 782         cmd->scmd.reply_buf = cmd->pdata;
 783         cmd->scmd.reply_len = sizeof(cmd->pdata);
 784         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 785         cmd->scmd.status = 1;
 786         cmd->stage = 0;
 787         cmd->pdata[0] = 0xff;
 788         cmd->retries = 20;
 789         cmd->status = 1;
 790
 791         /* Check transfer type, sanitize some "info" fields
 792          * based on transfer type and do more checking
 793          */
 794         cmd->info.caddr = cmd->info.devaddr;
 795         cmd->read = cmd->info.devaddr & 0x01;
 796         switch(cmd->info.type) {
 797         case SMU_I2C_TRANSFER_SIMPLE:
 798                 memset(&cmd->info.sublen, 0, 4);
 799                 break;
 800         case SMU_I2C_TRANSFER_COMBINED:
 801                 cmd->info.devaddr &= 0xfe;
 802         case SMU_I2C_TRANSFER_STDSUB:
 803                 if (cmd->info.sublen > 3)
 804                         return -EINVAL;
 805                 break;
 806         default:
 807                 return -EINVAL;
 808         }
 809
 810         /* Finish setting up command based on transfer direction
 811          */
 812         if (cmd->read) {
 813                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 814                         return -EINVAL;
 815                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 816                 cmd->scmd.data_len = 9;
 817         } else {
 818                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 819                         return -EINVAL;
 820                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 821         }
 822
 823         DPRINTK("SMU: i2c enqueuing command\n");
 824         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 825                 cmd->read ? "read" : "write", cmd->info.datalen,
 826                 cmd->info.bus, cmd->info.caddr,
 827                 cmd->info.subaddr[0], cmd->info.type);
 828
 829
 830         /* Enqueue command in i2c list, and if empty, enqueue also in
 831          * main command list
 832          */
 833         spin_lock_irqsave(&smu->lock, flags);
 834         if (smu->cmd_i2c_cur == NULL) {
 835                 smu->cmd_i2c_cur = cmd;
 836                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 837                 if (smu->cmd_cur == NULL)
 838                         smu_start_cmd();
 839         } else
 840                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 841         spin_unlock_irqrestore(&smu->lock, flags);
 842
 843         return 0;
 844 }
 845
 846 /*
 847  * Handling of "partitions"
 848  */
 849
 850 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 851 {
 852         DECLARE_COMPLETION(comp);
 853         unsigned int chunk;
 854         struct smu_cmd cmd;
 855         int rc;
 856         u8 params[8];
 857
 858         /* We currently use a chunk size of 0xe. We could check the
 859          * SMU firmware version and use bigger sizes though
 860          */
 861         chunk = 0xe;
 862
 863         while (len) {
 864                 unsigned int clen = min(len, chunk);
 865
 866                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 867                 cmd.data_len = 7;
 868                 cmd.data_buf = params;
 869                 cmd.reply_len = chunk;
 870                 cmd.reply_buf = dest;
 871                 cmd.done = smu_done_complete;
 872                 cmd.misc = &comp;
 873                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 874                 params[1] = 0x4;
 875                 *((u32 *)&params[2]) = addr;
 876                 params[6] = clen;
 877
 878                 rc = smu_queue_cmd(&cmd);
 879                 if (rc)
 880                         return rc;
 881                 wait_for_completion(&comp);
 882                 if (cmd.status != 0)
 883                         return rc;
 884                 if (cmd.reply_len != clen) {
 885                         printk(KERN_DEBUG "SMU: short read in "
 886                                "smu_read_datablock, got: %d, want: %d\n",
 887                                cmd.reply_len, clen);
 888                         return -EIO;
 889                 }
 890                 len -= clen;
 891                 addr += clen;
 892                 dest += clen;
 893         }
 894         return 0;
 895 }
 896
 897 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 898 {
 899         DECLARE_COMPLETION(comp);
 900         struct smu_simple_cmd cmd;
 901         unsigned int addr, len, tlen;
 902         struct smu_sdbp_header *hdr;
 903         struct property *prop;
 904
 905         /* First query the partition info */
 906         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 907         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 908                          smu_done_complete, &comp,
 909                          SMU_CMD_PARTITION_LATEST, id);
 910         wait_for_completion(&comp);
 911         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 912                 cmd.cmd.status, cmd.cmd.reply_len);
 913
 914         /* Partition doesn't exist (or other error) */
 915         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 916                 return NULL;
 917
 918         /* Fetch address and length from reply */
 919         addr = *((u16 *)cmd.buffer);
 920         len = cmd.buffer[3] << 2;
 921         /* Calucluate total length to allocate, including the 17 bytes
 922          * for "sdb-partition-XX" that we append at the end of the buffer
 923          */
 924         tlen = sizeof(struct property) + len + 18;
 925
 926         prop = kcalloc(tlen, 1, GFP_KERNEL);
 927         if (prop == NULL)
 928                 return NULL;
 929         hdr = (struct smu_sdbp_header *)(prop + 1);
 930         prop->name = ((char *)prop) + tlen - 18;
 931         sprintf(prop->name, "sdb-partition-%02x", id);
 932         prop->length = len;
 933         prop->value = (unsigned char *)hdr;
 934         prop->next = NULL;
 935
 936         /* Read the datablock */
 937         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 938                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 939                        "partition %02x !\n", id);
 940                 goto failure;
 941         }
 942
 943         /* Got it, check a few things and create the property */
 944         if (hdr->id != id) {
 945                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 946                        "%02x !\n", id, hdr->id);
 947                 goto failure;
 948         }
 949         if (prom_add_property(smu->of_node, prop)) {
 950                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 951                        "property !\n", id);
 952                 goto failure;
 953         }
 954
 955         return hdr;
 956  failure:
 957         kfree(prop);
 958         return NULL;
 959 }
 960
 961 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
 962  * when interruptible is 1
 963  */
 964 struct smu_sdbp_header *__smu_get_sdb_partition(int id, unsigned int *size,
 965                                                 int interruptible)
 966 {
 967         char pname[32];
 968         struct smu_sdbp_header *part;
 969
 970         if (!smu)
 971                 return NULL;
 972
 973         sprintf(pname, "sdb-partition-%02x", id);
 974
 975         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
 976
 977         if (interruptible) {
 978                 int rc;
 979                 rc = down_interruptible(&smu_part_access);
 980                 if (rc)
 981                         return ERR_PTR(rc);
 982         } else
 983                 down(&smu_part_access);
 984
 985         part = (struct smu_sdbp_header *)get_property(smu->of_node,
 986                                                       pname, size);
 987         if (part == NULL) {
 988                 DPRINTK("trying to extract from SMU ...\n");
 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);