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/types.h>
  23 #include <linux/kernel.h>
  24 #include <linux/device.h>
  25 #include <linux/dmapool.h>
  26 #include <linux/bootmem.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/highmem.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/rtc.h>
  32 #include <linux/completion.h>
  33 #include <linux/miscdevice.h>
  34 #include <linux/delay.h>
  35 #include <linux/sysdev.h>
  36 #include <linux/poll.h>
  37 #include <linux/mutex.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 DEFINE_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         smu->db_irq = irq_of_parse_and_map(np, 0);
 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                 smu->msg_irq = irq_of_parse_and_map(np, 0);
 518                 of_node_put(np);
 519         } while(0);
 520
 521         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 522          * device-tree entry giving the address. Best would probably to use
 523          * an offset for K2 base though, but let's do it that way for now.
 524          */
 525         smu->db_buf = ioremap(0x8000860c, 0x1000);
 526         if (smu->db_buf == NULL) {
 527                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 528                 goto fail;
 529         }
 530
 531         sys_ctrler = SYS_CTRLER_SMU;
 532         return 0;
 533
 534  fail:
 535         smu = NULL;
 536         return -ENXIO;
 537
 538 }
 539
 540
 541 static int smu_late_init(void)
 542 {
 543         if (!smu)
 544                 return 0;
 545
 546         init_timer(&smu->i2c_timer);
 547         smu->i2c_timer.function = smu_i2c_retry;
 548         smu->i2c_timer.data = (unsigned long)smu;
 549
 550         /*
 551          * Try to request the interrupts
 552          */
 553
 554         if (smu->db_irq != NO_IRQ) {
 555                 if (request_irq(smu->db_irq, smu_db_intr,
 556                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 557                         printk(KERN_WARNING "SMU: can't "
 558                                "request interrupt %d\n",
 559                                smu->db_irq);
 560                         smu->db_irq = NO_IRQ;
 561                 }
 562         }
 563
 564         if (smu->msg_irq != NO_IRQ) {
 565                 if (request_irq(smu->msg_irq, smu_msg_intr,
 566                                 IRQF_SHARED, "SMU message", smu) < 0) {
 567                         printk(KERN_WARNING "SMU: can't "
 568                                "request interrupt %d\n",
 569                                smu->msg_irq);
 570                         smu->msg_irq = NO_IRQ;
 571                 }
 572         }
 573
 574         return 0;
 575 }
 576 /* This has to be before arch_initcall as the low i2c stuff relies on the
 577  * above having been done before we reach arch_initcalls
 578  */
 579 core_initcall(smu_late_init);
 580
 581 /*
 582  * sysfs visibility
 583  */
 584
 585 static void smu_expose_childs(void *unused)
 586 {
 587         struct device_node *np;
 588
 589         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 590                 if (device_is_compatible(np, "smu-sensors"))
 591                         of_platform_device_create(np, "smu-sensors",
 592                                                   &smu->of_dev->dev);
 593 }
 594
 595 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
 596
 597 static int smu_platform_probe(struct of_device* dev,
 598                               const struct of_device_id *match)
 599 {
 600         if (!smu)
 601                 return -ENODEV;
 602         smu->of_dev = dev;
 603
 604         /*
 605          * Ok, we are matched, now expose all i2c busses. We have to defer
 606          * that unfortunately or it would deadlock inside the device model
 607          */
 608         schedule_work(&smu_expose_childs_work);
 609
 610         return 0;
 611 }
 612
 613 static struct of_device_id smu_platform_match[] =
 614 {
 615         {
 616                 .type           = "smu",
 617         },
 618         {},
 619 };
 620
 621 static struct of_platform_driver smu_of_platform_driver =
 622 {
 623         .name           = "smu",
 624         .match_table    = smu_platform_match,
 625         .probe          = smu_platform_probe,
 626 };
 627
 628 static int __init smu_init_sysfs(void)
 629 {
 630         /*
 631          * Due to sysfs bogosity, a sysdev is not a real device, so
 632          * we should in fact create both if we want sysdev semantics
 633          * for power management.
 634          * For now, we don't power manage machines with an SMU chip,
 635          * I'm a bit too far from figuring out how that works with those
 636          * new chipsets, but that will come back and bite us
 637          */
 638         of_register_driver(&smu_of_platform_driver);
 639         return 0;
 640 }
 641
 642 device_initcall(smu_init_sysfs);
 643
 644 struct of_device *smu_get_ofdev(void)
 645 {
 646         if (!smu)
 647                 return NULL;
 648         return smu->of_dev;
 649 }
 650
 651 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 652
 653 /*
 654  * i2c interface
 655  */
 656
 657 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 658 {
 659         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 660         void *misc = cmd->misc;
 661         unsigned long flags;
 662
 663         /* Check for read case */
 664         if (!fail && cmd->read) {
 665                 if (cmd->pdata[0] < 1)
 666                         fail = 1;
 667                 else
 668                         memcpy(cmd->info.data, &cmd->pdata[1],
 669                                cmd->info.datalen);
 670         }
 671
 672         DPRINTK("SMU: completing, success: %d\n", !fail);
 673
 674         /* Update status and mark no pending i2c command with lock
 675          * held so nobody comes in while we dequeue an eventual
 676          * pending next i2c command
 677          */
 678         spin_lock_irqsave(&smu->lock, flags);
 679         smu->cmd_i2c_cur = NULL;
 680         wmb();
 681         cmd->status = fail ? -EIO : 0;
 682
 683         /* Is there another i2c command waiting ? */
 684         if (!list_empty(&smu->cmd_i2c_list)) {
 685                 struct smu_i2c_cmd *newcmd;
 686
 687                 /* Fetch it, new current, remove from list */
 688                 newcmd = list_entry(smu->cmd_i2c_list.next,
 689                                     struct smu_i2c_cmd, link);
 690                 smu->cmd_i2c_cur = newcmd;
 691                 list_del(&cmd->link);
 692
 693                 /* Queue with low level smu */
 694                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 695                 if (smu->cmd_cur == NULL)
 696                         smu_start_cmd();
 697         }
 698         spin_unlock_irqrestore(&smu->lock, flags);
 699
 700         /* Call command completion handler if any */
 701         if (done)
 702                 done(cmd, misc);
 703
 704 }
 705
 706
 707 static void smu_i2c_retry(unsigned long data)
 708 {
 709         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 710
 711         DPRINTK("SMU: i2c failure, requeuing...\n");
 712
 713         /* requeue command simply by resetting reply_len */
 714         cmd->pdata[0] = 0xff;
 715         cmd->scmd.reply_len = sizeof(cmd->pdata);
 716         smu_queue_cmd(&cmd->scmd);
 717 }
 718
 719
 720 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 721 {
 722         struct smu_i2c_cmd      *cmd = misc;
 723         int                     fail = 0;
 724
 725         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 726                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 727
 728         /* Check for possible status */
 729         if (scmd->status < 0)
 730                 fail = 1;
 731         else if (cmd->read) {
 732                 if (cmd->stage == 0)
 733                         fail = cmd->pdata[0] != 0;
 734                 else
 735                         fail = cmd->pdata[0] >= 0x80;
 736         } else {
 737                 fail = cmd->pdata[0] != 0;
 738         }
 739
 740         /* Handle failures by requeuing command, after 5ms interval
 741          */
 742         if (fail && --cmd->retries > 0) {
 743                 DPRINTK("SMU: i2c failure, starting timer...\n");
 744                 BUG_ON(cmd != smu->cmd_i2c_cur);
 745                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 746                 return;
 747         }
 748
 749         /* If failure or stage 1, command is complete */
 750         if (fail || cmd->stage != 0) {
 751                 smu_i2c_complete_command(cmd, fail);
 752                 return;
 753         }
 754
 755         DPRINTK("SMU: going to stage 1\n");
 756
 757         /* Ok, initial command complete, now poll status */
 758         scmd->reply_buf = cmd->pdata;
 759         scmd->reply_len = sizeof(cmd->pdata);
 760         scmd->data_buf = cmd->pdata;
 761         scmd->data_len = 1;
 762         cmd->pdata[0] = 0;
 763         cmd->stage = 1;
 764         cmd->retries = 20;
 765         smu_queue_cmd(scmd);
 766 }
 767
 768
 769 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 770 {
 771         unsigned long flags;
 772
 773         if (smu == NULL)
 774                 return -ENODEV;
 775
 776         /* Fill most fields of scmd */
 777         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 778         cmd->scmd.done = smu_i2c_low_completion;
 779         cmd->scmd.misc = cmd;
 780         cmd->scmd.reply_buf = cmd->pdata;
 781         cmd->scmd.reply_len = sizeof(cmd->pdata);
 782         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 783         cmd->scmd.status = 1;
 784         cmd->stage = 0;
 785         cmd->pdata[0] = 0xff;
 786         cmd->retries = 20;
 787         cmd->status = 1;
 788
 789         /* Check transfer type, sanitize some "info" fields
 790          * based on transfer type and do more checking
 791          */
 792         cmd->info.caddr = cmd->info.devaddr;
 793         cmd->read = cmd->info.devaddr & 0x01;
 794         switch(cmd->info.type) {
 795         case SMU_I2C_TRANSFER_SIMPLE:
 796                 memset(&cmd->info.sublen, 0, 4);
 797                 break;
 798         case SMU_I2C_TRANSFER_COMBINED:
 799                 cmd->info.devaddr &= 0xfe;
 800         case SMU_I2C_TRANSFER_STDSUB:
 801                 if (cmd->info.sublen > 3)
 802                         return -EINVAL;
 803                 break;
 804         default:
 805                 return -EINVAL;
 806         }
 807
 808         /* Finish setting up command based on transfer direction
 809          */
 810         if (cmd->read) {
 811                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 812                         return -EINVAL;
 813                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 814                 cmd->scmd.data_len = 9;
 815         } else {
 816                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 817                         return -EINVAL;
 818                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 819         }
 820
 821         DPRINTK("SMU: i2c enqueuing command\n");
 822         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 823                 cmd->read ? "read" : "write", cmd->info.datalen,
 824                 cmd->info.bus, cmd->info.caddr,
 825                 cmd->info.subaddr[0], cmd->info.type);
 826
 827
 828         /* Enqueue command in i2c list, and if empty, enqueue also in
 829          * main command list
 830          */
 831         spin_lock_irqsave(&smu->lock, flags);
 832         if (smu->cmd_i2c_cur == NULL) {
 833                 smu->cmd_i2c_cur = cmd;
 834                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 835                 if (smu->cmd_cur == NULL)
 836                         smu_start_cmd();
 837         } else
 838                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 839         spin_unlock_irqrestore(&smu->lock, flags);
 840
 841         return 0;
 842 }
 843
 844 /*
 845  * Handling of "partitions"
 846  */
 847
 848 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 849 {
 850         DECLARE_COMPLETION(comp);
 851         unsigned int chunk;
 852         struct smu_cmd cmd;
 853         int rc;
 854         u8 params[8];
 855
 856         /* We currently use a chunk size of 0xe. We could check the
 857          * SMU firmware version and use bigger sizes though
 858          */
 859         chunk = 0xe;
 860
 861         while (len) {
 862                 unsigned int clen = min(len, chunk);
 863
 864                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 865                 cmd.data_len = 7;
 866                 cmd.data_buf = params;
 867                 cmd.reply_len = chunk;
 868                 cmd.reply_buf = dest;
 869                 cmd.done = smu_done_complete;
 870                 cmd.misc = &comp;
 871                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 872                 params[1] = 0x4;
 873                 *((u32 *)&params[2]) = addr;
 874                 params[6] = clen;
 875
 876                 rc = smu_queue_cmd(&cmd);
 877                 if (rc)
 878                         return rc;
 879                 wait_for_completion(&comp);
 880                 if (cmd.status != 0)
 881                         return rc;
 882                 if (cmd.reply_len != clen) {
 883                         printk(KERN_DEBUG "SMU: short read in "
 884                                "smu_read_datablock, got: %d, want: %d\n",
 885                                cmd.reply_len, clen);
 886                         return -EIO;
 887                 }
 888                 len -= clen;
 889                 addr += clen;
 890                 dest += clen;
 891         }
 892         return 0;
 893 }
 894
 895 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 896 {
 897         DECLARE_COMPLETION(comp);
 898         struct smu_simple_cmd cmd;
 899         unsigned int addr, len, tlen;
 900         struct smu_sdbp_header *hdr;
 901         struct property *prop;
 902
 903         /* First query the partition info */
 904         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 905         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 906                          smu_done_complete, &comp,
 907                          SMU_CMD_PARTITION_LATEST, id);
 908         wait_for_completion(&comp);
 909         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 910                 cmd.cmd.status, cmd.cmd.reply_len);
 911
 912         /* Partition doesn't exist (or other error) */
 913         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 914                 return NULL;
 915
 916         /* Fetch address and length from reply */
 917         addr = *((u16 *)cmd.buffer);
 918         len = cmd.buffer[3] << 2;
 919         /* Calucluate total length to allocate, including the 17 bytes
 920          * for "sdb-partition-XX" that we append at the end of the buffer
 921          */
 922         tlen = sizeof(struct property) + len + 18;
 923
 924         prop = kcalloc(tlen, 1, GFP_KERNEL);
 925         if (prop == NULL)
 926                 return NULL;
 927         hdr = (struct smu_sdbp_header *)(prop + 1);
 928         prop->name = ((char *)prop) + tlen - 18;
 929         sprintf(prop->name, "sdb-partition-%02x", id);
 930         prop->length = len;
 931         prop->value = (unsigned char *)hdr;
 932         prop->next = NULL;
 933
 934         /* Read the datablock */
 935         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 936                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 937                        "partition %02x !\n", id);
 938                 goto failure;
 939         }
 940
 941         /* Got it, check a few things and create the property */
 942         if (hdr->id != id) {
 943                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 944                        "%02x !\n", id, hdr->id);
 945                 goto failure;
 946         }
 947         if (prom_add_property(smu->of_node, prop)) {
 948                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 949                        "property !\n", id);
 950                 goto failure;
 951         }
 952
 953         return hdr;
 954  failure:
 955         kfree(prop);
 956         return NULL;
 957 }
 958
 959 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
 960  * when interruptible is 1
 961  */
 962 struct smu_sdbp_header *__smu_get_sdb_partition(int id, unsigned int *size,
 963                                                 int interruptible)
 964 {
 965         char pname[32];
 966         struct smu_sdbp_header *part;
 967
 968         if (!smu)
 969                 return NULL;
 970
 971         sprintf(pname, "sdb-partition-%02x", id);
 972
 973         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
 974
 975         if (interruptible) {
 976                 int rc;
 977                 rc = mutex_lock_interruptible(&smu_part_access);
 978                 if (rc)
 979                         return ERR_PTR(rc);
 980         } else
 981                 mutex_lock(&smu_part_access);
 982
 983         part = (struct smu_sdbp_header *)get_property(smu->of_node,
 984                                                       pname, size);
 985         if (part == NULL) {
 986                 DPRINTK("trying to extract from SMU ...\n");
 987                 part = smu_create_sdb_partition(id);
 988                 if (part != NULL && size)
 989                         *size = part->len << 2;
 990         }
 991         mutex_unlock(&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);