git.oblomov.eu Git - linux-2.6/blob - 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 "0.6"
  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
  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 ...\n",
 117                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 118                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3]);
 119
 120         /* Fill the SMU command buffer */
 121         smu->cmd_buf->cmd = cmd->cmd;
 122         smu->cmd_buf->length = cmd->data_len;
 123         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 124
 125         /* Flush command and data to RAM */
 126         faddr = (unsigned long)smu->cmd_buf;
 127         fend = faddr + smu->cmd_buf->length + 2;
 128         flush_inval_dcache_range(faddr, fend);
 129
 130         /* This isn't exactly a DMA mapping here, I suspect
 131          * the SMU is actually communicating with us via i2c to the
 132          * northbridge or the CPU to access RAM.
 133          */
 134         writel(smu->cmd_buf_abs, smu->db_buf);
 135
 136         /* Ring the SMU doorbell */
 137         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 138 }
 139
 140
 141 static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs)
 142 {
 143         unsigned long flags;
 144         struct smu_cmd *cmd;
 145         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 146         void *misc = NULL;
 147         u8 gpio;
 148         int rc = 0;
 149
 150         /* SMU completed the command, well, we hope, let's make sure
 151          * of it
 152          */
 153         spin_lock_irqsave(&smu->lock, flags);
 154
 155         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 156         if ((gpio & 7) != 7) {
 157                 spin_unlock_irqrestore(&smu->lock, flags);
 158                 return IRQ_HANDLED;
 159         }
 160
 161         cmd = smu->cmd_cur;
 162         smu->cmd_cur = NULL;
 163         if (cmd == NULL)
 164                 goto bail;
 165
 166         if (rc == 0) {
 167                 unsigned long faddr;
 168                 int reply_len;
 169                 u8 ack;
 170
 171                 /* CPU might have brought back the cache line, so we need
 172                  * to flush again before peeking at the SMU response. We
 173                  * flush the entire buffer for now as we haven't read the
 174                  * reply lenght (it's only 2 cache lines anyway)
 175                  */
 176                 faddr = (unsigned long)smu->cmd_buf;
 177                 flush_inval_dcache_range(faddr, faddr + 256);
 178
 179                 /* Now check ack */
 180                 ack = (~cmd->cmd) & 0xff;
 181                 if (ack != smu->cmd_buf->cmd) {
 182                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 183                                 ack, smu->cmd_buf->cmd);
 184                         rc = -EIO;
 185                 }
 186                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 187                 DPRINTK("SMU: reply len: %d\n", reply_len);
 188                 if (reply_len > cmd->reply_len) {
 189                         printk(KERN_WARNING "SMU: reply buffer too small,"
 190                                "got %d bytes for a %d bytes buffer\n",
 191                                reply_len, cmd->reply_len);
 192                         reply_len = cmd->reply_len;
 193                 }
 194                 cmd->reply_len = reply_len;
 195                 if (cmd->reply_buf && reply_len)
 196                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 197         }
 198
 199         /* Now complete the command. Write status last in order as we lost
 200          * ownership of the command structure as soon as it's no longer -1
 201          */
 202         done = cmd->done;
 203         misc = cmd->misc;
 204         mb();
 205         cmd->status = rc;
 206  bail:
 207         /* Start next command if any */
 208         smu_start_cmd();
 209         spin_unlock_irqrestore(&smu->lock, flags);
 210
 211         /* Call command completion handler if any */
 212         if (done)
 213                 done(cmd, misc);
 214
 215         /* It's an edge interrupt, nothing to do */
 216         return IRQ_HANDLED;
 217 }
 218
 219
 220 static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
 221 {
 222         /* I don't quite know what to do with this one, we seem to never
 223          * receive it, so I suspect we have to arm it someway in the SMU
 224          * to start getting events that way.
 225          */
 226
 227         printk(KERN_INFO "SMU: message interrupt !\n");
 228
 229         /* It's an edge interrupt, nothing to do */
 230         return IRQ_HANDLED;
 231 }
 232
 233
 234 /*
 235  * Queued command management.
 236  *
 237  */
 238
 239 int smu_queue_cmd(struct smu_cmd *cmd)
 240 {
 241         unsigned long flags;
 242
 243         if (smu == NULL)
 244                 return -ENODEV;
 245         if (cmd->data_len > SMU_MAX_DATA ||
 246             cmd->reply_len > SMU_MAX_DATA)
 247                 return -EINVAL;
 248
 249         cmd->status = 1;
 250         spin_lock_irqsave(&smu->lock, flags);
 251         list_add_tail(&cmd->link, &smu->cmd_list);
 252         if (smu->cmd_cur == NULL)
 253                 smu_start_cmd();
 254         spin_unlock_irqrestore(&smu->lock, flags);
 255
 256         return 0;
 257 }
 258 EXPORT_SYMBOL(smu_queue_cmd);
 259
 260
 261 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 262                      unsigned int data_len,
 263                      void (*done)(struct smu_cmd *cmd, void *misc),
 264                      void *misc, ...)
 265 {
 266         struct smu_cmd *cmd = &scmd->cmd;
 267         va_list list;
 268         int i;
 269
 270         if (data_len > sizeof(scmd->buffer))
 271                 return -EINVAL;
 272
 273         memset(scmd, 0, sizeof(*scmd));
 274         cmd->cmd = command;
 275         cmd->data_len = data_len;
 276         cmd->data_buf = scmd->buffer;
 277         cmd->reply_len = sizeof(scmd->buffer);
 278         cmd->reply_buf = scmd->buffer;
 279         cmd->done = done;
 280         cmd->misc = misc;
 281
 282         va_start(list, misc);
 283         for (i = 0; i < data_len; ++i)
 284                 scmd->buffer[i] = (u8)va_arg(list, int);
 285         va_end(list);
 286
 287         return smu_queue_cmd(cmd);
 288 }
 289 EXPORT_SYMBOL(smu_queue_simple);
 290
 291
 292 void smu_poll(void)
 293 {
 294         u8 gpio;
 295
 296         if (smu == NULL)
 297                 return;
 298
 299         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 300         if ((gpio & 7) == 7)
 301                 smu_db_intr(smu->db_irq, smu, NULL);
 302 }
 303 EXPORT_SYMBOL(smu_poll);
 304
 305
 306 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 307 {
 308         struct completion *comp = misc;
 309
 310         complete(comp);
 311 }
 312 EXPORT_SYMBOL(smu_done_complete);
 313
 314
 315 void smu_spinwait_cmd(struct smu_cmd *cmd)
 316 {
 317         while(cmd->status == 1)
 318                 smu_poll();
 319 }
 320 EXPORT_SYMBOL(smu_spinwait_cmd);
 321
 322
 323 /* RTC low level commands */
 324 static inline int bcd2hex (int n)
 325 {
 326         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 327 }
 328
 329
 330 static inline int hex2bcd (int n)
 331 {
 332         return ((n / 10) << 4) + (n % 10);
 333 }
 334
 335
 336 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 337                                         struct rtc_time *time)
 338 {
 339         cmd_buf->cmd = 0x8e;
 340         cmd_buf->length = 8;
 341         cmd_buf->data[0] = 0x80;
 342         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 343         cmd_buf->data[2] = hex2bcd(time->tm_min);
 344         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 345         cmd_buf->data[4] = time->tm_wday;
 346         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 347         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 348         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 349 }
 350
 351
 352 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 353 {
 354         struct smu_simple_cmd cmd;
 355         int rc;
 356
 357         if (smu == NULL)
 358                 return -ENODEV;
 359
 360         memset(time, 0, sizeof(struct rtc_time));
 361         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 362                               SMU_CMD_RTC_GET_DATETIME);
 363         if (rc)
 364                 return rc;
 365         smu_spinwait_simple(&cmd);
 366
 367         time->tm_sec = bcd2hex(cmd.buffer[0]);
 368         time->tm_min = bcd2hex(cmd.buffer[1]);
 369         time->tm_hour = bcd2hex(cmd.buffer[2]);
 370         time->tm_wday = bcd2hex(cmd.buffer[3]);
 371         time->tm_mday = bcd2hex(cmd.buffer[4]);
 372         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 373         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 374
 375         return 0;
 376 }
 377
 378
 379 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 380 {
 381         struct smu_simple_cmd cmd;
 382         int rc;
 383
 384         if (smu == NULL)
 385                 return -ENODEV;
 386
 387         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 388                               SMU_CMD_RTC_SET_DATETIME,
 389                               hex2bcd(time->tm_sec),
 390                               hex2bcd(time->tm_min),
 391                               hex2bcd(time->tm_hour),
 392                               time->tm_wday,
 393                               hex2bcd(time->tm_mday),
 394                               hex2bcd(time->tm_mon) + 1,
 395                               hex2bcd(time->tm_year - 100));
 396         if (rc)
 397                 return rc;
 398         smu_spinwait_simple(&cmd);
 399
 400         return 0;
 401 }
 402
 403
 404 void smu_shutdown(void)
 405 {
 406         struct smu_simple_cmd cmd;
 407
 408         if (smu == NULL)
 409                 return;
 410
 411         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 412                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 413                 return;
 414         smu_spinwait_simple(&cmd);
 415         for (;;)
 416                 ;
 417 }
 418
 419
 420 void smu_restart(void)
 421 {
 422         struct smu_simple_cmd cmd;
 423
 424         if (smu == NULL)
 425                 return;
 426
 427         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 428                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 429                 return;
 430         smu_spinwait_simple(&cmd);
 431         for (;;)
 432                 ;
 433 }
 434
 435
 436 int smu_present(void)
 437 {
 438         return smu != NULL;
 439 }
 440 EXPORT_SYMBOL(smu_present);
 441
 442
 443 int smu_init (void)
 444 {
 445         struct device_node *np;
 446         u32 *data;
 447
 448         np = of_find_node_by_type(NULL, "smu");
 449         if (np == NULL)
 450                 return -ENODEV;
 451
 452         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
 453
 454         if (smu_cmdbuf_abs == 0) {
 455                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 456                 return -EINVAL;
 457         }
 458
 459         smu = alloc_bootmem(sizeof(struct smu_device));
 460         if (smu == NULL)
 461                 return -ENOMEM;
 462         memset(smu, 0, sizeof(*smu));
 463
 464         spin_lock_init(&smu->lock);
 465         INIT_LIST_HEAD(&smu->cmd_list);
 466         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 467         smu->of_node = np;
 468         smu->db_irq = NO_IRQ;
 469         smu->msg_irq = NO_IRQ;
 470         init_timer(&smu->i2c_timer);
 471
 472         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 473          * 32 bits value safely
 474          */
 475         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 476         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 477
 478         np = of_find_node_by_name(NULL, "smu-doorbell");
 479         if (np == NULL) {
 480                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 481                 goto fail;
 482         }
 483         data = (u32 *)get_property(np, "reg", NULL);
 484         if (data == NULL) {
 485                 of_node_put(np);
 486                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 487                 goto fail;
 488         }
 489
 490         /* Current setup has one doorbell GPIO that does both doorbell
 491          * and ack. GPIOs are at 0x50, best would be to find that out
 492          * in the device-tree though.
 493          */
 494         smu->doorbell = *data;
 495         if (smu->doorbell < 0x50)
 496                 smu->doorbell += 0x50;
 497         if (np->n_intrs > 0)
 498                 smu->db_irq = np->intrs[0].line;
 499
 500         of_node_put(np);
 501
 502         /* Now look for the smu-interrupt GPIO */
 503         do {
 504                 np = of_find_node_by_name(NULL, "smu-interrupt");
 505                 if (np == NULL)
 506                         break;
 507                 data = (u32 *)get_property(np, "reg", NULL);
 508                 if (data == NULL) {
 509                         of_node_put(np);
 510                         break;
 511                 }
 512                 smu->msg = *data;
 513                 if (smu->msg < 0x50)
 514                         smu->msg += 0x50;
 515                 if (np->n_intrs > 0)
 516                         smu->msg_irq = np->intrs[0].line;
 517                 of_node_put(np);
 518         } while(0);
 519
 520         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 521          * device-tree entry giving the address. Best would probably to use
 522          * an offset for K2 base though, but let's do it that way for now.
 523          */
 524         smu->db_buf = ioremap(0x8000860c, 0x1000);
 525         if (smu->db_buf == NULL) {
 526                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 527                 goto fail;
 528         }
 529
 530         sys_ctrler = SYS_CTRLER_SMU;
 531         return 0;
 532
 533  fail:
 534         smu = NULL;
 535         return -ENXIO;
 536
 537 }
 538
 539
 540 static int smu_late_init(void)
 541 {
 542         if (!smu)
 543                 return 0;
 544
 545         /*
 546          * Try to request the interrupts
 547          */
 548
 549         if (smu->db_irq != NO_IRQ) {
 550                 if (request_irq(smu->db_irq, smu_db_intr,
 551                                 SA_SHIRQ, "SMU doorbell", smu) < 0) {
 552                         printk(KERN_WARNING "SMU: can't "
 553                                "request interrupt %d\n",
 554                                smu->db_irq);
 555                         smu->db_irq = NO_IRQ;
 556                 }
 557         }
 558
 559         if (smu->msg_irq != NO_IRQ) {
 560                 if (request_irq(smu->msg_irq, smu_msg_intr,
 561                                 SA_SHIRQ, "SMU message", smu) < 0) {
 562                         printk(KERN_WARNING "SMU: can't "
 563                                "request interrupt %d\n",
 564                                smu->msg_irq);
 565                         smu->msg_irq = NO_IRQ;
 566                 }
 567         }
 568
 569         return 0;
 570 }
 571 arch_initcall(smu_late_init);
 572
 573 /*
 574  * sysfs visibility
 575  */
 576
 577 static void smu_expose_childs(void *unused)
 578 {
 579         struct device_node *np;
 580
 581         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;) {
 582                 if (device_is_compatible(np, "smu-i2c")) {
 583                         char name[32];
 584                         u32 *reg = (u32 *)get_property(np, "reg", NULL);
 585
 586                         if (reg == NULL)
 587                                 continue;
 588                         sprintf(name, "smu-i2c-%02x", *reg);
 589                         of_platform_device_create(np, name, &smu->of_dev->dev);
 590                 }
 591         }
 592
 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         int rc;
 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         rc = 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 = (struct smu_i2c_cmd *)data;
 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 = 0x10;
 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                 smu->i2c_timer.function = smu_i2c_retry;
 747                 smu->i2c_timer.data = (unsigned long)cmd;
 748                 smu->i2c_timer.expires = jiffies + msecs_to_jiffies(5);
 749                 add_timer(&smu->i2c_timer);
 750                 return;
 751         }
 752
 753         /* If failure or stage 1, command is complete */
 754         if (fail || cmd->stage != 0) {
 755                 smu_i2c_complete_command(cmd, fail);
 756                 return;
 757         }
 758
 759         DPRINTK("SMU: going to stage 1\n");
 760
 761         /* Ok, initial command complete, now poll status */
 762         scmd->reply_buf = cmd->pdata;
 763         scmd->reply_len = 0x10;
 764         scmd->data_buf = cmd->pdata;
 765         scmd->data_len = 1;
 766         cmd->pdata[0] = 0;
 767         cmd->stage = 1;
 768         cmd->retries = 20;
 769         smu_queue_cmd(scmd);
 770 }
 771
 772
 773 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 774 {
 775         unsigned long flags;
 776
 777         if (smu == NULL)
 778                 return -ENODEV;
 779
 780         /* Fill most fields of scmd */
 781         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 782         cmd->scmd.done = smu_i2c_low_completion;
 783         cmd->scmd.misc = cmd;
 784         cmd->scmd.reply_buf = cmd->pdata;
 785         cmd->scmd.reply_len = 0x10;
 786         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 787         cmd->scmd.status = 1;
 788         cmd->stage = 0;
 789         cmd->pdata[0] = 0xff;
 790         cmd->retries = 20;
 791         cmd->status = 1;
 792
 793         /* Check transfer type, sanitize some "info" fields
 794          * based on transfer type and do more checking
 795          */
 796         cmd->info.caddr = cmd->info.devaddr;
 797         cmd->read = cmd->info.devaddr & 0x01;
 798         switch(cmd->info.type) {
 799         case SMU_I2C_TRANSFER_SIMPLE:
 800                 memset(&cmd->info.sublen, 0, 4);
 801                 break;
 802         case SMU_I2C_TRANSFER_COMBINED:
 803                 cmd->info.devaddr &= 0xfe;
 804         case SMU_I2C_TRANSFER_STDSUB:
 805                 if (cmd->info.sublen > 3)
 806                         return -EINVAL;
 807                 break;
 808         default:
 809                 return -EINVAL;
 810         }
 811
 812         /* Finish setting up command based on transfer direction
 813          */
 814         if (cmd->read) {
 815                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 816                         return -EINVAL;
 817                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 818                 cmd->scmd.data_len = 9;
 819         } else {
 820                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 821                         return -EINVAL;
 822                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 823         }
 824
 825         DPRINTK("SMU: i2c enqueuing command\n");
 826         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 827                 cmd->read ? "read" : "write", cmd->info.datalen,
 828                 cmd->info.bus, cmd->info.caddr,
 829                 cmd->info.subaddr[0], cmd->info.type);
 830
 831
 832         /* Enqueue command in i2c list, and if empty, enqueue also in
 833          * main command list
 834          */
 835         spin_lock_irqsave(&smu->lock, flags);
 836         if (smu->cmd_i2c_cur == NULL) {
 837                 smu->cmd_i2c_cur = cmd;
 838                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 839                 if (smu->cmd_cur == NULL)
 840                         smu_start_cmd();
 841         } else
 842                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 843         spin_unlock_irqrestore(&smu->lock, flags);
 844
 845         return 0;
 846 }
 847
 848
 849
 850 /*
 851  * Userland driver interface
 852  */
 853
 854
 855 static LIST_HEAD(smu_clist);
 856 static DEFINE_SPINLOCK(smu_clist_lock);
 857
 858 enum smu_file_mode {
 859         smu_file_commands,
 860         smu_file_events,
 861         smu_file_closing
 862 };
 863
 864 struct smu_private
 865 {
 866         struct list_head        list;
 867         enum smu_file_mode      mode;
 868         int                     busy;
 869         struct smu_cmd          cmd;
 870         spinlock_t              lock;
 871         wait_queue_head_t       wait;
 872         u8                      buffer[SMU_MAX_DATA];
 873 };
 874
 875
 876 static int smu_open(struct inode *inode, struct file *file)
 877 {
 878         struct smu_private *pp;
 879         unsigned long flags;
 880
 881         pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
 882         if (pp == 0)
 883                 return -ENOMEM;
 884         memset(pp, 0, sizeof(struct smu_private));
 885         spin_lock_init(&pp->lock);
 886         pp->mode = smu_file_commands;
 887         init_waitqueue_head(&pp->wait);
 888
 889         spin_lock_irqsave(&smu_clist_lock, flags);
 890         list_add(&pp->list, &smu_clist);
 891         spin_unlock_irqrestore(&smu_clist_lock, flags);
 892         file->private_data = pp;
 893
 894         return 0;
 895 }
 896
 897
 898 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
 899 {
 900         struct smu_private *pp = misc;
 901
 902         wake_up_all(&pp->wait);
 903 }
 904
 905
 906 static ssize_t smu_write(struct file *file, const char __user *buf,
 907                          size_t count, loff_t *ppos)
 908 {
 909         struct smu_private *pp = file->private_data;
 910         unsigned long flags;
 911         struct smu_user_cmd_hdr hdr;
 912         int rc = 0;
 913
 914         if (pp->busy)
 915                 return -EBUSY;
 916         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
 917                 return -EFAULT;
 918         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
 919                 pp->mode = smu_file_events;
 920                 return 0;
 921         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
 922                 return -EINVAL;
 923         else if (pp->mode != smu_file_commands)
 924                 return -EBADFD;
 925         else if (hdr.data_len > SMU_MAX_DATA)
 926                 return -EINVAL;
 927
 928         spin_lock_irqsave(&pp->lock, flags);
 929         if (pp->busy) {
 930                 spin_unlock_irqrestore(&pp->lock, flags);
 931                 return -EBUSY;
 932         }
 933         pp->busy = 1;
 934         pp->cmd.status = 1;
 935         spin_unlock_irqrestore(&pp->lock, flags);
 936
 937         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
 938                 pp->busy = 0;
 939                 return -EFAULT;
 940         }
 941
 942         pp->cmd.cmd = hdr.cmd;
 943         pp->cmd.data_len = hdr.data_len;
 944         pp->cmd.reply_len = SMU_MAX_DATA;
 945         pp->cmd.data_buf = pp->buffer;
 946         pp->cmd.reply_buf = pp->buffer;
 947         pp->cmd.done = smu_user_cmd_done;
 948         pp->cmd.misc = pp;
 949         rc = smu_queue_cmd(&pp->cmd);
 950         if (rc < 0)
 951                 return rc;
 952         return count;
 953 }
 954
 955
 956 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
 957                                 char __user *buf, size_t count)
 958 {
 959         DECLARE_WAITQUEUE(wait, current);
 960         struct smu_user_reply_hdr hdr;
 961         unsigned long flags;
 962         int size, rc = 0;
 963
 964         if (!pp->busy)
 965                 return 0;
 966         if (count < sizeof(struct smu_user_reply_hdr))
 967                 return -EOVERFLOW;
 968         spin_lock_irqsave(&pp->lock, flags);
 969         if (pp->cmd.status == 1) {
 970                 if (file->f_flags & O_NONBLOCK)
 971                         return -EAGAIN;
 972                 add_wait_queue(&pp->wait, &wait);
 973                 for (;;) {
 974                         set_current_state(TASK_INTERRUPTIBLE);
 975                         rc = 0;
 976                         if (pp->cmd.status != 1)
 977                                 break;
 978                         rc = -ERESTARTSYS;
 979                         if (signal_pending(current))
 980                                 break;
 981                         spin_unlock_irqrestore(&pp->lock, flags);
 982                         schedule();
 983                         spin_lock_irqsave(&pp->lock, flags);
 984                 }
 985                 set_current_state(TASK_RUNNING);
 986                 remove_wait_queue(&pp->wait, &wait);
 987         }
 988         spin_unlock_irqrestore(&pp->lock, flags);
 989         if (rc)
 990                 return rc;
 991         if (pp->cmd.status != 0)
 992                 pp->cmd.reply_len = 0;
 993         size = sizeof(hdr) + pp->cmd.reply_len;
 994         if (count < size)
 995                 size = count;
 996         rc = size;
 997         hdr.status = pp->cmd.status;
 998         hdr.reply_len = pp->cmd.reply_len;
 999         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1000                 return -EFAULT;
1001         size -= sizeof(hdr);
1002         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1003                 return -EFAULT;
1004         pp->busy = 0;
1005
1006         return rc;
1007 }
1008
1009
1010 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1011                                char __user *buf, size_t count)
1012 {
1013         /* Not implemented */
1014         msleep_interruptible(1000);
1015         return 0;
1016 }
1017
1018
1019 static ssize_t smu_read(struct file *file, char __user *buf,
1020                         size_t count, loff_t *ppos)
1021 {
1022         struct smu_private *pp = file->private_data;
1023
1024         if (pp->mode == smu_file_commands)
1025                 return smu_read_command(file, pp, buf, count);
1026         if (pp->mode == smu_file_events)
1027                 return smu_read_events(file, pp, buf, count);
1028
1029         return -EBADFD;
1030 }
1031
1032 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1033 {
1034         struct smu_private *pp = file->private_data;
1035         unsigned int mask = 0;
1036         unsigned long flags;
1037
1038         if (pp == 0)
1039                 return 0;
1040
1041         if (pp->mode == smu_file_commands) {
1042                 poll_wait(file, &pp->wait, wait);
1043
1044                 spin_lock_irqsave(&pp->lock, flags);
1045                 if (pp->busy && pp->cmd.status != 1)
1046                         mask |= POLLIN;
1047                 spin_unlock_irqrestore(&pp->lock, flags);
1048         } if (pp->mode == smu_file_events) {
1049                 /* Not yet implemented */
1050         }
1051         return mask;
1052 }
1053
1054 static int smu_release(struct inode *inode, struct file *file)
1055 {
1056         struct smu_private *pp = file->private_data;
1057         unsigned long flags;
1058         unsigned int busy;
1059
1060         if (pp == 0)
1061                 return 0;
1062
1063         file->private_data = NULL;
1064
1065         /* Mark file as closing to avoid races with new request */
1066         spin_lock_irqsave(&pp->lock, flags);
1067         pp->mode = smu_file_closing;
1068         busy = pp->busy;
1069
1070         /* Wait for any pending request to complete */
1071         if (busy && pp->cmd.status == 1) {
1072                 DECLARE_WAITQUEUE(wait, current);
1073
1074                 add_wait_queue(&pp->wait, &wait);
1075                 for (;;) {
1076                         set_current_state(TASK_UNINTERRUPTIBLE);
1077                         if (pp->cmd.status != 1)
1078                                 break;
1079                         spin_lock_irqsave(&pp->lock, flags);
1080                         schedule();
1081                         spin_unlock_irqrestore(&pp->lock, flags);
1082                 }
1083                 set_current_state(TASK_RUNNING);
1084                 remove_wait_queue(&pp->wait, &wait);
1085         }
1086         spin_unlock_irqrestore(&pp->lock, flags);
1087
1088         spin_lock_irqsave(&smu_clist_lock, flags);
1089         list_del(&pp->list);
1090         spin_unlock_irqrestore(&smu_clist_lock, flags);
1091         kfree(pp);
1092
1093         return 0;
1094 }
1095
1096
1097 static struct file_operations smu_device_fops = {
1098         .llseek         = no_llseek,
1099         .read           = smu_read,
1100         .write          = smu_write,
1101         .poll           = smu_fpoll,
1102         .open           = smu_open,
1103         .release        = smu_release,
1104 };
1105
1106 static struct miscdevice pmu_device = {
1107         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1108 };
1109
1110 static int smu_device_init(void)
1111 {
1112         if (!smu)
1113                 return -ENODEV;
1114         if (misc_register(&pmu_device) < 0)
1115                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1116         return 0;
1117 }
1118 device_initcall(smu_device_init);