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   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                 return IRQ_HANDLED;
 158
 159         cmd = smu->cmd_cur;
 160         smu->cmd_cur = NULL;
 161         if (cmd == NULL)
 162                 goto bail;
 163
 164         if (rc == 0) {
 165                 unsigned long faddr;
 166                 int reply_len;
 167                 u8 ack;
 168
 169                 /* CPU might have brought back the cache line, so we need
 170                  * to flush again before peeking at the SMU response. We
 171                  * flush the entire buffer for now as we haven't read the
 172                  * reply lenght (it's only 2 cache lines anyway)
 173                  */
 174                 faddr = (unsigned long)smu->cmd_buf;
 175                 flush_inval_dcache_range(faddr, faddr + 256);
 176
 177                 /* Now check ack */
 178                 ack = (~cmd->cmd) & 0xff;
 179                 if (ack != smu->cmd_buf->cmd) {
 180                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 181                                 ack, smu->cmd_buf->cmd);
 182                         rc = -EIO;
 183                 }
 184                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 185                 DPRINTK("SMU: reply len: %d\n", reply_len);
 186                 if (reply_len > cmd->reply_len) {
 187                         printk(KERN_WARNING "SMU: reply buffer too small,"
 188                                "got %d bytes for a %d bytes buffer\n",
 189                                reply_len, cmd->reply_len);
 190                         reply_len = cmd->reply_len;
 191                 }
 192                 cmd->reply_len = reply_len;
 193                 if (cmd->reply_buf && reply_len)
 194                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 195         }
 196
 197         /* Now complete the command. Write status last in order as we lost
 198          * ownership of the command structure as soon as it's no longer -1
 199          */
 200         done = cmd->done;
 201         misc = cmd->misc;
 202         mb();
 203         cmd->status = rc;
 204  bail:
 205         /* Start next command if any */
 206         smu_start_cmd();
 207         spin_unlock_irqrestore(&smu->lock, flags);
 208
 209         /* Call command completion handler if any */
 210         if (done)
 211                 done(cmd, misc);
 212
 213         /* It's an edge interrupt, nothing to do */
 214         return IRQ_HANDLED;
 215 }
 216
 217
 218 static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
 219 {
 220         /* I don't quite know what to do with this one, we seem to never
 221          * receive it, so I suspect we have to arm it someway in the SMU
 222          * to start getting events that way.
 223          */
 224
 225         printk(KERN_INFO "SMU: message interrupt !\n");
 226
 227         /* It's an edge interrupt, nothing to do */
 228         return IRQ_HANDLED;
 229 }
 230
 231
 232 /*
 233  * Queued command management.
 234  *
 235  */
 236
 237 int smu_queue_cmd(struct smu_cmd *cmd)
 238 {
 239         unsigned long flags;
 240
 241         if (smu == NULL)
 242                 return -ENODEV;
 243         if (cmd->data_len > SMU_MAX_DATA ||
 244             cmd->reply_len > SMU_MAX_DATA)
 245                 return -EINVAL;
 246
 247         cmd->status = 1;
 248         spin_lock_irqsave(&smu->lock, flags);
 249         list_add_tail(&cmd->link, &smu->cmd_list);
 250         if (smu->cmd_cur == NULL)
 251                 smu_start_cmd();
 252         spin_unlock_irqrestore(&smu->lock, flags);
 253
 254         return 0;
 255 }
 256 EXPORT_SYMBOL(smu_queue_cmd);
 257
 258
 259 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 260                      unsigned int data_len,
 261                      void (*done)(struct smu_cmd *cmd, void *misc),
 262                      void *misc, ...)
 263 {
 264         struct smu_cmd *cmd = &scmd->cmd;
 265         va_list list;
 266         int i;
 267
 268         if (data_len > sizeof(scmd->buffer))
 269                 return -EINVAL;
 270
 271         memset(scmd, 0, sizeof(*scmd));
 272         cmd->cmd = command;
 273         cmd->data_len = data_len;
 274         cmd->data_buf = scmd->buffer;
 275         cmd->reply_len = sizeof(scmd->buffer);
 276         cmd->reply_buf = scmd->buffer;
 277         cmd->done = done;
 278         cmd->misc = misc;
 279
 280         va_start(list, misc);
 281         for (i = 0; i < data_len; ++i)
 282                 scmd->buffer[i] = (u8)va_arg(list, int);
 283         va_end(list);
 284
 285         return smu_queue_cmd(cmd);
 286 }
 287 EXPORT_SYMBOL(smu_queue_simple);
 288
 289
 290 void smu_poll(void)
 291 {
 292         u8 gpio;
 293
 294         if (smu == NULL)
 295                 return;
 296
 297         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 298         if ((gpio & 7) == 7)
 299                 smu_db_intr(smu->db_irq, smu, NULL);
 300 }
 301 EXPORT_SYMBOL(smu_poll);
 302
 303
 304 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 305 {
 306         struct completion *comp = misc;
 307
 308         complete(comp);
 309 }
 310 EXPORT_SYMBOL(smu_done_complete);
 311
 312
 313 void smu_spinwait_cmd(struct smu_cmd *cmd)
 314 {
 315         while(cmd->status == 1)
 316                 smu_poll();
 317 }
 318 EXPORT_SYMBOL(smu_spinwait_cmd);
 319
 320
 321 /* RTC low level commands */
 322 static inline int bcd2hex (int n)
 323 {
 324         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 325 }
 326
 327
 328 static inline int hex2bcd (int n)
 329 {
 330         return ((n / 10) << 4) + (n % 10);
 331 }
 332
 333
 334 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 335                                         struct rtc_time *time)
 336 {
 337         cmd_buf->cmd = 0x8e;
 338         cmd_buf->length = 8;
 339         cmd_buf->data[0] = 0x80;
 340         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 341         cmd_buf->data[2] = hex2bcd(time->tm_min);
 342         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 343         cmd_buf->data[4] = time->tm_wday;
 344         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 345         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 346         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 347 }
 348
 349
 350 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 351 {
 352         struct smu_simple_cmd cmd;
 353         int rc;
 354
 355         if (smu == NULL)
 356                 return -ENODEV;
 357
 358         memset(time, 0, sizeof(struct rtc_time));
 359         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 360                               SMU_CMD_RTC_GET_DATETIME);
 361         if (rc)
 362                 return rc;
 363         smu_spinwait_simple(&cmd);
 364
 365         time->tm_sec = bcd2hex(cmd.buffer[0]);
 366         time->tm_min = bcd2hex(cmd.buffer[1]);
 367         time->tm_hour = bcd2hex(cmd.buffer[2]);
 368         time->tm_wday = bcd2hex(cmd.buffer[3]);
 369         time->tm_mday = bcd2hex(cmd.buffer[4]);
 370         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 371         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 372
 373         return 0;
 374 }
 375
 376
 377 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 378 {
 379         struct smu_simple_cmd cmd;
 380         int rc;
 381
 382         if (smu == NULL)
 383                 return -ENODEV;
 384
 385         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 386                               SMU_CMD_RTC_SET_DATETIME,
 387                               hex2bcd(time->tm_sec),
 388                               hex2bcd(time->tm_min),
 389                               hex2bcd(time->tm_hour),
 390                               time->tm_wday,
 391                               hex2bcd(time->tm_mday),
 392                               hex2bcd(time->tm_mon) + 1,
 393                               hex2bcd(time->tm_year - 100));
 394         if (rc)
 395                 return rc;
 396         smu_spinwait_simple(&cmd);
 397
 398         return 0;
 399 }
 400
 401
 402 void smu_shutdown(void)
 403 {
 404         struct smu_simple_cmd cmd;
 405
 406         if (smu == NULL)
 407                 return;
 408
 409         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 410                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 411                 return;
 412         smu_spinwait_simple(&cmd);
 413         for (;;)
 414                 ;
 415 }
 416
 417
 418 void smu_restart(void)
 419 {
 420         struct smu_simple_cmd cmd;
 421
 422         if (smu == NULL)
 423                 return;
 424
 425         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 426                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 427                 return;
 428         smu_spinwait_simple(&cmd);
 429         for (;;)
 430                 ;
 431 }
 432
 433
 434 int smu_present(void)
 435 {
 436         return smu != NULL;
 437 }
 438 EXPORT_SYMBOL(smu_present);
 439
 440
 441 int smu_init (void)
 442 {
 443         struct device_node *np;
 444         u32 *data;
 445
 446         np = of_find_node_by_type(NULL, "smu");
 447         if (np == NULL)
 448                 return -ENODEV;
 449
 450         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
 451
 452         if (smu_cmdbuf_abs == 0) {
 453                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 454                 return -EINVAL;
 455         }
 456
 457         smu = alloc_bootmem(sizeof(struct smu_device));
 458         if (smu == NULL)
 459                 return -ENOMEM;
 460         memset(smu, 0, sizeof(*smu));
 461
 462         spin_lock_init(&smu->lock);
 463         INIT_LIST_HEAD(&smu->cmd_list);
 464         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 465         smu->of_node = np;
 466         smu->db_irq = NO_IRQ;
 467         smu->msg_irq = NO_IRQ;
 468         init_timer(&smu->i2c_timer);
 469
 470         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 471          * 32 bits value safely
 472          */
 473         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 474         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 475
 476         np = of_find_node_by_name(NULL, "smu-doorbell");
 477         if (np == NULL) {
 478                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 479                 goto fail;
 480         }
 481         data = (u32 *)get_property(np, "reg", NULL);
 482         if (data == NULL) {
 483                 of_node_put(np);
 484                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 485                 goto fail;
 486         }
 487
 488         /* Current setup has one doorbell GPIO that does both doorbell
 489          * and ack. GPIOs are at 0x50, best would be to find that out
 490          * in the device-tree though.
 491          */
 492         smu->doorbell = *data;
 493         if (smu->doorbell < 0x50)
 494                 smu->doorbell += 0x50;
 495         if (np->n_intrs > 0)
 496                 smu->db_irq = np->intrs[0].line;
 497
 498         of_node_put(np);
 499
 500         /* Now look for the smu-interrupt GPIO */
 501         do {
 502                 np = of_find_node_by_name(NULL, "smu-interrupt");
 503                 if (np == NULL)
 504                         break;
 505                 data = (u32 *)get_property(np, "reg", NULL);
 506                 if (data == NULL) {
 507                         of_node_put(np);
 508                         break;
 509                 }
 510                 smu->msg = *data;
 511                 if (smu->msg < 0x50)
 512                         smu->msg += 0x50;
 513                 if (np->n_intrs > 0)
 514                         smu->msg_irq = np->intrs[0].line;
 515                 of_node_put(np);
 516         } while(0);
 517
 518         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 519          * device-tree entry giving the address. Best would probably to use
 520          * an offset for K2 base though, but let's do it that way for now.
 521          */
 522         smu->db_buf = ioremap(0x8000860c, 0x1000);
 523         if (smu->db_buf == NULL) {
 524                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 525                 goto fail;
 526         }
 527
 528         sys_ctrler = SYS_CTRLER_SMU;
 529         return 0;
 530
 531  fail:
 532         smu = NULL;
 533         return -ENXIO;
 534
 535 }
 536
 537
 538 static int smu_late_init(void)
 539 {
 540         if (!smu)
 541                 return 0;
 542
 543         /*
 544          * Try to request the interrupts
 545          */
 546
 547         if (smu->db_irq != NO_IRQ) {
 548                 if (request_irq(smu->db_irq, smu_db_intr,
 549                                 SA_SHIRQ, "SMU doorbell", smu) < 0) {
 550                         printk(KERN_WARNING "SMU: can't "
 551                                "request interrupt %d\n",
 552                                smu->db_irq);
 553                         smu->db_irq = NO_IRQ;
 554                 }
 555         }
 556
 557         if (smu->msg_irq != NO_IRQ) {
 558                 if (request_irq(smu->msg_irq, smu_msg_intr,
 559                                 SA_SHIRQ, "SMU message", smu) < 0) {
 560                         printk(KERN_WARNING "SMU: can't "
 561                                "request interrupt %d\n",
 562                                smu->msg_irq);
 563                         smu->msg_irq = NO_IRQ;
 564                 }
 565         }
 566
 567         return 0;
 568 }
 569 arch_initcall(smu_late_init);
 570
 571 /*
 572  * sysfs visibility
 573  */
 574
 575 static void smu_expose_childs(void *unused)
 576 {
 577         struct device_node *np;
 578
 579         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;) {
 580                 if (device_is_compatible(np, "smu-i2c")) {
 581                         char name[32];
 582                         u32 *reg = (u32 *)get_property(np, "reg", NULL);
 583
 584                         if (reg == NULL)
 585                                 continue;
 586                         sprintf(name, "smu-i2c-%02x", *reg);
 587                         of_platform_device_create(np, name, &smu->of_dev->dev);
 588                 }
 589         }
 590
 591 }
 592
 593 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
 594
 595 static int smu_platform_probe(struct of_device* dev,
 596                               const struct of_device_id *match)
 597 {
 598         if (!smu)
 599                 return -ENODEV;
 600         smu->of_dev = dev;
 601
 602         /*
 603          * Ok, we are matched, now expose all i2c busses. We have to defer
 604          * that unfortunately or it would deadlock inside the device model
 605          */
 606         schedule_work(&smu_expose_childs_work);
 607
 608         return 0;
 609 }
 610
 611 static struct of_device_id smu_platform_match[] =
 612 {
 613         {
 614                 .type           = "smu",
 615         },
 616         {},
 617 };
 618
 619 static struct of_platform_driver smu_of_platform_driver =
 620 {
 621         .name           = "smu",
 622         .match_table    = smu_platform_match,
 623         .probe          = smu_platform_probe,
 624 };
 625
 626 static int __init smu_init_sysfs(void)
 627 {
 628         int rc;
 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         rc = 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 = (struct smu_i2c_cmd *)data;
 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 = 0x10;
 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                 smu->i2c_timer.function = smu_i2c_retry;
 745                 smu->i2c_timer.data = (unsigned long)cmd;
 746                 smu->i2c_timer.expires = jiffies + msecs_to_jiffies(5);
 747                 add_timer(&smu->i2c_timer);
 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 = 0x10;
 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 = 0x10;
 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
 848 /*
 849  * Userland driver interface
 850  */
 851
 852
 853 static LIST_HEAD(smu_clist);
 854 static DEFINE_SPINLOCK(smu_clist_lock);
 855
 856 enum smu_file_mode {
 857         smu_file_commands,
 858         smu_file_events,
 859         smu_file_closing
 860 };
 861
 862 struct smu_private
 863 {
 864         struct list_head        list;
 865         enum smu_file_mode      mode;
 866         int                     busy;
 867         struct smu_cmd          cmd;
 868         spinlock_t              lock;
 869         wait_queue_head_t       wait;
 870         u8                      buffer[SMU_MAX_DATA];
 871 };
 872
 873
 874 static int smu_open(struct inode *inode, struct file *file)
 875 {
 876         struct smu_private *pp;
 877         unsigned long flags;
 878
 879         pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
 880         if (pp == 0)
 881                 return -ENOMEM;
 882         memset(pp, 0, sizeof(struct smu_private));
 883         spin_lock_init(&pp->lock);
 884         pp->mode = smu_file_commands;
 885         init_waitqueue_head(&pp->wait);
 886
 887         spin_lock_irqsave(&smu_clist_lock, flags);
 888         list_add(&pp->list, &smu_clist);
 889         spin_unlock_irqrestore(&smu_clist_lock, flags);
 890         file->private_data = pp;
 891
 892         return 0;
 893 }
 894
 895
 896 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
 897 {
 898         struct smu_private *pp = misc;
 899
 900         wake_up_all(&pp->wait);
 901 }
 902
 903
 904 static ssize_t smu_write(struct file *file, const char __user *buf,
 905                          size_t count, loff_t *ppos)
 906 {
 907         struct smu_private *pp = file->private_data;
 908         unsigned long flags;
 909         struct smu_user_cmd_hdr hdr;
 910         int rc = 0;
 911
 912         if (pp->busy)
 913                 return -EBUSY;
 914         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
 915                 return -EFAULT;
 916         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
 917                 pp->mode = smu_file_events;
 918                 return 0;
 919         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
 920                 return -EINVAL;
 921         else if (pp->mode != smu_file_commands)
 922                 return -EBADFD;
 923         else if (hdr.data_len > SMU_MAX_DATA)
 924                 return -EINVAL;
 925
 926         spin_lock_irqsave(&pp->lock, flags);
 927         if (pp->busy) {
 928                 spin_unlock_irqrestore(&pp->lock, flags);
 929                 return -EBUSY;
 930         }
 931         pp->busy = 1;
 932         pp->cmd.status = 1;
 933         spin_unlock_irqrestore(&pp->lock, flags);
 934
 935         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
 936                 pp->busy = 0;
 937                 return -EFAULT;
 938         }
 939
 940         pp->cmd.cmd = hdr.cmd;
 941         pp->cmd.data_len = hdr.data_len;
 942         pp->cmd.reply_len = SMU_MAX_DATA;
 943         pp->cmd.data_buf = pp->buffer;
 944         pp->cmd.reply_buf = pp->buffer;
 945         pp->cmd.done = smu_user_cmd_done;
 946         pp->cmd.misc = pp;
 947         rc = smu_queue_cmd(&pp->cmd);
 948         if (rc < 0)
 949                 return rc;
 950         return count;
 951 }
 952
 953
 954 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
 955                                 char __user *buf, size_t count)
 956 {
 957         DECLARE_WAITQUEUE(wait, current);
 958         struct smu_user_reply_hdr hdr;
 959         unsigned long flags;
 960         int size, rc = 0;
 961
 962         if (!pp->busy)
 963                 return 0;
 964         if (count < sizeof(struct smu_user_reply_hdr))
 965                 return -EOVERFLOW;
 966         spin_lock_irqsave(&pp->lock, flags);
 967         if (pp->cmd.status == 1) {
 968                 if (file->f_flags & O_NONBLOCK)
 969                         return -EAGAIN;
 970                 add_wait_queue(&pp->wait, &wait);
 971                 for (;;) {
 972                         set_current_state(TASK_INTERRUPTIBLE);
 973                         rc = 0;
 974                         if (pp->cmd.status != 1)
 975                                 break;
 976                         rc = -ERESTARTSYS;
 977                         if (signal_pending(current))
 978                                 break;
 979                         spin_unlock_irqrestore(&pp->lock, flags);
 980                         schedule();
 981                         spin_lock_irqsave(&pp->lock, flags);
 982                 }
 983                 set_current_state(TASK_RUNNING);
 984                 remove_wait_queue(&pp->wait, &wait);
 985         }
 986         spin_unlock_irqrestore(&pp->lock, flags);
 987         if (rc)
 988                 return rc;
 989         if (pp->cmd.status != 0)
 990                 pp->cmd.reply_len = 0;
 991         size = sizeof(hdr) + pp->cmd.reply_len;
 992         if (count < size)
 993                 size = count;
 994         rc = size;
 995         hdr.status = pp->cmd.status;
 996         hdr.reply_len = pp->cmd.reply_len;
 997         if (copy_to_user(buf, &hdr, sizeof(hdr)))
 998                 return -EFAULT;
 999         size -= sizeof(hdr);
1000         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1001                 return -EFAULT;
1002         pp->busy = 0;
1003
1004         return rc;
1005 }
1006
1007
1008 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1009                                char __user *buf, size_t count)
1010 {
1011         /* Not implemented */
1012         msleep_interruptible(1000);
1013         return 0;
1014 }
1015
1016
1017 static ssize_t smu_read(struct file *file, char __user *buf,
1018                         size_t count, loff_t *ppos)
1019 {
1020         struct smu_private *pp = file->private_data;
1021
1022         if (pp->mode == smu_file_commands)
1023                 return smu_read_command(file, pp, buf, count);
1024         if (pp->mode == smu_file_events)
1025                 return smu_read_events(file, pp, buf, count);
1026
1027         return -EBADFD;
1028 }
1029
1030 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1031 {
1032         struct smu_private *pp = file->private_data;
1033         unsigned int mask = 0;
1034         unsigned long flags;
1035
1036         if (pp == 0)
1037                 return 0;
1038
1039         if (pp->mode == smu_file_commands) {
1040                 poll_wait(file, &pp->wait, wait);
1041
1042                 spin_lock_irqsave(&pp->lock, flags);
1043                 if (pp->busy && pp->cmd.status != 1)
1044                         mask |= POLLIN;
1045                 spin_unlock_irqrestore(&pp->lock, flags);
1046         } if (pp->mode == smu_file_events) {
1047                 /* Not yet implemented */
1048         }
1049         return mask;
1050 }
1051
1052 static int smu_release(struct inode *inode, struct file *file)
1053 {
1054         struct smu_private *pp = file->private_data;
1055         unsigned long flags;
1056         unsigned int busy;
1057
1058         if (pp == 0)
1059                 return 0;
1060
1061         file->private_data = NULL;
1062
1063         /* Mark file as closing to avoid races with new request */
1064         spin_lock_irqsave(&pp->lock, flags);
1065         pp->mode = smu_file_closing;
1066         busy = pp->busy;
1067
1068         /* Wait for any pending request to complete */
1069         if (busy && pp->cmd.status == 1) {
1070                 DECLARE_WAITQUEUE(wait, current);
1071
1072                 add_wait_queue(&pp->wait, &wait);
1073                 for (;;) {
1074                         set_current_state(TASK_UNINTERRUPTIBLE);
1075                         if (pp->cmd.status != 1)
1076                                 break;
1077                         spin_lock_irqsave(&pp->lock, flags);
1078                         schedule();
1079                         spin_unlock_irqrestore(&pp->lock, flags);
1080                 }
1081                 set_current_state(TASK_RUNNING);
1082                 remove_wait_queue(&pp->wait, &wait);
1083         }
1084         spin_unlock_irqrestore(&pp->lock, flags);
1085
1086         spin_lock_irqsave(&smu_clist_lock, flags);
1087         list_del(&pp->list);
1088         spin_unlock_irqrestore(&smu_clist_lock, flags);
1089         kfree(pp);
1090
1091         return 0;
1092 }
1093
1094
1095 static struct file_operations smu_device_fops __pmacdata = {
1096         .llseek         = no_llseek,
1097         .read           = smu_read,
1098         .write          = smu_write,
1099         .poll           = smu_fpoll,
1100         .open           = smu_open,
1101         .release        = smu_release,
1102 };
1103
1104 static struct miscdevice pmu_device __pmacdata = {
1105         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1106 };
1107
1108 static int smu_device_init(void)
1109 {
1110         if (!smu)
1111                 return -ENODEV;
1112         if (misc_register(&pmu_device) < 0)
1113                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1114         return 0;
1115 }
1116 device_initcall(smu_device_init);