drivers/macintosh/smu.c

   1 /*
   2  * PowerMac G5 SMU driver
   3  *
   4  * Copyright 2004 J. Mayer <l_indien@magic.fr>
   5  * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   6  *
   7  * Released under the term of the GNU GPL v2.
   8  */
   9
  10 /*
  11  * TODO:
  12  *  - maybe add timeout to commands ?
  13  *  - blocking version of time functions
  14  *  - polling version of i2c commands (including timer that works with
  15  *    interrutps off)
  16  *  - maybe avoid some data copies with i2c by directly using the smu cmd
  17  *    buffer and a lower level internal interface
  18  *  - understand SMU -> CPU events and implement reception of them via
  19  *    the userland interface
  20  */
  21
  22 #include <linux/config.h>
  23 #include <linux/types.h>
  24 #include <linux/kernel.h>
  25 #include <linux/device.h>
  26 #include <linux/dmapool.h>
  27 #include <linux/bootmem.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/highmem.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/rtc.h>
  33 #include <linux/completion.h>
  34 #include <linux/miscdevice.h>
  35 #include <linux/delay.h>
  36 #include <linux/sysdev.h>
  37 #include <linux/poll.h>
  38
  39 #include <asm/byteorder.h>
  40 #include <asm/io.h>
  41 #include <asm/prom.h>
  42 #include <asm/machdep.h>
  43 #include <asm/pmac_feature.h>
  44 #include <asm/smu.h>
  45 #include <asm/sections.h>
  46 #include <asm/abs_addr.h>
  47 #include <asm/uaccess.h>
  48 #include <asm/of_device.h>
  49
  50 #define VERSION "0.7"
  51 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  52
  53 #undef DEBUG_SMU
  54
  55 #ifdef DEBUG_SMU
  56 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  57 #else
  58 #define DPRINTK(fmt, args...) do { } while (0)
  59 #endif
  60
  61 /*
  62  * This is the command buffer passed to the SMU hardware
  63  */
  64 #define SMU_MAX_DATA    254
  65
  66 struct smu_cmd_buf {
  67         u8 cmd;
  68         u8 length;
  69         u8 data[SMU_MAX_DATA];
  70 };
  71
  72 struct smu_device {
  73         spinlock_t              lock;
  74         struct device_node      *of_node;
  75         struct of_device        *of_dev;
  76         int                     doorbell;       /* doorbell gpio */
  77         u32 __iomem             *db_buf;        /* doorbell buffer */
  78         int                     db_irq;
  79         int                     msg;
  80         int                     msg_irq;
  81         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  82         u32                     cmd_buf_abs;    /* command buffer absolute */
  83         struct list_head        cmd_list;
  84         struct smu_cmd          *cmd_cur;       /* pending command */
  85         struct list_head        cmd_i2c_list;
  86         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  87         struct timer_list       i2c_timer;
  88 };
  89
  90 /*
  91  * I don't think there will ever be more than one SMU, so
  92  * for now, just hard code that
  93  */
  94 static struct smu_device        *smu;
  95 static DECLARE_MUTEX(smu_part_access);
  96
  97 static void smu_i2c_retry(unsigned long data);
  98
  99 /*
 100  * SMU driver low level stuff
 101  */
 102
 103 static void smu_start_cmd(void)
 104 {
 105         unsigned long faddr, fend;
 106         struct smu_cmd *cmd;
 107
 108         if (list_empty(&smu->cmd_list))
 109                 return;
 110
 111         /* Fetch first command in queue */
 112         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 113         smu->cmd_cur = cmd;
 114         list_del(&cmd->link);
 115
 116         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 117                 cmd->data_len);
 118         DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 119                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 120                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 121                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 122                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 123
 124         /* Fill the SMU command buffer */
 125         smu->cmd_buf->cmd = cmd->cmd;
 126         smu->cmd_buf->length = cmd->data_len;
 127         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 128
 129         /* Flush command and data to RAM */
 130         faddr = (unsigned long)smu->cmd_buf;
 131         fend = faddr + smu->cmd_buf->length + 2;
 132         flush_inval_dcache_range(faddr, fend);
 133
 134         /* This isn't exactly a DMA mapping here, I suspect
 135          * the SMU is actually communicating with us via i2c to the
 136          * northbridge or the CPU to access RAM.
 137          */
 138         writel(smu->cmd_buf_abs, smu->db_buf);
 139
 140         /* Ring the SMU doorbell */
 141         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 142 }
 143
 144
 145 static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs)
 146 {
 147         unsigned long flags;
 148         struct smu_cmd *cmd;
 149         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 150         void *misc = NULL;
 151         u8 gpio;
 152         int rc = 0;
 153
 154         /* SMU completed the command, well, we hope, let's make sure
 155          * of it
 156          */
 157         spin_lock_irqsave(&smu->lock, flags);
 158
 159         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 160         if ((gpio & 7) != 7) {
 161                 spin_unlock_irqrestore(&smu->lock, flags);
 162                 return IRQ_HANDLED;
 163         }
 164
 165         cmd = smu->cmd_cur;
 166         smu->cmd_cur = NULL;
 167         if (cmd == NULL)
 168                 goto bail;
 169
 170         if (rc == 0) {
 171                 unsigned long faddr;
 172                 int reply_len;
 173                 u8 ack;
 174
 175                 /* CPU might have brought back the cache line, so we need
 176                  * to flush again before peeking at the SMU response. We
 177                  * flush the entire buffer for now as we haven't read the
 178                  * reply lenght (it's only 2 cache lines anyway)
 179                  */
 180                 faddr = (unsigned long)smu->cmd_buf;
 181                 flush_inval_dcache_range(faddr, faddr + 256);
 182
 183                 /* Now check ack */
 184                 ack = (~cmd->cmd) & 0xff;
 185                 if (ack != smu->cmd_buf->cmd) {
 186                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 187                                 ack, smu->cmd_buf->cmd);
 188                         rc = -EIO;
 189                 }
 190                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 191                 DPRINTK("SMU: reply len: %d\n", reply_len);
 192                 if (reply_len > cmd->reply_len) {
 193                         printk(KERN_WARNING "SMU: reply buffer too small,"
 194                                "got %d bytes for a %d bytes buffer\n",
 195                                reply_len, cmd->reply_len);
 196                         reply_len = cmd->reply_len;
 197                 }
 198                 cmd->reply_len = reply_len;
 199                 if (cmd->reply_buf && reply_len)
 200                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 201         }
 202
 203         /* Now complete the command. Write status last in order as we lost
 204          * ownership of the command structure as soon as it's no longer -1
 205          */
 206         done = cmd->done;
 207         misc = cmd->misc;
 208         mb();
 209         cmd->status = rc;
 210  bail:
 211         /* Start next command if any */
 212         smu_start_cmd();
 213         spin_unlock_irqrestore(&smu->lock, flags);
 214
 215         /* Call command completion handler if any */
 216         if (done)
 217                 done(cmd, misc);
 218
 219         /* It's an edge interrupt, nothing to do */
 220         return IRQ_HANDLED;
 221 }
 222
 223
 224 static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
 225 {
 226         /* I don't quite know what to do with this one, we seem to never
 227          * receive it, so I suspect we have to arm it someway in the SMU
 228          * to start getting events that way.
 229          */
 230
 231         printk(KERN_INFO "SMU: message interrupt !\n");
 232
 233         /* It's an edge interrupt, nothing to do */
 234         return IRQ_HANDLED;
 235 }
 236
 237
 238 /*
 239  * Queued command management.
 240  *
 241  */
 242
 243 int smu_queue_cmd(struct smu_cmd *cmd)
 244 {
 245         unsigned long flags;
 246
 247         if (smu == NULL)
 248                 return -ENODEV;
 249         if (cmd->data_len > SMU_MAX_DATA ||
 250             cmd->reply_len > SMU_MAX_DATA)
 251                 return -EINVAL;
 252
 253         cmd->status = 1;
 254         spin_lock_irqsave(&smu->lock, flags);
 255         list_add_tail(&cmd->link, &smu->cmd_list);
 256         if (smu->cmd_cur == NULL)
 257                 smu_start_cmd();
 258         spin_unlock_irqrestore(&smu->lock, flags);
 259
 260         return 0;
 261 }
 262 EXPORT_SYMBOL(smu_queue_cmd);
 263
 264
 265 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 266                      unsigned int data_len,
 267                      void (*done)(struct smu_cmd *cmd, void *misc),
 268                      void *misc, ...)
 269 {
 270         struct smu_cmd *cmd = &scmd->cmd;
 271         va_list list;
 272         int i;
 273
 274         if (data_len > sizeof(scmd->buffer))
 275                 return -EINVAL;
 276
 277         memset(scmd, 0, sizeof(*scmd));
 278         cmd->cmd = command;
 279         cmd->data_len = data_len;
 280         cmd->data_buf = scmd->buffer;
 281         cmd->reply_len = sizeof(scmd->buffer);
 282         cmd->reply_buf = scmd->buffer;
 283         cmd->done = done;
 284         cmd->misc = misc;
 285
 286         va_start(list, misc);
 287         for (i = 0; i < data_len; ++i)
 288                 scmd->buffer[i] = (u8)va_arg(list, int);
 289         va_end(list);
 290
 291         return smu_queue_cmd(cmd);
 292 }
 293 EXPORT_SYMBOL(smu_queue_simple);
 294
 295
 296 void smu_poll(void)
 297 {
 298         u8 gpio;
 299
 300         if (smu == NULL)
 301                 return;
 302
 303         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 304         if ((gpio & 7) == 7)
 305                 smu_db_intr(smu->db_irq, smu, NULL);
 306 }
 307 EXPORT_SYMBOL(smu_poll);
 308
 309
 310 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 311 {
 312         struct completion *comp = misc;
 313
 314         complete(comp);
 315 }
 316 EXPORT_SYMBOL(smu_done_complete);
 317
 318
 319 void smu_spinwait_cmd(struct smu_cmd *cmd)
 320 {
 321         while(cmd->status == 1)
 322                 smu_poll();
 323 }
 324 EXPORT_SYMBOL(smu_spinwait_cmd);
 325
 326
 327 /* RTC low level commands */
 328 static inline int bcd2hex (int n)
 329 {
 330         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 331 }
 332
 333
 334 static inline int hex2bcd (int n)
 335 {
 336         return ((n / 10) << 4) + (n % 10);
 337 }
 338
 339
 340 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 341                                         struct rtc_time *time)
 342 {
 343         cmd_buf->cmd = 0x8e;
 344         cmd_buf->length = 8;
 345         cmd_buf->data[0] = 0x80;
 346         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 347         cmd_buf->data[2] = hex2bcd(time->tm_min);
 348         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 349         cmd_buf->data[4] = time->tm_wday;
 350         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 351         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 352         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 353 }
 354
 355
 356 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 357 {
 358         struct smu_simple_cmd cmd;
 359         int rc;
 360
 361         if (smu == NULL)
 362                 return -ENODEV;
 363
 364         memset(time, 0, sizeof(struct rtc_time));
 365         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 366                               SMU_CMD_RTC_GET_DATETIME);
 367         if (rc)
 368                 return rc;
 369         smu_spinwait_simple(&cmd);
 370
 371         time->tm_sec = bcd2hex(cmd.buffer[0]);
 372         time->tm_min = bcd2hex(cmd.buffer[1]);
 373         time->tm_hour = bcd2hex(cmd.buffer[2]);
 374         time->tm_wday = bcd2hex(cmd.buffer[3]);
 375         time->tm_mday = bcd2hex(cmd.buffer[4]);
 376         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 377         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 378
 379         return 0;
 380 }
 381
 382
 383 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 384 {
 385         struct smu_simple_cmd cmd;
 386         int rc;
 387
 388         if (smu == NULL)
 389                 return -ENODEV;
 390
 391         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 392                               SMU_CMD_RTC_SET_DATETIME,
 393                               hex2bcd(time->tm_sec),
 394                               hex2bcd(time->tm_min),
 395                               hex2bcd(time->tm_hour),
 396                               time->tm_wday,
 397                               hex2bcd(time->tm_mday),
 398                               hex2bcd(time->tm_mon) + 1,
 399                               hex2bcd(time->tm_year - 100));
 400         if (rc)
 401                 return rc;
 402         smu_spinwait_simple(&cmd);
 403
 404         return 0;
 405 }
 406
 407
 408 void smu_shutdown(void)
 409 {
 410         struct smu_simple_cmd cmd;
 411
 412         if (smu == NULL)
 413                 return;
 414
 415         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 416                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 417                 return;
 418         smu_spinwait_simple(&cmd);
 419         for (;;)
 420                 ;
 421 }
 422
 423
 424 void smu_restart(void)
 425 {
 426         struct smu_simple_cmd cmd;
 427
 428         if (smu == NULL)
 429                 return;
 430
 431         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 432                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 433                 return;
 434         smu_spinwait_simple(&cmd);
 435         for (;;)
 436                 ;
 437 }
 438
 439
 440 int smu_present(void)
 441 {
 442         return smu != NULL;
 443 }
 444 EXPORT_SYMBOL(smu_present);
 445
 446
 447 int __init smu_init (void)
 448 {
 449         struct device_node *np;
 450         u32 *data;
 451
 452         np = of_find_node_by_type(NULL, "smu");
 453         if (np == NULL)
 454                 return -ENODEV;
 455
 456         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
 457
 458         if (smu_cmdbuf_abs == 0) {
 459                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 460                 return -EINVAL;
 461         }
 462
 463         smu = alloc_bootmem(sizeof(struct smu_device));
 464         if (smu == NULL)
 465                 return -ENOMEM;
 466         memset(smu, 0, sizeof(*smu));
 467
 468         spin_lock_init(&smu->lock);
 469         INIT_LIST_HEAD(&smu->cmd_list);
 470         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 471         smu->of_node = np;
 472         smu->db_irq = NO_IRQ;
 473         smu->msg_irq = NO_IRQ;
 474
 475         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 476          * 32 bits value safely
 477          */
 478         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 479         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 480
 481         np = of_find_node_by_name(NULL, "smu-doorbell");
 482         if (np == NULL) {
 483                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 484                 goto fail;
 485         }
 486         data = (u32 *)get_property(np, "reg", NULL);
 487         if (data == NULL) {
 488                 of_node_put(np);
 489                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 490                 goto fail;
 491         }
 492
 493         /* Current setup has one doorbell GPIO that does both doorbell
 494          * and ack. GPIOs are at 0x50, best would be to find that out
 495          * in the device-tree though.
 496          */
 497         smu->doorbell = *data;
 498         if (smu->doorbell < 0x50)
 499                 smu->doorbell += 0x50;
 500         if (np->n_intrs > 0)
 501                 smu->db_irq = np->intrs[0].line;
 502
 503         of_node_put(np);
 504
 505         /* Now look for the smu-interrupt GPIO */
 506         do {
 507                 np = of_find_node_by_name(NULL, "smu-interrupt");
 508                 if (np == NULL)
 509                         break;
 510                 data = (u32 *)get_property(np, "reg", NULL);
 511                 if (data == NULL) {
 512                         of_node_put(np);
 513                         break;
 514                 }
 515                 smu->msg = *data;
 516                 if (smu->msg < 0x50)
 517                         smu->msg += 0x50;
 518                 if (np->n_intrs > 0)
 519                         smu->msg_irq = np->intrs[0].line;
 520                 of_node_put(np);
 521         } while(0);
 522
 523         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 524          * device-tree entry giving the address. Best would probably to use
 525          * an offset for K2 base though, but let's do it that way for now.
 526          */
 527         smu->db_buf = ioremap(0x8000860c, 0x1000);
 528         if (smu->db_buf == NULL) {
 529                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 530                 goto fail;
 531         }
 532
 533         sys_ctrler = SYS_CTRLER_SMU;
 534         return 0;
 535
 536  fail:
 537         smu = NULL;
 538         return -ENXIO;
 539
 540 }
 541
 542
 543 static int smu_late_init(void)
 544 {
 545         if (!smu)
 546                 return 0;
 547
 548         init_timer(&smu->i2c_timer);
 549         smu->i2c_timer.function = smu_i2c_retry;
 550         smu->i2c_timer.data = (unsigned long)smu;
 551
 552         /*
 553          * Try to request the interrupts
 554          */
 555
 556         if (smu->db_irq != NO_IRQ) {
 557                 if (request_irq(smu->db_irq, smu_db_intr,
 558                                 SA_SHIRQ, "SMU doorbell", smu) < 0) {
 559                         printk(KERN_WARNING "SMU: can't "
 560                                "request interrupt %d\n",
 561                                smu->db_irq);
 562                         smu->db_irq = NO_IRQ;
 563                 }
 564         }
 565
 566         if (smu->msg_irq != NO_IRQ) {
 567                 if (request_irq(smu->msg_irq, smu_msg_intr,
 568                                 SA_SHIRQ, "SMU message", smu) < 0) {
 569                         printk(KERN_WARNING "SMU: can't "
 570                                "request interrupt %d\n",
 571                                smu->msg_irq);
 572                         smu->msg_irq = NO_IRQ;
 573                 }
 574         }
 575
 576         return 0;
 577 }
 578 /* This has to be before arch_initcall as the low i2c stuff relies on the
 579  * above having been done before we reach arch_initcalls
 580  */
 581 core_initcall(smu_late_init);
 582
 583 /*
 584  * sysfs visibility
 585  */
 586
 587 static void smu_create_i2c(struct device_node *np)
 588 {
 589         char name[32];
 590         u32 *reg = (u32 *)get_property(np, "reg", NULL);
 591
 592         if (reg != NULL) {
 593                 sprintf(name, "smu-i2c-%02x", *reg);
 594                 of_platform_device_create(np, name, &smu->of_dev->dev);
 595         }
 596 }
 597
 598 static void smu_expose_childs(void *unused)
 599 {
 600         struct device_node *np, *gp;
 601
 602         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;) {
 603                 if (device_is_compatible(np, "smu-i2c-control")) {
 604                         gp = NULL;
 605                         while ((gp = of_get_next_child(np, gp)) != NULL)
 606                                 if (device_is_compatible(gp, "i2c-bus"))
 607                                         smu_create_i2c(gp);
 608                 } else if (device_is_compatible(np, "smu-i2c"))
 609                         smu_create_i2c(np);
 610                 if (device_is_compatible(np, "smu-sensors"))
 611                         of_platform_device_create(np, "smu-sensors",
 612                                                   &smu->of_dev->dev);
 613         }
 614
 615 }
 616
 617 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
 618
 619 static int smu_platform_probe(struct of_device* dev,
 620                               const struct of_device_id *match)
 621 {
 622         if (!smu)
 623                 return -ENODEV;
 624         smu->of_dev = dev;
 625
 626         /*
 627          * Ok, we are matched, now expose all i2c busses. We have to defer
 628          * that unfortunately or it would deadlock inside the device model
 629          */
 630         schedule_work(&smu_expose_childs_work);
 631
 632         return 0;
 633 }
 634
 635 static struct of_device_id smu_platform_match[] =
 636 {
 637         {
 638                 .type           = "smu",
 639         },
 640         {},
 641 };
 642
 643 static struct of_platform_driver smu_of_platform_driver =
 644 {
 645         .name           = "smu",
 646         .match_table    = smu_platform_match,
 647         .probe          = smu_platform_probe,
 648 };
 649
 650 static int __init smu_init_sysfs(void)
 651 {
 652         int rc;
 653
 654         /*
 655          * Due to sysfs bogosity, a sysdev is not a real device, so
 656          * we should in fact create both if we want sysdev semantics
 657          * for power management.
 658          * For now, we don't power manage machines with an SMU chip,
 659          * I'm a bit too far from figuring out how that works with those
 660          * new chipsets, but that will come back and bite us
 661          */
 662         rc = of_register_driver(&smu_of_platform_driver);
 663         return 0;
 664 }
 665
 666 device_initcall(smu_init_sysfs);
 667
 668 struct of_device *smu_get_ofdev(void)
 669 {
 670         if (!smu)
 671                 return NULL;
 672         return smu->of_dev;
 673 }
 674
 675 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 676
 677 /*
 678  * i2c interface
 679  */
 680
 681 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 682 {
 683         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 684         void *misc = cmd->misc;
 685         unsigned long flags;
 686
 687         /* Check for read case */
 688         if (!fail && cmd->read) {
 689                 if (cmd->pdata[0] < 1)
 690                         fail = 1;
 691                 else
 692                         memcpy(cmd->info.data, &cmd->pdata[1],
 693                                cmd->info.datalen);
 694         }
 695
 696         DPRINTK("SMU: completing, success: %d\n", !fail);
 697
 698         /* Update status and mark no pending i2c command with lock
 699          * held so nobody comes in while we dequeue an eventual
 700          * pending next i2c command
 701          */
 702         spin_lock_irqsave(&smu->lock, flags);
 703         smu->cmd_i2c_cur = NULL;
 704         wmb();
 705         cmd->status = fail ? -EIO : 0;
 706
 707         /* Is there another i2c command waiting ? */
 708         if (!list_empty(&smu->cmd_i2c_list)) {
 709                 struct smu_i2c_cmd *newcmd;
 710
 711                 /* Fetch it, new current, remove from list */
 712                 newcmd = list_entry(smu->cmd_i2c_list.next,
 713                                     struct smu_i2c_cmd, link);
 714                 smu->cmd_i2c_cur = newcmd;
 715                 list_del(&cmd->link);
 716
 717                 /* Queue with low level smu */
 718                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 719                 if (smu->cmd_cur == NULL)
 720                         smu_start_cmd();
 721         }
 722         spin_unlock_irqrestore(&smu->lock, flags);
 723
 724         /* Call command completion handler if any */
 725         if (done)
 726                 done(cmd, misc);
 727
 728 }
 729
 730
 731 static void smu_i2c_retry(unsigned long data)
 732 {
 733         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 734
 735         DPRINTK("SMU: i2c failure, requeuing...\n");
 736
 737         /* requeue command simply by resetting reply_len */
 738         cmd->pdata[0] = 0xff;
 739         cmd->scmd.reply_len = sizeof(cmd->pdata);
 740         smu_queue_cmd(&cmd->scmd);
 741 }
 742
 743
 744 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 745 {
 746         struct smu_i2c_cmd      *cmd = misc;
 747         int                     fail = 0;
 748
 749         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 750                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 751
 752         /* Check for possible status */
 753         if (scmd->status < 0)
 754                 fail = 1;
 755         else if (cmd->read) {
 756                 if (cmd->stage == 0)
 757                         fail = cmd->pdata[0] != 0;
 758                 else
 759                         fail = cmd->pdata[0] >= 0x80;
 760         } else {
 761                 fail = cmd->pdata[0] != 0;
 762         }
 763
 764         /* Handle failures by requeuing command, after 5ms interval
 765          */
 766         if (fail && --cmd->retries > 0) {
 767                 DPRINTK("SMU: i2c failure, starting timer...\n");
 768                 BUG_ON(cmd != smu->cmd_i2c_cur);
 769                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 770                 return;
 771         }
 772
 773         /* If failure or stage 1, command is complete */
 774         if (fail || cmd->stage != 0) {
 775                 smu_i2c_complete_command(cmd, fail);
 776                 return;
 777         }
 778
 779         DPRINTK("SMU: going to stage 1\n");
 780
 781         /* Ok, initial command complete, now poll status */
 782         scmd->reply_buf = cmd->pdata;
 783         scmd->reply_len = sizeof(cmd->pdata);
 784         scmd->data_buf = cmd->pdata;
 785         scmd->data_len = 1;
 786         cmd->pdata[0] = 0;
 787         cmd->stage = 1;
 788         cmd->retries = 20;
 789         smu_queue_cmd(scmd);
 790 }
 791
 792
 793 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 794 {
 795         unsigned long flags;
 796
 797         if (smu == NULL)
 798                 return -ENODEV;
 799
 800         /* Fill most fields of scmd */
 801         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 802         cmd->scmd.done = smu_i2c_low_completion;
 803         cmd->scmd.misc = cmd;
 804         cmd->scmd.reply_buf = cmd->pdata;
 805         cmd->scmd.reply_len = sizeof(cmd->pdata);
 806         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 807         cmd->scmd.status = 1;
 808         cmd->stage = 0;
 809         cmd->pdata[0] = 0xff;
 810         cmd->retries = 20;
 811         cmd->status = 1;
 812
 813         /* Check transfer type, sanitize some "info" fields
 814          * based on transfer type and do more checking
 815          */
 816         cmd->info.caddr = cmd->info.devaddr;
 817         cmd->read = cmd->info.devaddr & 0x01;
 818         switch(cmd->info.type) {
 819         case SMU_I2C_TRANSFER_SIMPLE:
 820                 memset(&cmd->info.sublen, 0, 4);
 821                 break;
 822         case SMU_I2C_TRANSFER_COMBINED:
 823                 cmd->info.devaddr &= 0xfe;
 824         case SMU_I2C_TRANSFER_STDSUB:
 825                 if (cmd->info.sublen > 3)
 826                         return -EINVAL;
 827                 break;
 828         default:
 829                 return -EINVAL;
 830         }
 831
 832         /* Finish setting up command based on transfer direction
 833          */
 834         if (cmd->read) {
 835                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 836                         return -EINVAL;
 837                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 838                 cmd->scmd.data_len = 9;
 839         } else {
 840                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 841                         return -EINVAL;
 842                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 843         }
 844
 845         DPRINTK("SMU: i2c enqueuing command\n");
 846         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 847                 cmd->read ? "read" : "write", cmd->info.datalen,
 848                 cmd->info.bus, cmd->info.caddr,
 849                 cmd->info.subaddr[0], cmd->info.type);
 850
 851
 852         /* Enqueue command in i2c list, and if empty, enqueue also in
 853          * main command list
 854          */
 855         spin_lock_irqsave(&smu->lock, flags);
 856         if (smu->cmd_i2c_cur == NULL) {
 857                 smu->cmd_i2c_cur = cmd;
 858                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 859                 if (smu->cmd_cur == NULL)
 860                         smu_start_cmd();
 861         } else
 862                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 863         spin_unlock_irqrestore(&smu->lock, flags);
 864
 865         return 0;
 866 }
 867
 868 /*
 869  * Handling of "partitions"
 870  */
 871
 872 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 873 {
 874         DECLARE_COMPLETION(comp);
 875         unsigned int chunk;
 876         struct smu_cmd cmd;
 877         int rc;
 878         u8 params[8];
 879
 880         /* We currently use a chunk size of 0xe. We could check the
 881          * SMU firmware version and use bigger sizes though
 882          */
 883         chunk = 0xe;
 884
 885         while (len) {
 886                 unsigned int clen = min(len, chunk);
 887
 888                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 889                 cmd.data_len = 7;
 890                 cmd.data_buf = params;
 891                 cmd.reply_len = chunk;
 892                 cmd.reply_buf = dest;
 893                 cmd.done = smu_done_complete;
 894                 cmd.misc = &comp;
 895                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 896                 params[1] = 0x4;
 897                 *((u32 *)&params[2]) = addr;
 898                 params[6] = clen;
 899
 900                 rc = smu_queue_cmd(&cmd);
 901                 if (rc)
 902                         return rc;
 903                 wait_for_completion(&comp);
 904                 if (cmd.status != 0)
 905                         return rc;
 906                 if (cmd.reply_len != clen) {
 907                         printk(KERN_DEBUG "SMU: short read in "
 908                                "smu_read_datablock, got: %d, want: %d\n",
 909                                cmd.reply_len, clen);
 910                         return -EIO;
 911                 }
 912                 len -= clen;
 913                 addr += clen;
 914                 dest += clen;
 915         }
 916         return 0;
 917 }
 918
 919 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 920 {
 921         DECLARE_COMPLETION(comp);
 922         struct smu_simple_cmd cmd;
 923         unsigned int addr, len, tlen;
 924         struct smu_sdbp_header *hdr;
 925         struct property *prop;
 926
 927         /* First query the partition info */
 928         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 929         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 930                          smu_done_complete, &comp,
 931                          SMU_CMD_PARTITION_LATEST, id);
 932         wait_for_completion(&comp);
 933         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 934                 cmd.cmd.status, cmd.cmd.reply_len);
 935
 936         /* Partition doesn't exist (or other error) */
 937         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 938                 return NULL;
 939
 940         /* Fetch address and length from reply */
 941         addr = *((u16 *)cmd.buffer);
 942         len = cmd.buffer[3] << 2;
 943         /* Calucluate total length to allocate, including the 17 bytes
 944          * for "sdb-partition-XX" that we append at the end of the buffer
 945          */
 946         tlen = sizeof(struct property) + len + 18;
 947
 948         prop = kcalloc(tlen, 1, GFP_KERNEL);
 949         if (prop == NULL)
 950                 return NULL;
 951         hdr = (struct smu_sdbp_header *)(prop + 1);
 952         prop->name = ((char *)prop) + tlen - 18;
 953         sprintf(prop->name, "sdb-partition-%02x", id);
 954         prop->length = len;
 955         prop->value = (unsigned char *)hdr;
 956         prop->next = NULL;
 957
 958         /* Read the datablock */
 959         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 960                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 961                        "partition %02x !\n", id);
 962                 goto failure;
 963         }
 964
 965         /* Got it, check a few things and create the property */
 966         if (hdr->id != id) {
 967                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 968                        "%02x !\n", id, hdr->id);
 969                 goto failure;
 970         }
 971         if (prom_add_property(smu->of_node, prop)) {
 972                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 973                        "property !\n", id);
 974                 goto failure;
 975         }
 976
 977         return hdr;
 978  failure:
 979         kfree(prop);
 980         return NULL;
 981 }
 982
 983 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
 984  * when interruptible is 1
 985  */
 986 struct smu_sdbp_header *__smu_get_sdb_partition(int id, unsigned int *size,
 987                                                 int interruptible)
 988 {
 989         char pname[32];
 990         struct smu_sdbp_header *part;
 991
 992         if (!smu)
 993                 return NULL;
 994
 995         sprintf(pname, "sdb-partition-%02x", id);
 996
 997         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
 998
 999         if (interruptible) {
1000                 int rc;
1001                 rc = down_interruptible(&smu_part_access);
1002                 if (rc)
1003                         return ERR_PTR(rc);
1004         } else
1005                 down(&smu_part_access);
1006
1007         part = (struct smu_sdbp_header *)get_property(smu->of_node,
1008                                                       pname, size);
1009         if (part == NULL) {
1010                 DPRINTK("trying to extract from SMU ...\n");
1011                 part = smu_create_sdb_partition(id);
1012                 if (part != NULL && size)
1013                         *size = part->len << 2;
1014         }
1015         up(&smu_part_access);
1016         return part;
1017 }
1018
1019 struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1020 {
1021         return __smu_get_sdb_partition(id, size, 0);
1022 }
1023 EXPORT_SYMBOL(smu_get_sdb_partition);
1024
1025
1026 /*
1027  * Userland driver interface
1028  */
1029
1030
1031 static LIST_HEAD(smu_clist);
1032 static DEFINE_SPINLOCK(smu_clist_lock);
1033
1034 enum smu_file_mode {
1035         smu_file_commands,
1036         smu_file_events,
1037         smu_file_closing
1038 };
1039
1040 struct smu_private
1041 {
1042         struct list_head        list;
1043         enum smu_file_mode      mode;
1044         int                     busy;
1045         struct smu_cmd          cmd;
1046         spinlock_t              lock;
1047         wait_queue_head_t       wait;
1048         u8                      buffer[SMU_MAX_DATA];
1049 };
1050
1051
1052 static int smu_open(struct inode *inode, struct file *file)
1053 {
1054         struct smu_private *pp;
1055         unsigned long flags;
1056
1057         pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
1058         if (pp == 0)
1059                 return -ENOMEM;
1060         memset(pp, 0, sizeof(struct smu_private));
1061         spin_lock_init(&pp->lock);
1062         pp->mode = smu_file_commands;
1063         init_waitqueue_head(&pp->wait);
1064
1065         spin_lock_irqsave(&smu_clist_lock, flags);
1066         list_add(&pp->list, &smu_clist);
1067         spin_unlock_irqrestore(&smu_clist_lock, flags);
1068         file->private_data = pp;
1069
1070         return 0;
1071 }
1072
1073
1074 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1075 {
1076         struct smu_private *pp = misc;
1077
1078         wake_up_all(&pp->wait);
1079 }
1080
1081
1082 static ssize_t smu_write(struct file *file, const char __user *buf,
1083                          size_t count, loff_t *ppos)
1084 {
1085         struct smu_private *pp = file->private_data;
1086         unsigned long flags;
1087         struct smu_user_cmd_hdr hdr;
1088         int rc = 0;
1089
1090         if (pp->busy)
1091                 return -EBUSY;
1092         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1093                 return -EFAULT;
1094         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1095                 pp->mode = smu_file_events;
1096                 return 0;
1097         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1098                 struct smu_sdbp_header *part;
1099                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1100                 if (part == NULL)
1101                         return -EINVAL;
1102                 else if (IS_ERR(part))
1103                         return PTR_ERR(part);
1104                 return 0;
1105         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1106                 return -EINVAL;
1107         else if (pp->mode != smu_file_commands)
1108                 return -EBADFD;
1109         else if (hdr.data_len > SMU_MAX_DATA)
1110                 return -EINVAL;
1111
1112         spin_lock_irqsave(&pp->lock, flags);
1113         if (pp->busy) {
1114                 spin_unlock_irqrestore(&pp->lock, flags);
1115                 return -EBUSY;
1116         }
1117         pp->busy = 1;
1118         pp->cmd.status = 1;
1119         spin_unlock_irqrestore(&pp->lock, flags);
1120
1121         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1122                 pp->busy = 0;
1123                 return -EFAULT;
1124         }
1125
1126         pp->cmd.cmd = hdr.cmd;
1127         pp->cmd.data_len = hdr.data_len;
1128         pp->cmd.reply_len = SMU_MAX_DATA;
1129         pp->cmd.data_buf = pp->buffer;
1130         pp->cmd.reply_buf = pp->buffer;
1131         pp->cmd.done = smu_user_cmd_done;
1132         pp->cmd.misc = pp;
1133         rc = smu_queue_cmd(&pp->cmd);
1134         if (rc < 0)
1135                 return rc;
1136         return count;
1137 }
1138
1139
1140 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1141                                 char __user *buf, size_t count)
1142 {
1143         DECLARE_WAITQUEUE(wait, current);
1144         struct smu_user_reply_hdr hdr;
1145         unsigned long flags;
1146         int size, rc = 0;
1147
1148         if (!pp->busy)
1149                 return 0;
1150         if (count < sizeof(struct smu_user_reply_hdr))
1151                 return -EOVERFLOW;
1152         spin_lock_irqsave(&pp->lock, flags);
1153         if (pp->cmd.status == 1) {
1154                 if (file->f_flags & O_NONBLOCK)
1155                         return -EAGAIN;
1156                 add_wait_queue(&pp->wait, &wait);
1157                 for (;;) {
1158                         set_current_state(TASK_INTERRUPTIBLE);
1159                         rc = 0;
1160                         if (pp->cmd.status != 1)
1161                                 break;
1162                         rc = -ERESTARTSYS;
1163                         if (signal_pending(current))
1164                                 break;
1165                         spin_unlock_irqrestore(&pp->lock, flags);
1166                         schedule();
1167                         spin_lock_irqsave(&pp->lock, flags);
1168                 }
1169                 set_current_state(TASK_RUNNING);
1170                 remove_wait_queue(&pp->wait, &wait);
1171         }
1172         spin_unlock_irqrestore(&pp->lock, flags);
1173         if (rc)
1174                 return rc;
1175         if (pp->cmd.status != 0)
1176                 pp->cmd.reply_len = 0;
1177         size = sizeof(hdr) + pp->cmd.reply_len;
1178         if (count < size)
1179                 size = count;
1180         rc = size;
1181         hdr.status = pp->cmd.status;
1182         hdr.reply_len = pp->cmd.reply_len;
1183         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1184                 return -EFAULT;
1185         size -= sizeof(hdr);
1186         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1187                 return -EFAULT;
1188         pp->busy = 0;
1189
1190         return rc;
1191 }
1192
1193
1194 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1195                                char __user *buf, size_t count)
1196 {
1197         /* Not implemented */
1198         msleep_interruptible(1000);
1199         return 0;
1200 }
1201
1202
1203 static ssize_t smu_read(struct file *file, char __user *buf,
1204                         size_t count, loff_t *ppos)
1205 {
1206         struct smu_private *pp = file->private_data;
1207
1208         if (pp->mode == smu_file_commands)
1209                 return smu_read_command(file, pp, buf, count);
1210         if (pp->mode == smu_file_events)
1211                 return smu_read_events(file, pp, buf, count);
1212
1213         return -EBADFD;
1214 }
1215
1216 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1217 {
1218         struct smu_private *pp = file->private_data;
1219         unsigned int mask = 0;
1220         unsigned long flags;
1221
1222         if (pp == 0)
1223                 return 0;
1224
1225         if (pp->mode == smu_file_commands) {
1226                 poll_wait(file, &pp->wait, wait);
1227
1228                 spin_lock_irqsave(&pp->lock, flags);
1229                 if (pp->busy && pp->cmd.status != 1)
1230                         mask |= POLLIN;
1231                 spin_unlock_irqrestore(&pp->lock, flags);
1232         } if (pp->mode == smu_file_events) {
1233                 /* Not yet implemented */
1234         }
1235         return mask;
1236 }
1237
1238 static int smu_release(struct inode *inode, struct file *file)
1239 {
1240         struct smu_private *pp = file->private_data;
1241         unsigned long flags;
1242         unsigned int busy;
1243
1244         if (pp == 0)
1245                 return 0;
1246
1247         file->private_data = NULL;
1248
1249         /* Mark file as closing to avoid races with new request */
1250         spin_lock_irqsave(&pp->lock, flags);
1251         pp->mode = smu_file_closing;
1252         busy = pp->busy;
1253
1254         /* Wait for any pending request to complete */
1255         if (busy && pp->cmd.status == 1) {
1256                 DECLARE_WAITQUEUE(wait, current);
1257
1258                 add_wait_queue(&pp->wait, &wait);
1259                 for (;;) {
1260                         set_current_state(TASK_UNINTERRUPTIBLE);
1261                         if (pp->cmd.status != 1)
1262                                 break;
1263                         spin_lock_irqsave(&pp->lock, flags);
1264                         schedule();
1265                         spin_unlock_irqrestore(&pp->lock, flags);
1266                 }
1267                 set_current_state(TASK_RUNNING);
1268                 remove_wait_queue(&pp->wait, &wait);
1269         }
1270         spin_unlock_irqrestore(&pp->lock, flags);
1271
1272         spin_lock_irqsave(&smu_clist_lock, flags);
1273         list_del(&pp->list);
1274         spin_unlock_irqrestore(&smu_clist_lock, flags);
1275         kfree(pp);
1276
1277         return 0;
1278 }
1279
1280
1281 static struct file_operations smu_device_fops = {
1282         .llseek         = no_llseek,
1283         .read           = smu_read,
1284         .write          = smu_write,
1285         .poll           = smu_fpoll,
1286         .open           = smu_open,
1287         .release        = smu_release,
1288 };
1289
1290 static struct miscdevice pmu_device = {
1291         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1292 };
1293
1294 static int smu_device_init(void)
1295 {
1296         if (!smu)
1297                 return -ENODEV;
1298         if (misc_register(&pmu_device) < 0)
1299                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1300         return 0;
1301 }
1302 device_initcall(smu_device_init);