drivers/macintosh/smu.c

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