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 #include <asm/of_platform.h>
  50
  51 #define VERSION "0.7"
  52 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  53
  54 #undef DEBUG_SMU
  55
  56 #ifdef DEBUG_SMU
  57 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  58 #else
  59 #define DPRINTK(fmt, args...) do { } while (0)
  60 #endif
  61
  62 /*
  63  * This is the command buffer passed to the SMU hardware
  64  */
  65 #define SMU_MAX_DATA    254
  66
  67 struct smu_cmd_buf {
  68         u8 cmd;
  69         u8 length;
  70         u8 data[SMU_MAX_DATA];
  71 };
  72
  73 struct smu_device {
  74         spinlock_t              lock;
  75         struct device_node      *of_node;
  76         struct of_device        *of_dev;
  77         int                     doorbell;       /* doorbell gpio */
  78         u32 __iomem             *db_buf;        /* doorbell buffer */
  79         struct device_node      *db_node;
  80         unsigned int            db_irq;
  81         int                     msg;
  82         struct device_node      *msg_node;
  83         unsigned int            msg_irq;
  84         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  85         u32                     cmd_buf_abs;    /* command buffer absolute */
  86         struct list_head        cmd_list;
  87         struct smu_cmd          *cmd_cur;       /* pending command */
  88         struct list_head        cmd_i2c_list;
  89         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  90         struct timer_list       i2c_timer;
  91 };
  92
  93 /*
  94  * I don't think there will ever be more than one SMU, so
  95  * for now, just hard code that
  96  */
  97 static struct smu_device        *smu;
  98 static DEFINE_MUTEX(smu_part_access);
  99 static int smu_irq_inited;
 100
 101 static void smu_i2c_retry(unsigned long data);
 102
 103 /*
 104  * SMU driver low level stuff
 105  */
 106
 107 static void smu_start_cmd(void)
 108 {
 109         unsigned long faddr, fend;
 110         struct smu_cmd *cmd;
 111
 112         if (list_empty(&smu->cmd_list))
 113                 return;
 114
 115         /* Fetch first command in queue */
 116         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 117         smu->cmd_cur = cmd;
 118         list_del(&cmd->link);
 119
 120         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 121                 cmd->data_len);
 122         DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 123                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 124                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 125                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 126                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 127
 128         /* Fill the SMU command buffer */
 129         smu->cmd_buf->cmd = cmd->cmd;
 130         smu->cmd_buf->length = cmd->data_len;
 131         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 132
 133         /* Flush command and data to RAM */
 134         faddr = (unsigned long)smu->cmd_buf;
 135         fend = faddr + smu->cmd_buf->length + 2;
 136         flush_inval_dcache_range(faddr, fend);
 137
 138         /* This isn't exactly a DMA mapping here, I suspect
 139          * the SMU is actually communicating with us via i2c to the
 140          * northbridge or the CPU to access RAM.
 141          */
 142         writel(smu->cmd_buf_abs, smu->db_buf);
 143
 144         /* Ring the SMU doorbell */
 145         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 146 }
 147
 148
 149 static irqreturn_t smu_db_intr(int irq, void *arg)
 150 {
 151         unsigned long flags;
 152         struct smu_cmd *cmd;
 153         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 154         void *misc = NULL;
 155         u8 gpio;
 156         int rc = 0;
 157
 158         /* SMU completed the command, well, we hope, let's make sure
 159          * of it
 160          */
 161         spin_lock_irqsave(&smu->lock, flags);
 162
 163         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 164         if ((gpio & 7) != 7) {
 165                 spin_unlock_irqrestore(&smu->lock, flags);
 166                 return IRQ_HANDLED;
 167         }
 168
 169         cmd = smu->cmd_cur;
 170         smu->cmd_cur = NULL;
 171         if (cmd == NULL)
 172                 goto bail;
 173
 174         if (rc == 0) {
 175                 unsigned long faddr;
 176                 int reply_len;
 177                 u8 ack;
 178
 179                 /* CPU might have brought back the cache line, so we need
 180                  * to flush again before peeking at the SMU response. We
 181                  * flush the entire buffer for now as we haven't read the
 182                  * reply lenght (it's only 2 cache lines anyway)
 183                  */
 184                 faddr = (unsigned long)smu->cmd_buf;
 185                 flush_inval_dcache_range(faddr, faddr + 256);
 186
 187                 /* Now check ack */
 188                 ack = (~cmd->cmd) & 0xff;
 189                 if (ack != smu->cmd_buf->cmd) {
 190                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 191                                 ack, smu->cmd_buf->cmd);
 192                         rc = -EIO;
 193                 }
 194                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 195                 DPRINTK("SMU: reply len: %d\n", reply_len);
 196                 if (reply_len > cmd->reply_len) {
 197                         printk(KERN_WARNING "SMU: reply buffer too small,"
 198                                "got %d bytes for a %d bytes buffer\n",
 199                                reply_len, cmd->reply_len);
 200                         reply_len = cmd->reply_len;
 201                 }
 202                 cmd->reply_len = reply_len;
 203                 if (cmd->reply_buf && reply_len)
 204                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 205         }
 206
 207         /* Now complete the command. Write status last in order as we lost
 208          * ownership of the command structure as soon as it's no longer -1
 209          */
 210         done = cmd->done;
 211         misc = cmd->misc;
 212         mb();
 213         cmd->status = rc;
 214  bail:
 215         /* Start next command if any */
 216         smu_start_cmd();
 217         spin_unlock_irqrestore(&smu->lock, flags);
 218
 219         /* Call command completion handler if any */
 220         if (done)
 221                 done(cmd, misc);
 222
 223         /* It's an edge interrupt, nothing to do */
 224         return IRQ_HANDLED;
 225 }
 226
 227
 228 static irqreturn_t smu_msg_intr(int irq, void *arg)
 229 {
 230         /* I don't quite know what to do with this one, we seem to never
 231          * receive it, so I suspect we have to arm it someway in the SMU
 232          * to start getting events that way.
 233          */
 234
 235         printk(KERN_INFO "SMU: message interrupt !\n");
 236
 237         /* It's an edge interrupt, nothing to do */
 238         return IRQ_HANDLED;
 239 }
 240
 241
 242 /*
 243  * Queued command management.
 244  *
 245  */
 246
 247 int smu_queue_cmd(struct smu_cmd *cmd)
 248 {
 249         unsigned long flags;
 250
 251         if (smu == NULL)
 252                 return -ENODEV;
 253         if (cmd->data_len > SMU_MAX_DATA ||
 254             cmd->reply_len > SMU_MAX_DATA)
 255                 return -EINVAL;
 256
 257         cmd->status = 1;
 258         spin_lock_irqsave(&smu->lock, flags);
 259         list_add_tail(&cmd->link, &smu->cmd_list);
 260         if (smu->cmd_cur == NULL)
 261                 smu_start_cmd();
 262         spin_unlock_irqrestore(&smu->lock, flags);
 263
 264         /* Workaround for early calls when irq isn't available */
 265         if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 266                 smu_spinwait_cmd(cmd);
 267
 268         return 0;
 269 }
 270 EXPORT_SYMBOL(smu_queue_cmd);
 271
 272
 273 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 274                      unsigned int data_len,
 275                      void (*done)(struct smu_cmd *cmd, void *misc),
 276                      void *misc, ...)
 277 {
 278         struct smu_cmd *cmd = &scmd->cmd;
 279         va_list list;
 280         int i;
 281
 282         if (data_len > sizeof(scmd->buffer))
 283                 return -EINVAL;
 284
 285         memset(scmd, 0, sizeof(*scmd));
 286         cmd->cmd = command;
 287         cmd->data_len = data_len;
 288         cmd->data_buf = scmd->buffer;
 289         cmd->reply_len = sizeof(scmd->buffer);
 290         cmd->reply_buf = scmd->buffer;
 291         cmd->done = done;
 292         cmd->misc = misc;
 293
 294         va_start(list, misc);
 295         for (i = 0; i < data_len; ++i)
 296                 scmd->buffer[i] = (u8)va_arg(list, int);
 297         va_end(list);
 298
 299         return smu_queue_cmd(cmd);
 300 }
 301 EXPORT_SYMBOL(smu_queue_simple);
 302
 303
 304 void smu_poll(void)
 305 {
 306         u8 gpio;
 307
 308         if (smu == NULL)
 309                 return;
 310
 311         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 312         if ((gpio & 7) == 7)
 313                 smu_db_intr(smu->db_irq, smu);
 314 }
 315 EXPORT_SYMBOL(smu_poll);
 316
 317
 318 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 319 {
 320         struct completion *comp = misc;
 321
 322         complete(comp);
 323 }
 324 EXPORT_SYMBOL(smu_done_complete);
 325
 326
 327 void smu_spinwait_cmd(struct smu_cmd *cmd)
 328 {
 329         while(cmd->status == 1)
 330                 smu_poll();
 331 }
 332 EXPORT_SYMBOL(smu_spinwait_cmd);
 333
 334
 335 /* RTC low level commands */
 336 static inline int bcd2hex (int n)
 337 {
 338         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 339 }
 340
 341
 342 static inline int hex2bcd (int n)
 343 {
 344         return ((n / 10) << 4) + (n % 10);
 345 }
 346
 347
 348 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 349                                         struct rtc_time *time)
 350 {
 351         cmd_buf->cmd = 0x8e;
 352         cmd_buf->length = 8;
 353         cmd_buf->data[0] = 0x80;
 354         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 355         cmd_buf->data[2] = hex2bcd(time->tm_min);
 356         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 357         cmd_buf->data[4] = time->tm_wday;
 358         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 359         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 360         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 361 }
 362
 363
 364 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 365 {
 366         struct smu_simple_cmd cmd;
 367         int rc;
 368
 369         if (smu == NULL)
 370                 return -ENODEV;
 371
 372         memset(time, 0, sizeof(struct rtc_time));
 373         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 374                               SMU_CMD_RTC_GET_DATETIME);
 375         if (rc)
 376                 return rc;
 377         smu_spinwait_simple(&cmd);
 378
 379         time->tm_sec = bcd2hex(cmd.buffer[0]);
 380         time->tm_min = bcd2hex(cmd.buffer[1]);
 381         time->tm_hour = bcd2hex(cmd.buffer[2]);
 382         time->tm_wday = bcd2hex(cmd.buffer[3]);
 383         time->tm_mday = bcd2hex(cmd.buffer[4]);
 384         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 385         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 386
 387         return 0;
 388 }
 389
 390
 391 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 392 {
 393         struct smu_simple_cmd cmd;
 394         int rc;
 395
 396         if (smu == NULL)
 397                 return -ENODEV;
 398
 399         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 400                               SMU_CMD_RTC_SET_DATETIME,
 401                               hex2bcd(time->tm_sec),
 402                               hex2bcd(time->tm_min),
 403                               hex2bcd(time->tm_hour),
 404                               time->tm_wday,
 405                               hex2bcd(time->tm_mday),
 406                               hex2bcd(time->tm_mon) + 1,
 407                               hex2bcd(time->tm_year - 100));
 408         if (rc)
 409                 return rc;
 410         smu_spinwait_simple(&cmd);
 411
 412         return 0;
 413 }
 414
 415
 416 void smu_shutdown(void)
 417 {
 418         struct smu_simple_cmd cmd;
 419
 420         if (smu == NULL)
 421                 return;
 422
 423         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 424                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 425                 return;
 426         smu_spinwait_simple(&cmd);
 427         for (;;)
 428                 ;
 429 }
 430
 431
 432 void smu_restart(void)
 433 {
 434         struct smu_simple_cmd cmd;
 435
 436         if (smu == NULL)
 437                 return;
 438
 439         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 440                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 441                 return;
 442         smu_spinwait_simple(&cmd);
 443         for (;;)
 444                 ;
 445 }
 446
 447
 448 int smu_present(void)
 449 {
 450         return smu != NULL;
 451 }
 452 EXPORT_SYMBOL(smu_present);
 453
 454
 455 int __init smu_init (void)
 456 {
 457         struct device_node *np;
 458         const u32 *data;
 459
 460         np = of_find_node_by_type(NULL, "smu");
 461         if (np == NULL)
 462                 return -ENODEV;
 463
 464         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
 465
 466         if (smu_cmdbuf_abs == 0) {
 467                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 468                 return -EINVAL;
 469         }
 470
 471         smu = alloc_bootmem(sizeof(struct smu_device));
 472         if (smu == NULL)
 473                 return -ENOMEM;
 474         memset(smu, 0, sizeof(*smu));
 475
 476         spin_lock_init(&smu->lock);
 477         INIT_LIST_HEAD(&smu->cmd_list);
 478         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 479         smu->of_node = np;
 480         smu->db_irq = NO_IRQ;
 481         smu->msg_irq = NO_IRQ;
 482
 483         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 484          * 32 bits value safely
 485          */
 486         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 487         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 488
 489         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 490         if (smu->db_node == NULL) {
 491                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 492                 goto fail;
 493         }
 494         data = of_get_property(smu->db_node, "reg", NULL);
 495         if (data == NULL) {
 496                 of_node_put(smu->db_node);
 497                 smu->db_node = NULL;
 498                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 499                 goto fail;
 500         }
 501
 502         /* Current setup has one doorbell GPIO that does both doorbell
 503          * and ack. GPIOs are at 0x50, best would be to find that out
 504          * in the device-tree though.
 505          */
 506         smu->doorbell = *data;
 507         if (smu->doorbell < 0x50)
 508                 smu->doorbell += 0x50;
 509
 510         /* Now look for the smu-interrupt GPIO */
 511         do {
 512                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 513                 if (smu->msg_node == NULL)
 514                         break;
 515                 data = of_get_property(smu->msg_node, "reg", NULL);
 516                 if (data == NULL) {
 517                         of_node_put(smu->msg_node);
 518                         smu->msg_node = NULL;
 519                         break;
 520                 }
 521                 smu->msg = *data;
 522                 if (smu->msg < 0x50)
 523                         smu->msg += 0x50;
 524         } while(0);
 525
 526         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 527          * device-tree entry giving the address. Best would probably to use
 528          * an offset for K2 base though, but let's do it that way for now.
 529          */
 530         smu->db_buf = ioremap(0x8000860c, 0x1000);
 531         if (smu->db_buf == NULL) {
 532                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 533                 goto fail;
 534         }
 535
 536         sys_ctrler = SYS_CTRLER_SMU;
 537         return 0;
 538
 539  fail:
 540         smu = NULL;
 541         return -ENXIO;
 542
 543 }
 544
 545
 546 static int smu_late_init(void)
 547 {
 548         if (!smu)
 549                 return 0;
 550
 551         init_timer(&smu->i2c_timer);
 552         smu->i2c_timer.function = smu_i2c_retry;
 553         smu->i2c_timer.data = (unsigned long)smu;
 554
 555         if (smu->db_node) {
 556                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 557                 if (smu->db_irq == NO_IRQ)
 558                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 559                                smu->db_node->full_name);
 560         }
 561         if (smu->msg_node) {
 562                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 563                 if (smu->msg_irq == NO_IRQ)
 564                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 565                                smu->msg_node->full_name);
 566         }
 567
 568         /*
 569          * Try to request the interrupts
 570          */
 571
 572         if (smu->db_irq != NO_IRQ) {
 573                 if (request_irq(smu->db_irq, smu_db_intr,
 574                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 575                         printk(KERN_WARNING "SMU: can't "
 576                                "request interrupt %d\n",
 577                                smu->db_irq);
 578                         smu->db_irq = NO_IRQ;
 579                 }
 580         }
 581
 582         if (smu->msg_irq != NO_IRQ) {
 583                 if (request_irq(smu->msg_irq, smu_msg_intr,
 584                                 IRQF_SHARED, "SMU message", smu) < 0) {
 585                         printk(KERN_WARNING "SMU: can't "
 586                                "request interrupt %d\n",
 587                                smu->msg_irq);
 588                         smu->msg_irq = NO_IRQ;
 589                 }
 590         }
 591
 592         smu_irq_inited = 1;
 593         return 0;
 594 }
 595 /* This has to be before arch_initcall as the low i2c stuff relies on the
 596  * above having been done before we reach arch_initcalls
 597  */
 598 core_initcall(smu_late_init);
 599
 600 /*
 601  * sysfs visibility
 602  */
 603
 604 static void smu_expose_childs(struct work_struct *unused)
 605 {
 606         struct device_node *np;
 607
 608         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 609                 if (of_device_is_compatible(np, "smu-sensors"))
 610                         of_platform_device_create(np, "smu-sensors",
 611                                                   &smu->of_dev->dev);
 612 }
 613
 614 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 615
 616 static int smu_platform_probe(struct of_device* dev,
 617                               const struct of_device_id *match)
 618 {
 619         if (!smu)
 620                 return -ENODEV;
 621         smu->of_dev = dev;
 622
 623         /*
 624          * Ok, we are matched, now expose all i2c busses. We have to defer
 625          * that unfortunately or it would deadlock inside the device model
 626          */
 627         schedule_work(&smu_expose_childs_work);
 628
 629         return 0;
 630 }
 631
 632 static struct of_device_id smu_platform_match[] =
 633 {
 634         {
 635                 .type           = "smu",
 636         },
 637         {},
 638 };
 639
 640 static struct of_platform_driver smu_of_platform_driver =
 641 {
 642         .name           = "smu",
 643         .match_table    = smu_platform_match,
 644         .probe          = smu_platform_probe,
 645 };
 646
 647 static int __init smu_init_sysfs(void)
 648 {
 649         /*
 650          * Due to sysfs bogosity, a sysdev is not a real device, so
 651          * we should in fact create both if we want sysdev semantics
 652          * for power management.
 653          * For now, we don't power manage machines with an SMU chip,
 654          * I'm a bit too far from figuring out how that works with those
 655          * new chipsets, but that will come back and bite us
 656          */
 657         of_register_platform_driver(&smu_of_platform_driver);
 658         return 0;
 659 }
 660
 661 device_initcall(smu_init_sysfs);
 662
 663 struct of_device *smu_get_ofdev(void)
 664 {
 665         if (!smu)
 666                 return NULL;
 667         return smu->of_dev;
 668 }
 669
 670 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 671
 672 /*
 673  * i2c interface
 674  */
 675
 676 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 677 {
 678         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 679         void *misc = cmd->misc;
 680         unsigned long flags;
 681
 682         /* Check for read case */
 683         if (!fail && cmd->read) {
 684                 if (cmd->pdata[0] < 1)
 685                         fail = 1;
 686                 else
 687                         memcpy(cmd->info.data, &cmd->pdata[1],
 688                                cmd->info.datalen);
 689         }
 690
 691         DPRINTK("SMU: completing, success: %d\n", !fail);
 692
 693         /* Update status and mark no pending i2c command with lock
 694          * held so nobody comes in while we dequeue an eventual
 695          * pending next i2c command
 696          */
 697         spin_lock_irqsave(&smu->lock, flags);
 698         smu->cmd_i2c_cur = NULL;
 699         wmb();
 700         cmd->status = fail ? -EIO : 0;
 701
 702         /* Is there another i2c command waiting ? */
 703         if (!list_empty(&smu->cmd_i2c_list)) {
 704                 struct smu_i2c_cmd *newcmd;
 705
 706                 /* Fetch it, new current, remove from list */
 707                 newcmd = list_entry(smu->cmd_i2c_list.next,
 708                                     struct smu_i2c_cmd, link);
 709                 smu->cmd_i2c_cur = newcmd;
 710                 list_del(&cmd->link);
 711
 712                 /* Queue with low level smu */
 713                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 714                 if (smu->cmd_cur == NULL)
 715                         smu_start_cmd();
 716         }
 717         spin_unlock_irqrestore(&smu->lock, flags);
 718
 719         /* Call command completion handler if any */
 720         if (done)
 721                 done(cmd, misc);
 722
 723 }
 724
 725
 726 static void smu_i2c_retry(unsigned long data)
 727 {
 728         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 729
 730         DPRINTK("SMU: i2c failure, requeuing...\n");
 731
 732         /* requeue command simply by resetting reply_len */
 733         cmd->pdata[0] = 0xff;
 734         cmd->scmd.reply_len = sizeof(cmd->pdata);
 735         smu_queue_cmd(&cmd->scmd);
 736 }
 737
 738
 739 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 740 {
 741         struct smu_i2c_cmd      *cmd = misc;
 742         int                     fail = 0;
 743
 744         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 745                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 746
 747         /* Check for possible status */
 748         if (scmd->status < 0)
 749                 fail = 1;
 750         else if (cmd->read) {
 751                 if (cmd->stage == 0)
 752                         fail = cmd->pdata[0] != 0;
 753                 else
 754                         fail = cmd->pdata[0] >= 0x80;
 755         } else {
 756                 fail = cmd->pdata[0] != 0;
 757         }
 758
 759         /* Handle failures by requeuing command, after 5ms interval
 760          */
 761         if (fail && --cmd->retries > 0) {
 762                 DPRINTK("SMU: i2c failure, starting timer...\n");
 763                 BUG_ON(cmd != smu->cmd_i2c_cur);
 764                 if (!smu_irq_inited) {
 765                         mdelay(5);
 766                         smu_i2c_retry(0);
 767                         return;
 768                 }
 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_ONSTACK(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_ONSTACK(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 = kzalloc(tlen, 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 = 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 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
 987                 unsigned int *size, int interruptible)
 988 {
 989         char pname[32];
 990         const 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 = mutex_lock_interruptible(&smu_part_access);
1002                 if (rc)
1003                         return ERR_PTR(rc);
1004         } else
1005                 mutex_lock(&smu_part_access);
1006
1007         part = of_get_property(smu->of_node, 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 const 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 = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1057         if (pp == 0)
1058                 return -ENOMEM;
1059         spin_lock_init(&pp->lock);
1060         pp->mode = smu_file_commands;
1061         init_waitqueue_head(&pp->wait);
1062
1063         spin_lock_irqsave(&smu_clist_lock, flags);
1064         list_add(&pp->list, &smu_clist);
1065         spin_unlock_irqrestore(&smu_clist_lock, flags);
1066         file->private_data = pp;
1067
1068         return 0;
1069 }
1070
1071
1072 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1073 {
1074         struct smu_private *pp = misc;
1075
1076         wake_up_all(&pp->wait);
1077 }
1078
1079
1080 static ssize_t smu_write(struct file *file, const char __user *buf,
1081                          size_t count, loff_t *ppos)
1082 {
1083         struct smu_private *pp = file->private_data;
1084         unsigned long flags;
1085         struct smu_user_cmd_hdr hdr;
1086         int rc = 0;
1087
1088         if (pp->busy)
1089                 return -EBUSY;
1090         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1091                 return -EFAULT;
1092         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1093                 pp->mode = smu_file_events;
1094                 return 0;
1095         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1096                 const struct smu_sdbp_header *part;
1097                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1098                 if (part == NULL)
1099                         return -EINVAL;
1100                 else if (IS_ERR(part))
1101                         return PTR_ERR(part);
1102                 return 0;
1103         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1104                 return -EINVAL;
1105         else if (pp->mode != smu_file_commands)
1106                 return -EBADFD;
1107         else if (hdr.data_len > SMU_MAX_DATA)
1108                 return -EINVAL;
1109
1110         spin_lock_irqsave(&pp->lock, flags);
1111         if (pp->busy) {
1112                 spin_unlock_irqrestore(&pp->lock, flags);
1113                 return -EBUSY;
1114         }
1115         pp->busy = 1;
1116         pp->cmd.status = 1;
1117         spin_unlock_irqrestore(&pp->lock, flags);
1118
1119         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1120                 pp->busy = 0;
1121                 return -EFAULT;
1122         }
1123
1124         pp->cmd.cmd = hdr.cmd;
1125         pp->cmd.data_len = hdr.data_len;
1126         pp->cmd.reply_len = SMU_MAX_DATA;
1127         pp->cmd.data_buf = pp->buffer;
1128         pp->cmd.reply_buf = pp->buffer;
1129         pp->cmd.done = smu_user_cmd_done;
1130         pp->cmd.misc = pp;
1131         rc = smu_queue_cmd(&pp->cmd);
1132         if (rc < 0)
1133                 return rc;
1134         return count;
1135 }
1136
1137
1138 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1139                                 char __user *buf, size_t count)
1140 {
1141         DECLARE_WAITQUEUE(wait, current);
1142         struct smu_user_reply_hdr hdr;
1143         unsigned long flags;
1144         int size, rc = 0;
1145
1146         if (!pp->busy)
1147                 return 0;
1148         if (count < sizeof(struct smu_user_reply_hdr))
1149                 return -EOVERFLOW;
1150         spin_lock_irqsave(&pp->lock, flags);
1151         if (pp->cmd.status == 1) {
1152                 if (file->f_flags & O_NONBLOCK)
1153                         return -EAGAIN;
1154                 add_wait_queue(&pp->wait, &wait);
1155                 for (;;) {
1156                         set_current_state(TASK_INTERRUPTIBLE);
1157                         rc = 0;
1158                         if (pp->cmd.status != 1)
1159                                 break;
1160                         rc = -ERESTARTSYS;
1161                         if (signal_pending(current))
1162                                 break;
1163                         spin_unlock_irqrestore(&pp->lock, flags);
1164                         schedule();
1165                         spin_lock_irqsave(&pp->lock, flags);
1166                 }
1167                 set_current_state(TASK_RUNNING);
1168                 remove_wait_queue(&pp->wait, &wait);
1169         }
1170         spin_unlock_irqrestore(&pp->lock, flags);
1171         if (rc)
1172                 return rc;
1173         if (pp->cmd.status != 0)
1174                 pp->cmd.reply_len = 0;
1175         size = sizeof(hdr) + pp->cmd.reply_len;
1176         if (count < size)
1177                 size = count;
1178         rc = size;
1179         hdr.status = pp->cmd.status;
1180         hdr.reply_len = pp->cmd.reply_len;
1181         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1182                 return -EFAULT;
1183         size -= sizeof(hdr);
1184         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1185                 return -EFAULT;
1186         pp->busy = 0;
1187
1188         return rc;
1189 }
1190
1191
1192 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1193                                char __user *buf, size_t count)
1194 {
1195         /* Not implemented */
1196         msleep_interruptible(1000);
1197         return 0;
1198 }
1199
1200
1201 static ssize_t smu_read(struct file *file, char __user *buf,
1202                         size_t count, loff_t *ppos)
1203 {
1204         struct smu_private *pp = file->private_data;
1205
1206         if (pp->mode == smu_file_commands)
1207                 return smu_read_command(file, pp, buf, count);
1208         if (pp->mode == smu_file_events)
1209                 return smu_read_events(file, pp, buf, count);
1210
1211         return -EBADFD;
1212 }
1213
1214 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1215 {
1216         struct smu_private *pp = file->private_data;
1217         unsigned int mask = 0;
1218         unsigned long flags;
1219
1220         if (pp == 0)
1221                 return 0;
1222
1223         if (pp->mode == smu_file_commands) {
1224                 poll_wait(file, &pp->wait, wait);
1225
1226                 spin_lock_irqsave(&pp->lock, flags);
1227                 if (pp->busy && pp->cmd.status != 1)
1228                         mask |= POLLIN;
1229                 spin_unlock_irqrestore(&pp->lock, flags);
1230         } if (pp->mode == smu_file_events) {
1231                 /* Not yet implemented */
1232         }
1233         return mask;
1234 }
1235
1236 static int smu_release(struct inode *inode, struct file *file)
1237 {
1238         struct smu_private *pp = file->private_data;
1239         unsigned long flags;
1240         unsigned int busy;
1241
1242         if (pp == 0)
1243                 return 0;
1244
1245         file->private_data = NULL;
1246
1247         /* Mark file as closing to avoid races with new request */
1248         spin_lock_irqsave(&pp->lock, flags);
1249         pp->mode = smu_file_closing;
1250         busy = pp->busy;
1251
1252         /* Wait for any pending request to complete */
1253         if (busy && pp->cmd.status == 1) {
1254                 DECLARE_WAITQUEUE(wait, current);
1255
1256                 add_wait_queue(&pp->wait, &wait);
1257                 for (;;) {
1258                         set_current_state(TASK_UNINTERRUPTIBLE);
1259                         if (pp->cmd.status != 1)
1260                                 break;
1261                         spin_unlock_irqrestore(&pp->lock, flags);
1262                         schedule();
1263                         spin_lock_irqsave(&pp->lock, flags);
1264                 }
1265                 set_current_state(TASK_RUNNING);
1266                 remove_wait_queue(&pp->wait, &wait);
1267         }
1268         spin_unlock_irqrestore(&pp->lock, flags);
1269
1270         spin_lock_irqsave(&smu_clist_lock, flags);
1271         list_del(&pp->list);
1272         spin_unlock_irqrestore(&smu_clist_lock, flags);
1273         kfree(pp);
1274
1275         return 0;
1276 }
1277
1278
1279 static const struct file_operations smu_device_fops = {
1280         .llseek         = no_llseek,
1281         .read           = smu_read,
1282         .write          = smu_write,
1283         .poll           = smu_fpoll,
1284         .open           = smu_open,
1285         .release        = smu_release,
1286 };
1287
1288 static struct miscdevice pmu_device = {
1289         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1290 };
1291
1292 static int smu_device_init(void)
1293 {
1294         if (!smu)
1295                 return -ENODEV;
1296         if (misc_register(&pmu_device) < 0)
1297                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1298         return 0;
1299 }
1300 device_initcall(smu_device_init);