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  *    interrupts 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/poll.h>
  36 #include <linux/mutex.h>
  37 #include <linux/of_device.h>
  38 #include <linux/of_irq.h>
  39 #include <linux/of_platform.h>
  40 #include <linux/slab.h>
  41
  42 #include <asm/byteorder.h>
  43 #include <asm/io.h>
  44 #include <asm/prom.h>
  45 #include <asm/machdep.h>
  46 #include <asm/pmac_feature.h>
  47 #include <asm/smu.h>
  48 #include <asm/sections.h>
  49 #include <asm/uaccess.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 platform_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         int                     broken_nap;
  89         struct list_head        cmd_i2c_list;
  90         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  91         struct timer_list       i2c_timer;
  92 };
  93
  94 /*
  95  * I don't think there will ever be more than one SMU, so
  96  * for now, just hard code that
  97  */
  98 static DEFINE_MUTEX(smu_mutex);
  99 static struct smu_device        *smu;
 100 static DEFINE_MUTEX(smu_part_access);
 101 static int smu_irq_inited;
 102
 103 static void smu_i2c_retry(unsigned long data);
 104
 105 /*
 106  * SMU driver low level stuff
 107  */
 108
 109 static void smu_start_cmd(void)
 110 {
 111         unsigned long faddr, fend;
 112         struct smu_cmd *cmd;
 113
 114         if (list_empty(&smu->cmd_list))
 115                 return;
 116
 117         /* Fetch first command in queue */
 118         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 119         smu->cmd_cur = cmd;
 120         list_del(&cmd->link);
 121
 122         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 123                 cmd->data_len);
 124         DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf);
 125
 126         /* Fill the SMU command buffer */
 127         smu->cmd_buf->cmd = cmd->cmd;
 128         smu->cmd_buf->length = cmd->data_len;
 129         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 130
 131         /* Flush command and data to RAM */
 132         faddr = (unsigned long)smu->cmd_buf;
 133         fend = faddr + smu->cmd_buf->length + 2;
 134         flush_inval_dcache_range(faddr, fend);
 135
 136
 137         /* We also disable NAP mode for the duration of the command
 138          * on U3 based machines.
 139          * This is slightly racy as it can be written back to 1 by a sysctl
 140          * but that never happens in practice. There seem to be an issue with
 141          * U3 based machines such as the iMac G5 where napping for the
 142          * whole duration of the command prevents the SMU from fetching it
 143          * from memory. This might be related to the strange i2c based
 144          * mechanism the SMU uses to access memory.
 145          */
 146         if (smu->broken_nap)
 147                 powersave_nap = 0;
 148
 149         /* This isn't exactly a DMA mapping here, I suspect
 150          * the SMU is actually communicating with us via i2c to the
 151          * northbridge or the CPU to access RAM.
 152          */
 153         writel(smu->cmd_buf_abs, smu->db_buf);
 154
 155         /* Ring the SMU doorbell */
 156         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 157 }
 158
 159
 160 static irqreturn_t smu_db_intr(int irq, void *arg)
 161 {
 162         unsigned long flags;
 163         struct smu_cmd *cmd;
 164         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 165         void *misc = NULL;
 166         u8 gpio;
 167         int rc = 0;
 168
 169         /* SMU completed the command, well, we hope, let's make sure
 170          * of it
 171          */
 172         spin_lock_irqsave(&smu->lock, flags);
 173
 174         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 175         if ((gpio & 7) != 7) {
 176                 spin_unlock_irqrestore(&smu->lock, flags);
 177                 return IRQ_HANDLED;
 178         }
 179
 180         cmd = smu->cmd_cur;
 181         smu->cmd_cur = NULL;
 182         if (cmd == NULL)
 183                 goto bail;
 184
 185         if (rc == 0) {
 186                 unsigned long faddr;
 187                 int reply_len;
 188                 u8 ack;
 189
 190                 /* CPU might have brought back the cache line, so we need
 191                  * to flush again before peeking at the SMU response. We
 192                  * flush the entire buffer for now as we haven't read the
 193                  * reply length (it's only 2 cache lines anyway)
 194                  */
 195                 faddr = (unsigned long)smu->cmd_buf;
 196                 flush_inval_dcache_range(faddr, faddr + 256);
 197
 198                 /* Now check ack */
 199                 ack = (~cmd->cmd) & 0xff;
 200                 if (ack != smu->cmd_buf->cmd) {
 201                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 202                                 ack, smu->cmd_buf->cmd);
 203                         rc = -EIO;
 204                 }
 205                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 206                 DPRINTK("SMU: reply len: %d\n", reply_len);
 207                 if (reply_len > cmd->reply_len) {
 208                         printk(KERN_WARNING "SMU: reply buffer too small,"
 209                                "got %d bytes for a %d bytes buffer\n",
 210                                reply_len, cmd->reply_len);
 211                         reply_len = cmd->reply_len;
 212                 }
 213                 cmd->reply_len = reply_len;
 214                 if (cmd->reply_buf && reply_len)
 215                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 216         }
 217
 218         /* Now complete the command. Write status last in order as we lost
 219          * ownership of the command structure as soon as it's no longer -1
 220          */
 221         done = cmd->done;
 222         misc = cmd->misc;
 223         mb();
 224         cmd->status = rc;
 225
 226         /* Re-enable NAP mode */
 227         if (smu->broken_nap)
 228                 powersave_nap = 1;
 229  bail:
 230         /* Start next command if any */
 231         smu_start_cmd();
 232         spin_unlock_irqrestore(&smu->lock, flags);
 233
 234         /* Call command completion handler if any */
 235         if (done)
 236                 done(cmd, misc);
 237
 238         /* It's an edge interrupt, nothing to do */
 239         return IRQ_HANDLED;
 240 }
 241
 242
 243 static irqreturn_t smu_msg_intr(int irq, void *arg)
 244 {
 245         /* I don't quite know what to do with this one, we seem to never
 246          * receive it, so I suspect we have to arm it someway in the SMU
 247          * to start getting events that way.
 248          */
 249
 250         printk(KERN_INFO "SMU: message interrupt !\n");
 251
 252         /* It's an edge interrupt, nothing to do */
 253         return IRQ_HANDLED;
 254 }
 255
 256
 257 /*
 258  * Queued command management.
 259  *
 260  */
 261
 262 int smu_queue_cmd(struct smu_cmd *cmd)
 263 {
 264         unsigned long flags;
 265
 266         if (smu == NULL)
 267                 return -ENODEV;
 268         if (cmd->data_len > SMU_MAX_DATA ||
 269             cmd->reply_len > SMU_MAX_DATA)
 270                 return -EINVAL;
 271
 272         cmd->status = 1;
 273         spin_lock_irqsave(&smu->lock, flags);
 274         list_add_tail(&cmd->link, &smu->cmd_list);
 275         if (smu->cmd_cur == NULL)
 276                 smu_start_cmd();
 277         spin_unlock_irqrestore(&smu->lock, flags);
 278
 279         /* Workaround for early calls when irq isn't available */
 280         if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 281                 smu_spinwait_cmd(cmd);
 282
 283         return 0;
 284 }
 285 EXPORT_SYMBOL(smu_queue_cmd);
 286
 287
 288 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 289                      unsigned int data_len,
 290                      void (*done)(struct smu_cmd *cmd, void *misc),
 291                      void *misc, ...)
 292 {
 293         struct smu_cmd *cmd = &scmd->cmd;
 294         va_list list;
 295         int i;
 296
 297         if (data_len > sizeof(scmd->buffer))
 298                 return -EINVAL;
 299
 300         memset(scmd, 0, sizeof(*scmd));
 301         cmd->cmd = command;
 302         cmd->data_len = data_len;
 303         cmd->data_buf = scmd->buffer;
 304         cmd->reply_len = sizeof(scmd->buffer);
 305         cmd->reply_buf = scmd->buffer;
 306         cmd->done = done;
 307         cmd->misc = misc;
 308
 309         va_start(list, misc);
 310         for (i = 0; i < data_len; ++i)
 311                 scmd->buffer[i] = (u8)va_arg(list, int);
 312         va_end(list);
 313
 314         return smu_queue_cmd(cmd);
 315 }
 316 EXPORT_SYMBOL(smu_queue_simple);
 317
 318
 319 void smu_poll(void)
 320 {
 321         u8 gpio;
 322
 323         if (smu == NULL)
 324                 return;
 325
 326         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 327         if ((gpio & 7) == 7)
 328                 smu_db_intr(smu->db_irq, smu);
 329 }
 330 EXPORT_SYMBOL(smu_poll);
 331
 332
 333 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 334 {
 335         struct completion *comp = misc;
 336
 337         complete(comp);
 338 }
 339 EXPORT_SYMBOL(smu_done_complete);
 340
 341
 342 void smu_spinwait_cmd(struct smu_cmd *cmd)
 343 {
 344         while(cmd->status == 1)
 345                 smu_poll();
 346 }
 347 EXPORT_SYMBOL(smu_spinwait_cmd);
 348
 349
 350 /* RTC low level commands */
 351 static inline int bcd2hex (int n)
 352 {
 353         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 354 }
 355
 356
 357 static inline int hex2bcd (int n)
 358 {
 359         return ((n / 10) << 4) + (n % 10);
 360 }
 361
 362
 363 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 364                                         struct rtc_time *time)
 365 {
 366         cmd_buf->cmd = 0x8e;
 367         cmd_buf->length = 8;
 368         cmd_buf->data[0] = 0x80;
 369         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 370         cmd_buf->data[2] = hex2bcd(time->tm_min);
 371         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 372         cmd_buf->data[4] = time->tm_wday;
 373         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 374         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 375         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 376 }
 377
 378
 379 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 380 {
 381         struct smu_simple_cmd cmd;
 382         int rc;
 383
 384         if (smu == NULL)
 385                 return -ENODEV;
 386
 387         memset(time, 0, sizeof(struct rtc_time));
 388         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 389                               SMU_CMD_RTC_GET_DATETIME);
 390         if (rc)
 391                 return rc;
 392         smu_spinwait_simple(&cmd);
 393
 394         time->tm_sec = bcd2hex(cmd.buffer[0]);
 395         time->tm_min = bcd2hex(cmd.buffer[1]);
 396         time->tm_hour = bcd2hex(cmd.buffer[2]);
 397         time->tm_wday = bcd2hex(cmd.buffer[3]);
 398         time->tm_mday = bcd2hex(cmd.buffer[4]);
 399         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 400         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 401
 402         return 0;
 403 }
 404
 405
 406 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 407 {
 408         struct smu_simple_cmd cmd;
 409         int rc;
 410
 411         if (smu == NULL)
 412                 return -ENODEV;
 413
 414         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 415                               SMU_CMD_RTC_SET_DATETIME,
 416                               hex2bcd(time->tm_sec),
 417                               hex2bcd(time->tm_min),
 418                               hex2bcd(time->tm_hour),
 419                               time->tm_wday,
 420                               hex2bcd(time->tm_mday),
 421                               hex2bcd(time->tm_mon) + 1,
 422                               hex2bcd(time->tm_year - 100));
 423         if (rc)
 424                 return rc;
 425         smu_spinwait_simple(&cmd);
 426
 427         return 0;
 428 }
 429
 430
 431 void smu_shutdown(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, 9, NULL, NULL,
 439                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 440                 return;
 441         smu_spinwait_simple(&cmd);
 442         for (;;)
 443                 ;
 444 }
 445
 446
 447 void smu_restart(void)
 448 {
 449         struct smu_simple_cmd cmd;
 450
 451         if (smu == NULL)
 452                 return;
 453
 454         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 455                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 456                 return;
 457         smu_spinwait_simple(&cmd);
 458         for (;;)
 459                 ;
 460 }
 461
 462
 463 int smu_present(void)
 464 {
 465         return smu != NULL;
 466 }
 467 EXPORT_SYMBOL(smu_present);
 468
 469
 470 int __init smu_init (void)
 471 {
 472         struct device_node *np;
 473         const u32 *data;
 474         int ret = 0;
 475
 476         np = of_find_node_by_type(NULL, "smu");
 477         if (np == NULL)
 478                 return -ENODEV;
 479
 480         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 481
 482         if (smu_cmdbuf_abs == 0) {
 483                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 484                 ret = -EINVAL;
 485                 goto fail_np;
 486         }
 487
 488         smu = alloc_bootmem(sizeof(struct smu_device));
 489
 490         spin_lock_init(&smu->lock);
 491         INIT_LIST_HEAD(&smu->cmd_list);
 492         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 493         smu->of_node = np;
 494         smu->db_irq = NO_IRQ;
 495         smu->msg_irq = NO_IRQ;
 496
 497         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 498          * 32 bits value safely
 499          */
 500         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 501         smu->cmd_buf = __va(smu_cmdbuf_abs);
 502
 503         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 504         if (smu->db_node == NULL) {
 505                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 506                 ret = -ENXIO;
 507                 goto fail_bootmem;
 508         }
 509         data = of_get_property(smu->db_node, "reg", NULL);
 510         if (data == NULL) {
 511                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 512                 ret = -ENXIO;
 513                 goto fail_db_node;
 514         }
 515
 516         /* Current setup has one doorbell GPIO that does both doorbell
 517          * and ack. GPIOs are at 0x50, best would be to find that out
 518          * in the device-tree though.
 519          */
 520         smu->doorbell = *data;
 521         if (smu->doorbell < 0x50)
 522                 smu->doorbell += 0x50;
 523
 524         /* Now look for the smu-interrupt GPIO */
 525         do {
 526                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 527                 if (smu->msg_node == NULL)
 528                         break;
 529                 data = of_get_property(smu->msg_node, "reg", NULL);
 530                 if (data == NULL) {
 531                         of_node_put(smu->msg_node);
 532                         smu->msg_node = NULL;
 533                         break;
 534                 }
 535                 smu->msg = *data;
 536                 if (smu->msg < 0x50)
 537                         smu->msg += 0x50;
 538         } while(0);
 539
 540         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 541          * device-tree entry giving the address. Best would probably to use
 542          * an offset for K2 base though, but let's do it that way for now.
 543          */
 544         smu->db_buf = ioremap(0x8000860c, 0x1000);
 545         if (smu->db_buf == NULL) {
 546                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 547                 ret = -ENXIO;
 548                 goto fail_msg_node;
 549         }
 550
 551         /* U3 has an issue with NAP mode when issuing SMU commands */
 552         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 553         if (smu->broken_nap)
 554                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 555
 556         sys_ctrler = SYS_CTRLER_SMU;
 557         return 0;
 558
 559 fail_msg_node:
 560         of_node_put(smu->msg_node);
 561 fail_db_node:
 562         of_node_put(smu->db_node);
 563 fail_bootmem:
 564         free_bootmem(__pa(smu), sizeof(struct smu_device));
 565         smu = NULL;
 566 fail_np:
 567         of_node_put(np);
 568         return ret;
 569 }
 570
 571
 572 static int smu_late_init(void)
 573 {
 574         if (!smu)
 575                 return 0;
 576
 577         init_timer(&smu->i2c_timer);
 578         smu->i2c_timer.function = smu_i2c_retry;
 579         smu->i2c_timer.data = (unsigned long)smu;
 580
 581         if (smu->db_node) {
 582                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 583                 if (smu->db_irq == NO_IRQ)
 584                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 585                                smu->db_node->full_name);
 586         }
 587         if (smu->msg_node) {
 588                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 589                 if (smu->msg_irq == NO_IRQ)
 590                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 591                                smu->msg_node->full_name);
 592         }
 593
 594         /*
 595          * Try to request the interrupts
 596          */
 597
 598         if (smu->db_irq != NO_IRQ) {
 599                 if (request_irq(smu->db_irq, smu_db_intr,
 600                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 601                         printk(KERN_WARNING "SMU: can't "
 602                                "request interrupt %d\n",
 603                                smu->db_irq);
 604                         smu->db_irq = NO_IRQ;
 605                 }
 606         }
 607
 608         if (smu->msg_irq != NO_IRQ) {
 609                 if (request_irq(smu->msg_irq, smu_msg_intr,
 610                                 IRQF_SHARED, "SMU message", smu) < 0) {
 611                         printk(KERN_WARNING "SMU: can't "
 612                                "request interrupt %d\n",
 613                                smu->msg_irq);
 614                         smu->msg_irq = NO_IRQ;
 615                 }
 616         }
 617
 618         smu_irq_inited = 1;
 619         return 0;
 620 }
 621 /* This has to be before arch_initcall as the low i2c stuff relies on the
 622  * above having been done before we reach arch_initcalls
 623  */
 624 core_initcall(smu_late_init);
 625
 626 /*
 627  * sysfs visibility
 628  */
 629
 630 static void smu_expose_childs(struct work_struct *unused)
 631 {
 632         struct device_node *np;
 633
 634         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 635                 if (of_device_is_compatible(np, "smu-sensors"))
 636                         of_platform_device_create(np, "smu-sensors",
 637                                                   &smu->of_dev->dev);
 638 }
 639
 640 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 641
 642 static int smu_platform_probe(struct platform_device* dev)
 643 {
 644         if (!smu)
 645                 return -ENODEV;
 646         smu->of_dev = dev;
 647
 648         /*
 649          * Ok, we are matched, now expose all i2c busses. We have to defer
 650          * that unfortunately or it would deadlock inside the device model
 651          */
 652         schedule_work(&smu_expose_childs_work);
 653
 654         return 0;
 655 }
 656
 657 static const struct of_device_id smu_platform_match[] =
 658 {
 659         {
 660                 .type           = "smu",
 661         },
 662         {},
 663 };
 664
 665 static struct platform_driver smu_of_platform_driver =
 666 {
 667         .driver = {
 668                 .name = "smu",
 669                 .of_match_table = smu_platform_match,
 670         },
 671         .probe          = smu_platform_probe,
 672 };
 673
 674 static int __init smu_init_sysfs(void)
 675 {
 676         /*
 677          * For now, we don't power manage machines with an SMU chip,
 678          * I'm a bit too far from figuring out how that works with those
 679          * new chipsets, but that will come back and bite us
 680          */
 681         platform_driver_register(&smu_of_platform_driver);
 682         return 0;
 683 }
 684
 685 device_initcall(smu_init_sysfs);
 686
 687 struct platform_device *smu_get_ofdev(void)
 688 {
 689         if (!smu)
 690                 return NULL;
 691         return smu->of_dev;
 692 }
 693
 694 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 695
 696 /*
 697  * i2c interface
 698  */
 699
 700 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 701 {
 702         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 703         void *misc = cmd->misc;
 704         unsigned long flags;
 705
 706         /* Check for read case */
 707         if (!fail && cmd->read) {
 708                 if (cmd->pdata[0] < 1)
 709                         fail = 1;
 710                 else
 711                         memcpy(cmd->info.data, &cmd->pdata[1],
 712                                cmd->info.datalen);
 713         }
 714
 715         DPRINTK("SMU: completing, success: %d\n", !fail);
 716
 717         /* Update status and mark no pending i2c command with lock
 718          * held so nobody comes in while we dequeue an eventual
 719          * pending next i2c command
 720          */
 721         spin_lock_irqsave(&smu->lock, flags);
 722         smu->cmd_i2c_cur = NULL;
 723         wmb();
 724         cmd->status = fail ? -EIO : 0;
 725
 726         /* Is there another i2c command waiting ? */
 727         if (!list_empty(&smu->cmd_i2c_list)) {
 728                 struct smu_i2c_cmd *newcmd;
 729
 730                 /* Fetch it, new current, remove from list */
 731                 newcmd = list_entry(smu->cmd_i2c_list.next,
 732                                     struct smu_i2c_cmd, link);
 733                 smu->cmd_i2c_cur = newcmd;
 734                 list_del(&cmd->link);
 735
 736                 /* Queue with low level smu */
 737                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 738                 if (smu->cmd_cur == NULL)
 739                         smu_start_cmd();
 740         }
 741         spin_unlock_irqrestore(&smu->lock, flags);
 742
 743         /* Call command completion handler if any */
 744         if (done)
 745                 done(cmd, misc);
 746
 747 }
 748
 749
 750 static void smu_i2c_retry(unsigned long data)
 751 {
 752         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 753
 754         DPRINTK("SMU: i2c failure, requeuing...\n");
 755
 756         /* requeue command simply by resetting reply_len */
 757         cmd->pdata[0] = 0xff;
 758         cmd->scmd.reply_len = sizeof(cmd->pdata);
 759         smu_queue_cmd(&cmd->scmd);
 760 }
 761
 762
 763 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 764 {
 765         struct smu_i2c_cmd      *cmd = misc;
 766         int                     fail = 0;
 767
 768         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 769                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 770
 771         /* Check for possible status */
 772         if (scmd->status < 0)
 773                 fail = 1;
 774         else if (cmd->read) {
 775                 if (cmd->stage == 0)
 776                         fail = cmd->pdata[0] != 0;
 777                 else
 778                         fail = cmd->pdata[0] >= 0x80;
 779         } else {
 780                 fail = cmd->pdata[0] != 0;
 781         }
 782
 783         /* Handle failures by requeuing command, after 5ms interval
 784          */
 785         if (fail && --cmd->retries > 0) {
 786                 DPRINTK("SMU: i2c failure, starting timer...\n");
 787                 BUG_ON(cmd != smu->cmd_i2c_cur);
 788                 if (!smu_irq_inited) {
 789                         mdelay(5);
 790                         smu_i2c_retry(0);
 791                         return;
 792                 }
 793                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 794                 return;
 795         }
 796
 797         /* If failure or stage 1, command is complete */
 798         if (fail || cmd->stage != 0) {
 799                 smu_i2c_complete_command(cmd, fail);
 800                 return;
 801         }
 802
 803         DPRINTK("SMU: going to stage 1\n");
 804
 805         /* Ok, initial command complete, now poll status */
 806         scmd->reply_buf = cmd->pdata;
 807         scmd->reply_len = sizeof(cmd->pdata);
 808         scmd->data_buf = cmd->pdata;
 809         scmd->data_len = 1;
 810         cmd->pdata[0] = 0;
 811         cmd->stage = 1;
 812         cmd->retries = 20;
 813         smu_queue_cmd(scmd);
 814 }
 815
 816
 817 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 818 {
 819         unsigned long flags;
 820
 821         if (smu == NULL)
 822                 return -ENODEV;
 823
 824         /* Fill most fields of scmd */
 825         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 826         cmd->scmd.done = smu_i2c_low_completion;
 827         cmd->scmd.misc = cmd;
 828         cmd->scmd.reply_buf = cmd->pdata;
 829         cmd->scmd.reply_len = sizeof(cmd->pdata);
 830         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 831         cmd->scmd.status = 1;
 832         cmd->stage = 0;
 833         cmd->pdata[0] = 0xff;
 834         cmd->retries = 20;
 835         cmd->status = 1;
 836
 837         /* Check transfer type, sanitize some "info" fields
 838          * based on transfer type and do more checking
 839          */
 840         cmd->info.caddr = cmd->info.devaddr;
 841         cmd->read = cmd->info.devaddr & 0x01;
 842         switch(cmd->info.type) {
 843         case SMU_I2C_TRANSFER_SIMPLE:
 844                 memset(&cmd->info.sublen, 0, 4);
 845                 break;
 846         case SMU_I2C_TRANSFER_COMBINED:
 847                 cmd->info.devaddr &= 0xfe;
 848         case SMU_I2C_TRANSFER_STDSUB:
 849                 if (cmd->info.sublen > 3)
 850                         return -EINVAL;
 851                 break;
 852         default:
 853                 return -EINVAL;
 854         }
 855
 856         /* Finish setting up command based on transfer direction
 857          */
 858         if (cmd->read) {
 859                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 860                         return -EINVAL;
 861                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 862                 cmd->scmd.data_len = 9;
 863         } else {
 864                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 865                         return -EINVAL;
 866                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 867         }
 868
 869         DPRINTK("SMU: i2c enqueuing command\n");
 870         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 871                 cmd->read ? "read" : "write", cmd->info.datalen,
 872                 cmd->info.bus, cmd->info.caddr,
 873                 cmd->info.subaddr[0], cmd->info.type);
 874
 875
 876         /* Enqueue command in i2c list, and if empty, enqueue also in
 877          * main command list
 878          */
 879         spin_lock_irqsave(&smu->lock, flags);
 880         if (smu->cmd_i2c_cur == NULL) {
 881                 smu->cmd_i2c_cur = cmd;
 882                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 883                 if (smu->cmd_cur == NULL)
 884                         smu_start_cmd();
 885         } else
 886                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 887         spin_unlock_irqrestore(&smu->lock, flags);
 888
 889         return 0;
 890 }
 891
 892 /*
 893  * Handling of "partitions"
 894  */
 895
 896 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 897 {
 898         DECLARE_COMPLETION_ONSTACK(comp);
 899         unsigned int chunk;
 900         struct smu_cmd cmd;
 901         int rc;
 902         u8 params[8];
 903
 904         /* We currently use a chunk size of 0xe. We could check the
 905          * SMU firmware version and use bigger sizes though
 906          */
 907         chunk = 0xe;
 908
 909         while (len) {
 910                 unsigned int clen = min(len, chunk);
 911
 912                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 913                 cmd.data_len = 7;
 914                 cmd.data_buf = params;
 915                 cmd.reply_len = chunk;
 916                 cmd.reply_buf = dest;
 917                 cmd.done = smu_done_complete;
 918                 cmd.misc = &comp;
 919                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 920                 params[1] = 0x4;
 921                 *((u32 *)&params[2]) = addr;
 922                 params[6] = clen;
 923
 924                 rc = smu_queue_cmd(&cmd);
 925                 if (rc)
 926                         return rc;
 927                 wait_for_completion(&comp);
 928                 if (cmd.status != 0)
 929                         return rc;
 930                 if (cmd.reply_len != clen) {
 931                         printk(KERN_DEBUG "SMU: short read in "
 932                                "smu_read_datablock, got: %d, want: %d\n",
 933                                cmd.reply_len, clen);
 934                         return -EIO;
 935                 }
 936                 len -= clen;
 937                 addr += clen;
 938                 dest += clen;
 939         }
 940         return 0;
 941 }
 942
 943 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 944 {
 945         DECLARE_COMPLETION_ONSTACK(comp);
 946         struct smu_simple_cmd cmd;
 947         unsigned int addr, len, tlen;
 948         struct smu_sdbp_header *hdr;
 949         struct property *prop;
 950
 951         /* First query the partition info */
 952         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 953         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 954                          smu_done_complete, &comp,
 955                          SMU_CMD_PARTITION_LATEST, id);
 956         wait_for_completion(&comp);
 957         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 958                 cmd.cmd.status, cmd.cmd.reply_len);
 959
 960         /* Partition doesn't exist (or other error) */
 961         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 962                 return NULL;
 963
 964         /* Fetch address and length from reply */
 965         addr = *((u16 *)cmd.buffer);
 966         len = cmd.buffer[3] << 2;
 967         /* Calucluate total length to allocate, including the 17 bytes
 968          * for "sdb-partition-XX" that we append at the end of the buffer
 969          */
 970         tlen = sizeof(struct property) + len + 18;
 971
 972         prop = kzalloc(tlen, GFP_KERNEL);
 973         if (prop == NULL)
 974                 return NULL;
 975         hdr = (struct smu_sdbp_header *)(prop + 1);
 976         prop->name = ((char *)prop) + tlen - 18;
 977         sprintf(prop->name, "sdb-partition-%02x", id);
 978         prop->length = len;
 979         prop->value = hdr;
 980         prop->next = NULL;
 981
 982         /* Read the datablock */
 983         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 984                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 985                        "partition %02x !\n", id);
 986                 goto failure;
 987         }
 988
 989         /* Got it, check a few things and create the property */
 990         if (hdr->id != id) {
 991                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 992                        "%02x !\n", id, hdr->id);
 993                 goto failure;
 994         }
 995         if (of_add_property(smu->of_node, prop)) {
 996                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 997                        "property !\n", id);
 998                 goto failure;
 999         }
1000
1001         return hdr;
1002  failure:
1003         kfree(prop);
1004         return NULL;
1005 }
1006
1007 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1008  * when interruptible is 1
1009  */
1010 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1011                 unsigned int *size, int interruptible)
1012 {
1013         char pname[32];
1014         const struct smu_sdbp_header *part;
1015
1016         if (!smu)
1017                 return NULL;
1018
1019         sprintf(pname, "sdb-partition-%02x", id);
1020
1021         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1022
1023         if (interruptible) {
1024                 int rc;
1025                 rc = mutex_lock_interruptible(&smu_part_access);
1026                 if (rc)
1027                         return ERR_PTR(rc);
1028         } else
1029                 mutex_lock(&smu_part_access);
1030
1031         part = of_get_property(smu->of_node, pname, size);
1032         if (part == NULL) {
1033                 DPRINTK("trying to extract from SMU ...\n");
1034                 part = smu_create_sdb_partition(id);
1035                 if (part != NULL && size)
1036                         *size = part->len << 2;
1037         }
1038         mutex_unlock(&smu_part_access);
1039         return part;
1040 }
1041
1042 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1043 {
1044         return __smu_get_sdb_partition(id, size, 0);
1045 }
1046 EXPORT_SYMBOL(smu_get_sdb_partition);
1047
1048
1049 /*
1050  * Userland driver interface
1051  */
1052
1053
1054 static LIST_HEAD(smu_clist);
1055 static DEFINE_SPINLOCK(smu_clist_lock);
1056
1057 enum smu_file_mode {
1058         smu_file_commands,
1059         smu_file_events,
1060         smu_file_closing
1061 };
1062
1063 struct smu_private
1064 {
1065         struct list_head        list;
1066         enum smu_file_mode      mode;
1067         int                     busy;
1068         struct smu_cmd          cmd;
1069         spinlock_t              lock;
1070         wait_queue_head_t       wait;
1071         u8                      buffer[SMU_MAX_DATA];
1072 };
1073
1074
1075 static int smu_open(struct inode *inode, struct file *file)
1076 {
1077         struct smu_private *pp;
1078         unsigned long flags;
1079
1080         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1081         if (pp == 0)
1082                 return -ENOMEM;
1083         spin_lock_init(&pp->lock);
1084         pp->mode = smu_file_commands;
1085         init_waitqueue_head(&pp->wait);
1086
1087         mutex_lock(&smu_mutex);
1088         spin_lock_irqsave(&smu_clist_lock, flags);
1089         list_add(&pp->list, &smu_clist);
1090         spin_unlock_irqrestore(&smu_clist_lock, flags);
1091         file->private_data = pp;
1092         mutex_unlock(&smu_mutex);
1093
1094         return 0;
1095 }
1096
1097
1098 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1099 {
1100         struct smu_private *pp = misc;
1101
1102         wake_up_all(&pp->wait);
1103 }
1104
1105
1106 static ssize_t smu_write(struct file *file, const char __user *buf,
1107                          size_t count, loff_t *ppos)
1108 {
1109         struct smu_private *pp = file->private_data;
1110         unsigned long flags;
1111         struct smu_user_cmd_hdr hdr;
1112         int rc = 0;
1113
1114         if (pp->busy)
1115                 return -EBUSY;
1116         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1117                 return -EFAULT;
1118         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1119                 pp->mode = smu_file_events;
1120                 return 0;
1121         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1122                 const struct smu_sdbp_header *part;
1123                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1124                 if (part == NULL)
1125                         return -EINVAL;
1126                 else if (IS_ERR(part))
1127                         return PTR_ERR(part);
1128                 return 0;
1129         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1130                 return -EINVAL;
1131         else if (pp->mode != smu_file_commands)
1132                 return -EBADFD;
1133         else if (hdr.data_len > SMU_MAX_DATA)
1134                 return -EINVAL;
1135
1136         spin_lock_irqsave(&pp->lock, flags);
1137         if (pp->busy) {
1138                 spin_unlock_irqrestore(&pp->lock, flags);
1139                 return -EBUSY;
1140         }
1141         pp->busy = 1;
1142         pp->cmd.status = 1;
1143         spin_unlock_irqrestore(&pp->lock, flags);
1144
1145         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1146                 pp->busy = 0;
1147                 return -EFAULT;
1148         }
1149
1150         pp->cmd.cmd = hdr.cmd;
1151         pp->cmd.data_len = hdr.data_len;
1152         pp->cmd.reply_len = SMU_MAX_DATA;
1153         pp->cmd.data_buf = pp->buffer;
1154         pp->cmd.reply_buf = pp->buffer;
1155         pp->cmd.done = smu_user_cmd_done;
1156         pp->cmd.misc = pp;
1157         rc = smu_queue_cmd(&pp->cmd);
1158         if (rc < 0)
1159                 return rc;
1160         return count;
1161 }
1162
1163
1164 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1165                                 char __user *buf, size_t count)
1166 {
1167         DECLARE_WAITQUEUE(wait, current);
1168         struct smu_user_reply_hdr hdr;
1169         unsigned long flags;
1170         int size, rc = 0;
1171
1172         if (!pp->busy)
1173                 return 0;
1174         if (count < sizeof(struct smu_user_reply_hdr))
1175                 return -EOVERFLOW;
1176         spin_lock_irqsave(&pp->lock, flags);
1177         if (pp->cmd.status == 1) {
1178                 if (file->f_flags & O_NONBLOCK) {
1179                         spin_unlock_irqrestore(&pp->lock, flags);
1180                         return -EAGAIN;
1181                 }
1182                 add_wait_queue(&pp->wait, &wait);
1183                 for (;;) {
1184                         set_current_state(TASK_INTERRUPTIBLE);
1185                         rc = 0;
1186                         if (pp->cmd.status != 1)
1187                                 break;
1188                         rc = -ERESTARTSYS;
1189                         if (signal_pending(current))
1190                                 break;
1191                         spin_unlock_irqrestore(&pp->lock, flags);
1192                         schedule();
1193                         spin_lock_irqsave(&pp->lock, flags);
1194                 }
1195                 set_current_state(TASK_RUNNING);
1196                 remove_wait_queue(&pp->wait, &wait);
1197         }
1198         spin_unlock_irqrestore(&pp->lock, flags);
1199         if (rc)
1200                 return rc;
1201         if (pp->cmd.status != 0)
1202                 pp->cmd.reply_len = 0;
1203         size = sizeof(hdr) + pp->cmd.reply_len;
1204         if (count < size)
1205                 size = count;
1206         rc = size;
1207         hdr.status = pp->cmd.status;
1208         hdr.reply_len = pp->cmd.reply_len;
1209         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1210                 return -EFAULT;
1211         size -= sizeof(hdr);
1212         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1213                 return -EFAULT;
1214         pp->busy = 0;
1215
1216         return rc;
1217 }
1218
1219
1220 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1221                                char __user *buf, size_t count)
1222 {
1223         /* Not implemented */
1224         msleep_interruptible(1000);
1225         return 0;
1226 }
1227
1228
1229 static ssize_t smu_read(struct file *file, char __user *buf,
1230                         size_t count, loff_t *ppos)
1231 {
1232         struct smu_private *pp = file->private_data;
1233
1234         if (pp->mode == smu_file_commands)
1235                 return smu_read_command(file, pp, buf, count);
1236         if (pp->mode == smu_file_events)
1237                 return smu_read_events(file, pp, buf, count);
1238
1239         return -EBADFD;
1240 }
1241
1242 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1243 {
1244         struct smu_private *pp = file->private_data;
1245         unsigned int mask = 0;
1246         unsigned long flags;
1247
1248         if (pp == 0)
1249                 return 0;
1250
1251         if (pp->mode == smu_file_commands) {
1252                 poll_wait(file, &pp->wait, wait);
1253
1254                 spin_lock_irqsave(&pp->lock, flags);
1255                 if (pp->busy && pp->cmd.status != 1)
1256                         mask |= POLLIN;
1257                 spin_unlock_irqrestore(&pp->lock, flags);
1258         }
1259         if (pp->mode == smu_file_events) {
1260                 /* Not yet implemented */
1261         }
1262         return mask;
1263 }
1264
1265 static int smu_release(struct inode *inode, struct file *file)
1266 {
1267         struct smu_private *pp = file->private_data;
1268         unsigned long flags;
1269         unsigned int busy;
1270
1271         if (pp == 0)
1272                 return 0;
1273
1274         file->private_data = NULL;
1275
1276         /* Mark file as closing to avoid races with new request */
1277         spin_lock_irqsave(&pp->lock, flags);
1278         pp->mode = smu_file_closing;
1279         busy = pp->busy;
1280
1281         /* Wait for any pending request to complete */
1282         if (busy && pp->cmd.status == 1) {
1283                 DECLARE_WAITQUEUE(wait, current);
1284
1285                 add_wait_queue(&pp->wait, &wait);
1286                 for (;;) {
1287                         set_current_state(TASK_UNINTERRUPTIBLE);
1288                         if (pp->cmd.status != 1)
1289                                 break;
1290                         spin_unlock_irqrestore(&pp->lock, flags);
1291                         schedule();
1292                         spin_lock_irqsave(&pp->lock, flags);
1293                 }
1294                 set_current_state(TASK_RUNNING);
1295                 remove_wait_queue(&pp->wait, &wait);
1296         }
1297         spin_unlock_irqrestore(&pp->lock, flags);
1298
1299         spin_lock_irqsave(&smu_clist_lock, flags);
1300         list_del(&pp->list);
1301         spin_unlock_irqrestore(&smu_clist_lock, flags);
1302         kfree(pp);
1303
1304         return 0;
1305 }
1306
1307
1308 static const struct file_operations smu_device_fops = {
1309         .llseek         = no_llseek,
1310         .read           = smu_read,
1311         .write          = smu_write,
1312         .poll           = smu_fpoll,
1313         .open           = smu_open,
1314         .release        = smu_release,
1315 };
1316
1317 static struct miscdevice pmu_device = {
1318         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1319 };
1320
1321 static int smu_device_init(void)
1322 {
1323         if (!smu)
1324                 return -ENODEV;
1325         if (misc_register(&pmu_device) < 0)
1326                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1327         return 0;
1328 }
1329 device_initcall(smu_device_init);