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/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         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 struct smu_device        *smu;
  99 static DEFINE_MUTEX(smu_part_access);
 100 static int smu_irq_inited;
 101
 102 static void smu_i2c_retry(unsigned long data);
 103
 104 /*
 105  * SMU driver low level stuff
 106  */
 107
 108 static void smu_start_cmd(void)
 109 {
 110         unsigned long faddr, fend;
 111         struct smu_cmd *cmd;
 112
 113         if (list_empty(&smu->cmd_list))
 114                 return;
 115
 116         /* Fetch first command in queue */
 117         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 118         smu->cmd_cur = cmd;
 119         list_del(&cmd->link);
 120
 121         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 122                 cmd->data_len);
 123         DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 124                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 125                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 126                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 127                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 128
 129         /* Fill the SMU command buffer */
 130         smu->cmd_buf->cmd = cmd->cmd;
 131         smu->cmd_buf->length = cmd->data_len;
 132         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 133
 134         /* Flush command and data to RAM */
 135         faddr = (unsigned long)smu->cmd_buf;
 136         fend = faddr + smu->cmd_buf->length + 2;
 137         flush_inval_dcache_range(faddr, fend);
 138
 139
 140         /* We also disable NAP mode for the duration of the command
 141          * on U3 based machines.
 142          * This is slightly racy as it can be written back to 1 by a sysctl
 143          * but that never happens in practice. There seem to be an issue with
 144          * U3 based machines such as the iMac G5 where napping for the
 145          * whole duration of the command prevents the SMU from fetching it
 146          * from memory. This might be related to the strange i2c based
 147          * mechanism the SMU uses to access memory.
 148          */
 149         if (smu->broken_nap)
 150                 powersave_nap = 0;
 151
 152         /* This isn't exactly a DMA mapping here, I suspect
 153          * the SMU is actually communicating with us via i2c to the
 154          * northbridge or the CPU to access RAM.
 155          */
 156         writel(smu->cmd_buf_abs, smu->db_buf);
 157
 158         /* Ring the SMU doorbell */
 159         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 160 }
 161
 162
 163 static irqreturn_t smu_db_intr(int irq, void *arg)
 164 {
 165         unsigned long flags;
 166         struct smu_cmd *cmd;
 167         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 168         void *misc = NULL;
 169         u8 gpio;
 170         int rc = 0;
 171
 172         /* SMU completed the command, well, we hope, let's make sure
 173          * of it
 174          */
 175         spin_lock_irqsave(&smu->lock, flags);
 176
 177         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 178         if ((gpio & 7) != 7) {
 179                 spin_unlock_irqrestore(&smu->lock, flags);
 180                 return IRQ_HANDLED;
 181         }
 182
 183         cmd = smu->cmd_cur;
 184         smu->cmd_cur = NULL;
 185         if (cmd == NULL)
 186                 goto bail;
 187
 188         if (rc == 0) {
 189                 unsigned long faddr;
 190                 int reply_len;
 191                 u8 ack;
 192
 193                 /* CPU might have brought back the cache line, so we need
 194                  * to flush again before peeking at the SMU response. We
 195                  * flush the entire buffer for now as we haven't read the
 196                  * reply length (it's only 2 cache lines anyway)
 197                  */
 198                 faddr = (unsigned long)smu->cmd_buf;
 199                 flush_inval_dcache_range(faddr, faddr + 256);
 200
 201                 /* Now check ack */
 202                 ack = (~cmd->cmd) & 0xff;
 203                 if (ack != smu->cmd_buf->cmd) {
 204                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 205                                 ack, smu->cmd_buf->cmd);
 206                         rc = -EIO;
 207                 }
 208                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 209                 DPRINTK("SMU: reply len: %d\n", reply_len);
 210                 if (reply_len > cmd->reply_len) {
 211                         printk(KERN_WARNING "SMU: reply buffer too small,"
 212                                "got %d bytes for a %d bytes buffer\n",
 213                                reply_len, cmd->reply_len);
 214                         reply_len = cmd->reply_len;
 215                 }
 216                 cmd->reply_len = reply_len;
 217                 if (cmd->reply_buf && reply_len)
 218                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 219         }
 220
 221         /* Now complete the command. Write status last in order as we lost
 222          * ownership of the command structure as soon as it's no longer -1
 223          */
 224         done = cmd->done;
 225         misc = cmd->misc;
 226         mb();
 227         cmd->status = rc;
 228
 229         /* Re-enable NAP mode */
 230         if (smu->broken_nap)
 231                 powersave_nap = 1;
 232  bail:
 233         /* Start next command if any */
 234         smu_start_cmd();
 235         spin_unlock_irqrestore(&smu->lock, flags);
 236
 237         /* Call command completion handler if any */
 238         if (done)
 239                 done(cmd, misc);
 240
 241         /* It's an edge interrupt, nothing to do */
 242         return IRQ_HANDLED;
 243 }
 244
 245
 246 static irqreturn_t smu_msg_intr(int irq, void *arg)
 247 {
 248         /* I don't quite know what to do with this one, we seem to never
 249          * receive it, so I suspect we have to arm it someway in the SMU
 250          * to start getting events that way.
 251          */
 252
 253         printk(KERN_INFO "SMU: message interrupt !\n");
 254
 255         /* It's an edge interrupt, nothing to do */
 256         return IRQ_HANDLED;
 257 }
 258
 259
 260 /*
 261  * Queued command management.
 262  *
 263  */
 264
 265 int smu_queue_cmd(struct smu_cmd *cmd)
 266 {
 267         unsigned long flags;
 268
 269         if (smu == NULL)
 270                 return -ENODEV;
 271         if (cmd->data_len > SMU_MAX_DATA ||
 272             cmd->reply_len > SMU_MAX_DATA)
 273                 return -EINVAL;
 274
 275         cmd->status = 1;
 276         spin_lock_irqsave(&smu->lock, flags);
 277         list_add_tail(&cmd->link, &smu->cmd_list);
 278         if (smu->cmd_cur == NULL)
 279                 smu_start_cmd();
 280         spin_unlock_irqrestore(&smu->lock, flags);
 281
 282         /* Workaround for early calls when irq isn't available */
 283         if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 284                 smu_spinwait_cmd(cmd);
 285
 286         return 0;
 287 }
 288 EXPORT_SYMBOL(smu_queue_cmd);
 289
 290
 291 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 292                      unsigned int data_len,
 293                      void (*done)(struct smu_cmd *cmd, void *misc),
 294                      void *misc, ...)
 295 {
 296         struct smu_cmd *cmd = &scmd->cmd;
 297         va_list list;
 298         int i;
 299
 300         if (data_len > sizeof(scmd->buffer))
 301                 return -EINVAL;
 302
 303         memset(scmd, 0, sizeof(*scmd));
 304         cmd->cmd = command;
 305         cmd->data_len = data_len;
 306         cmd->data_buf = scmd->buffer;
 307         cmd->reply_len = sizeof(scmd->buffer);
 308         cmd->reply_buf = scmd->buffer;
 309         cmd->done = done;
 310         cmd->misc = misc;
 311
 312         va_start(list, misc);
 313         for (i = 0; i < data_len; ++i)
 314                 scmd->buffer[i] = (u8)va_arg(list, int);
 315         va_end(list);
 316
 317         return smu_queue_cmd(cmd);
 318 }
 319 EXPORT_SYMBOL(smu_queue_simple);
 320
 321
 322 void smu_poll(void)
 323 {
 324         u8 gpio;
 325
 326         if (smu == NULL)
 327                 return;
 328
 329         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 330         if ((gpio & 7) == 7)
 331                 smu_db_intr(smu->db_irq, smu);
 332 }
 333 EXPORT_SYMBOL(smu_poll);
 334
 335
 336 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 337 {
 338         struct completion *comp = misc;
 339
 340         complete(comp);
 341 }
 342 EXPORT_SYMBOL(smu_done_complete);
 343
 344
 345 void smu_spinwait_cmd(struct smu_cmd *cmd)
 346 {
 347         while(cmd->status == 1)
 348                 smu_poll();
 349 }
 350 EXPORT_SYMBOL(smu_spinwait_cmd);
 351
 352
 353 /* RTC low level commands */
 354 static inline int bcd2hex (int n)
 355 {
 356         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 357 }
 358
 359
 360 static inline int hex2bcd (int n)
 361 {
 362         return ((n / 10) << 4) + (n % 10);
 363 }
 364
 365
 366 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 367                                         struct rtc_time *time)
 368 {
 369         cmd_buf->cmd = 0x8e;
 370         cmd_buf->length = 8;
 371         cmd_buf->data[0] = 0x80;
 372         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 373         cmd_buf->data[2] = hex2bcd(time->tm_min);
 374         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 375         cmd_buf->data[4] = time->tm_wday;
 376         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 377         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 378         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 379 }
 380
 381
 382 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 383 {
 384         struct smu_simple_cmd cmd;
 385         int rc;
 386
 387         if (smu == NULL)
 388                 return -ENODEV;
 389
 390         memset(time, 0, sizeof(struct rtc_time));
 391         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 392                               SMU_CMD_RTC_GET_DATETIME);
 393         if (rc)
 394                 return rc;
 395         smu_spinwait_simple(&cmd);
 396
 397         time->tm_sec = bcd2hex(cmd.buffer[0]);
 398         time->tm_min = bcd2hex(cmd.buffer[1]);
 399         time->tm_hour = bcd2hex(cmd.buffer[2]);
 400         time->tm_wday = bcd2hex(cmd.buffer[3]);
 401         time->tm_mday = bcd2hex(cmd.buffer[4]);
 402         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 403         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 404
 405         return 0;
 406 }
 407
 408
 409 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 410 {
 411         struct smu_simple_cmd cmd;
 412         int rc;
 413
 414         if (smu == NULL)
 415                 return -ENODEV;
 416
 417         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 418                               SMU_CMD_RTC_SET_DATETIME,
 419                               hex2bcd(time->tm_sec),
 420                               hex2bcd(time->tm_min),
 421                               hex2bcd(time->tm_hour),
 422                               time->tm_wday,
 423                               hex2bcd(time->tm_mday),
 424                               hex2bcd(time->tm_mon) + 1,
 425                               hex2bcd(time->tm_year - 100));
 426         if (rc)
 427                 return rc;
 428         smu_spinwait_simple(&cmd);
 429
 430         return 0;
 431 }
 432
 433
 434 void smu_shutdown(void)
 435 {
 436         struct smu_simple_cmd cmd;
 437
 438         if (smu == NULL)
 439                 return;
 440
 441         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 442                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 443                 return;
 444         smu_spinwait_simple(&cmd);
 445         for (;;)
 446                 ;
 447 }
 448
 449
 450 void smu_restart(void)
 451 {
 452         struct smu_simple_cmd cmd;
 453
 454         if (smu == NULL)
 455                 return;
 456
 457         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 458                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 459                 return;
 460         smu_spinwait_simple(&cmd);
 461         for (;;)
 462                 ;
 463 }
 464
 465
 466 int smu_present(void)
 467 {
 468         return smu != NULL;
 469 }
 470 EXPORT_SYMBOL(smu_present);
 471
 472
 473 int __init smu_init (void)
 474 {
 475         struct device_node *np;
 476         const u32 *data;
 477
 478         np = of_find_node_by_type(NULL, "smu");
 479         if (np == NULL)
 480                 return -ENODEV;
 481
 482         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 483
 484         if (smu_cmdbuf_abs == 0) {
 485                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 486                 return -EINVAL;
 487         }
 488
 489         smu = alloc_bootmem(sizeof(struct smu_device));
 490         if (smu == NULL)
 491                 return -ENOMEM;
 492         memset(smu, 0, sizeof(*smu));
 493
 494         spin_lock_init(&smu->lock);
 495         INIT_LIST_HEAD(&smu->cmd_list);
 496         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 497         smu->of_node = np;
 498         smu->db_irq = NO_IRQ;
 499         smu->msg_irq = NO_IRQ;
 500
 501         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 502          * 32 bits value safely
 503          */
 504         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 505         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 506
 507         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 508         if (smu->db_node == NULL) {
 509                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 510                 goto fail;
 511         }
 512         data = of_get_property(smu->db_node, "reg", NULL);
 513         if (data == NULL) {
 514                 of_node_put(smu->db_node);
 515                 smu->db_node = NULL;
 516                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 517                 goto fail;
 518         }
 519
 520         /* Current setup has one doorbell GPIO that does both doorbell
 521          * and ack. GPIOs are at 0x50, best would be to find that out
 522          * in the device-tree though.
 523          */
 524         smu->doorbell = *data;
 525         if (smu->doorbell < 0x50)
 526                 smu->doorbell += 0x50;
 527
 528         /* Now look for the smu-interrupt GPIO */
 529         do {
 530                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 531                 if (smu->msg_node == NULL)
 532                         break;
 533                 data = of_get_property(smu->msg_node, "reg", NULL);
 534                 if (data == NULL) {
 535                         of_node_put(smu->msg_node);
 536                         smu->msg_node = NULL;
 537                         break;
 538                 }
 539                 smu->msg = *data;
 540                 if (smu->msg < 0x50)
 541                         smu->msg += 0x50;
 542         } while(0);
 543
 544         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 545          * device-tree entry giving the address. Best would probably to use
 546          * an offset for K2 base though, but let's do it that way for now.
 547          */
 548         smu->db_buf = ioremap(0x8000860c, 0x1000);
 549         if (smu->db_buf == NULL) {
 550                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 551                 goto fail;
 552         }
 553
 554         /* U3 has an issue with NAP mode when issuing SMU commands */
 555         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 556         if (smu->broken_nap)
 557                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 558
 559         sys_ctrler = SYS_CTRLER_SMU;
 560         return 0;
 561
 562  fail:
 563         smu = NULL;
 564         return -ENXIO;
 565
 566 }
 567
 568
 569 static int smu_late_init(void)
 570 {
 571         if (!smu)
 572                 return 0;
 573
 574         init_timer(&smu->i2c_timer);
 575         smu->i2c_timer.function = smu_i2c_retry;
 576         smu->i2c_timer.data = (unsigned long)smu;
 577
 578         if (smu->db_node) {
 579                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 580                 if (smu->db_irq == NO_IRQ)
 581                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 582                                smu->db_node->full_name);
 583         }
 584         if (smu->msg_node) {
 585                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 586                 if (smu->msg_irq == NO_IRQ)
 587                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 588                                smu->msg_node->full_name);
 589         }
 590
 591         /*
 592          * Try to request the interrupts
 593          */
 594
 595         if (smu->db_irq != NO_IRQ) {
 596                 if (request_irq(smu->db_irq, smu_db_intr,
 597                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 598                         printk(KERN_WARNING "SMU: can't "
 599                                "request interrupt %d\n",
 600                                smu->db_irq);
 601                         smu->db_irq = NO_IRQ;
 602                 }
 603         }
 604
 605         if (smu->msg_irq != NO_IRQ) {
 606                 if (request_irq(smu->msg_irq, smu_msg_intr,
 607                                 IRQF_SHARED, "SMU message", smu) < 0) {
 608                         printk(KERN_WARNING "SMU: can't "
 609                                "request interrupt %d\n",
 610                                smu->msg_irq);
 611                         smu->msg_irq = NO_IRQ;
 612                 }
 613         }
 614
 615         smu_irq_inited = 1;
 616         return 0;
 617 }
 618 /* This has to be before arch_initcall as the low i2c stuff relies on the
 619  * above having been done before we reach arch_initcalls
 620  */
 621 core_initcall(smu_late_init);
 622
 623 /*
 624  * sysfs visibility
 625  */
 626
 627 static void smu_expose_childs(struct work_struct *unused)
 628 {
 629         struct device_node *np;
 630
 631         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 632                 if (of_device_is_compatible(np, "smu-sensors"))
 633                         of_platform_device_create(np, "smu-sensors",
 634                                                   &smu->of_dev->dev);
 635 }
 636
 637 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 638
 639 static int smu_platform_probe(struct of_device* dev,
 640                               const struct of_device_id *match)
 641 {
 642         if (!smu)
 643                 return -ENODEV;
 644         smu->of_dev = dev;
 645
 646         /*
 647          * Ok, we are matched, now expose all i2c busses. We have to defer
 648          * that unfortunately or it would deadlock inside the device model
 649          */
 650         schedule_work(&smu_expose_childs_work);
 651
 652         return 0;
 653 }
 654
 655 static struct of_device_id smu_platform_match[] =
 656 {
 657         {
 658                 .type           = "smu",
 659         },
 660         {},
 661 };
 662
 663 static struct of_platform_driver smu_of_platform_driver =
 664 {
 665         .name           = "smu",
 666         .match_table    = smu_platform_match,
 667         .probe          = smu_platform_probe,
 668 };
 669
 670 static int __init smu_init_sysfs(void)
 671 {
 672         /*
 673          * Due to sysfs bogosity, a sysdev is not a real device, so
 674          * we should in fact create both if we want sysdev semantics
 675          * for power management.
 676          * For now, we don't power manage machines with an SMU chip,
 677          * I'm a bit too far from figuring out how that works with those
 678          * new chipsets, but that will come back and bite us
 679          */
 680         of_register_platform_driver(&smu_of_platform_driver);
 681         return 0;
 682 }
 683
 684 device_initcall(smu_init_sysfs);
 685
 686 struct of_device *smu_get_ofdev(void)
 687 {
 688         if (!smu)
 689                 return NULL;
 690         return smu->of_dev;
 691 }
 692
 693 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 694
 695 /*
 696  * i2c interface
 697  */
 698
 699 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 700 {
 701         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 702         void *misc = cmd->misc;
 703         unsigned long flags;
 704
 705         /* Check for read case */
 706         if (!fail && cmd->read) {
 707                 if (cmd->pdata[0] < 1)
 708                         fail = 1;
 709                 else
 710                         memcpy(cmd->info.data, &cmd->pdata[1],
 711                                cmd->info.datalen);
 712         }
 713
 714         DPRINTK("SMU: completing, success: %d\n", !fail);
 715
 716         /* Update status and mark no pending i2c command with lock
 717          * held so nobody comes in while we dequeue an eventual
 718          * pending next i2c command
 719          */
 720         spin_lock_irqsave(&smu->lock, flags);
 721         smu->cmd_i2c_cur = NULL;
 722         wmb();
 723         cmd->status = fail ? -EIO : 0;
 724
 725         /* Is there another i2c command waiting ? */
 726         if (!list_empty(&smu->cmd_i2c_list)) {
 727                 struct smu_i2c_cmd *newcmd;
 728
 729                 /* Fetch it, new current, remove from list */
 730                 newcmd = list_entry(smu->cmd_i2c_list.next,
 731                                     struct smu_i2c_cmd, link);
 732                 smu->cmd_i2c_cur = newcmd;
 733                 list_del(&cmd->link);
 734
 735                 /* Queue with low level smu */
 736                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 737                 if (smu->cmd_cur == NULL)
 738                         smu_start_cmd();
 739         }
 740         spin_unlock_irqrestore(&smu->lock, flags);
 741
 742         /* Call command completion handler if any */
 743         if (done)
 744                 done(cmd, misc);
 745
 746 }
 747
 748
 749 static void smu_i2c_retry(unsigned long data)
 750 {
 751         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 752
 753         DPRINTK("SMU: i2c failure, requeuing...\n");
 754
 755         /* requeue command simply by resetting reply_len */
 756         cmd->pdata[0] = 0xff;
 757         cmd->scmd.reply_len = sizeof(cmd->pdata);
 758         smu_queue_cmd(&cmd->scmd);
 759 }
 760
 761
 762 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 763 {
 764         struct smu_i2c_cmd      *cmd = misc;
 765         int                     fail = 0;
 766
 767         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 768                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 769
 770         /* Check for possible status */
 771         if (scmd->status < 0)
 772                 fail = 1;
 773         else if (cmd->read) {
 774                 if (cmd->stage == 0)
 775                         fail = cmd->pdata[0] != 0;
 776                 else
 777                         fail = cmd->pdata[0] >= 0x80;
 778         } else {
 779                 fail = cmd->pdata[0] != 0;
 780         }
 781
 782         /* Handle failures by requeuing command, after 5ms interval
 783          */
 784         if (fail && --cmd->retries > 0) {
 785                 DPRINTK("SMU: i2c failure, starting timer...\n");
 786                 BUG_ON(cmd != smu->cmd_i2c_cur);
 787                 if (!smu_irq_inited) {
 788                         mdelay(5);
 789                         smu_i2c_retry(0);
 790                         return;
 791                 }
 792                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 793                 return;
 794         }
 795
 796         /* If failure or stage 1, command is complete */
 797         if (fail || cmd->stage != 0) {
 798                 smu_i2c_complete_command(cmd, fail);
 799                 return;
 800         }
 801
 802         DPRINTK("SMU: going to stage 1\n");
 803
 804         /* Ok, initial command complete, now poll status */
 805         scmd->reply_buf = cmd->pdata;
 806         scmd->reply_len = sizeof(cmd->pdata);
 807         scmd->data_buf = cmd->pdata;
 808         scmd->data_len = 1;
 809         cmd->pdata[0] = 0;
 810         cmd->stage = 1;
 811         cmd->retries = 20;
 812         smu_queue_cmd(scmd);
 813 }
 814
 815
 816 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 817 {
 818         unsigned long flags;
 819
 820         if (smu == NULL)
 821                 return -ENODEV;
 822
 823         /* Fill most fields of scmd */
 824         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 825         cmd->scmd.done = smu_i2c_low_completion;
 826         cmd->scmd.misc = cmd;
 827         cmd->scmd.reply_buf = cmd->pdata;
 828         cmd->scmd.reply_len = sizeof(cmd->pdata);
 829         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 830         cmd->scmd.status = 1;
 831         cmd->stage = 0;
 832         cmd->pdata[0] = 0xff;
 833         cmd->retries = 20;
 834         cmd->status = 1;
 835
 836         /* Check transfer type, sanitize some "info" fields
 837          * based on transfer type and do more checking
 838          */
 839         cmd->info.caddr = cmd->info.devaddr;
 840         cmd->read = cmd->info.devaddr & 0x01;
 841         switch(cmd->info.type) {
 842         case SMU_I2C_TRANSFER_SIMPLE:
 843                 memset(&cmd->info.sublen, 0, 4);
 844                 break;
 845         case SMU_I2C_TRANSFER_COMBINED:
 846                 cmd->info.devaddr &= 0xfe;
 847         case SMU_I2C_TRANSFER_STDSUB:
 848                 if (cmd->info.sublen > 3)
 849                         return -EINVAL;
 850                 break;
 851         default:
 852                 return -EINVAL;
 853         }
 854
 855         /* Finish setting up command based on transfer direction
 856          */
 857         if (cmd->read) {
 858                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 859                         return -EINVAL;
 860                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 861                 cmd->scmd.data_len = 9;
 862         } else {
 863                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 864                         return -EINVAL;
 865                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 866         }
 867
 868         DPRINTK("SMU: i2c enqueuing command\n");
 869         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 870                 cmd->read ? "read" : "write", cmd->info.datalen,
 871                 cmd->info.bus, cmd->info.caddr,
 872                 cmd->info.subaddr[0], cmd->info.type);
 873
 874
 875         /* Enqueue command in i2c list, and if empty, enqueue also in
 876          * main command list
 877          */
 878         spin_lock_irqsave(&smu->lock, flags);
 879         if (smu->cmd_i2c_cur == NULL) {
 880                 smu->cmd_i2c_cur = cmd;
 881                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 882                 if (smu->cmd_cur == NULL)
 883                         smu_start_cmd();
 884         } else
 885                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 886         spin_unlock_irqrestore(&smu->lock, flags);
 887
 888         return 0;
 889 }
 890
 891 /*
 892  * Handling of "partitions"
 893  */
 894
 895 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 896 {
 897         DECLARE_COMPLETION_ONSTACK(comp);
 898         unsigned int chunk;
 899         struct smu_cmd cmd;
 900         int rc;
 901         u8 params[8];
 902
 903         /* We currently use a chunk size of 0xe. We could check the
 904          * SMU firmware version and use bigger sizes though
 905          */
 906         chunk = 0xe;
 907
 908         while (len) {
 909                 unsigned int clen = min(len, chunk);
 910
 911                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 912                 cmd.data_len = 7;
 913                 cmd.data_buf = params;
 914                 cmd.reply_len = chunk;
 915                 cmd.reply_buf = dest;
 916                 cmd.done = smu_done_complete;
 917                 cmd.misc = &comp;
 918                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 919                 params[1] = 0x4;
 920                 *((u32 *)&params[2]) = addr;
 921                 params[6] = clen;
 922
 923                 rc = smu_queue_cmd(&cmd);
 924                 if (rc)
 925                         return rc;
 926                 wait_for_completion(&comp);
 927                 if (cmd.status != 0)
 928                         return rc;
 929                 if (cmd.reply_len != clen) {
 930                         printk(KERN_DEBUG "SMU: short read in "
 931                                "smu_read_datablock, got: %d, want: %d\n",
 932                                cmd.reply_len, clen);
 933                         return -EIO;
 934                 }
 935                 len -= clen;
 936                 addr += clen;
 937                 dest += clen;
 938         }
 939         return 0;
 940 }
 941
 942 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 943 {
 944         DECLARE_COMPLETION_ONSTACK(comp);
 945         struct smu_simple_cmd cmd;
 946         unsigned int addr, len, tlen;
 947         struct smu_sdbp_header *hdr;
 948         struct property *prop;
 949
 950         /* First query the partition info */
 951         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 952         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 953                          smu_done_complete, &comp,
 954                          SMU_CMD_PARTITION_LATEST, id);
 955         wait_for_completion(&comp);
 956         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 957                 cmd.cmd.status, cmd.cmd.reply_len);
 958
 959         /* Partition doesn't exist (or other error) */
 960         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 961                 return NULL;
 962
 963         /* Fetch address and length from reply */
 964         addr = *((u16 *)cmd.buffer);
 965         len = cmd.buffer[3] << 2;
 966         /* Calucluate total length to allocate, including the 17 bytes
 967          * for "sdb-partition-XX" that we append at the end of the buffer
 968          */
 969         tlen = sizeof(struct property) + len + 18;
 970
 971         prop = kzalloc(tlen, GFP_KERNEL);
 972         if (prop == NULL)
 973                 return NULL;
 974         hdr = (struct smu_sdbp_header *)(prop + 1);
 975         prop->name = ((char *)prop) + tlen - 18;
 976         sprintf(prop->name, "sdb-partition-%02x", id);
 977         prop->length = len;
 978         prop->value = hdr;
 979         prop->next = NULL;
 980
 981         /* Read the datablock */
 982         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 983                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 984                        "partition %02x !\n", id);
 985                 goto failure;
 986         }
 987
 988         /* Got it, check a few things and create the property */
 989         if (hdr->id != id) {
 990                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 991                        "%02x !\n", id, hdr->id);
 992                 goto failure;
 993         }
 994         if (prom_add_property(smu->of_node, prop)) {
 995                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 996                        "property !\n", id);
 997                 goto failure;
 998         }
 999
1000         return hdr;
1001  failure:
1002         kfree(prop);
1003         return NULL;
1004 }
1005
1006 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1007  * when interruptible is 1
1008  */
1009 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1010                 unsigned int *size, int interruptible)
1011 {
1012         char pname[32];
1013         const struct smu_sdbp_header *part;
1014
1015         if (!smu)
1016                 return NULL;
1017
1018         sprintf(pname, "sdb-partition-%02x", id);
1019
1020         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1021
1022         if (interruptible) {
1023                 int rc;
1024                 rc = mutex_lock_interruptible(&smu_part_access);
1025                 if (rc)
1026                         return ERR_PTR(rc);
1027         } else
1028                 mutex_lock(&smu_part_access);
1029
1030         part = of_get_property(smu->of_node, pname, size);
1031         if (part == NULL) {
1032                 DPRINTK("trying to extract from SMU ...\n");
1033                 part = smu_create_sdb_partition(id);
1034                 if (part != NULL && size)
1035                         *size = part->len << 2;
1036         }
1037         mutex_unlock(&smu_part_access);
1038         return part;
1039 }
1040
1041 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1042 {
1043         return __smu_get_sdb_partition(id, size, 0);
1044 }
1045 EXPORT_SYMBOL(smu_get_sdb_partition);
1046
1047
1048 /*
1049  * Userland driver interface
1050  */
1051
1052
1053 static LIST_HEAD(smu_clist);
1054 static DEFINE_SPINLOCK(smu_clist_lock);
1055
1056 enum smu_file_mode {
1057         smu_file_commands,
1058         smu_file_events,
1059         smu_file_closing
1060 };
1061
1062 struct smu_private
1063 {
1064         struct list_head        list;
1065         enum smu_file_mode      mode;
1066         int                     busy;
1067         struct smu_cmd          cmd;
1068         spinlock_t              lock;
1069         wait_queue_head_t       wait;
1070         u8                      buffer[SMU_MAX_DATA];
1071 };
1072
1073
1074 static int smu_open(struct inode *inode, struct file *file)
1075 {
1076         struct smu_private *pp;
1077         unsigned long flags;
1078
1079         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1080         if (pp == 0)
1081                 return -ENOMEM;
1082         spin_lock_init(&pp->lock);
1083         pp->mode = smu_file_commands;
1084         init_waitqueue_head(&pp->wait);
1085
1086         spin_lock_irqsave(&smu_clist_lock, flags);
1087         list_add(&pp->list, &smu_clist);
1088         spin_unlock_irqrestore(&smu_clist_lock, flags);
1089         file->private_data = pp;
1090
1091         return 0;
1092 }
1093
1094
1095 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1096 {
1097         struct smu_private *pp = misc;
1098
1099         wake_up_all(&pp->wait);
1100 }
1101
1102
1103 static ssize_t smu_write(struct file *file, const char __user *buf,
1104                          size_t count, loff_t *ppos)
1105 {
1106         struct smu_private *pp = file->private_data;
1107         unsigned long flags;
1108         struct smu_user_cmd_hdr hdr;
1109         int rc = 0;
1110
1111         if (pp->busy)
1112                 return -EBUSY;
1113         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1114                 return -EFAULT;
1115         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1116                 pp->mode = smu_file_events;
1117                 return 0;
1118         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1119                 const struct smu_sdbp_header *part;
1120                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1121                 if (part == NULL)
1122                         return -EINVAL;
1123                 else if (IS_ERR(part))
1124                         return PTR_ERR(part);
1125                 return 0;
1126         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1127                 return -EINVAL;
1128         else if (pp->mode != smu_file_commands)
1129                 return -EBADFD;
1130         else if (hdr.data_len > SMU_MAX_DATA)
1131                 return -EINVAL;
1132
1133         spin_lock_irqsave(&pp->lock, flags);
1134         if (pp->busy) {
1135                 spin_unlock_irqrestore(&pp->lock, flags);
1136                 return -EBUSY;
1137         }
1138         pp->busy = 1;
1139         pp->cmd.status = 1;
1140         spin_unlock_irqrestore(&pp->lock, flags);
1141
1142         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1143                 pp->busy = 0;
1144                 return -EFAULT;
1145         }
1146
1147         pp->cmd.cmd = hdr.cmd;
1148         pp->cmd.data_len = hdr.data_len;
1149         pp->cmd.reply_len = SMU_MAX_DATA;
1150         pp->cmd.data_buf = pp->buffer;
1151         pp->cmd.reply_buf = pp->buffer;
1152         pp->cmd.done = smu_user_cmd_done;
1153         pp->cmd.misc = pp;
1154         rc = smu_queue_cmd(&pp->cmd);
1155         if (rc < 0)
1156                 return rc;
1157         return count;
1158 }
1159
1160
1161 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1162                                 char __user *buf, size_t count)
1163 {
1164         DECLARE_WAITQUEUE(wait, current);
1165         struct smu_user_reply_hdr hdr;
1166         unsigned long flags;
1167         int size, rc = 0;
1168
1169         if (!pp->busy)
1170                 return 0;
1171         if (count < sizeof(struct smu_user_reply_hdr))
1172                 return -EOVERFLOW;
1173         spin_lock_irqsave(&pp->lock, flags);
1174         if (pp->cmd.status == 1) {
1175                 if (file->f_flags & O_NONBLOCK)
1176                         return -EAGAIN;
1177                 add_wait_queue(&pp->wait, &wait);
1178                 for (;;) {
1179                         set_current_state(TASK_INTERRUPTIBLE);
1180                         rc = 0;
1181                         if (pp->cmd.status != 1)
1182                                 break;
1183                         rc = -ERESTARTSYS;
1184                         if (signal_pending(current))
1185                                 break;
1186                         spin_unlock_irqrestore(&pp->lock, flags);
1187                         schedule();
1188                         spin_lock_irqsave(&pp->lock, flags);
1189                 }
1190                 set_current_state(TASK_RUNNING);
1191                 remove_wait_queue(&pp->wait, &wait);
1192         }
1193         spin_unlock_irqrestore(&pp->lock, flags);
1194         if (rc)
1195                 return rc;
1196         if (pp->cmd.status != 0)
1197                 pp->cmd.reply_len = 0;
1198         size = sizeof(hdr) + pp->cmd.reply_len;
1199         if (count < size)
1200                 size = count;
1201         rc = size;
1202         hdr.status = pp->cmd.status;
1203         hdr.reply_len = pp->cmd.reply_len;
1204         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1205                 return -EFAULT;
1206         size -= sizeof(hdr);
1207         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1208                 return -EFAULT;
1209         pp->busy = 0;
1210
1211         return rc;
1212 }
1213
1214
1215 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1216                                char __user *buf, size_t count)
1217 {
1218         /* Not implemented */
1219         msleep_interruptible(1000);
1220         return 0;
1221 }
1222
1223
1224 static ssize_t smu_read(struct file *file, char __user *buf,
1225                         size_t count, loff_t *ppos)
1226 {
1227         struct smu_private *pp = file->private_data;
1228
1229         if (pp->mode == smu_file_commands)
1230                 return smu_read_command(file, pp, buf, count);
1231         if (pp->mode == smu_file_events)
1232                 return smu_read_events(file, pp, buf, count);
1233
1234         return -EBADFD;
1235 }
1236
1237 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1238 {
1239         struct smu_private *pp = file->private_data;
1240         unsigned int mask = 0;
1241         unsigned long flags;
1242
1243         if (pp == 0)
1244                 return 0;
1245
1246         if (pp->mode == smu_file_commands) {
1247                 poll_wait(file, &pp->wait, wait);
1248
1249                 spin_lock_irqsave(&pp->lock, flags);
1250                 if (pp->busy && pp->cmd.status != 1)
1251                         mask |= POLLIN;
1252                 spin_unlock_irqrestore(&pp->lock, flags);
1253         } if (pp->mode == smu_file_events) {
1254                 /* Not yet implemented */
1255         }
1256         return mask;
1257 }
1258
1259 static int smu_release(struct inode *inode, struct file *file)
1260 {
1261         struct smu_private *pp = file->private_data;
1262         unsigned long flags;
1263         unsigned int busy;
1264
1265         if (pp == 0)
1266                 return 0;
1267
1268         file->private_data = NULL;
1269
1270         /* Mark file as closing to avoid races with new request */
1271         spin_lock_irqsave(&pp->lock, flags);
1272         pp->mode = smu_file_closing;
1273         busy = pp->busy;
1274
1275         /* Wait for any pending request to complete */
1276         if (busy && pp->cmd.status == 1) {
1277                 DECLARE_WAITQUEUE(wait, current);
1278
1279                 add_wait_queue(&pp->wait, &wait);
1280                 for (;;) {
1281                         set_current_state(TASK_UNINTERRUPTIBLE);
1282                         if (pp->cmd.status != 1)
1283                                 break;
1284                         spin_unlock_irqrestore(&pp->lock, flags);
1285                         schedule();
1286                         spin_lock_irqsave(&pp->lock, flags);
1287                 }
1288                 set_current_state(TASK_RUNNING);
1289                 remove_wait_queue(&pp->wait, &wait);
1290         }
1291         spin_unlock_irqrestore(&pp->lock, flags);
1292
1293         spin_lock_irqsave(&smu_clist_lock, flags);
1294         list_del(&pp->list);
1295         spin_unlock_irqrestore(&smu_clist_lock, flags);
1296         kfree(pp);
1297
1298         return 0;
1299 }
1300
1301
1302 static const struct file_operations smu_device_fops = {
1303         .llseek         = no_llseek,
1304         .read           = smu_read,
1305         .write          = smu_write,
1306         .poll           = smu_fpoll,
1307         .open           = smu_open,
1308         .release        = smu_release,
1309 };
1310
1311 static struct miscdevice pmu_device = {
1312         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1313 };
1314
1315 static int smu_device_init(void)
1316 {
1317         if (!smu)
1318                 return -ENODEV;
1319         if (misc_register(&pmu_device) < 0)
1320                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1321         return 0;
1322 }
1323 device_initcall(smu_device_init);