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   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/smp_lock.h>
  23 #include <linux/types.h>
  24 #include <linux/kernel.h>
  25 #include <linux/device.h>
  26 #include <linux/dmapool.h>
  27 #include <linux/bootmem.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/highmem.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/rtc.h>
  33 #include <linux/completion.h>
  34 #include <linux/miscdevice.h>
  35 #include <linux/delay.h>
  36 #include <linux/sysdev.h>
  37 #include <linux/poll.h>
  38 #include <linux/mutex.h>
  39
  40 #include <asm/byteorder.h>
  41 #include <asm/io.h>
  42 #include <asm/prom.h>
  43 #include <asm/machdep.h>
  44 #include <asm/pmac_feature.h>
  45 #include <asm/smu.h>
  46 #include <asm/sections.h>
  47 #include <asm/abs_addr.h>
  48 #include <asm/uaccess.h>
  49 #include <asm/of_device.h>
  50 #include <asm/of_platform.h>
  51
  52 #define VERSION "0.7"
  53 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  54
  55 #undef DEBUG_SMU
  56
  57 #ifdef DEBUG_SMU
  58 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  59 #else
  60 #define DPRINTK(fmt, args...) do { } while (0)
  61 #endif
  62
  63 /*
  64  * This is the command buffer passed to the SMU hardware
  65  */
  66 #define SMU_MAX_DATA    254
  67
  68 struct smu_cmd_buf {
  69         u8 cmd;
  70         u8 length;
  71         u8 data[SMU_MAX_DATA];
  72 };
  73
  74 struct smu_device {
  75         spinlock_t              lock;
  76         struct device_node      *of_node;
  77         struct of_device        *of_dev;
  78         int                     doorbell;       /* doorbell gpio */
  79         u32 __iomem             *db_buf;        /* doorbell buffer */
  80         struct device_node      *db_node;
  81         unsigned int            db_irq;
  82         int                     msg;
  83         struct device_node      *msg_node;
  84         unsigned int            msg_irq;
  85         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  86         u32                     cmd_buf_abs;    /* command buffer absolute */
  87         struct list_head        cmd_list;
  88         struct smu_cmd          *cmd_cur;       /* pending command */
  89         int                     broken_nap;
  90         struct list_head        cmd_i2c_list;
  91         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  92         struct timer_list       i2c_timer;
  93 };
  94
  95 /*
  96  * I don't think there will ever be more than one SMU, so
  97  * for now, just hard code that
  98  */
  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: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 125                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 126                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 127                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 128                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 129
 130         /* Fill the SMU command buffer */
 131         smu->cmd_buf->cmd = cmd->cmd;
 132         smu->cmd_buf->length = cmd->data_len;
 133         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 134
 135         /* Flush command and data to RAM */
 136         faddr = (unsigned long)smu->cmd_buf;
 137         fend = faddr + smu->cmd_buf->length + 2;
 138         flush_inval_dcache_range(faddr, fend);
 139
 140
 141         /* We also disable NAP mode for the duration of the command
 142          * on U3 based machines.
 143          * This is slightly racy as it can be written back to 1 by a sysctl
 144          * but that never happens in practice. There seem to be an issue with
 145          * U3 based machines such as the iMac G5 where napping for the
 146          * whole duration of the command prevents the SMU from fetching it
 147          * from memory. This might be related to the strange i2c based
 148          * mechanism the SMU uses to access memory.
 149          */
 150         if (smu->broken_nap)
 151                 powersave_nap = 0;
 152
 153         /* This isn't exactly a DMA mapping here, I suspect
 154          * the SMU is actually communicating with us via i2c to the
 155          * northbridge or the CPU to access RAM.
 156          */
 157         writel(smu->cmd_buf_abs, smu->db_buf);
 158
 159         /* Ring the SMU doorbell */
 160         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 161 }
 162
 163
 164 static irqreturn_t smu_db_intr(int irq, void *arg)
 165 {
 166         unsigned long flags;
 167         struct smu_cmd *cmd;
 168         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 169         void *misc = NULL;
 170         u8 gpio;
 171         int rc = 0;
 172
 173         /* SMU completed the command, well, we hope, let's make sure
 174          * of it
 175          */
 176         spin_lock_irqsave(&smu->lock, flags);
 177
 178         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 179         if ((gpio & 7) != 7) {
 180                 spin_unlock_irqrestore(&smu->lock, flags);
 181                 return IRQ_HANDLED;
 182         }
 183
 184         cmd = smu->cmd_cur;
 185         smu->cmd_cur = NULL;
 186         if (cmd == NULL)
 187                 goto bail;
 188
 189         if (rc == 0) {
 190                 unsigned long faddr;
 191                 int reply_len;
 192                 u8 ack;
 193
 194                 /* CPU might have brought back the cache line, so we need
 195                  * to flush again before peeking at the SMU response. We
 196                  * flush the entire buffer for now as we haven't read the
 197                  * reply length (it's only 2 cache lines anyway)
 198                  */
 199                 faddr = (unsigned long)smu->cmd_buf;
 200                 flush_inval_dcache_range(faddr, faddr + 256);
 201
 202                 /* Now check ack */
 203                 ack = (~cmd->cmd) & 0xff;
 204                 if (ack != smu->cmd_buf->cmd) {
 205                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 206                                 ack, smu->cmd_buf->cmd);
 207                         rc = -EIO;
 208                 }
 209                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 210                 DPRINTK("SMU: reply len: %d\n", reply_len);
 211                 if (reply_len > cmd->reply_len) {
 212                         printk(KERN_WARNING "SMU: reply buffer too small,"
 213                                "got %d bytes for a %d bytes buffer\n",
 214                                reply_len, cmd->reply_len);
 215                         reply_len = cmd->reply_len;
 216                 }
 217                 cmd->reply_len = reply_len;
 218                 if (cmd->reply_buf && reply_len)
 219                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 220         }
 221
 222         /* Now complete the command. Write status last in order as we lost
 223          * ownership of the command structure as soon as it's no longer -1
 224          */
 225         done = cmd->done;
 226         misc = cmd->misc;
 227         mb();
 228         cmd->status = rc;
 229
 230         /* Re-enable NAP mode */
 231         if (smu->broken_nap)
 232                 powersave_nap = 1;
 233  bail:
 234         /* Start next command if any */
 235         smu_start_cmd();
 236         spin_unlock_irqrestore(&smu->lock, flags);
 237
 238         /* Call command completion handler if any */
 239         if (done)
 240                 done(cmd, misc);
 241
 242         /* It's an edge interrupt, nothing to do */
 243         return IRQ_HANDLED;
 244 }
 245
 246
 247 static irqreturn_t smu_msg_intr(int irq, void *arg)
 248 {
 249         /* I don't quite know what to do with this one, we seem to never
 250          * receive it, so I suspect we have to arm it someway in the SMU
 251          * to start getting events that way.
 252          */
 253
 254         printk(KERN_INFO "SMU: message interrupt !\n");
 255
 256         /* It's an edge interrupt, nothing to do */
 257         return IRQ_HANDLED;
 258 }
 259
 260
 261 /*
 262  * Queued command management.
 263  *
 264  */
 265
 266 int smu_queue_cmd(struct smu_cmd *cmd)
 267 {
 268         unsigned long flags;
 269
 270         if (smu == NULL)
 271                 return -ENODEV;
 272         if (cmd->data_len > SMU_MAX_DATA ||
 273             cmd->reply_len > SMU_MAX_DATA)
 274                 return -EINVAL;
 275
 276         cmd->status = 1;
 277         spin_lock_irqsave(&smu->lock, flags);
 278         list_add_tail(&cmd->link, &smu->cmd_list);
 279         if (smu->cmd_cur == NULL)
 280                 smu_start_cmd();
 281         spin_unlock_irqrestore(&smu->lock, flags);
 282
 283         /* Workaround for early calls when irq isn't available */
 284         if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 285                 smu_spinwait_cmd(cmd);
 286
 287         return 0;
 288 }
 289 EXPORT_SYMBOL(smu_queue_cmd);
 290
 291
 292 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 293                      unsigned int data_len,
 294                      void (*done)(struct smu_cmd *cmd, void *misc),
 295                      void *misc, ...)
 296 {
 297         struct smu_cmd *cmd = &scmd->cmd;
 298         va_list list;
 299         int i;
 300
 301         if (data_len > sizeof(scmd->buffer))
 302                 return -EINVAL;
 303
 304         memset(scmd, 0, sizeof(*scmd));
 305         cmd->cmd = command;
 306         cmd->data_len = data_len;
 307         cmd->data_buf = scmd->buffer;
 308         cmd->reply_len = sizeof(scmd->buffer);
 309         cmd->reply_buf = scmd->buffer;
 310         cmd->done = done;
 311         cmd->misc = misc;
 312
 313         va_start(list, misc);
 314         for (i = 0; i < data_len; ++i)
 315                 scmd->buffer[i] = (u8)va_arg(list, int);
 316         va_end(list);
 317
 318         return smu_queue_cmd(cmd);
 319 }
 320 EXPORT_SYMBOL(smu_queue_simple);
 321
 322
 323 void smu_poll(void)
 324 {
 325         u8 gpio;
 326
 327         if (smu == NULL)
 328                 return;
 329
 330         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 331         if ((gpio & 7) == 7)
 332                 smu_db_intr(smu->db_irq, smu);
 333 }
 334 EXPORT_SYMBOL(smu_poll);
 335
 336
 337 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 338 {
 339         struct completion *comp = misc;
 340
 341         complete(comp);
 342 }
 343 EXPORT_SYMBOL(smu_done_complete);
 344
 345
 346 void smu_spinwait_cmd(struct smu_cmd *cmd)
 347 {
 348         while(cmd->status == 1)
 349                 smu_poll();
 350 }
 351 EXPORT_SYMBOL(smu_spinwait_cmd);
 352
 353
 354 /* RTC low level commands */
 355 static inline int bcd2hex (int n)
 356 {
 357         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 358 }
 359
 360
 361 static inline int hex2bcd (int n)
 362 {
 363         return ((n / 10) << 4) + (n % 10);
 364 }
 365
 366
 367 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 368                                         struct rtc_time *time)
 369 {
 370         cmd_buf->cmd = 0x8e;
 371         cmd_buf->length = 8;
 372         cmd_buf->data[0] = 0x80;
 373         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 374         cmd_buf->data[2] = hex2bcd(time->tm_min);
 375         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 376         cmd_buf->data[4] = time->tm_wday;
 377         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 378         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 379         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 380 }
 381
 382
 383 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 384 {
 385         struct smu_simple_cmd cmd;
 386         int rc;
 387
 388         if (smu == NULL)
 389                 return -ENODEV;
 390
 391         memset(time, 0, sizeof(struct rtc_time));
 392         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 393                               SMU_CMD_RTC_GET_DATETIME);
 394         if (rc)
 395                 return rc;
 396         smu_spinwait_simple(&cmd);
 397
 398         time->tm_sec = bcd2hex(cmd.buffer[0]);
 399         time->tm_min = bcd2hex(cmd.buffer[1]);
 400         time->tm_hour = bcd2hex(cmd.buffer[2]);
 401         time->tm_wday = bcd2hex(cmd.buffer[3]);
 402         time->tm_mday = bcd2hex(cmd.buffer[4]);
 403         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 404         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 405
 406         return 0;
 407 }
 408
 409
 410 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 411 {
 412         struct smu_simple_cmd cmd;
 413         int rc;
 414
 415         if (smu == NULL)
 416                 return -ENODEV;
 417
 418         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 419                               SMU_CMD_RTC_SET_DATETIME,
 420                               hex2bcd(time->tm_sec),
 421                               hex2bcd(time->tm_min),
 422                               hex2bcd(time->tm_hour),
 423                               time->tm_wday,
 424                               hex2bcd(time->tm_mday),
 425                               hex2bcd(time->tm_mon) + 1,
 426                               hex2bcd(time->tm_year - 100));
 427         if (rc)
 428                 return rc;
 429         smu_spinwait_simple(&cmd);
 430
 431         return 0;
 432 }
 433
 434
 435 void smu_shutdown(void)
 436 {
 437         struct smu_simple_cmd cmd;
 438
 439         if (smu == NULL)
 440                 return;
 441
 442         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 443                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 444                 return;
 445         smu_spinwait_simple(&cmd);
 446         for (;;)
 447                 ;
 448 }
 449
 450
 451 void smu_restart(void)
 452 {
 453         struct smu_simple_cmd cmd;
 454
 455         if (smu == NULL)
 456                 return;
 457
 458         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 459                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 460                 return;
 461         smu_spinwait_simple(&cmd);
 462         for (;;)
 463                 ;
 464 }
 465
 466
 467 int smu_present(void)
 468 {
 469         return smu != NULL;
 470 }
 471 EXPORT_SYMBOL(smu_present);
 472
 473
 474 int __init smu_init (void)
 475 {
 476         struct device_node *np;
 477         const u32 *data;
 478
 479         np = of_find_node_by_type(NULL, "smu");
 480         if (np == NULL)
 481                 return -ENODEV;
 482
 483         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 484
 485         if (smu_cmdbuf_abs == 0) {
 486                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 487                 of_node_put(np);
 488                 return -EINVAL;
 489         }
 490
 491         smu = alloc_bootmem(sizeof(struct smu_device));
 492         if (smu == NULL) {
 493                 of_node_put(np);
 494                 return -ENOMEM;
 495         }
 496         memset(smu, 0, sizeof(*smu));
 497
 498         spin_lock_init(&smu->lock);
 499         INIT_LIST_HEAD(&smu->cmd_list);
 500         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 501         smu->of_node = np;
 502         smu->db_irq = NO_IRQ;
 503         smu->msg_irq = NO_IRQ;
 504
 505         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 506          * 32 bits value safely
 507          */
 508         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 509         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 510
 511         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 512         if (smu->db_node == NULL) {
 513                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 514                 goto fail;
 515         }
 516         data = of_get_property(smu->db_node, "reg", NULL);
 517         if (data == NULL) {
 518                 of_node_put(smu->db_node);
 519                 smu->db_node = NULL;
 520                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 521                 goto fail;
 522         }
 523
 524         /* Current setup has one doorbell GPIO that does both doorbell
 525          * and ack. GPIOs are at 0x50, best would be to find that out
 526          * in the device-tree though.
 527          */
 528         smu->doorbell = *data;
 529         if (smu->doorbell < 0x50)
 530                 smu->doorbell += 0x50;
 531
 532         /* Now look for the smu-interrupt GPIO */
 533         do {
 534                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 535                 if (smu->msg_node == NULL)
 536                         break;
 537                 data = of_get_property(smu->msg_node, "reg", NULL);
 538                 if (data == NULL) {
 539                         of_node_put(smu->msg_node);
 540                         smu->msg_node = NULL;
 541                         break;
 542                 }
 543                 smu->msg = *data;
 544                 if (smu->msg < 0x50)
 545                         smu->msg += 0x50;
 546         } while(0);
 547
 548         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 549          * device-tree entry giving the address. Best would probably to use
 550          * an offset for K2 base though, but let's do it that way for now.
 551          */
 552         smu->db_buf = ioremap(0x8000860c, 0x1000);
 553         if (smu->db_buf == NULL) {
 554                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 555                 goto fail;
 556         }
 557
 558         /* U3 has an issue with NAP mode when issuing SMU commands */
 559         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 560         if (smu->broken_nap)
 561                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 562
 563         sys_ctrler = SYS_CTRLER_SMU;
 564         return 0;
 565
 566  fail:
 567         smu = NULL;
 568         return -ENXIO;
 569
 570 }
 571
 572
 573 static int smu_late_init(void)
 574 {
 575         if (!smu)
 576                 return 0;
 577
 578         init_timer(&smu->i2c_timer);
 579         smu->i2c_timer.function = smu_i2c_retry;
 580         smu->i2c_timer.data = (unsigned long)smu;
 581
 582         if (smu->db_node) {
 583                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 584                 if (smu->db_irq == NO_IRQ)
 585                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 586                                smu->db_node->full_name);
 587         }
 588         if (smu->msg_node) {
 589                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 590                 if (smu->msg_irq == NO_IRQ)
 591                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 592                                smu->msg_node->full_name);
 593         }
 594
 595         /*
 596          * Try to request the interrupts
 597          */
 598
 599         if (smu->db_irq != NO_IRQ) {
 600                 if (request_irq(smu->db_irq, smu_db_intr,
 601                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 602                         printk(KERN_WARNING "SMU: can't "
 603                                "request interrupt %d\n",
 604                                smu->db_irq);
 605                         smu->db_irq = NO_IRQ;
 606                 }
 607         }
 608
 609         if (smu->msg_irq != NO_IRQ) {
 610                 if (request_irq(smu->msg_irq, smu_msg_intr,
 611                                 IRQF_SHARED, "SMU message", smu) < 0) {
 612                         printk(KERN_WARNING "SMU: can't "
 613                                "request interrupt %d\n",
 614                                smu->msg_irq);
 615                         smu->msg_irq = NO_IRQ;
 616                 }
 617         }
 618
 619         smu_irq_inited = 1;
 620         return 0;
 621 }
 622 /* This has to be before arch_initcall as the low i2c stuff relies on the
 623  * above having been done before we reach arch_initcalls
 624  */
 625 core_initcall(smu_late_init);
 626
 627 /*
 628  * sysfs visibility
 629  */
 630
 631 static void smu_expose_childs(struct work_struct *unused)
 632 {
 633         struct device_node *np;
 634
 635         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 636                 if (of_device_is_compatible(np, "smu-sensors"))
 637                         of_platform_device_create(np, "smu-sensors",
 638                                                   &smu->of_dev->dev);
 639 }
 640
 641 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 642
 643 static int smu_platform_probe(struct of_device* dev,
 644                               const struct of_device_id *match)
 645 {
 646         if (!smu)
 647                 return -ENODEV;
 648         smu->of_dev = dev;
 649
 650         /*
 651          * Ok, we are matched, now expose all i2c busses. We have to defer
 652          * that unfortunately or it would deadlock inside the device model
 653          */
 654         schedule_work(&smu_expose_childs_work);
 655
 656         return 0;
 657 }
 658
 659 static struct of_device_id smu_platform_match[] =
 660 {
 661         {
 662                 .type           = "smu",
 663         },
 664         {},
 665 };
 666
 667 static struct of_platform_driver smu_of_platform_driver =
 668 {
 669         .name           = "smu",
 670         .match_table    = smu_platform_match,
 671         .probe          = smu_platform_probe,
 672 };
 673
 674 static int __init smu_init_sysfs(void)
 675 {
 676         /*
 677          * Due to sysfs bogosity, a sysdev is not a real device, so
 678          * we should in fact create both if we want sysdev semantics
 679          * for power management.
 680          * For now, we don't power manage machines with an SMU chip,
 681          * I'm a bit too far from figuring out how that works with those
 682          * new chipsets, but that will come back and bite us
 683          */
 684         of_register_platform_driver(&smu_of_platform_driver);
 685         return 0;
 686 }
 687
 688 device_initcall(smu_init_sysfs);
 689
 690 struct of_device *smu_get_ofdev(void)
 691 {
 692         if (!smu)
 693                 return NULL;
 694         return smu->of_dev;
 695 }
 696
 697 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 698
 699 /*
 700  * i2c interface
 701  */
 702
 703 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 704 {
 705         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 706         void *misc = cmd->misc;
 707         unsigned long flags;
 708
 709         /* Check for read case */
 710         if (!fail && cmd->read) {
 711                 if (cmd->pdata[0] < 1)
 712                         fail = 1;
 713                 else
 714                         memcpy(cmd->info.data, &cmd->pdata[1],
 715                                cmd->info.datalen);
 716         }
 717
 718         DPRINTK("SMU: completing, success: %d\n", !fail);
 719
 720         /* Update status and mark no pending i2c command with lock
 721          * held so nobody comes in while we dequeue an eventual
 722          * pending next i2c command
 723          */
 724         spin_lock_irqsave(&smu->lock, flags);
 725         smu->cmd_i2c_cur = NULL;
 726         wmb();
 727         cmd->status = fail ? -EIO : 0;
 728
 729         /* Is there another i2c command waiting ? */
 730         if (!list_empty(&smu->cmd_i2c_list)) {
 731                 struct smu_i2c_cmd *newcmd;
 732
 733                 /* Fetch it, new current, remove from list */
 734                 newcmd = list_entry(smu->cmd_i2c_list.next,
 735                                     struct smu_i2c_cmd, link);
 736                 smu->cmd_i2c_cur = newcmd;
 737                 list_del(&cmd->link);
 738
 739                 /* Queue with low level smu */
 740                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 741                 if (smu->cmd_cur == NULL)
 742                         smu_start_cmd();
 743         }
 744         spin_unlock_irqrestore(&smu->lock, flags);
 745
 746         /* Call command completion handler if any */
 747         if (done)
 748                 done(cmd, misc);
 749
 750 }
 751
 752
 753 static void smu_i2c_retry(unsigned long data)
 754 {
 755         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 756
 757         DPRINTK("SMU: i2c failure, requeuing...\n");
 758
 759         /* requeue command simply by resetting reply_len */
 760         cmd->pdata[0] = 0xff;
 761         cmd->scmd.reply_len = sizeof(cmd->pdata);
 762         smu_queue_cmd(&cmd->scmd);
 763 }
 764
 765
 766 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 767 {
 768         struct smu_i2c_cmd      *cmd = misc;
 769         int                     fail = 0;
 770
 771         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 772                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 773
 774         /* Check for possible status */
 775         if (scmd->status < 0)
 776                 fail = 1;
 777         else if (cmd->read) {
 778                 if (cmd->stage == 0)
 779                         fail = cmd->pdata[0] != 0;
 780                 else
 781                         fail = cmd->pdata[0] >= 0x80;
 782         } else {
 783                 fail = cmd->pdata[0] != 0;
 784         }
 785
 786         /* Handle failures by requeuing command, after 5ms interval
 787          */
 788         if (fail && --cmd->retries > 0) {
 789                 DPRINTK("SMU: i2c failure, starting timer...\n");
 790                 BUG_ON(cmd != smu->cmd_i2c_cur);
 791                 if (!smu_irq_inited) {
 792                         mdelay(5);
 793                         smu_i2c_retry(0);
 794                         return;
 795                 }
 796                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 797                 return;
 798         }
 799
 800         /* If failure or stage 1, command is complete */
 801         if (fail || cmd->stage != 0) {
 802                 smu_i2c_complete_command(cmd, fail);
 803                 return;
 804         }
 805
 806         DPRINTK("SMU: going to stage 1\n");
 807
 808         /* Ok, initial command complete, now poll status */
 809         scmd->reply_buf = cmd->pdata;
 810         scmd->reply_len = sizeof(cmd->pdata);
 811         scmd->data_buf = cmd->pdata;
 812         scmd->data_len = 1;
 813         cmd->pdata[0] = 0;
 814         cmd->stage = 1;
 815         cmd->retries = 20;
 816         smu_queue_cmd(scmd);
 817 }
 818
 819
 820 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 821 {
 822         unsigned long flags;
 823
 824         if (smu == NULL)
 825                 return -ENODEV;
 826
 827         /* Fill most fields of scmd */
 828         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 829         cmd->scmd.done = smu_i2c_low_completion;
 830         cmd->scmd.misc = cmd;
 831         cmd->scmd.reply_buf = cmd->pdata;
 832         cmd->scmd.reply_len = sizeof(cmd->pdata);
 833         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 834         cmd->scmd.status = 1;
 835         cmd->stage = 0;
 836         cmd->pdata[0] = 0xff;
 837         cmd->retries = 20;
 838         cmd->status = 1;
 839
 840         /* Check transfer type, sanitize some "info" fields
 841          * based on transfer type and do more checking
 842          */
 843         cmd->info.caddr = cmd->info.devaddr;
 844         cmd->read = cmd->info.devaddr & 0x01;
 845         switch(cmd->info.type) {
 846         case SMU_I2C_TRANSFER_SIMPLE:
 847                 memset(&cmd->info.sublen, 0, 4);
 848                 break;
 849         case SMU_I2C_TRANSFER_COMBINED:
 850                 cmd->info.devaddr &= 0xfe;
 851         case SMU_I2C_TRANSFER_STDSUB:
 852                 if (cmd->info.sublen > 3)
 853                         return -EINVAL;
 854                 break;
 855         default:
 856                 return -EINVAL;
 857         }
 858
 859         /* Finish setting up command based on transfer direction
 860          */
 861         if (cmd->read) {
 862                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 863                         return -EINVAL;
 864                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 865                 cmd->scmd.data_len = 9;
 866         } else {
 867                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 868                         return -EINVAL;
 869                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 870         }
 871
 872         DPRINTK("SMU: i2c enqueuing command\n");
 873         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 874                 cmd->read ? "read" : "write", cmd->info.datalen,
 875                 cmd->info.bus, cmd->info.caddr,
 876                 cmd->info.subaddr[0], cmd->info.type);
 877
 878
 879         /* Enqueue command in i2c list, and if empty, enqueue also in
 880          * main command list
 881          */
 882         spin_lock_irqsave(&smu->lock, flags);
 883         if (smu->cmd_i2c_cur == NULL) {
 884                 smu->cmd_i2c_cur = cmd;
 885                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 886                 if (smu->cmd_cur == NULL)
 887                         smu_start_cmd();
 888         } else
 889                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 890         spin_unlock_irqrestore(&smu->lock, flags);
 891
 892         return 0;
 893 }
 894
 895 /*
 896  * Handling of "partitions"
 897  */
 898
 899 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 900 {
 901         DECLARE_COMPLETION_ONSTACK(comp);
 902         unsigned int chunk;
 903         struct smu_cmd cmd;
 904         int rc;
 905         u8 params[8];
 906
 907         /* We currently use a chunk size of 0xe. We could check the
 908          * SMU firmware version and use bigger sizes though
 909          */
 910         chunk = 0xe;
 911
 912         while (len) {
 913                 unsigned int clen = min(len, chunk);
 914
 915                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 916                 cmd.data_len = 7;
 917                 cmd.data_buf = params;
 918                 cmd.reply_len = chunk;
 919                 cmd.reply_buf = dest;
 920                 cmd.done = smu_done_complete;
 921                 cmd.misc = &comp;
 922                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 923                 params[1] = 0x4;
 924                 *((u32 *)&params[2]) = addr;
 925                 params[6] = clen;
 926
 927                 rc = smu_queue_cmd(&cmd);
 928                 if (rc)
 929                         return rc;
 930                 wait_for_completion(&comp);
 931                 if (cmd.status != 0)
 932                         return rc;
 933                 if (cmd.reply_len != clen) {
 934                         printk(KERN_DEBUG "SMU: short read in "
 935                                "smu_read_datablock, got: %d, want: %d\n",
 936                                cmd.reply_len, clen);
 937                         return -EIO;
 938                 }
 939                 len -= clen;
 940                 addr += clen;
 941                 dest += clen;
 942         }
 943         return 0;
 944 }
 945
 946 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 947 {
 948         DECLARE_COMPLETION_ONSTACK(comp);
 949         struct smu_simple_cmd cmd;
 950         unsigned int addr, len, tlen;
 951         struct smu_sdbp_header *hdr;
 952         struct property *prop;
 953
 954         /* First query the partition info */
 955         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 956         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 957                          smu_done_complete, &comp,
 958                          SMU_CMD_PARTITION_LATEST, id);
 959         wait_for_completion(&comp);
 960         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 961                 cmd.cmd.status, cmd.cmd.reply_len);
 962
 963         /* Partition doesn't exist (or other error) */
 964         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 965                 return NULL;
 966
 967         /* Fetch address and length from reply */
 968         addr = *((u16 *)cmd.buffer);
 969         len = cmd.buffer[3] << 2;
 970         /* Calucluate total length to allocate, including the 17 bytes
 971          * for "sdb-partition-XX" that we append at the end of the buffer
 972          */
 973         tlen = sizeof(struct property) + len + 18;
 974
 975         prop = kzalloc(tlen, GFP_KERNEL);
 976         if (prop == NULL)
 977                 return NULL;
 978         hdr = (struct smu_sdbp_header *)(prop + 1);
 979         prop->name = ((char *)prop) + tlen - 18;
 980         sprintf(prop->name, "sdb-partition-%02x", id);
 981         prop->length = len;
 982         prop->value = hdr;
 983         prop->next = NULL;
 984
 985         /* Read the datablock */
 986         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 987                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 988                        "partition %02x !\n", id);
 989                 goto failure;
 990         }
 991
 992         /* Got it, check a few things and create the property */
 993         if (hdr->id != id) {
 994                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 995                        "%02x !\n", id, hdr->id);
 996                 goto failure;
 997         }
 998         if (prom_add_property(smu->of_node, prop)) {
 999                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1000                        "property !\n", id);
1001                 goto failure;
1002         }
1003
1004         return hdr;
1005  failure:
1006         kfree(prop);
1007         return NULL;
1008 }
1009
1010 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1011  * when interruptible is 1
1012  */
1013 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1014                 unsigned int *size, int interruptible)
1015 {
1016         char pname[32];
1017         const struct smu_sdbp_header *part;
1018
1019         if (!smu)
1020                 return NULL;
1021
1022         sprintf(pname, "sdb-partition-%02x", id);
1023
1024         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1025
1026         if (interruptible) {
1027                 int rc;
1028                 rc = mutex_lock_interruptible(&smu_part_access);
1029                 if (rc)
1030                         return ERR_PTR(rc);
1031         } else
1032                 mutex_lock(&smu_part_access);
1033
1034         part = of_get_property(smu->of_node, pname, size);
1035         if (part == NULL) {
1036                 DPRINTK("trying to extract from SMU ...\n");
1037                 part = smu_create_sdb_partition(id);
1038                 if (part != NULL && size)
1039                         *size = part->len << 2;
1040         }
1041         mutex_unlock(&smu_part_access);
1042         return part;
1043 }
1044
1045 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1046 {
1047         return __smu_get_sdb_partition(id, size, 0);
1048 }
1049 EXPORT_SYMBOL(smu_get_sdb_partition);
1050
1051
1052 /*
1053  * Userland driver interface
1054  */
1055
1056
1057 static LIST_HEAD(smu_clist);
1058 static DEFINE_SPINLOCK(smu_clist_lock);
1059
1060 enum smu_file_mode {
1061         smu_file_commands,
1062         smu_file_events,
1063         smu_file_closing
1064 };
1065
1066 struct smu_private
1067 {
1068         struct list_head        list;
1069         enum smu_file_mode      mode;
1070         int                     busy;
1071         struct smu_cmd          cmd;
1072         spinlock_t              lock;
1073         wait_queue_head_t       wait;
1074         u8                      buffer[SMU_MAX_DATA];
1075 };
1076
1077
1078 static int smu_open(struct inode *inode, struct file *file)
1079 {
1080         struct smu_private *pp;
1081         unsigned long flags;
1082
1083         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1084         if (pp == 0)
1085                 return -ENOMEM;
1086         spin_lock_init(&pp->lock);
1087         pp->mode = smu_file_commands;
1088         init_waitqueue_head(&pp->wait);
1089
1090         lock_kernel();
1091         spin_lock_irqsave(&smu_clist_lock, flags);
1092         list_add(&pp->list, &smu_clist);
1093         spin_unlock_irqrestore(&smu_clist_lock, flags);
1094         file->private_data = pp;
1095         unlock_kernel();
1096
1097         return 0;
1098 }
1099
1100
1101 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1102 {
1103         struct smu_private *pp = misc;
1104
1105         wake_up_all(&pp->wait);
1106 }
1107
1108
1109 static ssize_t smu_write(struct file *file, const char __user *buf,
1110                          size_t count, loff_t *ppos)
1111 {
1112         struct smu_private *pp = file->private_data;
1113         unsigned long flags;
1114         struct smu_user_cmd_hdr hdr;
1115         int rc = 0;
1116
1117         if (pp->busy)
1118                 return -EBUSY;
1119         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1120                 return -EFAULT;
1121         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1122                 pp->mode = smu_file_events;
1123                 return 0;
1124         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1125                 const struct smu_sdbp_header *part;
1126                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1127                 if (part == NULL)
1128                         return -EINVAL;
1129                 else if (IS_ERR(part))
1130                         return PTR_ERR(part);
1131                 return 0;
1132         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1133                 return -EINVAL;
1134         else if (pp->mode != smu_file_commands)
1135                 return -EBADFD;
1136         else if (hdr.data_len > SMU_MAX_DATA)
1137                 return -EINVAL;
1138
1139         spin_lock_irqsave(&pp->lock, flags);
1140         if (pp->busy) {
1141                 spin_unlock_irqrestore(&pp->lock, flags);
1142                 return -EBUSY;
1143         }
1144         pp->busy = 1;
1145         pp->cmd.status = 1;
1146         spin_unlock_irqrestore(&pp->lock, flags);
1147
1148         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1149                 pp->busy = 0;
1150                 return -EFAULT;
1151         }
1152
1153         pp->cmd.cmd = hdr.cmd;
1154         pp->cmd.data_len = hdr.data_len;
1155         pp->cmd.reply_len = SMU_MAX_DATA;
1156         pp->cmd.data_buf = pp->buffer;
1157         pp->cmd.reply_buf = pp->buffer;
1158         pp->cmd.done = smu_user_cmd_done;
1159         pp->cmd.misc = pp;
1160         rc = smu_queue_cmd(&pp->cmd);
1161         if (rc < 0)
1162                 return rc;
1163         return count;
1164 }
1165
1166
1167 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1168                                 char __user *buf, size_t count)
1169 {
1170         DECLARE_WAITQUEUE(wait, current);
1171         struct smu_user_reply_hdr hdr;
1172         unsigned long flags;
1173         int size, rc = 0;
1174
1175         if (!pp->busy)
1176                 return 0;
1177         if (count < sizeof(struct smu_user_reply_hdr))
1178                 return -EOVERFLOW;
1179         spin_lock_irqsave(&pp->lock, flags);
1180         if (pp->cmd.status == 1) {
1181                 if (file->f_flags & O_NONBLOCK)
1182                         return -EAGAIN;
1183                 add_wait_queue(&pp->wait, &wait);
1184                 for (;;) {
1185                         set_current_state(TASK_INTERRUPTIBLE);
1186                         rc = 0;
1187                         if (pp->cmd.status != 1)
1188                                 break;
1189                         rc = -ERESTARTSYS;
1190                         if (signal_pending(current))
1191                                 break;
1192                         spin_unlock_irqrestore(&pp->lock, flags);
1193                         schedule();
1194                         spin_lock_irqsave(&pp->lock, flags);
1195                 }
1196                 set_current_state(TASK_RUNNING);
1197                 remove_wait_queue(&pp->wait, &wait);
1198         }
1199         spin_unlock_irqrestore(&pp->lock, flags);
1200         if (rc)
1201                 return rc;
1202         if (pp->cmd.status != 0)
1203                 pp->cmd.reply_len = 0;
1204         size = sizeof(hdr) + pp->cmd.reply_len;
1205         if (count < size)
1206                 size = count;
1207         rc = size;
1208         hdr.status = pp->cmd.status;
1209         hdr.reply_len = pp->cmd.reply_len;
1210         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1211                 return -EFAULT;
1212         size -= sizeof(hdr);
1213         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1214                 return -EFAULT;
1215         pp->busy = 0;
1216
1217         return rc;
1218 }
1219
1220
1221 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1222                                char __user *buf, size_t count)
1223 {
1224         /* Not implemented */
1225         msleep_interruptible(1000);
1226         return 0;
1227 }
1228
1229
1230 static ssize_t smu_read(struct file *file, char __user *buf,
1231                         size_t count, loff_t *ppos)
1232 {
1233         struct smu_private *pp = file->private_data;
1234
1235         if (pp->mode == smu_file_commands)
1236                 return smu_read_command(file, pp, buf, count);
1237         if (pp->mode == smu_file_events)
1238                 return smu_read_events(file, pp, buf, count);
1239
1240         return -EBADFD;
1241 }
1242
1243 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1244 {
1245         struct smu_private *pp = file->private_data;
1246         unsigned int mask = 0;
1247         unsigned long flags;
1248
1249         if (pp == 0)
1250                 return 0;
1251
1252         if (pp->mode == smu_file_commands) {
1253                 poll_wait(file, &pp->wait, wait);
1254
1255                 spin_lock_irqsave(&pp->lock, flags);
1256                 if (pp->busy && pp->cmd.status != 1)
1257                         mask |= POLLIN;
1258                 spin_unlock_irqrestore(&pp->lock, flags);
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);