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                 of_node_put(np);
 487                 return -EINVAL;
 488         }
 489
 490         smu = alloc_bootmem(sizeof(struct smu_device));
 491         if (smu == NULL) {
 492                 of_node_put(np);
 493                 return -ENOMEM;
 494         }
 495         memset(smu, 0, sizeof(*smu));
 496
 497         spin_lock_init(&smu->lock);
 498         INIT_LIST_HEAD(&smu->cmd_list);
 499         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 500         smu->of_node = np;
 501         smu->db_irq = NO_IRQ;
 502         smu->msg_irq = NO_IRQ;
 503
 504         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 505          * 32 bits value safely
 506          */
 507         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 508         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 509
 510         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 511         if (smu->db_node == NULL) {
 512                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 513                 goto fail;
 514         }
 515         data = of_get_property(smu->db_node, "reg", NULL);
 516         if (data == NULL) {
 517                 of_node_put(smu->db_node);
 518                 smu->db_node = NULL;
 519                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 520                 goto fail;
 521         }
 522
 523         /* Current setup has one doorbell GPIO that does both doorbell
 524          * and ack. GPIOs are at 0x50, best would be to find that out
 525          * in the device-tree though.
 526          */
 527         smu->doorbell = *data;
 528         if (smu->doorbell < 0x50)
 529                 smu->doorbell += 0x50;
 530
 531         /* Now look for the smu-interrupt GPIO */
 532         do {
 533                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 534                 if (smu->msg_node == NULL)
 535                         break;
 536                 data = of_get_property(smu->msg_node, "reg", NULL);
 537                 if (data == NULL) {
 538                         of_node_put(smu->msg_node);
 539                         smu->msg_node = NULL;
 540                         break;
 541                 }
 542                 smu->msg = *data;
 543                 if (smu->msg < 0x50)
 544                         smu->msg += 0x50;
 545         } while(0);
 546
 547         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 548          * device-tree entry giving the address. Best would probably to use
 549          * an offset for K2 base though, but let's do it that way for now.
 550          */
 551         smu->db_buf = ioremap(0x8000860c, 0x1000);
 552         if (smu->db_buf == NULL) {
 553                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 554                 goto fail;
 555         }
 556
 557         /* U3 has an issue with NAP mode when issuing SMU commands */
 558         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 559         if (smu->broken_nap)
 560                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 561
 562         sys_ctrler = SYS_CTRLER_SMU;
 563         return 0;
 564
 565  fail:
 566         smu = NULL;
 567         return -ENXIO;
 568
 569 }
 570
 571
 572 static int smu_late_init(void)
 573 {
 574         if (!smu)
 575                 return 0;
 576
 577         init_timer(&smu->i2c_timer);
 578         smu->i2c_timer.function = smu_i2c_retry;
 579         smu->i2c_timer.data = (unsigned long)smu;
 580
 581         if (smu->db_node) {
 582                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 583                 if (smu->db_irq == NO_IRQ)
 584                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 585                                smu->db_node->full_name);
 586         }
 587         if (smu->msg_node) {
 588                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 589                 if (smu->msg_irq == NO_IRQ)
 590                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 591                                smu->msg_node->full_name);
 592         }
 593
 594         /*
 595          * Try to request the interrupts
 596          */
 597
 598         if (smu->db_irq != NO_IRQ) {
 599                 if (request_irq(smu->db_irq, smu_db_intr,
 600                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 601                         printk(KERN_WARNING "SMU: can't "
 602                                "request interrupt %d\n",
 603                                smu->db_irq);
 604                         smu->db_irq = NO_IRQ;
 605                 }
 606         }
 607
 608         if (smu->msg_irq != NO_IRQ) {
 609                 if (request_irq(smu->msg_irq, smu_msg_intr,
 610                                 IRQF_SHARED, "SMU message", smu) < 0) {
 611                         printk(KERN_WARNING "SMU: can't "
 612                                "request interrupt %d\n",
 613                                smu->msg_irq);
 614                         smu->msg_irq = NO_IRQ;
 615                 }
 616         }
 617
 618         smu_irq_inited = 1;
 619         return 0;
 620 }
 621 /* This has to be before arch_initcall as the low i2c stuff relies on the
 622  * above having been done before we reach arch_initcalls
 623  */
 624 core_initcall(smu_late_init);
 625
 626 /*
 627  * sysfs visibility
 628  */
 629
 630 static void smu_expose_childs(struct work_struct *unused)
 631 {
 632         struct device_node *np;
 633
 634         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 635                 if (of_device_is_compatible(np, "smu-sensors"))
 636                         of_platform_device_create(np, "smu-sensors",
 637                                                   &smu->of_dev->dev);
 638 }
 639
 640 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 641
 642 static int smu_platform_probe(struct of_device* dev,
 643                               const struct of_device_id *match)
 644 {
 645         if (!smu)
 646                 return -ENODEV;
 647         smu->of_dev = dev;
 648
 649         /*
 650          * Ok, we are matched, now expose all i2c busses. We have to defer
 651          * that unfortunately or it would deadlock inside the device model
 652          */
 653         schedule_work(&smu_expose_childs_work);
 654
 655         return 0;
 656 }
 657
 658 static struct of_device_id smu_platform_match[] =
 659 {
 660         {
 661                 .type           = "smu",
 662         },
 663         {},
 664 };
 665
 666 static struct of_platform_driver smu_of_platform_driver =
 667 {
 668         .name           = "smu",
 669         .match_table    = smu_platform_match,
 670         .probe          = smu_platform_probe,
 671 };
 672
 673 static int __init smu_init_sysfs(void)
 674 {
 675         /*
 676          * Due to sysfs bogosity, a sysdev is not a real device, so
 677          * we should in fact create both if we want sysdev semantics
 678          * for power management.
 679          * For now, we don't power manage machines with an SMU chip,
 680          * I'm a bit too far from figuring out how that works with those
 681          * new chipsets, but that will come back and bite us
 682          */
 683         of_register_platform_driver(&smu_of_platform_driver);
 684         return 0;
 685 }
 686
 687 device_initcall(smu_init_sysfs);
 688
 689 struct of_device *smu_get_ofdev(void)
 690 {
 691         if (!smu)
 692                 return NULL;
 693         return smu->of_dev;
 694 }
 695
 696 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 697
 698 /*
 699  * i2c interface
 700  */
 701
 702 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 703 {
 704         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 705         void *misc = cmd->misc;
 706         unsigned long flags;
 707
 708         /* Check for read case */
 709         if (!fail && cmd->read) {
 710                 if (cmd->pdata[0] < 1)
 711                         fail = 1;
 712                 else
 713                         memcpy(cmd->info.data, &cmd->pdata[1],
 714                                cmd->info.datalen);
 715         }
 716
 717         DPRINTK("SMU: completing, success: %d\n", !fail);
 718
 719         /* Update status and mark no pending i2c command with lock
 720          * held so nobody comes in while we dequeue an eventual
 721          * pending next i2c command
 722          */
 723         spin_lock_irqsave(&smu->lock, flags);
 724         smu->cmd_i2c_cur = NULL;
 725         wmb();
 726         cmd->status = fail ? -EIO : 0;
 727
 728         /* Is there another i2c command waiting ? */
 729         if (!list_empty(&smu->cmd_i2c_list)) {
 730                 struct smu_i2c_cmd *newcmd;
 731
 732                 /* Fetch it, new current, remove from list */
 733                 newcmd = list_entry(smu->cmd_i2c_list.next,
 734                                     struct smu_i2c_cmd, link);
 735                 smu->cmd_i2c_cur = newcmd;
 736                 list_del(&cmd->link);
 737
 738                 /* Queue with low level smu */
 739                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 740                 if (smu->cmd_cur == NULL)
 741                         smu_start_cmd();
 742         }
 743         spin_unlock_irqrestore(&smu->lock, flags);
 744
 745         /* Call command completion handler if any */
 746         if (done)
 747                 done(cmd, misc);
 748
 749 }
 750
 751
 752 static void smu_i2c_retry(unsigned long data)
 753 {
 754         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 755
 756         DPRINTK("SMU: i2c failure, requeuing...\n");
 757
 758         /* requeue command simply by resetting reply_len */
 759         cmd->pdata[0] = 0xff;
 760         cmd->scmd.reply_len = sizeof(cmd->pdata);
 761         smu_queue_cmd(&cmd->scmd);
 762 }
 763
 764
 765 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 766 {
 767         struct smu_i2c_cmd      *cmd = misc;
 768         int                     fail = 0;
 769
 770         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 771                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 772
 773         /* Check for possible status */
 774         if (scmd->status < 0)
 775                 fail = 1;
 776         else if (cmd->read) {
 777                 if (cmd->stage == 0)
 778                         fail = cmd->pdata[0] != 0;
 779                 else
 780                         fail = cmd->pdata[0] >= 0x80;
 781         } else {
 782                 fail = cmd->pdata[0] != 0;
 783         }
 784
 785         /* Handle failures by requeuing command, after 5ms interval
 786          */
 787         if (fail && --cmd->retries > 0) {
 788                 DPRINTK("SMU: i2c failure, starting timer...\n");
 789                 BUG_ON(cmd != smu->cmd_i2c_cur);
 790                 if (!smu_irq_inited) {
 791                         mdelay(5);
 792                         smu_i2c_retry(0);
 793                         return;
 794                 }
 795                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 796                 return;
 797         }
 798
 799         /* If failure or stage 1, command is complete */
 800         if (fail || cmd->stage != 0) {
 801                 smu_i2c_complete_command(cmd, fail);
 802                 return;
 803         }
 804
 805         DPRINTK("SMU: going to stage 1\n");
 806
 807         /* Ok, initial command complete, now poll status */
 808         scmd->reply_buf = cmd->pdata;
 809         scmd->reply_len = sizeof(cmd->pdata);
 810         scmd->data_buf = cmd->pdata;
 811         scmd->data_len = 1;
 812         cmd->pdata[0] = 0;
 813         cmd->stage = 1;
 814         cmd->retries = 20;
 815         smu_queue_cmd(scmd);
 816 }
 817
 818
 819 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 820 {
 821         unsigned long flags;
 822
 823         if (smu == NULL)
 824                 return -ENODEV;
 825
 826         /* Fill most fields of scmd */
 827         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 828         cmd->scmd.done = smu_i2c_low_completion;
 829         cmd->scmd.misc = cmd;
 830         cmd->scmd.reply_buf = cmd->pdata;
 831         cmd->scmd.reply_len = sizeof(cmd->pdata);
 832         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 833         cmd->scmd.status = 1;
 834         cmd->stage = 0;
 835         cmd->pdata[0] = 0xff;
 836         cmd->retries = 20;
 837         cmd->status = 1;
 838
 839         /* Check transfer type, sanitize some "info" fields
 840          * based on transfer type and do more checking
 841          */
 842         cmd->info.caddr = cmd->info.devaddr;
 843         cmd->read = cmd->info.devaddr & 0x01;
 844         switch(cmd->info.type) {
 845         case SMU_I2C_TRANSFER_SIMPLE:
 846                 memset(&cmd->info.sublen, 0, 4);
 847                 break;
 848         case SMU_I2C_TRANSFER_COMBINED:
 849                 cmd->info.devaddr &= 0xfe;
 850         case SMU_I2C_TRANSFER_STDSUB:
 851                 if (cmd->info.sublen > 3)
 852                         return -EINVAL;
 853                 break;
 854         default:
 855                 return -EINVAL;
 856         }
 857
 858         /* Finish setting up command based on transfer direction
 859          */
 860         if (cmd->read) {
 861                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 862                         return -EINVAL;
 863                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 864                 cmd->scmd.data_len = 9;
 865         } else {
 866                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 867                         return -EINVAL;
 868                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 869         }
 870
 871         DPRINTK("SMU: i2c enqueuing command\n");
 872         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 873                 cmd->read ? "read" : "write", cmd->info.datalen,
 874                 cmd->info.bus, cmd->info.caddr,
 875                 cmd->info.subaddr[0], cmd->info.type);
 876
 877
 878         /* Enqueue command in i2c list, and if empty, enqueue also in
 879          * main command list
 880          */
 881         spin_lock_irqsave(&smu->lock, flags);
 882         if (smu->cmd_i2c_cur == NULL) {
 883                 smu->cmd_i2c_cur = cmd;
 884                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 885                 if (smu->cmd_cur == NULL)
 886                         smu_start_cmd();
 887         } else
 888                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 889         spin_unlock_irqrestore(&smu->lock, flags);
 890
 891         return 0;
 892 }
 893
 894 /*
 895  * Handling of "partitions"
 896  */
 897
 898 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 899 {
 900         DECLARE_COMPLETION_ONSTACK(comp);
 901         unsigned int chunk;
 902         struct smu_cmd cmd;
 903         int rc;
 904         u8 params[8];
 905
 906         /* We currently use a chunk size of 0xe. We could check the
 907          * SMU firmware version and use bigger sizes though
 908          */
 909         chunk = 0xe;
 910
 911         while (len) {
 912                 unsigned int clen = min(len, chunk);
 913
 914                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 915                 cmd.data_len = 7;
 916                 cmd.data_buf = params;
 917                 cmd.reply_len = chunk;
 918                 cmd.reply_buf = dest;
 919                 cmd.done = smu_done_complete;
 920                 cmd.misc = &comp;
 921                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 922                 params[1] = 0x4;
 923                 *((u32 *)&params[2]) = addr;
 924                 params[6] = clen;
 925
 926                 rc = smu_queue_cmd(&cmd);
 927                 if (rc)
 928                         return rc;
 929                 wait_for_completion(&comp);
 930                 if (cmd.status != 0)
 931                         return rc;
 932                 if (cmd.reply_len != clen) {
 933                         printk(KERN_DEBUG "SMU: short read in "
 934                                "smu_read_datablock, got: %d, want: %d\n",
 935                                cmd.reply_len, clen);
 936                         return -EIO;
 937                 }
 938                 len -= clen;
 939                 addr += clen;
 940                 dest += clen;
 941         }
 942         return 0;
 943 }
 944
 945 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 946 {
 947         DECLARE_COMPLETION_ONSTACK(comp);
 948         struct smu_simple_cmd cmd;
 949         unsigned int addr, len, tlen;
 950         struct smu_sdbp_header *hdr;
 951         struct property *prop;
 952
 953         /* First query the partition info */
 954         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 955         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 956                          smu_done_complete, &comp,
 957                          SMU_CMD_PARTITION_LATEST, id);
 958         wait_for_completion(&comp);
 959         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 960                 cmd.cmd.status, cmd.cmd.reply_len);
 961
 962         /* Partition doesn't exist (or other error) */
 963         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 964                 return NULL;
 965
 966         /* Fetch address and length from reply */
 967         addr = *((u16 *)cmd.buffer);
 968         len = cmd.buffer[3] << 2;
 969         /* Calucluate total length to allocate, including the 17 bytes
 970          * for "sdb-partition-XX" that we append at the end of the buffer
 971          */
 972         tlen = sizeof(struct property) + len + 18;
 973
 974         prop = kzalloc(tlen, GFP_KERNEL);
 975         if (prop == NULL)
 976                 return NULL;
 977         hdr = (struct smu_sdbp_header *)(prop + 1);
 978         prop->name = ((char *)prop) + tlen - 18;
 979         sprintf(prop->name, "sdb-partition-%02x", id);
 980         prop->length = len;
 981         prop->value = hdr;
 982         prop->next = NULL;
 983
 984         /* Read the datablock */
 985         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 986                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 987                        "partition %02x !\n", id);
 988                 goto failure;
 989         }
 990
 991         /* Got it, check a few things and create the property */
 992         if (hdr->id != id) {
 993                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 994                        "%02x !\n", id, hdr->id);
 995                 goto failure;
 996         }
 997         if (prom_add_property(smu->of_node, prop)) {
 998                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 999                        "property !\n", id);
1000                 goto failure;
1001         }
1002
1003         return hdr;
1004  failure:
1005         kfree(prop);
1006         return NULL;
1007 }
1008
1009 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1010  * when interruptible is 1
1011  */
1012 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1013                 unsigned int *size, int interruptible)
1014 {
1015         char pname[32];
1016         const struct smu_sdbp_header *part;
1017
1018         if (!smu)
1019                 return NULL;
1020
1021         sprintf(pname, "sdb-partition-%02x", id);
1022
1023         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1024
1025         if (interruptible) {
1026                 int rc;
1027                 rc = mutex_lock_interruptible(&smu_part_access);
1028                 if (rc)
1029                         return ERR_PTR(rc);
1030         } else
1031                 mutex_lock(&smu_part_access);
1032
1033         part = of_get_property(smu->of_node, pname, size);
1034         if (part == NULL) {
1035                 DPRINTK("trying to extract from SMU ...\n");
1036                 part = smu_create_sdb_partition(id);
1037                 if (part != NULL && size)
1038                         *size = part->len << 2;
1039         }
1040         mutex_unlock(&smu_part_access);
1041         return part;
1042 }
1043
1044 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1045 {
1046         return __smu_get_sdb_partition(id, size, 0);
1047 }
1048 EXPORT_SYMBOL(smu_get_sdb_partition);
1049
1050
1051 /*
1052  * Userland driver interface
1053  */
1054
1055
1056 static LIST_HEAD(smu_clist);
1057 static DEFINE_SPINLOCK(smu_clist_lock);
1058
1059 enum smu_file_mode {
1060         smu_file_commands,
1061         smu_file_events,
1062         smu_file_closing
1063 };
1064
1065 struct smu_private
1066 {
1067         struct list_head        list;
1068         enum smu_file_mode      mode;
1069         int                     busy;
1070         struct smu_cmd          cmd;
1071         spinlock_t              lock;
1072         wait_queue_head_t       wait;
1073         u8                      buffer[SMU_MAX_DATA];
1074 };
1075
1076
1077 static int smu_open(struct inode *inode, struct file *file)
1078 {
1079         struct smu_private *pp;
1080         unsigned long flags;
1081
1082         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1083         if (pp == 0)
1084                 return -ENOMEM;
1085         spin_lock_init(&pp->lock);
1086         pp->mode = smu_file_commands;
1087         init_waitqueue_head(&pp->wait);
1088
1089         spin_lock_irqsave(&smu_clist_lock, flags);
1090         list_add(&pp->list, &smu_clist);
1091         spin_unlock_irqrestore(&smu_clist_lock, flags);
1092         file->private_data = pp;
1093
1094         return 0;
1095 }
1096
1097
1098 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1099 {
1100         struct smu_private *pp = misc;
1101
1102         wake_up_all(&pp->wait);
1103 }
1104
1105
1106 static ssize_t smu_write(struct file *file, const char __user *buf,
1107                          size_t count, loff_t *ppos)
1108 {
1109         struct smu_private *pp = file->private_data;
1110         unsigned long flags;
1111         struct smu_user_cmd_hdr hdr;
1112         int rc = 0;
1113
1114         if (pp->busy)
1115                 return -EBUSY;
1116         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1117                 return -EFAULT;
1118         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1119                 pp->mode = smu_file_events;
1120                 return 0;
1121         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1122                 const struct smu_sdbp_header *part;
1123                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1124                 if (part == NULL)
1125                         return -EINVAL;
1126                 else if (IS_ERR(part))
1127                         return PTR_ERR(part);
1128                 return 0;
1129         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1130                 return -EINVAL;
1131         else if (pp->mode != smu_file_commands)
1132                 return -EBADFD;
1133         else if (hdr.data_len > SMU_MAX_DATA)
1134                 return -EINVAL;
1135
1136         spin_lock_irqsave(&pp->lock, flags);
1137         if (pp->busy) {
1138                 spin_unlock_irqrestore(&pp->lock, flags);
1139                 return -EBUSY;
1140         }
1141         pp->busy = 1;
1142         pp->cmd.status = 1;
1143         spin_unlock_irqrestore(&pp->lock, flags);
1144
1145         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1146                 pp->busy = 0;
1147                 return -EFAULT;
1148         }
1149
1150         pp->cmd.cmd = hdr.cmd;
1151         pp->cmd.data_len = hdr.data_len;
1152         pp->cmd.reply_len = SMU_MAX_DATA;
1153         pp->cmd.data_buf = pp->buffer;
1154         pp->cmd.reply_buf = pp->buffer;
1155         pp->cmd.done = smu_user_cmd_done;
1156         pp->cmd.misc = pp;
1157         rc = smu_queue_cmd(&pp->cmd);
1158         if (rc < 0)
1159                 return rc;
1160         return count;
1161 }
1162
1163
1164 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1165                                 char __user *buf, size_t count)
1166 {
1167         DECLARE_WAITQUEUE(wait, current);
1168         struct smu_user_reply_hdr hdr;
1169         unsigned long flags;
1170         int size, rc = 0;
1171
1172         if (!pp->busy)
1173                 return 0;
1174         if (count < sizeof(struct smu_user_reply_hdr))
1175                 return -EOVERFLOW;
1176         spin_lock_irqsave(&pp->lock, flags);
1177         if (pp->cmd.status == 1) {
1178                 if (file->f_flags & O_NONBLOCK)
1179                         return -EAGAIN;
1180                 add_wait_queue(&pp->wait, &wait);
1181                 for (;;) {
1182                         set_current_state(TASK_INTERRUPTIBLE);
1183                         rc = 0;
1184                         if (pp->cmd.status != 1)
1185                                 break;
1186                         rc = -ERESTARTSYS;
1187                         if (signal_pending(current))
1188                                 break;
1189                         spin_unlock_irqrestore(&pp->lock, flags);
1190                         schedule();
1191                         spin_lock_irqsave(&pp->lock, flags);
1192                 }
1193                 set_current_state(TASK_RUNNING);
1194                 remove_wait_queue(&pp->wait, &wait);
1195         }
1196         spin_unlock_irqrestore(&pp->lock, flags);
1197         if (rc)
1198                 return rc;
1199         if (pp->cmd.status != 0)
1200                 pp->cmd.reply_len = 0;
1201         size = sizeof(hdr) + pp->cmd.reply_len;
1202         if (count < size)
1203                 size = count;
1204         rc = size;
1205         hdr.status = pp->cmd.status;
1206         hdr.reply_len = pp->cmd.reply_len;
1207         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1208                 return -EFAULT;
1209         size -= sizeof(hdr);
1210         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1211                 return -EFAULT;
1212         pp->busy = 0;
1213
1214         return rc;
1215 }
1216
1217
1218 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1219                                char __user *buf, size_t count)
1220 {
1221         /* Not implemented */
1222         msleep_interruptible(1000);
1223         return 0;
1224 }
1225
1226
1227 static ssize_t smu_read(struct file *file, char __user *buf,
1228                         size_t count, loff_t *ppos)
1229 {
1230         struct smu_private *pp = file->private_data;
1231
1232         if (pp->mode == smu_file_commands)
1233                 return smu_read_command(file, pp, buf, count);
1234         if (pp->mode == smu_file_events)
1235                 return smu_read_events(file, pp, buf, count);
1236
1237         return -EBADFD;
1238 }
1239
1240 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1241 {
1242         struct smu_private *pp = file->private_data;
1243         unsigned int mask = 0;
1244         unsigned long flags;
1245
1246         if (pp == 0)
1247                 return 0;
1248
1249         if (pp->mode == smu_file_commands) {
1250                 poll_wait(file, &pp->wait, wait);
1251
1252                 spin_lock_irqsave(&pp->lock, flags);
1253                 if (pp->busy && pp->cmd.status != 1)
1254                         mask |= POLLIN;
1255                 spin_unlock_irqrestore(&pp->lock, flags);
1256         } if (pp->mode == smu_file_events) {
1257                 /* Not yet implemented */
1258         }
1259         return mask;
1260 }
1261
1262 static int smu_release(struct inode *inode, struct file *file)
1263 {
1264         struct smu_private *pp = file->private_data;
1265         unsigned long flags;
1266         unsigned int busy;
1267
1268         if (pp == 0)
1269                 return 0;
1270
1271         file->private_data = NULL;
1272
1273         /* Mark file as closing to avoid races with new request */
1274         spin_lock_irqsave(&pp->lock, flags);
1275         pp->mode = smu_file_closing;
1276         busy = pp->busy;
1277
1278         /* Wait for any pending request to complete */
1279         if (busy && pp->cmd.status == 1) {
1280                 DECLARE_WAITQUEUE(wait, current);
1281
1282                 add_wait_queue(&pp->wait, &wait);
1283                 for (;;) {
1284                         set_current_state(TASK_UNINTERRUPTIBLE);
1285                         if (pp->cmd.status != 1)
1286                                 break;
1287                         spin_unlock_irqrestore(&pp->lock, flags);
1288                         schedule();
1289                         spin_lock_irqsave(&pp->lock, flags);
1290                 }
1291                 set_current_state(TASK_RUNNING);
1292                 remove_wait_queue(&pp->wait, &wait);
1293         }
1294         spin_unlock_irqrestore(&pp->lock, flags);
1295
1296         spin_lock_irqsave(&smu_clist_lock, flags);
1297         list_del(&pp->list);
1298         spin_unlock_irqrestore(&smu_clist_lock, flags);
1299         kfree(pp);
1300
1301         return 0;
1302 }
1303
1304
1305 static const struct file_operations smu_device_fops = {
1306         .llseek         = no_llseek,
1307         .read           = smu_read,
1308         .write          = smu_write,
1309         .poll           = smu_fpoll,
1310         .open           = smu_open,
1311         .release        = smu_release,
1312 };
1313
1314 static struct miscdevice pmu_device = {
1315         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1316 };
1317
1318 static int smu_device_init(void)
1319 {
1320         if (!smu)
1321                 return -ENODEV;
1322         if (misc_register(&pmu_device) < 0)
1323                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1324         return 0;
1325 }
1326 device_initcall(smu_device_init);