drivers/macintosh/smu.c

   1 /*
   2  * PowerMac G5 SMU driver
   3  *
   4  * Copyright 2004 J. Mayer <l_indien@magic.fr>
   5  * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   6  *
   7  * Released under the term of the GNU GPL v2.
   8  */
   9
  10 /*
  11  * TODO:
  12  *  - maybe add timeout to commands ?
  13  *  - blocking version of time functions
  14  *  - polling version of i2c commands (including timer that works with
  15  *    interrupts off)
  16  *  - maybe avoid some data copies with i2c by directly using the smu cmd
  17  *    buffer and a lower level internal interface
  18  *  - understand SMU -> CPU events and implement reception of them via
  19  *    the userland interface
  20  */
  21
  22 #include <linux/types.h>
  23 #include <linux/kernel.h>
  24 #include <linux/device.h>
  25 #include <linux/dmapool.h>
  26 #include <linux/bootmem.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/highmem.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/rtc.h>
  32 #include <linux/completion.h>
  33 #include <linux/miscdevice.h>
  34 #include <linux/delay.h>
  35 #include <linux/poll.h>
  36 #include <linux/mutex.h>
  37 #include <linux/of_device.h>
  38 #include <linux/of_irq.h>
  39 #include <linux/of_platform.h>
  40 #include <linux/slab.h>
  41 #include <linux/memblock.h>
  42 #include <linux/sched/signal.h>
  43
  44 #include <asm/byteorder.h>
  45 #include <asm/io.h>
  46 #include <asm/prom.h>
  47 #include <asm/machdep.h>
  48 #include <asm/pmac_feature.h>
  49 #include <asm/smu.h>
  50 #include <asm/sections.h>
  51 #include <linux/uaccess.h>
  52
  53 #define VERSION "0.7"
  54 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  55
  56 #undef DEBUG_SMU
  57
  58 #ifdef DEBUG_SMU
  59 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  60 #else
  61 #define DPRINTK(fmt, args...) do { } while (0)
  62 #endif
  63
  64 /*
  65  * This is the command buffer passed to the SMU hardware
  66  */
  67 #define SMU_MAX_DATA    254
  68
  69 struct smu_cmd_buf {
  70         u8 cmd;
  71         u8 length;
  72         u8 data[SMU_MAX_DATA];
  73 };
  74
  75 struct smu_device {
  76         spinlock_t              lock;
  77         struct device_node      *of_node;
  78         struct platform_device  *of_dev;
  79         int                     doorbell;       /* doorbell gpio */
  80         u32 __iomem             *db_buf;        /* doorbell buffer */
  81         struct device_node      *db_node;
  82         unsigned int            db_irq;
  83         int                     msg;
  84         struct device_node      *msg_node;
  85         unsigned int            msg_irq;
  86         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  87         u32                     cmd_buf_abs;    /* command buffer absolute */
  88         struct list_head        cmd_list;
  89         struct smu_cmd          *cmd_cur;       /* pending command */
  90         int                     broken_nap;
  91         struct list_head        cmd_i2c_list;
  92         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  93         struct timer_list       i2c_timer;
  94 };
  95
  96 /*
  97  * I don't think there will ever be more than one SMU, so
  98  * for now, just hard code that
  99  */
 100 static DEFINE_MUTEX(smu_mutex);
 101 static struct smu_device        *smu;
 102 static DEFINE_MUTEX(smu_part_access);
 103 static int smu_irq_inited;
 104 static unsigned long smu_cmdbuf_abs;
 105
 106 static void smu_i2c_retry(unsigned long data);
 107
 108 /*
 109  * SMU driver low level stuff
 110  */
 111
 112 static void smu_start_cmd(void)
 113 {
 114         unsigned long faddr, fend;
 115         struct smu_cmd *cmd;
 116
 117         if (list_empty(&smu->cmd_list))
 118                 return;
 119
 120         /* Fetch first command in queue */
 121         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 122         smu->cmd_cur = cmd;
 123         list_del(&cmd->link);
 124
 125         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 126                 cmd->data_len);
 127         DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf);
 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)
 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         int ret = 0;
 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         /*
 486          * SMU based G5s need some memory below 2Gb. Thankfully this is
 487          * called at a time where memblock is still available.
 488          */
 489         smu_cmdbuf_abs = memblock_alloc_base(4096, 4096, 0x80000000UL);
 490         if (smu_cmdbuf_abs == 0) {
 491                 printk(KERN_ERR "SMU: Command buffer allocation failed !\n");
 492                 ret = -EINVAL;
 493                 goto fail_np;
 494         }
 495
 496         smu = alloc_bootmem(sizeof(struct smu_device));
 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 = 0;
 503         smu->msg_irq = 0;
 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 = __va(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                 ret = -ENXIO;
 515                 goto fail_bootmem;
 516         }
 517         data = of_get_property(smu->db_node, "reg", NULL);
 518         if (data == NULL) {
 519                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 520                 ret = -ENXIO;
 521                 goto fail_db_node;
 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                 ret = -ENXIO;
 556                 goto fail_msg_node;
 557         }
 558
 559         /* U3 has an issue with NAP mode when issuing SMU commands */
 560         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 561         if (smu->broken_nap)
 562                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 563
 564         sys_ctrler = SYS_CTRLER_SMU;
 565         return 0;
 566
 567 fail_msg_node:
 568         of_node_put(smu->msg_node);
 569 fail_db_node:
 570         of_node_put(smu->db_node);
 571 fail_bootmem:
 572         free_bootmem(__pa(smu), sizeof(struct smu_device));
 573         smu = NULL;
 574 fail_np:
 575         of_node_put(np);
 576         return ret;
 577 }
 578
 579
 580 static int smu_late_init(void)
 581 {
 582         if (!smu)
 583                 return 0;
 584
 585         init_timer(&smu->i2c_timer);
 586         smu->i2c_timer.function = smu_i2c_retry;
 587         smu->i2c_timer.data = (unsigned long)smu;
 588
 589         if (smu->db_node) {
 590                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 591                 if (!smu->db_irq)
 592                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 593                                smu->db_node->full_name);
 594         }
 595         if (smu->msg_node) {
 596                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 597                 if (!smu->msg_irq)
 598                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 599                                smu->msg_node->full_name);
 600         }
 601
 602         /*
 603          * Try to request the interrupts
 604          */
 605
 606         if (smu->db_irq) {
 607                 if (request_irq(smu->db_irq, smu_db_intr,
 608                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 609                         printk(KERN_WARNING "SMU: can't "
 610                                "request interrupt %d\n",
 611                                smu->db_irq);
 612                         smu->db_irq = 0;
 613                 }
 614         }
 615
 616         if (smu->msg_irq) {
 617                 if (request_irq(smu->msg_irq, smu_msg_intr,
 618                                 IRQF_SHARED, "SMU message", smu) < 0) {
 619                         printk(KERN_WARNING "SMU: can't "
 620                                "request interrupt %d\n",
 621                                smu->msg_irq);
 622                         smu->msg_irq = 0;
 623                 }
 624         }
 625
 626         smu_irq_inited = 1;
 627         return 0;
 628 }
 629 /* This has to be before arch_initcall as the low i2c stuff relies on the
 630  * above having been done before we reach arch_initcalls
 631  */
 632 core_initcall(smu_late_init);
 633
 634 /*
 635  * sysfs visibility
 636  */
 637
 638 static void smu_expose_childs(struct work_struct *unused)
 639 {
 640         struct device_node *np;
 641
 642         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 643                 if (of_device_is_compatible(np, "smu-sensors"))
 644                         of_platform_device_create(np, "smu-sensors",
 645                                                   &smu->of_dev->dev);
 646 }
 647
 648 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 649
 650 static int smu_platform_probe(struct platform_device* dev)
 651 {
 652         if (!smu)
 653                 return -ENODEV;
 654         smu->of_dev = dev;
 655
 656         /*
 657          * Ok, we are matched, now expose all i2c busses. We have to defer
 658          * that unfortunately or it would deadlock inside the device model
 659          */
 660         schedule_work(&smu_expose_childs_work);
 661
 662         return 0;
 663 }
 664
 665 static const struct of_device_id smu_platform_match[] =
 666 {
 667         {
 668                 .type           = "smu",
 669         },
 670         {},
 671 };
 672
 673 static struct platform_driver smu_of_platform_driver =
 674 {
 675         .driver = {
 676                 .name = "smu",
 677                 .of_match_table = smu_platform_match,
 678         },
 679         .probe          = smu_platform_probe,
 680 };
 681
 682 static int __init smu_init_sysfs(void)
 683 {
 684         /*
 685          * For now, we don't power manage machines with an SMU chip,
 686          * I'm a bit too far from figuring out how that works with those
 687          * new chipsets, but that will come back and bite us
 688          */
 689         platform_driver_register(&smu_of_platform_driver);
 690         return 0;
 691 }
 692
 693 device_initcall(smu_init_sysfs);
 694
 695 struct platform_device *smu_get_ofdev(void)
 696 {
 697         if (!smu)
 698                 return NULL;
 699         return smu->of_dev;
 700 }
 701
 702 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 703
 704 /*
 705  * i2c interface
 706  */
 707
 708 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 709 {
 710         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 711         void *misc = cmd->misc;
 712         unsigned long flags;
 713
 714         /* Check for read case */
 715         if (!fail && cmd->read) {
 716                 if (cmd->pdata[0] < 1)
 717                         fail = 1;
 718                 else
 719                         memcpy(cmd->info.data, &cmd->pdata[1],
 720                                cmd->info.datalen);
 721         }
 722
 723         DPRINTK("SMU: completing, success: %d\n", !fail);
 724
 725         /* Update status and mark no pending i2c command with lock
 726          * held so nobody comes in while we dequeue an eventual
 727          * pending next i2c command
 728          */
 729         spin_lock_irqsave(&smu->lock, flags);
 730         smu->cmd_i2c_cur = NULL;
 731         wmb();
 732         cmd->status = fail ? -EIO : 0;
 733
 734         /* Is there another i2c command waiting ? */
 735         if (!list_empty(&smu->cmd_i2c_list)) {
 736                 struct smu_i2c_cmd *newcmd;
 737
 738                 /* Fetch it, new current, remove from list */
 739                 newcmd = list_entry(smu->cmd_i2c_list.next,
 740                                     struct smu_i2c_cmd, link);
 741                 smu->cmd_i2c_cur = newcmd;
 742                 list_del(&cmd->link);
 743
 744                 /* Queue with low level smu */
 745                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 746                 if (smu->cmd_cur == NULL)
 747                         smu_start_cmd();
 748         }
 749         spin_unlock_irqrestore(&smu->lock, flags);
 750
 751         /* Call command completion handler if any */
 752         if (done)
 753                 done(cmd, misc);
 754
 755 }
 756
 757
 758 static void smu_i2c_retry(unsigned long data)
 759 {
 760         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 761
 762         DPRINTK("SMU: i2c failure, requeuing...\n");
 763
 764         /* requeue command simply by resetting reply_len */
 765         cmd->pdata[0] = 0xff;
 766         cmd->scmd.reply_len = sizeof(cmd->pdata);
 767         smu_queue_cmd(&cmd->scmd);
 768 }
 769
 770
 771 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 772 {
 773         struct smu_i2c_cmd      *cmd = misc;
 774         int                     fail = 0;
 775
 776         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 777                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 778
 779         /* Check for possible status */
 780         if (scmd->status < 0)
 781                 fail = 1;
 782         else if (cmd->read) {
 783                 if (cmd->stage == 0)
 784                         fail = cmd->pdata[0] != 0;
 785                 else
 786                         fail = cmd->pdata[0] >= 0x80;
 787         } else {
 788                 fail = cmd->pdata[0] != 0;
 789         }
 790
 791         /* Handle failures by requeuing command, after 5ms interval
 792          */
 793         if (fail && --cmd->retries > 0) {
 794                 DPRINTK("SMU: i2c failure, starting timer...\n");
 795                 BUG_ON(cmd != smu->cmd_i2c_cur);
 796                 if (!smu_irq_inited) {
 797                         mdelay(5);
 798                         smu_i2c_retry(0);
 799                         return;
 800                 }
 801                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 802                 return;
 803         }
 804
 805         /* If failure or stage 1, command is complete */
 806         if (fail || cmd->stage != 0) {
 807                 smu_i2c_complete_command(cmd, fail);
 808                 return;
 809         }
 810
 811         DPRINTK("SMU: going to stage 1\n");
 812
 813         /* Ok, initial command complete, now poll status */
 814         scmd->reply_buf = cmd->pdata;
 815         scmd->reply_len = sizeof(cmd->pdata);
 816         scmd->data_buf = cmd->pdata;
 817         scmd->data_len = 1;
 818         cmd->pdata[0] = 0;
 819         cmd->stage = 1;
 820         cmd->retries = 20;
 821         smu_queue_cmd(scmd);
 822 }
 823
 824
 825 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 826 {
 827         unsigned long flags;
 828
 829         if (smu == NULL)
 830                 return -ENODEV;
 831
 832         /* Fill most fields of scmd */
 833         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 834         cmd->scmd.done = smu_i2c_low_completion;
 835         cmd->scmd.misc = cmd;
 836         cmd->scmd.reply_buf = cmd->pdata;
 837         cmd->scmd.reply_len = sizeof(cmd->pdata);
 838         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 839         cmd->scmd.status = 1;
 840         cmd->stage = 0;
 841         cmd->pdata[0] = 0xff;
 842         cmd->retries = 20;
 843         cmd->status = 1;
 844
 845         /* Check transfer type, sanitize some "info" fields
 846          * based on transfer type and do more checking
 847          */
 848         cmd->info.caddr = cmd->info.devaddr;
 849         cmd->read = cmd->info.devaddr & 0x01;
 850         switch(cmd->info.type) {
 851         case SMU_I2C_TRANSFER_SIMPLE:
 852                 memset(&cmd->info.sublen, 0, 4);
 853                 break;
 854         case SMU_I2C_TRANSFER_COMBINED:
 855                 cmd->info.devaddr &= 0xfe;
 856         case SMU_I2C_TRANSFER_STDSUB:
 857                 if (cmd->info.sublen > 3)
 858                         return -EINVAL;
 859                 break;
 860         default:
 861                 return -EINVAL;
 862         }
 863
 864         /* Finish setting up command based on transfer direction
 865          */
 866         if (cmd->read) {
 867                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 868                         return -EINVAL;
 869                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 870                 cmd->scmd.data_len = 9;
 871         } else {
 872                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 873                         return -EINVAL;
 874                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 875         }
 876
 877         DPRINTK("SMU: i2c enqueuing command\n");
 878         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 879                 cmd->read ? "read" : "write", cmd->info.datalen,
 880                 cmd->info.bus, cmd->info.caddr,
 881                 cmd->info.subaddr[0], cmd->info.type);
 882
 883
 884         /* Enqueue command in i2c list, and if empty, enqueue also in
 885          * main command list
 886          */
 887         spin_lock_irqsave(&smu->lock, flags);
 888         if (smu->cmd_i2c_cur == NULL) {
 889                 smu->cmd_i2c_cur = cmd;
 890                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 891                 if (smu->cmd_cur == NULL)
 892                         smu_start_cmd();
 893         } else
 894                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 895         spin_unlock_irqrestore(&smu->lock, flags);
 896
 897         return 0;
 898 }
 899
 900 /*
 901  * Handling of "partitions"
 902  */
 903
 904 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 905 {
 906         DECLARE_COMPLETION_ONSTACK(comp);
 907         unsigned int chunk;
 908         struct smu_cmd cmd;
 909         int rc;
 910         u8 params[8];
 911
 912         /* We currently use a chunk size of 0xe. We could check the
 913          * SMU firmware version and use bigger sizes though
 914          */
 915         chunk = 0xe;
 916
 917         while (len) {
 918                 unsigned int clen = min(len, chunk);
 919
 920                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 921                 cmd.data_len = 7;
 922                 cmd.data_buf = params;
 923                 cmd.reply_len = chunk;
 924                 cmd.reply_buf = dest;
 925                 cmd.done = smu_done_complete;
 926                 cmd.misc = &comp;
 927                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 928                 params[1] = 0x4;
 929                 *((u32 *)&params[2]) = addr;
 930                 params[6] = clen;
 931
 932                 rc = smu_queue_cmd(&cmd);
 933                 if (rc)
 934                         return rc;
 935                 wait_for_completion(&comp);
 936                 if (cmd.status != 0)
 937                         return rc;
 938                 if (cmd.reply_len != clen) {
 939                         printk(KERN_DEBUG "SMU: short read in "
 940                                "smu_read_datablock, got: %d, want: %d\n",
 941                                cmd.reply_len, clen);
 942                         return -EIO;
 943                 }
 944                 len -= clen;
 945                 addr += clen;
 946                 dest += clen;
 947         }
 948         return 0;
 949 }
 950
 951 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 952 {
 953         DECLARE_COMPLETION_ONSTACK(comp);
 954         struct smu_simple_cmd cmd;
 955         unsigned int addr, len, tlen;
 956         struct smu_sdbp_header *hdr;
 957         struct property *prop;
 958
 959         /* First query the partition info */
 960         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 961         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 962                          smu_done_complete, &comp,
 963                          SMU_CMD_PARTITION_LATEST, id);
 964         wait_for_completion(&comp);
 965         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 966                 cmd.cmd.status, cmd.cmd.reply_len);
 967
 968         /* Partition doesn't exist (or other error) */
 969         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 970                 return NULL;
 971
 972         /* Fetch address and length from reply */
 973         addr = *((u16 *)cmd.buffer);
 974         len = cmd.buffer[3] << 2;
 975         /* Calucluate total length to allocate, including the 17 bytes
 976          * for "sdb-partition-XX" that we append at the end of the buffer
 977          */
 978         tlen = sizeof(struct property) + len + 18;
 979
 980         prop = kzalloc(tlen, GFP_KERNEL);
 981         if (prop == NULL)
 982                 return NULL;
 983         hdr = (struct smu_sdbp_header *)(prop + 1);
 984         prop->name = ((char *)prop) + tlen - 18;
 985         sprintf(prop->name, "sdb-partition-%02x", id);
 986         prop->length = len;
 987         prop->value = hdr;
 988         prop->next = NULL;
 989
 990         /* Read the datablock */
 991         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 992                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 993                        "partition %02x !\n", id);
 994                 goto failure;
 995         }
 996
 997         /* Got it, check a few things and create the property */
 998         if (hdr->id != id) {
 999                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
1000                        "%02x !\n", id, hdr->id);
1001                 goto failure;
1002         }
1003         if (of_add_property(smu->of_node, prop)) {
1004                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1005                        "property !\n", id);
1006                 goto failure;
1007         }
1008
1009         return hdr;
1010  failure:
1011         kfree(prop);
1012         return NULL;
1013 }
1014
1015 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1016  * when interruptible is 1
1017  */
1018 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1019                 unsigned int *size, int interruptible)
1020 {
1021         char pname[32];
1022         const struct smu_sdbp_header *part;
1023
1024         if (!smu)
1025                 return NULL;
1026
1027         sprintf(pname, "sdb-partition-%02x", id);
1028
1029         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1030
1031         if (interruptible) {
1032                 int rc;
1033                 rc = mutex_lock_interruptible(&smu_part_access);
1034                 if (rc)
1035                         return ERR_PTR(rc);
1036         } else
1037                 mutex_lock(&smu_part_access);
1038
1039         part = of_get_property(smu->of_node, pname, size);
1040         if (part == NULL) {
1041                 DPRINTK("trying to extract from SMU ...\n");
1042                 part = smu_create_sdb_partition(id);
1043                 if (part != NULL && size)
1044                         *size = part->len << 2;
1045         }
1046         mutex_unlock(&smu_part_access);
1047         return part;
1048 }
1049
1050 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1051 {
1052         return __smu_get_sdb_partition(id, size, 0);
1053 }
1054 EXPORT_SYMBOL(smu_get_sdb_partition);
1055
1056
1057 /*
1058  * Userland driver interface
1059  */
1060
1061
1062 static LIST_HEAD(smu_clist);
1063 static DEFINE_SPINLOCK(smu_clist_lock);
1064
1065 enum smu_file_mode {
1066         smu_file_commands,
1067         smu_file_events,
1068         smu_file_closing
1069 };
1070
1071 struct smu_private
1072 {
1073         struct list_head        list;
1074         enum smu_file_mode      mode;
1075         int                     busy;
1076         struct smu_cmd          cmd;
1077         spinlock_t              lock;
1078         wait_queue_head_t       wait;
1079         u8                      buffer[SMU_MAX_DATA];
1080 };
1081
1082
1083 static int smu_open(struct inode *inode, struct file *file)
1084 {
1085         struct smu_private *pp;
1086         unsigned long flags;
1087
1088         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1089         if (pp == 0)
1090                 return -ENOMEM;
1091         spin_lock_init(&pp->lock);
1092         pp->mode = smu_file_commands;
1093         init_waitqueue_head(&pp->wait);
1094
1095         mutex_lock(&smu_mutex);
1096         spin_lock_irqsave(&smu_clist_lock, flags);
1097         list_add(&pp->list, &smu_clist);
1098         spin_unlock_irqrestore(&smu_clist_lock, flags);
1099         file->private_data = pp;
1100         mutex_unlock(&smu_mutex);
1101
1102         return 0;
1103 }
1104
1105
1106 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1107 {
1108         struct smu_private *pp = misc;
1109
1110         wake_up_all(&pp->wait);
1111 }
1112
1113
1114 static ssize_t smu_write(struct file *file, const char __user *buf,
1115                          size_t count, loff_t *ppos)
1116 {
1117         struct smu_private *pp = file->private_data;
1118         unsigned long flags;
1119         struct smu_user_cmd_hdr hdr;
1120         int rc = 0;
1121
1122         if (pp->busy)
1123                 return -EBUSY;
1124         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1125                 return -EFAULT;
1126         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1127                 pp->mode = smu_file_events;
1128                 return 0;
1129         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1130                 const struct smu_sdbp_header *part;
1131                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1132                 if (part == NULL)
1133                         return -EINVAL;
1134                 else if (IS_ERR(part))
1135                         return PTR_ERR(part);
1136                 return 0;
1137         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1138                 return -EINVAL;
1139         else if (pp->mode != smu_file_commands)
1140                 return -EBADFD;
1141         else if (hdr.data_len > SMU_MAX_DATA)
1142                 return -EINVAL;
1143
1144         spin_lock_irqsave(&pp->lock, flags);
1145         if (pp->busy) {
1146                 spin_unlock_irqrestore(&pp->lock, flags);
1147                 return -EBUSY;
1148         }
1149         pp->busy = 1;
1150         pp->cmd.status = 1;
1151         spin_unlock_irqrestore(&pp->lock, flags);
1152
1153         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1154                 pp->busy = 0;
1155                 return -EFAULT;
1156         }
1157
1158         pp->cmd.cmd = hdr.cmd;
1159         pp->cmd.data_len = hdr.data_len;
1160         pp->cmd.reply_len = SMU_MAX_DATA;
1161         pp->cmd.data_buf = pp->buffer;
1162         pp->cmd.reply_buf = pp->buffer;
1163         pp->cmd.done = smu_user_cmd_done;
1164         pp->cmd.misc = pp;
1165         rc = smu_queue_cmd(&pp->cmd);
1166         if (rc < 0)
1167                 return rc;
1168         return count;
1169 }
1170
1171
1172 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1173                                 char __user *buf, size_t count)
1174 {
1175         DECLARE_WAITQUEUE(wait, current);
1176         struct smu_user_reply_hdr hdr;
1177         unsigned long flags;
1178         int size, rc = 0;
1179
1180         if (!pp->busy)
1181                 return 0;
1182         if (count < sizeof(struct smu_user_reply_hdr))
1183                 return -EOVERFLOW;
1184         spin_lock_irqsave(&pp->lock, flags);
1185         if (pp->cmd.status == 1) {
1186                 if (file->f_flags & O_NONBLOCK) {
1187                         spin_unlock_irqrestore(&pp->lock, flags);
1188                         return -EAGAIN;
1189                 }
1190                 add_wait_queue(&pp->wait, &wait);
1191                 for (;;) {
1192                         set_current_state(TASK_INTERRUPTIBLE);
1193                         rc = 0;
1194                         if (pp->cmd.status != 1)
1195                                 break;
1196                         rc = -ERESTARTSYS;
1197                         if (signal_pending(current))
1198                                 break;
1199                         spin_unlock_irqrestore(&pp->lock, flags);
1200                         schedule();
1201                         spin_lock_irqsave(&pp->lock, flags);
1202                 }
1203                 set_current_state(TASK_RUNNING);
1204                 remove_wait_queue(&pp->wait, &wait);
1205         }
1206         spin_unlock_irqrestore(&pp->lock, flags);
1207         if (rc)
1208                 return rc;
1209         if (pp->cmd.status != 0)
1210                 pp->cmd.reply_len = 0;
1211         size = sizeof(hdr) + pp->cmd.reply_len;
1212         if (count < size)
1213                 size = count;
1214         rc = size;
1215         hdr.status = pp->cmd.status;
1216         hdr.reply_len = pp->cmd.reply_len;
1217         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1218                 return -EFAULT;
1219         size -= sizeof(hdr);
1220         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1221                 return -EFAULT;
1222         pp->busy = 0;
1223
1224         return rc;
1225 }
1226
1227
1228 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1229                                char __user *buf, size_t count)
1230 {
1231         /* Not implemented */
1232         msleep_interruptible(1000);
1233         return 0;
1234 }
1235
1236
1237 static ssize_t smu_read(struct file *file, char __user *buf,
1238                         size_t count, loff_t *ppos)
1239 {
1240         struct smu_private *pp = file->private_data;
1241
1242         if (pp->mode == smu_file_commands)
1243                 return smu_read_command(file, pp, buf, count);
1244         if (pp->mode == smu_file_events)
1245                 return smu_read_events(file, pp, buf, count);
1246
1247         return -EBADFD;
1248 }
1249
1250 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1251 {
1252         struct smu_private *pp = file->private_data;
1253         unsigned int mask = 0;
1254         unsigned long flags;
1255
1256         if (pp == 0)
1257                 return 0;
1258
1259         if (pp->mode == smu_file_commands) {
1260                 poll_wait(file, &pp->wait, wait);
1261
1262                 spin_lock_irqsave(&pp->lock, flags);
1263                 if (pp->busy && pp->cmd.status != 1)
1264                         mask |= POLLIN;
1265                 spin_unlock_irqrestore(&pp->lock, flags);
1266         }
1267         if (pp->mode == smu_file_events) {
1268                 /* Not yet implemented */
1269         }
1270         return mask;
1271 }
1272
1273 static int smu_release(struct inode *inode, struct file *file)
1274 {
1275         struct smu_private *pp = file->private_data;
1276         unsigned long flags;
1277         unsigned int busy;
1278
1279         if (pp == 0)
1280                 return 0;
1281
1282         file->private_data = NULL;
1283
1284         /* Mark file as closing to avoid races with new request */
1285         spin_lock_irqsave(&pp->lock, flags);
1286         pp->mode = smu_file_closing;
1287         busy = pp->busy;
1288
1289         /* Wait for any pending request to complete */
1290         if (busy && pp->cmd.status == 1) {
1291                 DECLARE_WAITQUEUE(wait, current);
1292
1293                 add_wait_queue(&pp->wait, &wait);
1294                 for (;;) {
1295                         set_current_state(TASK_UNINTERRUPTIBLE);
1296                         if (pp->cmd.status != 1)
1297                                 break;
1298                         spin_unlock_irqrestore(&pp->lock, flags);
1299                         schedule();
1300                         spin_lock_irqsave(&pp->lock, flags);
1301                 }
1302                 set_current_state(TASK_RUNNING);
1303                 remove_wait_queue(&pp->wait, &wait);
1304         }
1305         spin_unlock_irqrestore(&pp->lock, flags);
1306
1307         spin_lock_irqsave(&smu_clist_lock, flags);
1308         list_del(&pp->list);
1309         spin_unlock_irqrestore(&smu_clist_lock, flags);
1310         kfree(pp);
1311
1312         return 0;
1313 }
1314
1315
1316 static const struct file_operations smu_device_fops = {
1317         .llseek         = no_llseek,
1318         .read           = smu_read,
1319         .write          = smu_write,
1320         .poll           = smu_fpoll,
1321         .open           = smu_open,
1322         .release        = smu_release,
1323 };
1324
1325 static struct miscdevice pmu_device = {
1326         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1327 };
1328
1329 static int smu_device_init(void)
1330 {
1331         if (!smu)
1332                 return -ENODEV;
1333         if (misc_register(&pmu_device) < 0)
1334                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1335         return 0;
1336 }
1337 device_initcall(smu_device_init);