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 #include <linux/of_device.h>
  39 #include <linux/of_platform.h>
  40
  41 #include <asm/byteorder.h>
  42 #include <asm/io.h>
  43 #include <asm/prom.h>
  44 #include <asm/machdep.h>
  45 #include <asm/pmac_feature.h>
  46 #include <asm/smu.h>
  47 #include <asm/sections.h>
  48 #include <asm/abs_addr.h>
  49 #include <asm/uaccess.h>
  50
  51 #define VERSION "0.7"
  52 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  53
  54 #undef DEBUG_SMU
  55
  56 #ifdef DEBUG_SMU
  57 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  58 #else
  59 #define DPRINTK(fmt, args...) do { } while (0)
  60 #endif
  61
  62 /*
  63  * This is the command buffer passed to the SMU hardware
  64  */
  65 #define SMU_MAX_DATA    254
  66
  67 struct smu_cmd_buf {
  68         u8 cmd;
  69         u8 length;
  70         u8 data[SMU_MAX_DATA];
  71 };
  72
  73 struct smu_device {
  74         spinlock_t              lock;
  75         struct device_node      *of_node;
  76         struct 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         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         if (smu_cmdbuf_abs == 0) {
 486                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 487                 ret = -EINVAL;
 488                 goto fail_np;
 489         }
 490
 491         smu = alloc_bootmem(sizeof(struct smu_device));
 492
 493         spin_lock_init(&smu->lock);
 494         INIT_LIST_HEAD(&smu->cmd_list);
 495         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 496         smu->of_node = np;
 497         smu->db_irq = NO_IRQ;
 498         smu->msg_irq = NO_IRQ;
 499
 500         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 501          * 32 bits value safely
 502          */
 503         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 504         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 505
 506         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 507         if (smu->db_node == NULL) {
 508                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 509                 ret = -ENXIO;
 510                 goto fail_bootmem;
 511         }
 512         data = of_get_property(smu->db_node, "reg", NULL);
 513         if (data == NULL) {
 514                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 515                 ret = -ENXIO;
 516                 goto fail_db_node;
 517         }
 518
 519         /* Current setup has one doorbell GPIO that does both doorbell
 520          * and ack. GPIOs are at 0x50, best would be to find that out
 521          * in the device-tree though.
 522          */
 523         smu->doorbell = *data;
 524         if (smu->doorbell < 0x50)
 525                 smu->doorbell += 0x50;
 526
 527         /* Now look for the smu-interrupt GPIO */
 528         do {
 529                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 530                 if (smu->msg_node == NULL)
 531                         break;
 532                 data = of_get_property(smu->msg_node, "reg", NULL);
 533                 if (data == NULL) {
 534                         of_node_put(smu->msg_node);
 535                         smu->msg_node = NULL;
 536                         break;
 537                 }
 538                 smu->msg = *data;
 539                 if (smu->msg < 0x50)
 540                         smu->msg += 0x50;
 541         } while(0);
 542
 543         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 544          * device-tree entry giving the address. Best would probably to use
 545          * an offset for K2 base though, but let's do it that way for now.
 546          */
 547         smu->db_buf = ioremap(0x8000860c, 0x1000);
 548         if (smu->db_buf == NULL) {
 549                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 550                 ret = -ENXIO;
 551                 goto fail_msg_node;
 552         }
 553
 554         /* U3 has an issue with NAP mode when issuing SMU commands */
 555         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 556         if (smu->broken_nap)
 557                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 558
 559         sys_ctrler = SYS_CTRLER_SMU;
 560         return 0;
 561
 562 fail_msg_node:
 563         if (smu->msg_node)
 564                 of_node_put(smu->msg_node);
 565 fail_db_node:
 566         of_node_put(smu->db_node);
 567 fail_bootmem:
 568         free_bootmem((unsigned long)smu, sizeof(struct smu_device));
 569         smu = NULL;
 570 fail_np:
 571         of_node_put(np);
 572         return ret;
 573 }
 574
 575
 576 static int smu_late_init(void)
 577 {
 578         if (!smu)
 579                 return 0;
 580
 581         init_timer(&smu->i2c_timer);
 582         smu->i2c_timer.function = smu_i2c_retry;
 583         smu->i2c_timer.data = (unsigned long)smu;
 584
 585         if (smu->db_node) {
 586                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 587                 if (smu->db_irq == NO_IRQ)
 588                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 589                                smu->db_node->full_name);
 590         }
 591         if (smu->msg_node) {
 592                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 593                 if (smu->msg_irq == NO_IRQ)
 594                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 595                                smu->msg_node->full_name);
 596         }
 597
 598         /*
 599          * Try to request the interrupts
 600          */
 601
 602         if (smu->db_irq != NO_IRQ) {
 603                 if (request_irq(smu->db_irq, smu_db_intr,
 604                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 605                         printk(KERN_WARNING "SMU: can't "
 606                                "request interrupt %d\n",
 607                                smu->db_irq);
 608                         smu->db_irq = NO_IRQ;
 609                 }
 610         }
 611
 612         if (smu->msg_irq != NO_IRQ) {
 613                 if (request_irq(smu->msg_irq, smu_msg_intr,
 614                                 IRQF_SHARED, "SMU message", smu) < 0) {
 615                         printk(KERN_WARNING "SMU: can't "
 616                                "request interrupt %d\n",
 617                                smu->msg_irq);
 618                         smu->msg_irq = NO_IRQ;
 619                 }
 620         }
 621
 622         smu_irq_inited = 1;
 623         return 0;
 624 }
 625 /* This has to be before arch_initcall as the low i2c stuff relies on the
 626  * above having been done before we reach arch_initcalls
 627  */
 628 core_initcall(smu_late_init);
 629
 630 /*
 631  * sysfs visibility
 632  */
 633
 634 static void smu_expose_childs(struct work_struct *unused)
 635 {
 636         struct device_node *np;
 637
 638         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 639                 if (of_device_is_compatible(np, "smu-sensors"))
 640                         of_platform_device_create(np, "smu-sensors",
 641                                                   &smu->of_dev->dev);
 642 }
 643
 644 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 645
 646 static int smu_platform_probe(struct of_device* dev,
 647                               const struct of_device_id *match)
 648 {
 649         if (!smu)
 650                 return -ENODEV;
 651         smu->of_dev = dev;
 652
 653         /*
 654          * Ok, we are matched, now expose all i2c busses. We have to defer
 655          * that unfortunately or it would deadlock inside the device model
 656          */
 657         schedule_work(&smu_expose_childs_work);
 658
 659         return 0;
 660 }
 661
 662 static struct of_device_id smu_platform_match[] =
 663 {
 664         {
 665                 .type           = "smu",
 666         },
 667         {},
 668 };
 669
 670 static struct of_platform_driver smu_of_platform_driver =
 671 {
 672         .name           = "smu",
 673         .match_table    = smu_platform_match,
 674         .probe          = smu_platform_probe,
 675 };
 676
 677 static int __init smu_init_sysfs(void)
 678 {
 679         /*
 680          * Due to sysfs bogosity, a sysdev is not a real device, so
 681          * we should in fact create both if we want sysdev semantics
 682          * for power management.
 683          * For now, we don't power manage machines with an SMU chip,
 684          * I'm a bit too far from figuring out how that works with those
 685          * new chipsets, but that will come back and bite us
 686          */
 687         of_register_platform_driver(&smu_of_platform_driver);
 688         return 0;
 689 }
 690
 691 device_initcall(smu_init_sysfs);
 692
 693 struct of_device *smu_get_ofdev(void)
 694 {
 695         if (!smu)
 696                 return NULL;
 697         return smu->of_dev;
 698 }
 699
 700 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 701
 702 /*
 703  * i2c interface
 704  */
 705
 706 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 707 {
 708         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 709         void *misc = cmd->misc;
 710         unsigned long flags;
 711
 712         /* Check for read case */
 713         if (!fail && cmd->read) {
 714                 if (cmd->pdata[0] < 1)
 715                         fail = 1;
 716                 else
 717                         memcpy(cmd->info.data, &cmd->pdata[1],
 718                                cmd->info.datalen);
 719         }
 720
 721         DPRINTK("SMU: completing, success: %d\n", !fail);
 722
 723         /* Update status and mark no pending i2c command with lock
 724          * held so nobody comes in while we dequeue an eventual
 725          * pending next i2c command
 726          */
 727         spin_lock_irqsave(&smu->lock, flags);
 728         smu->cmd_i2c_cur = NULL;
 729         wmb();
 730         cmd->status = fail ? -EIO : 0;
 731
 732         /* Is there another i2c command waiting ? */
 733         if (!list_empty(&smu->cmd_i2c_list)) {
 734                 struct smu_i2c_cmd *newcmd;
 735
 736                 /* Fetch it, new current, remove from list */
 737                 newcmd = list_entry(smu->cmd_i2c_list.next,
 738                                     struct smu_i2c_cmd, link);
 739                 smu->cmd_i2c_cur = newcmd;
 740                 list_del(&cmd->link);
 741
 742                 /* Queue with low level smu */
 743                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 744                 if (smu->cmd_cur == NULL)
 745                         smu_start_cmd();
 746         }
 747         spin_unlock_irqrestore(&smu->lock, flags);
 748
 749         /* Call command completion handler if any */
 750         if (done)
 751                 done(cmd, misc);
 752
 753 }
 754
 755
 756 static void smu_i2c_retry(unsigned long data)
 757 {
 758         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 759
 760         DPRINTK("SMU: i2c failure, requeuing...\n");
 761
 762         /* requeue command simply by resetting reply_len */
 763         cmd->pdata[0] = 0xff;
 764         cmd->scmd.reply_len = sizeof(cmd->pdata);
 765         smu_queue_cmd(&cmd->scmd);
 766 }
 767
 768
 769 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 770 {
 771         struct smu_i2c_cmd      *cmd = misc;
 772         int                     fail = 0;
 773
 774         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 775                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 776
 777         /* Check for possible status */
 778         if (scmd->status < 0)
 779                 fail = 1;
 780         else if (cmd->read) {
 781                 if (cmd->stage == 0)
 782                         fail = cmd->pdata[0] != 0;
 783                 else
 784                         fail = cmd->pdata[0] >= 0x80;
 785         } else {
 786                 fail = cmd->pdata[0] != 0;
 787         }
 788
 789         /* Handle failures by requeuing command, after 5ms interval
 790          */
 791         if (fail && --cmd->retries > 0) {
 792                 DPRINTK("SMU: i2c failure, starting timer...\n");
 793                 BUG_ON(cmd != smu->cmd_i2c_cur);
 794                 if (!smu_irq_inited) {
 795                         mdelay(5);
 796                         smu_i2c_retry(0);
 797                         return;
 798                 }
 799                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 800                 return;
 801         }
 802
 803         /* If failure or stage 1, command is complete */
 804         if (fail || cmd->stage != 0) {
 805                 smu_i2c_complete_command(cmd, fail);
 806                 return;
 807         }
 808
 809         DPRINTK("SMU: going to stage 1\n");
 810
 811         /* Ok, initial command complete, now poll status */
 812         scmd->reply_buf = cmd->pdata;
 813         scmd->reply_len = sizeof(cmd->pdata);
 814         scmd->data_buf = cmd->pdata;
 815         scmd->data_len = 1;
 816         cmd->pdata[0] = 0;
 817         cmd->stage = 1;
 818         cmd->retries = 20;
 819         smu_queue_cmd(scmd);
 820 }
 821
 822
 823 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 824 {
 825         unsigned long flags;
 826
 827         if (smu == NULL)
 828                 return -ENODEV;
 829
 830         /* Fill most fields of scmd */
 831         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 832         cmd->scmd.done = smu_i2c_low_completion;
 833         cmd->scmd.misc = cmd;
 834         cmd->scmd.reply_buf = cmd->pdata;
 835         cmd->scmd.reply_len = sizeof(cmd->pdata);
 836         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 837         cmd->scmd.status = 1;
 838         cmd->stage = 0;
 839         cmd->pdata[0] = 0xff;
 840         cmd->retries = 20;
 841         cmd->status = 1;
 842
 843         /* Check transfer type, sanitize some "info" fields
 844          * based on transfer type and do more checking
 845          */
 846         cmd->info.caddr = cmd->info.devaddr;
 847         cmd->read = cmd->info.devaddr & 0x01;
 848         switch(cmd->info.type) {
 849         case SMU_I2C_TRANSFER_SIMPLE:
 850                 memset(&cmd->info.sublen, 0, 4);
 851                 break;
 852         case SMU_I2C_TRANSFER_COMBINED:
 853                 cmd->info.devaddr &= 0xfe;
 854         case SMU_I2C_TRANSFER_STDSUB:
 855                 if (cmd->info.sublen > 3)
 856                         return -EINVAL;
 857                 break;
 858         default:
 859                 return -EINVAL;
 860         }
 861
 862         /* Finish setting up command based on transfer direction
 863          */
 864         if (cmd->read) {
 865                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 866                         return -EINVAL;
 867                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 868                 cmd->scmd.data_len = 9;
 869         } else {
 870                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 871                         return -EINVAL;
 872                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 873         }
 874
 875         DPRINTK("SMU: i2c enqueuing command\n");
 876         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 877                 cmd->read ? "read" : "write", cmd->info.datalen,
 878                 cmd->info.bus, cmd->info.caddr,
 879                 cmd->info.subaddr[0], cmd->info.type);
 880
 881
 882         /* Enqueue command in i2c list, and if empty, enqueue also in
 883          * main command list
 884          */
 885         spin_lock_irqsave(&smu->lock, flags);
 886         if (smu->cmd_i2c_cur == NULL) {
 887                 smu->cmd_i2c_cur = cmd;
 888                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 889                 if (smu->cmd_cur == NULL)
 890                         smu_start_cmd();
 891         } else
 892                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 893         spin_unlock_irqrestore(&smu->lock, flags);
 894
 895         return 0;
 896 }
 897
 898 /*
 899  * Handling of "partitions"
 900  */
 901
 902 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 903 {
 904         DECLARE_COMPLETION_ONSTACK(comp);
 905         unsigned int chunk;
 906         struct smu_cmd cmd;
 907         int rc;
 908         u8 params[8];
 909
 910         /* We currently use a chunk size of 0xe. We could check the
 911          * SMU firmware version and use bigger sizes though
 912          */
 913         chunk = 0xe;
 914
 915         while (len) {
 916                 unsigned int clen = min(len, chunk);
 917
 918                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 919                 cmd.data_len = 7;
 920                 cmd.data_buf = params;
 921                 cmd.reply_len = chunk;
 922                 cmd.reply_buf = dest;
 923                 cmd.done = smu_done_complete;
 924                 cmd.misc = &comp;
 925                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 926                 params[1] = 0x4;
 927                 *((u32 *)&params[2]) = addr;
 928                 params[6] = clen;
 929
 930                 rc = smu_queue_cmd(&cmd);
 931                 if (rc)
 932                         return rc;
 933                 wait_for_completion(&comp);
 934                 if (cmd.status != 0)
 935                         return rc;
 936                 if (cmd.reply_len != clen) {
 937                         printk(KERN_DEBUG "SMU: short read in "
 938                                "smu_read_datablock, got: %d, want: %d\n",
 939                                cmd.reply_len, clen);
 940                         return -EIO;
 941                 }
 942                 len -= clen;
 943                 addr += clen;
 944                 dest += clen;
 945         }
 946         return 0;
 947 }
 948
 949 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 950 {
 951         DECLARE_COMPLETION_ONSTACK(comp);
 952         struct smu_simple_cmd cmd;
 953         unsigned int addr, len, tlen;
 954         struct smu_sdbp_header *hdr;
 955         struct property *prop;
 956
 957         /* First query the partition info */
 958         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 959         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 960                          smu_done_complete, &comp,
 961                          SMU_CMD_PARTITION_LATEST, id);
 962         wait_for_completion(&comp);
 963         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 964                 cmd.cmd.status, cmd.cmd.reply_len);
 965
 966         /* Partition doesn't exist (or other error) */
 967         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 968                 return NULL;
 969
 970         /* Fetch address and length from reply */
 971         addr = *((u16 *)cmd.buffer);
 972         len = cmd.buffer[3] << 2;
 973         /* Calucluate total length to allocate, including the 17 bytes
 974          * for "sdb-partition-XX" that we append at the end of the buffer
 975          */
 976         tlen = sizeof(struct property) + len + 18;
 977
 978         prop = kzalloc(tlen, GFP_KERNEL);
 979         if (prop == NULL)
 980                 return NULL;
 981         hdr = (struct smu_sdbp_header *)(prop + 1);
 982         prop->name = ((char *)prop) + tlen - 18;
 983         sprintf(prop->name, "sdb-partition-%02x", id);
 984         prop->length = len;
 985         prop->value = hdr;
 986         prop->next = NULL;
 987
 988         /* Read the datablock */
 989         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 990                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 991                        "partition %02x !\n", id);
 992                 goto failure;
 993         }
 994
 995         /* Got it, check a few things and create the property */
 996         if (hdr->id != id) {
 997                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 998                        "%02x !\n", id, hdr->id);
 999                 goto failure;
1000         }
1001         if (prom_add_property(smu->of_node, prop)) {
1002                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1003                        "property !\n", id);
1004                 goto failure;
1005         }
1006
1007         return hdr;
1008  failure:
1009         kfree(prop);
1010         return NULL;
1011 }
1012
1013 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1014  * when interruptible is 1
1015  */
1016 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1017                 unsigned int *size, int interruptible)
1018 {
1019         char pname[32];
1020         const struct smu_sdbp_header *part;
1021
1022         if (!smu)
1023                 return NULL;
1024
1025         sprintf(pname, "sdb-partition-%02x", id);
1026
1027         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1028
1029         if (interruptible) {
1030                 int rc;
1031                 rc = mutex_lock_interruptible(&smu_part_access);
1032                 if (rc)
1033                         return ERR_PTR(rc);
1034         } else
1035                 mutex_lock(&smu_part_access);
1036
1037         part = of_get_property(smu->of_node, pname, size);
1038         if (part == NULL) {
1039                 DPRINTK("trying to extract from SMU ...\n");
1040                 part = smu_create_sdb_partition(id);
1041                 if (part != NULL && size)
1042                         *size = part->len << 2;
1043         }
1044         mutex_unlock(&smu_part_access);
1045         return part;
1046 }
1047
1048 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1049 {
1050         return __smu_get_sdb_partition(id, size, 0);
1051 }
1052 EXPORT_SYMBOL(smu_get_sdb_partition);
1053
1054
1055 /*
1056  * Userland driver interface
1057  */
1058
1059
1060 static LIST_HEAD(smu_clist);
1061 static DEFINE_SPINLOCK(smu_clist_lock);
1062
1063 enum smu_file_mode {
1064         smu_file_commands,
1065         smu_file_events,
1066         smu_file_closing
1067 };
1068
1069 struct smu_private
1070 {
1071         struct list_head        list;
1072         enum smu_file_mode      mode;
1073         int                     busy;
1074         struct smu_cmd          cmd;
1075         spinlock_t              lock;
1076         wait_queue_head_t       wait;
1077         u8                      buffer[SMU_MAX_DATA];
1078 };
1079
1080
1081 static int smu_open(struct inode *inode, struct file *file)
1082 {
1083         struct smu_private *pp;
1084         unsigned long flags;
1085
1086         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1087         if (pp == 0)
1088                 return -ENOMEM;
1089         spin_lock_init(&pp->lock);
1090         pp->mode = smu_file_commands;
1091         init_waitqueue_head(&pp->wait);
1092
1093         spin_lock_irqsave(&smu_clist_lock, flags);
1094         list_add(&pp->list, &smu_clist);
1095         spin_unlock_irqrestore(&smu_clist_lock, flags);
1096         file->private_data = pp;
1097
1098         return 0;
1099 }
1100
1101
1102 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1103 {
1104         struct smu_private *pp = misc;
1105
1106         wake_up_all(&pp->wait);
1107 }
1108
1109
1110 static ssize_t smu_write(struct file *file, const char __user *buf,
1111                          size_t count, loff_t *ppos)
1112 {
1113         struct smu_private *pp = file->private_data;
1114         unsigned long flags;
1115         struct smu_user_cmd_hdr hdr;
1116         int rc = 0;
1117
1118         if (pp->busy)
1119                 return -EBUSY;
1120         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1121                 return -EFAULT;
1122         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1123                 pp->mode = smu_file_events;
1124                 return 0;
1125         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1126                 const struct smu_sdbp_header *part;
1127                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1128                 if (part == NULL)
1129                         return -EINVAL;
1130                 else if (IS_ERR(part))
1131                         return PTR_ERR(part);
1132                 return 0;
1133         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1134                 return -EINVAL;
1135         else if (pp->mode != smu_file_commands)
1136                 return -EBADFD;
1137         else if (hdr.data_len > SMU_MAX_DATA)
1138                 return -EINVAL;
1139
1140         spin_lock_irqsave(&pp->lock, flags);
1141         if (pp->busy) {
1142                 spin_unlock_irqrestore(&pp->lock, flags);
1143                 return -EBUSY;
1144         }
1145         pp->busy = 1;
1146         pp->cmd.status = 1;
1147         spin_unlock_irqrestore(&pp->lock, flags);
1148
1149         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1150                 pp->busy = 0;
1151                 return -EFAULT;
1152         }
1153
1154         pp->cmd.cmd = hdr.cmd;
1155         pp->cmd.data_len = hdr.data_len;
1156         pp->cmd.reply_len = SMU_MAX_DATA;
1157         pp->cmd.data_buf = pp->buffer;
1158         pp->cmd.reply_buf = pp->buffer;
1159         pp->cmd.done = smu_user_cmd_done;
1160         pp->cmd.misc = pp;
1161         rc = smu_queue_cmd(&pp->cmd);
1162         if (rc < 0)
1163                 return rc;
1164         return count;
1165 }
1166
1167
1168 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1169                                 char __user *buf, size_t count)
1170 {
1171         DECLARE_WAITQUEUE(wait, current);
1172         struct smu_user_reply_hdr hdr;
1173         unsigned long flags;
1174         int size, rc = 0;
1175
1176         if (!pp->busy)
1177                 return 0;
1178         if (count < sizeof(struct smu_user_reply_hdr))
1179                 return -EOVERFLOW;
1180         spin_lock_irqsave(&pp->lock, flags);
1181         if (pp->cmd.status == 1) {
1182                 if (file->f_flags & O_NONBLOCK)
1183                         return -EAGAIN;
1184                 add_wait_queue(&pp->wait, &wait);
1185                 for (;;) {
1186                         set_current_state(TASK_INTERRUPTIBLE);
1187                         rc = 0;
1188                         if (pp->cmd.status != 1)
1189                                 break;
1190                         rc = -ERESTARTSYS;
1191                         if (signal_pending(current))
1192                                 break;
1193                         spin_unlock_irqrestore(&pp->lock, flags);
1194                         schedule();
1195                         spin_lock_irqsave(&pp->lock, flags);
1196                 }
1197                 set_current_state(TASK_RUNNING);
1198                 remove_wait_queue(&pp->wait, &wait);
1199         }
1200         spin_unlock_irqrestore(&pp->lock, flags);
1201         if (rc)
1202                 return rc;
1203         if (pp->cmd.status != 0)
1204                 pp->cmd.reply_len = 0;
1205         size = sizeof(hdr) + pp->cmd.reply_len;
1206         if (count < size)
1207                 size = count;
1208         rc = size;
1209         hdr.status = pp->cmd.status;
1210         hdr.reply_len = pp->cmd.reply_len;
1211         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1212                 return -EFAULT;
1213         size -= sizeof(hdr);
1214         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1215                 return -EFAULT;
1216         pp->busy = 0;
1217
1218         return rc;
1219 }
1220
1221
1222 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1223                                char __user *buf, size_t count)
1224 {
1225         /* Not implemented */
1226         msleep_interruptible(1000);
1227         return 0;
1228 }
1229
1230
1231 static ssize_t smu_read(struct file *file, char __user *buf,
1232                         size_t count, loff_t *ppos)
1233 {
1234         struct smu_private *pp = file->private_data;
1235
1236         if (pp->mode == smu_file_commands)
1237                 return smu_read_command(file, pp, buf, count);
1238         if (pp->mode == smu_file_events)
1239                 return smu_read_events(file, pp, buf, count);
1240
1241         return -EBADFD;
1242 }
1243
1244 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1245 {
1246         struct smu_private *pp = file->private_data;
1247         unsigned int mask = 0;
1248         unsigned long flags;
1249
1250         if (pp == 0)
1251                 return 0;
1252
1253         if (pp->mode == smu_file_commands) {
1254                 poll_wait(file, &pp->wait, wait);
1255
1256                 spin_lock_irqsave(&pp->lock, flags);
1257                 if (pp->busy && pp->cmd.status != 1)
1258                         mask |= POLLIN;
1259                 spin_unlock_irqrestore(&pp->lock, flags);
1260         } if (pp->mode == smu_file_events) {
1261                 /* Not yet implemented */
1262         }
1263         return mask;
1264 }
1265
1266 static int smu_release(struct inode *inode, struct file *file)
1267 {
1268         struct smu_private *pp = file->private_data;
1269         unsigned long flags;
1270         unsigned int busy;
1271
1272         if (pp == 0)
1273                 return 0;
1274
1275         file->private_data = NULL;
1276
1277         /* Mark file as closing to avoid races with new request */
1278         spin_lock_irqsave(&pp->lock, flags);
1279         pp->mode = smu_file_closing;
1280         busy = pp->busy;
1281
1282         /* Wait for any pending request to complete */
1283         if (busy && pp->cmd.status == 1) {
1284                 DECLARE_WAITQUEUE(wait, current);
1285
1286                 add_wait_queue(&pp->wait, &wait);
1287                 for (;;) {
1288                         set_current_state(TASK_UNINTERRUPTIBLE);
1289                         if (pp->cmd.status != 1)
1290                                 break;
1291                         spin_unlock_irqrestore(&pp->lock, flags);
1292                         schedule();
1293                         spin_lock_irqsave(&pp->lock, flags);
1294                 }
1295                 set_current_state(TASK_RUNNING);
1296                 remove_wait_queue(&pp->wait, &wait);
1297         }
1298         spin_unlock_irqrestore(&pp->lock, flags);
1299
1300         spin_lock_irqsave(&smu_clist_lock, flags);
1301         list_del(&pp->list);
1302         spin_unlock_irqrestore(&smu_clist_lock, flags);
1303         kfree(pp);
1304
1305         return 0;
1306 }
1307
1308
1309 static const struct file_operations smu_device_fops = {
1310         .llseek         = no_llseek,
1311         .read           = smu_read,
1312         .write          = smu_write,
1313         .poll           = smu_fpoll,
1314         .open           = smu_open,
1315         .release        = smu_release,
1316 };
1317
1318 static struct miscdevice pmu_device = {
1319         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1320 };
1321
1322 static int smu_device_init(void)
1323 {
1324         if (!smu)
1325                 return -ENODEV;
1326         if (misc_register(&pmu_device) < 0)
1327                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1328         return 0;
1329 }
1330 device_initcall(smu_device_init);