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(struct timer_list *t);
 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         timer_setup(&smu->i2c_timer, smu_i2c_retry, 0);
 586
 587         if (smu->db_node) {
 588                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 589                 if (!smu->db_irq)
 590                         printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 591                                smu->db_node);
 592         }
 593         if (smu->msg_node) {
 594                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 595                 if (!smu->msg_irq)
 596                         printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 597                                smu->msg_node);
 598         }
 599
 600         /*
 601          * Try to request the interrupts
 602          */
 603
 604         if (smu->db_irq) {
 605                 if (request_irq(smu->db_irq, smu_db_intr,
 606                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 607                         printk(KERN_WARNING "SMU: can't "
 608                                "request interrupt %d\n",
 609                                smu->db_irq);
 610                         smu->db_irq = 0;
 611                 }
 612         }
 613
 614         if (smu->msg_irq) {
 615                 if (request_irq(smu->msg_irq, smu_msg_intr,
 616                                 IRQF_SHARED, "SMU message", smu) < 0) {
 617                         printk(KERN_WARNING "SMU: can't "
 618                                "request interrupt %d\n",
 619                                smu->msg_irq);
 620                         smu->msg_irq = 0;
 621                 }
 622         }
 623
 624         smu_irq_inited = 1;
 625         return 0;
 626 }
 627 /* This has to be before arch_initcall as the low i2c stuff relies on the
 628  * above having been done before we reach arch_initcalls
 629  */
 630 core_initcall(smu_late_init);
 631
 632 /*
 633  * sysfs visibility
 634  */
 635
 636 static void smu_expose_childs(struct work_struct *unused)
 637 {
 638         struct device_node *np;
 639
 640         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 641                 if (of_device_is_compatible(np, "smu-sensors"))
 642                         of_platform_device_create(np, "smu-sensors",
 643                                                   &smu->of_dev->dev);
 644 }
 645
 646 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 647
 648 static int smu_platform_probe(struct platform_device* dev)
 649 {
 650         if (!smu)
 651                 return -ENODEV;
 652         smu->of_dev = dev;
 653
 654         /*
 655          * Ok, we are matched, now expose all i2c busses. We have to defer
 656          * that unfortunately or it would deadlock inside the device model
 657          */
 658         schedule_work(&smu_expose_childs_work);
 659
 660         return 0;
 661 }
 662
 663 static const struct of_device_id smu_platform_match[] =
 664 {
 665         {
 666                 .type           = "smu",
 667         },
 668         {},
 669 };
 670
 671 static struct platform_driver smu_of_platform_driver =
 672 {
 673         .driver = {
 674                 .name = "smu",
 675                 .of_match_table = smu_platform_match,
 676         },
 677         .probe          = smu_platform_probe,
 678 };
 679
 680 static int __init smu_init_sysfs(void)
 681 {
 682         /*
 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         platform_driver_register(&smu_of_platform_driver);
 688         return 0;
 689 }
 690
 691 device_initcall(smu_init_sysfs);
 692
 693 struct platform_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(struct timer_list *unused)
 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(NULL);
 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 (of_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         mutex_lock(&smu_mutex);
1094         spin_lock_irqsave(&smu_clist_lock, flags);
1095         list_add(&pp->list, &smu_clist);
1096         spin_unlock_irqrestore(&smu_clist_lock, flags);
1097         file->private_data = pp;
1098         mutex_unlock(&smu_mutex);
1099
1100         return 0;
1101 }
1102
1103
1104 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1105 {
1106         struct smu_private *pp = misc;
1107
1108         wake_up_all(&pp->wait);
1109 }
1110
1111
1112 static ssize_t smu_write(struct file *file, const char __user *buf,
1113                          size_t count, loff_t *ppos)
1114 {
1115         struct smu_private *pp = file->private_data;
1116         unsigned long flags;
1117         struct smu_user_cmd_hdr hdr;
1118         int rc = 0;
1119
1120         if (pp->busy)
1121                 return -EBUSY;
1122         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1123                 return -EFAULT;
1124         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1125                 pp->mode = smu_file_events;
1126                 return 0;
1127         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1128                 const struct smu_sdbp_header *part;
1129                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1130                 if (part == NULL)
1131                         return -EINVAL;
1132                 else if (IS_ERR(part))
1133                         return PTR_ERR(part);
1134                 return 0;
1135         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1136                 return -EINVAL;
1137         else if (pp->mode != smu_file_commands)
1138                 return -EBADFD;
1139         else if (hdr.data_len > SMU_MAX_DATA)
1140                 return -EINVAL;
1141
1142         spin_lock_irqsave(&pp->lock, flags);
1143         if (pp->busy) {
1144                 spin_unlock_irqrestore(&pp->lock, flags);
1145                 return -EBUSY;
1146         }
1147         pp->busy = 1;
1148         pp->cmd.status = 1;
1149         spin_unlock_irqrestore(&pp->lock, flags);
1150
1151         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1152                 pp->busy = 0;
1153                 return -EFAULT;
1154         }
1155
1156         pp->cmd.cmd = hdr.cmd;
1157         pp->cmd.data_len = hdr.data_len;
1158         pp->cmd.reply_len = SMU_MAX_DATA;
1159         pp->cmd.data_buf = pp->buffer;
1160         pp->cmd.reply_buf = pp->buffer;
1161         pp->cmd.done = smu_user_cmd_done;
1162         pp->cmd.misc = pp;
1163         rc = smu_queue_cmd(&pp->cmd);
1164         if (rc < 0)
1165                 return rc;
1166         return count;
1167 }
1168
1169
1170 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1171                                 char __user *buf, size_t count)
1172 {
1173         DECLARE_WAITQUEUE(wait, current);
1174         struct smu_user_reply_hdr hdr;
1175         unsigned long flags;
1176         int size, rc = 0;
1177
1178         if (!pp->busy)
1179                 return 0;
1180         if (count < sizeof(struct smu_user_reply_hdr))
1181                 return -EOVERFLOW;
1182         spin_lock_irqsave(&pp->lock, flags);
1183         if (pp->cmd.status == 1) {
1184                 if (file->f_flags & O_NONBLOCK) {
1185                         spin_unlock_irqrestore(&pp->lock, flags);
1186                         return -EAGAIN;
1187                 }
1188                 add_wait_queue(&pp->wait, &wait);
1189                 for (;;) {
1190                         set_current_state(TASK_INTERRUPTIBLE);
1191                         rc = 0;
1192                         if (pp->cmd.status != 1)
1193                                 break;
1194                         rc = -ERESTARTSYS;
1195                         if (signal_pending(current))
1196                                 break;
1197                         spin_unlock_irqrestore(&pp->lock, flags);
1198                         schedule();
1199                         spin_lock_irqsave(&pp->lock, flags);
1200                 }
1201                 set_current_state(TASK_RUNNING);
1202                 remove_wait_queue(&pp->wait, &wait);
1203         }
1204         spin_unlock_irqrestore(&pp->lock, flags);
1205         if (rc)
1206                 return rc;
1207         if (pp->cmd.status != 0)
1208                 pp->cmd.reply_len = 0;
1209         size = sizeof(hdr) + pp->cmd.reply_len;
1210         if (count < size)
1211                 size = count;
1212         rc = size;
1213         hdr.status = pp->cmd.status;
1214         hdr.reply_len = pp->cmd.reply_len;
1215         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1216                 return -EFAULT;
1217         size -= sizeof(hdr);
1218         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1219                 return -EFAULT;
1220         pp->busy = 0;
1221
1222         return rc;
1223 }
1224
1225
1226 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1227                                char __user *buf, size_t count)
1228 {
1229         /* Not implemented */
1230         msleep_interruptible(1000);
1231         return 0;
1232 }
1233
1234
1235 static ssize_t smu_read(struct file *file, char __user *buf,
1236                         size_t count, loff_t *ppos)
1237 {
1238         struct smu_private *pp = file->private_data;
1239
1240         if (pp->mode == smu_file_commands)
1241                 return smu_read_command(file, pp, buf, count);
1242         if (pp->mode == smu_file_events)
1243                 return smu_read_events(file, pp, buf, count);
1244
1245         return -EBADFD;
1246 }
1247
1248 static __poll_t smu_fpoll(struct file *file, poll_table *wait)
1249 {
1250         struct smu_private *pp = file->private_data;
1251         __poll_t mask = 0;
1252         unsigned long flags;
1253
1254         if (pp == 0)
1255                 return 0;
1256
1257         if (pp->mode == smu_file_commands) {
1258                 poll_wait(file, &pp->wait, wait);
1259
1260                 spin_lock_irqsave(&pp->lock, flags);
1261                 if (pp->busy && pp->cmd.status != 1)
1262                         mask |= EPOLLIN;
1263                 spin_unlock_irqrestore(&pp->lock, flags);
1264         }
1265         if (pp->mode == smu_file_events) {
1266                 /* Not yet implemented */
1267         }
1268         return mask;
1269 }
1270
1271 static int smu_release(struct inode *inode, struct file *file)
1272 {
1273         struct smu_private *pp = file->private_data;
1274         unsigned long flags;
1275         unsigned int busy;
1276
1277         if (pp == 0)
1278                 return 0;
1279
1280         file->private_data = NULL;
1281
1282         /* Mark file as closing to avoid races with new request */
1283         spin_lock_irqsave(&pp->lock, flags);
1284         pp->mode = smu_file_closing;
1285         busy = pp->busy;
1286
1287         /* Wait for any pending request to complete */
1288         if (busy && pp->cmd.status == 1) {
1289                 DECLARE_WAITQUEUE(wait, current);
1290
1291                 add_wait_queue(&pp->wait, &wait);
1292                 for (;;) {
1293                         set_current_state(TASK_UNINTERRUPTIBLE);
1294                         if (pp->cmd.status != 1)
1295                                 break;
1296                         spin_unlock_irqrestore(&pp->lock, flags);
1297                         schedule();
1298                         spin_lock_irqsave(&pp->lock, flags);
1299                 }
1300                 set_current_state(TASK_RUNNING);
1301                 remove_wait_queue(&pp->wait, &wait);
1302         }
1303         spin_unlock_irqrestore(&pp->lock, flags);
1304
1305         spin_lock_irqsave(&smu_clist_lock, flags);
1306         list_del(&pp->list);
1307         spin_unlock_irqrestore(&smu_clist_lock, flags);
1308         kfree(pp);
1309
1310         return 0;
1311 }
1312
1313
1314 static const struct file_operations smu_device_fops = {
1315         .llseek         = no_llseek,
1316         .read           = smu_read,
1317         .write          = smu_write,
1318         .poll           = smu_fpoll,
1319         .open           = smu_open,
1320         .release        = smu_release,
1321 };
1322
1323 static struct miscdevice pmu_device = {
1324         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1325 };
1326
1327 static int smu_device_init(void)
1328 {
1329         if (!smu)
1330                 return -ENODEV;
1331         if (misc_register(&pmu_device) < 0)
1332                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1333         return 0;
1334 }
1335 device_initcall(smu_device_init);