drivers/macintosh/smu.c

   1 /*
   2  * PowerMac G5 SMU driver
   3  *
   4  * Copyright 2004 J. Mayer <[email protected]>
   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_platform.h>
  39 #include <linux/slab.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/uaccess.h>
  49
  50 #define VERSION "0.7"
  51 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  52
  53 #undef DEBUG_SMU
  54
  55 #ifdef DEBUG_SMU
  56 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  57 #else
  58 #define DPRINTK(fmt, args...) do { } while (0)
  59 #endif
  60
  61 /*
  62  * This is the command buffer passed to the SMU hardware
  63  */
  64 #define SMU_MAX_DATA    254
  65
  66 struct smu_cmd_buf {
  67         u8 cmd;
  68         u8 length;
  69         u8 data[SMU_MAX_DATA];
  70 };
  71
  72 struct smu_device {
  73         spinlock_t              lock;
  74         struct device_node      *of_node;
  75         struct platform_device  *of_dev;
  76         int                     doorbell;       /* doorbell gpio */
  77         u32 __iomem             *db_buf;        /* doorbell buffer */
  78         struct device_node      *db_node;
  79         unsigned int            db_irq;
  80         int                     msg;
  81         struct device_node      *msg_node;
  82         unsigned int            msg_irq;
  83         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  84         u32                     cmd_buf_abs;    /* command buffer absolute */
  85         struct list_head        cmd_list;
  86         struct smu_cmd          *cmd_cur;       /* pending command */
  87         int                     broken_nap;
  88         struct list_head        cmd_i2c_list;
  89         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  90         struct timer_list       i2c_timer;
  91 };
  92
  93 /*
  94  * I don't think there will ever be more than one SMU, so
  95  * for now, just hard code that
  96  */
  97 static DEFINE_MUTEX(smu_mutex);
  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: %8ph\n", cmd->data_buf);
 124
 125         /* Fill the SMU command buffer */
 126         smu->cmd_buf->cmd = cmd->cmd;
 127         smu->cmd_buf->length = cmd->data_len;
 128         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 129
 130         /* Flush command and data to RAM */
 131         faddr = (unsigned long)smu->cmd_buf;
 132         fend = faddr + smu->cmd_buf->length + 2;
 133         flush_inval_dcache_range(faddr, fend);
 134
 135
 136         /* We also disable NAP mode for the duration of the command
 137          * on U3 based machines.
 138          * This is slightly racy as it can be written back to 1 by a sysctl
 139          * but that never happens in practice. There seem to be an issue with
 140          * U3 based machines such as the iMac G5 where napping for the
 141          * whole duration of the command prevents the SMU from fetching it
 142          * from memory. This might be related to the strange i2c based
 143          * mechanism the SMU uses to access memory.
 144          */
 145         if (smu->broken_nap)
 146                 powersave_nap = 0;
 147
 148         /* This isn't exactly a DMA mapping here, I suspect
 149          * the SMU is actually communicating with us via i2c to the
 150          * northbridge or the CPU to access RAM.
 151          */
 152         writel(smu->cmd_buf_abs, smu->db_buf);
 153
 154         /* Ring the SMU doorbell */
 155         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 156 }
 157
 158
 159 static irqreturn_t smu_db_intr(int irq, void *arg)
 160 {
 161         unsigned long flags;
 162         struct smu_cmd *cmd;
 163         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 164         void *misc = NULL;
 165         u8 gpio;
 166         int rc = 0;
 167
 168         /* SMU completed the command, well, we hope, let's make sure
 169          * of it
 170          */
 171         spin_lock_irqsave(&smu->lock, flags);
 172
 173         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 174         if ((gpio & 7) != 7) {
 175                 spin_unlock_irqrestore(&smu->lock, flags);
 176                 return IRQ_HANDLED;
 177         }
 178
 179         cmd = smu->cmd_cur;
 180         smu->cmd_cur = NULL;
 181         if (cmd == NULL)
 182                 goto bail;
 183
 184         if (rc == 0) {
 185                 unsigned long faddr;
 186                 int reply_len;
 187                 u8 ack;
 188
 189                 /* CPU might have brought back the cache line, so we need
 190                  * to flush again before peeking at the SMU response. We
 191                  * flush the entire buffer for now as we haven't read the
 192                  * reply length (it's only 2 cache lines anyway)
 193                  */
 194                 faddr = (unsigned long)smu->cmd_buf;
 195                 flush_inval_dcache_range(faddr, faddr + 256);
 196
 197                 /* Now check ack */
 198                 ack = (~cmd->cmd) & 0xff;
 199                 if (ack != smu->cmd_buf->cmd) {
 200                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 201                                 ack, smu->cmd_buf->cmd);
 202                         rc = -EIO;
 203                 }
 204                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 205                 DPRINTK("SMU: reply len: %d\n", reply_len);
 206                 if (reply_len > cmd->reply_len) {
 207                         printk(KERN_WARNING "SMU: reply buffer too small,"
 208                                "got %d bytes for a %d bytes buffer\n",
 209                                reply_len, cmd->reply_len);
 210                         reply_len = cmd->reply_len;
 211                 }
 212                 cmd->reply_len = reply_len;
 213                 if (cmd->reply_buf && reply_len)
 214                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 215         }
 216
 217         /* Now complete the command. Write status last in order as we lost
 218          * ownership of the command structure as soon as it's no longer -1
 219          */
 220         done = cmd->done;
 221         misc = cmd->misc;
 222         mb();
 223         cmd->status = rc;
 224
 225         /* Re-enable NAP mode */
 226         if (smu->broken_nap)
 227                 powersave_nap = 1;
 228  bail:
 229         /* Start next command if any */
 230         smu_start_cmd();
 231         spin_unlock_irqrestore(&smu->lock, flags);
 232
 233         /* Call command completion handler if any */
 234         if (done)
 235                 done(cmd, misc);
 236
 237         /* It's an edge interrupt, nothing to do */
 238         return IRQ_HANDLED;
 239 }
 240
 241
 242 static irqreturn_t smu_msg_intr(int irq, void *arg)
 243 {
 244         /* I don't quite know what to do with this one, we seem to never
 245          * receive it, so I suspect we have to arm it someway in the SMU
 246          * to start getting events that way.
 247          */
 248
 249         printk(KERN_INFO "SMU: message interrupt !\n");
 250
 251         /* It's an edge interrupt, nothing to do */
 252         return IRQ_HANDLED;
 253 }
 254
 255
 256 /*
 257  * Queued command management.
 258  *
 259  */
 260
 261 int smu_queue_cmd(struct smu_cmd *cmd)
 262 {
 263         unsigned long flags;
 264
 265         if (smu == NULL)
 266                 return -ENODEV;
 267         if (cmd->data_len > SMU_MAX_DATA ||
 268             cmd->reply_len > SMU_MAX_DATA)
 269                 return -EINVAL;
 270
 271         cmd->status = 1;
 272         spin_lock_irqsave(&smu->lock, flags);
 273         list_add_tail(&cmd->link, &smu->cmd_list);
 274         if (smu->cmd_cur == NULL)
 275                 smu_start_cmd();
 276         spin_unlock_irqrestore(&smu->lock, flags);
 277
 278         /* Workaround for early calls when irq isn't available */
 279         if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 280                 smu_spinwait_cmd(cmd);
 281
 282         return 0;
 283 }
 284 EXPORT_SYMBOL(smu_queue_cmd);
 285
 286
 287 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 288                      unsigned int data_len,
 289                      void (*done)(struct smu_cmd *cmd, void *misc),
 290                      void *misc, ...)
 291 {
 292         struct smu_cmd *cmd = &scmd->cmd;
 293         va_list list;
 294         int i;
 295
 296         if (data_len > sizeof(scmd->buffer))
 297                 return -EINVAL;
 298
 299         memset(scmd, 0, sizeof(*scmd));
 300         cmd->cmd = command;
 301         cmd->data_len = data_len;
 302         cmd->data_buf = scmd->buffer;
 303         cmd->reply_len = sizeof(scmd->buffer);
 304         cmd->reply_buf = scmd->buffer;
 305         cmd->done = done;
 306         cmd->misc = misc;
 307
 308         va_start(list, misc);
 309         for (i = 0; i < data_len; ++i)
 310                 scmd->buffer[i] = (u8)va_arg(list, int);
 311         va_end(list);
 312
 313         return smu_queue_cmd(cmd);
 314 }
 315 EXPORT_SYMBOL(smu_queue_simple);
 316
 317
 318 void smu_poll(void)
 319 {
 320         u8 gpio;
 321
 322         if (smu == NULL)
 323                 return;
 324
 325         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 326         if ((gpio & 7) == 7)
 327                 smu_db_intr(smu->db_irq, smu);
 328 }
 329 EXPORT_SYMBOL(smu_poll);
 330
 331
 332 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 333 {
 334         struct completion *comp = misc;
 335
 336         complete(comp);
 337 }
 338 EXPORT_SYMBOL(smu_done_complete);
 339
 340
 341 void smu_spinwait_cmd(struct smu_cmd *cmd)
 342 {
 343         while(cmd->status == 1)
 344                 smu_poll();
 345 }
 346 EXPORT_SYMBOL(smu_spinwait_cmd);
 347
 348
 349 /* RTC low level commands */
 350 static inline int bcd2hex (int n)
 351 {
 352         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 353 }
 354
 355
 356 static inline int hex2bcd (int n)
 357 {
 358         return ((n / 10) << 4) + (n % 10);
 359 }
 360
 361
 362 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 363                                         struct rtc_time *time)
 364 {
 365         cmd_buf->cmd = 0x8e;
 366         cmd_buf->length = 8;
 367         cmd_buf->data[0] = 0x80;
 368         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 369         cmd_buf->data[2] = hex2bcd(time->tm_min);
 370         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 371         cmd_buf->data[4] = time->tm_wday;
 372         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 373         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 374         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 375 }
 376
 377
 378 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 379 {
 380         struct smu_simple_cmd cmd;
 381         int rc;
 382
 383         if (smu == NULL)
 384                 return -ENODEV;
 385
 386         memset(time, 0, sizeof(struct rtc_time));
 387         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 388                               SMU_CMD_RTC_GET_DATETIME);
 389         if (rc)
 390                 return rc;
 391         smu_spinwait_simple(&cmd);
 392
 393         time->tm_sec = bcd2hex(cmd.buffer[0]);
 394         time->tm_min = bcd2hex(cmd.buffer[1]);
 395         time->tm_hour = bcd2hex(cmd.buffer[2]);
 396         time->tm_wday = bcd2hex(cmd.buffer[3]);
 397         time->tm_mday = bcd2hex(cmd.buffer[4]);
 398         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 399         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 400
 401         return 0;
 402 }
 403
 404
 405 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 406 {
 407         struct smu_simple_cmd cmd;
 408         int rc;
 409
 410         if (smu == NULL)
 411                 return -ENODEV;
 412
 413         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 414                               SMU_CMD_RTC_SET_DATETIME,
 415                               hex2bcd(time->tm_sec),
 416                               hex2bcd(time->tm_min),
 417                               hex2bcd(time->tm_hour),
 418                               time->tm_wday,
 419                               hex2bcd(time->tm_mday),
 420                               hex2bcd(time->tm_mon) + 1,
 421                               hex2bcd(time->tm_year - 100));
 422         if (rc)
 423                 return rc;
 424         smu_spinwait_simple(&cmd);
 425
 426         return 0;
 427 }
 428
 429
 430 void smu_shutdown(void)
 431 {
 432         struct smu_simple_cmd cmd;
 433
 434         if (smu == NULL)
 435                 return;
 436
 437         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 438                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 439                 return;
 440         smu_spinwait_simple(&cmd);
 441         for (;;)
 442                 ;
 443 }
 444
 445
 446 void smu_restart(void)
 447 {
 448         struct smu_simple_cmd cmd;
 449
 450         if (smu == NULL)
 451                 return;
 452
 453         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 454                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 455                 return;
 456         smu_spinwait_simple(&cmd);
 457         for (;;)
 458                 ;
 459 }
 460
 461
 462 int smu_present(void)
 463 {
 464         return smu != NULL;
 465 }
 466 EXPORT_SYMBOL(smu_present);
 467
 468
 469 int __init smu_init (void)
 470 {
 471         struct device_node *np;
 472         const u32 *data;
 473         int ret = 0;
 474
 475         np = of_find_node_by_type(NULL, "smu");
 476         if (np == NULL)
 477                 return -ENODEV;
 478
 479         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 480
 481         if (smu_cmdbuf_abs == 0) {
 482                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 483                 ret = -EINVAL;
 484                 goto fail_np;
 485         }
 486
 487         smu = alloc_bootmem(sizeof(struct smu_device));
 488
 489         spin_lock_init(&smu->lock);
 490         INIT_LIST_HEAD(&smu->cmd_list);
 491         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 492         smu->of_node = np;
 493         smu->db_irq = NO_IRQ;
 494         smu->msg_irq = NO_IRQ;
 495
 496         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 497          * 32 bits value safely
 498          */
 499         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 500         smu->cmd_buf = __va(smu_cmdbuf_abs);
 501
 502         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 503         if (smu->db_node == NULL) {
 504                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 505                 ret = -ENXIO;
 506                 goto fail_bootmem;
 507         }
 508         data = of_get_property(smu->db_node, "reg", NULL);
 509         if (data == NULL) {
 510                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 511                 ret = -ENXIO;
 512                 goto fail_db_node;
 513         }
 514
 515         /* Current setup has one doorbell GPIO that does both doorbell
 516          * and ack. GPIOs are at 0x50, best would be to find that out
 517          * in the device-tree though.
 518          */
 519         smu->doorbell = *data;
 520         if (smu->doorbell < 0x50)
 521                 smu->doorbell += 0x50;
 522
 523         /* Now look for the smu-interrupt GPIO */
 524         do {
 525                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 526                 if (smu->msg_node == NULL)
 527                         break;
 528                 data = of_get_property(smu->msg_node, "reg", NULL);
 529                 if (data == NULL) {
 530                         of_node_put(smu->msg_node);
 531                         smu->msg_node = NULL;
 532                         break;
 533                 }
 534                 smu->msg = *data;
 535                 if (smu->msg < 0x50)
 536                         smu->msg += 0x50;
 537         } while(0);
 538
 539         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 540          * device-tree entry giving the address. Best would probably to use
 541          * an offset for K2 base though, but let's do it that way for now.
 542          */
 543         smu->db_buf = ioremap(0x8000860c, 0x1000);
 544         if (smu->db_buf == NULL) {
 545                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 546                 ret = -ENXIO;
 547                 goto fail_msg_node;
 548         }
 549
 550         /* U3 has an issue with NAP mode when issuing SMU commands */
 551         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 552         if (smu->broken_nap)
 553                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 554
 555         sys_ctrler = SYS_CTRLER_SMU;
 556         return 0;
 557
 558 fail_msg_node:
 559         if (smu->msg_node)
 560                 of_node_put(smu->msg_node);
 561 fail_db_node:
 562         of_node_put(smu->db_node);
 563 fail_bootmem:
 564         free_bootmem(__pa(smu), sizeof(struct smu_device));
 565         smu = NULL;
 566 fail_np:
 567         of_node_put(np);
 568         return ret;
 569 }
 570
 571
 572 static int smu_late_init(void)
 573 {
 574         if (!smu)
 575                 return 0;
 576
 577         init_timer(&smu->i2c_timer);
 578         smu->i2c_timer.function = smu_i2c_retry;
 579         smu->i2c_timer.data = (unsigned long)smu;
 580
 581         if (smu->db_node) {
 582                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 583                 if (smu->db_irq == NO_IRQ)
 584                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 585                                smu->db_node->full_name);
 586         }
 587         if (smu->msg_node) {
 588                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 589                 if (smu->msg_irq == NO_IRQ)
 590                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 591                                smu->msg_node->full_name);
 592         }
 593
 594         /*
 595          * Try to request the interrupts
 596          */
 597
 598         if (smu->db_irq != NO_IRQ) {
 599                 if (request_irq(smu->db_irq, smu_db_intr,
 600                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 601                         printk(KERN_WARNING "SMU: can't "
 602                                "request interrupt %d\n",
 603                                smu->db_irq);
 604                         smu->db_irq = NO_IRQ;
 605                 }
 606         }
 607
 608         if (smu->msg_irq != NO_IRQ) {
 609                 if (request_irq(smu->msg_irq, smu_msg_intr,
 610                                 IRQF_SHARED, "SMU message", smu) < 0) {
 611                         printk(KERN_WARNING "SMU: can't "
 612                                "request interrupt %d\n",
 613                                smu->msg_irq);
 614                         smu->msg_irq = NO_IRQ;
 615                 }
 616         }
 617
 618         smu_irq_inited = 1;
 619         return 0;
 620 }
 621 /* This has to be before arch_initcall as the low i2c stuff relies on the
 622  * above having been done before we reach arch_initcalls
 623  */
 624 core_initcall(smu_late_init);
 625
 626 /*
 627  * sysfs visibility
 628  */
 629
 630 static void smu_expose_childs(struct work_struct *unused)
 631 {
 632         struct device_node *np;
 633
 634         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 635                 if (of_device_is_compatible(np, "smu-sensors"))
 636                         of_platform_device_create(np, "smu-sensors",
 637                                                   &smu->of_dev->dev);
 638 }
 639
 640 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 641
 642 static int smu_platform_probe(struct platform_device* dev)
 643 {
 644         if (!smu)
 645                 return -ENODEV;
 646         smu->of_dev = dev;
 647
 648         /*
 649          * Ok, we are matched, now expose all i2c busses. We have to defer
 650          * that unfortunately or it would deadlock inside the device model
 651          */
 652         schedule_work(&smu_expose_childs_work);
 653
 654         return 0;
 655 }
 656
 657 static const struct of_device_id smu_platform_match[] =
 658 {
 659         {
 660                 .type           = "smu",
 661         },
 662         {},
 663 };
 664
 665 static struct platform_driver smu_of_platform_driver =
 666 {
 667         .driver = {
 668                 .name = "smu",
 669                 .owner = THIS_MODULE,
 670                 .of_match_table = smu_platform_match,
 671         },
 672         .probe          = smu_platform_probe,
 673 };
 674
 675 static int __init smu_init_sysfs(void)
 676 {
 677         /*
 678          * For now, we don't power manage machines with an SMU chip,
 679          * I'm a bit too far from figuring out how that works with those
 680          * new chipsets, but that will come back and bite us
 681          */
 682         platform_driver_register(&smu_of_platform_driver);
 683         return 0;
 684 }
 685
 686 device_initcall(smu_init_sysfs);
 687
 688 struct platform_device *smu_get_ofdev(void)
 689 {
 690         if (!smu)
 691                 return NULL;
 692         return smu->of_dev;
 693 }
 694
 695 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 696
 697 /*
 698  * i2c interface
 699  */
 700
 701 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 702 {
 703         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 704         void *misc = cmd->misc;
 705         unsigned long flags;
 706
 707         /* Check for read case */
 708         if (!fail && cmd->read) {
 709                 if (cmd->pdata[0] < 1)
 710                         fail = 1;
 711                 else
 712                         memcpy(cmd->info.data, &cmd->pdata[1],
 713                                cmd->info.datalen);
 714         }
 715
 716         DPRINTK("SMU: completing, success: %d\n", !fail);
 717
 718         /* Update status and mark no pending i2c command with lock
 719          * held so nobody comes in while we dequeue an eventual
 720          * pending next i2c command
 721          */
 722         spin_lock_irqsave(&smu->lock, flags);
 723         smu->cmd_i2c_cur = NULL;
 724         wmb();
 725         cmd->status = fail ? -EIO : 0;
 726
 727         /* Is there another i2c command waiting ? */
 728         if (!list_empty(&smu->cmd_i2c_list)) {
 729                 struct smu_i2c_cmd *newcmd;
 730
 731                 /* Fetch it, new current, remove from list */
 732                 newcmd = list_entry(smu->cmd_i2c_list.next,
 733                                     struct smu_i2c_cmd, link);
 734                 smu->cmd_i2c_cur = newcmd;
 735                 list_del(&cmd->link);
 736
 737                 /* Queue with low level smu */
 738                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 739                 if (smu->cmd_cur == NULL)
 740                         smu_start_cmd();
 741         }
 742         spin_unlock_irqrestore(&smu->lock, flags);
 743
 744         /* Call command completion handler if any */
 745         if (done)
 746                 done(cmd, misc);
 747
 748 }
 749
 750
 751 static void smu_i2c_retry(unsigned long data)
 752 {
 753         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 754
 755         DPRINTK("SMU: i2c failure, requeuing...\n");
 756
 757         /* requeue command simply by resetting reply_len */
 758         cmd->pdata[0] = 0xff;
 759         cmd->scmd.reply_len = sizeof(cmd->pdata);
 760         smu_queue_cmd(&cmd->scmd);
 761 }
 762
 763
 764 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 765 {
 766         struct smu_i2c_cmd      *cmd = misc;
 767         int                     fail = 0;
 768
 769         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 770                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 771
 772         /* Check for possible status */
 773         if (scmd->status < 0)
 774                 fail = 1;
 775         else if (cmd->read) {
 776                 if (cmd->stage == 0)
 777                         fail = cmd->pdata[0] != 0;
 778                 else
 779                         fail = cmd->pdata[0] >= 0x80;
 780         } else {
 781                 fail = cmd->pdata[0] != 0;
 782         }
 783
 784         /* Handle failures by requeuing command, after 5ms interval
 785          */
 786         if (fail && --cmd->retries > 0) {
 787                 DPRINTK("SMU: i2c failure, starting timer...\n");
 788                 BUG_ON(cmd != smu->cmd_i2c_cur);
 789                 if (!smu_irq_inited) {
 790                         mdelay(5);
 791                         smu_i2c_retry(0);
 792                         return;
 793                 }
 794                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 795                 return;
 796         }
 797
 798         /* If failure or stage 1, command is complete */
 799         if (fail || cmd->stage != 0) {
 800                 smu_i2c_complete_command(cmd, fail);
 801                 return;
 802         }
 803
 804         DPRINTK("SMU: going to stage 1\n");
 805
 806         /* Ok, initial command complete, now poll status */
 807         scmd->reply_buf = cmd->pdata;
 808         scmd->reply_len = sizeof(cmd->pdata);
 809         scmd->data_buf = cmd->pdata;
 810         scmd->data_len = 1;
 811         cmd->pdata[0] = 0;
 812         cmd->stage = 1;
 813         cmd->retries = 20;
 814         smu_queue_cmd(scmd);
 815 }
 816
 817
 818 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 819 {
 820         unsigned long flags;
 821
 822         if (smu == NULL)
 823                 return -ENODEV;
 824
 825         /* Fill most fields of scmd */
 826         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 827         cmd->scmd.done = smu_i2c_low_completion;
 828         cmd->scmd.misc = cmd;
 829         cmd->scmd.reply_buf = cmd->pdata;
 830         cmd->scmd.reply_len = sizeof(cmd->pdata);
 831         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 832         cmd->scmd.status = 1;
 833         cmd->stage = 0;
 834         cmd->pdata[0] = 0xff;
 835         cmd->retries = 20;
 836         cmd->status = 1;
 837
 838         /* Check transfer type, sanitize some "info" fields
 839          * based on transfer type and do more checking
 840          */
 841         cmd->info.caddr = cmd->info.devaddr;
 842         cmd->read = cmd->info.devaddr & 0x01;
 843         switch(cmd->info.type) {
 844         case SMU_I2C_TRANSFER_SIMPLE:
 845                 memset(&cmd->info.sublen, 0, 4);
 846                 break;
 847         case SMU_I2C_TRANSFER_COMBINED:
 848                 cmd->info.devaddr &= 0xfe;
 849         case SMU_I2C_TRANSFER_STDSUB:
 850                 if (cmd->info.sublen > 3)
 851                         return -EINVAL;
 852                 break;
 853         default:
 854                 return -EINVAL;
 855         }
 856
 857         /* Finish setting up command based on transfer direction
 858          */
 859         if (cmd->read) {
 860                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 861                         return -EINVAL;
 862                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 863                 cmd->scmd.data_len = 9;
 864         } else {
 865                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 866                         return -EINVAL;
 867                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 868         }
 869
 870         DPRINTK("SMU: i2c enqueuing command\n");
 871         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 872                 cmd->read ? "read" : "write", cmd->info.datalen,
 873                 cmd->info.bus, cmd->info.caddr,
 874                 cmd->info.subaddr[0], cmd->info.type);
 875
 876
 877         /* Enqueue command in i2c list, and if empty, enqueue also in
 878          * main command list
 879          */
 880         spin_lock_irqsave(&smu->lock, flags);
 881         if (smu->cmd_i2c_cur == NULL) {
 882                 smu->cmd_i2c_cur = cmd;
 883                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 884                 if (smu->cmd_cur == NULL)
 885                         smu_start_cmd();
 886         } else
 887                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 888         spin_unlock_irqrestore(&smu->lock, flags);
 889
 890         return 0;
 891 }
 892
 893 /*
 894  * Handling of "partitions"
 895  */
 896
 897 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 898 {
 899         DECLARE_COMPLETION_ONSTACK(comp);
 900         unsigned int chunk;
 901         struct smu_cmd cmd;
 902         int rc;
 903         u8 params[8];
 904
 905         /* We currently use a chunk size of 0xe. We could check the
 906          * SMU firmware version and use bigger sizes though
 907          */
 908         chunk = 0xe;
 909
 910         while (len) {
 911                 unsigned int clen = min(len, chunk);
 912
 913                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 914                 cmd.data_len = 7;
 915                 cmd.data_buf = params;
 916                 cmd.reply_len = chunk;
 917                 cmd.reply_buf = dest;
 918                 cmd.done = smu_done_complete;
 919                 cmd.misc = &comp;
 920                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 921                 params[1] = 0x4;
 922                 *((u32 *)&params[2]) = addr;
 923                 params[6] = clen;
 924
 925                 rc = smu_queue_cmd(&cmd);
 926                 if (rc)
 927                         return rc;
 928                 wait_for_completion(&comp);
 929                 if (cmd.status != 0)
 930                         return rc;
 931                 if (cmd.reply_len != clen) {
 932                         printk(KERN_DEBUG "SMU: short read in "
 933                                "smu_read_datablock, got: %d, want: %d\n",
 934                                cmd.reply_len, clen);
 935                         return -EIO;
 936                 }
 937                 len -= clen;
 938                 addr += clen;
 939                 dest += clen;
 940         }
 941         return 0;
 942 }
 943
 944 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 945 {
 946         DECLARE_COMPLETION_ONSTACK(comp);
 947         struct smu_simple_cmd cmd;
 948         unsigned int addr, len, tlen;
 949         struct smu_sdbp_header *hdr;
 950         struct property *prop;
 951
 952         /* First query the partition info */
 953         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 954         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 955                          smu_done_complete, &comp,
 956                          SMU_CMD_PARTITION_LATEST, id);
 957         wait_for_completion(&comp);
 958         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 959                 cmd.cmd.status, cmd.cmd.reply_len);
 960
 961         /* Partition doesn't exist (or other error) */
 962         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 963                 return NULL;
 964
 965         /* Fetch address and length from reply */
 966         addr = *((u16 *)cmd.buffer);
 967         len = cmd.buffer[3] << 2;
 968         /* Calucluate total length to allocate, including the 17 bytes
 969          * for "sdb-partition-XX" that we append at the end of the buffer
 970          */
 971         tlen = sizeof(struct property) + len + 18;
 972
 973         prop = kzalloc(tlen, GFP_KERNEL);
 974         if (prop == NULL)
 975                 return NULL;
 976         hdr = (struct smu_sdbp_header *)(prop + 1);
 977         prop->name = ((char *)prop) + tlen - 18;
 978         sprintf(prop->name, "sdb-partition-%02x", id);
 979         prop->length = len;
 980         prop->value = hdr;
 981         prop->next = NULL;
 982
 983         /* Read the datablock */
 984         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 985                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 986                        "partition %02x !\n", id);
 987                 goto failure;
 988         }
 989
 990         /* Got it, check a few things and create the property */
 991         if (hdr->id != id) {
 992                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 993                        "%02x !\n", id, hdr->id);
 994                 goto failure;
 995         }
 996         if (of_add_property(smu->of_node, prop)) {
 997                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 998                        "property !\n", id);
 999                 goto failure;
1000         }
1001
1002         return hdr;
1003  failure:
1004         kfree(prop);
1005         return NULL;
1006 }
1007
1008 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1009  * when interruptible is 1
1010  */
1011 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1012                 unsigned int *size, int interruptible)
1013 {
1014         char pname[32];
1015         const struct smu_sdbp_header *part;
1016
1017         if (!smu)
1018                 return NULL;
1019
1020         sprintf(pname, "sdb-partition-%02x", id);
1021
1022         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1023
1024         if (interruptible) {
1025                 int rc;
1026                 rc = mutex_lock_interruptible(&smu_part_access);
1027                 if (rc)
1028                         return ERR_PTR(rc);
1029         } else
1030                 mutex_lock(&smu_part_access);
1031
1032         part = of_get_property(smu->of_node, pname, size);
1033         if (part == NULL) {
1034                 DPRINTK("trying to extract from SMU ...\n");
1035                 part = smu_create_sdb_partition(id);
1036                 if (part != NULL && size)
1037                         *size = part->len << 2;
1038         }
1039         mutex_unlock(&smu_part_access);
1040         return part;
1041 }
1042
1043 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1044 {
1045         return __smu_get_sdb_partition(id, size, 0);
1046 }
1047 EXPORT_SYMBOL(smu_get_sdb_partition);
1048
1049
1050 /*
1051  * Userland driver interface
1052  */
1053
1054
1055 static LIST_HEAD(smu_clist);
1056 static DEFINE_SPINLOCK(smu_clist_lock);
1057
1058 enum smu_file_mode {
1059         smu_file_commands,
1060         smu_file_events,
1061         smu_file_closing
1062 };
1063
1064 struct smu_private
1065 {
1066         struct list_head        list;
1067         enum smu_file_mode      mode;
1068         int                     busy;
1069         struct smu_cmd          cmd;
1070         spinlock_t              lock;
1071         wait_queue_head_t       wait;
1072         u8                      buffer[SMU_MAX_DATA];
1073 };
1074
1075
1076 static int smu_open(struct inode *inode, struct file *file)
1077 {
1078         struct smu_private *pp;
1079         unsigned long flags;
1080
1081         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1082         if (pp == 0)
1083                 return -ENOMEM;
1084         spin_lock_init(&pp->lock);
1085         pp->mode = smu_file_commands;
1086         init_waitqueue_head(&pp->wait);
1087
1088         mutex_lock(&smu_mutex);
1089         spin_lock_irqsave(&smu_clist_lock, flags);
1090         list_add(&pp->list, &smu_clist);
1091         spin_unlock_irqrestore(&smu_clist_lock, flags);
1092         file->private_data = pp;
1093         mutex_unlock(&smu_mutex);
1094
1095         return 0;
1096 }
1097
1098
1099 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1100 {
1101         struct smu_private *pp = misc;
1102
1103         wake_up_all(&pp->wait);
1104 }
1105
1106
1107 static ssize_t smu_write(struct file *file, const char __user *buf,
1108                          size_t count, loff_t *ppos)
1109 {
1110         struct smu_private *pp = file->private_data;
1111         unsigned long flags;
1112         struct smu_user_cmd_hdr hdr;
1113         int rc = 0;
1114
1115         if (pp->busy)
1116                 return -EBUSY;
1117         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1118                 return -EFAULT;
1119         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1120                 pp->mode = smu_file_events;
1121                 return 0;
1122         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1123                 const struct smu_sdbp_header *part;
1124                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1125                 if (part == NULL)
1126                         return -EINVAL;
1127                 else if (IS_ERR(part))
1128                         return PTR_ERR(part);
1129                 return 0;
1130         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1131                 return -EINVAL;
1132         else if (pp->mode != smu_file_commands)
1133                 return -EBADFD;
1134         else if (hdr.data_len > SMU_MAX_DATA)
1135                 return -EINVAL;
1136
1137         spin_lock_irqsave(&pp->lock, flags);
1138         if (pp->busy) {
1139                 spin_unlock_irqrestore(&pp->lock, flags);
1140                 return -EBUSY;
1141         }
1142         pp->busy = 1;
1143         pp->cmd.status = 1;
1144         spin_unlock_irqrestore(&pp->lock, flags);
1145
1146         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1147                 pp->busy = 0;
1148                 return -EFAULT;
1149         }
1150
1151         pp->cmd.cmd = hdr.cmd;
1152         pp->cmd.data_len = hdr.data_len;
1153         pp->cmd.reply_len = SMU_MAX_DATA;
1154         pp->cmd.data_buf = pp->buffer;
1155         pp->cmd.reply_buf = pp->buffer;
1156         pp->cmd.done = smu_user_cmd_done;
1157         pp->cmd.misc = pp;
1158         rc = smu_queue_cmd(&pp->cmd);
1159         if (rc < 0)
1160                 return rc;
1161         return count;
1162 }
1163
1164
1165 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1166                                 char __user *buf, size_t count)
1167 {
1168         DECLARE_WAITQUEUE(wait, current);
1169         struct smu_user_reply_hdr hdr;
1170         unsigned long flags;
1171         int size, rc = 0;
1172
1173         if (!pp->busy)
1174                 return 0;
1175         if (count < sizeof(struct smu_user_reply_hdr))
1176                 return -EOVERFLOW;
1177         spin_lock_irqsave(&pp->lock, flags);
1178         if (pp->cmd.status == 1) {
1179                 if (file->f_flags & O_NONBLOCK) {
1180                         spin_unlock_irqrestore(&pp->lock, flags);
1181                         return -EAGAIN;
1182                 }
1183                 add_wait_queue(&pp->wait, &wait);
1184                 for (;;) {
1185                         set_current_state(TASK_INTERRUPTIBLE);
1186                         rc = 0;
1187                         if (pp->cmd.status != 1)
1188                                 break;
1189                         rc = -ERESTARTSYS;
1190                         if (signal_pending(current))
1191                                 break;
1192                         spin_unlock_irqrestore(&pp->lock, flags);
1193                         schedule();
1194                         spin_lock_irqsave(&pp->lock, flags);
1195                 }
1196                 set_current_state(TASK_RUNNING);
1197                 remove_wait_queue(&pp->wait, &wait);
1198         }
1199         spin_unlock_irqrestore(&pp->lock, flags);
1200         if (rc)
1201                 return rc;
1202         if (pp->cmd.status != 0)
1203                 pp->cmd.reply_len = 0;
1204         size = sizeof(hdr) + pp->cmd.reply_len;
1205         if (count < size)
1206                 size = count;
1207         rc = size;
1208         hdr.status = pp->cmd.status;
1209         hdr.reply_len = pp->cmd.reply_len;
1210         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1211                 return -EFAULT;
1212         size -= sizeof(hdr);
1213         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1214                 return -EFAULT;
1215         pp->busy = 0;
1216
1217         return rc;
1218 }
1219
1220
1221 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1222                                char __user *buf, size_t count)
1223 {
1224         /* Not implemented */
1225         msleep_interruptible(1000);
1226         return 0;
1227 }
1228
1229
1230 static ssize_t smu_read(struct file *file, char __user *buf,
1231                         size_t count, loff_t *ppos)
1232 {
1233         struct smu_private *pp = file->private_data;
1234
1235         if (pp->mode == smu_file_commands)
1236                 return smu_read_command(file, pp, buf, count);
1237         if (pp->mode == smu_file_events)
1238                 return smu_read_events(file, pp, buf, count);
1239
1240         return -EBADFD;
1241 }
1242
1243 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1244 {
1245         struct smu_private *pp = file->private_data;
1246         unsigned int mask = 0;
1247         unsigned long flags;
1248
1249         if (pp == 0)
1250                 return 0;
1251
1252         if (pp->mode == smu_file_commands) {
1253                 poll_wait(file, &pp->wait, wait);
1254
1255                 spin_lock_irqsave(&pp->lock, flags);
1256                 if (pp->busy && pp->cmd.status != 1)
1257                         mask |= POLLIN;
1258                 spin_unlock_irqrestore(&pp->lock, flags);
1259         } if (pp->mode == smu_file_events) {
1260                 /* Not yet implemented */
1261         }
1262         return mask;
1263 }
1264
1265 static int smu_release(struct inode *inode, struct file *file)
1266 {
1267         struct smu_private *pp = file->private_data;
1268         unsigned long flags;
1269         unsigned int busy;
1270
1271         if (pp == 0)
1272                 return 0;
1273
1274         file->private_data = NULL;
1275
1276         /* Mark file as closing to avoid races with new request */
1277         spin_lock_irqsave(&pp->lock, flags);
1278         pp->mode = smu_file_closing;
1279         busy = pp->busy;
1280
1281         /* Wait for any pending request to complete */
1282         if (busy && pp->cmd.status == 1) {
1283                 DECLARE_WAITQUEUE(wait, current);
1284
1285                 add_wait_queue(&pp->wait, &wait);
1286                 for (;;) {
1287                         set_current_state(TASK_UNINTERRUPTIBLE);
1288                         if (pp->cmd.status != 1)
1289                                 break;
1290                         spin_unlock_irqrestore(&pp->lock, flags);
1291                         schedule();
1292                         spin_lock_irqsave(&pp->lock, flags);
1293                 }
1294                 set_current_state(TASK_RUNNING);
1295                 remove_wait_queue(&pp->wait, &wait);
1296         }
1297         spin_unlock_irqrestore(&pp->lock, flags);
1298
1299         spin_lock_irqsave(&smu_clist_lock, flags);
1300         list_del(&pp->list);
1301         spin_unlock_irqrestore(&smu_clist_lock, flags);
1302         kfree(pp);
1303
1304         return 0;
1305 }
1306
1307
1308 static const struct file_operations smu_device_fops = {
1309         .llseek         = no_llseek,
1310         .read           = smu_read,
1311         .write          = smu_write,
1312         .poll           = smu_fpoll,
1313         .open           = smu_open,
1314         .release        = smu_release,
1315 };
1316
1317 static struct miscdevice pmu_device = {
1318         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1319 };
1320
1321 static int smu_device_init(void)
1322 {
1323         if (!smu)
1324                 return -ENODEV;
1325         if (misc_register(&pmu_device) < 0)
1326                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1327         return 0;
1328 }
1329 device_initcall(smu_device_init);