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/memblock.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/sched/signal.h>
  42
  43 #include <asm/byteorder.h>
  44 #include <asm/io.h>
  45 #include <asm/prom.h>
  46 #include <asm/machdep.h>
  47 #include <asm/pmac_feature.h>
  48 #include <asm/smu.h>
  49 #include <asm/sections.h>
  50 #include <linux/uaccess.h>
  51
  52 #define VERSION "0.7"
  53 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  54
  55 #undef DEBUG_SMU
  56
  57 #ifdef DEBUG_SMU
  58 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  59 #else
  60 #define DPRINTK(fmt, args...) do { } while (0)
  61 #endif
  62
  63 /*
  64  * This is the command buffer passed to the SMU hardware
  65  */
  66 #define SMU_MAX_DATA    254
  67
  68 struct smu_cmd_buf {
  69         u8 cmd;
  70         u8 length;
  71         u8 data[SMU_MAX_DATA];
  72 };
  73
  74 struct smu_device {
  75         spinlock_t              lock;
  76         struct device_node      *of_node;
  77         struct platform_device  *of_dev;
  78         int                     doorbell;       /* doorbell gpio */
  79         u32 __iomem             *db_buf;        /* doorbell buffer */
  80         struct device_node      *db_node;
  81         unsigned int            db_irq;
  82         int                     msg;
  83         struct device_node      *msg_node;
  84         unsigned int            msg_irq;
  85         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  86         u32                     cmd_buf_abs;    /* command buffer absolute */
  87         struct list_head        cmd_list;
  88         struct smu_cmd          *cmd_cur;       /* pending command */
  89         int                     broken_nap;
  90         struct list_head        cmd_i2c_list;
  91         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  92         struct timer_list       i2c_timer;
  93 };
  94
  95 /*
  96  * I don't think there will ever be more than one SMU, so
  97  * for now, just hard code that
  98  */
  99 static DEFINE_MUTEX(smu_mutex);
 100 static struct smu_device        *smu;
 101 static DEFINE_MUTEX(smu_part_access);
 102 static int smu_irq_inited;
 103 static unsigned long smu_cmdbuf_abs;
 104
 105 static void smu_i2c_retry(struct timer_list *t);
 106
 107 /*
 108  * SMU driver low level stuff
 109  */
 110
 111 static void smu_start_cmd(void)
 112 {
 113         unsigned long faddr, fend;
 114         struct smu_cmd *cmd;
 115
 116         if (list_empty(&smu->cmd_list))
 117                 return;
 118
 119         /* Fetch first command in queue */
 120         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 121         smu->cmd_cur = cmd;
 122         list_del(&cmd->link);
 123
 124         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 125                 cmd->data_len);
 126         DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf);
 127
 128         /* Fill the SMU command buffer */
 129         smu->cmd_buf->cmd = cmd->cmd;
 130         smu->cmd_buf->length = cmd->data_len;
 131         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 132
 133         /* Flush command and data to RAM */
 134         faddr = (unsigned long)smu->cmd_buf;
 135         fend = faddr + smu->cmd_buf->length + 2;
 136         flush_inval_dcache_range(faddr, fend);
 137
 138
 139         /* We also disable NAP mode for the duration of the command
 140          * on U3 based machines.
 141          * This is slightly racy as it can be written back to 1 by a sysctl
 142          * but that never happens in practice. There seem to be an issue with
 143          * U3 based machines such as the iMac G5 where napping for the
 144          * whole duration of the command prevents the SMU from fetching it
 145          * from memory. This might be related to the strange i2c based
 146          * mechanism the SMU uses to access memory.
 147          */
 148         if (smu->broken_nap)
 149                 powersave_nap = 0;
 150
 151         /* This isn't exactly a DMA mapping here, I suspect
 152          * the SMU is actually communicating with us via i2c to the
 153          * northbridge or the CPU to access RAM.
 154          */
 155         writel(smu->cmd_buf_abs, smu->db_buf);
 156
 157         /* Ring the SMU doorbell */
 158         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 159 }
 160
 161
 162 static irqreturn_t smu_db_intr(int irq, void *arg)
 163 {
 164         unsigned long flags;
 165         struct smu_cmd *cmd;
 166         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 167         void *misc = NULL;
 168         u8 gpio;
 169         int rc = 0;
 170
 171         /* SMU completed the command, well, we hope, let's make sure
 172          * of it
 173          */
 174         spin_lock_irqsave(&smu->lock, flags);
 175
 176         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 177         if ((gpio & 7) != 7) {
 178                 spin_unlock_irqrestore(&smu->lock, flags);
 179                 return IRQ_HANDLED;
 180         }
 181
 182         cmd = smu->cmd_cur;
 183         smu->cmd_cur = NULL;
 184         if (cmd == NULL)
 185                 goto bail;
 186
 187         if (rc == 0) {
 188                 unsigned long faddr;
 189                 int reply_len;
 190                 u8 ack;
 191
 192                 /* CPU might have brought back the cache line, so we need
 193                  * to flush again before peeking at the SMU response. We
 194                  * flush the entire buffer for now as we haven't read the
 195                  * reply length (it's only 2 cache lines anyway)
 196                  */
 197                 faddr = (unsigned long)smu->cmd_buf;
 198                 flush_inval_dcache_range(faddr, faddr + 256);
 199
 200                 /* Now check ack */
 201                 ack = (~cmd->cmd) & 0xff;
 202                 if (ack != smu->cmd_buf->cmd) {
 203                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 204                                 ack, smu->cmd_buf->cmd);
 205                         rc = -EIO;
 206                 }
 207                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 208                 DPRINTK("SMU: reply len: %d\n", reply_len);
 209                 if (reply_len > cmd->reply_len) {
 210                         printk(KERN_WARNING "SMU: reply buffer too small,"
 211                                "got %d bytes for a %d bytes buffer\n",
 212                                reply_len, cmd->reply_len);
 213                         reply_len = cmd->reply_len;
 214                 }
 215                 cmd->reply_len = reply_len;
 216                 if (cmd->reply_buf && reply_len)
 217                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 218         }
 219
 220         /* Now complete the command. Write status last in order as we lost
 221          * ownership of the command structure as soon as it's no longer -1
 222          */
 223         done = cmd->done;
 224         misc = cmd->misc;
 225         mb();
 226         cmd->status = rc;
 227
 228         /* Re-enable NAP mode */
 229         if (smu->broken_nap)
 230                 powersave_nap = 1;
 231  bail:
 232         /* Start next command if any */
 233         smu_start_cmd();
 234         spin_unlock_irqrestore(&smu->lock, flags);
 235
 236         /* Call command completion handler if any */
 237         if (done)
 238                 done(cmd, misc);
 239
 240         /* It's an edge interrupt, nothing to do */
 241         return IRQ_HANDLED;
 242 }
 243
 244
 245 static irqreturn_t smu_msg_intr(int irq, void *arg)
 246 {
 247         /* I don't quite know what to do with this one, we seem to never
 248          * receive it, so I suspect we have to arm it someway in the SMU
 249          * to start getting events that way.
 250          */
 251
 252         printk(KERN_INFO "SMU: message interrupt !\n");
 253
 254         /* It's an edge interrupt, nothing to do */
 255         return IRQ_HANDLED;
 256 }
 257
 258
 259 /*
 260  * Queued command management.
 261  *
 262  */
 263
 264 int smu_queue_cmd(struct smu_cmd *cmd)
 265 {
 266         unsigned long flags;
 267
 268         if (smu == NULL)
 269                 return -ENODEV;
 270         if (cmd->data_len > SMU_MAX_DATA ||
 271             cmd->reply_len > SMU_MAX_DATA)
 272                 return -EINVAL;
 273
 274         cmd->status = 1;
 275         spin_lock_irqsave(&smu->lock, flags);
 276         list_add_tail(&cmd->link, &smu->cmd_list);
 277         if (smu->cmd_cur == NULL)
 278                 smu_start_cmd();
 279         spin_unlock_irqrestore(&smu->lock, flags);
 280
 281         /* Workaround for early calls when irq isn't available */
 282         if (!smu_irq_inited || !smu->db_irq)
 283                 smu_spinwait_cmd(cmd);
 284
 285         return 0;
 286 }
 287 EXPORT_SYMBOL(smu_queue_cmd);
 288
 289
 290 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 291                      unsigned int data_len,
 292                      void (*done)(struct smu_cmd *cmd, void *misc),
 293                      void *misc, ...)
 294 {
 295         struct smu_cmd *cmd = &scmd->cmd;
 296         va_list list;
 297         int i;
 298
 299         if (data_len > sizeof(scmd->buffer))
 300                 return -EINVAL;
 301
 302         memset(scmd, 0, sizeof(*scmd));
 303         cmd->cmd = command;
 304         cmd->data_len = data_len;
 305         cmd->data_buf = scmd->buffer;
 306         cmd->reply_len = sizeof(scmd->buffer);
 307         cmd->reply_buf = scmd->buffer;
 308         cmd->done = done;
 309         cmd->misc = misc;
 310
 311         va_start(list, misc);
 312         for (i = 0; i < data_len; ++i)
 313                 scmd->buffer[i] = (u8)va_arg(list, int);
 314         va_end(list);
 315
 316         return smu_queue_cmd(cmd);
 317 }
 318 EXPORT_SYMBOL(smu_queue_simple);
 319
 320
 321 void smu_poll(void)
 322 {
 323         u8 gpio;
 324
 325         if (smu == NULL)
 326                 return;
 327
 328         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 329         if ((gpio & 7) == 7)
 330                 smu_db_intr(smu->db_irq, smu);
 331 }
 332 EXPORT_SYMBOL(smu_poll);
 333
 334
 335 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 336 {
 337         struct completion *comp = misc;
 338
 339         complete(comp);
 340 }
 341 EXPORT_SYMBOL(smu_done_complete);
 342
 343
 344 void smu_spinwait_cmd(struct smu_cmd *cmd)
 345 {
 346         while(cmd->status == 1)
 347                 smu_poll();
 348 }
 349 EXPORT_SYMBOL(smu_spinwait_cmd);
 350
 351
 352 /* RTC low level commands */
 353 static inline int bcd2hex (int n)
 354 {
 355         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 356 }
 357
 358
 359 static inline int hex2bcd (int n)
 360 {
 361         return ((n / 10) << 4) + (n % 10);
 362 }
 363
 364
 365 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 366                                         struct rtc_time *time)
 367 {
 368         cmd_buf->cmd = 0x8e;
 369         cmd_buf->length = 8;
 370         cmd_buf->data[0] = 0x80;
 371         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 372         cmd_buf->data[2] = hex2bcd(time->tm_min);
 373         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 374         cmd_buf->data[4] = time->tm_wday;
 375         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 376         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 377         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 378 }
 379
 380
 381 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 382 {
 383         struct smu_simple_cmd cmd;
 384         int rc;
 385
 386         if (smu == NULL)
 387                 return -ENODEV;
 388
 389         memset(time, 0, sizeof(struct rtc_time));
 390         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 391                               SMU_CMD_RTC_GET_DATETIME);
 392         if (rc)
 393                 return rc;
 394         smu_spinwait_simple(&cmd);
 395
 396         time->tm_sec = bcd2hex(cmd.buffer[0]);
 397         time->tm_min = bcd2hex(cmd.buffer[1]);
 398         time->tm_hour = bcd2hex(cmd.buffer[2]);
 399         time->tm_wday = bcd2hex(cmd.buffer[3]);
 400         time->tm_mday = bcd2hex(cmd.buffer[4]);
 401         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 402         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 403
 404         return 0;
 405 }
 406
 407
 408 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 409 {
 410         struct smu_simple_cmd cmd;
 411         int rc;
 412
 413         if (smu == NULL)
 414                 return -ENODEV;
 415
 416         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 417                               SMU_CMD_RTC_SET_DATETIME,
 418                               hex2bcd(time->tm_sec),
 419                               hex2bcd(time->tm_min),
 420                               hex2bcd(time->tm_hour),
 421                               time->tm_wday,
 422                               hex2bcd(time->tm_mday),
 423                               hex2bcd(time->tm_mon) + 1,
 424                               hex2bcd(time->tm_year - 100));
 425         if (rc)
 426                 return rc;
 427         smu_spinwait_simple(&cmd);
 428
 429         return 0;
 430 }
 431
 432
 433 void smu_shutdown(void)
 434 {
 435         struct smu_simple_cmd cmd;
 436
 437         if (smu == NULL)
 438                 return;
 439
 440         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 441                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 442                 return;
 443         smu_spinwait_simple(&cmd);
 444         for (;;)
 445                 ;
 446 }
 447
 448
 449 void smu_restart(void)
 450 {
 451         struct smu_simple_cmd cmd;
 452
 453         if (smu == NULL)
 454                 return;
 455
 456         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 457                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 458                 return;
 459         smu_spinwait_simple(&cmd);
 460         for (;;)
 461                 ;
 462 }
 463
 464
 465 int smu_present(void)
 466 {
 467         return smu != NULL;
 468 }
 469 EXPORT_SYMBOL(smu_present);
 470
 471
 472 int __init smu_init (void)
 473 {
 474         struct device_node *np;
 475         const u32 *data;
 476         int ret = 0;
 477
 478         np = of_find_node_by_type(NULL, "smu");
 479         if (np == NULL)
 480                 return -ENODEV;
 481
 482         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 483
 484         /*
 485          * SMU based G5s need some memory below 2Gb. Thankfully this is
 486          * called at a time where memblock is still available.
 487          */
 488         smu_cmdbuf_abs = memblock_alloc_base(4096, 4096, 0x80000000UL);
 489         if (smu_cmdbuf_abs == 0) {
 490                 printk(KERN_ERR "SMU: Command buffer allocation failed !\n");
 491                 ret = -EINVAL;
 492                 goto fail_np;
 493         }
 494
 495         smu = memblock_alloc(sizeof(struct smu_device), SMP_CACHE_BYTES);
 496
 497         spin_lock_init(&smu->lock);
 498         INIT_LIST_HEAD(&smu->cmd_list);
 499         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 500         smu->of_node = np;
 501         smu->db_irq = 0;
 502         smu->msg_irq = 0;
 503
 504         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 505          * 32 bits value safely
 506          */
 507         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 508         smu->cmd_buf = __va(smu_cmdbuf_abs);
 509
 510         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 511         if (smu->db_node == NULL) {
 512                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 513                 ret = -ENXIO;
 514                 goto fail_bootmem;
 515         }
 516         data = of_get_property(smu->db_node, "reg", NULL);
 517         if (data == NULL) {
 518                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 519                 ret = -ENXIO;
 520                 goto fail_db_node;
 521         }
 522
 523         /* Current setup has one doorbell GPIO that does both doorbell
 524          * and ack. GPIOs are at 0x50, best would be to find that out
 525          * in the device-tree though.
 526          */
 527         smu->doorbell = *data;
 528         if (smu->doorbell < 0x50)
 529                 smu->doorbell += 0x50;
 530
 531         /* Now look for the smu-interrupt GPIO */
 532         do {
 533                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 534                 if (smu->msg_node == NULL)
 535                         break;
 536                 data = of_get_property(smu->msg_node, "reg", NULL);
 537                 if (data == NULL) {
 538                         of_node_put(smu->msg_node);
 539                         smu->msg_node = NULL;
 540                         break;
 541                 }
 542                 smu->msg = *data;
 543                 if (smu->msg < 0x50)
 544                         smu->msg += 0x50;
 545         } while(0);
 546
 547         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 548          * device-tree entry giving the address. Best would probably to use
 549          * an offset for K2 base though, but let's do it that way for now.
 550          */
 551         smu->db_buf = ioremap(0x8000860c, 0x1000);
 552         if (smu->db_buf == NULL) {
 553                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 554                 ret = -ENXIO;
 555                 goto fail_msg_node;
 556         }
 557
 558         /* U3 has an issue with NAP mode when issuing SMU commands */
 559         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 560         if (smu->broken_nap)
 561                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 562
 563         sys_ctrler = SYS_CTRLER_SMU;
 564         return 0;
 565
 566 fail_msg_node:
 567         of_node_put(smu->msg_node);
 568 fail_db_node:
 569         of_node_put(smu->db_node);
 570 fail_bootmem:
 571         memblock_free(__pa(smu), sizeof(struct smu_device));
 572         smu = NULL;
 573 fail_np:
 574         of_node_put(np);
 575         return ret;
 576 }
 577
 578
 579 static int smu_late_init(void)
 580 {
 581         if (!smu)
 582                 return 0;
 583
 584         timer_setup(&smu->i2c_timer, smu_i2c_retry, 0);
 585
 586         if (smu->db_node) {
 587                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 588                 if (!smu->db_irq)
 589                         printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 590                                smu->db_node);
 591         }
 592         if (smu->msg_node) {
 593                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 594                 if (!smu->msg_irq)
 595                         printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 596                                smu->msg_node);
 597         }
 598
 599         /*
 600          * Try to request the interrupts
 601          */
 602
 603         if (smu->db_irq) {
 604                 if (request_irq(smu->db_irq, smu_db_intr,
 605                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 606                         printk(KERN_WARNING "SMU: can't "
 607                                "request interrupt %d\n",
 608                                smu->db_irq);
 609                         smu->db_irq = 0;
 610                 }
 611         }
 612
 613         if (smu->msg_irq) {
 614                 if (request_irq(smu->msg_irq, smu_msg_intr,
 615                                 IRQF_SHARED, "SMU message", smu) < 0) {
 616                         printk(KERN_WARNING "SMU: can't "
 617                                "request interrupt %d\n",
 618                                smu->msg_irq);
 619                         smu->msg_irq = 0;
 620                 }
 621         }
 622
 623         smu_irq_inited = 1;
 624         return 0;
 625 }
 626 /* This has to be before arch_initcall as the low i2c stuff relies on the
 627  * above having been done before we reach arch_initcalls
 628  */
 629 core_initcall(smu_late_init);
 630
 631 /*
 632  * sysfs visibility
 633  */
 634
 635 static void smu_expose_childs(struct work_struct *unused)
 636 {
 637         struct device_node *np;
 638
 639         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 640                 if (of_device_is_compatible(np, "smu-sensors"))
 641                         of_platform_device_create(np, "smu-sensors",
 642                                                   &smu->of_dev->dev);
 643 }
 644
 645 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 646
 647 static int smu_platform_probe(struct platform_device* dev)
 648 {
 649         if (!smu)
 650                 return -ENODEV;
 651         smu->of_dev = dev;
 652
 653         /*
 654          * Ok, we are matched, now expose all i2c busses. We have to defer
 655          * that unfortunately or it would deadlock inside the device model
 656          */
 657         schedule_work(&smu_expose_childs_work);
 658
 659         return 0;
 660 }
 661
 662 static const struct of_device_id smu_platform_match[] =
 663 {
 664         {
 665                 .type           = "smu",
 666         },
 667         {},
 668 };
 669
 670 static struct platform_driver smu_of_platform_driver =
 671 {
 672         .driver = {
 673                 .name = "smu",
 674                 .of_match_table = smu_platform_match,
 675         },
 676         .probe          = smu_platform_probe,
 677 };
 678
 679 static int __init smu_init_sysfs(void)
 680 {
 681         /*
 682          * For now, we don't power manage machines with an SMU chip,
 683          * I'm a bit too far from figuring out how that works with those
 684          * new chipsets, but that will come back and bite us
 685          */
 686         platform_driver_register(&smu_of_platform_driver);
 687         return 0;
 688 }
 689
 690 device_initcall(smu_init_sysfs);
 691
 692 struct platform_device *smu_get_ofdev(void)
 693 {
 694         if (!smu)
 695                 return NULL;
 696         return smu->of_dev;
 697 }
 698
 699 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 700
 701 /*
 702  * i2c interface
 703  */
 704
 705 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 706 {
 707         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 708         void *misc = cmd->misc;
 709         unsigned long flags;
 710
 711         /* Check for read case */
 712         if (!fail && cmd->read) {
 713                 if (cmd->pdata[0] < 1)
 714                         fail = 1;
 715                 else
 716                         memcpy(cmd->info.data, &cmd->pdata[1],
 717                                cmd->info.datalen);
 718         }
 719
 720         DPRINTK("SMU: completing, success: %d\n", !fail);
 721
 722         /* Update status and mark no pending i2c command with lock
 723          * held so nobody comes in while we dequeue an eventual
 724          * pending next i2c command
 725          */
 726         spin_lock_irqsave(&smu->lock, flags);
 727         smu->cmd_i2c_cur = NULL;
 728         wmb();
 729         cmd->status = fail ? -EIO : 0;
 730
 731         /* Is there another i2c command waiting ? */
 732         if (!list_empty(&smu->cmd_i2c_list)) {
 733                 struct smu_i2c_cmd *newcmd;
 734
 735                 /* Fetch it, new current, remove from list */
 736                 newcmd = list_entry(smu->cmd_i2c_list.next,
 737                                     struct smu_i2c_cmd, link);
 738                 smu->cmd_i2c_cur = newcmd;
 739                 list_del(&cmd->link);
 740
 741                 /* Queue with low level smu */
 742                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 743                 if (smu->cmd_cur == NULL)
 744                         smu_start_cmd();
 745         }
 746         spin_unlock_irqrestore(&smu->lock, flags);
 747
 748         /* Call command completion handler if any */
 749         if (done)
 750                 done(cmd, misc);
 751
 752 }
 753
 754
 755 static void smu_i2c_retry(struct timer_list *unused)
 756 {
 757         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 758
 759         DPRINTK("SMU: i2c failure, requeuing...\n");
 760
 761         /* requeue command simply by resetting reply_len */
 762         cmd->pdata[0] = 0xff;
 763         cmd->scmd.reply_len = sizeof(cmd->pdata);
 764         smu_queue_cmd(&cmd->scmd);
 765 }
 766
 767
 768 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 769 {
 770         struct smu_i2c_cmd      *cmd = misc;
 771         int                     fail = 0;
 772
 773         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 774                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 775
 776         /* Check for possible status */
 777         if (scmd->status < 0)
 778                 fail = 1;
 779         else if (cmd->read) {
 780                 if (cmd->stage == 0)
 781                         fail = cmd->pdata[0] != 0;
 782                 else
 783                         fail = cmd->pdata[0] >= 0x80;
 784         } else {
 785                 fail = cmd->pdata[0] != 0;
 786         }
 787
 788         /* Handle failures by requeuing command, after 5ms interval
 789          */
 790         if (fail && --cmd->retries > 0) {
 791                 DPRINTK("SMU: i2c failure, starting timer...\n");
 792                 BUG_ON(cmd != smu->cmd_i2c_cur);
 793                 if (!smu_irq_inited) {
 794                         mdelay(5);
 795                         smu_i2c_retry(NULL);
 796                         return;
 797                 }
 798                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 799                 return;
 800         }
 801
 802         /* If failure or stage 1, command is complete */
 803         if (fail || cmd->stage != 0) {
 804                 smu_i2c_complete_command(cmd, fail);
 805                 return;
 806         }
 807
 808         DPRINTK("SMU: going to stage 1\n");
 809
 810         /* Ok, initial command complete, now poll status */
 811         scmd->reply_buf = cmd->pdata;
 812         scmd->reply_len = sizeof(cmd->pdata);
 813         scmd->data_buf = cmd->pdata;
 814         scmd->data_len = 1;
 815         cmd->pdata[0] = 0;
 816         cmd->stage = 1;
 817         cmd->retries = 20;
 818         smu_queue_cmd(scmd);
 819 }
 820
 821
 822 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 823 {
 824         unsigned long flags;
 825
 826         if (smu == NULL)
 827                 return -ENODEV;
 828
 829         /* Fill most fields of scmd */
 830         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 831         cmd->scmd.done = smu_i2c_low_completion;
 832         cmd->scmd.misc = cmd;
 833         cmd->scmd.reply_buf = cmd->pdata;
 834         cmd->scmd.reply_len = sizeof(cmd->pdata);
 835         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 836         cmd->scmd.status = 1;
 837         cmd->stage = 0;
 838         cmd->pdata[0] = 0xff;
 839         cmd->retries = 20;
 840         cmd->status = 1;
 841
 842         /* Check transfer type, sanitize some "info" fields
 843          * based on transfer type and do more checking
 844          */
 845         cmd->info.caddr = cmd->info.devaddr;
 846         cmd->read = cmd->info.devaddr & 0x01;
 847         switch(cmd->info.type) {
 848         case SMU_I2C_TRANSFER_SIMPLE:
 849                 memset(&cmd->info.sublen, 0, 4);
 850                 break;
 851         case SMU_I2C_TRANSFER_COMBINED:
 852                 cmd->info.devaddr &= 0xfe;
 853         case SMU_I2C_TRANSFER_STDSUB:
 854                 if (cmd->info.sublen > 3)
 855                         return -EINVAL;
 856                 break;
 857         default:
 858                 return -EINVAL;
 859         }
 860
 861         /* Finish setting up command based on transfer direction
 862          */
 863         if (cmd->read) {
 864                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 865                         return -EINVAL;
 866                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 867                 cmd->scmd.data_len = 9;
 868         } else {
 869                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 870                         return -EINVAL;
 871                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 872         }
 873
 874         DPRINTK("SMU: i2c enqueuing command\n");
 875         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 876                 cmd->read ? "read" : "write", cmd->info.datalen,
 877                 cmd->info.bus, cmd->info.caddr,
 878                 cmd->info.subaddr[0], cmd->info.type);
 879
 880
 881         /* Enqueue command in i2c list, and if empty, enqueue also in
 882          * main command list
 883          */
 884         spin_lock_irqsave(&smu->lock, flags);
 885         if (smu->cmd_i2c_cur == NULL) {
 886                 smu->cmd_i2c_cur = cmd;
 887                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 888                 if (smu->cmd_cur == NULL)
 889                         smu_start_cmd();
 890         } else
 891                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 892         spin_unlock_irqrestore(&smu->lock, flags);
 893
 894         return 0;
 895 }
 896
 897 /*
 898  * Handling of "partitions"
 899  */
 900
 901 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 902 {
 903         DECLARE_COMPLETION_ONSTACK(comp);
 904         unsigned int chunk;
 905         struct smu_cmd cmd;
 906         int rc;
 907         u8 params[8];
 908
 909         /* We currently use a chunk size of 0xe. We could check the
 910          * SMU firmware version and use bigger sizes though
 911          */
 912         chunk = 0xe;
 913
 914         while (len) {
 915                 unsigned int clen = min(len, chunk);
 916
 917                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 918                 cmd.data_len = 7;
 919                 cmd.data_buf = params;
 920                 cmd.reply_len = chunk;
 921                 cmd.reply_buf = dest;
 922                 cmd.done = smu_done_complete;
 923                 cmd.misc = &comp;
 924                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 925                 params[1] = 0x4;
 926                 *((u32 *)&params[2]) = addr;
 927                 params[6] = clen;
 928
 929                 rc = smu_queue_cmd(&cmd);
 930                 if (rc)
 931                         return rc;
 932                 wait_for_completion(&comp);
 933                 if (cmd.status != 0)
 934                         return rc;
 935                 if (cmd.reply_len != clen) {
 936                         printk(KERN_DEBUG "SMU: short read in "
 937                                "smu_read_datablock, got: %d, want: %d\n",
 938                                cmd.reply_len, clen);
 939                         return -EIO;
 940                 }
 941                 len -= clen;
 942                 addr += clen;
 943                 dest += clen;
 944         }
 945         return 0;
 946 }
 947
 948 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 949 {
 950         DECLARE_COMPLETION_ONSTACK(comp);
 951         struct smu_simple_cmd cmd;
 952         unsigned int addr, len, tlen;
 953         struct smu_sdbp_header *hdr;
 954         struct property *prop;
 955
 956         /* First query the partition info */
 957         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 958         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 959                          smu_done_complete, &comp,
 960                          SMU_CMD_PARTITION_LATEST, id);
 961         wait_for_completion(&comp);
 962         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 963                 cmd.cmd.status, cmd.cmd.reply_len);
 964
 965         /* Partition doesn't exist (or other error) */
 966         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 967                 return NULL;
 968
 969         /* Fetch address and length from reply */
 970         addr = *((u16 *)cmd.buffer);
 971         len = cmd.buffer[3] << 2;
 972         /* Calucluate total length to allocate, including the 17 bytes
 973          * for "sdb-partition-XX" that we append at the end of the buffer
 974          */
 975         tlen = sizeof(struct property) + len + 18;
 976
 977         prop = kzalloc(tlen, GFP_KERNEL);
 978         if (prop == NULL)
 979                 return NULL;
 980         hdr = (struct smu_sdbp_header *)(prop + 1);
 981         prop->name = ((char *)prop) + tlen - 18;
 982         sprintf(prop->name, "sdb-partition-%02x", id);
 983         prop->length = len;
 984         prop->value = hdr;
 985         prop->next = NULL;
 986
 987         /* Read the datablock */
 988         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 989                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 990                        "partition %02x !\n", id);
 991                 goto failure;
 992         }
 993
 994         /* Got it, check a few things and create the property */
 995         if (hdr->id != id) {
 996                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 997                        "%02x !\n", id, hdr->id);
 998                 goto failure;
 999         }
1000         if (of_add_property(smu->of_node, prop)) {
1001                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1002                        "property !\n", id);
1003                 goto failure;
1004         }
1005
1006         return hdr;
1007  failure:
1008         kfree(prop);
1009         return NULL;
1010 }
1011
1012 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1013  * when interruptible is 1
1014  */
1015 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1016                 unsigned int *size, int interruptible)
1017 {
1018         char pname[32];
1019         const struct smu_sdbp_header *part;
1020
1021         if (!smu)
1022                 return NULL;
1023
1024         sprintf(pname, "sdb-partition-%02x", id);
1025
1026         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1027
1028         if (interruptible) {
1029                 int rc;
1030                 rc = mutex_lock_interruptible(&smu_part_access);
1031                 if (rc)
1032                         return ERR_PTR(rc);
1033         } else
1034                 mutex_lock(&smu_part_access);
1035
1036         part = of_get_property(smu->of_node, pname, size);
1037         if (part == NULL) {
1038                 DPRINTK("trying to extract from SMU ...\n");
1039                 part = smu_create_sdb_partition(id);
1040                 if (part != NULL && size)
1041                         *size = part->len << 2;
1042         }
1043         mutex_unlock(&smu_part_access);
1044         return part;
1045 }
1046
1047 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1048 {
1049         return __smu_get_sdb_partition(id, size, 0);
1050 }
1051 EXPORT_SYMBOL(smu_get_sdb_partition);
1052
1053
1054 /*
1055  * Userland driver interface
1056  */
1057
1058
1059 static LIST_HEAD(smu_clist);
1060 static DEFINE_SPINLOCK(smu_clist_lock);
1061
1062 enum smu_file_mode {
1063         smu_file_commands,
1064         smu_file_events,
1065         smu_file_closing
1066 };
1067
1068 struct smu_private
1069 {
1070         struct list_head        list;
1071         enum smu_file_mode      mode;
1072         int                     busy;
1073         struct smu_cmd          cmd;
1074         spinlock_t              lock;
1075         wait_queue_head_t       wait;
1076         u8                      buffer[SMU_MAX_DATA];
1077 };
1078
1079
1080 static int smu_open(struct inode *inode, struct file *file)
1081 {
1082         struct smu_private *pp;
1083         unsigned long flags;
1084
1085         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1086         if (pp == 0)
1087                 return -ENOMEM;
1088         spin_lock_init(&pp->lock);
1089         pp->mode = smu_file_commands;
1090         init_waitqueue_head(&pp->wait);
1091
1092         mutex_lock(&smu_mutex);
1093         spin_lock_irqsave(&smu_clist_lock, flags);
1094         list_add(&pp->list, &smu_clist);
1095         spin_unlock_irqrestore(&smu_clist_lock, flags);
1096         file->private_data = pp;
1097         mutex_unlock(&smu_mutex);
1098
1099         return 0;
1100 }
1101
1102
1103 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1104 {
1105         struct smu_private *pp = misc;
1106
1107         wake_up_all(&pp->wait);
1108 }
1109
1110
1111 static ssize_t smu_write(struct file *file, const char __user *buf,
1112                          size_t count, loff_t *ppos)
1113 {
1114         struct smu_private *pp = file->private_data;
1115         unsigned long flags;
1116         struct smu_user_cmd_hdr hdr;
1117         int rc = 0;
1118
1119         if (pp->busy)
1120                 return -EBUSY;
1121         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1122                 return -EFAULT;
1123         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1124                 pp->mode = smu_file_events;
1125                 return 0;
1126         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1127                 const struct smu_sdbp_header *part;
1128                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1129                 if (part == NULL)
1130                         return -EINVAL;
1131                 else if (IS_ERR(part))
1132                         return PTR_ERR(part);
1133                 return 0;
1134         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1135                 return -EINVAL;
1136         else if (pp->mode != smu_file_commands)
1137                 return -EBADFD;
1138         else if (hdr.data_len > SMU_MAX_DATA)
1139                 return -EINVAL;
1140
1141         spin_lock_irqsave(&pp->lock, flags);
1142         if (pp->busy) {
1143                 spin_unlock_irqrestore(&pp->lock, flags);
1144                 return -EBUSY;
1145         }
1146         pp->busy = 1;
1147         pp->cmd.status = 1;
1148         spin_unlock_irqrestore(&pp->lock, flags);
1149
1150         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1151                 pp->busy = 0;
1152                 return -EFAULT;
1153         }
1154
1155         pp->cmd.cmd = hdr.cmd;
1156         pp->cmd.data_len = hdr.data_len;
1157         pp->cmd.reply_len = SMU_MAX_DATA;
1158         pp->cmd.data_buf = pp->buffer;
1159         pp->cmd.reply_buf = pp->buffer;
1160         pp->cmd.done = smu_user_cmd_done;
1161         pp->cmd.misc = pp;
1162         rc = smu_queue_cmd(&pp->cmd);
1163         if (rc < 0)
1164                 return rc;
1165         return count;
1166 }
1167
1168
1169 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1170                                 char __user *buf, size_t count)
1171 {
1172         DECLARE_WAITQUEUE(wait, current);
1173         struct smu_user_reply_hdr hdr;
1174         unsigned long flags;
1175         int size, rc = 0;
1176
1177         if (!pp->busy)
1178                 return 0;
1179         if (count < sizeof(struct smu_user_reply_hdr))
1180                 return -EOVERFLOW;
1181         spin_lock_irqsave(&pp->lock, flags);
1182         if (pp->cmd.status == 1) {
1183                 if (file->f_flags & O_NONBLOCK) {
1184                         spin_unlock_irqrestore(&pp->lock, flags);
1185                         return -EAGAIN;
1186                 }
1187                 add_wait_queue(&pp->wait, &wait);
1188                 for (;;) {
1189                         set_current_state(TASK_INTERRUPTIBLE);
1190                         rc = 0;
1191                         if (pp->cmd.status != 1)
1192                                 break;
1193                         rc = -ERESTARTSYS;
1194                         if (signal_pending(current))
1195                                 break;
1196                         spin_unlock_irqrestore(&pp->lock, flags);
1197                         schedule();
1198                         spin_lock_irqsave(&pp->lock, flags);
1199                 }
1200                 set_current_state(TASK_RUNNING);
1201                 remove_wait_queue(&pp->wait, &wait);
1202         }
1203         spin_unlock_irqrestore(&pp->lock, flags);
1204         if (rc)
1205                 return rc;
1206         if (pp->cmd.status != 0)
1207                 pp->cmd.reply_len = 0;
1208         size = sizeof(hdr) + pp->cmd.reply_len;
1209         if (count < size)
1210                 size = count;
1211         rc = size;
1212         hdr.status = pp->cmd.status;
1213         hdr.reply_len = pp->cmd.reply_len;
1214         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1215                 return -EFAULT;
1216         size -= sizeof(hdr);
1217         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1218                 return -EFAULT;
1219         pp->busy = 0;
1220
1221         return rc;
1222 }
1223
1224
1225 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1226                                char __user *buf, size_t count)
1227 {
1228         /* Not implemented */
1229         msleep_interruptible(1000);
1230         return 0;
1231 }
1232
1233
1234 static ssize_t smu_read(struct file *file, char __user *buf,
1235                         size_t count, loff_t *ppos)
1236 {
1237         struct smu_private *pp = file->private_data;
1238
1239         if (pp->mode == smu_file_commands)
1240                 return smu_read_command(file, pp, buf, count);
1241         if (pp->mode == smu_file_events)
1242                 return smu_read_events(file, pp, buf, count);
1243
1244         return -EBADFD;
1245 }
1246
1247 static __poll_t smu_fpoll(struct file *file, poll_table *wait)
1248 {
1249         struct smu_private *pp = file->private_data;
1250         __poll_t mask = 0;
1251         unsigned long flags;
1252
1253         if (pp == 0)
1254                 return 0;
1255
1256         if (pp->mode == smu_file_commands) {
1257                 poll_wait(file, &pp->wait, wait);
1258
1259                 spin_lock_irqsave(&pp->lock, flags);
1260                 if (pp->busy && pp->cmd.status != 1)
1261                         mask |= EPOLLIN;
1262                 spin_unlock_irqrestore(&pp->lock, flags);
1263         }
1264         if (pp->mode == smu_file_events) {
1265                 /* Not yet implemented */
1266         }
1267         return mask;
1268 }
1269
1270 static int smu_release(struct inode *inode, struct file *file)
1271 {
1272         struct smu_private *pp = file->private_data;
1273         unsigned long flags;
1274         unsigned int busy;
1275
1276         if (pp == 0)
1277                 return 0;
1278
1279         file->private_data = NULL;
1280
1281         /* Mark file as closing to avoid races with new request */
1282         spin_lock_irqsave(&pp->lock, flags);
1283         pp->mode = smu_file_closing;
1284         busy = pp->busy;
1285
1286         /* Wait for any pending request to complete */
1287         if (busy && pp->cmd.status == 1) {
1288                 DECLARE_WAITQUEUE(wait, current);
1289
1290                 add_wait_queue(&pp->wait, &wait);
1291                 for (;;) {
1292                         set_current_state(TASK_UNINTERRUPTIBLE);
1293                         if (pp->cmd.status != 1)
1294                                 break;
1295                         spin_unlock_irqrestore(&pp->lock, flags);
1296                         schedule();
1297                         spin_lock_irqsave(&pp->lock, flags);
1298                 }
1299                 set_current_state(TASK_RUNNING);
1300                 remove_wait_queue(&pp->wait, &wait);
1301         }
1302         spin_unlock_irqrestore(&pp->lock, flags);
1303
1304         spin_lock_irqsave(&smu_clist_lock, flags);
1305         list_del(&pp->list);
1306         spin_unlock_irqrestore(&smu_clist_lock, flags);
1307         kfree(pp);
1308
1309         return 0;
1310 }
1311
1312
1313 static const struct file_operations smu_device_fops = {
1314         .llseek         = no_llseek,
1315         .read           = smu_read,
1316         .write          = smu_write,
1317         .poll           = smu_fpoll,
1318         .open           = smu_open,
1319         .release        = smu_release,
1320 };
1321
1322 static struct miscdevice pmu_device = {
1323         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1324 };
1325
1326 static int smu_device_init(void)
1327 {
1328         if (!smu)
1329                 return -ENODEV;
1330         if (misc_register(&pmu_device) < 0)
1331                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1332         return 0;
1333 }
1334 device_initcall(smu_device_init);