drivers/macintosh/smu.c

   1 /*
   2  * PowerMac G5 SMU driver
   3  *
   4  * Copyright 2004 J. Mayer <l_indien@magic.fr>
   5  * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   6  *
   7  * Released under the term of the GNU GPL v2.
   8  */
   9
  10 /*
  11  * TODO:
  12  *  - maybe add timeout to commands ?
  13  *  - blocking version of time functions
  14  *  - polling version of i2c commands (including timer that works with
  15  *    interrupts off)
  16  *  - maybe avoid some data copies with i2c by directly using the smu cmd
  17  *    buffer and a lower level internal interface
  18  *  - understand SMU -> CPU events and implement reception of them via
  19  *    the userland interface
  20  */
  21
  22 #include <linux/types.h>
  23 #include <linux/kernel.h>
  24 #include <linux/device.h>
  25 #include <linux/dmapool.h>
  26 #include <linux/bootmem.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/highmem.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/rtc.h>
  32 #include <linux/completion.h>
  33 #include <linux/miscdevice.h>
  34 #include <linux/delay.h>
  35 #include <linux/sysdev.h>
  36 #include <linux/poll.h>
  37 #include <linux/mutex.h>
  38 #include <linux/of_device.h>
  39 #include <linux/of_platform.h>
  40 #include <linux/slab.h>
  41
  42 #include <asm/byteorder.h>
  43 #include <asm/io.h>
  44 #include <asm/prom.h>
  45 #include <asm/machdep.h>
  46 #include <asm/pmac_feature.h>
  47 #include <asm/smu.h>
  48 #include <asm/sections.h>
  49 #include <asm/abs_addr.h>
  50 #include <asm/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
 104 static void smu_i2c_retry(unsigned long data);
 105
 106 /*
 107  * SMU driver low level stuff
 108  */
 109
 110 static void smu_start_cmd(void)
 111 {
 112         unsigned long faddr, fend;
 113         struct smu_cmd *cmd;
 114
 115         if (list_empty(&smu->cmd_list))
 116                 return;
 117
 118         /* Fetch first command in queue */
 119         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 120         smu->cmd_cur = cmd;
 121         list_del(&cmd->link);
 122
 123         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 124                 cmd->data_len);
 125         DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 126                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 127                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 128                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 129                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 130
 131         /* Fill the SMU command buffer */
 132         smu->cmd_buf->cmd = cmd->cmd;
 133         smu->cmd_buf->length = cmd->data_len;
 134         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 135
 136         /* Flush command and data to RAM */
 137         faddr = (unsigned long)smu->cmd_buf;
 138         fend = faddr + smu->cmd_buf->length + 2;
 139         flush_inval_dcache_range(faddr, fend);
 140
 141
 142         /* We also disable NAP mode for the duration of the command
 143          * on U3 based machines.
 144          * This is slightly racy as it can be written back to 1 by a sysctl
 145          * but that never happens in practice. There seem to be an issue with
 146          * U3 based machines such as the iMac G5 where napping for the
 147          * whole duration of the command prevents the SMU from fetching it
 148          * from memory. This might be related to the strange i2c based
 149          * mechanism the SMU uses to access memory.
 150          */
 151         if (smu->broken_nap)
 152                 powersave_nap = 0;
 153
 154         /* This isn't exactly a DMA mapping here, I suspect
 155          * the SMU is actually communicating with us via i2c to the
 156          * northbridge or the CPU to access RAM.
 157          */
 158         writel(smu->cmd_buf_abs, smu->db_buf);
 159
 160         /* Ring the SMU doorbell */
 161         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 162 }
 163
 164
 165 static irqreturn_t smu_db_intr(int irq, void *arg)
 166 {
 167         unsigned long flags;
 168         struct smu_cmd *cmd;
 169         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 170         void *misc = NULL;
 171         u8 gpio;
 172         int rc = 0;
 173
 174         /* SMU completed the command, well, we hope, let's make sure
 175          * of it
 176          */
 177         spin_lock_irqsave(&smu->lock, flags);
 178
 179         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 180         if ((gpio & 7) != 7) {
 181                 spin_unlock_irqrestore(&smu->lock, flags);
 182                 return IRQ_HANDLED;
 183         }
 184
 185         cmd = smu->cmd_cur;
 186         smu->cmd_cur = NULL;
 187         if (cmd == NULL)
 188                 goto bail;
 189
 190         if (rc == 0) {
 191                 unsigned long faddr;
 192                 int reply_len;
 193                 u8 ack;
 194
 195                 /* CPU might have brought back the cache line, so we need
 196                  * to flush again before peeking at the SMU response. We
 197                  * flush the entire buffer for now as we haven't read the
 198                  * reply length (it's only 2 cache lines anyway)
 199                  */
 200                 faddr = (unsigned long)smu->cmd_buf;
 201                 flush_inval_dcache_range(faddr, faddr + 256);
 202
 203                 /* Now check ack */
 204                 ack = (~cmd->cmd) & 0xff;
 205                 if (ack != smu->cmd_buf->cmd) {
 206                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 207                                 ack, smu->cmd_buf->cmd);
 208                         rc = -EIO;
 209                 }
 210                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 211                 DPRINTK("SMU: reply len: %d\n", reply_len);
 212                 if (reply_len > cmd->reply_len) {
 213                         printk(KERN_WARNING "SMU: reply buffer too small,"
 214                                "got %d bytes for a %d bytes buffer\n",
 215                                reply_len, cmd->reply_len);
 216                         reply_len = cmd->reply_len;
 217                 }
 218                 cmd->reply_len = reply_len;
 219                 if (cmd->reply_buf && reply_len)
 220                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 221         }
 222
 223         /* Now complete the command. Write status last in order as we lost
 224          * ownership of the command structure as soon as it's no longer -1
 225          */
 226         done = cmd->done;
 227         misc = cmd->misc;
 228         mb();
 229         cmd->status = rc;
 230
 231         /* Re-enable NAP mode */
 232         if (smu->broken_nap)
 233                 powersave_nap = 1;
 234  bail:
 235         /* Start next command if any */
 236         smu_start_cmd();
 237         spin_unlock_irqrestore(&smu->lock, flags);
 238
 239         /* Call command completion handler if any */
 240         if (done)
 241                 done(cmd, misc);
 242
 243         /* It's an edge interrupt, nothing to do */
 244         return IRQ_HANDLED;
 245 }
 246
 247
 248 static irqreturn_t smu_msg_intr(int irq, void *arg)
 249 {
 250         /* I don't quite know what to do with this one, we seem to never
 251          * receive it, so I suspect we have to arm it someway in the SMU
 252          * to start getting events that way.
 253          */
 254
 255         printk(KERN_INFO "SMU: message interrupt !\n");
 256
 257         /* It's an edge interrupt, nothing to do */
 258         return IRQ_HANDLED;
 259 }
 260
 261
 262 /*
 263  * Queued command management.
 264  *
 265  */
 266
 267 int smu_queue_cmd(struct smu_cmd *cmd)
 268 {
 269         unsigned long flags;
 270
 271         if (smu == NULL)
 272                 return -ENODEV;
 273         if (cmd->data_len > SMU_MAX_DATA ||
 274             cmd->reply_len > SMU_MAX_DATA)
 275                 return -EINVAL;
 276
 277         cmd->status = 1;
 278         spin_lock_irqsave(&smu->lock, flags);
 279         list_add_tail(&cmd->link, &smu->cmd_list);
 280         if (smu->cmd_cur == NULL)
 281                 smu_start_cmd();
 282         spin_unlock_irqrestore(&smu->lock, flags);
 283
 284         /* Workaround for early calls when irq isn't available */
 285         if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 286                 smu_spinwait_cmd(cmd);
 287
 288         return 0;
 289 }
 290 EXPORT_SYMBOL(smu_queue_cmd);
 291
 292
 293 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 294                      unsigned int data_len,
 295                      void (*done)(struct smu_cmd *cmd, void *misc),
 296                      void *misc, ...)
 297 {
 298         struct smu_cmd *cmd = &scmd->cmd;
 299         va_list list;
 300         int i;
 301
 302         if (data_len > sizeof(scmd->buffer))
 303                 return -EINVAL;
 304
 305         memset(scmd, 0, sizeof(*scmd));
 306         cmd->cmd = command;
 307         cmd->data_len = data_len;
 308         cmd->data_buf = scmd->buffer;
 309         cmd->reply_len = sizeof(scmd->buffer);
 310         cmd->reply_buf = scmd->buffer;
 311         cmd->done = done;
 312         cmd->misc = misc;
 313
 314         va_start(list, misc);
 315         for (i = 0; i < data_len; ++i)
 316                 scmd->buffer[i] = (u8)va_arg(list, int);
 317         va_end(list);
 318
 319         return smu_queue_cmd(cmd);
 320 }
 321 EXPORT_SYMBOL(smu_queue_simple);
 322
 323
 324 void smu_poll(void)
 325 {
 326         u8 gpio;
 327
 328         if (smu == NULL)
 329                 return;
 330
 331         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 332         if ((gpio & 7) == 7)
 333                 smu_db_intr(smu->db_irq, smu);
 334 }
 335 EXPORT_SYMBOL(smu_poll);
 336
 337
 338 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 339 {
 340         struct completion *comp = misc;
 341
 342         complete(comp);
 343 }
 344 EXPORT_SYMBOL(smu_done_complete);
 345
 346
 347 void smu_spinwait_cmd(struct smu_cmd *cmd)
 348 {
 349         while(cmd->status == 1)
 350                 smu_poll();
 351 }
 352 EXPORT_SYMBOL(smu_spinwait_cmd);
 353
 354
 355 /* RTC low level commands */
 356 static inline int bcd2hex (int n)
 357 {
 358         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 359 }
 360
 361
 362 static inline int hex2bcd (int n)
 363 {
 364         return ((n / 10) << 4) + (n % 10);
 365 }
 366
 367
 368 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 369                                         struct rtc_time *time)
 370 {
 371         cmd_buf->cmd = 0x8e;
 372         cmd_buf->length = 8;
 373         cmd_buf->data[0] = 0x80;
 374         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 375         cmd_buf->data[2] = hex2bcd(time->tm_min);
 376         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 377         cmd_buf->data[4] = time->tm_wday;
 378         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 379         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 380         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 381 }
 382
 383
 384 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 385 {
 386         struct smu_simple_cmd cmd;
 387         int rc;
 388
 389         if (smu == NULL)
 390                 return -ENODEV;
 391
 392         memset(time, 0, sizeof(struct rtc_time));
 393         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 394                               SMU_CMD_RTC_GET_DATETIME);
 395         if (rc)
 396                 return rc;
 397         smu_spinwait_simple(&cmd);
 398
 399         time->tm_sec = bcd2hex(cmd.buffer[0]);
 400         time->tm_min = bcd2hex(cmd.buffer[1]);
 401         time->tm_hour = bcd2hex(cmd.buffer[2]);
 402         time->tm_wday = bcd2hex(cmd.buffer[3]);
 403         time->tm_mday = bcd2hex(cmd.buffer[4]);
 404         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 405         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 406
 407         return 0;
 408 }
 409
 410
 411 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 412 {
 413         struct smu_simple_cmd cmd;
 414         int rc;
 415
 416         if (smu == NULL)
 417                 return -ENODEV;
 418
 419         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 420                               SMU_CMD_RTC_SET_DATETIME,
 421                               hex2bcd(time->tm_sec),
 422                               hex2bcd(time->tm_min),
 423                               hex2bcd(time->tm_hour),
 424                               time->tm_wday,
 425                               hex2bcd(time->tm_mday),
 426                               hex2bcd(time->tm_mon) + 1,
 427                               hex2bcd(time->tm_year - 100));
 428         if (rc)
 429                 return rc;
 430         smu_spinwait_simple(&cmd);
 431
 432         return 0;
 433 }
 434
 435
 436 void smu_shutdown(void)
 437 {
 438         struct smu_simple_cmd cmd;
 439
 440         if (smu == NULL)
 441                 return;
 442
 443         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 444                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 445                 return;
 446         smu_spinwait_simple(&cmd);
 447         for (;;)
 448                 ;
 449 }
 450
 451
 452 void smu_restart(void)
 453 {
 454         struct smu_simple_cmd cmd;
 455
 456         if (smu == NULL)
 457                 return;
 458
 459         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 460                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 461                 return;
 462         smu_spinwait_simple(&cmd);
 463         for (;;)
 464                 ;
 465 }
 466
 467
 468 int smu_present(void)
 469 {
 470         return smu != NULL;
 471 }
 472 EXPORT_SYMBOL(smu_present);
 473
 474
 475 int __init smu_init (void)
 476 {
 477         struct device_node *np;
 478         const u32 *data;
 479         int ret = 0;
 480
 481         np = of_find_node_by_type(NULL, "smu");
 482         if (np == NULL)
 483                 return -ENODEV;
 484
 485         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 486
 487         if (smu_cmdbuf_abs == 0) {
 488                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 489                 ret = -EINVAL;
 490                 goto fail_np;
 491         }
 492
 493         smu = alloc_bootmem(sizeof(struct smu_device));
 494
 495         spin_lock_init(&smu->lock);
 496         INIT_LIST_HEAD(&smu->cmd_list);
 497         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 498         smu->of_node = np;
 499         smu->db_irq = NO_IRQ;
 500         smu->msg_irq = NO_IRQ;
 501
 502         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 503          * 32 bits value safely
 504          */
 505         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 506         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 507
 508         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 509         if (smu->db_node == NULL) {
 510                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 511                 ret = -ENXIO;
 512                 goto fail_bootmem;
 513         }
 514         data = of_get_property(smu->db_node, "reg", NULL);
 515         if (data == NULL) {
 516                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 517                 ret = -ENXIO;
 518                 goto fail_db_node;
 519         }
 520
 521         /* Current setup has one doorbell GPIO that does both doorbell
 522          * and ack. GPIOs are at 0x50, best would be to find that out
 523          * in the device-tree though.
 524          */
 525         smu->doorbell = *data;
 526         if (smu->doorbell < 0x50)
 527                 smu->doorbell += 0x50;
 528
 529         /* Now look for the smu-interrupt GPIO */
 530         do {
 531                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 532                 if (smu->msg_node == NULL)
 533                         break;
 534                 data = of_get_property(smu->msg_node, "reg", NULL);
 535                 if (data == NULL) {
 536                         of_node_put(smu->msg_node);
 537                         smu->msg_node = NULL;
 538                         break;
 539                 }
 540                 smu->msg = *data;
 541                 if (smu->msg < 0x50)
 542                         smu->msg += 0x50;
 543         } while(0);
 544
 545         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 546          * device-tree entry giving the address. Best would probably to use
 547          * an offset for K2 base though, but let's do it that way for now.
 548          */
 549         smu->db_buf = ioremap(0x8000860c, 0x1000);
 550         if (smu->db_buf == NULL) {
 551                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 552                 ret = -ENXIO;
 553                 goto fail_msg_node;
 554         }
 555
 556         /* U3 has an issue with NAP mode when issuing SMU commands */
 557         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 558         if (smu->broken_nap)
 559                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 560
 561         sys_ctrler = SYS_CTRLER_SMU;
 562         return 0;
 563
 564 fail_msg_node:
 565         if (smu->msg_node)
 566                 of_node_put(smu->msg_node);
 567 fail_db_node:
 568         of_node_put(smu->db_node);
 569 fail_bootmem:
 570         free_bootmem((unsigned long)smu, sizeof(struct smu_device));
 571         smu = NULL;
 572 fail_np:
 573         of_node_put(np);
 574         return ret;
 575 }
 576
 577
 578 static int smu_late_init(void)
 579 {
 580         if (!smu)
 581                 return 0;
 582
 583         init_timer(&smu->i2c_timer);
 584         smu->i2c_timer.function = smu_i2c_retry;
 585         smu->i2c_timer.data = (unsigned long)smu;
 586
 587         if (smu->db_node) {
 588                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 589                 if (smu->db_irq == NO_IRQ)
 590                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 591                                smu->db_node->full_name);
 592         }
 593         if (smu->msg_node) {
 594                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 595                 if (smu->msg_irq == NO_IRQ)
 596                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
 597                                smu->msg_node->full_name);
 598         }
 599
 600         /*
 601          * Try to request the interrupts
 602          */
 603
 604         if (smu->db_irq != NO_IRQ) {
 605                 if (request_irq(smu->db_irq, smu_db_intr,
 606                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 607                         printk(KERN_WARNING "SMU: can't "
 608                                "request interrupt %d\n",
 609                                smu->db_irq);
 610                         smu->db_irq = NO_IRQ;
 611                 }
 612         }
 613
 614         if (smu->msg_irq != NO_IRQ) {
 615                 if (request_irq(smu->msg_irq, smu_msg_intr,
 616                                 IRQF_SHARED, "SMU message", smu) < 0) {
 617                         printk(KERN_WARNING "SMU: can't "
 618                                "request interrupt %d\n",
 619                                smu->msg_irq);
 620                         smu->msg_irq = NO_IRQ;
 621                 }
 622         }
 623
 624         smu_irq_inited = 1;
 625         return 0;
 626 }
 627 /* This has to be before arch_initcall as the low i2c stuff relies on the
 628  * above having been done before we reach arch_initcalls
 629  */
 630 core_initcall(smu_late_init);
 631
 632 /*
 633  * sysfs visibility
 634  */
 635
 636 static void smu_expose_childs(struct work_struct *unused)
 637 {
 638         struct device_node *np;
 639
 640         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 641                 if (of_device_is_compatible(np, "smu-sensors"))
 642                         of_platform_device_create(np, "smu-sensors",
 643                                                   &smu->of_dev->dev);
 644 }
 645
 646 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 647
 648 static int smu_platform_probe(struct platform_device* dev)
 649 {
 650         if (!smu)
 651                 return -ENODEV;
 652         smu->of_dev = dev;
 653
 654         /*
 655          * Ok, we are matched, now expose all i2c busses. We have to defer
 656          * that unfortunately or it would deadlock inside the device model
 657          */
 658         schedule_work(&smu_expose_childs_work);
 659
 660         return 0;
 661 }
 662
 663 static const struct of_device_id smu_platform_match[] =
 664 {
 665         {
 666                 .type           = "smu",
 667         },
 668         {},
 669 };
 670
 671 static struct platform_driver smu_of_platform_driver =
 672 {
 673         .driver = {
 674                 .name = "smu",
 675                 .owner = THIS_MODULE,
 676                 .of_match_table = smu_platform_match,
 677         },
 678         .probe          = smu_platform_probe,
 679 };
 680
 681 static int __init smu_init_sysfs(void)
 682 {
 683         /*
 684          * Due to sysfs bogosity, a sysdev is not a real device, so
 685          * we should in fact create both if we want sysdev semantics
 686          * for power management.
 687          * For now, we don't power manage machines with an SMU chip,
 688          * I'm a bit too far from figuring out how that works with those
 689          * new chipsets, but that will come back and bite us
 690          */
 691         platform_driver_register(&smu_of_platform_driver);
 692         return 0;
 693 }
 694
 695 device_initcall(smu_init_sysfs);
 696
 697 struct platform_device *smu_get_ofdev(void)
 698 {
 699         if (!smu)
 700                 return NULL;
 701         return smu->of_dev;
 702 }
 703
 704 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 705
 706 /*
 707  * i2c interface
 708  */
 709
 710 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 711 {
 712         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 713         void *misc = cmd->misc;
 714         unsigned long flags;
 715
 716         /* Check for read case */
 717         if (!fail && cmd->read) {
 718                 if (cmd->pdata[0] < 1)
 719                         fail = 1;
 720                 else
 721                         memcpy(cmd->info.data, &cmd->pdata[1],
 722                                cmd->info.datalen);
 723         }
 724
 725         DPRINTK("SMU: completing, success: %d\n", !fail);
 726
 727         /* Update status and mark no pending i2c command with lock
 728          * held so nobody comes in while we dequeue an eventual
 729          * pending next i2c command
 730          */
 731         spin_lock_irqsave(&smu->lock, flags);
 732         smu->cmd_i2c_cur = NULL;
 733         wmb();
 734         cmd->status = fail ? -EIO : 0;
 735
 736         /* Is there another i2c command waiting ? */
 737         if (!list_empty(&smu->cmd_i2c_list)) {
 738                 struct smu_i2c_cmd *newcmd;
 739
 740                 /* Fetch it, new current, remove from list */
 741                 newcmd = list_entry(smu->cmd_i2c_list.next,
 742                                     struct smu_i2c_cmd, link);
 743                 smu->cmd_i2c_cur = newcmd;
 744                 list_del(&cmd->link);
 745
 746                 /* Queue with low level smu */
 747                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 748                 if (smu->cmd_cur == NULL)
 749                         smu_start_cmd();
 750         }
 751         spin_unlock_irqrestore(&smu->lock, flags);
 752
 753         /* Call command completion handler if any */
 754         if (done)
 755                 done(cmd, misc);
 756
 757 }
 758
 759
 760 static void smu_i2c_retry(unsigned long data)
 761 {
 762         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 763
 764         DPRINTK("SMU: i2c failure, requeuing...\n");
 765
 766         /* requeue command simply by resetting reply_len */
 767         cmd->pdata[0] = 0xff;
 768         cmd->scmd.reply_len = sizeof(cmd->pdata);
 769         smu_queue_cmd(&cmd->scmd);
 770 }
 771
 772
 773 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 774 {
 775         struct smu_i2c_cmd      *cmd = misc;
 776         int                     fail = 0;
 777
 778         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 779                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 780
 781         /* Check for possible status */
 782         if (scmd->status < 0)
 783                 fail = 1;
 784         else if (cmd->read) {
 785                 if (cmd->stage == 0)
 786                         fail = cmd->pdata[0] != 0;
 787                 else
 788                         fail = cmd->pdata[0] >= 0x80;
 789         } else {
 790                 fail = cmd->pdata[0] != 0;
 791         }
 792
 793         /* Handle failures by requeuing command, after 5ms interval
 794          */
 795         if (fail && --cmd->retries > 0) {
 796                 DPRINTK("SMU: i2c failure, starting timer...\n");
 797                 BUG_ON(cmd != smu->cmd_i2c_cur);
 798                 if (!smu_irq_inited) {
 799                         mdelay(5);
 800                         smu_i2c_retry(0);
 801                         return;
 802                 }
 803                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 804                 return;
 805         }
 806
 807         /* If failure or stage 1, command is complete */
 808         if (fail || cmd->stage != 0) {
 809                 smu_i2c_complete_command(cmd, fail);
 810                 return;
 811         }
 812
 813         DPRINTK("SMU: going to stage 1\n");
 814
 815         /* Ok, initial command complete, now poll status */
 816         scmd->reply_buf = cmd->pdata;
 817         scmd->reply_len = sizeof(cmd->pdata);
 818         scmd->data_buf = cmd->pdata;
 819         scmd->data_len = 1;
 820         cmd->pdata[0] = 0;
 821         cmd->stage = 1;
 822         cmd->retries = 20;
 823         smu_queue_cmd(scmd);
 824 }
 825
 826
 827 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 828 {
 829         unsigned long flags;
 830
 831         if (smu == NULL)
 832                 return -ENODEV;
 833
 834         /* Fill most fields of scmd */
 835         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 836         cmd->scmd.done = smu_i2c_low_completion;
 837         cmd->scmd.misc = cmd;
 838         cmd->scmd.reply_buf = cmd->pdata;
 839         cmd->scmd.reply_len = sizeof(cmd->pdata);
 840         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 841         cmd->scmd.status = 1;
 842         cmd->stage = 0;
 843         cmd->pdata[0] = 0xff;
 844         cmd->retries = 20;
 845         cmd->status = 1;
 846
 847         /* Check transfer type, sanitize some "info" fields
 848          * based on transfer type and do more checking
 849          */
 850         cmd->info.caddr = cmd->info.devaddr;
 851         cmd->read = cmd->info.devaddr & 0x01;
 852         switch(cmd->info.type) {
 853         case SMU_I2C_TRANSFER_SIMPLE:
 854                 memset(&cmd->info.sublen, 0, 4);
 855                 break;
 856         case SMU_I2C_TRANSFER_COMBINED:
 857                 cmd->info.devaddr &= 0xfe;
 858         case SMU_I2C_TRANSFER_STDSUB:
 859                 if (cmd->info.sublen > 3)
 860                         return -EINVAL;
 861                 break;
 862         default:
 863                 return -EINVAL;
 864         }
 865
 866         /* Finish setting up command based on transfer direction
 867          */
 868         if (cmd->read) {
 869                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 870                         return -EINVAL;
 871                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 872                 cmd->scmd.data_len = 9;
 873         } else {
 874                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 875                         return -EINVAL;
 876                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 877         }
 878
 879         DPRINTK("SMU: i2c enqueuing command\n");
 880         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 881                 cmd->read ? "read" : "write", cmd->info.datalen,
 882                 cmd->info.bus, cmd->info.caddr,
 883                 cmd->info.subaddr[0], cmd->info.type);
 884
 885
 886         /* Enqueue command in i2c list, and if empty, enqueue also in
 887          * main command list
 888          */
 889         spin_lock_irqsave(&smu->lock, flags);
 890         if (smu->cmd_i2c_cur == NULL) {
 891                 smu->cmd_i2c_cur = cmd;
 892                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 893                 if (smu->cmd_cur == NULL)
 894                         smu_start_cmd();
 895         } else
 896                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 897         spin_unlock_irqrestore(&smu->lock, flags);
 898
 899         return 0;
 900 }
 901
 902 /*
 903  * Handling of "partitions"
 904  */
 905
 906 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 907 {
 908         DECLARE_COMPLETION_ONSTACK(comp);
 909         unsigned int chunk;
 910         struct smu_cmd cmd;
 911         int rc;
 912         u8 params[8];
 913
 914         /* We currently use a chunk size of 0xe. We could check the
 915          * SMU firmware version and use bigger sizes though
 916          */
 917         chunk = 0xe;
 918
 919         while (len) {
 920                 unsigned int clen = min(len, chunk);
 921
 922                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 923                 cmd.data_len = 7;
 924                 cmd.data_buf = params;
 925                 cmd.reply_len = chunk;
 926                 cmd.reply_buf = dest;
 927                 cmd.done = smu_done_complete;
 928                 cmd.misc = &comp;
 929                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 930                 params[1] = 0x4;
 931                 *((u32 *)&params[2]) = addr;
 932                 params[6] = clen;
 933
 934                 rc = smu_queue_cmd(&cmd);
 935                 if (rc)
 936                         return rc;
 937                 wait_for_completion(&comp);
 938                 if (cmd.status != 0)
 939                         return rc;
 940                 if (cmd.reply_len != clen) {
 941                         printk(KERN_DEBUG "SMU: short read in "
 942                                "smu_read_datablock, got: %d, want: %d\n",
 943                                cmd.reply_len, clen);
 944                         return -EIO;
 945                 }
 946                 len -= clen;
 947                 addr += clen;
 948                 dest += clen;
 949         }
 950         return 0;
 951 }
 952
 953 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 954 {
 955         DECLARE_COMPLETION_ONSTACK(comp);
 956         struct smu_simple_cmd cmd;
 957         unsigned int addr, len, tlen;
 958         struct smu_sdbp_header *hdr;
 959         struct property *prop;
 960
 961         /* First query the partition info */
 962         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 963         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 964                          smu_done_complete, &comp,
 965                          SMU_CMD_PARTITION_LATEST, id);
 966         wait_for_completion(&comp);
 967         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 968                 cmd.cmd.status, cmd.cmd.reply_len);
 969
 970         /* Partition doesn't exist (or other error) */
 971         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 972                 return NULL;
 973
 974         /* Fetch address and length from reply */
 975         addr = *((u16 *)cmd.buffer);
 976         len = cmd.buffer[3] << 2;
 977         /* Calucluate total length to allocate, including the 17 bytes
 978          * for "sdb-partition-XX" that we append at the end of the buffer
 979          */
 980         tlen = sizeof(struct property) + len + 18;
 981
 982         prop = kzalloc(tlen, GFP_KERNEL);
 983         if (prop == NULL)
 984                 return NULL;
 985         hdr = (struct smu_sdbp_header *)(prop + 1);
 986         prop->name = ((char *)prop) + tlen - 18;
 987         sprintf(prop->name, "sdb-partition-%02x", id);
 988         prop->length = len;
 989         prop->value = hdr;
 990         prop->next = NULL;
 991
 992         /* Read the datablock */
 993         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 994                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 995                        "partition %02x !\n", id);
 996                 goto failure;
 997         }
 998
 999         /* Got it, check a few things and create the property */
1000         if (hdr->id != id) {
1001                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
1002                        "%02x !\n", id, hdr->id);
1003                 goto failure;
1004         }
1005         if (prom_add_property(smu->of_node, prop)) {
1006                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1007                        "property !\n", id);
1008                 goto failure;
1009         }
1010
1011         return hdr;
1012  failure:
1013         kfree(prop);
1014         return NULL;
1015 }
1016
1017 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1018  * when interruptible is 1
1019  */
1020 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1021                 unsigned int *size, int interruptible)
1022 {
1023         char pname[32];
1024         const struct smu_sdbp_header *part;
1025
1026         if (!smu)
1027                 return NULL;
1028
1029         sprintf(pname, "sdb-partition-%02x", id);
1030
1031         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1032
1033         if (interruptible) {
1034                 int rc;
1035                 rc = mutex_lock_interruptible(&smu_part_access);
1036                 if (rc)
1037                         return ERR_PTR(rc);
1038         } else
1039                 mutex_lock(&smu_part_access);
1040
1041         part = of_get_property(smu->of_node, pname, size);
1042         if (part == NULL) {
1043                 DPRINTK("trying to extract from SMU ...\n");
1044                 part = smu_create_sdb_partition(id);
1045                 if (part != NULL && size)
1046                         *size = part->len << 2;
1047         }
1048         mutex_unlock(&smu_part_access);
1049         return part;
1050 }
1051
1052 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1053 {
1054         return __smu_get_sdb_partition(id, size, 0);
1055 }
1056 EXPORT_SYMBOL(smu_get_sdb_partition);
1057
1058
1059 /*
1060  * Userland driver interface
1061  */
1062
1063
1064 static LIST_HEAD(smu_clist);
1065 static DEFINE_SPINLOCK(smu_clist_lock);
1066
1067 enum smu_file_mode {
1068         smu_file_commands,
1069         smu_file_events,
1070         smu_file_closing
1071 };
1072
1073 struct smu_private
1074 {
1075         struct list_head        list;
1076         enum smu_file_mode      mode;
1077         int                     busy;
1078         struct smu_cmd          cmd;
1079         spinlock_t              lock;
1080         wait_queue_head_t       wait;
1081         u8                      buffer[SMU_MAX_DATA];
1082 };
1083
1084
1085 static int smu_open(struct inode *inode, struct file *file)
1086 {
1087         struct smu_private *pp;
1088         unsigned long flags;
1089
1090         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1091         if (pp == 0)
1092                 return -ENOMEM;
1093         spin_lock_init(&pp->lock);
1094         pp->mode = smu_file_commands;
1095         init_waitqueue_head(&pp->wait);
1096
1097         mutex_lock(&smu_mutex);
1098         spin_lock_irqsave(&smu_clist_lock, flags);
1099         list_add(&pp->list, &smu_clist);
1100         spin_unlock_irqrestore(&smu_clist_lock, flags);
1101         file->private_data = pp;
1102         mutex_unlock(&smu_mutex);
1103
1104         return 0;
1105 }
1106
1107
1108 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1109 {
1110         struct smu_private *pp = misc;
1111
1112         wake_up_all(&pp->wait);
1113 }
1114
1115
1116 static ssize_t smu_write(struct file *file, const char __user *buf,
1117                          size_t count, loff_t *ppos)
1118 {
1119         struct smu_private *pp = file->private_data;
1120         unsigned long flags;
1121         struct smu_user_cmd_hdr hdr;
1122         int rc = 0;
1123
1124         if (pp->busy)
1125                 return -EBUSY;
1126         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1127                 return -EFAULT;
1128         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1129                 pp->mode = smu_file_events;
1130                 return 0;
1131         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1132                 const struct smu_sdbp_header *part;
1133                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1134                 if (part == NULL)
1135                         return -EINVAL;
1136                 else if (IS_ERR(part))
1137                         return PTR_ERR(part);
1138                 return 0;
1139         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1140                 return -EINVAL;
1141         else if (pp->mode != smu_file_commands)
1142                 return -EBADFD;
1143         else if (hdr.data_len > SMU_MAX_DATA)
1144                 return -EINVAL;
1145
1146         spin_lock_irqsave(&pp->lock, flags);
1147         if (pp->busy) {
1148                 spin_unlock_irqrestore(&pp->lock, flags);
1149                 return -EBUSY;
1150         }
1151         pp->busy = 1;
1152         pp->cmd.status = 1;
1153         spin_unlock_irqrestore(&pp->lock, flags);
1154
1155         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1156                 pp->busy = 0;
1157                 return -EFAULT;
1158         }
1159
1160         pp->cmd.cmd = hdr.cmd;
1161         pp->cmd.data_len = hdr.data_len;
1162         pp->cmd.reply_len = SMU_MAX_DATA;
1163         pp->cmd.data_buf = pp->buffer;
1164         pp->cmd.reply_buf = pp->buffer;
1165         pp->cmd.done = smu_user_cmd_done;
1166         pp->cmd.misc = pp;
1167         rc = smu_queue_cmd(&pp->cmd);
1168         if (rc < 0)
1169                 return rc;
1170         return count;
1171 }
1172
1173
1174 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1175                                 char __user *buf, size_t count)
1176 {
1177         DECLARE_WAITQUEUE(wait, current);
1178         struct smu_user_reply_hdr hdr;
1179         unsigned long flags;
1180         int size, rc = 0;
1181
1182         if (!pp->busy)
1183                 return 0;
1184         if (count < sizeof(struct smu_user_reply_hdr))
1185                 return -EOVERFLOW;
1186         spin_lock_irqsave(&pp->lock, flags);
1187         if (pp->cmd.status == 1) {
1188                 if (file->f_flags & O_NONBLOCK) {
1189                         spin_unlock_irqrestore(&pp->lock, flags);
1190                         return -EAGAIN;
1191                 }
1192                 add_wait_queue(&pp->wait, &wait);
1193                 for (;;) {
1194                         set_current_state(TASK_INTERRUPTIBLE);
1195                         rc = 0;
1196                         if (pp->cmd.status != 1)
1197                                 break;
1198                         rc = -ERESTARTSYS;
1199                         if (signal_pending(current))
1200                                 break;
1201                         spin_unlock_irqrestore(&pp->lock, flags);
1202                         schedule();
1203                         spin_lock_irqsave(&pp->lock, flags);
1204                 }
1205                 set_current_state(TASK_RUNNING);
1206                 remove_wait_queue(&pp->wait, &wait);
1207         }
1208         spin_unlock_irqrestore(&pp->lock, flags);
1209         if (rc)
1210                 return rc;
1211         if (pp->cmd.status != 0)
1212                 pp->cmd.reply_len = 0;
1213         size = sizeof(hdr) + pp->cmd.reply_len;
1214         if (count < size)
1215                 size = count;
1216         rc = size;
1217         hdr.status = pp->cmd.status;
1218         hdr.reply_len = pp->cmd.reply_len;
1219         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1220                 return -EFAULT;
1221         size -= sizeof(hdr);
1222         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1223                 return -EFAULT;
1224         pp->busy = 0;
1225
1226         return rc;
1227 }
1228
1229
1230 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1231                                char __user *buf, size_t count)
1232 {
1233         /* Not implemented */
1234         msleep_interruptible(1000);
1235         return 0;
1236 }
1237
1238
1239 static ssize_t smu_read(struct file *file, char __user *buf,
1240                         size_t count, loff_t *ppos)
1241 {
1242         struct smu_private *pp = file->private_data;
1243
1244         if (pp->mode == smu_file_commands)
1245                 return smu_read_command(file, pp, buf, count);
1246         if (pp->mode == smu_file_events)
1247                 return smu_read_events(file, pp, buf, count);
1248
1249         return -EBADFD;
1250 }
1251
1252 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1253 {
1254         struct smu_private *pp = file->private_data;
1255         unsigned int mask = 0;
1256         unsigned long flags;
1257
1258         if (pp == 0)
1259                 return 0;
1260
1261         if (pp->mode == smu_file_commands) {
1262                 poll_wait(file, &pp->wait, wait);
1263
1264                 spin_lock_irqsave(&pp->lock, flags);
1265                 if (pp->busy && pp->cmd.status != 1)
1266                         mask |= POLLIN;
1267                 spin_unlock_irqrestore(&pp->lock, flags);
1268         } if (pp->mode == smu_file_events) {
1269                 /* Not yet implemented */
1270         }
1271         return mask;
1272 }
1273
1274 static int smu_release(struct inode *inode, struct file *file)
1275 {
1276         struct smu_private *pp = file->private_data;
1277         unsigned long flags;
1278         unsigned int busy;
1279
1280         if (pp == 0)
1281                 return 0;
1282
1283         file->private_data = NULL;
1284
1285         /* Mark file as closing to avoid races with new request */
1286         spin_lock_irqsave(&pp->lock, flags);
1287         pp->mode = smu_file_closing;
1288         busy = pp->busy;
1289
1290         /* Wait for any pending request to complete */
1291         if (busy && pp->cmd.status == 1) {
1292                 DECLARE_WAITQUEUE(wait, current);
1293
1294                 add_wait_queue(&pp->wait, &wait);
1295                 for (;;) {
1296                         set_current_state(TASK_UNINTERRUPTIBLE);
1297                         if (pp->cmd.status != 1)
1298                                 break;
1299                         spin_unlock_irqrestore(&pp->lock, flags);
1300                         schedule();
1301                         spin_lock_irqsave(&pp->lock, flags);
1302                 }
1303                 set_current_state(TASK_RUNNING);
1304                 remove_wait_queue(&pp->wait, &wait);
1305         }
1306         spin_unlock_irqrestore(&pp->lock, flags);
1307
1308         spin_lock_irqsave(&smu_clist_lock, flags);
1309         list_del(&pp->list);
1310         spin_unlock_irqrestore(&smu_clist_lock, flags);
1311         kfree(pp);
1312
1313         return 0;
1314 }
1315
1316
1317 static const struct file_operations smu_device_fops = {
1318         .llseek         = no_llseek,
1319         .read           = smu_read,
1320         .write          = smu_write,
1321         .poll           = smu_fpoll,
1322         .open           = smu_open,
1323         .release        = smu_release,
1324 };
1325
1326 static struct miscdevice pmu_device = {
1327         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1328 };
1329
1330 static int smu_device_init(void)
1331 {
1332         if (!smu)
1333                 return -ENODEV;
1334         if (misc_register(&pmu_device) < 0)
1335                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1336         return 0;
1337 }
1338 device_initcall(smu_device_init);