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/smp_lock.h>
  23 #include <linux/types.h>
  24 #include <linux/kernel.h>
  25 #include <linux/device.h>
  26 #include <linux/dmapool.h>
  27 #include <linux/bootmem.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/highmem.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/rtc.h>
  33 #include <linux/completion.h>
  34 #include <linux/miscdevice.h>
  35 #include <linux/delay.h>
  36 #include <linux/sysdev.h>
  37 #include <linux/poll.h>
  38 #include <linux/mutex.h>
  39 #include <linux/of_device.h>
  40 #include <linux/of_platform.h>
  41 #include <linux/slab.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 <asm/abs_addr.h>
  51 #include <asm/uaccess.h>
  52
  53 #define VERSION "0.7"
  54 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  55
  56 #undef DEBUG_SMU
  57
  58 #ifdef DEBUG_SMU
  59 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  60 #else
  61 #define DPRINTK(fmt, args...) do { } while (0)
  62 #endif
  63
  64 /*
  65  * This is the command buffer passed to the SMU hardware
  66  */
  67 #define SMU_MAX_DATA    254
  68
  69 struct smu_cmd_buf {
  70         u8 cmd;
  71         u8 length;
  72         u8 data[SMU_MAX_DATA];
  73 };
  74
  75 struct smu_device {
  76         spinlock_t              lock;
  77         struct device_node      *of_node;
  78         struct of_device        *of_dev;
  79         int                     doorbell;       /* doorbell gpio */
  80         u32 __iomem             *db_buf;        /* doorbell buffer */
  81         struct device_node      *db_node;
  82         unsigned int            db_irq;
  83         int                     msg;
  84         struct device_node      *msg_node;
  85         unsigned int            msg_irq;
  86         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  87         u32                     cmd_buf_abs;    /* command buffer absolute */
  88         struct list_head        cmd_list;
  89         struct smu_cmd          *cmd_cur;       /* pending command */
  90         int                     broken_nap;
  91         struct list_head        cmd_i2c_list;
  92         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  93         struct timer_list       i2c_timer;
  94 };
  95
  96 /*
  97  * I don't think there will ever be more than one SMU, so
  98  * for now, just hard code that
  99  */
 100 static 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 of_device* dev,
 649                               const struct of_device_id *match)
 650 {
 651         if (!smu)
 652                 return -ENODEV;
 653         smu->of_dev = dev;
 654
 655         /*
 656          * Ok, we are matched, now expose all i2c busses. We have to defer
 657          * that unfortunately or it would deadlock inside the device model
 658          */
 659         schedule_work(&smu_expose_childs_work);
 660
 661         return 0;
 662 }
 663
 664 static const struct of_device_id smu_platform_match[] =
 665 {
 666         {
 667                 .type           = "smu",
 668         },
 669         {},
 670 };
 671
 672 static struct of_platform_driver smu_of_platform_driver =
 673 {
 674         .name           = "smu",
 675         .match_table    = smu_platform_match,
 676         .probe          = smu_platform_probe,
 677 };
 678
 679 static int __init smu_init_sysfs(void)
 680 {
 681         /*
 682          * Due to sysfs bogosity, a sysdev is not a real device, so
 683          * we should in fact create both if we want sysdev semantics
 684          * for power management.
 685          * For now, we don't power manage machines with an SMU chip,
 686          * I'm a bit too far from figuring out how that works with those
 687          * new chipsets, but that will come back and bite us
 688          */
 689         of_register_platform_driver(&smu_of_platform_driver);
 690         return 0;
 691 }
 692
 693 device_initcall(smu_init_sysfs);
 694
 695 struct of_device *smu_get_ofdev(void)
 696 {
 697         if (!smu)
 698                 return NULL;
 699         return smu->of_dev;
 700 }
 701
 702 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 703
 704 /*
 705  * i2c interface
 706  */
 707
 708 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 709 {
 710         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 711         void *misc = cmd->misc;
 712         unsigned long flags;
 713
 714         /* Check for read case */
 715         if (!fail && cmd->read) {
 716                 if (cmd->pdata[0] < 1)
 717                         fail = 1;
 718                 else
 719                         memcpy(cmd->info.data, &cmd->pdata[1],
 720                                cmd->info.datalen);
 721         }
 722
 723         DPRINTK("SMU: completing, success: %d\n", !fail);
 724
 725         /* Update status and mark no pending i2c command with lock
 726          * held so nobody comes in while we dequeue an eventual
 727          * pending next i2c command
 728          */
 729         spin_lock_irqsave(&smu->lock, flags);
 730         smu->cmd_i2c_cur = NULL;
 731         wmb();
 732         cmd->status = fail ? -EIO : 0;
 733
 734         /* Is there another i2c command waiting ? */
 735         if (!list_empty(&smu->cmd_i2c_list)) {
 736                 struct smu_i2c_cmd *newcmd;
 737
 738                 /* Fetch it, new current, remove from list */
 739                 newcmd = list_entry(smu->cmd_i2c_list.next,
 740                                     struct smu_i2c_cmd, link);
 741                 smu->cmd_i2c_cur = newcmd;
 742                 list_del(&cmd->link);
 743
 744                 /* Queue with low level smu */
 745                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 746                 if (smu->cmd_cur == NULL)
 747                         smu_start_cmd();
 748         }
 749         spin_unlock_irqrestore(&smu->lock, flags);
 750
 751         /* Call command completion handler if any */
 752         if (done)
 753                 done(cmd, misc);
 754
 755 }
 756
 757
 758 static void smu_i2c_retry(unsigned long data)
 759 {
 760         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 761
 762         DPRINTK("SMU: i2c failure, requeuing...\n");
 763
 764         /* requeue command simply by resetting reply_len */
 765         cmd->pdata[0] = 0xff;
 766         cmd->scmd.reply_len = sizeof(cmd->pdata);
 767         smu_queue_cmd(&cmd->scmd);
 768 }
 769
 770
 771 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 772 {
 773         struct smu_i2c_cmd      *cmd = misc;
 774         int                     fail = 0;
 775
 776         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 777                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 778
 779         /* Check for possible status */
 780         if (scmd->status < 0)
 781                 fail = 1;
 782         else if (cmd->read) {
 783                 if (cmd->stage == 0)
 784                         fail = cmd->pdata[0] != 0;
 785                 else
 786                         fail = cmd->pdata[0] >= 0x80;
 787         } else {
 788                 fail = cmd->pdata[0] != 0;
 789         }
 790
 791         /* Handle failures by requeuing command, after 5ms interval
 792          */
 793         if (fail && --cmd->retries > 0) {
 794                 DPRINTK("SMU: i2c failure, starting timer...\n");
 795                 BUG_ON(cmd != smu->cmd_i2c_cur);
 796                 if (!smu_irq_inited) {
 797                         mdelay(5);
 798                         smu_i2c_retry(0);
 799                         return;
 800                 }
 801                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 802                 return;
 803         }
 804
 805         /* If failure or stage 1, command is complete */
 806         if (fail || cmd->stage != 0) {
 807                 smu_i2c_complete_command(cmd, fail);
 808                 return;
 809         }
 810
 811         DPRINTK("SMU: going to stage 1\n");
 812
 813         /* Ok, initial command complete, now poll status */
 814         scmd->reply_buf = cmd->pdata;
 815         scmd->reply_len = sizeof(cmd->pdata);
 816         scmd->data_buf = cmd->pdata;
 817         scmd->data_len = 1;
 818         cmd->pdata[0] = 0;
 819         cmd->stage = 1;
 820         cmd->retries = 20;
 821         smu_queue_cmd(scmd);
 822 }
 823
 824
 825 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 826 {
 827         unsigned long flags;
 828
 829         if (smu == NULL)
 830                 return -ENODEV;
 831
 832         /* Fill most fields of scmd */
 833         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 834         cmd->scmd.done = smu_i2c_low_completion;
 835         cmd->scmd.misc = cmd;
 836         cmd->scmd.reply_buf = cmd->pdata;
 837         cmd->scmd.reply_len = sizeof(cmd->pdata);
 838         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 839         cmd->scmd.status = 1;
 840         cmd->stage = 0;
 841         cmd->pdata[0] = 0xff;
 842         cmd->retries = 20;
 843         cmd->status = 1;
 844
 845         /* Check transfer type, sanitize some "info" fields
 846          * based on transfer type and do more checking
 847          */
 848         cmd->info.caddr = cmd->info.devaddr;
 849         cmd->read = cmd->info.devaddr & 0x01;
 850         switch(cmd->info.type) {
 851         case SMU_I2C_TRANSFER_SIMPLE:
 852                 memset(&cmd->info.sublen, 0, 4);
 853                 break;
 854         case SMU_I2C_TRANSFER_COMBINED:
 855                 cmd->info.devaddr &= 0xfe;
 856         case SMU_I2C_TRANSFER_STDSUB:
 857                 if (cmd->info.sublen > 3)
 858                         return -EINVAL;
 859                 break;
 860         default:
 861                 return -EINVAL;
 862         }
 863
 864         /* Finish setting up command based on transfer direction
 865          */
 866         if (cmd->read) {
 867                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 868                         return -EINVAL;
 869                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 870                 cmd->scmd.data_len = 9;
 871         } else {
 872                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 873                         return -EINVAL;
 874                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 875         }
 876
 877         DPRINTK("SMU: i2c enqueuing command\n");
 878         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 879                 cmd->read ? "read" : "write", cmd->info.datalen,
 880                 cmd->info.bus, cmd->info.caddr,
 881                 cmd->info.subaddr[0], cmd->info.type);
 882
 883
 884         /* Enqueue command in i2c list, and if empty, enqueue also in
 885          * main command list
 886          */
 887         spin_lock_irqsave(&smu->lock, flags);
 888         if (smu->cmd_i2c_cur == NULL) {
 889                 smu->cmd_i2c_cur = cmd;
 890                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 891                 if (smu->cmd_cur == NULL)
 892                         smu_start_cmd();
 893         } else
 894                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 895         spin_unlock_irqrestore(&smu->lock, flags);
 896
 897         return 0;
 898 }
 899
 900 /*
 901  * Handling of "partitions"
 902  */
 903
 904 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 905 {
 906         DECLARE_COMPLETION_ONSTACK(comp);
 907         unsigned int chunk;
 908         struct smu_cmd cmd;
 909         int rc;
 910         u8 params[8];
 911
 912         /* We currently use a chunk size of 0xe. We could check the
 913          * SMU firmware version and use bigger sizes though
 914          */
 915         chunk = 0xe;
 916
 917         while (len) {
 918                 unsigned int clen = min(len, chunk);
 919
 920                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 921                 cmd.data_len = 7;
 922                 cmd.data_buf = params;
 923                 cmd.reply_len = chunk;
 924                 cmd.reply_buf = dest;
 925                 cmd.done = smu_done_complete;
 926                 cmd.misc = &comp;
 927                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 928                 params[1] = 0x4;
 929                 *((u32 *)&params[2]) = addr;
 930                 params[6] = clen;
 931
 932                 rc = smu_queue_cmd(&cmd);
 933                 if (rc)
 934                         return rc;
 935                 wait_for_completion(&comp);
 936                 if (cmd.status != 0)
 937                         return rc;
 938                 if (cmd.reply_len != clen) {
 939                         printk(KERN_DEBUG "SMU: short read in "
 940                                "smu_read_datablock, got: %d, want: %d\n",
 941                                cmd.reply_len, clen);
 942                         return -EIO;
 943                 }
 944                 len -= clen;
 945                 addr += clen;
 946                 dest += clen;
 947         }
 948         return 0;
 949 }
 950
 951 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 952 {
 953         DECLARE_COMPLETION_ONSTACK(comp);
 954         struct smu_simple_cmd cmd;
 955         unsigned int addr, len, tlen;
 956         struct smu_sdbp_header *hdr;
 957         struct property *prop;
 958
 959         /* First query the partition info */
 960         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 961         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 962                          smu_done_complete, &comp,
 963                          SMU_CMD_PARTITION_LATEST, id);
 964         wait_for_completion(&comp);
 965         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 966                 cmd.cmd.status, cmd.cmd.reply_len);
 967
 968         /* Partition doesn't exist (or other error) */
 969         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 970                 return NULL;
 971
 972         /* Fetch address and length from reply */
 973         addr = *((u16 *)cmd.buffer);
 974         len = cmd.buffer[3] << 2;
 975         /* Calucluate total length to allocate, including the 17 bytes
 976          * for "sdb-partition-XX" that we append at the end of the buffer
 977          */
 978         tlen = sizeof(struct property) + len + 18;
 979
 980         prop = kzalloc(tlen, GFP_KERNEL);
 981         if (prop == NULL)
 982                 return NULL;
 983         hdr = (struct smu_sdbp_header *)(prop + 1);
 984         prop->name = ((char *)prop) + tlen - 18;
 985         sprintf(prop->name, "sdb-partition-%02x", id);
 986         prop->length = len;
 987         prop->value = hdr;
 988         prop->next = NULL;
 989
 990         /* Read the datablock */
 991         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 992                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 993                        "partition %02x !\n", id);
 994                 goto failure;
 995         }
 996
 997         /* Got it, check a few things and create the property */
 998         if (hdr->id != id) {
 999                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
1000                        "%02x !\n", id, hdr->id);
1001                 goto failure;
1002         }
1003         if (prom_add_property(smu->of_node, prop)) {
1004                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1005                        "property !\n", id);
1006                 goto failure;
1007         }
1008
1009         return hdr;
1010  failure:
1011         kfree(prop);
1012         return NULL;
1013 }
1014
1015 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1016  * when interruptible is 1
1017  */
1018 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1019                 unsigned int *size, int interruptible)
1020 {
1021         char pname[32];
1022         const struct smu_sdbp_header *part;
1023
1024         if (!smu)
1025                 return NULL;
1026
1027         sprintf(pname, "sdb-partition-%02x", id);
1028
1029         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1030
1031         if (interruptible) {
1032                 int rc;
1033                 rc = mutex_lock_interruptible(&smu_part_access);
1034                 if (rc)
1035                         return ERR_PTR(rc);
1036         } else
1037                 mutex_lock(&smu_part_access);
1038
1039         part = of_get_property(smu->of_node, pname, size);
1040         if (part == NULL) {
1041                 DPRINTK("trying to extract from SMU ...\n");
1042                 part = smu_create_sdb_partition(id);
1043                 if (part != NULL && size)
1044                         *size = part->len << 2;
1045         }
1046         mutex_unlock(&smu_part_access);
1047         return part;
1048 }
1049
1050 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1051 {
1052         return __smu_get_sdb_partition(id, size, 0);
1053 }
1054 EXPORT_SYMBOL(smu_get_sdb_partition);
1055
1056
1057 /*
1058  * Userland driver interface
1059  */
1060
1061
1062 static LIST_HEAD(smu_clist);
1063 static DEFINE_SPINLOCK(smu_clist_lock);
1064
1065 enum smu_file_mode {
1066         smu_file_commands,
1067         smu_file_events,
1068         smu_file_closing
1069 };
1070
1071 struct smu_private
1072 {
1073         struct list_head        list;
1074         enum smu_file_mode      mode;
1075         int                     busy;
1076         struct smu_cmd          cmd;
1077         spinlock_t              lock;
1078         wait_queue_head_t       wait;
1079         u8                      buffer[SMU_MAX_DATA];
1080 };
1081
1082
1083 static int smu_open(struct inode *inode, struct file *file)
1084 {
1085         struct smu_private *pp;
1086         unsigned long flags;
1087
1088         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1089         if (pp == 0)
1090                 return -ENOMEM;
1091         spin_lock_init(&pp->lock);
1092         pp->mode = smu_file_commands;
1093         init_waitqueue_head(&pp->wait);
1094
1095         lock_kernel();
1096         spin_lock_irqsave(&smu_clist_lock, flags);
1097         list_add(&pp->list, &smu_clist);
1098         spin_unlock_irqrestore(&smu_clist_lock, flags);
1099         file->private_data = pp;
1100         unlock_kernel();
1101
1102         return 0;
1103 }
1104
1105
1106 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1107 {
1108         struct smu_private *pp = misc;
1109
1110         wake_up_all(&pp->wait);
1111 }
1112
1113
1114 static ssize_t smu_write(struct file *file, const char __user *buf,
1115                          size_t count, loff_t *ppos)
1116 {
1117         struct smu_private *pp = file->private_data;
1118         unsigned long flags;
1119         struct smu_user_cmd_hdr hdr;
1120         int rc = 0;
1121
1122         if (pp->busy)
1123                 return -EBUSY;
1124         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1125                 return -EFAULT;
1126         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1127                 pp->mode = smu_file_events;
1128                 return 0;
1129         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1130                 const struct smu_sdbp_header *part;
1131                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1132                 if (part == NULL)
1133                         return -EINVAL;
1134                 else if (IS_ERR(part))
1135                         return PTR_ERR(part);
1136                 return 0;
1137         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1138                 return -EINVAL;
1139         else if (pp->mode != smu_file_commands)
1140                 return -EBADFD;
1141         else if (hdr.data_len > SMU_MAX_DATA)
1142                 return -EINVAL;
1143
1144         spin_lock_irqsave(&pp->lock, flags);
1145         if (pp->busy) {
1146                 spin_unlock_irqrestore(&pp->lock, flags);
1147                 return -EBUSY;
1148         }
1149         pp->busy = 1;
1150         pp->cmd.status = 1;
1151         spin_unlock_irqrestore(&pp->lock, flags);
1152
1153         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1154                 pp->busy = 0;
1155                 return -EFAULT;
1156         }
1157
1158         pp->cmd.cmd = hdr.cmd;
1159         pp->cmd.data_len = hdr.data_len;
1160         pp->cmd.reply_len = SMU_MAX_DATA;
1161         pp->cmd.data_buf = pp->buffer;
1162         pp->cmd.reply_buf = pp->buffer;
1163         pp->cmd.done = smu_user_cmd_done;
1164         pp->cmd.misc = pp;
1165         rc = smu_queue_cmd(&pp->cmd);
1166         if (rc < 0)
1167                 return rc;
1168         return count;
1169 }
1170
1171
1172 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1173                                 char __user *buf, size_t count)
1174 {
1175         DECLARE_WAITQUEUE(wait, current);
1176         struct smu_user_reply_hdr hdr;
1177         unsigned long flags;
1178         int size, rc = 0;
1179
1180         if (!pp->busy)
1181                 return 0;
1182         if (count < sizeof(struct smu_user_reply_hdr))
1183                 return -EOVERFLOW;
1184         spin_lock_irqsave(&pp->lock, flags);
1185         if (pp->cmd.status == 1) {
1186                 if (file->f_flags & O_NONBLOCK)
1187                         return -EAGAIN;
1188                 add_wait_queue(&pp->wait, &wait);
1189                 for (;;) {
1190                         set_current_state(TASK_INTERRUPTIBLE);
1191                         rc = 0;
1192                         if (pp->cmd.status != 1)
1193                                 break;
1194                         rc = -ERESTARTSYS;
1195                         if (signal_pending(current))
1196                                 break;
1197                         spin_unlock_irqrestore(&pp->lock, flags);
1198                         schedule();
1199                         spin_lock_irqsave(&pp->lock, flags);
1200                 }
1201                 set_current_state(TASK_RUNNING);
1202                 remove_wait_queue(&pp->wait, &wait);
1203         }
1204         spin_unlock_irqrestore(&pp->lock, flags);
1205         if (rc)
1206                 return rc;
1207         if (pp->cmd.status != 0)
1208                 pp->cmd.reply_len = 0;
1209         size = sizeof(hdr) + pp->cmd.reply_len;
1210         if (count < size)
1211                 size = count;
1212         rc = size;
1213         hdr.status = pp->cmd.status;
1214         hdr.reply_len = pp->cmd.reply_len;
1215         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1216                 return -EFAULT;
1217         size -= sizeof(hdr);
1218         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1219                 return -EFAULT;
1220         pp->busy = 0;
1221
1222         return rc;
1223 }
1224
1225
1226 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1227                                char __user *buf, size_t count)
1228 {
1229         /* Not implemented */
1230         msleep_interruptible(1000);
1231         return 0;
1232 }
1233
1234
1235 static ssize_t smu_read(struct file *file, char __user *buf,
1236                         size_t count, loff_t *ppos)
1237 {
1238         struct smu_private *pp = file->private_data;
1239
1240         if (pp->mode == smu_file_commands)
1241                 return smu_read_command(file, pp, buf, count);
1242         if (pp->mode == smu_file_events)
1243                 return smu_read_events(file, pp, buf, count);
1244
1245         return -EBADFD;
1246 }
1247
1248 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1249 {
1250         struct smu_private *pp = file->private_data;
1251         unsigned int mask = 0;
1252         unsigned long flags;
1253
1254         if (pp == 0)
1255                 return 0;
1256
1257         if (pp->mode == smu_file_commands) {
1258                 poll_wait(file, &pp->wait, wait);
1259
1260                 spin_lock_irqsave(&pp->lock, flags);
1261                 if (pp->busy && pp->cmd.status != 1)
1262                         mask |= POLLIN;
1263                 spin_unlock_irqrestore(&pp->lock, flags);
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);