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