linux/drivers/macintosh/smu.c
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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/types.h>
  23#include <linux/kernel.h>
  24#include <linux/device.h>
  25#include <linux/dmapool.h>
  26#include <linux/bootmem.h>
  27#include <linux/vmalloc.h>
  28#include <linux/highmem.h>
  29#include <linux/jiffies.h>
  30#include <linux/interrupt.h>
  31#include <linux/rtc.h>
  32#include <linux/completion.h>
  33#include <linux/miscdevice.h>
  34#include <linux/delay.h>
  35#include <linux/poll.h>
  36#include <linux/mutex.h>
  37#include <linux/of_device.h>
  38#include <linux/of_platform.h>
  39#include <linux/slab.h>
  40
  41#include <asm/byteorder.h>
  42#include <asm/io.h>
  43#include <asm/prom.h>
  44#include <asm/machdep.h>
  45#include <asm/pmac_feature.h>
  46#include <asm/smu.h>
  47#include <asm/sections.h>
  48#include <asm/uaccess.h>
  49
  50#define VERSION "0.7"
  51#define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  52
  53#undef DEBUG_SMU
  54
  55#ifdef DEBUG_SMU
  56#define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  57#else
  58#define DPRINTK(fmt, args...) do { } while (0)
  59#endif
  60
  61/*
  62 * This is the command buffer passed to the SMU hardware
  63 */
  64#define SMU_MAX_DATA    254
  65
  66struct smu_cmd_buf {
  67        u8 cmd;
  68        u8 length;
  69        u8 data[SMU_MAX_DATA];
  70};
  71
  72struct smu_device {
  73        spinlock_t              lock;
  74        struct device_node      *of_node;
  75        struct platform_device  *of_dev;
  76        int                     doorbell;       /* doorbell gpio */
  77        u32 __iomem             *db_buf;        /* doorbell buffer */
  78        struct device_node      *db_node;
  79        unsigned int            db_irq;
  80        int                     msg;
  81        struct device_node      *msg_node;
  82        unsigned int            msg_irq;
  83        struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  84        u32                     cmd_buf_abs;    /* command buffer absolute */
  85        struct list_head        cmd_list;
  86        struct smu_cmd          *cmd_cur;       /* pending command */
  87        int                     broken_nap;
  88        struct list_head        cmd_i2c_list;
  89        struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  90        struct timer_list       i2c_timer;
  91};
  92
  93/*
  94 * I don't think there will ever be more than one SMU, so
  95 * for now, just hard code that
  96 */
  97static DEFINE_MUTEX(smu_mutex);
  98static struct smu_device        *smu;
  99static DEFINE_MUTEX(smu_part_access);
 100static int smu_irq_inited;
 101
 102static void smu_i2c_retry(unsigned long data);
 103
 104/*
 105 * SMU driver low level stuff
 106 */
 107
 108static void smu_start_cmd(void)
 109{
 110        unsigned long faddr, fend;
 111        struct smu_cmd *cmd;
 112
 113        if (list_empty(&smu->cmd_list))
 114                return;
 115
 116        /* Fetch first command in queue */
 117        cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 118        smu->cmd_cur = cmd;
 119        list_del(&cmd->link);
 120
 121        DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 122                cmd->data_len);
 123        DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 124                ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 125                ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 126                ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 127                ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 128
 129        /* Fill the SMU command buffer */
 130        smu->cmd_buf->cmd = cmd->cmd;
 131        smu->cmd_buf->length = cmd->data_len;
 132        memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 133
 134        /* Flush command and data to RAM */
 135        faddr = (unsigned long)smu->cmd_buf;
 136        fend = faddr + smu->cmd_buf->length + 2;
 137        flush_inval_dcache_range(faddr, fend);
 138
 139
 140        /* We also disable NAP mode for the duration of the command
 141         * on U3 based machines.
 142         * This is slightly racy as it can be written back to 1 by a sysctl
 143         * but that never happens in practice. There seem to be an issue with
 144         * U3 based machines such as the iMac G5 where napping for the
 145         * whole duration of the command prevents the SMU from fetching it
 146         * from memory. This might be related to the strange i2c based
 147         * mechanism the SMU uses to access memory.
 148         */
 149        if (smu->broken_nap)
 150                powersave_nap = 0;
 151
 152        /* This isn't exactly a DMA mapping here, I suspect
 153         * the SMU is actually communicating with us via i2c to the
 154         * northbridge or the CPU to access RAM.
 155         */
 156        writel(smu->cmd_buf_abs, smu->db_buf);
 157
 158        /* Ring the SMU doorbell */
 159        pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 160}
 161
 162
 163static irqreturn_t smu_db_intr(int irq, void *arg)
 164{
 165        unsigned long flags;
 166        struct smu_cmd *cmd;
 167        void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 168        void *misc = NULL;
 169        u8 gpio;
 170        int rc = 0;
 171
 172        /* SMU completed the command, well, we hope, let's make sure
 173         * of it
 174         */
 175        spin_lock_irqsave(&smu->lock, flags);
 176
 177        gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 178        if ((gpio & 7) != 7) {
 179                spin_unlock_irqrestore(&smu->lock, flags);
 180                return IRQ_HANDLED;
 181        }
 182
 183        cmd = smu->cmd_cur;
 184        smu->cmd_cur = NULL;
 185        if (cmd == NULL)
 186                goto bail;
 187
 188        if (rc == 0) {
 189                unsigned long faddr;
 190                int reply_len;
 191                u8 ack;
 192
 193                /* CPU might have brought back the cache line, so we need
 194                 * to flush again before peeking at the SMU response. We
 195                 * flush the entire buffer for now as we haven't read the
 196                 * reply length (it's only 2 cache lines anyway)
 197                 */
 198                faddr = (unsigned long)smu->cmd_buf;
 199                flush_inval_dcache_range(faddr, faddr + 256);
 200
 201                /* Now check ack */
 202                ack = (~cmd->cmd) & 0xff;
 203                if (ack != smu->cmd_buf->cmd) {
 204                        DPRINTK("SMU: incorrect ack, want %x got %x\n",
 205                                ack, smu->cmd_buf->cmd);
 206                        rc = -EIO;
 207                }
 208                reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 209                DPRINTK("SMU: reply len: %d\n", reply_len);
 210                if (reply_len > cmd->reply_len) {
 211                        printk(KERN_WARNING "SMU: reply buffer too small,"
 212                               "got %d bytes for a %d bytes buffer\n",
 213                               reply_len, cmd->reply_len);
 214                        reply_len = cmd->reply_len;
 215                }
 216                cmd->reply_len = reply_len;
 217                if (cmd->reply_buf && reply_len)
 218                        memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 219        }
 220
 221        /* Now complete the command. Write status last in order as we lost
 222         * ownership of the command structure as soon as it's no longer -1
 223         */
 224        done = cmd->done;
 225        misc = cmd->misc;
 226        mb();
 227        cmd->status = rc;
 228
 229        /* Re-enable NAP mode */
 230        if (smu->broken_nap)
 231                powersave_nap = 1;
 232 bail:
 233        /* Start next command if any */
 234        smu_start_cmd();
 235        spin_unlock_irqrestore(&smu->lock, flags);
 236
 237        /* Call command completion handler if any */
 238        if (done)
 239                done(cmd, misc);
 240
 241        /* It's an edge interrupt, nothing to do */
 242        return IRQ_HANDLED;
 243}
 244
 245
 246static irqreturn_t smu_msg_intr(int irq, void *arg)
 247{
 248        /* I don't quite know what to do with this one, we seem to never
 249         * receive it, so I suspect we have to arm it someway in the SMU
 250         * to start getting events that way.
 251         */
 252
 253        printk(KERN_INFO "SMU: message interrupt !\n");
 254
 255        /* It's an edge interrupt, nothing to do */
 256        return IRQ_HANDLED;
 257}
 258
 259
 260/*
 261 * Queued command management.
 262 *
 263 */
 264
 265int smu_queue_cmd(struct smu_cmd *cmd)
 266{
 267        unsigned long flags;
 268
 269        if (smu == NULL)
 270                return -ENODEV;
 271        if (cmd->data_len > SMU_MAX_DATA ||
 272            cmd->reply_len > SMU_MAX_DATA)
 273                return -EINVAL;
 274
 275        cmd->status = 1;
 276        spin_lock_irqsave(&smu->lock, flags);
 277        list_add_tail(&cmd->link, &smu->cmd_list);
 278        if (smu->cmd_cur == NULL)
 279                smu_start_cmd();
 280        spin_unlock_irqrestore(&smu->lock, flags);
 281
 282        /* Workaround for early calls when irq isn't available */
 283        if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 284                smu_spinwait_cmd(cmd);
 285
 286        return 0;
 287}
 288EXPORT_SYMBOL(smu_queue_cmd);
 289
 290
 291int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 292                     unsigned int data_len,
 293                     void (*done)(struct smu_cmd *cmd, void *misc),
 294                     void *misc, ...)
 295{
 296        struct smu_cmd *cmd = &scmd->cmd;
 297        va_list list;
 298        int i;
 299
 300        if (data_len > sizeof(scmd->buffer))
 301                return -EINVAL;
 302
 303        memset(scmd, 0, sizeof(*scmd));
 304        cmd->cmd = command;
 305        cmd->data_len = data_len;
 306        cmd->data_buf = scmd->buffer;
 307        cmd->reply_len = sizeof(scmd->buffer);
 308        cmd->reply_buf = scmd->buffer;
 309        cmd->done = done;
 310        cmd->misc = misc;
 311
 312        va_start(list, misc);
 313        for (i = 0; i < data_len; ++i)
 314                scmd->buffer[i] = (u8)va_arg(list, int);
 315        va_end(list);
 316
 317        return smu_queue_cmd(cmd);
 318}
 319EXPORT_SYMBOL(smu_queue_simple);
 320
 321
 322void smu_poll(void)
 323{
 324        u8 gpio;
 325
 326        if (smu == NULL)
 327                return;
 328
 329        gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 330        if ((gpio & 7) == 7)
 331                smu_db_intr(smu->db_irq, smu);
 332}
 333EXPORT_SYMBOL(smu_poll);
 334
 335
 336void smu_done_complete(struct smu_cmd *cmd, void *misc)
 337{
 338        struct completion *comp = misc;
 339
 340        complete(comp);
 341}
 342EXPORT_SYMBOL(smu_done_complete);
 343
 344
 345void smu_spinwait_cmd(struct smu_cmd *cmd)
 346{
 347        while(cmd->status == 1)
 348                smu_poll();
 349}
 350EXPORT_SYMBOL(smu_spinwait_cmd);
 351
 352
 353/* RTC low level commands */
 354static inline int bcd2hex (int n)
 355{
 356        return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 357}
 358
 359
 360static inline int hex2bcd (int n)
 361{
 362        return ((n / 10) << 4) + (n % 10);
 363}
 364
 365
 366static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 367                                        struct rtc_time *time)
 368{
 369        cmd_buf->cmd = 0x8e;
 370        cmd_buf->length = 8;
 371        cmd_buf->data[0] = 0x80;
 372        cmd_buf->data[1] = hex2bcd(time->tm_sec);
 373        cmd_buf->data[2] = hex2bcd(time->tm_min);
 374        cmd_buf->data[3] = hex2bcd(time->tm_hour);
 375        cmd_buf->data[4] = time->tm_wday;
 376        cmd_buf->data[5] = hex2bcd(time->tm_mday);
 377        cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 378        cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 379}
 380
 381
 382int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 383{
 384        struct smu_simple_cmd cmd;
 385        int rc;
 386
 387        if (smu == NULL)
 388                return -ENODEV;
 389
 390        memset(time, 0, sizeof(struct rtc_time));
 391        rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 392                              SMU_CMD_RTC_GET_DATETIME);
 393        if (rc)
 394                return rc;
 395        smu_spinwait_simple(&cmd);
 396
 397        time->tm_sec = bcd2hex(cmd.buffer[0]);
 398        time->tm_min = bcd2hex(cmd.buffer[1]);
 399        time->tm_hour = bcd2hex(cmd.buffer[2]);
 400        time->tm_wday = bcd2hex(cmd.buffer[3]);
 401        time->tm_mday = bcd2hex(cmd.buffer[4]);
 402        time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 403        time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 404
 405        return 0;
 406}
 407
 408
 409int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 410{
 411        struct smu_simple_cmd cmd;
 412        int rc;
 413
 414        if (smu == NULL)
 415                return -ENODEV;
 416
 417        rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 418                              SMU_CMD_RTC_SET_DATETIME,
 419                              hex2bcd(time->tm_sec),
 420                              hex2bcd(time->tm_min),
 421                              hex2bcd(time->tm_hour),
 422                              time->tm_wday,
 423                              hex2bcd(time->tm_mday),
 424                              hex2bcd(time->tm_mon) + 1,
 425                              hex2bcd(time->tm_year - 100));
 426        if (rc)
 427                return rc;
 428        smu_spinwait_simple(&cmd);
 429
 430        return 0;
 431}
 432
 433
 434void smu_shutdown(void)
 435{
 436        struct smu_simple_cmd cmd;
 437
 438        if (smu == NULL)
 439                return;
 440
 441        if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 442                             'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 443                return;
 444        smu_spinwait_simple(&cmd);
 445        for (;;)
 446                ;
 447}
 448
 449
 450void smu_restart(void)
 451{
 452        struct smu_simple_cmd cmd;
 453
 454        if (smu == NULL)
 455                return;
 456
 457        if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 458                             'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 459                return;
 460        smu_spinwait_simple(&cmd);
 461        for (;;)
 462                ;
 463}
 464
 465
 466int smu_present(void)
 467{
 468        return smu != NULL;
 469}
 470EXPORT_SYMBOL(smu_present);
 471
 472
 473int __init smu_init (void)
 474{
 475        struct device_node *np;
 476        const u32 *data;
 477        int ret = 0;
 478
 479        np = of_find_node_by_type(NULL, "smu");
 480        if (np == NULL)
 481                return -ENODEV;
 482
 483        printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 484
 485        if (smu_cmdbuf_abs == 0) {
 486                printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 487                ret = -EINVAL;
 488                goto fail_np;
 489        }
 490
 491        smu = alloc_bootmem(sizeof(struct smu_device));
 492
 493        spin_lock_init(&smu->lock);
 494        INIT_LIST_HEAD(&smu->cmd_list);
 495        INIT_LIST_HEAD(&smu->cmd_i2c_list);
 496        smu->of_node = np;
 497        smu->db_irq = NO_IRQ;
 498        smu->msg_irq = NO_IRQ;
 499
 500        /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 501         * 32 bits value safely
 502         */
 503        smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 504        smu->cmd_buf = __va(smu_cmdbuf_abs);
 505
 506        smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 507        if (smu->db_node == NULL) {
 508                printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 509                ret = -ENXIO;
 510                goto fail_bootmem;
 511        }
 512        data = of_get_property(smu->db_node, "reg", NULL);
 513        if (data == NULL) {
 514                printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 515                ret = -ENXIO;
 516                goto fail_db_node;
 517        }
 518
 519        /* Current setup has one doorbell GPIO that does both doorbell
 520         * and ack. GPIOs are at 0x50, best would be to find that out
 521         * in the device-tree though.
 522         */
 523        smu->doorbell = *data;
 524        if (smu->doorbell < 0x50)
 525                smu->doorbell += 0x50;
 526
 527        /* Now look for the smu-interrupt GPIO */
 528        do {
 529                smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 530                if (smu->msg_node == NULL)
 531                        break;
 532                data = of_get_property(smu->msg_node, "reg", NULL);
 533                if (data == NULL) {
 534                        of_node_put(smu->msg_node);
 535                        smu->msg_node = NULL;
 536                        break;
 537                }
 538                smu->msg = *data;
 539                if (smu->msg < 0x50)
 540                        smu->msg += 0x50;
 541        } while(0);
 542
 543        /* Doorbell buffer is currently hard-coded, I didn't find a proper
 544         * device-tree entry giving the address. Best would probably to use
 545         * an offset for K2 base though, but let's do it that way for now.
 546         */
 547        smu->db_buf = ioremap(0x8000860c, 0x1000);
 548        if (smu->db_buf == NULL) {
 549                printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 550                ret = -ENXIO;
 551                goto fail_msg_node;
 552        }
 553
 554        /* U3 has an issue with NAP mode when issuing SMU commands */
 555        smu->broken_nap = pmac_get_uninorth_variant() < 4;
 556        if (smu->broken_nap)
 557                printk(KERN_INFO "SMU: using NAP mode workaround\n");
 558
 559        sys_ctrler = SYS_CTRLER_SMU;
 560        return 0;
 561
 562fail_msg_node:
 563        if (smu->msg_node)
 564                of_node_put(smu->msg_node);
 565fail_db_node:
 566        of_node_put(smu->db_node);
 567fail_bootmem:
 568        free_bootmem((unsigned long)smu, sizeof(struct smu_device));
 569        smu = NULL;
 570fail_np:
 571        of_node_put(np);
 572        return ret;
 573}
 574
 575
 576static int smu_late_init(void)
 577{
 578        if (!smu)
 579                return 0;
 580
 581        init_timer(&smu->i2c_timer);
 582        smu->i2c_timer.function = smu_i2c_retry;
 583        smu->i2c_timer.data = (unsigned long)smu;
 584
 585        if (smu->db_node) {
 586                smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 587                if (smu->db_irq == NO_IRQ)
 588                        printk(KERN_ERR "smu: failed to map irq for node %s\n",
 589                               smu->db_node->full_name);
 590        }
 591        if (smu->msg_node) {
 592                smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 593                if (smu->msg_irq == NO_IRQ)
 594                        printk(KERN_ERR "smu: failed to map irq for node %s\n",
 595                               smu->msg_node->full_name);
 596        }
 597
 598        /*
 599         * Try to request the interrupts
 600         */
 601
 602        if (smu->db_irq != NO_IRQ) {
 603                if (request_irq(smu->db_irq, smu_db_intr,
 604                                IRQF_SHARED, "SMU doorbell", smu) < 0) {
 605                        printk(KERN_WARNING "SMU: can't "
 606                               "request interrupt %d\n",
 607                               smu->db_irq);
 608                        smu->db_irq = NO_IRQ;
 609                }
 610        }
 611
 612        if (smu->msg_irq != NO_IRQ) {
 613                if (request_irq(smu->msg_irq, smu_msg_intr,
 614                                IRQF_SHARED, "SMU message", smu) < 0) {
 615                        printk(KERN_WARNING "SMU: can't "
 616                               "request interrupt %d\n",
 617                               smu->msg_irq);
 618                        smu->msg_irq = NO_IRQ;
 619                }
 620        }
 621
 622        smu_irq_inited = 1;
 623        return 0;
 624}
 625/* This has to be before arch_initcall as the low i2c stuff relies on the
 626 * above having been done before we reach arch_initcalls
 627 */
 628core_initcall(smu_late_init);
 629
 630/*
 631 * sysfs visibility
 632 */
 633
 634static void smu_expose_childs(struct work_struct *unused)
 635{
 636        struct device_node *np;
 637
 638        for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 639                if (of_device_is_compatible(np, "smu-sensors"))
 640                        of_platform_device_create(np, "smu-sensors",
 641                                                  &smu->of_dev->dev);
 642}
 643
 644static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 645
 646static int smu_platform_probe(struct platform_device* dev)
 647{
 648        if (!smu)
 649                return -ENODEV;
 650        smu->of_dev = dev;
 651
 652        /*
 653         * Ok, we are matched, now expose all i2c busses. We have to defer
 654         * that unfortunately or it would deadlock inside the device model
 655         */
 656        schedule_work(&smu_expose_childs_work);
 657
 658        return 0;
 659}
 660
 661static const struct of_device_id smu_platform_match[] =
 662{
 663        {
 664                .type           = "smu",
 665        },
 666        {},
 667};
 668
 669static struct platform_driver smu_of_platform_driver =
 670{
 671        .driver = {
 672                .name = "smu",
 673                .owner = THIS_MODULE,
 674                .of_match_table = smu_platform_match,
 675        },
 676        .probe          = smu_platform_probe,
 677};
 678
 679static int __init smu_init_sysfs(void)
 680{
 681        /*
 682         * For now, we don't power manage machines with an SMU chip,
 683         * I'm a bit too far from figuring out how that works with those
 684         * new chipsets, but that will come back and bite us
 685         */
 686        platform_driver_register(&smu_of_platform_driver);
 687        return 0;
 688}
 689
 690device_initcall(smu_init_sysfs);
 691
 692struct platform_device *smu_get_ofdev(void)
 693{
 694        if (!smu)
 695                return NULL;
 696        return smu->of_dev;
 697}
 698
 699EXPORT_SYMBOL_GPL(smu_get_ofdev);
 700
 701/*
 702 * i2c interface
 703 */
 704
 705static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 706{
 707        void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 708        void *misc = cmd->misc;
 709        unsigned long flags;
 710
 711        /* Check for read case */
 712        if (!fail && cmd->read) {
 713                if (cmd->pdata[0] < 1)
 714                        fail = 1;
 715                else
 716                        memcpy(cmd->info.data, &cmd->pdata[1],
 717                               cmd->info.datalen);
 718        }
 719
 720        DPRINTK("SMU: completing, success: %d\n", !fail);
 721
 722        /* Update status and mark no pending i2c command with lock
 723         * held so nobody comes in while we dequeue an eventual
 724         * pending next i2c command
 725         */
 726        spin_lock_irqsave(&smu->lock, flags);
 727        smu->cmd_i2c_cur = NULL;
 728        wmb();
 729        cmd->status = fail ? -EIO : 0;
 730
 731        /* Is there another i2c command waiting ? */
 732        if (!list_empty(&smu->cmd_i2c_list)) {
 733                struct smu_i2c_cmd *newcmd;
 734
 735                /* Fetch it, new current, remove from list */
 736                newcmd = list_entry(smu->cmd_i2c_list.next,
 737                                    struct smu_i2c_cmd, link);
 738                smu->cmd_i2c_cur = newcmd;
 739                list_del(&cmd->link);
 740
 741                /* Queue with low level smu */
 742                list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 743                if (smu->cmd_cur == NULL)
 744                        smu_start_cmd();
 745        }
 746        spin_unlock_irqrestore(&smu->lock, flags);
 747
 748        /* Call command completion handler if any */
 749        if (done)
 750                done(cmd, misc);
 751
 752}
 753
 754
 755static void smu_i2c_retry(unsigned long data)
 756{
 757        struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 758
 759        DPRINTK("SMU: i2c failure, requeuing...\n");
 760
 761        /* requeue command simply by resetting reply_len */
 762        cmd->pdata[0] = 0xff;
 763        cmd->scmd.reply_len = sizeof(cmd->pdata);
 764        smu_queue_cmd(&cmd->scmd);
 765}
 766
 767
 768static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 769{
 770        struct smu_i2c_cmd      *cmd = misc;
 771        int                     fail = 0;
 772
 773        DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 774                cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 775
 776        /* Check for possible status */
 777        if (scmd->status < 0)
 778                fail = 1;
 779        else if (cmd->read) {
 780                if (cmd->stage == 0)
 781                        fail = cmd->pdata[0] != 0;
 782                else
 783                        fail = cmd->pdata[0] >= 0x80;
 784        } else {
 785                fail = cmd->pdata[0] != 0;
 786        }
 787
 788        /* Handle failures by requeuing command, after 5ms interval
 789         */
 790        if (fail && --cmd->retries > 0) {
 791                DPRINTK("SMU: i2c failure, starting timer...\n");
 792                BUG_ON(cmd != smu->cmd_i2c_cur);
 793                if (!smu_irq_inited) {
 794                        mdelay(5);
 795                        smu_i2c_retry(0);
 796                        return;
 797                }
 798                mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 799                return;
 800        }
 801
 802        /* If failure or stage 1, command is complete */
 803        if (fail || cmd->stage != 0) {
 804                smu_i2c_complete_command(cmd, fail);
 805                return;
 806        }
 807
 808        DPRINTK("SMU: going to stage 1\n");
 809
 810        /* Ok, initial command complete, now poll status */
 811        scmd->reply_buf = cmd->pdata;
 812        scmd->reply_len = sizeof(cmd->pdata);
 813        scmd->data_buf = cmd->pdata;
 814        scmd->data_len = 1;
 815        cmd->pdata[0] = 0;
 816        cmd->stage = 1;
 817        cmd->retries = 20;
 818        smu_queue_cmd(scmd);
 819}
 820
 821
 822int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 823{
 824        unsigned long flags;
 825
 826        if (smu == NULL)
 827                return -ENODEV;
 828
 829        /* Fill most fields of scmd */
 830        cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 831        cmd->scmd.done = smu_i2c_low_completion;
 832        cmd->scmd.misc = cmd;
 833        cmd->scmd.reply_buf = cmd->pdata;
 834        cmd->scmd.reply_len = sizeof(cmd->pdata);
 835        cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 836        cmd->scmd.status = 1;
 837        cmd->stage = 0;
 838        cmd->pdata[0] = 0xff;
 839        cmd->retries = 20;
 840        cmd->status = 1;
 841
 842        /* Check transfer type, sanitize some "info" fields
 843         * based on transfer type and do more checking
 844         */
 845        cmd->info.caddr = cmd->info.devaddr;
 846        cmd->read = cmd->info.devaddr & 0x01;
 847        switch(cmd->info.type) {
 848        case SMU_I2C_TRANSFER_SIMPLE:
 849                memset(&cmd->info.sublen, 0, 4);
 850                break;
 851        case SMU_I2C_TRANSFER_COMBINED:
 852                cmd->info.devaddr &= 0xfe;
 853        case SMU_I2C_TRANSFER_STDSUB:
 854                if (cmd->info.sublen > 3)
 855                        return -EINVAL;
 856                break;
 857        default:
 858                return -EINVAL;
 859        }
 860
 861        /* Finish setting up command based on transfer direction
 862         */
 863        if (cmd->read) {
 864                if (cmd->info.datalen > SMU_I2C_READ_MAX)
 865                        return -EINVAL;
 866                memset(cmd->info.data, 0xff, cmd->info.datalen);
 867                cmd->scmd.data_len = 9;
 868        } else {
 869                if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 870                        return -EINVAL;
 871                cmd->scmd.data_len = 9 + cmd->info.datalen;
 872        }
 873
 874        DPRINTK("SMU: i2c enqueuing command\n");
 875        DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 876                cmd->read ? "read" : "write", cmd->info.datalen,
 877                cmd->info.bus, cmd->info.caddr,
 878                cmd->info.subaddr[0], cmd->info.type);
 879
 880
 881        /* Enqueue command in i2c list, and if empty, enqueue also in
 882         * main command list
 883         */
 884        spin_lock_irqsave(&smu->lock, flags);
 885        if (smu->cmd_i2c_cur == NULL) {
 886                smu->cmd_i2c_cur = cmd;
 887                list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 888                if (smu->cmd_cur == NULL)
 889                        smu_start_cmd();
 890        } else
 891                list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 892        spin_unlock_irqrestore(&smu->lock, flags);
 893
 894        return 0;
 895}
 896
 897/*
 898 * Handling of "partitions"
 899 */
 900
 901static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 902{
 903        DECLARE_COMPLETION_ONSTACK(comp);
 904        unsigned int chunk;
 905        struct smu_cmd cmd;
 906        int rc;
 907        u8 params[8];
 908
 909        /* We currently use a chunk size of 0xe. We could check the
 910         * SMU firmware version and use bigger sizes though
 911         */
 912        chunk = 0xe;
 913
 914        while (len) {
 915                unsigned int clen = min(len, chunk);
 916
 917                cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 918                cmd.data_len = 7;
 919                cmd.data_buf = params;
 920                cmd.reply_len = chunk;
 921                cmd.reply_buf = dest;
 922                cmd.done = smu_done_complete;
 923                cmd.misc = &comp;
 924                params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 925                params[1] = 0x4;
 926                *((u32 *)&params[2]) = addr;
 927                params[6] = clen;
 928
 929                rc = smu_queue_cmd(&cmd);
 930                if (rc)
 931                        return rc;
 932                wait_for_completion(&comp);
 933                if (cmd.status != 0)
 934                        return rc;
 935                if (cmd.reply_len != clen) {
 936                        printk(KERN_DEBUG "SMU: short read in "
 937                               "smu_read_datablock, got: %d, want: %d\n",
 938                               cmd.reply_len, clen);
 939                        return -EIO;
 940                }
 941                len -= clen;
 942                addr += clen;
 943                dest += clen;
 944        }
 945        return 0;
 946}
 947
 948static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 949{
 950        DECLARE_COMPLETION_ONSTACK(comp);
 951        struct smu_simple_cmd cmd;
 952        unsigned int addr, len, tlen;
 953        struct smu_sdbp_header *hdr;
 954        struct property *prop;
 955
 956        /* First query the partition info */
 957        DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 958        smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 959                         smu_done_complete, &comp,
 960                         SMU_CMD_PARTITION_LATEST, id);
 961        wait_for_completion(&comp);
 962        DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 963                cmd.cmd.status, cmd.cmd.reply_len);
 964
 965        /* Partition doesn't exist (or other error) */
 966        if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 967                return NULL;
 968
 969        /* Fetch address and length from reply */
 970        addr = *((u16 *)cmd.buffer);
 971        len = cmd.buffer[3] << 2;
 972        /* Calucluate total length to allocate, including the 17 bytes
 973         * for "sdb-partition-XX" that we append at the end of the buffer
 974         */
 975        tlen = sizeof(struct property) + len + 18;
 976
 977        prop = kzalloc(tlen, GFP_KERNEL);
 978        if (prop == NULL)
 979                return NULL;
 980        hdr = (struct smu_sdbp_header *)(prop + 1);
 981        prop->name = ((char *)prop) + tlen - 18;
 982        sprintf(prop->name, "sdb-partition-%02x", id);
 983        prop->length = len;
 984        prop->value = hdr;
 985        prop->next = NULL;
 986
 987        /* Read the datablock */
 988        if (smu_read_datablock((u8 *)hdr, addr, len)) {
 989                printk(KERN_DEBUG "SMU: datablock read failed while reading "
 990                       "partition %02x !\n", id);
 991                goto failure;
 992        }
 993
 994        /* Got it, check a few things and create the property */
 995        if (hdr->id != id) {
 996                printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 997                       "%02x !\n", id, hdr->id);
 998                goto failure;
 999        }
1000        if (prom_add_property(smu->of_node, prop)) {
1001                printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1002                       "property !\n", id);
1003                goto failure;
1004        }
1005
1006        return hdr;
1007 failure:
1008        kfree(prop);
1009        return NULL;
1010}
1011
1012/* Note: Only allowed to return error code in pointers (using ERR_PTR)
1013 * when interruptible is 1
1014 */
1015const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1016                unsigned int *size, int interruptible)
1017{
1018        char pname[32];
1019        const struct smu_sdbp_header *part;
1020
1021        if (!smu)
1022                return NULL;
1023
1024        sprintf(pname, "sdb-partition-%02x", id);
1025
1026        DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1027
1028        if (interruptible) {
1029                int rc;
1030                rc = mutex_lock_interruptible(&smu_part_access);
1031                if (rc)
1032                        return ERR_PTR(rc);
1033        } else
1034                mutex_lock(&smu_part_access);
1035
1036        part = of_get_property(smu->of_node, pname, size);
1037        if (part == NULL) {
1038                DPRINTK("trying to extract from SMU ...\n");
1039                part = smu_create_sdb_partition(id);
1040                if (part != NULL && size)
1041                        *size = part->len << 2;
1042        }
1043        mutex_unlock(&smu_part_access);
1044        return part;
1045}
1046
1047const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1048{
1049        return __smu_get_sdb_partition(id, size, 0);
1050}
1051EXPORT_SYMBOL(smu_get_sdb_partition);
1052
1053
1054/*
1055 * Userland driver interface
1056 */
1057
1058
1059static LIST_HEAD(smu_clist);
1060static DEFINE_SPINLOCK(smu_clist_lock);
1061
1062enum smu_file_mode {
1063        smu_file_commands,
1064        smu_file_events,
1065        smu_file_closing
1066};
1067
1068struct smu_private
1069{
1070        struct list_head        list;
1071        enum smu_file_mode      mode;
1072        int                     busy;
1073        struct smu_cmd          cmd;
1074        spinlock_t              lock;
1075        wait_queue_head_t       wait;
1076        u8                      buffer[SMU_MAX_DATA];
1077};
1078
1079
1080static int smu_open(struct inode *inode, struct file *file)
1081{
1082        struct smu_private *pp;
1083        unsigned long flags;
1084
1085        pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1086        if (pp == 0)
1087                return -ENOMEM;
1088        spin_lock_init(&pp->lock);
1089        pp->mode = smu_file_commands;
1090        init_waitqueue_head(&pp->wait);
1091
1092        mutex_lock(&smu_mutex);
1093        spin_lock_irqsave(&smu_clist_lock, flags);
1094        list_add(&pp->list, &smu_clist);
1095        spin_unlock_irqrestore(&smu_clist_lock, flags);
1096        file->private_data = pp;
1097        mutex_unlock(&smu_mutex);
1098
1099        return 0;
1100}
1101
1102
1103static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1104{
1105        struct smu_private *pp = misc;
1106
1107        wake_up_all(&pp->wait);
1108}
1109
1110
1111static ssize_t smu_write(struct file *file, const char __user *buf,
1112                         size_t count, loff_t *ppos)
1113{
1114        struct smu_private *pp = file->private_data;
1115        unsigned long flags;
1116        struct smu_user_cmd_hdr hdr;
1117        int rc = 0;
1118
1119        if (pp->busy)
1120                return -EBUSY;
1121        else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1122                return -EFAULT;
1123        else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1124                pp->mode = smu_file_events;
1125                return 0;
1126        } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1127                const struct smu_sdbp_header *part;
1128                part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1129                if (part == NULL)
1130                        return -EINVAL;
1131                else if (IS_ERR(part))
1132                        return PTR_ERR(part);
1133                return 0;
1134        } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1135                return -EINVAL;
1136        else if (pp->mode != smu_file_commands)
1137                return -EBADFD;
1138        else if (hdr.data_len > SMU_MAX_DATA)
1139                return -EINVAL;
1140
1141        spin_lock_irqsave(&pp->lock, flags);
1142        if (pp->busy) {
1143                spin_unlock_irqrestore(&pp->lock, flags);
1144                return -EBUSY;
1145        }
1146        pp->busy = 1;
1147        pp->cmd.status = 1;
1148        spin_unlock_irqrestore(&pp->lock, flags);
1149
1150        if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1151                pp->busy = 0;
1152                return -EFAULT;
1153        }
1154
1155        pp->cmd.cmd = hdr.cmd;
1156        pp->cmd.data_len = hdr.data_len;
1157        pp->cmd.reply_len = SMU_MAX_DATA;
1158        pp->cmd.data_buf = pp->buffer;
1159        pp->cmd.reply_buf = pp->buffer;
1160        pp->cmd.done = smu_user_cmd_done;
1161        pp->cmd.misc = pp;
1162        rc = smu_queue_cmd(&pp->cmd);
1163        if (rc < 0)
1164                return rc;
1165        return count;
1166}
1167
1168
1169static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1170                                char __user *buf, size_t count)
1171{
1172        DECLARE_WAITQUEUE(wait, current);
1173        struct smu_user_reply_hdr hdr;
1174        unsigned long flags;
1175        int size, rc = 0;
1176
1177        if (!pp->busy)
1178                return 0;
1179        if (count < sizeof(struct smu_user_reply_hdr))
1180                return -EOVERFLOW;
1181        spin_lock_irqsave(&pp->lock, flags);
1182        if (pp->cmd.status == 1) {
1183                if (file->f_flags & O_NONBLOCK) {
1184                        spin_unlock_irqrestore(&pp->lock, flags);
1185                        return -EAGAIN;
1186                }
1187                add_wait_queue(&pp->wait, &wait);
1188                for (;;) {
1189                        set_current_state(TASK_INTERRUPTIBLE);
1190                        rc = 0;
1191                        if (pp->cmd.status != 1)
1192                                break;
1193                        rc = -ERESTARTSYS;
1194                        if (signal_pending(current))
1195                                break;
1196                        spin_unlock_irqrestore(&pp->lock, flags);
1197                        schedule();
1198                        spin_lock_irqsave(&pp->lock, flags);
1199                }
1200                set_current_state(TASK_RUNNING);
1201                remove_wait_queue(&pp->wait, &wait);
1202        }
1203        spin_unlock_irqrestore(&pp->lock, flags);
1204        if (rc)
1205                return rc;
1206        if (pp->cmd.status != 0)
1207                pp->cmd.reply_len = 0;
1208        size = sizeof(hdr) + pp->cmd.reply_len;
1209        if (count < size)
1210                size = count;
1211        rc = size;
1212        hdr.status = pp->cmd.status;
1213        hdr.reply_len = pp->cmd.reply_len;
1214        if (copy_to_user(buf, &hdr, sizeof(hdr)))
1215                return -EFAULT;
1216        size -= sizeof(hdr);
1217        if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1218                return -EFAULT;
1219        pp->busy = 0;
1220
1221        return rc;
1222}
1223
1224
1225static 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
1234static 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
1247static 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
1269static 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
1312static 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
1321static struct miscdevice pmu_device = {
1322        MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1323};
1324
1325static 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}
1333device_initcall(smu_device_init);
1334
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