linux/drivers/macintosh/smu.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * PowerMac G5 SMU driver
   4 *
   5 * Copyright 2004 J. Mayer <l_indien@magic.fr>
   6 * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   7 */
   8
   9/*
  10 * TODO:
  11 *  - maybe add timeout to commands ?
  12 *  - blocking version of time functions
  13 *  - polling version of i2c commands (including timer that works with
  14 *    interrupts off)
  15 *  - maybe avoid some data copies with i2c by directly using the smu cmd
  16 *    buffer and a lower level internal interface
  17 *  - understand SMU -> CPU events and implement reception of them via
  18 *    the userland interface
  19 */
  20
  21#include <linux/types.h>
  22#include <linux/kernel.h>
  23#include <linux/device.h>
  24#include <linux/dmapool.h>
  25#include <linux/memblock.h>
  26#include <linux/vmalloc.h>
  27#include <linux/highmem.h>
  28#include <linux/jiffies.h>
  29#include <linux/interrupt.h>
  30#include <linux/rtc.h>
  31#include <linux/completion.h>
  32#include <linux/miscdevice.h>
  33#include <linux/delay.h>
  34#include <linux/poll.h>
  35#include <linux/mutex.h>
  36#include <linux/of_device.h>
  37#include <linux/of_irq.h>
  38#include <linux/of_platform.h>
  39#include <linux/slab.h>
  40#include <linux/sched/signal.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 <linux/uaccess.h>
  50
  51#define VERSION "0.7"
  52#define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  53
  54#undef DEBUG_SMU
  55
  56#ifdef DEBUG_SMU
  57#define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  58#else
  59#define DPRINTK(fmt, args...) do { } while (0)
  60#endif
  61
  62/*
  63 * This is the command buffer passed to the SMU hardware
  64 */
  65#define SMU_MAX_DATA    254
  66
  67struct smu_cmd_buf {
  68        u8 cmd;
  69        u8 length;
  70        u8 data[SMU_MAX_DATA];
  71};
  72
  73struct smu_device {
  74        spinlock_t              lock;
  75        struct device_node      *of_node;
  76        struct platform_device  *of_dev;
  77        int                     doorbell;       /* doorbell gpio */
  78        u32 __iomem             *db_buf;        /* doorbell buffer */
  79        struct device_node      *db_node;
  80        unsigned int            db_irq;
  81        int                     msg;
  82        struct device_node      *msg_node;
  83        unsigned int            msg_irq;
  84        struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  85        u32                     cmd_buf_abs;    /* command buffer absolute */
  86        struct list_head        cmd_list;
  87        struct smu_cmd          *cmd_cur;       /* pending command */
  88        int                     broken_nap;
  89        struct list_head        cmd_i2c_list;
  90        struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  91        struct timer_list       i2c_timer;
  92};
  93
  94/*
  95 * I don't think there will ever be more than one SMU, so
  96 * for now, just hard code that
  97 */
  98static DEFINE_MUTEX(smu_mutex);
  99static struct smu_device        *smu;
 100static DEFINE_MUTEX(smu_part_access);
 101static int smu_irq_inited;
 102static unsigned long smu_cmdbuf_abs;
 103
 104static void smu_i2c_retry(struct timer_list *t);
 105
 106/*
 107 * SMU driver low level stuff
 108 */
 109
 110static void smu_start_cmd(void)
 111{
 112        unsigned long faddr, fend;
 113        struct smu_cmd *cmd;
 114
 115        if (list_empty(&smu->cmd_list))
 116                return;
 117
 118        /* Fetch first command in queue */
 119        cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 120        smu->cmd_cur = cmd;
 121        list_del(&cmd->link);
 122
 123        DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 124                cmd->data_len);
 125        DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf);
 126
 127        /* Fill the SMU command buffer */
 128        smu->cmd_buf->cmd = cmd->cmd;
 129        smu->cmd_buf->length = cmd->data_len;
 130        memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 131
 132        /* Flush command and data to RAM */
 133        faddr = (unsigned long)smu->cmd_buf;
 134        fend = faddr + smu->cmd_buf->length + 2;
 135        flush_dcache_range(faddr, fend);
 136
 137
 138        /* We also disable NAP mode for the duration of the command
 139         * on U3 based machines.
 140         * This is slightly racy as it can be written back to 1 by a sysctl
 141         * but that never happens in practice. There seem to be an issue with
 142         * U3 based machines such as the iMac G5 where napping for the
 143         * whole duration of the command prevents the SMU from fetching it
 144         * from memory. This might be related to the strange i2c based
 145         * mechanism the SMU uses to access memory.
 146         */
 147        if (smu->broken_nap)
 148                powersave_nap = 0;
 149
 150        /* This isn't exactly a DMA mapping here, I suspect
 151         * the SMU is actually communicating with us via i2c to the
 152         * northbridge or the CPU to access RAM.
 153         */
 154        writel(smu->cmd_buf_abs, smu->db_buf);
 155
 156        /* Ring the SMU doorbell */
 157        pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 158}
 159
 160
 161static irqreturn_t smu_db_intr(int irq, void *arg)
 162{
 163        unsigned long flags;
 164        struct smu_cmd *cmd;
 165        void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 166        void *misc = NULL;
 167        u8 gpio;
 168        int rc = 0;
 169
 170        /* SMU completed the command, well, we hope, let's make sure
 171         * of it
 172         */
 173        spin_lock_irqsave(&smu->lock, flags);
 174
 175        gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 176        if ((gpio & 7) != 7) {
 177                spin_unlock_irqrestore(&smu->lock, flags);
 178                return IRQ_HANDLED;
 179        }
 180
 181        cmd = smu->cmd_cur;
 182        smu->cmd_cur = NULL;
 183        if (cmd == NULL)
 184                goto bail;
 185
 186        if (rc == 0) {
 187                unsigned long faddr;
 188                int reply_len;
 189                u8 ack;
 190
 191                /* CPU might have brought back the cache line, so we need
 192                 * to flush again before peeking at the SMU response. We
 193                 * flush the entire buffer for now as we haven't read the
 194                 * reply length (it's only 2 cache lines anyway)
 195                 */
 196                faddr = (unsigned long)smu->cmd_buf;
 197                flush_dcache_range(faddr, faddr + 256);
 198
 199                /* Now check ack */
 200                ack = (~cmd->cmd) & 0xff;
 201                if (ack != smu->cmd_buf->cmd) {
 202                        DPRINTK("SMU: incorrect ack, want %x got %x\n",
 203                                ack, smu->cmd_buf->cmd);
 204                        rc = -EIO;
 205                }
 206                reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 207                DPRINTK("SMU: reply len: %d\n", reply_len);
 208                if (reply_len > cmd->reply_len) {
 209                        printk(KERN_WARNING "SMU: reply buffer too small,"
 210                               "got %d bytes for a %d bytes buffer\n",
 211                               reply_len, cmd->reply_len);
 212                        reply_len = cmd->reply_len;
 213                }
 214                cmd->reply_len = reply_len;
 215                if (cmd->reply_buf && reply_len)
 216                        memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 217        }
 218
 219        /* Now complete the command. Write status last in order as we lost
 220         * ownership of the command structure as soon as it's no longer -1
 221         */
 222        done = cmd->done;
 223        misc = cmd->misc;
 224        mb();
 225        cmd->status = rc;
 226
 227        /* Re-enable NAP mode */
 228        if (smu->broken_nap)
 229                powersave_nap = 1;
 230 bail:
 231        /* Start next command if any */
 232        smu_start_cmd();
 233        spin_unlock_irqrestore(&smu->lock, flags);
 234
 235        /* Call command completion handler if any */
 236        if (done)
 237                done(cmd, misc);
 238
 239        /* It's an edge interrupt, nothing to do */
 240        return IRQ_HANDLED;
 241}
 242
 243
 244static irqreturn_t smu_msg_intr(int irq, void *arg)
 245{
 246        /* I don't quite know what to do with this one, we seem to never
 247         * receive it, so I suspect we have to arm it someway in the SMU
 248         * to start getting events that way.
 249         */
 250
 251        printk(KERN_INFO "SMU: message interrupt !\n");
 252
 253        /* It's an edge interrupt, nothing to do */
 254        return IRQ_HANDLED;
 255}
 256
 257
 258/*
 259 * Queued command management.
 260 *
 261 */
 262
 263int smu_queue_cmd(struct smu_cmd *cmd)
 264{
 265        unsigned long flags;
 266
 267        if (smu == NULL)
 268                return -ENODEV;
 269        if (cmd->data_len > SMU_MAX_DATA ||
 270            cmd->reply_len > SMU_MAX_DATA)
 271                return -EINVAL;
 272
 273        cmd->status = 1;
 274        spin_lock_irqsave(&smu->lock, flags);
 275        list_add_tail(&cmd->link, &smu->cmd_list);
 276        if (smu->cmd_cur == NULL)
 277                smu_start_cmd();
 278        spin_unlock_irqrestore(&smu->lock, flags);
 279
 280        /* Workaround for early calls when irq isn't available */
 281        if (!smu_irq_inited || !smu->db_irq)
 282                smu_spinwait_cmd(cmd);
 283
 284        return 0;
 285}
 286EXPORT_SYMBOL(smu_queue_cmd);
 287
 288
 289int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 290                     unsigned int data_len,
 291                     void (*done)(struct smu_cmd *cmd, void *misc),
 292                     void *misc, ...)
 293{
 294        struct smu_cmd *cmd = &scmd->cmd;
 295        va_list list;
 296        int i;
 297
 298        if (data_len > sizeof(scmd->buffer))
 299                return -EINVAL;
 300
 301        memset(scmd, 0, sizeof(*scmd));
 302        cmd->cmd = command;
 303        cmd->data_len = data_len;
 304        cmd->data_buf = scmd->buffer;
 305        cmd->reply_len = sizeof(scmd->buffer);
 306        cmd->reply_buf = scmd->buffer;
 307        cmd->done = done;
 308        cmd->misc = misc;
 309
 310        va_start(list, misc);
 311        for (i = 0; i < data_len; ++i)
 312                scmd->buffer[i] = (u8)va_arg(list, int);
 313        va_end(list);
 314
 315        return smu_queue_cmd(cmd);
 316}
 317EXPORT_SYMBOL(smu_queue_simple);
 318
 319
 320void smu_poll(void)
 321{
 322        u8 gpio;
 323
 324        if (smu == NULL)
 325                return;
 326
 327        gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 328        if ((gpio & 7) == 7)
 329                smu_db_intr(smu->db_irq, smu);
 330}
 331EXPORT_SYMBOL(smu_poll);
 332
 333
 334void smu_done_complete(struct smu_cmd *cmd, void *misc)
 335{
 336        struct completion *comp = misc;
 337
 338        complete(comp);
 339}
 340EXPORT_SYMBOL(smu_done_complete);
 341
 342
 343void smu_spinwait_cmd(struct smu_cmd *cmd)
 344{
 345        while(cmd->status == 1)
 346                smu_poll();
 347}
 348EXPORT_SYMBOL(smu_spinwait_cmd);
 349
 350
 351/* RTC low level commands */
 352static inline int bcd2hex (int n)
 353{
 354        return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 355}
 356
 357
 358static inline int hex2bcd (int n)
 359{
 360        return ((n / 10) << 4) + (n % 10);
 361}
 362
 363
 364static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 365                                        struct rtc_time *time)
 366{
 367        cmd_buf->cmd = 0x8e;
 368        cmd_buf->length = 8;
 369        cmd_buf->data[0] = 0x80;
 370        cmd_buf->data[1] = hex2bcd(time->tm_sec);
 371        cmd_buf->data[2] = hex2bcd(time->tm_min);
 372        cmd_buf->data[3] = hex2bcd(time->tm_hour);
 373        cmd_buf->data[4] = time->tm_wday;
 374        cmd_buf->data[5] = hex2bcd(time->tm_mday);
 375        cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 376        cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 377}
 378
 379
 380int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 381{
 382        struct smu_simple_cmd cmd;
 383        int rc;
 384
 385        if (smu == NULL)
 386                return -ENODEV;
 387
 388        memset(time, 0, sizeof(struct rtc_time));
 389        rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 390                              SMU_CMD_RTC_GET_DATETIME);
 391        if (rc)
 392                return rc;
 393        smu_spinwait_simple(&cmd);
 394
 395        time->tm_sec = bcd2hex(cmd.buffer[0]);
 396        time->tm_min = bcd2hex(cmd.buffer[1]);
 397        time->tm_hour = bcd2hex(cmd.buffer[2]);
 398        time->tm_wday = bcd2hex(cmd.buffer[3]);
 399        time->tm_mday = bcd2hex(cmd.buffer[4]);
 400        time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 401        time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 402
 403        return 0;
 404}
 405
 406
 407int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 408{
 409        struct smu_simple_cmd cmd;
 410        int rc;
 411
 412        if (smu == NULL)
 413                return -ENODEV;
 414
 415        rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 416                              SMU_CMD_RTC_SET_DATETIME,
 417                              hex2bcd(time->tm_sec),
 418                              hex2bcd(time->tm_min),
 419                              hex2bcd(time->tm_hour),
 420                              time->tm_wday,
 421                              hex2bcd(time->tm_mday),
 422                              hex2bcd(time->tm_mon) + 1,
 423                              hex2bcd(time->tm_year - 100));
 424        if (rc)
 425                return rc;
 426        smu_spinwait_simple(&cmd);
 427
 428        return 0;
 429}
 430
 431
 432void smu_shutdown(void)
 433{
 434        struct smu_simple_cmd cmd;
 435
 436        if (smu == NULL)
 437                return;
 438
 439        if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 440                             'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 441                return;
 442        smu_spinwait_simple(&cmd);
 443        for (;;)
 444                ;
 445}
 446
 447
 448void smu_restart(void)
 449{
 450        struct smu_simple_cmd cmd;
 451
 452        if (smu == NULL)
 453                return;
 454
 455        if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 456                             'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 457                return;
 458        smu_spinwait_simple(&cmd);
 459        for (;;)
 460                ;
 461}
 462
 463
 464int smu_present(void)
 465{
 466        return smu != NULL;
 467}
 468EXPORT_SYMBOL(smu_present);
 469
 470
 471int __init smu_init (void)
 472{
 473        struct device_node *np;
 474        const u32 *data;
 475        int ret = 0;
 476
 477        np = of_find_node_by_type(NULL, "smu");
 478        if (np == NULL)
 479                return -ENODEV;
 480
 481        printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 482
 483        /*
 484         * SMU based G5s need some memory below 2Gb. Thankfully this is
 485         * called at a time where memblock is still available.
 486         */
 487        smu_cmdbuf_abs = memblock_phys_alloc_range(4096, 4096, 0, 0x80000000UL);
 488        if (smu_cmdbuf_abs == 0) {
 489                printk(KERN_ERR "SMU: Command buffer allocation failed !\n");
 490                ret = -EINVAL;
 491                goto fail_np;
 492        }
 493
 494        smu = memblock_alloc(sizeof(struct smu_device), SMP_CACHE_BYTES);
 495        if (!smu)
 496                panic("%s: Failed to allocate %zu bytes\n", __func__,
 497                      sizeof(struct smu_device));
 498
 499        spin_lock_init(&smu->lock);
 500        INIT_LIST_HEAD(&smu->cmd_list);
 501        INIT_LIST_HEAD(&smu->cmd_i2c_list);
 502        smu->of_node = np;
 503        smu->db_irq = 0;
 504        smu->msg_irq = 0;
 505
 506        /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 507         * 32 bits value safely
 508         */
 509        smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 510        smu->cmd_buf = __va(smu_cmdbuf_abs);
 511
 512        smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 513        if (smu->db_node == NULL) {
 514                printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 515                ret = -ENXIO;
 516                goto fail_bootmem;
 517        }
 518        data = of_get_property(smu->db_node, "reg", NULL);
 519        if (data == NULL) {
 520                printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 521                ret = -ENXIO;
 522                goto fail_db_node;
 523        }
 524
 525        /* Current setup has one doorbell GPIO that does both doorbell
 526         * and ack. GPIOs are at 0x50, best would be to find that out
 527         * in the device-tree though.
 528         */
 529        smu->doorbell = *data;
 530        if (smu->doorbell < 0x50)
 531                smu->doorbell += 0x50;
 532
 533        /* Now look for the smu-interrupt GPIO */
 534        do {
 535                smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 536                if (smu->msg_node == NULL)
 537                        break;
 538                data = of_get_property(smu->msg_node, "reg", NULL);
 539                if (data == NULL) {
 540                        of_node_put(smu->msg_node);
 541                        smu->msg_node = NULL;
 542                        break;
 543                }
 544                smu->msg = *data;
 545                if (smu->msg < 0x50)
 546                        smu->msg += 0x50;
 547        } while(0);
 548
 549        /* Doorbell buffer is currently hard-coded, I didn't find a proper
 550         * device-tree entry giving the address. Best would probably to use
 551         * an offset for K2 base though, but let's do it that way for now.
 552         */
 553        smu->db_buf = ioremap(0x8000860c, 0x1000);
 554        if (smu->db_buf == NULL) {
 555                printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 556                ret = -ENXIO;
 557                goto fail_msg_node;
 558        }
 559
 560        /* U3 has an issue with NAP mode when issuing SMU commands */
 561        smu->broken_nap = pmac_get_uninorth_variant() < 4;
 562        if (smu->broken_nap)
 563                printk(KERN_INFO "SMU: using NAP mode workaround\n");
 564
 565        sys_ctrler = SYS_CTRLER_SMU;
 566        return 0;
 567
 568fail_msg_node:
 569        of_node_put(smu->msg_node);
 570fail_db_node:
 571        of_node_put(smu->db_node);
 572fail_bootmem:
 573        memblock_free(__pa(smu), sizeof(struct smu_device));
 574        smu = NULL;
 575fail_np:
 576        of_node_put(np);
 577        return ret;
 578}
 579
 580
 581static int smu_late_init(void)
 582{
 583        if (!smu)
 584                return 0;
 585
 586        timer_setup(&smu->i2c_timer, smu_i2c_retry, 0);
 587
 588        if (smu->db_node) {
 589                smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 590                if (!smu->db_irq)
 591                        printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 592                               smu->db_node);
 593        }
 594        if (smu->msg_node) {
 595                smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 596                if (!smu->msg_irq)
 597                        printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 598                               smu->msg_node);
 599        }
 600
 601        /*
 602         * Try to request the interrupts
 603         */
 604
 605        if (smu->db_irq) {
 606                if (request_irq(smu->db_irq, smu_db_intr,
 607                                IRQF_SHARED, "SMU doorbell", smu) < 0) {
 608                        printk(KERN_WARNING "SMU: can't "
 609                               "request interrupt %d\n",
 610                               smu->db_irq);
 611                        smu->db_irq = 0;
 612                }
 613        }
 614
 615        if (smu->msg_irq) {
 616                if (request_irq(smu->msg_irq, smu_msg_intr,
 617                                IRQF_SHARED, "SMU message", smu) < 0) {
 618                        printk(KERN_WARNING "SMU: can't "
 619                               "request interrupt %d\n",
 620                               smu->msg_irq);
 621                        smu->msg_irq = 0;
 622                }
 623        }
 624
 625        smu_irq_inited = 1;
 626        return 0;
 627}
 628/* This has to be before arch_initcall as the low i2c stuff relies on the
 629 * above having been done before we reach arch_initcalls
 630 */
 631core_initcall(smu_late_init);
 632
 633/*
 634 * sysfs visibility
 635 */
 636
 637static void smu_expose_childs(struct work_struct *unused)
 638{
 639        struct device_node *np;
 640
 641        for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 642                if (of_device_is_compatible(np, "smu-sensors"))
 643                        of_platform_device_create(np, "smu-sensors",
 644                                                  &smu->of_dev->dev);
 645}
 646
 647static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 648
 649static int smu_platform_probe(struct platform_device* dev)
 650{
 651        if (!smu)
 652                return -ENODEV;
 653        smu->of_dev = dev;
 654
 655        /*
 656         * Ok, we are matched, now expose all i2c busses. We have to defer
 657         * that unfortunately or it would deadlock inside the device model
 658         */
 659        schedule_work(&smu_expose_childs_work);
 660
 661        return 0;
 662}
 663
 664static const struct of_device_id smu_platform_match[] =
 665{
 666        {
 667                .type           = "smu",
 668        },
 669        {},
 670};
 671
 672static struct platform_driver smu_of_platform_driver =
 673{
 674        .driver = {
 675                .name = "smu",
 676                .of_match_table = smu_platform_match,
 677        },
 678        .probe          = smu_platform_probe,
 679};
 680
 681static int __init smu_init_sysfs(void)
 682{
 683        /*
 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        platform_driver_register(&smu_of_platform_driver);
 689        return 0;
 690}
 691
 692device_initcall(smu_init_sysfs);
 693
 694struct platform_device *smu_get_ofdev(void)
 695{
 696        if (!smu)
 697                return NULL;
 698        return smu->of_dev;
 699}
 700
 701EXPORT_SYMBOL_GPL(smu_get_ofdev);
 702
 703/*
 704 * i2c interface
 705 */
 706
 707static 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
 757static void smu_i2c_retry(struct timer_list *unused)
 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
 770static 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(NULL);
 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
 824int 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                /* fall through */
 856        case SMU_I2C_TRANSFER_STDSUB:
 857                if (cmd->info.sublen > 3)
 858                        return -EINVAL;
 859                break;
 860        default:
 861                return -EINVAL;
 862        }
 863
 864        /* Finish setting up command based on transfer direction
 865         */
 866        if (cmd->read) {
 867                if (cmd->info.datalen > SMU_I2C_READ_MAX)
 868                        return -EINVAL;
 869                memset(cmd->info.data, 0xff, cmd->info.datalen);
 870                cmd->scmd.data_len = 9;
 871        } else {
 872                if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 873                        return -EINVAL;
 874                cmd->scmd.data_len = 9 + cmd->info.datalen;
 875        }
 876
 877        DPRINTK("SMU: i2c enqueuing command\n");
 878        DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 879                cmd->read ? "read" : "write", cmd->info.datalen,
 880                cmd->info.bus, cmd->info.caddr,
 881                cmd->info.subaddr[0], cmd->info.type);
 882
 883
 884        /* Enqueue command in i2c list, and if empty, enqueue also in
 885         * main command list
 886         */
 887        spin_lock_irqsave(&smu->lock, flags);
 888        if (smu->cmd_i2c_cur == NULL) {
 889                smu->cmd_i2c_cur = cmd;
 890                list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 891                if (smu->cmd_cur == NULL)
 892                        smu_start_cmd();
 893        } else
 894                list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 895        spin_unlock_irqrestore(&smu->lock, flags);
 896
 897        return 0;
 898}
 899
 900/*
 901 * Handling of "partitions"
 902 */
 903
 904static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 905{
 906        DECLARE_COMPLETION_ONSTACK(comp);
 907        unsigned int chunk;
 908        struct smu_cmd cmd;
 909        int rc;
 910        u8 params[8];
 911
 912        /* We currently use a chunk size of 0xe. We could check the
 913         * SMU firmware version and use bigger sizes though
 914         */
 915        chunk = 0xe;
 916
 917        while (len) {
 918                unsigned int clen = min(len, chunk);
 919
 920                cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 921                cmd.data_len = 7;
 922                cmd.data_buf = params;
 923                cmd.reply_len = chunk;
 924                cmd.reply_buf = dest;
 925                cmd.done = smu_done_complete;
 926                cmd.misc = &comp;
 927                params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 928                params[1] = 0x4;
 929                *((u32 *)&params[2]) = addr;
 930                params[6] = clen;
 931
 932                rc = smu_queue_cmd(&cmd);
 933                if (rc)
 934                        return rc;
 935                wait_for_completion(&comp);
 936                if (cmd.status != 0)
 937                        return rc;
 938                if (cmd.reply_len != clen) {
 939                        printk(KERN_DEBUG "SMU: short read in "
 940                               "smu_read_datablock, got: %d, want: %d\n",
 941                               cmd.reply_len, clen);
 942                        return -EIO;
 943                }
 944                len -= clen;
 945                addr += clen;
 946                dest += clen;
 947        }
 948        return 0;
 949}
 950
 951static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 952{
 953        DECLARE_COMPLETION_ONSTACK(comp);
 954        struct smu_simple_cmd cmd;
 955        unsigned int addr, len, tlen;
 956        struct smu_sdbp_header *hdr;
 957        struct property *prop;
 958
 959        /* First query the partition info */
 960        DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 961        smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 962                         smu_done_complete, &comp,
 963                         SMU_CMD_PARTITION_LATEST, id);
 964        wait_for_completion(&comp);
 965        DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 966                cmd.cmd.status, cmd.cmd.reply_len);
 967
 968        /* Partition doesn't exist (or other error) */
 969        if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 970                return NULL;
 971
 972        /* Fetch address and length from reply */
 973        addr = *((u16 *)cmd.buffer);
 974        len = cmd.buffer[3] << 2;
 975        /* Calucluate total length to allocate, including the 17 bytes
 976         * for "sdb-partition-XX" that we append at the end of the buffer
 977         */
 978        tlen = sizeof(struct property) + len + 18;
 979
 980        prop = kzalloc(tlen, GFP_KERNEL);
 981        if (prop == NULL)
 982                return NULL;
 983        hdr = (struct smu_sdbp_header *)(prop + 1);
 984        prop->name = ((char *)prop) + tlen - 18;
 985        sprintf(prop->name, "sdb-partition-%02x", id);
 986        prop->length = len;
 987        prop->value = hdr;
 988        prop->next = NULL;
 989
 990        /* Read the datablock */
 991        if (smu_read_datablock((u8 *)hdr, addr, len)) {
 992                printk(KERN_DEBUG "SMU: datablock read failed while reading "
 993                       "partition %02x !\n", id);
 994                goto failure;
 995        }
 996
 997        /* Got it, check a few things and create the property */
 998        if (hdr->id != id) {
 999                printk(KERN_DEBUG "SMU: Reading partition %02x and got "
1000                       "%02x !\n", id, hdr->id);
1001                goto failure;
1002        }
1003        if (of_add_property(smu->of_node, prop)) {
1004                printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1005                       "property !\n", id);
1006                goto failure;
1007        }
1008
1009        return hdr;
1010 failure:
1011        kfree(prop);
1012        return NULL;
1013}
1014
1015/* Note: Only allowed to return error code in pointers (using ERR_PTR)
1016 * when interruptible is 1
1017 */
1018const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1019                unsigned int *size, int interruptible)
1020{
1021        char pname[32];
1022        const struct smu_sdbp_header *part;
1023
1024        if (!smu)
1025                return NULL;
1026
1027        sprintf(pname, "sdb-partition-%02x", id);
1028
1029        DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1030
1031        if (interruptible) {
1032                int rc;
1033                rc = mutex_lock_interruptible(&smu_part_access);
1034                if (rc)
1035                        return ERR_PTR(rc);
1036        } else
1037                mutex_lock(&smu_part_access);
1038
1039        part = of_get_property(smu->of_node, pname, size);
1040        if (part == NULL) {
1041                DPRINTK("trying to extract from SMU ...\n");
1042                part = smu_create_sdb_partition(id);
1043                if (part != NULL && size)
1044                        *size = part->len << 2;
1045        }
1046        mutex_unlock(&smu_part_access);
1047        return part;
1048}
1049
1050const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1051{
1052        return __smu_get_sdb_partition(id, size, 0);
1053}
1054EXPORT_SYMBOL(smu_get_sdb_partition);
1055
1056
1057/*
1058 * Userland driver interface
1059 */
1060
1061
1062static LIST_HEAD(smu_clist);
1063static DEFINE_SPINLOCK(smu_clist_lock);
1064
1065enum smu_file_mode {
1066        smu_file_commands,
1067        smu_file_events,
1068        smu_file_closing
1069};
1070
1071struct smu_private
1072{
1073        struct list_head        list;
1074        enum smu_file_mode      mode;
1075        int                     busy;
1076        struct smu_cmd          cmd;
1077        spinlock_t              lock;
1078        wait_queue_head_t       wait;
1079        u8                      buffer[SMU_MAX_DATA];
1080};
1081
1082
1083static int smu_open(struct inode *inode, struct file *file)
1084{
1085        struct smu_private *pp;
1086        unsigned long flags;
1087
1088        pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1089        if (pp == 0)
1090                return -ENOMEM;
1091        spin_lock_init(&pp->lock);
1092        pp->mode = smu_file_commands;
1093        init_waitqueue_head(&pp->wait);
1094
1095        mutex_lock(&smu_mutex);
1096        spin_lock_irqsave(&smu_clist_lock, flags);
1097        list_add(&pp->list, &smu_clist);
1098        spin_unlock_irqrestore(&smu_clist_lock, flags);
1099        file->private_data = pp;
1100        mutex_unlock(&smu_mutex);
1101
1102        return 0;
1103}
1104
1105
1106static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1107{
1108        struct smu_private *pp = misc;
1109
1110        wake_up_all(&pp->wait);
1111}
1112
1113
1114static ssize_t smu_write(struct file *file, const char __user *buf,
1115                         size_t count, loff_t *ppos)
1116{
1117        struct smu_private *pp = file->private_data;
1118        unsigned long flags;
1119        struct smu_user_cmd_hdr hdr;
1120        int rc = 0;
1121
1122        if (pp->busy)
1123                return -EBUSY;
1124        else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1125                return -EFAULT;
1126        else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1127                pp->mode = smu_file_events;
1128                return 0;
1129        } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1130                const struct smu_sdbp_header *part;
1131                part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1132                if (part == NULL)
1133                        return -EINVAL;
1134                else if (IS_ERR(part))
1135                        return PTR_ERR(part);
1136                return 0;
1137        } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1138                return -EINVAL;
1139        else if (pp->mode != smu_file_commands)
1140                return -EBADFD;
1141        else if (hdr.data_len > SMU_MAX_DATA)
1142                return -EINVAL;
1143
1144        spin_lock_irqsave(&pp->lock, flags);
1145        if (pp->busy) {
1146                spin_unlock_irqrestore(&pp->lock, flags);
1147                return -EBUSY;
1148        }
1149        pp->busy = 1;
1150        pp->cmd.status = 1;
1151        spin_unlock_irqrestore(&pp->lock, flags);
1152
1153        if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1154                pp->busy = 0;
1155                return -EFAULT;
1156        }
1157
1158        pp->cmd.cmd = hdr.cmd;
1159        pp->cmd.data_len = hdr.data_len;
1160        pp->cmd.reply_len = SMU_MAX_DATA;
1161        pp->cmd.data_buf = pp->buffer;
1162        pp->cmd.reply_buf = pp->buffer;
1163        pp->cmd.done = smu_user_cmd_done;
1164        pp->cmd.misc = pp;
1165        rc = smu_queue_cmd(&pp->cmd);
1166        if (rc < 0)
1167                return rc;
1168        return count;
1169}
1170
1171
1172static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1173                                char __user *buf, size_t count)
1174{
1175        DECLARE_WAITQUEUE(wait, current);
1176        struct smu_user_reply_hdr hdr;
1177        unsigned long flags;
1178        int size, rc = 0;
1179
1180        if (!pp->busy)
1181                return 0;
1182        if (count < sizeof(struct smu_user_reply_hdr))
1183                return -EOVERFLOW;
1184        spin_lock_irqsave(&pp->lock, flags);
1185        if (pp->cmd.status == 1) {
1186                if (file->f_flags & O_NONBLOCK) {
1187                        spin_unlock_irqrestore(&pp->lock, flags);
1188                        return -EAGAIN;
1189                }
1190                add_wait_queue(&pp->wait, &wait);
1191                for (;;) {
1192                        set_current_state(TASK_INTERRUPTIBLE);
1193                        rc = 0;
1194                        if (pp->cmd.status != 1)
1195                                break;
1196                        rc = -ERESTARTSYS;
1197                        if (signal_pending(current))
1198                                break;
1199                        spin_unlock_irqrestore(&pp->lock, flags);
1200                        schedule();
1201                        spin_lock_irqsave(&pp->lock, flags);
1202                }
1203                set_current_state(TASK_RUNNING);
1204                remove_wait_queue(&pp->wait, &wait);
1205        }
1206        spin_unlock_irqrestore(&pp->lock, flags);
1207        if (rc)
1208                return rc;
1209        if (pp->cmd.status != 0)
1210                pp->cmd.reply_len = 0;
1211        size = sizeof(hdr) + pp->cmd.reply_len;
1212        if (count < size)
1213                size = count;
1214        rc = size;
1215        hdr.status = pp->cmd.status;
1216        hdr.reply_len = pp->cmd.reply_len;
1217        if (copy_to_user(buf, &hdr, sizeof(hdr)))
1218                return -EFAULT;
1219        size -= sizeof(hdr);
1220        if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1221                return -EFAULT;
1222        pp->busy = 0;
1223
1224        return rc;
1225}
1226
1227
1228static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1229                               char __user *buf, size_t count)
1230{
1231        /* Not implemented */
1232        msleep_interruptible(1000);
1233        return 0;
1234}
1235
1236
1237static ssize_t smu_read(struct file *file, char __user *buf,
1238                        size_t count, loff_t *ppos)
1239{
1240        struct smu_private *pp = file->private_data;
1241
1242        if (pp->mode == smu_file_commands)
1243                return smu_read_command(file, pp, buf, count);
1244        if (pp->mode == smu_file_events)
1245                return smu_read_events(file, pp, buf, count);
1246
1247        return -EBADFD;
1248}
1249
1250static __poll_t smu_fpoll(struct file *file, poll_table *wait)
1251{
1252        struct smu_private *pp = file->private_data;
1253        __poll_t mask = 0;
1254        unsigned long flags;
1255
1256        if (pp == 0)
1257                return 0;
1258
1259        if (pp->mode == smu_file_commands) {
1260                poll_wait(file, &pp->wait, wait);
1261
1262                spin_lock_irqsave(&pp->lock, flags);
1263                if (pp->busy && pp->cmd.status != 1)
1264                        mask |= EPOLLIN;
1265                spin_unlock_irqrestore(&pp->lock, flags);
1266        }
1267        if (pp->mode == smu_file_events) {
1268                /* Not yet implemented */
1269        }
1270        return mask;
1271}
1272
1273static int smu_release(struct inode *inode, struct file *file)
1274{
1275        struct smu_private *pp = file->private_data;
1276        unsigned long flags;
1277        unsigned int busy;
1278
1279        if (pp == 0)
1280                return 0;
1281
1282        file->private_data = NULL;
1283
1284        /* Mark file as closing to avoid races with new request */
1285        spin_lock_irqsave(&pp->lock, flags);
1286        pp->mode = smu_file_closing;
1287        busy = pp->busy;
1288
1289        /* Wait for any pending request to complete */
1290        if (busy && pp->cmd.status == 1) {
1291                DECLARE_WAITQUEUE(wait, current);
1292
1293                add_wait_queue(&pp->wait, &wait);
1294                for (;;) {
1295                        set_current_state(TASK_UNINTERRUPTIBLE);
1296                        if (pp->cmd.status != 1)
1297                                break;
1298                        spin_unlock_irqrestore(&pp->lock, flags);
1299                        schedule();
1300                        spin_lock_irqsave(&pp->lock, flags);
1301                }
1302                set_current_state(TASK_RUNNING);
1303                remove_wait_queue(&pp->wait, &wait);
1304        }
1305        spin_unlock_irqrestore(&pp->lock, flags);
1306
1307        spin_lock_irqsave(&smu_clist_lock, flags);
1308        list_del(&pp->list);
1309        spin_unlock_irqrestore(&smu_clist_lock, flags);
1310        kfree(pp);
1311
1312        return 0;
1313}
1314
1315
1316static const struct file_operations smu_device_fops = {
1317        .llseek         = no_llseek,
1318        .read           = smu_read,
1319        .write          = smu_write,
1320        .poll           = smu_fpoll,
1321        .open           = smu_open,
1322        .release        = smu_release,
1323};
1324
1325static struct miscdevice pmu_device = {
1326        MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1327};
1328
1329static int smu_device_init(void)
1330{
1331        if (!smu)
1332                return -ENODEV;
1333        if (misc_register(&pmu_device) < 0)
1334                printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1335        return 0;
1336}
1337device_initcall(smu_device_init);
1338