linux/drivers/macintosh/smu.c
<<
>>
Prefs
   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: %8ph\n", cmd->data_buf);
 124
 125        /* Fill the SMU command buffer */
 126        smu->cmd_buf->cmd = cmd->cmd;
 127        smu->cmd_buf->length = cmd->data_len;
 128        memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 129
 130        /* Flush command and data to RAM */
 131        faddr = (unsigned long)smu->cmd_buf;
 132        fend = faddr + smu->cmd_buf->length + 2;
 133        flush_inval_dcache_range(faddr, fend);
 134
 135
 136        /* We also disable NAP mode for the duration of the command
 137         * on U3 based machines.
 138         * This is slightly racy as it can be written back to 1 by a sysctl
 139         * but that never happens in practice. There seem to be an issue with
 140         * U3 based machines such as the iMac G5 where napping for the
 141         * whole duration of the command prevents the SMU from fetching it
 142         * from memory. This might be related to the strange i2c based
 143         * mechanism the SMU uses to access memory.
 144         */
 145        if (smu->broken_nap)
 146                powersave_nap = 0;
 147
 148        /* This isn't exactly a DMA mapping here, I suspect
 149         * the SMU is actually communicating with us via i2c to the
 150         * northbridge or the CPU to access RAM.
 151         */
 152        writel(smu->cmd_buf_abs, smu->db_buf);
 153
 154        /* Ring the SMU doorbell */
 155        pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 156}
 157
 158
 159static irqreturn_t smu_db_intr(int irq, void *arg)
 160{
 161        unsigned long flags;
 162        struct smu_cmd *cmd;
 163        void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 164        void *misc = NULL;
 165        u8 gpio;
 166        int rc = 0;
 167
 168        /* SMU completed the command, well, we hope, let's make sure
 169         * of it
 170         */
 171        spin_lock_irqsave(&smu->lock, flags);
 172
 173        gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 174        if ((gpio & 7) != 7) {
 175                spin_unlock_irqrestore(&smu->lock, flags);
 176                return IRQ_HANDLED;
 177        }
 178
 179        cmd = smu->cmd_cur;
 180        smu->cmd_cur = NULL;
 181        if (cmd == NULL)
 182                goto bail;
 183
 184        if (rc == 0) {
 185                unsigned long faddr;
 186                int reply_len;
 187                u8 ack;
 188
 189                /* CPU might have brought back the cache line, so we need
 190                 * to flush again before peeking at the SMU response. We
 191                 * flush the entire buffer for now as we haven't read the
 192                 * reply length (it's only 2 cache lines anyway)
 193                 */
 194                faddr = (unsigned long)smu->cmd_buf;
 195                flush_inval_dcache_range(faddr, faddr + 256);
 196
 197                /* Now check ack */
 198                ack = (~cmd->cmd) & 0xff;
 199                if (ack != smu->cmd_buf->cmd) {
 200                        DPRINTK("SMU: incorrect ack, want %x got %x\n",
 201                                ack, smu->cmd_buf->cmd);
 202                        rc = -EIO;
 203                }
 204                reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 205                DPRINTK("SMU: reply len: %d\n", reply_len);
 206                if (reply_len > cmd->reply_len) {
 207                        printk(KERN_WARNING "SMU: reply buffer too small,"
 208                               "got %d bytes for a %d bytes buffer\n",
 209                               reply_len, cmd->reply_len);
 210                        reply_len = cmd->reply_len;
 211                }
 212                cmd->reply_len = reply_len;
 213                if (cmd->reply_buf && reply_len)
 214                        memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 215        }
 216
 217        /* Now complete the command. Write status last in order as we lost
 218         * ownership of the command structure as soon as it's no longer -1
 219         */
 220        done = cmd->done;
 221        misc = cmd->misc;
 222        mb();
 223        cmd->status = rc;
 224
 225        /* Re-enable NAP mode */
 226        if (smu->broken_nap)
 227                powersave_nap = 1;
 228 bail:
 229        /* Start next command if any */
 230        smu_start_cmd();
 231        spin_unlock_irqrestore(&smu->lock, flags);
 232
 233        /* Call command completion handler if any */
 234        if (done)
 235                done(cmd, misc);
 236
 237        /* It's an edge interrupt, nothing to do */
 238        return IRQ_HANDLED;
 239}
 240
 241
 242static irqreturn_t smu_msg_intr(int irq, void *arg)
 243{
 244        /* I don't quite know what to do with this one, we seem to never
 245         * receive it, so I suspect we have to arm it someway in the SMU
 246         * to start getting events that way.
 247         */
 248
 249        printk(KERN_INFO "SMU: message interrupt !\n");
 250
 251        /* It's an edge interrupt, nothing to do */
 252        return IRQ_HANDLED;
 253}
 254
 255
 256/*
 257 * Queued command management.
 258 *
 259 */
 260
 261int smu_queue_cmd(struct smu_cmd *cmd)
 262{
 263        unsigned long flags;
 264
 265        if (smu == NULL)
 266                return -ENODEV;
 267        if (cmd->data_len > SMU_MAX_DATA ||
 268            cmd->reply_len > SMU_MAX_DATA)
 269                return -EINVAL;
 270
 271        cmd->status = 1;
 272        spin_lock_irqsave(&smu->lock, flags);
 273        list_add_tail(&cmd->link, &smu->cmd_list);
 274        if (smu->cmd_cur == NULL)
 275                smu_start_cmd();
 276        spin_unlock_irqrestore(&smu->lock, flags);
 277
 278        /* Workaround for early calls when irq isn't available */
 279        if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 280                smu_spinwait_cmd(cmd);
 281
 282        return 0;
 283}
 284EXPORT_SYMBOL(smu_queue_cmd);
 285
 286
 287int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 288                     unsigned int data_len,
 289                     void (*done)(struct smu_cmd *cmd, void *misc),
 290                     void *misc, ...)
 291{
 292        struct smu_cmd *cmd = &scmd->cmd;
 293        va_list list;
 294        int i;
 295
 296        if (data_len > sizeof(scmd->buffer))
 297                return -EINVAL;
 298
 299        memset(scmd, 0, sizeof(*scmd));
 300        cmd->cmd = command;
 301        cmd->data_len = data_len;
 302        cmd->data_buf = scmd->buffer;
 303        cmd->reply_len = sizeof(scmd->buffer);
 304        cmd->reply_buf = scmd->buffer;
 305        cmd->done = done;
 306        cmd->misc = misc;
 307
 308        va_start(list, misc);
 309        for (i = 0; i < data_len; ++i)
 310                scmd->buffer[i] = (u8)va_arg(list, int);
 311        va_end(list);
 312
 313        return smu_queue_cmd(cmd);
 314}
 315EXPORT_SYMBOL(smu_queue_simple);
 316
 317
 318void smu_poll(void)
 319{
 320        u8 gpio;
 321
 322        if (smu == NULL)
 323                return;
 324
 325        gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 326        if ((gpio & 7) == 7)
 327                smu_db_intr(smu->db_irq, smu);
 328}
 329EXPORT_SYMBOL(smu_poll);
 330
 331
 332void smu_done_complete(struct smu_cmd *cmd, void *misc)
 333{
 334        struct completion *comp = misc;
 335
 336        complete(comp);
 337}
 338EXPORT_SYMBOL(smu_done_complete);
 339
 340
 341void smu_spinwait_cmd(struct smu_cmd *cmd)
 342{
 343        while(cmd->status == 1)
 344                smu_poll();
 345}
 346EXPORT_SYMBOL(smu_spinwait_cmd);
 347
 348
 349/* RTC low level commands */
 350static inline int bcd2hex (int n)
 351{
 352        return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 353}
 354
 355
 356static inline int hex2bcd (int n)
 357{
 358        return ((n / 10) << 4) + (n % 10);
 359}
 360
 361
 362static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 363                                        struct rtc_time *time)
 364{
 365        cmd_buf->cmd = 0x8e;
 366        cmd_buf->length = 8;
 367        cmd_buf->data[0] = 0x80;
 368        cmd_buf->data[1] = hex2bcd(time->tm_sec);
 369        cmd_buf->data[2] = hex2bcd(time->tm_min);
 370        cmd_buf->data[3] = hex2bcd(time->tm_hour);
 371        cmd_buf->data[4] = time->tm_wday;
 372        cmd_buf->data[5] = hex2bcd(time->tm_mday);
 373        cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 374        cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 375}
 376
 377
 378int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 379{
 380        struct smu_simple_cmd cmd;
 381        int rc;
 382
 383        if (smu == NULL)
 384                return -ENODEV;
 385
 386        memset(time, 0, sizeof(struct rtc_time));
 387        rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 388                              SMU_CMD_RTC_GET_DATETIME);
 389        if (rc)
 390                return rc;
 391        smu_spinwait_simple(&cmd);
 392
 393        time->tm_sec = bcd2hex(cmd.buffer[0]);
 394        time->tm_min = bcd2hex(cmd.buffer[1]);
 395        time->tm_hour = bcd2hex(cmd.buffer[2]);
 396        time->tm_wday = bcd2hex(cmd.buffer[3]);
 397        time->tm_mday = bcd2hex(cmd.buffer[4]);
 398        time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 399        time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 400
 401        return 0;
 402}
 403
 404
 405int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 406{
 407        struct smu_simple_cmd cmd;
 408        int rc;
 409
 410        if (smu == NULL)
 411                return -ENODEV;
 412
 413        rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 414                              SMU_CMD_RTC_SET_DATETIME,
 415                              hex2bcd(time->tm_sec),
 416                              hex2bcd(time->tm_min),
 417                              hex2bcd(time->tm_hour),
 418                              time->tm_wday,
 419                              hex2bcd(time->tm_mday),
 420                              hex2bcd(time->tm_mon) + 1,
 421                              hex2bcd(time->tm_year - 100));
 422        if (rc)
 423                return rc;
 424        smu_spinwait_simple(&cmd);
 425
 426        return 0;
 427}
 428
 429
 430void smu_shutdown(void)
 431{
 432        struct smu_simple_cmd cmd;
 433
 434        if (smu == NULL)
 435                return;
 436
 437        if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 438                             'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 439                return;
 440        smu_spinwait_simple(&cmd);
 441        for (;;)
 442                ;
 443}
 444
 445
 446void smu_restart(void)
 447{
 448        struct smu_simple_cmd cmd;
 449
 450        if (smu == NULL)
 451                return;
 452
 453        if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 454                             'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 455                return;
 456        smu_spinwait_simple(&cmd);
 457        for (;;)
 458                ;
 459}
 460
 461
 462int smu_present(void)
 463{
 464        return smu != NULL;
 465}
 466EXPORT_SYMBOL(smu_present);
 467
 468
 469int __init smu_init (void)
 470{
 471        struct device_node *np;
 472        const u32 *data;
 473        int ret = 0;
 474
 475        np = of_find_node_by_type(NULL, "smu");
 476        if (np == NULL)
 477                return -ENODEV;
 478
 479        printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 480
 481        if (smu_cmdbuf_abs == 0) {
 482                printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 483                ret = -EINVAL;
 484                goto fail_np;
 485        }
 486
 487        smu = alloc_bootmem(sizeof(struct smu_device));
 488
 489        spin_lock_init(&smu->lock);
 490        INIT_LIST_HEAD(&smu->cmd_list);
 491        INIT_LIST_HEAD(&smu->cmd_i2c_list);
 492        smu->of_node = np;
 493        smu->db_irq = NO_IRQ;
 494        smu->msg_irq = NO_IRQ;
 495
 496        /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 497         * 32 bits value safely
 498         */
 499        smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 500        smu->cmd_buf = __va(smu_cmdbuf_abs);
 501
 502        smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 503        if (smu->db_node == NULL) {
 504                printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 505                ret = -ENXIO;
 506                goto fail_bootmem;
 507        }
 508        data = of_get_property(smu->db_node, "reg", NULL);
 509        if (data == NULL) {
 510                printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 511                ret = -ENXIO;
 512                goto fail_db_node;
 513        }
 514
 515        /* Current setup has one doorbell GPIO that does both doorbell
 516         * and ack. GPIOs are at 0x50, best would be to find that out
 517         * in the device-tree though.
 518         */
 519        smu->doorbell = *data;
 520        if (smu->doorbell < 0x50)
 521                smu->doorbell += 0x50;
 522
 523        /* Now look for the smu-interrupt GPIO */
 524        do {
 525                smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 526                if (smu->msg_node == NULL)
 527                        break;
 528                data = of_get_property(smu->msg_node, "reg", NULL);
 529                if (data == NULL) {
 530                        of_node_put(smu->msg_node);
 531                        smu->msg_node = NULL;
 532                        break;
 533                }
 534                smu->msg = *data;
 535                if (smu->msg < 0x50)
 536                        smu->msg += 0x50;
 537        } while(0);
 538
 539        /* Doorbell buffer is currently hard-coded, I didn't find a proper
 540         * device-tree entry giving the address. Best would probably to use
 541         * an offset for K2 base though, but let's do it that way for now.
 542         */
 543        smu->db_buf = ioremap(0x8000860c, 0x1000);
 544        if (smu->db_buf == NULL) {
 545                printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 546                ret = -ENXIO;
 547                goto fail_msg_node;
 548        }
 549
 550        /* U3 has an issue with NAP mode when issuing SMU commands */
 551        smu->broken_nap = pmac_get_uninorth_variant() < 4;
 552        if (smu->broken_nap)
 553                printk(KERN_INFO "SMU: using NAP mode workaround\n");
 554
 555        sys_ctrler = SYS_CTRLER_SMU;
 556        return 0;
 557
 558fail_msg_node:
 559        if (smu->msg_node)
 560                of_node_put(smu->msg_node);
 561fail_db_node:
 562        of_node_put(smu->db_node);
 563fail_bootmem:
 564        free_bootmem(__pa(smu), sizeof(struct smu_device));
 565        smu = NULL;
 566fail_np:
 567        of_node_put(np);
 568        return ret;
 569}
 570
 571
 572static int smu_late_init(void)
 573{
 574        if (!smu)
 575                return 0;
 576
 577        init_timer(&smu->i2c_timer);
 578        smu->i2c_timer.function = smu_i2c_retry;
 579        smu->i2c_timer.data = (unsigned long)smu;
 580
 581        if (smu->db_node) {
 582                smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 583                if (smu->db_irq == NO_IRQ)
 584                        printk(KERN_ERR "smu: failed to map irq for node %s\n",
 585                               smu->db_node->full_name);
 586        }
 587        if (smu->msg_node) {
 588                smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 589                if (smu->msg_irq == NO_IRQ)
 590                        printk(KERN_ERR "smu: failed to map irq for node %s\n",
 591                               smu->msg_node->full_name);
 592        }
 593
 594        /*
 595         * Try to request the interrupts
 596         */
 597
 598        if (smu->db_irq != NO_IRQ) {
 599                if (request_irq(smu->db_irq, smu_db_intr,
 600                                IRQF_SHARED, "SMU doorbell", smu) < 0) {
 601                        printk(KERN_WARNING "SMU: can't "
 602                               "request interrupt %d\n",
 603                               smu->db_irq);
 604                        smu->db_irq = NO_IRQ;
 605                }
 606        }
 607
 608        if (smu->msg_irq != NO_IRQ) {
 609                if (request_irq(smu->msg_irq, smu_msg_intr,
 610                                IRQF_SHARED, "SMU message", smu) < 0) {
 611                        printk(KERN_WARNING "SMU: can't "
 612                               "request interrupt %d\n",
 613                               smu->msg_irq);
 614                        smu->msg_irq = NO_IRQ;
 615                }
 616        }
 617
 618        smu_irq_inited = 1;
 619        return 0;
 620}
 621/* This has to be before arch_initcall as the low i2c stuff relies on the
 622 * above having been done before we reach arch_initcalls
 623 */
 624core_initcall(smu_late_init);
 625
 626/*
 627 * sysfs visibility
 628 */
 629
 630static void smu_expose_childs(struct work_struct *unused)
 631{
 632        struct device_node *np;
 633
 634        for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 635                if (of_device_is_compatible(np, "smu-sensors"))
 636                        of_platform_device_create(np, "smu-sensors",
 637                                                  &smu->of_dev->dev);
 638}
 639
 640static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 641
 642static int smu_platform_probe(struct platform_device* dev)
 643{
 644        if (!smu)
 645                return -ENODEV;
 646        smu->of_dev = dev;
 647
 648        /*
 649         * Ok, we are matched, now expose all i2c busses. We have to defer
 650         * that unfortunately or it would deadlock inside the device model
 651         */
 652        schedule_work(&smu_expose_childs_work);
 653
 654        return 0;
 655}
 656
 657static const struct of_device_id smu_platform_match[] =
 658{
 659        {
 660                .type           = "smu",
 661        },
 662        {},
 663};
 664
 665static struct platform_driver smu_of_platform_driver =
 666{
 667        .driver = {
 668                .name = "smu",
 669                .owner = THIS_MODULE,
 670                .of_match_table = smu_platform_match,
 671        },
 672        .probe          = smu_platform_probe,
 673};
 674
 675static int __init smu_init_sysfs(void)
 676{
 677        /*
 678         * For now, we don't power manage machines with an SMU chip,
 679         * I'm a bit too far from figuring out how that works with those
 680         * new chipsets, but that will come back and bite us
 681         */
 682        platform_driver_register(&smu_of_platform_driver);
 683        return 0;
 684}
 685
 686device_initcall(smu_init_sysfs);
 687
 688struct platform_device *smu_get_ofdev(void)
 689{
 690        if (!smu)
 691                return NULL;
 692        return smu->of_dev;
 693}
 694
 695EXPORT_SYMBOL_GPL(smu_get_ofdev);
 696
 697/*
 698 * i2c interface
 699 */
 700
 701static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 702{
 703        void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 704        void *misc = cmd->misc;
 705        unsigned long flags;
 706
 707        /* Check for read case */
 708        if (!fail && cmd->read) {
 709                if (cmd->pdata[0] < 1)
 710                        fail = 1;
 711                else
 712                        memcpy(cmd->info.data, &cmd->pdata[1],
 713                               cmd->info.datalen);
 714        }
 715
 716        DPRINTK("SMU: completing, success: %d\n", !fail);
 717
 718        /* Update status and mark no pending i2c command with lock
 719         * held so nobody comes in while we dequeue an eventual
 720         * pending next i2c command
 721         */
 722        spin_lock_irqsave(&smu->lock, flags);
 723        smu->cmd_i2c_cur = NULL;
 724        wmb();
 725        cmd->status = fail ? -EIO : 0;
 726
 727        /* Is there another i2c command waiting ? */
 728        if (!list_empty(&smu->cmd_i2c_list)) {
 729                struct smu_i2c_cmd *newcmd;
 730
 731                /* Fetch it, new current, remove from list */
 732                newcmd = list_entry(smu->cmd_i2c_list.next,
 733                                    struct smu_i2c_cmd, link);
 734                smu->cmd_i2c_cur = newcmd;
 735                list_del(&cmd->link);
 736
 737                /* Queue with low level smu */
 738                list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 739                if (smu->cmd_cur == NULL)
 740                        smu_start_cmd();
 741        }
 742        spin_unlock_irqrestore(&smu->lock, flags);
 743
 744        /* Call command completion handler if any */
 745        if (done)
 746                done(cmd, misc);
 747
 748}
 749
 750
 751static void smu_i2c_retry(unsigned long data)
 752{
 753        struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 754
 755        DPRINTK("SMU: i2c failure, requeuing...\n");
 756
 757        /* requeue command simply by resetting reply_len */
 758        cmd->pdata[0] = 0xff;
 759        cmd->scmd.reply_len = sizeof(cmd->pdata);
 760        smu_queue_cmd(&cmd->scmd);
 761}
 762
 763
 764static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 765{
 766        struct smu_i2c_cmd      *cmd = misc;
 767        int                     fail = 0;
 768
 769        DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 770                cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 771
 772        /* Check for possible status */
 773        if (scmd->status < 0)
 774                fail = 1;
 775        else if (cmd->read) {
 776                if (cmd->stage == 0)
 777                        fail = cmd->pdata[0] != 0;
 778                else
 779                        fail = cmd->pdata[0] >= 0x80;
 780        } else {
 781                fail = cmd->pdata[0] != 0;
 782        }
 783
 784        /* Handle failures by requeuing command, after 5ms interval
 785         */
 786        if (fail && --cmd->retries > 0) {
 787                DPRINTK("SMU: i2c failure, starting timer...\n");
 788                BUG_ON(cmd != smu->cmd_i2c_cur);
 789                if (!smu_irq_inited) {
 790                        mdelay(5);
 791                        smu_i2c_retry(0);
 792                        return;
 793                }
 794                mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 795                return;
 796        }
 797
 798        /* If failure or stage 1, command is complete */
 799        if (fail || cmd->stage != 0) {
 800                smu_i2c_complete_command(cmd, fail);
 801                return;
 802        }
 803
 804        DPRINTK("SMU: going to stage 1\n");
 805
 806        /* Ok, initial command complete, now poll status */
 807        scmd->reply_buf = cmd->pdata;
 808        scmd->reply_len = sizeof(cmd->pdata);
 809        scmd->data_buf = cmd->pdata;
 810        scmd->data_len = 1;
 811        cmd->pdata[0] = 0;
 812        cmd->stage = 1;
 813        cmd->retries = 20;
 814        smu_queue_cmd(scmd);
 815}
 816
 817
 818int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 819{
 820        unsigned long flags;
 821
 822        if (smu == NULL)
 823                return -ENODEV;
 824
 825        /* Fill most fields of scmd */
 826        cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 827        cmd->scmd.done = smu_i2c_low_completion;
 828        cmd->scmd.misc = cmd;
 829        cmd->scmd.reply_buf = cmd->pdata;
 830        cmd->scmd.reply_len = sizeof(cmd->pdata);
 831        cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 832        cmd->scmd.status = 1;
 833        cmd->stage = 0;
 834        cmd->pdata[0] = 0xff;
 835        cmd->retries = 20;
 836        cmd->status = 1;
 837
 838        /* Check transfer type, sanitize some "info" fields
 839         * based on transfer type and do more checking
 840         */
 841        cmd->info.caddr = cmd->info.devaddr;
 842        cmd->read = cmd->info.devaddr & 0x01;
 843        switch(cmd->info.type) {
 844        case SMU_I2C_TRANSFER_SIMPLE:
 845                memset(&cmd->info.sublen, 0, 4);
 846                break;
 847        case SMU_I2C_TRANSFER_COMBINED:
 848                cmd->info.devaddr &= 0xfe;
 849        case SMU_I2C_TRANSFER_STDSUB:
 850                if (cmd->info.sublen > 3)
 851                        return -EINVAL;
 852                break;
 853        default:
 854                return -EINVAL;
 855        }
 856
 857        /* Finish setting up command based on transfer direction
 858         */
 859        if (cmd->read) {
 860                if (cmd->info.datalen > SMU_I2C_READ_MAX)
 861                        return -EINVAL;
 862                memset(cmd->info.data, 0xff, cmd->info.datalen);
 863                cmd->scmd.data_len = 9;
 864        } else {
 865                if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 866                        return -EINVAL;
 867                cmd->scmd.data_len = 9 + cmd->info.datalen;
 868        }
 869
 870        DPRINTK("SMU: i2c enqueuing command\n");
 871        DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 872                cmd->read ? "read" : "write", cmd->info.datalen,
 873                cmd->info.bus, cmd->info.caddr,
 874                cmd->info.subaddr[0], cmd->info.type);
 875
 876
 877        /* Enqueue command in i2c list, and if empty, enqueue also in
 878         * main command list
 879         */
 880        spin_lock_irqsave(&smu->lock, flags);
 881        if (smu->cmd_i2c_cur == NULL) {
 882                smu->cmd_i2c_cur = cmd;
 883                list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 884                if (smu->cmd_cur == NULL)
 885                        smu_start_cmd();
 886        } else
 887                list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 888        spin_unlock_irqrestore(&smu->lock, flags);
 889
 890        return 0;
 891}
 892
 893/*
 894 * Handling of "partitions"
 895 */
 896
 897static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 898{
 899        DECLARE_COMPLETION_ONSTACK(comp);
 900        unsigned int chunk;
 901        struct smu_cmd cmd;
 902        int rc;
 903        u8 params[8];
 904
 905        /* We currently use a chunk size of 0xe. We could check the
 906         * SMU firmware version and use bigger sizes though
 907         */
 908        chunk = 0xe;
 909
 910        while (len) {
 911                unsigned int clen = min(len, chunk);
 912
 913                cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 914                cmd.data_len = 7;
 915                cmd.data_buf = params;
 916                cmd.reply_len = chunk;
 917                cmd.reply_buf = dest;
 918                cmd.done = smu_done_complete;
 919                cmd.misc = &comp;
 920                params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 921                params[1] = 0x4;
 922                *((u32 *)&params[2]) = addr;
 923                params[6] = clen;
 924
 925                rc = smu_queue_cmd(&cmd);
 926                if (rc)
 927                        return rc;
 928                wait_for_completion(&comp);
 929                if (cmd.status != 0)
 930                        return rc;
 931                if (cmd.reply_len != clen) {
 932                        printk(KERN_DEBUG "SMU: short read in "
 933                               "smu_read_datablock, got: %d, want: %d\n",
 934                               cmd.reply_len, clen);
 935                        return -EIO;
 936                }
 937                len -= clen;
 938                addr += clen;
 939                dest += clen;
 940        }
 941        return 0;
 942}
 943
 944static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 945{
 946        DECLARE_COMPLETION_ONSTACK(comp);
 947        struct smu_simple_cmd cmd;
 948        unsigned int addr, len, tlen;
 949        struct smu_sdbp_header *hdr;
 950        struct property *prop;
 951
 952        /* First query the partition info */
 953        DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 954        smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 955                         smu_done_complete, &comp,
 956                         SMU_CMD_PARTITION_LATEST, id);
 957        wait_for_completion(&comp);
 958        DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 959                cmd.cmd.status, cmd.cmd.reply_len);
 960
 961        /* Partition doesn't exist (or other error) */
 962        if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 963                return NULL;
 964
 965        /* Fetch address and length from reply */
 966        addr = *((u16 *)cmd.buffer);
 967        len = cmd.buffer[3] << 2;
 968        /* Calucluate total length to allocate, including the 17 bytes
 969         * for "sdb-partition-XX" that we append at the end of the buffer
 970         */
 971        tlen = sizeof(struct property) + len + 18;
 972
 973        prop = kzalloc(tlen, GFP_KERNEL);
 974        if (prop == NULL)
 975                return NULL;
 976        hdr = (struct smu_sdbp_header *)(prop + 1);
 977        prop->name = ((char *)prop) + tlen - 18;
 978        sprintf(prop->name, "sdb-partition-%02x", id);
 979        prop->length = len;
 980        prop->value = hdr;
 981        prop->next = NULL;
 982
 983        /* Read the datablock */
 984        if (smu_read_datablock((u8 *)hdr, addr, len)) {
 985                printk(KERN_DEBUG "SMU: datablock read failed while reading "
 986                       "partition %02x !\n", id);
 987                goto failure;
 988        }
 989
 990        /* Got it, check a few things and create the property */
 991        if (hdr->id != id) {
 992                printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 993                       "%02x !\n", id, hdr->id);
 994                goto failure;
 995        }
 996        if (of_add_property(smu->of_node, prop)) {
 997                printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
 998                       "property !\n", id);
 999                goto failure;
1000        }
1001
1002        return hdr;
1003 failure:
1004        kfree(prop);
1005        return NULL;
1006}
1007
1008/* Note: Only allowed to return error code in pointers (using ERR_PTR)
1009 * when interruptible is 1
1010 */
1011const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1012                unsigned int *size, int interruptible)
1013{
1014        char pname[32];
1015        const struct smu_sdbp_header *part;
1016
1017        if (!smu)
1018                return NULL;
1019
1020        sprintf(pname, "sdb-partition-%02x", id);
1021
1022        DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1023
1024        if (interruptible) {
1025                int rc;
1026                rc = mutex_lock_interruptible(&smu_part_access);
1027                if (rc)
1028                        return ERR_PTR(rc);
1029        } else
1030                mutex_lock(&smu_part_access);
1031
1032        part = of_get_property(smu->of_node, pname, size);
1033        if (part == NULL) {
1034                DPRINTK("trying to extract from SMU ...\n");
1035                part = smu_create_sdb_partition(id);
1036                if (part != NULL && size)
1037                        *size = part->len << 2;
1038        }
1039        mutex_unlock(&smu_part_access);
1040        return part;
1041}
1042
1043const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1044{
1045        return __smu_get_sdb_partition(id, size, 0);
1046}
1047EXPORT_SYMBOL(smu_get_sdb_partition);
1048
1049
1050/*
1051 * Userland driver interface
1052 */
1053
1054
1055static LIST_HEAD(smu_clist);
1056static DEFINE_SPINLOCK(smu_clist_lock);
1057
1058enum smu_file_mode {
1059        smu_file_commands,
1060        smu_file_events,
1061        smu_file_closing
1062};
1063
1064struct smu_private
1065{
1066        struct list_head        list;
1067        enum smu_file_mode      mode;
1068        int                     busy;
1069        struct smu_cmd          cmd;
1070        spinlock_t              lock;
1071        wait_queue_head_t       wait;
1072        u8                      buffer[SMU_MAX_DATA];
1073};
1074
1075
1076static int smu_open(struct inode *inode, struct file *file)
1077{
1078        struct smu_private *pp;
1079        unsigned long flags;
1080
1081        pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1082        if (pp == 0)
1083                return -ENOMEM;
1084        spin_lock_init(&pp->lock);
1085        pp->mode = smu_file_commands;
1086        init_waitqueue_head(&pp->wait);
1087
1088        mutex_lock(&smu_mutex);
1089        spin_lock_irqsave(&smu_clist_lock, flags);
1090        list_add(&pp->list, &smu_clist);
1091        spin_unlock_irqrestore(&smu_clist_lock, flags);
1092        file->private_data = pp;
1093        mutex_unlock(&smu_mutex);
1094
1095        return 0;
1096}
1097
1098
1099static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1100{
1101        struct smu_private *pp = misc;
1102
1103        wake_up_all(&pp->wait);
1104}
1105
1106
1107static ssize_t smu_write(struct file *file, const char __user *buf,
1108                         size_t count, loff_t *ppos)
1109{
1110        struct smu_private *pp = file->private_data;
1111        unsigned long flags;
1112        struct smu_user_cmd_hdr hdr;
1113        int rc = 0;
1114
1115        if (pp->busy)
1116                return -EBUSY;
1117        else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1118                return -EFAULT;
1119        else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1120                pp->mode = smu_file_events;
1121                return 0;
1122        } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1123                const struct smu_sdbp_header *part;
1124                part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1125                if (part == NULL)
1126                        return -EINVAL;
1127                else if (IS_ERR(part))
1128                        return PTR_ERR(part);
1129                return 0;
1130        } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1131                return -EINVAL;
1132        else if (pp->mode != smu_file_commands)
1133                return -EBADFD;
1134        else if (hdr.data_len > SMU_MAX_DATA)
1135                return -EINVAL;
1136
1137        spin_lock_irqsave(&pp->lock, flags);
1138        if (pp->busy) {
1139                spin_unlock_irqrestore(&pp->lock, flags);
1140                return -EBUSY;
1141        }
1142        pp->busy = 1;
1143        pp->cmd.status = 1;
1144        spin_unlock_irqrestore(&pp->lock, flags);
1145
1146        if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1147                pp->busy = 0;
1148                return -EFAULT;
1149        }
1150
1151        pp->cmd.cmd = hdr.cmd;
1152        pp->cmd.data_len = hdr.data_len;
1153        pp->cmd.reply_len = SMU_MAX_DATA;
1154        pp->cmd.data_buf = pp->buffer;
1155        pp->cmd.reply_buf = pp->buffer;
1156        pp->cmd.done = smu_user_cmd_done;
1157        pp->cmd.misc = pp;
1158        rc = smu_queue_cmd(&pp->cmd);
1159        if (rc < 0)
1160                return rc;
1161        return count;
1162}
1163
1164
1165static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1166                                char __user *buf, size_t count)
1167{
1168        DECLARE_WAITQUEUE(wait, current);
1169        struct smu_user_reply_hdr hdr;
1170        unsigned long flags;
1171        int size, rc = 0;
1172
1173        if (!pp->busy)
1174                return 0;
1175        if (count < sizeof(struct smu_user_reply_hdr))
1176                return -EOVERFLOW;
1177        spin_lock_irqsave(&pp->lock, flags);
1178        if (pp->cmd.status == 1) {
1179                if (file->f_flags & O_NONBLOCK) {
1180                        spin_unlock_irqrestore(&pp->lock, flags);
1181                        return -EAGAIN;
1182                }
1183                add_wait_queue(&pp->wait, &wait);
1184                for (;;) {
1185                        set_current_state(TASK_INTERRUPTIBLE);
1186                        rc = 0;
1187                        if (pp->cmd.status != 1)
1188                                break;
1189                        rc = -ERESTARTSYS;
1190                        if (signal_pending(current))
1191                                break;
1192                        spin_unlock_irqrestore(&pp->lock, flags);
1193                        schedule();
1194                        spin_lock_irqsave(&pp->lock, flags);
1195                }
1196                set_current_state(TASK_RUNNING);
1197                remove_wait_queue(&pp->wait, &wait);
1198        }
1199        spin_unlock_irqrestore(&pp->lock, flags);
1200        if (rc)
1201                return rc;
1202        if (pp->cmd.status != 0)
1203                pp->cmd.reply_len = 0;
1204        size = sizeof(hdr) + pp->cmd.reply_len;
1205        if (count < size)
1206                size = count;
1207        rc = size;
1208        hdr.status = pp->cmd.status;
1209        hdr.reply_len = pp->cmd.reply_len;
1210        if (copy_to_user(buf, &hdr, sizeof(hdr)))
1211                return -EFAULT;
1212        size -= sizeof(hdr);
1213        if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1214                return -EFAULT;
1215        pp->busy = 0;
1216
1217        return rc;
1218}
1219
1220
1221static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1222                               char __user *buf, size_t count)
1223{
1224        /* Not implemented */
1225        msleep_interruptible(1000);
1226        return 0;
1227}
1228
1229
1230static ssize_t smu_read(struct file *file, char __user *buf,
1231                        size_t count, loff_t *ppos)
1232{
1233        struct smu_private *pp = file->private_data;
1234
1235        if (pp->mode == smu_file_commands)
1236                return smu_read_command(file, pp, buf, count);
1237        if (pp->mode == smu_file_events)
1238                return smu_read_events(file, pp, buf, count);
1239
1240        return -EBADFD;
1241}
1242
1243static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1244{
1245        struct smu_private *pp = file->private_data;
1246        unsigned int mask = 0;
1247        unsigned long flags;
1248
1249        if (pp == 0)
1250                return 0;
1251
1252        if (pp->mode == smu_file_commands) {
1253                poll_wait(file, &pp->wait, wait);
1254
1255                spin_lock_irqsave(&pp->lock, flags);
1256                if (pp->busy && pp->cmd.status != 1)
1257                        mask |= POLLIN;
1258                spin_unlock_irqrestore(&pp->lock, flags);
1259        } if (pp->mode == smu_file_events) {
1260                /* Not yet implemented */
1261        }
1262        return mask;
1263}
1264
1265static int smu_release(struct inode *inode, struct file *file)
1266{
1267        struct smu_private *pp = file->private_data;
1268        unsigned long flags;
1269        unsigned int busy;
1270
1271        if (pp == 0)
1272                return 0;
1273
1274        file->private_data = NULL;
1275
1276        /* Mark file as closing to avoid races with new request */
1277        spin_lock_irqsave(&pp->lock, flags);
1278        pp->mode = smu_file_closing;
1279        busy = pp->busy;
1280
1281        /* Wait for any pending request to complete */
1282        if (busy && pp->cmd.status == 1) {
1283                DECLARE_WAITQUEUE(wait, current);
1284
1285                add_wait_queue(&pp->wait, &wait);
1286                for (;;) {
1287                        set_current_state(TASK_UNINTERRUPTIBLE);
1288                        if (pp->cmd.status != 1)
1289                                break;
1290                        spin_unlock_irqrestore(&pp->lock, flags);
1291                        schedule();
1292                        spin_lock_irqsave(&pp->lock, flags);
1293                }
1294                set_current_state(TASK_RUNNING);
1295                remove_wait_queue(&pp->wait, &wait);
1296        }
1297        spin_unlock_irqrestore(&pp->lock, flags);
1298
1299        spin_lock_irqsave(&smu_clist_lock, flags);
1300        list_del(&pp->list);
1301        spin_unlock_irqrestore(&smu_clist_lock, flags);
1302        kfree(pp);
1303
1304        return 0;
1305}
1306
1307
1308static const struct file_operations smu_device_fops = {
1309        .llseek         = no_llseek,
1310        .read           = smu_read,
1311        .write          = smu_write,
1312        .poll           = smu_fpoll,
1313        .open           = smu_open,
1314        .release        = smu_release,
1315};
1316
1317static struct miscdevice pmu_device = {
1318        MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1319};
1320
1321static int smu_device_init(void)
1322{
1323        if (!smu)
1324                return -ENODEV;
1325        if (misc_register(&pmu_device) < 0)
1326                printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1327        return 0;
1328}
1329device_initcall(smu_device_init);
1330
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.