linux/drivers/acpi/proc.c
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   1#include <linux/proc_fs.h>
   2#include <linux/seq_file.h>
   3#include <linux/export.h>
   4#include <linux/suspend.h>
   5#include <linux/bcd.h>
   6#include <asm/uaccess.h>
   7
   8#include <acpi/acpi_bus.h>
   9#include <acpi/acpi_drivers.h>
  10
  11#ifdef CONFIG_X86
  12#include <linux/mc146818rtc.h>
  13#endif
  14
  15#include "sleep.h"
  16
  17#define _COMPONENT              ACPI_SYSTEM_COMPONENT
  18
  19/*
  20 * this file provides support for:
  21 * /proc/acpi/alarm
  22 * /proc/acpi/wakeup
  23 */
  24
  25ACPI_MODULE_NAME("sleep")
  26
  27#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || !defined(CONFIG_X86)
  28/* use /sys/class/rtc/rtcX/wakealarm instead; it's not ACPI-specific */
  29#else
  30#define HAVE_ACPI_LEGACY_ALARM
  31#endif
  32
  33#ifdef  HAVE_ACPI_LEGACY_ALARM
  34
  35static u32 cmos_bcd_read(int offset, int rtc_control);
  36
  37static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
  38{
  39        u32 sec, min, hr;
  40        u32 day, mo, yr, cent = 0;
  41        u32 today = 0;
  42        unsigned char rtc_control = 0;
  43        unsigned long flags;
  44
  45        spin_lock_irqsave(&rtc_lock, flags);
  46
  47        rtc_control = CMOS_READ(RTC_CONTROL);
  48        sec = cmos_bcd_read(RTC_SECONDS_ALARM, rtc_control);
  49        min = cmos_bcd_read(RTC_MINUTES_ALARM, rtc_control);
  50        hr = cmos_bcd_read(RTC_HOURS_ALARM, rtc_control);
  51
  52        /* If we ever get an FACP with proper values... */
  53        if (acpi_gbl_FADT.day_alarm) {
  54                /* ACPI spec: only low 6 its should be cared */
  55                day = CMOS_READ(acpi_gbl_FADT.day_alarm) & 0x3F;
  56                if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
  57                        day = bcd2bin(day);
  58        } else
  59                day = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
  60        if (acpi_gbl_FADT.month_alarm)
  61                mo = cmos_bcd_read(acpi_gbl_FADT.month_alarm, rtc_control);
  62        else {
  63                mo = cmos_bcd_read(RTC_MONTH, rtc_control);
  64                today = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
  65        }
  66        if (acpi_gbl_FADT.century)
  67                cent = cmos_bcd_read(acpi_gbl_FADT.century, rtc_control);
  68
  69        yr = cmos_bcd_read(RTC_YEAR, rtc_control);
  70
  71        spin_unlock_irqrestore(&rtc_lock, flags);
  72
  73        /* we're trusting the FADT (see above) */
  74        if (!acpi_gbl_FADT.century)
  75                /* If we're not trusting the FADT, we should at least make it
  76                 * right for _this_ century... ehm, what is _this_ century?
  77                 *
  78                 * TBD:
  79                 *  ASAP: find piece of code in the kernel, e.g. star tracker driver,
  80                 *        which we can trust to determine the century correctly. Atom
  81                 *        watch driver would be nice, too...
  82                 *
  83                 *  if that has not happened, change for first release in 2050:
  84                 *        if (yr<50)
  85                 *                yr += 2100;
  86                 *        else
  87                 *                yr += 2000;   // current line of code
  88                 *
  89                 *  if that has not happened either, please do on 2099/12/31:23:59:59
  90                 *        s/2000/2100
  91                 *
  92                 */
  93                yr += 2000;
  94        else
  95                yr += cent * 100;
  96
  97        /*
  98         * Show correct dates for alarms up to a month into the future.
  99         * This solves issues for nearly all situations with the common
 100         * 30-day alarm clocks in PC hardware.
 101         */
 102        if (day < today) {
 103                if (mo < 12) {
 104                        mo += 1;
 105                } else {
 106                        mo = 1;
 107                        yr += 1;
 108                }
 109        }
 110
 111        seq_printf(seq, "%4.4u-", yr);
 112        (mo > 12) ? seq_puts(seq, "**-") : seq_printf(seq, "%2.2u-", mo);
 113        (day > 31) ? seq_puts(seq, "** ") : seq_printf(seq, "%2.2u ", day);
 114        (hr > 23) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", hr);
 115        (min > 59) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", min);
 116        (sec > 59) ? seq_puts(seq, "**\n") : seq_printf(seq, "%2.2u\n", sec);
 117
 118        return 0;
 119}
 120
 121static int acpi_system_alarm_open_fs(struct inode *inode, struct file *file)
 122{
 123        return single_open(file, acpi_system_alarm_seq_show, PDE(inode)->data);
 124}
 125
 126static int get_date_field(char **p, u32 * value)
 127{
 128        char *next = NULL;
 129        char *string_end = NULL;
 130        int result = -EINVAL;
 131
 132        /*
 133         * Try to find delimeter, only to insert null.  The end of the
 134         * string won't have one, but is still valid.
 135         */
 136        if (*p == NULL)
 137                return result;
 138
 139        next = strpbrk(*p, "- :");
 140        if (next)
 141                *next++ = '\0';
 142
 143        *value = simple_strtoul(*p, &string_end, 10);
 144
 145        /* Signal success if we got a good digit */
 146        if (string_end != *p)
 147                result = 0;
 148
 149        if (next)
 150                *p = next;
 151        else
 152                *p = NULL;
 153
 154        return result;
 155}
 156
 157/* Read a possibly BCD register, always return binary */
 158static u32 cmos_bcd_read(int offset, int rtc_control)
 159{
 160        u32 val = CMOS_READ(offset);
 161        if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
 162                val = bcd2bin(val);
 163        return val;
 164}
 165
 166/* Write binary value into possibly BCD register */
 167static void cmos_bcd_write(u32 val, int offset, int rtc_control)
 168{
 169        if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
 170                val = bin2bcd(val);
 171        CMOS_WRITE(val, offset);
 172}
 173
 174static ssize_t
 175acpi_system_write_alarm(struct file *file,
 176                        const char __user * buffer, size_t count, loff_t * ppos)
 177{
 178        int result = 0;
 179        char alarm_string[30] = { '\0' };
 180        char *p = alarm_string;
 181        u32 sec, min, hr, day, mo, yr;
 182        int adjust = 0;
 183        unsigned char rtc_control = 0;
 184
 185        if (count > sizeof(alarm_string) - 1)
 186                return -EINVAL;
 187
 188        if (copy_from_user(alarm_string, buffer, count))
 189                return -EFAULT;
 190
 191        alarm_string[count] = '\0';
 192
 193        /* check for time adjustment */
 194        if (alarm_string[0] == '+') {
 195                p++;
 196                adjust = 1;
 197        }
 198
 199        if ((result = get_date_field(&p, &yr)))
 200                goto end;
 201        if ((result = get_date_field(&p, &mo)))
 202                goto end;
 203        if ((result = get_date_field(&p, &day)))
 204                goto end;
 205        if ((result = get_date_field(&p, &hr)))
 206                goto end;
 207        if ((result = get_date_field(&p, &min)))
 208                goto end;
 209        if ((result = get_date_field(&p, &sec)))
 210                goto end;
 211
 212        spin_lock_irq(&rtc_lock);
 213
 214        rtc_control = CMOS_READ(RTC_CONTROL);
 215
 216        if (adjust) {
 217                yr += cmos_bcd_read(RTC_YEAR, rtc_control);
 218                mo += cmos_bcd_read(RTC_MONTH, rtc_control);
 219                day += cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
 220                hr += cmos_bcd_read(RTC_HOURS, rtc_control);
 221                min += cmos_bcd_read(RTC_MINUTES, rtc_control);
 222                sec += cmos_bcd_read(RTC_SECONDS, rtc_control);
 223        }
 224
 225        spin_unlock_irq(&rtc_lock);
 226
 227        if (sec > 59) {
 228                min += sec/60;
 229                sec = sec%60;
 230        }
 231        if (min > 59) {
 232                hr += min/60;
 233                min = min%60;
 234        }
 235        if (hr > 23) {
 236                day += hr/24;
 237                hr = hr%24;
 238        }
 239        if (day > 31) {
 240                mo += day/32;
 241                day = day%32;
 242        }
 243        if (mo > 12) {
 244                yr += mo/13;
 245                mo = mo%13;
 246        }
 247
 248        spin_lock_irq(&rtc_lock);
 249        /*
 250         * Disable alarm interrupt before setting alarm timer or else
 251         * when ACPI_EVENT_RTC is enabled, a spurious ACPI interrupt occurs
 252         */
 253        rtc_control &= ~RTC_AIE;
 254        CMOS_WRITE(rtc_control, RTC_CONTROL);
 255        CMOS_READ(RTC_INTR_FLAGS);
 256
 257        /* write the fields the rtc knows about */
 258        cmos_bcd_write(hr, RTC_HOURS_ALARM, rtc_control);
 259        cmos_bcd_write(min, RTC_MINUTES_ALARM, rtc_control);
 260        cmos_bcd_write(sec, RTC_SECONDS_ALARM, rtc_control);
 261
 262        /*
 263         * If the system supports an enhanced alarm it will have non-zero
 264         * offsets into the CMOS RAM here -- which for some reason are pointing
 265         * to the RTC area of memory.
 266         */
 267        if (acpi_gbl_FADT.day_alarm)
 268                cmos_bcd_write(day, acpi_gbl_FADT.day_alarm, rtc_control);
 269        if (acpi_gbl_FADT.month_alarm)
 270                cmos_bcd_write(mo, acpi_gbl_FADT.month_alarm, rtc_control);
 271        if (acpi_gbl_FADT.century) {
 272                if (adjust)
 273                        yr += cmos_bcd_read(acpi_gbl_FADT.century, rtc_control) * 100;
 274                cmos_bcd_write(yr / 100, acpi_gbl_FADT.century, rtc_control);
 275        }
 276        /* enable the rtc alarm interrupt */
 277        rtc_control |= RTC_AIE;
 278        CMOS_WRITE(rtc_control, RTC_CONTROL);
 279        CMOS_READ(RTC_INTR_FLAGS);
 280
 281        spin_unlock_irq(&rtc_lock);
 282
 283        acpi_clear_event(ACPI_EVENT_RTC);
 284        acpi_enable_event(ACPI_EVENT_RTC, 0);
 285
 286        *ppos += count;
 287
 288        result = 0;
 289      end:
 290        return result ? result : count;
 291}
 292#endif                          /* HAVE_ACPI_LEGACY_ALARM */
 293
 294static int
 295acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)
 296{
 297        struct list_head *node, *next;
 298
 299        seq_printf(seq, "Device\tS-state\t  Status   Sysfs node\n");
 300
 301        mutex_lock(&acpi_device_lock);
 302        list_for_each_safe(node, next, &acpi_wakeup_device_list) {
 303                struct acpi_device *dev =
 304                    container_of(node, struct acpi_device, wakeup_list);
 305                struct device *ldev;
 306
 307                if (!dev->wakeup.flags.valid)
 308                        continue;
 309
 310                ldev = acpi_get_physical_device(dev->handle);
 311                seq_printf(seq, "%s\t  S%d\t%c%-8s  ",
 312                           dev->pnp.bus_id,
 313                           (u32) dev->wakeup.sleep_state,
 314                           dev->wakeup.flags.run_wake ? '*' : ' ',
 315                           (device_may_wakeup(&dev->dev)
 316                             || (ldev && device_may_wakeup(ldev))) ?
 317                               "enabled" : "disabled");
 318                if (ldev)
 319                        seq_printf(seq, "%s:%s",
 320                                   ldev->bus ? ldev->bus->name : "no-bus",
 321                                   dev_name(ldev));
 322                seq_printf(seq, "\n");
 323                put_device(ldev);
 324
 325        }
 326        mutex_unlock(&acpi_device_lock);
 327        return 0;
 328}
 329
 330static void physical_device_enable_wakeup(struct acpi_device *adev)
 331{
 332        struct device *dev = acpi_get_physical_device(adev->handle);
 333
 334        if (dev && device_can_wakeup(dev)) {
 335                bool enable = !device_may_wakeup(dev);
 336                device_set_wakeup_enable(dev, enable);
 337        }
 338}
 339
 340static ssize_t
 341acpi_system_write_wakeup_device(struct file *file,
 342                                const char __user * buffer,
 343                                size_t count, loff_t * ppos)
 344{
 345        struct list_head *node, *next;
 346        char strbuf[5];
 347        char str[5] = "";
 348        unsigned int len = count;
 349
 350        if (len > 4)
 351                len = 4;
 352        if (len < 0)
 353                return -EFAULT;
 354
 355        if (copy_from_user(strbuf, buffer, len))
 356                return -EFAULT;
 357        strbuf[len] = '\0';
 358        sscanf(strbuf, "%s", str);
 359
 360        mutex_lock(&acpi_device_lock);
 361        list_for_each_safe(node, next, &acpi_wakeup_device_list) {
 362                struct acpi_device *dev =
 363                    container_of(node, struct acpi_device, wakeup_list);
 364                if (!dev->wakeup.flags.valid)
 365                        continue;
 366
 367                if (!strncmp(dev->pnp.bus_id, str, 4)) {
 368                        if (device_can_wakeup(&dev->dev)) {
 369                                bool enable = !device_may_wakeup(&dev->dev);
 370                                device_set_wakeup_enable(&dev->dev, enable);
 371                        } else {
 372                                physical_device_enable_wakeup(dev);
 373                        }
 374                        break;
 375                }
 376        }
 377        mutex_unlock(&acpi_device_lock);
 378        return count;
 379}
 380
 381static int
 382acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
 383{
 384        return single_open(file, acpi_system_wakeup_device_seq_show,
 385                           PDE(inode)->data);
 386}
 387
 388static const struct file_operations acpi_system_wakeup_device_fops = {
 389        .owner = THIS_MODULE,
 390        .open = acpi_system_wakeup_device_open_fs,
 391        .read = seq_read,
 392        .write = acpi_system_write_wakeup_device,
 393        .llseek = seq_lseek,
 394        .release = single_release,
 395};
 396
 397#ifdef  HAVE_ACPI_LEGACY_ALARM
 398static const struct file_operations acpi_system_alarm_fops = {
 399        .owner = THIS_MODULE,
 400        .open = acpi_system_alarm_open_fs,
 401        .read = seq_read,
 402        .write = acpi_system_write_alarm,
 403        .llseek = seq_lseek,
 404        .release = single_release,
 405};
 406
 407static u32 rtc_handler(void *context)
 408{
 409        acpi_clear_event(ACPI_EVENT_RTC);
 410        acpi_disable_event(ACPI_EVENT_RTC, 0);
 411
 412        return ACPI_INTERRUPT_HANDLED;
 413}
 414#endif                          /* HAVE_ACPI_LEGACY_ALARM */
 415
 416int __init acpi_sleep_proc_init(void)
 417{
 418#ifdef  HAVE_ACPI_LEGACY_ALARM
 419        /* 'alarm' [R/W] */
 420        proc_create("alarm", S_IFREG | S_IRUGO | S_IWUSR,
 421                    acpi_root_dir, &acpi_system_alarm_fops);
 422
 423        acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
 424        /*
 425         * Disable the RTC event after installing RTC handler.
 426         * Only when RTC alarm is set will it be enabled.
 427         */
 428        acpi_clear_event(ACPI_EVENT_RTC);
 429        acpi_disable_event(ACPI_EVENT_RTC, 0);
 430#endif                          /* HAVE_ACPI_LEGACY_ALARM */
 431
 432        /* 'wakeup device' [R/W] */
 433        proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
 434                    acpi_root_dir, &acpi_system_wakeup_device_fops);
 435
 436        return 0;
 437}
 438
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