proc.c

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#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/export.h>
#include <linux/suspend.h>
#include <linux/bcd.h>
#include <asm/uaccess.h>

#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

#ifdef CONFIG_X86
#include <linux/mc146818rtc.h>
#endif

#include "sleep.h"

#define _COMPONENT      ACPI_SYSTEM_COMPONENT

/*
 * this file provides support for:
 * /proc/acpi/alarm
 * /proc/acpi/wakeup
 */

ACPI_MODULE_NAME("sleep")

#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || !defined(CONFIG_X86)
/* use /sys/class/rtc/rtcX/wakealarm instead; it's not ACPI-specific */
#else
#define HAVE_ACPI_LEGACY_ALARM
#endif

#ifdef  HAVE_ACPI_LEGACY_ALARM

static u32 cmos_bcd_read(int offset, int rtc_control);

static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
{
    u32 sec, min, hr;
    u32 day, mo, yr, cent = 0;
    u32 today = 0;
    unsigned char rtc_control = 0;
    unsigned long flags;

    spin_lock_irqsave(&rtc_lock, flags);

    rtc_control = CMOS_READ(RTC_CONTROL);
    sec = cmos_bcd_read(RTC_SECONDS_ALARM, rtc_control);
    min = cmos_bcd_read(RTC_MINUTES_ALARM, rtc_control);
    hr = cmos_bcd_read(RTC_HOURS_ALARM, rtc_control);

    /* If we ever get an FACP with proper values... */
    if (acpi_gbl_FADT.day_alarm) {
        /* ACPI spec: only low 6 its should be cared */
        day = CMOS_READ(acpi_gbl_FADT.day_alarm) & 0x3F;
        if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
            day = bcd2bin(day);
    } else
        day = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
    if (acpi_gbl_FADT.month_alarm)
        mo = cmos_bcd_read(acpi_gbl_FADT.month_alarm, rtc_control);
    else {
        mo = cmos_bcd_read(RTC_MONTH, rtc_control);
        today = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
    }
    if (acpi_gbl_FADT.century)
        cent = cmos_bcd_read(acpi_gbl_FADT.century, rtc_control);

    yr = cmos_bcd_read(RTC_YEAR, rtc_control);

    spin_unlock_irqrestore(&rtc_lock, flags);

    /* we're trusting the FADT (see above) */
    if (!acpi_gbl_FADT.century)
        /* If we're not trusting the FADT, we should at least make it
         * right for _this_ century... ehm, what is _this_ century?
         *
         * TBD:
         *  ASAP: find piece of code in the kernel, e.g. star tracker driver,
         *        which we can trust to determine the century correctly. Atom
         *        watch driver would be nice, too...
         *
         *  if that has not happened, change for first release in 2050:
         *        if (yr<50)
         *                yr += 2100;
         *        else
         *                yr += 2000;   // current line of code
         *
         *  if that has not happened either, please do on 2099/12/31:23:59:59
         *        s/2000/2100
         *
         */
        yr += 2000;
    else
        yr += cent * 100;

    /*
     * Show correct dates for alarms up to a month into the future.
     * This solves issues for nearly all situations with the common
     * 30-day alarm clocks in PC hardware.
     */
    if (day < today) {
        if (mo < 12) {
            mo += 1;
        } else {
            mo = 1;
            yr += 1;
        }
    }

    seq_printf(seq, "%4.4u-", yr);
    (mo > 12) ? seq_puts(seq, "**-") : seq_printf(seq, "%2.2u-", mo);
    (day > 31) ? seq_puts(seq, "** ") : seq_printf(seq, "%2.2u ", day);
    (hr > 23) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", hr);
    (min > 59) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", min);
    (sec > 59) ? seq_puts(seq, "**\n") : seq_printf(seq, "%2.2u\n", sec);

    return 0;
}

static int acpi_system_alarm_open_fs(struct inode *inode, struct file *file)
{
    return single_open(file, acpi_system_alarm_seq_show, PDE(inode)->data);
}

static int get_date_field(char **p, u32 * value)
{
    char *next = NULL;
    char *string_end = NULL;
    int result = -EINVAL;

    /*
     * Try to find delimeter, only to insert null.  The end of the
     * string won't have one, but is still valid.
     */
    if (*p == NULL)
        return result;

    next = strpbrk(*p, "- :");
    if (next)
        *next++ = '\0';

    *value = simple_strtoul(*p, &string_end, 10);

    /* Signal success if we got a good digit */
    if (string_end != *p)
        result = 0;

    if (next)
        *p = next;
    else
        *p = NULL;

    return result;
}

/* Read a possibly BCD register, always return binary */
static u32 cmos_bcd_read(int offset, int rtc_control)
{
    u32 val = CMOS_READ(offset);
    if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
        val = bcd2bin(val);
    return val;
}

/* Write binary value into possibly BCD register */
static void cmos_bcd_write(u32 val, int offset, int rtc_control)
{
    if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
        val = bin2bcd(val);
    CMOS_WRITE(val, offset);
}

static ssize_t
acpi_system_write_alarm(struct file *file,
            const char __user * buffer, size_t count, loff_t * ppos)
{
    int result = 0;
    char alarm_string[30] = { '\0' };
    char *p = alarm_string;
    u32 sec, min, hr, day, mo, yr;
    int adjust = 0;
    unsigned char rtc_control = 0;

    if (count > sizeof(alarm_string) - 1)
        return -EINVAL;

    if (copy_from_user(alarm_string, buffer, count))
        return -EFAULT;

    alarm_string[count] = '\0';

    /* check for time adjustment */
    if (alarm_string[0] == '+') {
        p++;
        adjust = 1;
    }

    if ((result = get_date_field(&p, &yr)))
        goto end;
    if ((result = get_date_field(&p, &mo)))
        goto end;
    if ((result = get_date_field(&p, &day)))
        goto end;
    if ((result = get_date_field(&p, &hr)))
        goto end;
    if ((result = get_date_field(&p, &min)))
        goto end;
    if ((result = get_date_field(&p, &sec)))
        goto end;

    spin_lock_irq(&rtc_lock);

    rtc_control = CMOS_READ(RTC_CONTROL);

    if (adjust) {
        yr += cmos_bcd_read(RTC_YEAR, rtc_control);
        mo += cmos_bcd_read(RTC_MONTH, rtc_control);
        day += cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
        hr += cmos_bcd_read(RTC_HOURS, rtc_control);
        min += cmos_bcd_read(RTC_MINUTES, rtc_control);
        sec += cmos_bcd_read(RTC_SECONDS, rtc_control);
    }

    spin_unlock_irq(&rtc_lock);

    if (sec > 59) {
        min += sec/60;
        sec = sec%60;
    }
    if (min > 59) {
        hr += min/60;
        min = min%60;
    }
    if (hr > 23) {
        day += hr/24;
        hr = hr%24;
    }
    if (day > 31) {
        mo += day/32;
        day = day%32;
    }
    if (mo > 12) {
        yr += mo/13;
        mo = mo%13;
    }

    spin_lock_irq(&rtc_lock);
    /*
     * Disable alarm interrupt before setting alarm timer or else
     * when ACPI_EVENT_RTC is enabled, a spurious ACPI interrupt occurs
     */
    rtc_control &= ~RTC_AIE;
    CMOS_WRITE(rtc_control, RTC_CONTROL);
    CMOS_READ(RTC_INTR_FLAGS);

    /* write the fields the rtc knows about */
    cmos_bcd_write(hr, RTC_HOURS_ALARM, rtc_control);
    cmos_bcd_write(min, RTC_MINUTES_ALARM, rtc_control);
    cmos_bcd_write(sec, RTC_SECONDS_ALARM, rtc_control);

    /*
     * If the system supports an enhanced alarm it will have non-zero
     * offsets into the CMOS RAM here -- which for some reason are pointing
     * to the RTC area of memory.
     */
    if (acpi_gbl_FADT.day_alarm)
        cmos_bcd_write(day, acpi_gbl_FADT.day_alarm, rtc_control);
    if (acpi_gbl_FADT.month_alarm)
        cmos_bcd_write(mo, acpi_gbl_FADT.month_alarm, rtc_control);
    if (acpi_gbl_FADT.century) {
        if (adjust)
            yr += cmos_bcd_read(acpi_gbl_FADT.century, rtc_control) * 100;
        cmos_bcd_write(yr / 100, acpi_gbl_FADT.century, rtc_control);
    }
    /* enable the rtc alarm interrupt */
    rtc_control |= RTC_AIE;
    CMOS_WRITE(rtc_control, RTC_CONTROL);
    CMOS_READ(RTC_INTR_FLAGS);

    spin_unlock_irq(&rtc_lock);

    acpi_clear_event(ACPI_EVENT_RTC);
    acpi_enable_event(ACPI_EVENT_RTC, 0);

    *ppos += count;

    result = 0;
      end:
    return result ? result : count;
}
#endif              /* HAVE_ACPI_LEGACY_ALARM */

static int
acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)
{
    struct list_head *node, *next;

    seq_printf(seq, "Device\tS-state\t  Status   Sysfs node\n");

    mutex_lock(&acpi_device_lock);
    list_for_each_safe(node, next, &acpi_wakeup_device_list) {
        struct acpi_device *dev =
            container_of(node, struct acpi_device, wakeup_list);
        struct acpi_device_physical_node *entry;

        if (!dev->wakeup.flags.valid)
            continue;

        seq_printf(seq, "%s\t  S%d\t",
               dev->pnp.bus_id,
               (u32) dev->wakeup.sleep_state);

        if (!dev->physical_node_count)
            seq_printf(seq, "%c%-8s\n",
                dev->wakeup.flags.run_wake ?
                '*' : ' ', "disabled");
        else {
            struct device *ldev;
            list_for_each_entry(entry, &dev->physical_node_list,
                    node) {
                ldev = get_device(entry->dev);
                if (!ldev)
                    continue;

                if (&entry->node !=
                        dev->physical_node_list.next)
                    seq_printf(seq, "\t\t");

                seq_printf(seq, "%c%-8s  %s:%s\n",
                    dev->wakeup.flags.run_wake ? '*' : ' ',
                    (device_may_wakeup(&dev->dev) ||
                    (ldev && device_may_wakeup(ldev))) ?
                    "enabled" : "disabled",
                    ldev->bus ? ldev->bus->name :
                    "no-bus", dev_name(ldev));
                put_device(ldev);
            }
        }
    }
    mutex_unlock(&acpi_device_lock);
    return 0;
}

static void physical_device_enable_wakeup(struct acpi_device *adev)
{
    struct acpi_device_physical_node *entry;

    list_for_each_entry(entry,
        &adev->physical_node_list, node)
        if (entry->dev && device_can_wakeup(entry->dev)) {
            bool enable = !device_may_wakeup(entry->dev);
            device_set_wakeup_enable(entry->dev, enable);
        }
}

static ssize_t
acpi_system_write_wakeup_device(struct file *file,
                const char __user * buffer,
                size_t count, loff_t * ppos)
{
    struct list_head *node, *next;
    char strbuf[5];
    char str[5] = "";
    unsigned int len = count;

    if (len > 4)
        len = 4;
    if (len < 0)
        return -EFAULT;

    if (copy_from_user(strbuf, buffer, len))
        return -EFAULT;
    strbuf[len] = '\0';
    sscanf(strbuf, "%s", str);

    mutex_lock(&acpi_device_lock);
    list_for_each_safe(node, next, &acpi_wakeup_device_list) {
        struct acpi_device *dev =
            container_of(node, struct acpi_device, wakeup_list);
        if (!dev->wakeup.flags.valid)
            continue;

        if (!strncmp(dev->pnp.bus_id, str, 4)) {
            if (device_can_wakeup(&dev->dev)) {
                bool enable = !device_may_wakeup(&dev->dev);
                device_set_wakeup_enable(&dev->dev, enable);
            } else {
                physical_device_enable_wakeup(dev);
            }
            break;
        }
    }
    mutex_unlock(&acpi_device_lock);
    return count;
}

static int
acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
{
    return single_open(file, acpi_system_wakeup_device_seq_show,
               PDE(inode)->data);
}

static const struct file_operations acpi_system_wakeup_device_fops = {
    .owner = THIS_MODULE,
    .open = acpi_system_wakeup_device_open_fs,
    .read = seq_read,
    .write = acpi_system_write_wakeup_device,
    .llseek = seq_lseek,
    .release = single_release,
};

#ifdef  HAVE_ACPI_LEGACY_ALARM
static const struct file_operations acpi_system_alarm_fops = {
    .owner = THIS_MODULE,
    .open = acpi_system_alarm_open_fs,
    .read = seq_read,
    .write = acpi_system_write_alarm,
    .llseek = seq_lseek,
    .release = single_release,
};

static u32 rtc_handler(void *context)
{
    acpi_clear_event(ACPI_EVENT_RTC);
    acpi_disable_event(ACPI_EVENT_RTC, 0);

    return ACPI_INTERRUPT_HANDLED;
}
#endif              /* HAVE_ACPI_LEGACY_ALARM */

int __init acpi_sleep_proc_init(void)
{
#ifdef  HAVE_ACPI_LEGACY_ALARM
    /* 'alarm' [R/W] */
    proc_create("alarm", S_IFREG | S_IRUGO | S_IWUSR,
            acpi_root_dir, &acpi_system_alarm_fops);

    acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
    /*
     * Disable the RTC event after installing RTC handler.
     * Only when RTC alarm is set will it be enabled.
     */
    acpi_clear_event(ACPI_EVENT_RTC);
    acpi_disable_event(ACPI_EVENT_RTC, 0);
#endif              /* HAVE_ACPI_LEGACY_ALARM */

    /* 'wakeup device' [R/W] */
    proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
            acpi_root_dir, &acpi_system_wakeup_device_fops);

    return 0;
}