#include <linux/proc_fs.h>
#include <linux/seq_file.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 device *ldev;

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

                ldev = acpi_get_physical_device(dev->handle);
                seq_printf(seq, "%s\t  S%d\t%c%-8s  ",
                           dev->pnp.bus_id,
                           (u32) dev->wakeup.sleep_state,
                           dev->wakeup.flags.run_wake ? '*' : ' ',
                           (device_may_wakeup(&dev->dev)
                             || (ldev && device_may_wakeup(ldev))) ?
                               "enabled" : "disabled");
                if (ldev)
                        seq_printf(seq, "%s:%s",
                                   ldev->bus ? ldev->bus->name : "no-bus",
                                   dev_name(ldev));
                seq_printf(seq, "\n");
                put_device(ldev);

        }
        mutex_unlock(&acpi_device_lock);
        return 0;
}

static void physical_device_enable_wakeup(struct acpi_device *adev)
{
        struct device *dev = acpi_get_physical_device(adev->handle);

        if (dev && device_can_wakeup(dev)) {
                bool enable = !device_may_wakeup(dev);
                device_set_wakeup_enable(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;
}