firmware/powermgmt.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 by Heikki Hannikainen, Uwe Freese
 * Revisions copyright (C) 2005 by Gerald Van Baren
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include "config.h"
#include "system.h"
#include "kernel.h"
#include "thread.h"
#include "debug.h"
#if !defined(DX50) && !defined(DX90)
#include "adc.h"
#endif
#include "string.h"
#include "storage.h"
#include "power.h"
#include "audio.h"
#include "mp3_playback.h"
#include "usb.h"
#include "powermgmt.h"
#include "backlight.h"
#include "lcd.h"
#include "rtc.h"
#if CONFIG_TUNER
#include "fmradio.h"
#endif
#include "sound.h"
#ifdef HAVE_LCD_BITMAP
#include "font.h"
#endif
#include "logf.h"
#ifdef HAVE_REMOTE_LCD
#include "lcd-remote.h"
#endif
#if (CONFIG_PLATFORM & PLATFORM_HOSTED)
#include <time.h>
#endif

#if (defined(IAUDIO_X5) || defined(IAUDIO_M5) || defined(COWON_D2)) \
    && !defined (SIMULATOR)
#include "pcf50606.h"
#endif

/** Shared by sim **/
static int last_sent_battery_level = 100;
/* battery level (0-100%) */
int battery_percent = -1;
void send_battery_level_event(void);
static void set_sleep_timer(int seconds);

static bool sleeptimer_active = false;
static long sleeptimer_endtick;
/* Whether an active sleep timer should be restarted when a key is pressed */
static bool sleeptimer_key_restarts = false;
/* The number of seconds the sleep timer was last set to */
static unsigned int sleeptimer_duration = 0;

#if CONFIG_CHARGING
/* State of the charger input as seen by the power thread */
enum charger_input_state_type charger_input_state;
/* Power inputs as seen by the power thread */
unsigned int power_thread_inputs;
#if CONFIG_CHARGING >= CHARGING_MONITOR
/* Charging state (mode) as seen by the power thread */
enum charge_state_type charge_state = DISCHARGING;
#endif
#endif /* CONFIG_CHARGING */

static int shutdown_timeout = 0;

void handle_auto_poweroff(void);
static int poweroff_timeout = 0;
static long last_event_tick = 0;

#if (CONFIG_BATTERY_MEASURE & PERCENTAGE_MEASURE) == PERCENTAGE_MEASURE
int _battery_voltage(void) { return -1; }

const unsigned short percent_to_volt_discharge[BATTERY_TYPES_COUNT][11];
const unsigned short percent_to_volt_charge[11];

#elif (CONFIG_BATTERY_MEASURE & VOLTAGE_MEASURE) == VOLTAGE_MEASURE
int _battery_level(void) { return -1; }
/*
 * Average battery voltage and charger voltage, filtered via a digital
 * exponential filter (aka. exponential moving average, scaled):
 * avgbat = y[n] = (N-1)/N*y[n-1] + x[n]. battery_millivolts = y[n] / N.
 */
static unsigned int avgbat;
/* filtered battery voltage, millivolts */
static unsigned int battery_millivolts;
#elif (CONFIG_BATTERY_MEASURE == 0)
int _battery_voltage(void) { return -1; }
int _battery_level(void) { return -1; }

const unsigned short percent_to_volt_discharge[BATTERY_TYPES_COUNT][11];
const unsigned short percent_to_volt_charge[11];
#endif

#if !(CONFIG_BATTERY_MEASURE & TIME_MEASURE)
static int powermgmt_est_runningtime_min;
int _battery_time(void) { return powermgmt_est_runningtime_min; }
#endif

/* default value, mAh */
static int battery_capacity = BATTERY_CAPACITY_DEFAULT;

#if BATTERY_TYPES_COUNT > 1
static int battery_type = 0;
#else
#define battery_type 0
#endif

/* Power history: power_history[0] is the newest sample */
unsigned short power_history[POWER_HISTORY_LEN] = {0};

#if (CONFIG_CPU == JZ4732) || (CONFIG_CPU == JZ4760B) || (CONFIG_PLATFORM & PLATFORM_HOSTED)
static char power_stack[DEFAULT_STACK_SIZE + POWERMGMT_DEBUG_STACK];
#else
static char power_stack[DEFAULT_STACK_SIZE/2 + POWERMGMT_DEBUG_STACK];
#endif
static const char power_thread_name[] = "power";


static int voltage_to_battery_level(int battery_millivolts);
static void battery_status_update(void);

#ifdef CURRENT_NORMAL   /*only used if we have run current*/
static int runcurrent(void);
#endif

void battery_read_info(int *voltage, int *level)
{
    int millivolts = _battery_voltage();
    int percent;

    if (voltage)
        *voltage = millivolts;

    if (level)  {
        percent = voltage_to_battery_level(millivolts);
        if (percent < 0)
            percent = _battery_level();
        *level = percent;
    }
}

#if BATTERY_TYPES_COUNT > 1
void set_battery_type(int type)
{
    if (type != battery_type) {
        if ((unsigned)type >= BATTERY_TYPES_COUNT)
            type = 0;

        battery_type = type;
        battery_status_update(); /* recalculate the battery status */
    }
}
#endif

#ifdef BATTERY_CAPACITY_MIN
void set_battery_capacity(int capacity)
{
    if (capacity > BATTERY_CAPACITY_MAX)
        capacity = BATTERY_CAPACITY_MAX;
    if (capacity < BATTERY_CAPACITY_MIN)
        capacity = BATTERY_CAPACITY_MIN;

    battery_capacity = capacity;

    battery_status_update(); /* recalculate the battery status */
}
#endif

int get_battery_capacity(void)
{
    return battery_capacity;
}

int battery_time(void)
{
#if ((CONFIG_BATTERY_MEASURE & TIME_MEASURE) == 0)

#ifndef CURRENT_NORMAL /* no estimation without current */
    return -1;
#endif
    if (battery_capacity <= 0) /* nor without capacity */
        return -1;

#endif
    return _battery_time();
}

/* Returns battery level in percent */
int battery_level(void)
{
#ifdef HAVE_BATTERY_SWITCH
    if ((power_input_status() & POWER_INPUT_BATTERY) == 0)
        return -1;
#endif
    return battery_percent;
}

/* Tells if the battery level is safe for disk writes */
bool battery_level_safe(void)
{
#if defined(NO_LOW_BATTERY_SHUTDOWN)
    return true;
#elif (CONFIG_BATTERY_MEASURE & PERCENTAGE_MEASURE)
    return (battery_percent > 0);
#elif defined(HAVE_BATTERY_SWITCH)
    /* Cannot rely upon the battery reading to be valid and the
     * device could be powered externally. */
    return input_millivolts() > battery_level_dangerous[battery_type];
#else
    return battery_millivolts > battery_level_dangerous[battery_type];
#endif
}

/* look into the percent_to_volt_* table and get a realistic battery level */
static int voltage_to_percent(int voltage, const short* table)
{
    if (voltage <= table[0]) {
        return 0;
    }
    else if (voltage >= table[10]) {
        return 100;
    }
    else {
        /* search nearest value */
        int i = 0;

        while (i < 10 && table[i+1] < voltage)
            i++;

        /* interpolate linear between the smaller and greater value */
        /* Tens digit, 10% per entry,  ones digit: interpolated */
        return i*10 + (voltage - table[i])*10 / (table[i+1] - table[i]);
    }
}

/* update battery level and estimated runtime, called once per minute or
 * when battery capacity / type settings are changed */
static int voltage_to_battery_level(int battery_millivolts)
{
    int level;

    if (battery_millivolts < 0)
        return -1;

#if CONFIG_CHARGING >= CHARGING_MONITOR
    if (charging_state()) {
        /* battery level is defined to be < 100% until charging is finished */
        level = voltage_to_percent(battery_millivolts,
                                   percent_to_volt_charge);
        if (level > 99)
            level = 99;
    }
    else
#endif /* CONFIG_CHARGING >= CHARGING_MONITOR */
    {
        /* DISCHARGING or error state */
        level = voltage_to_percent(battery_millivolts,
                                   percent_to_volt_discharge[battery_type]);
    }

    return level;
}

static void battery_status_update(void)
{
    int millivolt = battery_voltage();
    int level = _battery_level();

    if (level < 0)
        level = voltage_to_battery_level(millivolt);

#ifdef CURRENT_NORMAL  /*don't try to estimate run or charge
                        time without normal current defined*/
    /* calculate estimated remaining running time */
#if CONFIG_CHARGING >= CHARGING_MONITOR
    if (charging_state()) {
        /* charging: remaining charging time */
        powermgmt_est_runningtime_min = (100 - level)*battery_capacity*60
                / 100 / (CURRENT_MAX_CHG - runcurrent());
    }
    else
#endif

    /* discharging: remaining running time */
    if (level > 0 && (millivolt > percent_to_volt_discharge[battery_type][0]
        || millivolt < 0)) {
        /* linear extrapolation */
        powermgmt_est_runningtime_min = (level + battery_percent)*60
                * battery_capacity / 200 / runcurrent();
    }
    if (0 > powermgmt_est_runningtime_min) {
        powermgmt_est_runningtime_min = 0;
    }
#endif

    battery_percent = level;
    send_battery_level_event();
}

#ifdef CURRENT_NORMAL /*check that we have a current defined in a config file*/

/*
 * Estimate how much current we are drawing just to run.
 */
static int runcurrent(void)
{
    int current = CURRENT_NORMAL;

#ifndef BOOTLOADER
    if (usb_inserted()
#ifdef HAVE_USB_POWER
    #if (CURRENT_USB < CURRENT_NORMAL)
       || usb_powered_only()
    #else
       && !usb_powered_only()
    #endif
#endif
    ) {
        current = CURRENT_USB;
    }

#if defined(HAVE_BACKLIGHT)
    if (backlight_get_current_timeout() == 0) /* LED always on */
        current += CURRENT_BACKLIGHT;
#endif

#if defined(HAVE_RECORDING) && defined(CURRENT_RECORD)
    if (audio_status() & AUDIO_STATUS_RECORD)
        current += CURRENT_RECORD;
#endif

#ifdef HAVE_SPDIF_POWER
    if (spdif_powered())
        current += CURRENT_SPDIF_OUT;
#endif

#ifdef HAVE_REMOTE_LCD
    if (remote_detect())
        current += CURRENT_REMOTE;
#endif

#if defined(HAVE_ATA_POWER_OFF) && defined(CURRENT_ATA)
    if (ide_powered())
        current += CURRENT_ATA;
#endif

#endif /* BOOTLOADER */
    
    return current;
}

#endif  /* CURRENT_NORMAL */

/* Check to see whether or not we've received an alarm in the last second */
#ifdef HAVE_RTC_ALARM
static void power_thread_rtc_process(void)
{
    if (rtc_check_alarm_flag())
        rtc_enable_alarm(false);
}
#endif

/* switch off unit if battery level is too low for reliable operation */
bool query_force_shutdown(void)
{
#if defined(NO_LOW_BATTERY_SHUTDOWN)
    return false;
#elif CONFIG_BATTERY_MEASURE & PERCENTAGE_MEASURE
    return battery_percent == 0;
#elif defined(HAVE_BATTERY_SWITCH)
    /* Cannot rely upon the battery reading to be valid and the
     * device could be powered externally. */
    return input_millivolts() < battery_level_shutoff[battery_type];
#else
    return battery_millivolts < battery_level_shutoff[battery_type];
#endif
}

#if defined(HAVE_BATTERY_SWITCH) || defined(HAVE_RESET_BATTERY_FILTER)
/*
 * Reset the battery voltage filter to a new value and update the
 * status.
 */
void reset_battery_filter(int millivolts)
{
    avgbat = millivolts * BATT_AVE_SAMPLES;
    battery_millivolts = millivolts;
    battery_status_update();
}
#endif /* HAVE_BATTERY_SWITCH */

/** Generic charging algorithms for common charging types **/
#if CONFIG_CHARGING == 0 || CONFIG_CHARGING == CHARGING_SIMPLE
static inline void powermgmt_init_target(void)
{
    /* Nothing to do */
}

static inline void charging_algorithm_step(void)
{
    /* Nothing to do */
}

static inline void charging_algorithm_close(void)
{
    /* Nothing to do */
}
#elif CONFIG_CHARGING == CHARGING_MONITOR
/*
 * Monitor CHARGING/DISCHARGING state.
 */
static inline void powermgmt_init_target(void)
{
    /* Nothing to do */
}

static inline void charging_algorithm_step(void)
{
    switch (charger_input_state)
    {
    case CHARGER_PLUGGED:
    case CHARGER:
        if (charging_state()) {
            charge_state = CHARGING;
            break;
        }
    /* Fallthrough */
    case CHARGER_UNPLUGGED:
    case NO_CHARGER:
        charge_state = DISCHARGING;
        break;
    }
}

static inline void charging_algorithm_close(void)
{
    /* Nothing to do */
}
#endif /* CONFIG_CHARGING == * */

#if CONFIG_CHARGING
/* Shortcut function calls - compatibility, simplicity. */

/* Returns true if any power input is capable of charging. */
bool charger_inserted(void)
{
    return power_thread_inputs & POWER_INPUT_CHARGER;
}

/* Returns true if any power input is connected - charging-capable
 * or not. */
bool power_input_present(void)
{
    return power_thread_inputs & POWER_INPUT;
}

/*
 * Detect charger inserted. Return true if the state is transistional.
 */
static inline bool detect_charger(unsigned int pwr)
{
    /*
     * Detect charger plugged/unplugged transitions.  On a plugged or
     * unplugged event, we return immediately, run once through the main
     * loop (including the subroutines), and end up back here where we
     * transition to the appropriate steady state charger on/off state.
     */
    if (pwr & POWER_INPUT_CHARGER) {
        switch (charger_input_state)
        {
        case NO_CHARGER:
        case CHARGER_UNPLUGGED:
            charger_input_state = CHARGER_PLUGGED;
            break;

        case CHARGER_PLUGGED:
            queue_broadcast(SYS_CHARGER_CONNECTED, 0);
            last_sent_battery_level = 0;
            charger_input_state = CHARGER;
            break;

        case CHARGER:
            /* Steady state */
            return false;
        }
    }
    else {    /* charger not inserted */
        switch (charger_input_state)
        {
        case NO_CHARGER:
            /* Steady state */
            return false;

        case CHARGER_UNPLUGGED:
            queue_broadcast(SYS_CHARGER_DISCONNECTED, 0);
            last_sent_battery_level = 100;
            charger_input_state = NO_CHARGER;
            break;

        case CHARGER_PLUGGED:
        case CHARGER:
            charger_input_state = CHARGER_UNPLUGGED;
            break;
        }
    }

    /* Transitional state */
    return true;
}
#endif /* CONFIG_CHARGING */


#if CONFIG_BATTERY_MEASURE & VOLTAGE_MEASURE
/* Returns filtered battery voltage [millivolts] */
int battery_voltage(void)
{
    return battery_millivolts;
}

static void average_init(void)
{
    /* initialize the voltages for the exponential filter */
    avgbat = _battery_voltage() + 15;

#ifdef HAVE_DISK_STORAGE /* this adjustment is only needed for HD based */
    /* The battery voltage is usually a little lower directly after
       turning on, because the disk was used heavily. Raise it by 5% */
#if CONFIG_CHARGING
    if (!charger_inserted()) /* only if charger not connected */
#endif
    {
        avgbat += (percent_to_volt_discharge[battery_type][6] -
                   percent_to_volt_discharge[battery_type][5]) / 2;
    }
#endif /* HAVE_DISK_STORAGE */

    avgbat = avgbat * BATT_AVE_SAMPLES;
    battery_millivolts = power_history[0] = avgbat / BATT_AVE_SAMPLES;
}

static void average_step(void)
{
    avgbat += _battery_voltage() - avgbat / BATT_AVE_SAMPLES;
    /*
     * battery_millivolts is the millivolt-scaled filtered battery value.
     */
    battery_millivolts = avgbat / BATT_AVE_SAMPLES;
}

static void average_step_low(void)
{
    battery_millivolts = (_battery_voltage() + battery_millivolts + 1) / 2;
    avgbat += battery_millivolts - avgbat / BATT_AVE_SAMPLES;
}

static void init_battery_percent(void)
{
#if CONFIG_CHARGING
    if (charger_inserted()) {
        battery_percent = voltage_to_percent(battery_millivolts,
                            percent_to_volt_charge);
    }
    else
#endif
    {
        battery_percent = voltage_to_percent(battery_millivolts,
                            percent_to_volt_discharge[battery_type]);
        battery_percent += battery_percent < 100;
    }

}

static int power_hist_item(void)
{
    return battery_millivolts;
}
#define power_history_unit() battery_millivolts

#else
int battery_voltage(void)
{
    return -1;
}

static void average_init(void) {}
static void average_step(void) {}
static void average_step_low(void) {}
static void init_battery_percent(void)
{
    battery_percent = _battery_level();
}

static int power_hist_item(void)
{
    return battery_percent;
}
#endif

static void collect_power_history(void)
{
    /* rotate the power history */
    memmove(&power_history[1], &power_history[0],
            sizeof(power_history) - sizeof(power_history[0]));
    power_history[0] = power_hist_item();
}

/*
 * Monitor the presence of a charger and perform critical frequent steps
 * such as running the battery voltage filter.
 */
static inline void power_thread_step(void)
{
    /* If the power off timeout expires, the main thread has failed
       to shut down the system, and we need to force a power off */
    if (shutdown_timeout) {
        shutdown_timeout -= POWER_THREAD_STEP_TICKS;

        if (shutdown_timeout <= 0)
            power_off();
    }

#ifdef HAVE_RTC_ALARM
    power_thread_rtc_process();
#endif

    /*
     * Do a digital exponential filter.  We don't sample the battery if
     * the disk is spinning unless we are in USB mode (the disk will most
     * likely always be spinning in USB mode) or charging.
     */
    if (!storage_disk_is_active() || usb_inserted()
#if CONFIG_CHARGING >= CHARGING_MONITOR
            || charger_input_state == CHARGER
#endif
    ) {
        average_step();
        /* update battery status every time an update is available */
        battery_status_update();
    }
    else if (battery_percent < 8) {
        average_step_low();
        /* update battery status every time an update is available */
        battery_status_update();
        
        /*
         * If battery is low, observe voltage during disk activity.
         * Shut down if voltage drops below shutoff level and we are not
         * using NiMH or Alkaline batteries.
         */
        if (!shutdown_timeout && query_force_shutdown()) {
            sys_poweroff();
        }
    }
} /* power_thread_step */

static void power_thread(void)
{
    long next_power_hist;

    /* Delay reading the first battery level */
#ifdef MROBE_100
    while (_battery_voltage() > 4200) /* gives false readings initially */
#elif defined(DX50) || defined(DX90)
    while (_battery_voltage() < 1) /* can give false readings initially */
#endif
    {
        sleep(HZ/100);
    }

#if CONFIG_CHARGING
    /* Initialize power input status before calling other routines. */
    power_thread_inputs = power_input_status();
#endif

    /* initialize voltage averaging (if available) */
    average_init();
    /* get initial battery level value (in %) */
    init_battery_percent();
    /* get some initial data for the power curve */
    collect_power_history();
    /* call target specific init now */
    powermgmt_init_target();

    next_power_hist = current_tick + HZ*60;

    while (1)
    {
#if CONFIG_CHARGING
        unsigned int pwr = power_input_status();
#ifdef HAVE_BATTERY_SWITCH
        if ((pwr ^ power_thread_inputs) & POWER_INPUT_BATTERY) {
            sleep(HZ/10);
            reset_battery_filter(_battery_voltage());
        }
#endif
        power_thread_inputs = pwr;

        if (!detect_charger(pwr))
#endif /* CONFIG_CHARGING */
        {
            /* Steady state */
            sleep(POWER_THREAD_STEP_TICKS);

            /* Do common power tasks */
            power_thread_step();
        }

        /* Perform target tasks */
        charging_algorithm_step();

        /* check if some idle or sleep timer wears off */
        handle_auto_poweroff();

        if (TIME_AFTER(current_tick, next_power_hist)) {
            /* increment to ensure there is a record for every minute
             * rather than go forward from the current tick */
            next_power_hist += HZ*60;
            collect_power_history();
        }
    }
} /* power_thread */

void powermgmt_init(void)
{
    create_thread(power_thread, power_stack, sizeof(power_stack), 0,
                  power_thread_name IF_PRIO(, PRIORITY_SYSTEM)
                  IF_COP(, CPU));
}

/* Various hardware housekeeping tasks relating to shutting down the player */
void shutdown_hw(void)
{
    charging_algorithm_close();
    audio_stop();

    if (battery_level_safe()) { /* do not save on critical battery */
#ifdef HAVE_LCD_BITMAP
        font_unload_all();
#endif

/* Commit pending writes if needed. Even though we don't do write caching,
   things like flash translation layers may need this to commit scattered
   pages to there final locations. So far only used for iPod Nano 2G. */
#ifdef HAVE_STORAGE_FLUSH
        storage_flush();
#endif

        if (storage_disk_is_active())
            storage_spindown(1);
    }

#if CONFIG_CODEC == SWCODEC
    audiohw_close();
#else
    mp3_shutdown();
#endif

    /* If HD is still active we try to wait for spindown, otherwise the
       shutdown_timeout in power_thread_step will force a power off */
    while (storage_disk_is_active())
        sleep(HZ/10);

#ifndef HAVE_LCD_COLOR
    lcd_set_contrast(0);
#endif
#ifdef HAVE_REMOTE_LCD
    lcd_remote_set_contrast(0);
#endif
#ifdef HAVE_LCD_SHUTDOWN
    lcd_shutdown();
#endif

    /* Small delay to make sure all HW gets time to flush. Especially
       eeprom chips are quite slow and might be still writing the last
       byte. */
    sleep(HZ/4);
    power_off();
}

void set_poweroff_timeout(int timeout)
{
    poweroff_timeout = timeout;
}

void reset_poweroff_timer(void)
{
    last_event_tick = current_tick;
    if (sleeptimer_active && sleeptimer_key_restarts)
        set_sleep_timer(sleeptimer_duration);
}

void sys_poweroff(void)
{
#ifndef BOOTLOADER
    logf("sys_poweroff()");
    /* If the main thread fails to shut down the system, we will force a
       power off after an 20 second timeout - 28 seconds if recording */
    if (shutdown_timeout == 0) {
#if (defined(IAUDIO_X5) || defined(IAUDIO_M5) || defined(COWON_D2)) && !defined(SIMULATOR)
        pcf50606_reset_timeout(); /* Reset timer on first attempt only */
#endif
#ifdef HAVE_RECORDING
        if (audio_status() & AUDIO_STATUS_RECORD)
            shutdown_timeout += HZ*8;
#endif
#ifdef IPOD_NANO2G
        /* The FTL alone may take half a minute to shut down cleanly. */
        shutdown_timeout += HZ*60;
#else
        shutdown_timeout += HZ*20;
#endif
    }

    queue_broadcast(SYS_POWEROFF, 0);
#endif /* BOOTLOADER */
}

void cancel_shutdown(void)
{
    logf("cancel_shutdown()");

#if (defined(IAUDIO_X5) || defined(IAUDIO_M5) || defined(COWON_D2)) && !defined(SIMULATOR)
    /* TODO: Move some things to target/ tree */
    if (shutdown_timeout)
        pcf50606_reset_timeout();
#endif

    shutdown_timeout = 0;
}

/* Send system battery level update events on reaching certain significant
   levels. This must be called after battery_percent has been updated. */
void send_battery_level_event(void)
{
    static const int levels[] = { 5, 15, 30, 50, 0 };
    const int *level = levels;

    while (*level)
    {
        if (battery_percent <= *level && last_sent_battery_level > *level) {
            last_sent_battery_level = *level;
            queue_broadcast(SYS_BATTERY_UPDATE, last_sent_battery_level);
            break;
        }

        level++;
    }
}

void set_sleeptimer_duration(int minutes)
{
    set_sleep_timer(minutes * 60);
}

static void set_sleep_timer(int seconds)
{
    if (seconds) {
        sleeptimer_active  = true;
        sleeptimer_endtick = current_tick + seconds * HZ;
    }
    else {
        sleeptimer_active  = false;
        sleeptimer_endtick = 0;
    }
    sleeptimer_duration = seconds;
}

int get_sleep_timer(void)
{
    if (sleeptimer_active && (sleeptimer_endtick >= current_tick))
        return (sleeptimer_endtick - current_tick) / HZ;
    else
        return 0;
}

void set_keypress_restarts_sleep_timer(bool enable)
{
    sleeptimer_key_restarts = enable;
}

#ifndef BOOTLOADER
static void handle_sleep_timer(void)
{
    if (!sleeptimer_active)
      return;

    /* Handle sleeptimer */
    if (TIME_AFTER(current_tick, sleeptimer_endtick)) {
        if (usb_inserted()
#if CONFIG_CHARGING && !defined(HAVE_POWEROFF_WHILE_CHARGING)
            || charger_input_state != NO_CHARGER
#endif
        ) {
            DEBUGF("Sleep timer timeout. Stopping...\n");
            audio_pause();
            set_sleep_timer(0);
            backlight_off(); /* Nighty, nighty... */
        }
        else {
            DEBUGF("Sleep timer timeout. Shutting off...\n");
            sys_poweroff();
        }
    }
}
#endif /* BOOTLOADER */

/*
 * We shut off in the following cases:
 * 1) The unit is idle, not playing music
 * 2) The unit is playing music, but is paused
 * 3) The battery level has reached shutdown limit
 *
 * We do not shut off in the following cases:
 * 1) The USB is connected
 * 2) The charger is connected
 * 3) We are recording, or recording with pause
 * 4) The radio is playing
 */
void handle_auto_poweroff(void)
{
#ifndef BOOTLOADER
    long timeout = poweroff_timeout*60*HZ;
    int audio_stat = audio_status();
    long tick = current_tick;

    /*
     * Inhibit shutdown as long as the charger is plugged in.  If it is
     * unplugged, wait for a timeout period and then shut down.
     */
    if (audio_stat == AUDIO_STATUS_PLAY
#if CONFIG_CHARGING
        || charger_input_state == CHARGER
#endif
    ) {
        last_event_tick = current_tick;
    }

    if (!shutdown_timeout && query_force_shutdown()) {
        backlight_on();
        sys_poweroff();
    }

    if (timeout &&
#if CONFIG_TUNER
        !(get_radio_status() & FMRADIO_PLAYING) &&
#endif
        !usb_inserted() &&
        (audio_stat == 0 ||
         (audio_stat == (AUDIO_STATUS_PLAY | AUDIO_STATUS_PAUSE) &&
          !sleeptimer_active))) {

        if (TIME_AFTER(tick, last_event_tick + timeout)
#if !(CONFIG_PLATFORM & PLATFORM_HOSTED)
            && TIME_AFTER(tick, storage_last_disk_activity() + timeout)
#endif
        ) {
            sys_poweroff();
        }
    } else
        handle_sleep_timer();
#endif
}