firmware/backlight.c - rockbox - Gitiles

 /***************************************************************************
  *             __________               __   ___.
  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
  *                     \/            \/     \/    \/            \/
  * $Id$
  *
  * Copyright (C) 2002 by Linus Nielsen Feltzing
  *
  * 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 <stdlib.h>
 #include "cpu.h"
 #include "kernel.h"
 #include "thread.h"
 #include "i2c.h"
 #include "debug.h"
 #include "rtc.h"
 #include "usb.h"
 #include "power.h"
 #include "system.h"
 #include "button.h"
 #include "timer.h"
 #include "backlight.h"
 #include "lcd.h"

 #ifdef HAVE_REMOTE_LCD
 #include "lcd-remote.h"
 #endif
 #ifndef SIMULATOR
 #include "backlight-target.h"
 #endif

 #if !defined(BOOTLOADER)
 /* The whole driver should be built */
 #define BACKLIGHT_FULL_INIT
 #endif

 #ifdef SIMULATOR
 /* TODO: find a better way to do it but we need a kernel thread somewhere to
    handle this */
 extern void screen_dump(void);

 static inline void _backlight_on(void)
 {
     sim_backlight(100);
 }

 static inline void _backlight_off(void)
 {
     sim_backlight(0);
 }

 static inline void _backlight_set_brightness(int val)
 {
     (void)val;
 }

 static inline void _buttonlight_on(void)
 {
 }

 static inline void _buttonlight_off(void)
 {
 }

 static inline void _buttonlight_set_brightness(int val)
 {
     (void)val;
 }
 #ifdef HAVE_REMOTE_LCD
 static inline void _remote_backlight_on(void)
 {
     sim_remote_backlight(100);
 }

 static inline void _remote_backlight_off(void)
 {
     sim_remote_backlight(0);
 }
 #endif /* HAVE_REMOTE_LCD */

 #endif /* SIMULATOR */

 #if defined(HAVE_BACKLIGHT) && defined(BACKLIGHT_FULL_INIT)

 enum {
     BACKLIGHT_ON,
     BACKLIGHT_OFF,
 #ifdef HAVE_REMOTE_LCD
     REMOTE_BACKLIGHT_ON,
     REMOTE_BACKLIGHT_OFF,
 #endif
 #if defined(_BACKLIGHT_FADE_BOOST) || defined(_BACKLIGHT_FADE_ENABLE)
     BACKLIGHT_FADE_FINISH,
 #endif
 #ifdef HAVE_LCD_SLEEP
     LCD_SLEEP,
 #endif
 #ifdef HAVE_BUTTON_LIGHT
     BUTTON_LIGHT_ON,
     BUTTON_LIGHT_OFF,
 #endif
 #ifdef BACKLIGHT_DRIVER_CLOSE
     BACKLIGHT_QUIT,
 #endif
 };

 static void backlight_thread(void);
 static long backlight_stack[DEFAULT_STACK_SIZE/sizeof(long)];
 static const char backlight_thread_name[] = "backlight";
 static struct event_queue backlight_queue;
 #ifdef BACKLIGHT_DRIVER_CLOSE
 static struct thread_entry *backlight_thread_p = NULL;
 #endif

 static int backlight_timer SHAREDBSS_ATTR;
 static int backlight_timeout SHAREDBSS_ATTR;
 static int backlight_timeout_normal = 5*HZ;
 #if CONFIG_CHARGING
 static int backlight_timeout_plugged = 5*HZ;
 #endif
 #ifdef HAS_BUTTON_HOLD
 static int backlight_on_button_hold = 0;
 #endif

 #ifdef HAVE_BUTTON_LIGHT
 static int buttonlight_timer;
 int _buttonlight_timeout = 5*HZ;

 /* Update state of buttonlight according to timeout setting */
 static void buttonlight_update_state(void)
 {
     buttonlight_timer = _buttonlight_timeout;

     /* Buttonlight == OFF in the setting? */
     if (buttonlight_timer < 0)
     {
         buttonlight_timer = 0; /* Disable the timeout */
         _buttonlight_off();
     }
     else
         _buttonlight_on();
 }

 /* external interface */
 void buttonlight_on(void)
 {
     queue_remove_from_head(&backlight_queue, BUTTON_LIGHT_ON);
     queue_post(&backlight_queue, BUTTON_LIGHT_ON, 0);
 }

 void buttonlight_off(void)
 {
     queue_post(&backlight_queue, BUTTON_LIGHT_OFF, 0);
 }

 void buttonlight_set_timeout(int value)
 {
     _buttonlight_timeout = HZ * value;
     buttonlight_update_state();
 }

 #endif /* HAVE_BUTTON_LIGHT */

 #ifdef HAVE_REMOTE_LCD
 static int remote_backlight_timer;
 static int remote_backlight_timeout;
 static int remote_backlight_timeout_normal = 5*HZ;
 #if CONFIG_CHARGING
 static int remote_backlight_timeout_plugged = 5*HZ;
 #endif
 #ifdef HAS_REMOTE_BUTTON_HOLD
 static int remote_backlight_on_button_hold = 0;
 #endif
 #endif /* HAVE_REMOTE_LCD */

 #ifdef HAVE_LCD_SLEEP
 #ifdef HAVE_LCD_SLEEP_SETTING
 const signed char lcd_sleep_timeout_value[10] =
 {
     -1, 0, 5, 10, 15, 20, 30, 45, 60, 90
 };
 static int lcd_sleep_timeout = 10*HZ;
 #else
 /* Target defines needed value */
 static const int lcd_sleep_timeout = LCD_SLEEP_TIMEOUT;
 #endif

 static int lcd_sleep_timer = 0;

 void backlight_lcd_sleep_countdown(bool start)
 {
     if (!start)
     {
         /* Cancel the LCD sleep countdown */
         lcd_sleep_timer = 0;
         return;
     }

     /* Start LCD sleep countdown */
     if (lcd_sleep_timeout < 0)
     {
         lcd_sleep_timer = 0; /* Setting == Always */
         lcd_sleep();
     }
     else
     {
         lcd_sleep_timer = lcd_sleep_timeout;
     }
 }
 #endif /* HAVE_LCD_SLEEP */

 #if defined(HAVE_BACKLIGHT_PWM_FADING) && !defined(SIMULATOR)
 /* backlight fading */
 #define BL_PWM_INTERVAL 5  /* Cycle interval in ms */
 #define BL_PWM_BITS     8
 #define BL_PWM_COUNT    (1<<BL_PWM_BITS)

 /* s15.16 fixed point variables */
 static int32_t bl_fade_in_step  = ((BL_PWM_INTERVAL*BL_PWM_COUNT)<<16)/300;
 static int32_t bl_fade_out_step = ((BL_PWM_INTERVAL*BL_PWM_COUNT)<<16)/2000;
 static int32_t bl_dim_fraction  = 0;

 static int bl_dim_target  = 0;
 static int bl_dim_current = 0;
 static enum {DIM_STATE_START, DIM_STATE_MAIN} bl_dim_state = DIM_STATE_START;
 static bool bl_timer_active = false;

 static void backlight_isr(void)
 {
     int timer_period = (TIMER_FREQ*BL_PWM_INTERVAL/1000);
     bool idle = false;

     switch (bl_dim_state)
     {
       /* New cycle */
       case DIM_STATE_START:
         bl_dim_current = bl_dim_fraction >> 16;

         if (bl_dim_current > 0 && bl_dim_current < BL_PWM_COUNT)
         {
             _backlight_on_isr();
             timer_period = (timer_period * bl_dim_current) >> BL_PWM_BITS;
             bl_dim_state = DIM_STATE_MAIN;
         }
         else
         {
             if (bl_dim_current)
                 _backlight_on_isr();
             else
                 _backlight_off_isr();
             if (bl_dim_current == bl_dim_target)
                 idle = true;
         }
         if (bl_dim_current < bl_dim_target)
         {
             bl_dim_fraction = MIN(bl_dim_fraction + bl_fade_in_step,
                                   (BL_PWM_COUNT<<16));
         }
         else if (bl_dim_current > bl_dim_target)
         {
             bl_dim_fraction = MAX(bl_dim_fraction - bl_fade_out_step, 0);
         }
         break;

       /* Dim main screen */
       case DIM_STATE_MAIN:
         _backlight_off_isr();
         timer_period = (timer_period * (BL_PWM_COUNT - bl_dim_current))
                      >> BL_PWM_BITS;
         bl_dim_state = DIM_STATE_START;
         break ;
     }
     if (idle)
     {
 #if defined(_BACKLIGHT_FADE_BOOST) || defined(_BACKLIGHT_FADE_ENABLE)
         queue_post(&backlight_queue, BACKLIGHT_FADE_FINISH, 0);
 #endif
         timer_unregister();
         bl_timer_active = false;
     }
     else
         timer_set_period(timer_period);
 }

 static void backlight_switch(void)
 {
     if (bl_dim_target > (BL_PWM_COUNT/2))
     {
         _backlight_on_normal();
         bl_dim_fraction = (BL_PWM_COUNT<<16);
     }
     else
     {
         _backlight_off_normal();
         bl_dim_fraction = 0;
     }
 }

 static void backlight_release_timer(void)
 {
 #ifdef _BACKLIGHT_FADE_BOOST
     cpu_boost(false);
 #endif
     timer_unregister();
     bl_timer_active = false;
     backlight_switch();
 }

 static void backlight_dim(int value)
 {
     /* protect from extraneous calls with the same target value */
     if (value == bl_dim_target)
         return;

     bl_dim_target = value;

     if (bl_timer_active)
         return ;

     if (timer_register(0, backlight_release_timer, 2, 0, backlight_isr
                        IF_COP(, CPU)))
     {
 #ifdef _BACKLIGHT_FADE_BOOST
         /* Prevent cpu frequency changes while dimming. */
         cpu_boost(true);
 #endif
         bl_timer_active = true;
     }
     else
         backlight_switch();
 }

 static void _backlight_on(void)
 {
 #ifdef HAVE_LCD_SLEEP
     backlight_lcd_sleep_countdown(false);
 #endif

     if (bl_fade_in_step > 0)
     {
 #ifdef _BACKLIGHT_FADE_ENABLE
         _backlight_hw_enable(true);
 #endif
         backlight_dim(BL_PWM_COUNT);
     }
     else
     {
         bl_dim_target = BL_PWM_COUNT;
         bl_dim_fraction = (BL_PWM_COUNT<<16);
         _backlight_on_normal();
     }
 }

 static void _backlight_off(void)
 {
     if (bl_fade_out_step > 0)
     {
         backlight_dim(0);
     }
     else
     {
         bl_dim_target = bl_dim_fraction = 0;
         _backlight_off_normal();
     }

 #ifdef HAVE_LCD_SLEEP
     backlight_lcd_sleep_countdown(true);
 #endif
 }

 void backlight_set_fade_in(int value)
 {
     if (value > 0)
         bl_fade_in_step = ((BL_PWM_INTERVAL*BL_PWM_COUNT)<<16) / value;
     else
         bl_fade_in_step = 0;
 }

 void backlight_set_fade_out(int value)
 {
     if (value > 0)
         bl_fade_out_step = ((BL_PWM_INTERVAL*BL_PWM_COUNT)<<16) / value;
     else
         bl_fade_out_step = 0;
 }
 #endif /* defined(HAVE_BACKLIGHT_PWM_FADING) && !defined(SIMULATOR) */

 /* Update state of backlight according to timeout setting */
 static void backlight_update_state(void)
 {
 #ifdef HAS_BUTTON_HOLD
     if ((backlight_on_button_hold != 0)
 #ifdef HAVE_REMOTE_LCD_AS_MAIN
         && remote_button_hold()
 #else
         && button_hold()
 #endif
         )
         backlight_timeout = (backlight_on_button_hold == 2) ? 0 : -1;
         /* always on or always off */
     else
 #endif
 #if CONFIG_CHARGING
         if (charger_inserted()
 #ifdef HAVE_USB_POWER
             || usb_powered()
 #endif
             )
             backlight_timeout = backlight_timeout_plugged;
         else
 #endif
             backlight_timeout = backlight_timeout_normal;

     /* Backlight == OFF in the setting? */
     if (backlight_timeout < 0)
     {
         backlight_timer = 0; /* Disable the timeout */
         _backlight_off();
     }
     else
     {
         backlight_timer = backlight_timeout;
         _backlight_on();
     }
 }

 #ifdef HAVE_REMOTE_LCD
 /* Update state of remote backlight according to timeout setting */
 static void remote_backlight_update_state(void)
 {
 #ifdef HAS_REMOTE_BUTTON_HOLD
     if (remote_button_hold() && (remote_backlight_on_button_hold != 0))
         remote_backlight_timeout = (remote_backlight_on_button_hold == 2)
                                  ? 0 : -1;  /* always on or always off */
     else
 #endif
 #if CONFIG_CHARGING
         if (charger_inserted()
 #ifdef HAVE_USB_POWER
             || usb_powered()
 #endif
             )
             remote_backlight_timeout = remote_backlight_timeout_plugged;
         else
 #endif
             remote_backlight_timeout = remote_backlight_timeout_normal;

     /* Backlight == OFF in the setting? */
     if (remote_backlight_timeout < 0)
     {
         remote_backlight_timer = 0; /* Disable the timeout */
         _remote_backlight_off();
     }
     else
     {
         remote_backlight_timer = remote_backlight_timeout;
         _remote_backlight_on();
     }
 }
 #endif /* HAVE_REMOTE_LCD */

 void backlight_thread(void)
 {
     struct queue_event ev;
     bool locked = false;

     while(1)
     {
         queue_wait(&backlight_queue, &ev);
         switch(ev.id)
         {   /* These events must always be processed */
 #ifdef _BACKLIGHT_FADE_BOOST
             case BACKLIGHT_FADE_FINISH:
                 cpu_boost(false);
                 break;
 #endif
 #ifdef _BACKLIGHT_FADE_ENABLE
             case BACKLIGHT_FADE_FINISH:
                 _backlight_hw_enable((bl_dim_current|bl_dim_target) != 0);
                 break;
 #endif

 #ifndef SIMULATOR
             /* Here for now or else the aggressive init messes up scrolling */
 #ifdef HAVE_REMOTE_LCD
             case SYS_REMOTE_PLUGGED:
                 lcd_remote_on();
                 lcd_remote_update();
                 break;

             case SYS_REMOTE_UNPLUGGED:
                 lcd_remote_off();
                 break;
 #elif defined HAVE_REMOTE_LCD_AS_MAIN
             case SYS_REMOTE_PLUGGED:
                 lcd_on();
                 lcd_update();
                 break;

             case SYS_REMOTE_UNPLUGGED:
                 lcd_off();
                 break;
 #endif /* HAVE_REMOTE_LCD/ HAVE_REMOTE_LCD_AS_MAIN */
 #endif /* !SIMULATOR */
 #ifdef SIMULATOR
             /* This one here too for lack of a better place */
             case SYS_SCREENDUMP:
                 screen_dump();
                 break;
 #endif
             case SYS_USB_CONNECTED:
                 /* Tell the USB thread that we are safe */
                 DEBUGF("backlight_thread got SYS_USB_CONNECTED\n");
                 usb_acknowledge(SYS_USB_CONNECTED_ACK);
                 break;

             case SYS_USB_DISCONNECTED:
                 usb_acknowledge(SYS_USB_DISCONNECTED_ACK);
                 break;

 #ifdef BACKLIGHT_DRIVER_CLOSE
             /* Get out of here */
             case BACKLIGHT_QUIT:
                 return;
 #endif
         }
         if (locked)
             continue;

         switch(ev.id)
         {   /* These events are only processed if backlight isn't locked */
 #ifdef HAVE_REMOTE_LCD
             case REMOTE_BACKLIGHT_ON:
                 remote_backlight_update_state();
                 break;

             case REMOTE_BACKLIGHT_OFF:
                 remote_backlight_timer = 0; /* Disable the timeout */
                 _remote_backlight_off();
                 break;
 #endif /* HAVE_REMOTE_LCD */

             case BACKLIGHT_ON:
                 backlight_update_state();
                 break;

             case BACKLIGHT_OFF:
                 backlight_timer = 0; /* Disable the timeout */
                 _backlight_off();
                 break;

 #ifdef HAVE_LCD_SLEEP
             case LCD_SLEEP:
                 lcd_sleep();
                 break;
 #endif
 #ifdef HAVE_BUTTON_LIGHT
             case BUTTON_LIGHT_ON:
                 buttonlight_update_state();
                 break;

             case BUTTON_LIGHT_OFF:
                 buttonlight_timer = 0;
                 _buttonlight_off();
                 break;
 #endif

             case SYS_POWEROFF:  /* Lock backlight on poweroff so it doesn't */
                 locked = true;      /* go off before power is actually cut. */
                 /* fall through */
 #if CONFIG_CHARGING
             case SYS_CHARGER_CONNECTED:
             case SYS_CHARGER_DISCONNECTED:
 #endif
                 backlight_update_state();
 #ifdef HAVE_REMOTE_LCD
                 remote_backlight_update_state();
 #endif
                 break;
         }
     } /* end while */
 }

 static void backlight_tick(void)
 {
     if(backlight_timer)
     {
         backlight_timer--;
         if(backlight_timer == 0)
         {
             backlight_off();
         }
     }
 #ifdef HAVE_LCD_SLEEP
     else if(lcd_sleep_timer)
     {
         lcd_sleep_timer--;
         if(lcd_sleep_timer == 0)
         {
             /* Queue on bl thread or freeze! */
             queue_post(&backlight_queue, LCD_SLEEP, 0);
         }
     }
 #endif /* HAVE_LCD_SLEEP */

 #ifdef HAVE_REMOTE_LCD
     if(remote_backlight_timer)
     {
         remote_backlight_timer--;
         if(remote_backlight_timer == 0)
         {
             remote_backlight_off();
         }
     }
 #endif /* HAVE_REMOVE_LCD */
 #ifdef HAVE_BUTTON_LIGHT
     if (buttonlight_timer)
     {
         buttonlight_timer--;
         if (buttonlight_timer == 0)
         {
             buttonlight_off();
         }
     }
 #endif /* HAVE_BUTTON_LIGHT */
 }

 void backlight_init(void)
 {
     queue_init(&backlight_queue, true);

 #ifndef SIMULATOR
     if (_backlight_init())
     {
 # ifdef HAVE_BACKLIGHT_PWM_FADING
         /* If backlight is already on, don't fade in. */
         bl_dim_target = BL_PWM_COUNT;
         bl_dim_fraction = (BL_PWM_COUNT<<16);
 # endif
     }
 #endif
     /* Leave all lights as set by the bootloader here. The settings load will
      * call the appropriate backlight_set_*() functions, only changing light
      * status if necessary. */
 #ifdef BACKLIGHT_DRIVER_CLOSE
     backlight_thread_p =
 #endif
     create_thread(backlight_thread, backlight_stack,
                   sizeof(backlight_stack), 0, backlight_thread_name
                   IF_PRIO(, PRIORITY_USER_INTERFACE)
                   IF_COP(, CPU));
     tick_add_task(backlight_tick);
 }

 #ifdef BACKLIGHT_DRIVER_CLOSE
 void backlight_close(void)
 {
     struct thread_entry *thread = backlight_thread_p;

     /* Wait for thread to exit */
     if (thread == NULL)
         return;

     backlight_thread_p = NULL;

     queue_post(&backlight_queue, BACKLIGHT_QUIT, 0);
     thread_wait(thread);
 }
 #endif /* BACKLIGHT_DRIVER_CLOSE */

 void backlight_on(void)
 {
     queue_remove_from_head(&backlight_queue, BACKLIGHT_ON);
     queue_post(&backlight_queue, BACKLIGHT_ON, 0);
 }

 void backlight_off(void)
 {
     queue_post(&backlight_queue, BACKLIGHT_OFF, 0);
 }

 /* returns true when the backlight is on,
  * and optionally when it's set to always off. */
 bool is_backlight_on(bool ignore_always_off)
 {
     return (backlight_timer > 0)   /* countdown */
         || (backlight_timeout == 0) /* always on */
         || ((backlight_timeout < 0) && !ignore_always_off);
 }

 /* return value in ticks; 0 means always on, <0 means always off */
 int backlight_get_current_timeout(void)
 {
     return backlight_timeout;
 }

 void backlight_set_timeout(int value)
 {
     backlight_timeout_normal = HZ * value;
     backlight_update_state();
 }

 #if CONFIG_CHARGING
 void backlight_set_timeout_plugged(int value)
 {
     backlight_timeout_plugged = HZ * value;
     backlight_update_state();
 }
 #endif /* CONFIG_CHARGING */

 #ifdef HAS_BUTTON_HOLD
 /* Hold button change event handler. */
 void backlight_hold_changed(bool hold_button)
 {
     if (!hold_button || (backlight_on_button_hold > 0))
         /* if unlocked or override in effect */
         backlight_on();
 }

 void backlight_set_on_button_hold(int index)
 {
     if ((unsigned)index >= 3)
         /* if given a weird value, use default */
         index = 0;

     backlight_on_button_hold = index;
     backlight_update_state();
 }
 #endif /* HAS_BUTTON_HOLD */

 #ifdef HAVE_LCD_SLEEP_SETTING
 void lcd_set_sleep_after_backlight_off(int index)
 {
     if ((unsigned)index >= sizeof(lcd_sleep_timeout_value))
         /* if given a weird value, use default */
         index = 3;

     lcd_sleep_timeout = HZ * lcd_sleep_timeout_value[index];

     if (backlight_timer > 0 || backlight_get_current_timeout() == 0)
         /* Timer will be set when bl turns off or bl set to on. */
         return;

     /* Backlight is Off */
     if (lcd_sleep_timeout < 0)
         lcd_sleep_timer = 1; /* Always - sleep next tick */
     else
         lcd_sleep_timer = lcd_sleep_timeout; /* Never, other */
 }
 #endif /* HAVE_LCD_SLEEP_SETTING */

 #ifdef HAVE_REMOTE_LCD
 void remote_backlight_on(void)
 {
     queue_post(&backlight_queue, REMOTE_BACKLIGHT_ON, 0);
 }

 void remote_backlight_off(void)
 {
     queue_post(&backlight_queue, REMOTE_BACKLIGHT_OFF, 0);
 }

 void remote_backlight_set_timeout(int value)
 {
     remote_backlight_timeout_normal = HZ * value;
     remote_backlight_update_state();
 }

 #if CONFIG_CHARGING
 void remote_backlight_set_timeout_plugged(int value)
 {
     remote_backlight_timeout_plugged = HZ * value;
     remote_backlight_update_state();
 }
 #endif /* CONFIG_CHARGING */

 #ifdef HAS_REMOTE_BUTTON_HOLD
 /* Remote hold button change event handler. */
 void remote_backlight_hold_changed(bool rc_hold_button)
 {
     if (!rc_hold_button || (remote_backlight_on_button_hold > 0))
         /* if unlocked or override */
         remote_backlight_on();
 }

 void remote_backlight_set_on_button_hold(int index)
 {
     if ((unsigned)index >= 3)
         /* if given a weird value, use default */
         index = 0;

     remote_backlight_on_button_hold = index;
     remote_backlight_update_state();
 }
 #endif /* HAS_REMOTE_BUTTON_HOLD */

 /* return value in ticks; 0 means always on, <0 means always off */
 int remote_backlight_get_current_timeout(void)
 {
     return remote_backlight_timeout;
 }

 /* returns true when the backlight is on, and
  * optionally  when it's set to always off */
 bool is_remote_backlight_on(bool ignore_always_off)
 {
     return (remote_backlight_timer > 0)   /* countdown */
         || (remote_backlight_timeout == 0) /* always on */
         || ((remote_backlight_timeout < 0) && !ignore_always_off);
 }

 #endif /* HAVE_REMOTE_LCD */

 #ifdef HAVE_BACKLIGHT_BRIGHTNESS
 void backlight_set_brightness(int val)
 {
     if (val < MIN_BRIGHTNESS_SETTING)
         val = MIN_BRIGHTNESS_SETTING;
     else if (val > MAX_BRIGHTNESS_SETTING)
         val = MAX_BRIGHTNESS_SETTING;

     _backlight_set_brightness(val);
 }
 #endif /* HAVE_BACKLIGHT_BRIGHTNESS */

 #ifdef HAVE_BUTTONLIGHT_BRIGHTNESS
 void buttonlight_set_brightness(int val)
 {
     if (val < MIN_BRIGHTNESS_SETTING)
         val = MIN_BRIGHTNESS_SETTING;
     else if (val > MAX_BRIGHTNESS_SETTING)
         val = MAX_BRIGHTNESS_SETTING;

     _buttonlight_set_brightness(val);
 }
 #endif /* HAVE_BUTTONLIGHT_BRIGHTNESS */

 #else /* !defined(HAVE_BACKLIGHT) || !defined(BACKLIGHT_FULL_INIT)
     -- no backlight, empty dummy functions */

 #if defined(HAVE_BACKLIGHT) && !defined(BACKLIGHT_FULL_INIT)
 void backlight_init(void)
 {
     (void)_backlight_init();
     _backlight_on();
 }
 #endif

 void backlight_on(void) {}
 void backlight_off(void) {}
 void buttonlight_on(void) {}
 void backlight_set_timeout(int value) {(void)value;}

 bool is_backlight_on(bool ignore_always_off)
 {
     (void)ignore_always_off;
     return true;
 }
 #ifdef HAVE_REMOTE_LCD
 void remote_backlight_on(void) {}
 void remote_backlight_off(void) {}
 void remote_backlight_set_timeout(int value) {(void)value;}

 bool is_remote_backlight_on(bool ignore_always_off)
 {
     (void)ignore_always_off;
     return true;
 }
 #endif /* HAVE_REMOTE_LCD */
 #ifdef HAVE_BACKLIGHT_BRIGHTNESS
 void backlight_set_brightness(int val) { (void)val; }
 #endif
 #ifdef HAVE_BUTTONLIGHT_BRIGHTNESS
 void buttonlight_set_brightness(int val) { (void)val; }
 #endif
 #endif /* defined(HAVE_BACKLIGHT) && defined(BACKLIGHT_FULL_INIT) */
	/***************************************************************************
	* __________ __ ___.
	* Open \______ \ ____ ____ \| \| _\_ \|__ _______ ___
	* Source \| _// _ \_/ ___\\| \|/ /\| __ \ / _ \ \/ /
	* Jukebox \| \| ( <_> ) \___\| < \| \_\ ( <_> > < <
	* Firmware \|____\|_ /\____/ \___ >__\|_ \\|___ /\____/__/\_ \
	* \/ \/ \/ \/ \/
	* $Id$
	*
	* Copyright (C) 2002 by Linus Nielsen Feltzing
	*
	* 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 <stdlib.h>
	#include "cpu.h"
	#include "kernel.h"
	#include "thread.h"
	#include "i2c.h"
	#include "debug.h"
	#include "rtc.h"
	#include "usb.h"
	#include "power.h"
	#include "system.h"
	#include "button.h"
	#include "timer.h"
	#include "backlight.h"
	#include "lcd.h"

	#ifdef HAVE_REMOTE_LCD
	#include "lcd-remote.h"
	#endif
	#ifndef SIMULATOR
	#include "backlight-target.h"
	#endif

	#if !defined(BOOTLOADER)
	/* The whole driver should be built */
	#define BACKLIGHT_FULL_INIT
	#endif

	#ifdef SIMULATOR
	/* TODO: find a better way to do it but we need a kernel thread somewhere to
	handle this */
	extern void screen_dump(void);

	static inline void _backlight_on(void)
	{
	sim_backlight(100);
	}

	static inline void _backlight_off(void)
	{
	sim_backlight(0);
	}

	static inline void _backlight_set_brightness(int val)
	{
	(void)val;
	}

	static inline void _buttonlight_on(void)
	{
	}

	static inline void _buttonlight_off(void)
	{
	}

	static inline void _buttonlight_set_brightness(int val)
	{
	(void)val;
	}
	#ifdef HAVE_REMOTE_LCD
	static inline void _remote_backlight_on(void)
	{
	sim_remote_backlight(100);
	}

	static inline void _remote_backlight_off(void)
	{
	sim_remote_backlight(0);
	}
	#endif /* HAVE_REMOTE_LCD */

	#endif /* SIMULATOR */

	#if defined(HAVE_BACKLIGHT) && defined(BACKLIGHT_FULL_INIT)

	enum {
	BACKLIGHT_ON,
	BACKLIGHT_OFF,
	#ifdef HAVE_REMOTE_LCD
	REMOTE_BACKLIGHT_ON,
	REMOTE_BACKLIGHT_OFF,
	#endif
	#if defined(_BACKLIGHT_FADE_BOOST) \|\| defined(_BACKLIGHT_FADE_ENABLE)
	BACKLIGHT_FADE_FINISH,
	#endif
	#ifdef HAVE_LCD_SLEEP
	LCD_SLEEP,
	#endif
	#ifdef HAVE_BUTTON_LIGHT
	BUTTON_LIGHT_ON,
	BUTTON_LIGHT_OFF,
	#endif
	#ifdef BACKLIGHT_DRIVER_CLOSE
	BACKLIGHT_QUIT,
	#endif
	};

	static void backlight_thread(void);
	static long backlight_stack[DEFAULT_STACK_SIZE/sizeof(long)];
	static const char backlight_thread_name[] = "backlight";
	static struct event_queue backlight_queue;
	#ifdef BACKLIGHT_DRIVER_CLOSE
	static struct thread_entry *backlight_thread_p = NULL;
	#endif

	static int backlight_timer SHAREDBSS_ATTR;
	static int backlight_timeout SHAREDBSS_ATTR;
	static int backlight_timeout_normal = 5*HZ;
	#if CONFIG_CHARGING
	static int backlight_timeout_plugged = 5*HZ;
	#endif
	#ifdef HAS_BUTTON_HOLD
	static int backlight_on_button_hold = 0;
	#endif

	#ifdef HAVE_BUTTON_LIGHT
	static int buttonlight_timer;
	int _buttonlight_timeout = 5*HZ;

	/* Update state of buttonlight according to timeout setting */
	static void buttonlight_update_state(void)
	{
	buttonlight_timer = _buttonlight_timeout;

	/* Buttonlight == OFF in the setting? */
	if (buttonlight_timer < 0)
	{
	buttonlight_timer = 0; /* Disable the timeout */
	_buttonlight_off();
	}
	else
	_buttonlight_on();
	}

	/* external interface */
	void buttonlight_on(void)
	{
	queue_remove_from_head(&backlight_queue, BUTTON_LIGHT_ON);
	queue_post(&backlight_queue, BUTTON_LIGHT_ON, 0);
	}

	void buttonlight_off(void)
	{
	queue_post(&backlight_queue, BUTTON_LIGHT_OFF, 0);
	}

	void buttonlight_set_timeout(int value)
	{
	_buttonlight_timeout = HZ * value;
	buttonlight_update_state();
	}

	#endif /* HAVE_BUTTON_LIGHT */

	#ifdef HAVE_REMOTE_LCD
	static int remote_backlight_timer;
	static int remote_backlight_timeout;
	static int remote_backlight_timeout_normal = 5*HZ;
	#if CONFIG_CHARGING
	static int remote_backlight_timeout_plugged = 5*HZ;
	#endif
	#ifdef HAS_REMOTE_BUTTON_HOLD
	static int remote_backlight_on_button_hold = 0;
	#endif
	#endif /* HAVE_REMOTE_LCD */

	#ifdef HAVE_LCD_SLEEP
	#ifdef HAVE_LCD_SLEEP_SETTING
	const signed char lcd_sleep_timeout_value[10] =
	{
	-1, 0, 5, 10, 15, 20, 30, 45, 60, 90
	};
	static int lcd_sleep_timeout = 10*HZ;
	#else
	/* Target defines needed value */
	static const int lcd_sleep_timeout = LCD_SLEEP_TIMEOUT;
	#endif

	static int lcd_sleep_timer = 0;

	void backlight_lcd_sleep_countdown(bool start)
	{
	if (!start)
	{
	/* Cancel the LCD sleep countdown */
	lcd_sleep_timer = 0;
	return;
	}

	/* Start LCD sleep countdown */
	if (lcd_sleep_timeout < 0)
	{
	lcd_sleep_timer = 0; /* Setting == Always */
	lcd_sleep();
	}
	else
	{
	lcd_sleep_timer = lcd_sleep_timeout;
	}
	}
	#endif /* HAVE_LCD_SLEEP */

	#if defined(HAVE_BACKLIGHT_PWM_FADING) && !defined(SIMULATOR)
	/* backlight fading */
	#define BL_PWM_INTERVAL 5 /* Cycle interval in ms */
	#define BL_PWM_BITS 8
	#define BL_PWM_COUNT (1<<BL_PWM_BITS)

	/* s15.16 fixed point variables */
	static int32_t bl_fade_in_step = ((BL_PWM_INTERVAL*BL_PWM_COUNT)<<16)/300;
	static int32_t bl_fade_out_step = ((BL_PWM_INTERVAL*BL_PWM_COUNT)<<16)/2000;
	static int32_t bl_dim_fraction = 0;

	static int bl_dim_target = 0;
	static int bl_dim_current = 0;
	static enum {DIM_STATE_START, DIM_STATE_MAIN} bl_dim_state = DIM_STATE_START;
	static bool bl_timer_active = false;

	static void backlight_isr(void)
	{
	int timer_period = (TIMER_FREQ*BL_PWM_INTERVAL/1000);
	bool idle = false;

	switch (bl_dim_state)
	{
	/* New cycle */
	case DIM_STATE_START:
	bl_dim_current = bl_dim_fraction >> 16;

	if (bl_dim_current > 0 && bl_dim_current < BL_PWM_COUNT)
	{
	_backlight_on_isr();
	timer_period = (timer_period * bl_dim_current) >> BL_PWM_BITS;
	bl_dim_state = DIM_STATE_MAIN;
	}
	else
	{
	if (bl_dim_current)
	_backlight_on_isr();
	else
	_backlight_off_isr();
	if (bl_dim_current == bl_dim_target)
	idle = true;
	}
	if (bl_dim_current < bl_dim_target)
	{
	bl_dim_fraction = MIN(bl_dim_fraction + bl_fade_in_step,
	(BL_PWM_COUNT<<16));
	}
	else if (bl_dim_current > bl_dim_target)
	{
	bl_dim_fraction = MAX(bl_dim_fraction - bl_fade_out_step, 0);
	}
	break;

	/* Dim main screen */
	case DIM_STATE_MAIN:
	_backlight_off_isr();
	timer_period = (timer_period * (BL_PWM_COUNT - bl_dim_current))
	>> BL_PWM_BITS;
	bl_dim_state = DIM_STATE_START;
	break ;
	}
	if (idle)
	{
	#if defined(_BACKLIGHT_FADE_BOOST) \|\| defined(_BACKLIGHT_FADE_ENABLE)
	queue_post(&backlight_queue, BACKLIGHT_FADE_FINISH, 0);
	#endif
	timer_unregister();
	bl_timer_active = false;
	}
	else
	timer_set_period(timer_period);
	}

	static void backlight_switch(void)
	{
	if (bl_dim_target > (BL_PWM_COUNT/2))
	{
	_backlight_on_normal();
	bl_dim_fraction = (BL_PWM_COUNT<<16);
	}
	else
	{
	_backlight_off_normal();
	bl_dim_fraction = 0;
	}
	}

	static void backlight_release_timer(void)
	{
	#ifdef _BACKLIGHT_FADE_BOOST
	cpu_boost(false);
	#endif
	timer_unregister();
	bl_timer_active = false;
	backlight_switch();
	}

	static void backlight_dim(int value)
	{
	/* protect from extraneous calls with the same target value */
	if (value == bl_dim_target)
	return;

	bl_dim_target = value;

	if (bl_timer_active)
	return ;

	if (timer_register(0, backlight_release_timer, 2, 0, backlight_isr
	IF_COP(, CPU)))
	{
	#ifdef _BACKLIGHT_FADE_BOOST
	/* Prevent cpu frequency changes while dimming. */
	cpu_boost(true);
	#endif
	bl_timer_active = true;
	}
	else
	backlight_switch();
	}

	static void _backlight_on(void)
	{
	#ifdef HAVE_LCD_SLEEP
	backlight_lcd_sleep_countdown(false);
	#endif

	if (bl_fade_in_step > 0)
	{
	#ifdef _BACKLIGHT_FADE_ENABLE
	_backlight_hw_enable(true);
	#endif
	backlight_dim(BL_PWM_COUNT);
	}
	else
	{
	bl_dim_target = BL_PWM_COUNT;
	bl_dim_fraction = (BL_PWM_COUNT<<16);
	_backlight_on_normal();
	}
	}

	static void _backlight_off(void)
	{
	if (bl_fade_out_step > 0)
	{
	backlight_dim(0);
	}
	else
	{
	bl_dim_target = bl_dim_fraction = 0;
	_backlight_off_normal();
	}

	#ifdef HAVE_LCD_SLEEP
	backlight_lcd_sleep_countdown(true);
	#endif
	}

	void backlight_set_fade_in(int value)
	{
	if (value > 0)
	bl_fade_in_step = ((BL_PWM_INTERVAL*BL_PWM_COUNT)<<16) / value;
	else
	bl_fade_in_step = 0;
	}

	void backlight_set_fade_out(int value)
	{
	if (value > 0)
	bl_fade_out_step = ((BL_PWM_INTERVAL*BL_PWM_COUNT)<<16) / value;
	else
	bl_fade_out_step = 0;
	}
	#endif /* defined(HAVE_BACKLIGHT_PWM_FADING) && !defined(SIMULATOR) */

	/* Update state of backlight according to timeout setting */
	static void backlight_update_state(void)
	{
	#ifdef HAS_BUTTON_HOLD
	if ((backlight_on_button_hold != 0)
	#ifdef HAVE_REMOTE_LCD_AS_MAIN
	&& remote_button_hold()
	#else
	&& button_hold()
	#endif
	)
	backlight_timeout = (backlight_on_button_hold == 2) ? 0 : -1;
	/* always on or always off */
	else
	#endif
	#if CONFIG_CHARGING
	if (charger_inserted()
	#ifdef HAVE_USB_POWER
	\|\| usb_powered()
	#endif
	)
	backlight_timeout = backlight_timeout_plugged;
	else
	#endif
	backlight_timeout = backlight_timeout_normal;

	/* Backlight == OFF in the setting? */
	if (backlight_timeout < 0)
	{
	backlight_timer = 0; /* Disable the timeout */
	_backlight_off();
	}
	else
	{
	backlight_timer = backlight_timeout;
	_backlight_on();
	}
	}

	#ifdef HAVE_REMOTE_LCD
	/* Update state of remote backlight according to timeout setting */
	static void remote_backlight_update_state(void)
	{
	#ifdef HAS_REMOTE_BUTTON_HOLD
	if (remote_button_hold() && (remote_backlight_on_button_hold != 0))
	remote_backlight_timeout = (remote_backlight_on_button_hold == 2)
	? 0 : -1; /* always on or always off */
	else
	#endif
	#if CONFIG_CHARGING
	if (charger_inserted()
	#ifdef HAVE_USB_POWER
	\|\| usb_powered()
	#endif
	)
	remote_backlight_timeout = remote_backlight_timeout_plugged;
	else
	#endif
	remote_backlight_timeout = remote_backlight_timeout_normal;

	/* Backlight == OFF in the setting? */
	if (remote_backlight_timeout < 0)
	{
	remote_backlight_timer = 0; /* Disable the timeout */
	_remote_backlight_off();
	}
	else
	{
	remote_backlight_timer = remote_backlight_timeout;
	_remote_backlight_on();
	}
	}
	#endif /* HAVE_REMOTE_LCD */

	void backlight_thread(void)
	{
	struct queue_event ev;
	bool locked = false;

	while(1)
	{
	queue_wait(&backlight_queue, &ev);
	switch(ev.id)
	{ /* These events must always be processed */
	#ifdef _BACKLIGHT_FADE_BOOST
	case BACKLIGHT_FADE_FINISH:
	cpu_boost(false);
	break;
	#endif
	#ifdef _BACKLIGHT_FADE_ENABLE
	case BACKLIGHT_FADE_FINISH:
	_backlight_hw_enable((bl_dim_current\|bl_dim_target) != 0);
	break;
	#endif

	#ifndef SIMULATOR
	/* Here for now or else the aggressive init messes up scrolling */
	#ifdef HAVE_REMOTE_LCD
	case SYS_REMOTE_PLUGGED:
	lcd_remote_on();
	lcd_remote_update();
	break;

	case SYS_REMOTE_UNPLUGGED:
	lcd_remote_off();
	break;
	#elif defined HAVE_REMOTE_LCD_AS_MAIN
	case SYS_REMOTE_PLUGGED:
	lcd_on();
	lcd_update();
	break;

	case SYS_REMOTE_UNPLUGGED:
	lcd_off();
	break;
	#endif /* HAVE_REMOTE_LCD/ HAVE_REMOTE_LCD_AS_MAIN */
	#endif /* !SIMULATOR */
	#ifdef SIMULATOR
	/* This one here too for lack of a better place */
	case SYS_SCREENDUMP:
	screen_dump();
	break;
	#endif
	case SYS_USB_CONNECTED:
	/* Tell the USB thread that we are safe */
	DEBUGF("backlight_thread got SYS_USB_CONNECTED\n");
	usb_acknowledge(SYS_USB_CONNECTED_ACK);
	break;

	case SYS_USB_DISCONNECTED:
	usb_acknowledge(SYS_USB_DISCONNECTED_ACK);
	break;

	#ifdef BACKLIGHT_DRIVER_CLOSE
	/* Get out of here */
	case BACKLIGHT_QUIT:
	return;
	#endif
	}
	if (locked)
	continue;

	switch(ev.id)
	{ /* These events are only processed if backlight isn't locked */
	#ifdef HAVE_REMOTE_LCD
	case REMOTE_BACKLIGHT_ON:
	remote_backlight_update_state();
	break;

	case REMOTE_BACKLIGHT_OFF:
	remote_backlight_timer = 0; /* Disable the timeout */
	_remote_backlight_off();
	break;
	#endif /* HAVE_REMOTE_LCD */

	case BACKLIGHT_ON:
	backlight_update_state();
	break;

	case BACKLIGHT_OFF:
	backlight_timer = 0; /* Disable the timeout */
	_backlight_off();
	break;

	#ifdef HAVE_LCD_SLEEP
	case LCD_SLEEP:
	lcd_sleep();
	break;
	#endif
	#ifdef HAVE_BUTTON_LIGHT
	case BUTTON_LIGHT_ON:
	buttonlight_update_state();
	break;

	case BUTTON_LIGHT_OFF:
	buttonlight_timer = 0;
	_buttonlight_off();
	break;
	#endif

	case SYS_POWEROFF: /* Lock backlight on poweroff so it doesn't */
	locked = true; /* go off before power is actually cut. */
	/* fall through */
	#if CONFIG_CHARGING
	case SYS_CHARGER_CONNECTED:
	case SYS_CHARGER_DISCONNECTED:
	#endif
	backlight_update_state();
	#ifdef HAVE_REMOTE_LCD
	remote_backlight_update_state();
	#endif
	break;
	}
	} /* end while */
	}

	static void backlight_tick(void)
	{
	if(backlight_timer)
	{
	backlight_timer--;
	if(backlight_timer == 0)
	{
	backlight_off();
	}
	}
	#ifdef HAVE_LCD_SLEEP
	else if(lcd_sleep_timer)
	{
	lcd_sleep_timer--;
	if(lcd_sleep_timer == 0)
	{
	/* Queue on bl thread or freeze! */
	queue_post(&backlight_queue, LCD_SLEEP, 0);
	}
	}
	#endif /* HAVE_LCD_SLEEP */

	#ifdef HAVE_REMOTE_LCD
	if(remote_backlight_timer)
	{
	remote_backlight_timer--;
	if(remote_backlight_timer == 0)
	{
	remote_backlight_off();
	}
	}
	#endif /* HAVE_REMOVE_LCD */
	#ifdef HAVE_BUTTON_LIGHT
	if (buttonlight_timer)
	{
	buttonlight_timer--;
	if (buttonlight_timer == 0)
	{
	buttonlight_off();
	}
	}
	#endif /* HAVE_BUTTON_LIGHT */
	}

	void backlight_init(void)
	{
	queue_init(&backlight_queue, true);

	#ifndef SIMULATOR
	if (_backlight_init())
	{
	# ifdef HAVE_BACKLIGHT_PWM_FADING
	/* If backlight is already on, don't fade in. */
	bl_dim_target = BL_PWM_COUNT;
	bl_dim_fraction = (BL_PWM_COUNT<<16);
	# endif
	}
	#endif
	/* Leave all lights as set by the bootloader here. The settings load will
	* call the appropriate backlight_set_*() functions, only changing light
	* status if necessary. */
	#ifdef BACKLIGHT_DRIVER_CLOSE
	backlight_thread_p =
	#endif
	create_thread(backlight_thread, backlight_stack,
	sizeof(backlight_stack), 0, backlight_thread_name
	IF_PRIO(, PRIORITY_USER_INTERFACE)
	IF_COP(, CPU));
	tick_add_task(backlight_tick);
	}

	#ifdef BACKLIGHT_DRIVER_CLOSE
	void backlight_close(void)
	{
	struct thread_entry *thread = backlight_thread_p;

	/* Wait for thread to exit */
	if (thread == NULL)
	return;

	backlight_thread_p = NULL;

	queue_post(&backlight_queue, BACKLIGHT_QUIT, 0);
	thread_wait(thread);
	}
	#endif /* BACKLIGHT_DRIVER_CLOSE */

	void backlight_on(void)
	{
	queue_remove_from_head(&backlight_queue, BACKLIGHT_ON);
	queue_post(&backlight_queue, BACKLIGHT_ON, 0);
	}

	void backlight_off(void)
	{
	queue_post(&backlight_queue, BACKLIGHT_OFF, 0);
	}

	/* returns true when the backlight is on,
	* and optionally when it's set to always off. */
	bool is_backlight_on(bool ignore_always_off)
	{
	return (backlight_timer > 0) /* countdown */
	\|\| (backlight_timeout == 0) /* always on */
	\|\| ((backlight_timeout < 0) && !ignore_always_off);
	}

	/* return value in ticks; 0 means always on, <0 means always off */
	int backlight_get_current_timeout(void)
	{
	return backlight_timeout;
	}

	void backlight_set_timeout(int value)
	{
	backlight_timeout_normal = HZ * value;
	backlight_update_state();
	}

	#if CONFIG_CHARGING
	void backlight_set_timeout_plugged(int value)
	{
	backlight_timeout_plugged = HZ * value;
	backlight_update_state();
	}
	#endif /* CONFIG_CHARGING */

	#ifdef HAS_BUTTON_HOLD
	/* Hold button change event handler. */
	void backlight_hold_changed(bool hold_button)
	{
	if (!hold_button \|\| (backlight_on_button_hold > 0))
	/* if unlocked or override in effect */
	backlight_on();
	}

	void backlight_set_on_button_hold(int index)
	{
	if ((unsigned)index >= 3)
	/* if given a weird value, use default */
	index = 0;

	backlight_on_button_hold = index;
	backlight_update_state();
	}
	#endif /* HAS_BUTTON_HOLD */

	#ifdef HAVE_LCD_SLEEP_SETTING
	void lcd_set_sleep_after_backlight_off(int index)
	{
	if ((unsigned)index >= sizeof(lcd_sleep_timeout_value))
	/* if given a weird value, use default */
	index = 3;

	lcd_sleep_timeout = HZ * lcd_sleep_timeout_value[index];

	if (backlight_timer > 0 \|\| backlight_get_current_timeout() == 0)
	/* Timer will be set when bl turns off or bl set to on. */
	return;

	/* Backlight is Off */
	if (lcd_sleep_timeout < 0)
	lcd_sleep_timer = 1; /* Always - sleep next tick */
	else
	lcd_sleep_timer = lcd_sleep_timeout; /* Never, other */
	}
	#endif /* HAVE_LCD_SLEEP_SETTING */

	#ifdef HAVE_REMOTE_LCD
	void remote_backlight_on(void)
	{
	queue_post(&backlight_queue, REMOTE_BACKLIGHT_ON, 0);
	}

	void remote_backlight_off(void)
	{
	queue_post(&backlight_queue, REMOTE_BACKLIGHT_OFF, 0);
	}

	void remote_backlight_set_timeout(int value)
	{
	remote_backlight_timeout_normal = HZ * value;
	remote_backlight_update_state();
	}

	#if CONFIG_CHARGING
	void remote_backlight_set_timeout_plugged(int value)
	{
	remote_backlight_timeout_plugged = HZ * value;
	remote_backlight_update_state();
	}
	#endif /* CONFIG_CHARGING */

	#ifdef HAS_REMOTE_BUTTON_HOLD
	/* Remote hold button change event handler. */
	void remote_backlight_hold_changed(bool rc_hold_button)
	{
	if (!rc_hold_button \|\| (remote_backlight_on_button_hold > 0))
	/* if unlocked or override */
	remote_backlight_on();
	}

	void remote_backlight_set_on_button_hold(int index)
	{
	if ((unsigned)index >= 3)
	/* if given a weird value, use default */
	index = 0;

	remote_backlight_on_button_hold = index;
	remote_backlight_update_state();
	}
	#endif /* HAS_REMOTE_BUTTON_HOLD */

	/* return value in ticks; 0 means always on, <0 means always off */
	int remote_backlight_get_current_timeout(void)
	{
	return remote_backlight_timeout;
	}

	/* returns true when the backlight is on, and
	* optionally when it's set to always off */
	bool is_remote_backlight_on(bool ignore_always_off)
	{
	return (remote_backlight_timer > 0) /* countdown */
	\|\| (remote_backlight_timeout == 0) /* always on */
	\|\| ((remote_backlight_timeout < 0) && !ignore_always_off);
	}

	#endif /* HAVE_REMOTE_LCD */

	#ifdef HAVE_BACKLIGHT_BRIGHTNESS
	void backlight_set_brightness(int val)
	{
	if (val < MIN_BRIGHTNESS_SETTING)
	val = MIN_BRIGHTNESS_SETTING;
	else if (val > MAX_BRIGHTNESS_SETTING)
	val = MAX_BRIGHTNESS_SETTING;

	_backlight_set_brightness(val);
	}
	#endif /* HAVE_BACKLIGHT_BRIGHTNESS */

	#ifdef HAVE_BUTTONLIGHT_BRIGHTNESS
	void buttonlight_set_brightness(int val)
	{
	if (val < MIN_BRIGHTNESS_SETTING)
	val = MIN_BRIGHTNESS_SETTING;
	else if (val > MAX_BRIGHTNESS_SETTING)
	val = MAX_BRIGHTNESS_SETTING;

	_buttonlight_set_brightness(val);
	}
	#endif /* HAVE_BUTTONLIGHT_BRIGHTNESS */

	#else /* !defined(HAVE_BACKLIGHT) \|\| !defined(BACKLIGHT_FULL_INIT)
	-- no backlight, empty dummy functions */

	#if defined(HAVE_BACKLIGHT) && !defined(BACKLIGHT_FULL_INIT)
	void backlight_init(void)
	{
	(void)_backlight_init();
	_backlight_on();
	}
	#endif

	void backlight_on(void) {}
	void backlight_off(void) {}
	void buttonlight_on(void) {}
	void backlight_set_timeout(int value) {(void)value;}

	bool is_backlight_on(bool ignore_always_off)
	{
	(void)ignore_always_off;
	return true;
	}
	#ifdef HAVE_REMOTE_LCD
	void remote_backlight_on(void) {}
	void remote_backlight_off(void) {}
	void remote_backlight_set_timeout(int value) {(void)value;}

	bool is_remote_backlight_on(bool ignore_always_off)
	{
	(void)ignore_always_off;
	return true;
	}
	#endif /* HAVE_REMOTE_LCD */
	#ifdef HAVE_BACKLIGHT_BRIGHTNESS
	void backlight_set_brightness(int val) { (void)val; }
	#endif
	#ifdef HAVE_BUTTONLIGHT_BRIGHTNESS
	void buttonlight_set_brightness(int val) { (void)val; }
	#endif
	#endif /* defined(HAVE_BACKLIGHT) && defined(BACKLIGHT_FULL_INIT) */