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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2008 by Maurus Cuelenaere
*
* 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 "jz4740.h"
#include "backlight-target.h"
/* PWM_CHN7 == GPIO(32*3 + 31) */
#define BACKLIGHT_GPIO (32*3+31)
#define BACKLIGHT_PWM 7
/* PWM counter (PWM INITL = 0):
* [0, PWM half rate[ -> backlight off
* [PWM half rate, PWM full rate[ -> backlight on
* [PWM full rate, PWM full rate] -> counter reset to 0
*/
static int old_val = MAX_BRIGHTNESS_SETTING;
static const unsigned char logtable[] = {255, 254, 253, 252, 250, 248, 245, 240, 233, 224, 211, 192, 165, 128, 75, 0};
static void set_backlight(int val)
{
if(val == old_val)
return;
/* Clock = 32 768 Hz */
__tcu_disable_pwm_output(BACKLIGHT_PWM);
__tcu_stop_counter(BACKLIGHT_PWM);
__tcu_set_count(BACKLIGHT_PWM, 0);
__tcu_set_half_data(BACKLIGHT_PWM, logtable[val - 1]);
__tcu_set_full_data(BACKLIGHT_PWM, 256);
__tcu_start_counter(BACKLIGHT_PWM);
__tcu_enable_pwm_output(BACKLIGHT_PWM);
old_val = val;
}
static void set_backlight_on(void)
{
__tcu_start_counter(BACKLIGHT_PWM);
__tcu_enable_pwm_output(BACKLIGHT_PWM);
}
static void set_backlight_off(void)
{
__tcu_disable_pwm_output(BACKLIGHT_PWM);
__tcu_stop_counter(BACKLIGHT_PWM);
}
bool _backlight_init(void)
{
__gpio_as_pwm(BACKLIGHT_PWM);
__tcu_start_timer_clock(BACKLIGHT_PWM);
__tcu_stop_counter(BACKLIGHT_PWM);
__tcu_init_pwm_output_low(BACKLIGHT_PWM);
__tcu_set_pwm_output_shutdown_graceful(BACKLIGHT_PWM);
__tcu_disable_pwm_output(BACKLIGHT_PWM);
__tcu_select_rtcclk(BACKLIGHT_PWM); /* 32.768 kHz */
__tcu_select_clk_div1(BACKLIGHT_PWM);
__tcu_mask_half_match_irq(BACKLIGHT_PWM);
__tcu_mask_full_match_irq(BACKLIGHT_PWM);
__tcu_set_count(BACKLIGHT_PWM, 0);
__tcu_set_half_data(BACKLIGHT_PWM, 0);
__tcu_set_full_data(BACKLIGHT_PWM, 256);
return true;
}
void _backlight_on(void)
{
set_backlight_on();
}
void _backlight_off(void)
{
set_backlight_off();
}
#ifdef HAVE_BACKLIGHT_BRIGHTNESS
void _backlight_set_brightness(int brightness)
{
set_backlight(brightness);
}
#endif
#ifdef HAVE_LCD_SLEEP
/* Turn off LED supply */
void _backlight_lcd_sleep(void)
{
set_backlight_off();
}
#endif
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