rockbox/firmware/target/arm/rk27xx/backlight-rk27xx.c
Marcin Bukat cad91ed938 rk27xx - fix backlight driver - now one can set brightness
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30138 a1c6a512-1295-4272-9138-f99709370657
2011-07-14 17:06:44 +00:00

92 lines
2.7 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2011 by Marcin Bukat
*
* 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 <stdbool.h>
#include "config.h"
#include "backlight.h"
#include "backlight-target.h"
#include "system.h"
static int brightness = DEFAULT_BRIGHTNESS_SETTING;
static const unsigned short log_brightness[] = {
0x2710, 0x27ac, 0x2849, 0x2983, 0x2abd, 0x2c93, 0x2e6a, 0x30dd,
0x3351, 0x3661, 0x3971, 0x3d1f, 0x40cc, 0x4516, 0x4960, 0x4e47,
0x532e, 0x58b1, 0x5e35, 0x6456, 0x6a76, 0x7134, 0x77f1, 0x7f4c,
0x86a6, 0x8e9d, 0x9695, 0x9f29, 0xa7bd, 0xb0ee, 0xba1f, 0xc350
};
bool _backlight_init(void)
{
/* configure PD4 as output */
GPIO_PDCON |= (1<<4);
/* set PD4 low (backlight off) */
GPIO_PDDR &= ~(1<<4);
/* IOMUXB - set PWM0 pin as GPIO */
SCU_IOMUXB_CON &= ~(1 << 11); /* type<<11<<channel */
/* DIV/2, PWM reset */
PWMT0_CTRL = (0<<9) | (1<<7);
/* set pwm frequency to 500Hz - my lcd panel can't cope more reliably */
/* (apb_freq/pwm_freq)/pwm_div = (50 000 000/500)/2 */
PWMT0_LRC = 50000;
PWMT0_HRC = log_brightness[brightness];
/* reset counter */
PWMT0_CNTR = 0x00;
/* DIV/2, PWM output enable, PWM timer enable */
PWMT0_CTRL = (0<<9) | (1<<3) | (1<<0);
return true;
}
void _backlight_on(void)
{
/* enable PWM clock */
SCU_CLKCFG &= ~(1<<29);
/* set output pin as PWM pin */
SCU_IOMUXB_CON |= (1<<11); /* type<<11<<channel */
/* pwm enable */
PWMT0_CTRL |= (1<<3) | (1<<0);
}
void _backlight_off(void)
{
/* setup PWM0 pin as GPIO which is pulled low */
SCU_IOMUXB_CON &= ~(1<<11);
/* stop pwm timer */
PWMT0_CTRL &= ~(1<<3) | (1<<0);
/* disable PWM clock */
SCU_CLKCFG |= (1<<29);
}
void _backlight_set_brightness(int val)
{
brightness = val & 0x1f;
PWMT0_HRC = log_brightness[brightness];
}