rockbox/firmware/target/arm/s5l8700/yps3/backlight-yps3.c
Marcin Bukat 89ba7e818c Get rid of stupid _backlight_* function names
_remote_backlight_* and _buttonlight_* are cleaned as well

Change-Id: I73653752831bbe170c26ba95d3bc04c2e3a5cf30
2015-01-12 11:09:27 +01:00

100 lines
3 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2009 by Bertrik Sikken
*
* 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"
/*
Backlight driver using the PWM mode of a hardware timer.
The PWM duty cycle depends exponentially on the configured brightness
level. This makes the brightness curve more linear to the human eye.
The button LEDs are all activated at the same time (even though there
are three individually controllable groups: menu/back, cursor, middle).
*/
void backlight_hw_brightness(int brightness)
{
/* pwm = round(16 * 16**(x/16)), where brightness level x = 1..16 */
static const unsigned int logtable[] =
{19, 23, 27, 32, 38, 45, 54, 64, 76, 91, 108, 128, 152, 181, 215, 256};
/* set PWM width */
TADATA0 = logtable[brightness];
}
void backlight_hw_on(void)
{
/* configure backlight pin P0.0 as timer PWM output */
PCON0 = ((PCON0 & ~(3 << 0)) | (2 << 0));
backlight_hw_brightness(backlight_brightness);
}
void backlight_hw_off(void)
{
/* configure backlight pin P0.0 as GPIO and switch off */
PCON0 = ((PCON0 & ~(3 << 0)) | (1 << 0));
PDAT0 &= ~(1 << 0);
}
void buttonlight_hw_on(void)
{
PDAT3 |= (3 << 2);
PDAT4 |= (1 << 2);
}
void buttonlight_hw_off(void)
{
PDAT3 &= ~(3 << 2);
PDAT4 &= ~(1 << 2);
}
bool backlight_hw_init(void)
{
/* Enable button LEDs: P3.2 (menu/back), P3.3 (cursor), P4.2 (middle) */
PCON3 = (PCON3 & ~0x0000FF00) | 0x00001100;
PCON4 = (PCON4 & ~0x00000F00) | 0x00000100;
buttonlight_hw_off();
/* enable timer clock */
PWRCON &= ~(1 << 4);
/* configure timer */
TACMD = (1 << 1); /* TA_CLR */
TACON = (0 << 13) | /* TA_INT1_EN */
(0 << 12) | /* TA_INT0_EN */
(1 << 11) | /* TA_START */
(3 << 8) | /* TA_CS = PCLK / 64 */
(1 << 4); /* TA_MODE_SEL = PWM mode */
TADATA1 = 256; /* set PWM period */
TAPRE = 20; /* prescaler */
TACMD = (1 << 0); /* TA_EN */
backlight_hw_on();
return true;
}