142 lines
4.3 KiB
C
142 lines
4.3 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"
|
|
#include "lcd.h"
|
|
|
|
static int brightness = DEFAULT_BRIGHTNESS_SETTING;
|
|
|
|
/* Based on http://www.poynton.com/PDFs/SMPTE93_Gamma.pdf
|
|
* CIE standarized function that relates physical luminance
|
|
* to perceived lightness
|
|
*
|
|
* L* = 116*(Y/Yn)^(1/3) - 16 (Y/Yn > 0 008856)
|
|
* where Yn is luminance of reference white
|
|
*
|
|
* Actual function is lightly tweaked to account for the fact
|
|
* that fill factor of the PWM below some value gives black.
|
|
* So the function used to calculate the values in the matrix was:
|
|
* f(x) = (PWM_FREQ_MAX - PWM_FREQ_MIN) * ((100*x/31 + 16)/116)^3 + PWM_FREQ_MIN
|
|
*/
|
|
#ifdef RK27_GENERIC
|
|
static const unsigned short lin_brightness[] = {
|
|
8110, 8191, 8304, 8455, 8649, 8892, 9189, 9545,
|
|
9966, 10457, 11024, 11671, 12406, 13232, 14156, 15182,
|
|
16316, 17565, 18932, 20423, 22045, 23801, 25699, 27742,
|
|
29937, 32289, 34803, 37485, 40340, 43374, 46592, 50000
|
|
};
|
|
#elif defined(HM801)
|
|
static const unsigned short lin_brightness[] = {
|
|
541, 542, 543, 544, 547, 549, 553, 556,
|
|
561, 566, 573, 580, 588, 597, 607, 618,
|
|
631, 644, 659, 676, 693, 713, 733, 756,
|
|
780, 806, 833, 862, 894, 927, 962, 1000
|
|
};
|
|
#elif defined(HM60X)
|
|
static const unsigned short lin_brightness[] = {
|
|
456, 457, 458, 460, 463, 466, 470, 475,
|
|
480, 486, 494, 502, 512, 522, 534, 548,
|
|
562, 579, 596, 616, 637, 660, 684, 711,
|
|
739, 770, 802, 837, 874, 914, 955, 1000
|
|
};
|
|
#elif defined(MA9) || defined(MA9C) || defined(MA8) || defined(MA8C)
|
|
static const unsigned short lin_brightness[] = {
|
|
2, 4, 7, 10, 15, 21, 28, 36,
|
|
46, 58, 72, 87, 104, 124, 146, 171,
|
|
198, 227, 260, 295, 334, 376, 421, 470,
|
|
522, 578, 638, 702, 770, 842, 918, 1000
|
|
};
|
|
#elif defined(IHIFI760) || defined(IHIFI960)
|
|
static const unsigned short lin_brightness[] = {
|
|
700, 701, 702, 703, 704, 706, 708, 711,
|
|
714, 717, 721, 726, 731, 737, 743, 751,
|
|
759, 768, 778, 788, 800, 812, 826, 841,
|
|
856, 873, 891, 910, 931, 952, 975, 1000
|
|
};
|
|
#endif
|
|
|
|
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 */
|
|
/* (apb_freq/pwm_freq)/pwm_div = (50 000 000/pwm_freq)/2 */
|
|
PWMT0_LRC = lin_brightness[MAX_BRIGHTNESS_SETTING];
|
|
PWMT0_HRC = lin_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)
|
|
{
|
|
#ifdef HAVE_LCD_ENABLE
|
|
lcd_enable(true);
|
|
#endif
|
|
/* enable PWM clock */
|
|
SCU_CLKCFG &= ~CLKCFG_PWM;
|
|
|
|
/* 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 |= CLKCFG_PWM;
|
|
#ifdef HAVE_LCD_ENABLE
|
|
lcd_enable(false);
|
|
#endif
|
|
}
|
|
|
|
void _backlight_set_brightness(int val)
|
|
{
|
|
brightness = val & 0x1f;
|
|
PWMT0_HRC = lin_brightness[brightness];
|
|
}
|