rockbox/firmware/target/arm/rk27xx/backlight-rk27xx.c
Andrew Ryabinin 3a97e12fc5 Introduce HiFi E.T. MA8/MA8C ports.
HiFi E.T. MA8 is almost the same as MA9 except
another DAC(pcm1792 in ma8, df1704 in ma9).

MA8 has ILI9342 lcd, MA8C has ILI9342C lcd.

Change-Id: If2ac04f5a3382590b2a392c46286559f54b2ed6a
2013-11-05 09:59:45 +04:00

135 lines
4.1 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
};
#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];
}