rockbox/firmware/target/arm/imx31/gigabeat-s/backlight-imx31.c
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

114 lines
3.9 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Linus Nielsen Feltzing
*
* 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 "system.h"
#include "backlight.h"
#include "mc13783.h"
#include "backlight-target.h"
#ifdef HAVE_BACKLIGHT_BRIGHTNESS
/* Table that uses combinations of current level and pwm fraction to get
* as many uniquely-visible brightness levels as possible. The lowest current
* level for any average current is used even though many combinations give
* duplicate values. Current (I) values are in mA. */
static const struct
{
unsigned char md;
unsigned char pwm;
} led_md_pwm_table[] =
{
/* I-level PWM(x/15) I-Avg */
{ 0, 0 }, /* 0 0 0.0 */
{ 1, 1 }, /* 3 1 0.2 */
{ 1, 2 }, /* 3 2 0.4 */
{ 1, 3 }, /* 3 3 0.6 */
{ 1, 4 }, /* 3 4 0.8 */
{ 1, 5 }, /* 3 5 1.0 */
{ 1, 6 }, /* 3 6 1.2 */
{ 1, 7 }, /* 3 7 1.4 */
{ 1, 8 }, /* 3 8 1.6 */
{ 1, 9 }, /* 3 9 1.8 */
{ 1, 10 }, /* 3 10 2.0 */
{ 1, 11 }, /* 3 11 2.2 */
{ 1, 12 }, /* 3 12 2.4 */ /* default */
{ 1, 13 }, /* 3 13 2.6 */
{ 1, 14 }, /* 3 14 2.8 */
{ 1, 15 }, /* 3 15 3.0 */
{ 2, 9 }, /* 6 9 3.6 */
{ 2, 10 }, /* 6 10 4.0 */
{ 2, 11 }, /* 6 11 4.4 */
{ 2, 12 }, /* 6 12 4.8 */
{ 2, 13 }, /* 6 13 5.2 */
{ 2, 14 }, /* 6 14 5.6 */
{ 2, 15 }, /* 6 15 6.0 */
{ 3, 11 }, /* 9 11 6.6 */
{ 3, 12 }, /* 9 12 7.2 */
/* Anything higher is just too much */
};
#endif /* HAVE_BACKLIGHT_BRIGHTNESS */
bool _backlight_init(void)
{
mc13783_write(MC13783_LED_CONTROL0,
MC13783_LEDEN |
MC13783_LEDMDRAMPUP |
MC13783_LEDMDRAMPDOWN |
MC13783_BOOSTEN |
MC13783_ABMODE_MONCH_LEDMD1234 |
MC13783_ABREF_400MV);
return true;
}
void _backlight_on(void)
{
/* LEDEN=1 */
mc13783_set(MC13783_LED_CONTROL0, MC13783_LEDEN);
}
void _backlight_off(void)
{
/* LEDEN=0 */
mc13783_clear(MC13783_LED_CONTROL0, MC13783_LEDEN);
}
#ifdef HAVE_BACKLIGHT_BRIGHTNESS
/* Assumes that the backlight has been initialized */
void _backlight_set_brightness(int brightness)
{
uint32_t data, md, pwm;
if ((unsigned)brightness >= ARRAYLEN(led_md_pwm_table))
brightness = DEFAULT_BRIGHTNESS_SETTING;
data = mc13783_read(MC13783_LED_CONTROL2);
if (data == (uint32_t)-1)
return;
md = led_md_pwm_table[brightness].md;
pwm = led_md_pwm_table[brightness].pwm;
data &= ~(MC13783_LEDMD | MC13783_LEDMDDC);
data |= MC13783_LEDMDw(md) | MC13783_LEDMDDCw(pwm);
mc13783_write(MC13783_LED_CONTROL2, data);
}
#endif /* HAVE_BACKLIGHT_BRIGHTNESS */