keychron_qmk_firmware/keyboards/bface/backlight_ps2avrGB.c

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/* Copyright 2017 Sebastian Kaim
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifdef BACKLIGHT_ENABLE
#include "backlight_ps2avrGB.h"
#define sbi(reg,bit) reg |= (_BV(bit))
#define cbi(reg,bit) reg &= (~_BV(bit))
#define PWM10 WGM10
#define PWM11 WGM11
#define COM1x1 COM1B1
#define OCR1x OCR1B
void backlight_init_ports(void)
{
#if BACKLIGHT_ON_STATE == 0
backlight_off();
#else
backlight_on();
#endif
// setup pwm
// this bitmagic is sourced from the original firmware
/*TCCR1B = ((TCCR1B & ~0x07) | 0x03);
TCNT1H = 0;
TCNT1L = 0;
sbi(TIMSK, TOIE1);
OCR1BH = 0;
OCR1BL = 0;
cbi(TCCR1A,PWM11);
sbi(TCCR1A,PWM10);
sbi(TCCR1A,COM1B1);
cbi(TCCR1A,COM1B0);*/
ICR1 = 0xFFFF;
TCCR1A = _BV(COM1x1) | _BV(WGM11); // = 0b00001010;
TCCR1B = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001;
backlight_init();
}
void backlight_set(uint8_t level)
{
if( level == 0 ) {
backlight_off();
}
else {
backlight_on();
/*uint8_t pwm = get_pwm_for_brightness(level);
set_backlight_pwm(pwm);
TCCR1A |= _BV(COM1x1);
OCR1x = (level >= 2) ? 0xFFFF : 0x00FF;*/
}
}
#define PWM_MAX 0xFF
uint8_t get_pwm_for_brightness(uint8_t level)
{
// we need to cast up here to allow multiplication with 0xFF. We could also use floats, but this is probably a lot faster.
uint16_t brightness = (uint16_t)level * (uint16_t)PWM_MAX / (uint16_t)BACKLIGHT_LEVELS;
return (uint8_t)brightness;
}
void backlight_on(void)
{
//_SFR_IO8(0x12) |= _BV(0x4);
LED_PIN |= BACKLIGHT_PORT_NUM;
}
void backlight_off(void)
{
//_SFR_IO8(0x12) &= ~_BV(0x4);
LED_PIN &= ~BACKLIGHT_PORT_NUM;
}
void set_backlight_pwm(uint8_t level) {
// this does not work (yet)
//OCR1B = level;
}
#endif // BACKLIGHT_ENABLE