60 lines
2.4 KiB
C
60 lines
2.4 KiB
C
/***************************************************************************
|
|
* Copyright (C) 2020 by Federico Amedeo Izzo IU2NUO, *
|
|
* Niccolò Izzo IU2KIN *
|
|
* Silvano Seva IU2KWO *
|
|
* *
|
|
* 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 3 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/> *
|
|
***************************************************************************/
|
|
|
|
#include <stm32f4xx.h>
|
|
#include "platform.h"
|
|
#include "gpio.h"
|
|
|
|
void platform_init()
|
|
{
|
|
/*
|
|
* Configure TIM8 for backlight PWM: Fpwm = 100kHz, 8 bit of resolution
|
|
* APB2 freq. is 84MHz, then: PSC = 327 to have Ftick = 256.097kHz
|
|
* With ARR = 256, Fpwm is 100kHz;
|
|
*/
|
|
RCC->APB2ENR |= RCC_APB2ENR_TIM8EN;
|
|
TIM8->ARR = 255;
|
|
TIM8->PSC = 327;
|
|
TIM8->CNT = 0;
|
|
TIM8->CR1 |= TIM_CR1_ARPE; /* LCD backlight is on PC6, TIM8-CH1 */
|
|
TIM8->CCMR1 |= TIM_CCMR1_OC1M_2
|
|
| TIM_CCMR1_OC1M_1
|
|
| TIM_CCMR1_OC1PE;
|
|
TIM8->CCER |= TIM_CCER_CC1E;
|
|
TIM8->BDTR |= TIM_BDTR_MOE;
|
|
TIM8->CCR1 = 0;
|
|
TIM8->EGR = TIM_EGR_UG; /* Update registers */
|
|
TIM8->CR1 |= TIM_CR1_CEN; /* Start timer */
|
|
|
|
/* Configure backlight GPIO, TIM8 is on AF3 */
|
|
gpio_setMode(GPIOC, 6, ALTERNATE);
|
|
gpio_setAlternateFunction(GPIOC, 6, 3);
|
|
}
|
|
|
|
void platform_terminate()
|
|
{
|
|
/* Shut off backlight */
|
|
RCC->APB2ENR &= ~RCC_APB2ENR_TIM8EN;
|
|
}
|
|
|
|
void platform_setBacklightLevel(uint8_t level)
|
|
{
|
|
TIM8->CCR1 = level;
|
|
}
|