lvgl_esp32_drivers/lvgl_tft/esp_lcd_backlight.c

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/**
* @file esp_lcd_backlight.c
*
*/
/*********************
* INCLUDES
*********************/
#include "esp_lcd_backlight.h"
#include "driver/ledc.h"
#include "driver/gpio.h"
#include "esp_log.h"
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#include "soc/ledc_periph.h" // to invert LEDC output on IDF version < v4.3
typedef struct {
bool pwm_control; // true: LEDC is used, false: GPIO is used
int index; // Either GPIO or LEDC channel
} disp_backlight_t;
static const char *TAG = "disp_backlight";
disp_backlight_h disp_backlight_new(const disp_backlight_config_t *config)
{
// Check input parameters
if (config == NULL)
return NULL;
if (!GPIO_IS_VALID_OUTPUT_GPIO(config->gpio_num)) {
ESP_LOGW(TAG, "Invalid GPIO number");
return NULL;
}
disp_backlight_t *bckl_dev = calloc(1, sizeof(disp_backlight_t));
if (bckl_dev == NULL){
ESP_LOGW(TAG, "Not enough memory");
return NULL;
}
if (config->pwm_control){
// Configure LED (Backlight) pin as PWM for Brightness control.
bckl_dev->pwm_control = true;
bckl_dev->index = config->channel_idx;
const ledc_channel_config_t LCD_backlight_channel = {
.gpio_num = config->gpio_num,
.speed_mode = LEDC_LOW_SPEED_MODE,
.channel = config->channel_idx,
.intr_type = LEDC_INTR_DISABLE,
.timer_sel = config->timer_idx,
.duty = 0,
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.hpoint = 0
};
const ledc_timer_config_t LCD_backlight_timer = {
.speed_mode = LEDC_LOW_SPEED_MODE,
.bit_num = LEDC_TIMER_10_BIT,
.timer_num = config->timer_idx,
.freq_hz = 5000,
.clk_cfg = LEDC_AUTO_CLK};
ESP_ERROR_CHECK(ledc_timer_config(&LCD_backlight_timer));
ESP_ERROR_CHECK(ledc_channel_config(&LCD_backlight_channel));
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gpio_matrix_out(config->gpio_num, ledc_periph_signal[LEDC_LOW_SPEED_MODE].sig_out0_idx + config->channel_idx, config->output_invert, 0);
}
else
{
// Configure GPIO for output
bckl_dev->index = config->gpio_num;
gpio_pad_select_gpio(config->gpio_num);
ESP_ERROR_CHECK(gpio_set_direction(config->gpio_num, GPIO_MODE_OUTPUT));
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gpio_matrix_out(config->gpio_num, SIG_GPIO_OUT_IDX, config->output_invert, false);
}
return (disp_backlight_h)bckl_dev;
}
void disp_backlight_set(disp_backlight_h bckl, int brightness_percent)
{
// Check input paramters
if (bckl == NULL)
return;
if (brightness_percent > 100)
brightness_percent = 100;
if (brightness_percent < 0)
brightness_percent = 0;
disp_backlight_t *bckl_dev = (disp_backlight_t *) bckl;
ESP_LOGI(TAG, "Setting LCD backlight: %d%%", brightness_percent);
if (bckl_dev->pwm_control) {
uint32_t duty_cycle = (1023 * brightness_percent) / 100; // LEDC resolution set to 10bits, thus: 100% = 1023
ESP_ERROR_CHECK(ledc_set_duty(LEDC_LOW_SPEED_MODE, bckl_dev->index, duty_cycle));
ESP_ERROR_CHECK(ledc_update_duty(LEDC_LOW_SPEED_MODE, bckl_dev->index));
} else {
ESP_ERROR_CHECK(gpio_set_level(bckl_dev->index, brightness_percent));
}
}
void disp_backlight_delete(disp_backlight_h bckl)
{
if (bckl == NULL)
return;
disp_backlight_t *bckl_dev = (disp_backlight_t *) bckl;
if (bckl_dev->pwm_control) {
ledc_stop(LEDC_LOW_SPEED_MODE, bckl_dev->index, 0);
} else {
gpio_reset_pin(bckl_dev->index);
}
free (bckl);
}