110 lines
3.5 KiB
C
110 lines
3.5 KiB
C
/**
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* @file esp_lcd_backlight.c
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*
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*/
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/*********************
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* INCLUDES
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*********************/
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#include "esp_lcd_backlight.h"
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#include "driver/ledc.h"
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#include "rom/gpio.h"
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#include "esp_log.h"
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#include "soc/ledc_periph.h" // to invert LEDC output on IDF version < v4.3
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#define SIG_GPIO_OUT_IDX 128
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typedef struct {
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bool pwm_control; // true: LEDC is used, false: GPIO is used
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int index; // Either GPIO or LEDC channel
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} disp_backlight_t;
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static const char *TAG = "disp_backlight";
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disp_backlight_h disp_backlight_new(const disp_backlight_config_t *config)
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{
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// Check input parameters
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if (config == NULL)
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return NULL;
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if (!GPIO_IS_VALID_OUTPUT_GPIO(config->gpio_num)) {
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ESP_LOGW(TAG, "Invalid GPIO number");
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return NULL;
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}
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disp_backlight_t *bckl_dev = calloc(1, sizeof(disp_backlight_t));
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if (bckl_dev == NULL){
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ESP_LOGW(TAG, "Not enough memory");
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return NULL;
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}
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if (config->pwm_control){
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// Configure LED (Backlight) pin as PWM for Brightness control.
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bckl_dev->pwm_control = true;
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bckl_dev->index = config->channel_idx;
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const ledc_channel_config_t LCD_backlight_channel = {
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.gpio_num = config->gpio_num,
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.speed_mode = LEDC_LOW_SPEED_MODE,
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.channel = config->channel_idx,
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.intr_type = LEDC_INTR_DISABLE,
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.timer_sel = config->timer_idx,
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.duty = 0,
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.hpoint = 0
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};
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const ledc_timer_config_t LCD_backlight_timer = {
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.speed_mode = LEDC_LOW_SPEED_MODE,
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.duty_resolution = LEDC_TIMER_10_BIT,
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.timer_num = config->timer_idx,
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.freq_hz = 5000,
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.clk_cfg = LEDC_AUTO_CLK};
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ESP_ERROR_CHECK(ledc_timer_config(&LCD_backlight_timer));
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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);
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}
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else
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{
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// Configure GPIO for output
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bckl_dev->index = config->gpio_num;
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gpio_pad_select_gpio(config->gpio_num);
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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);
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}
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return (disp_backlight_h)bckl_dev;
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}
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void disp_backlight_set(disp_backlight_h bckl, int brightness_percent)
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{
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// Check input paramters
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if (bckl == NULL)
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return;
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if (brightness_percent > 100)
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brightness_percent = 100;
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if (brightness_percent < 0)
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brightness_percent = 0;
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disp_backlight_t *bckl_dev = (disp_backlight_t *) bckl;
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ESP_LOGI(TAG, "Setting LCD backlight: %d%%", brightness_percent);
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if (bckl_dev->pwm_control) {
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uint32_t duty_cycle = (1023 * brightness_percent) / 100; // LEDC resolution set to 10bits, thus: 100% = 1023
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ESP_ERROR_CHECK(ledc_set_duty(LEDC_LOW_SPEED_MODE, bckl_dev->index, duty_cycle));
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ESP_ERROR_CHECK(ledc_update_duty(LEDC_LOW_SPEED_MODE, bckl_dev->index));
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} else {
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ESP_ERROR_CHECK(gpio_set_level(bckl_dev->index, brightness_percent));
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}
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}
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void disp_backlight_delete(disp_backlight_h bckl)
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{
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if (bckl == NULL)
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return;
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disp_backlight_t *bckl_dev = (disp_backlight_t *) bckl;
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if (bckl_dev->pwm_control) {
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ledc_stop(LEDC_LOW_SPEED_MODE, bckl_dev->index, 0);
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} else {
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gpio_reset_pin(bckl_dev->index);
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}
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free (bckl);
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}
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