Merge pull request #99 from lvgl/fix/backlight-off

Don't call backlight function when backlight is disabled

Author: tore-espressif

lvgl_tft/Kconfig

@@ -934,16 +934,9 @@ menu "LVGL TFT Display controller"
     endchoice
 
     choice
+        default LV_DISP_BACKLIGHT_SWITCH
         prompt "Backlight Control" if \
             (! ( LV_TFT_DISPLAY_CONTROLLER_SH1107 || LV_TFT_DISPLAY_CONTROLLER_SSD1306 ) )
-        default LV_DISP_BACKLIGHT_SWITCH if LV_PREDEFINED_DISPLAY_M5STACK
-        default LV_DISP_BACKLIGHT_OFF if LV_PREDEFINED_DISPLAY_M5CORE2
-        default LV_DISP_BACKLIGHT_SWITCH if LV_PREDEFINED_DISPLAY_WROVER4
-        default LV_DISP_BACKLIGHT_SWITCH if LV_PREDEFINED_DISPLAY_ERTFT0356
-        default LV_DISP_BACKLIGHT_SWITCH if LV_PREDEFINED_DISPLAY_TTGO
-        default LV_DISP_BACKLIGHT_SWITCH if LV_PREDEFINED_DISPLAY_TTGO_CAMERA_PLUS
-        default LV_DISP_BACKLIGHT_SWITCH if LV_PREDEFINED_DISPLAY_WT32_SC01
-        default LV_DISP_BACKLIGHT_OFF
 
         config LV_DISP_BACKLIGHT_OFF
             bool
@@ -995,7 +988,7 @@ menu "LVGL TFT Display controller"
         default 4 if LV_PREDEFINED_DISPLAY_TTGO
         default 2 if LV_PREDEFINED_DISPLAY_TTGO_CAMERA_PLUS
         default 23 if LV_PREDEFINED_DISPLAY_WT32_SC01
-        default 27
+        default -1
 
         help
             Configure the display BCLK (LED) pin here.

lvgl_tft/disp_driver.c

@@ -47,7 +47,7 @@ void *disp_driver_init(void)
 
     // We still use menuconfig for these settings
     // It will be set up during runtime in the future
-#ifndef CONFIG_LV_DISP_BACKLIGHT_OFF
+#if (defined(CONFIG_LV_DISP_BACKLIGHT_SWITCH) || defined(CONFIG_LV_DISP_BACKLIGHT_PWM))
     const disp_backlight_config_t bckl_config = {
         .gpio_num = CONFIG_LV_DISP_PIN_BCKL,
 #if defined CONFIG_LV_DISP_BACKLIGHT_PWM
@@ -63,15 +63,12 @@ void *disp_driver_init(void)
         .timer_idx = 0,
         .channel_idx = 0 // @todo this prevents us from having two PWM controlled displays
     };
-    const disp_backlight_config_t *bckl_config_p = &bckl_config;
-#else
-    const disp_backlight_config_t *bckl_config_p = NULL;
-#endif
-
-    disp_backlight_h bckl_handle = disp_backlight_new(bckl_config_p);
+    disp_backlight_h bckl_handle = disp_backlight_new(&bckl_config);
     disp_backlight_set(bckl_handle, 100);
-
     return bckl_handle;
+#else
+    return NULL;
+#endif
 }
 
 void disp_driver_flush(lv_disp_drv_t * drv, const lv_area_t * area, lv_color_t * color_map)

lvgl_tft/esp_lcd_backlight.c

@@ -10,7 +10,6 @@
 #include "driver/ledc.h"
 #include "driver/gpio.h"
 #include "esp_log.h"
-#include "esp_rom_gpio.h"    // for output signal inversion
 #include "soc/ledc_periph.h" // to invert LEDC output on IDF version < v4.3
 
 typedef struct {
@@ -22,11 +21,16 @@ 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, "Could not create new LCD backlight instance");
+        ESP_LOGW(TAG, "Not enough memory");
         return NULL;
     }
 
@@ -52,15 +56,15 @@ disp_backlight_h disp_backlight_new(const disp_backlight_config_t *config)
 
         ESP_ERROR_CHECK(ledc_timer_config(&LCD_backlight_timer));
         ESP_ERROR_CHECK(ledc_channel_config(&LCD_backlight_channel));
-        esp_rom_gpio_connect_out_signal(config->gpio_num, ledc_periph_signal[LEDC_LOW_SPEED_MODE].sig_out0_idx + config->channel_idx, config->output_invert, 0);
+        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));
-        esp_rom_gpio_connect_out_signal(config->gpio_num, SIG_GPIO_OUT_IDX, config->output_invert, false);
+        gpio_matrix_out(config->gpio_num, SIG_GPIO_OUT_IDX, config->output_invert, false);
     }
 
     return (disp_backlight_h)bckl_dev;