feat(i80_lcd): add help function to allocate draw buffer with proper alignment

components/esp_lcd/i80/esp_lcd_panel_io_i2s.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -321,6 +321,14 @@ err:
     return ret;
 }
 
+void *esp_lcd_i80_alloc_draw_buffer(esp_lcd_panel_io_handle_t io, size_t size, uint32_t caps)
+{
+    ESP_RETURN_ON_FALSE(io, NULL, TAG, "invalid argument");
+    ESP_RETURN_ON_FALSE((caps & MALLOC_CAP_SPIRAM) == 0, NULL, TAG, "external memory is not supported");
+    // DMA can only carry internal memory
+    return heap_caps_aligned_calloc(4, 1, size, MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT | MALLOC_CAP_DMA);
+}
+
 static esp_err_t panel_io_i80_del(esp_lcd_panel_io_t *io)
 {
     lcd_panel_io_i80_t *i80_device = __containerof(io, lcd_panel_io_i80_t, base);

components/esp_lcd/i80/esp_lcd_panel_io_i80.c

@@ -583,6 +583,21 @@ err:
     return ret;
 }
 
+void *esp_lcd_i80_alloc_draw_buffer(esp_lcd_panel_io_handle_t io, size_t size, uint32_t caps)
+{
+    ESP_RETURN_ON_FALSE(io, NULL, TAG, "invalid argument");
+    lcd_panel_io_i80_t *i80_device = __containerof(io, lcd_panel_io_i80_t, base);
+    esp_lcd_i80_bus_t *bus = i80_device->bus;
+    void *buf = NULL;
+    // alloc from external memory
+    if (caps & MALLOC_CAP_SPIRAM) {
+        buf = heap_caps_aligned_calloc(bus->ext_mem_align, 1, size, MALLOC_CAP_8BIT | MALLOC_CAP_SPIRAM | MALLOC_CAP_DMA);
+    } else {
+        buf = heap_caps_aligned_calloc(bus->int_mem_align, 1, size, MALLOC_CAP_8BIT | MALLOC_CAP_INTERNAL | MALLOC_CAP_DMA);
+    }
+    return buf;
+}
+
 static esp_err_t lcd_i80_bus_configure_gpio(esp_lcd_i80_bus_handle_t bus, const esp_lcd_i80_bus_config_t *bus_config)
 {
     int bus_id = bus->bus_id;

components/esp_lcd/include/esp_lcd_io_i80.h

@@ -100,6 +100,18 @@ typedef struct {
  */
 esp_err_t esp_lcd_new_panel_io_i80(esp_lcd_i80_bus_handle_t bus, const esp_lcd_panel_io_i80_config_t *io_config, esp_lcd_panel_io_handle_t *ret_io);
 
+/**
+ * @brief Allocate a draw buffer that can be used by I80 interfaced LCD panel
+ *
+ * @note This function differs from the normal 'heap_caps_*' functions in that it can also automatically handle the alignment required by DMA burst, cache line size, etc.
+ *
+ * @param[in] io Panel IO handle, created by `esp_lcd_new_panel_io_i80()`
+ * @param[in] size Size of memory to be allocated
+ * @param[in] caps Bitwise OR of MALLOC_CAP_* flags indicating the type of memory desired for the allocation
+ * @return Pointer to a new buffer of size 'size' with capabilities 'caps', or NULL if allocation failed
+ */
+void *esp_lcd_i80_alloc_draw_buffer(esp_lcd_panel_io_handle_t io, size_t size, uint32_t caps);
+
 #endif // SOC_LCD_I80_SUPPORTED
 
 #ifdef __cplusplus

examples/peripherals/lcd/i80_controller/main/i80_controller_example_main.c

@@ -9,6 +9,7 @@
 #include "freertos/task.h"
 #include "freertos/semphr.h"
 #include "esp_timer.h"
+#include "esp_heap_caps.h"
 #include "esp_lcd_panel_io.h"
 #include "esp_lcd_panel_vendor.h"
 #include "esp_lcd_panel_ops.h"
@@ -18,7 +19,6 @@
 #include "driver/i2c.h"
 #include "esp_err.h"
 #include "esp_log.h"
-#include "esp_dma_utils.h"
 #include "lvgl.h"
 #if CONFIG_EXAMPLE_LCD_TOUCH_CONTROLLER_GT911
 #include "esp_lcd_touch_gt911.h"
@@ -443,18 +443,12 @@ void app_main(void)
     lv_init();
     // alloc draw buffers used by LVGL
     // it's recommended to choose the size of the draw buffer(s) to be at least 1/10 screen sized
-    lv_color_t *buf1 = NULL;
+    uint32_t draw_buf_alloc_caps = 0;
-    lv_color_t *buf2 = NULL;
-    esp_dma_mem_info_t dma_mem_info = {
-        .dma_alignment_bytes = 4,
 #if CONFIG_EXAMPLE_LCD_I80_COLOR_IN_PSRAM
-        .extra_heap_caps = MALLOC_CAP_SPIRAM,
+    draw_buf_alloc_caps |= MALLOC_CAP_SPIRAM;
-#else
+#endif
-        .extra_heap_caps = MALLOC_CAP_INTERNAL,
+    lv_color_t *buf1 = esp_lcd_i80_alloc_draw_buffer(io_handle, EXAMPLE_LCD_H_RES * 100 * sizeof(lv_color_t), draw_buf_alloc_caps);
-#endif // CONFIG_EXAMPLE_LCD_I80_COLOR_IN_PSRAM
+    lv_color_t *buf2 = esp_lcd_i80_alloc_draw_buffer(io_handle, EXAMPLE_LCD_H_RES * 100 * sizeof(lv_color_t), draw_buf_alloc_caps);
-    };
-    ESP_ERROR_CHECK(esp_dma_capable_malloc(EXAMPLE_LCD_H_RES * 100 * sizeof(lv_color_t), &dma_mem_info, (void *)&buf1, NULL));
-    ESP_ERROR_CHECK(esp_dma_capable_malloc(EXAMPLE_LCD_H_RES * 100 * sizeof(lv_color_t), &dma_mem_info, (void *)&buf2, NULL));
     assert(buf1);
     assert(buf2);
     ESP_LOGI(TAG, "buf1@%p, buf2@%p", buf1, buf2);