Add display interface abtraction layer

lv_port/lv_port_display_espressif.c

@@ -6,6 +6,29 @@
 #include "sdkconfig.h"
 #include "driver/gpio.h"
 
+#include "disp_spi.h"
+#include "lvgl_i2c/i2c_manager.h"
+
+#include <stdbool.h>
+#include <assert.h>
+
+/* NOTE: Needed by the I2C Manager */
+#define OLED_I2C_PORT                       (CONFIG_LV_I2C_DISPLAY_PORT)
+/* FIXME: Be able to get display driver I2C address from Kconfig */
+#if defined (CONFIG_LV_TFT_DISPLAY_CONTROLLER_SSD1306)
+#define OLED_I2C_ADDRESS    0x3C
+#endif
+
+#define LV_DISPLAY_DC_CMD_MODE    0
+#define LV_DISPLAY_DC_DATA_MODE   1
+
+/* Helper functions to get display communication interface kind, this can be
+ * implemented as users see fit, we're using the symbols created by Kconfig
+ * because is what we have available.
+ * Other ways to implement it is using the user_data poiter in lv_disp_drv_t */
+static inline bool display_interface_is_spi(lv_disp_drv_t * drv);
+static inline bool display_interface_is_i2c(lv_disp_drv_t * drv);
+
 void display_port_delay(lv_disp_drv_t *drv, uint32_t delay_ms)
 {
     (void) drv;
@@ -55,3 +78,76 @@ bool display_port_gpio_is_busy(lv_disp_drv_t *drv)
 
     return device_busy;
 }
+
+void display_interface_send_cmd(lv_disp_drv_t *drv, uint32_t cmd, cmd_width_t cmd_width, void *args, size_t args_len)
+{
+    (void) drv;
+
+    if (display_interface_is_spi(drv)) {
+        disp_wait_for_pending_transactions();
+        display_port_gpio_dc(drv, LV_DISPLAY_DC_CMD_MODE);
+
+        if (CMD_WIDTH_8BITS == cmd_width) {
+            disp_spi_send_data(&cmd, 1);
+        }
+        else if (CMD_WIDTH_16BITS == cmd_width) {
+            /* Send 16bits cmd */
+        }
+        else {
+            /* Invalid cmd size */
+            assert(0);
+        }
+
+        if (args != CMD_WITHOUT_ARGS) {
+            display_port_gpio_dc(drv, LV_DISPLAY_DC_DATA_MODE);
+            disp_spi_send_data(args, args_len);
+        }
+    }
+
+    if (display_interface_is_i2c(drv)) {
+        uint8_t *data = (uint8_t *) args;
+        lvgl_i2c_write(OLED_I2C_PORT, OLED_I2C_ADDRESS, cmd, data, args_len);
+    }
+}
+
+void display_interface_send_data(lv_disp_drv_t *drv, void *data, size_t len)
+{
+    (void) drv;
+
+    if (display_interface_is_spi(drv)) {
+        disp_wait_for_pending_transactions();
+        display_port_gpio_dc(drv, LV_DISPLAY_DC_DATA_MODE);
+        disp_spi_send_colors(data, len);
+        /* lv_disp_flush_ready is called in the SPI xfer done callback */
+    }
+
+    if (display_interface_is_i2c(drv)) {
+        lvgl_i2c_write(OLED_I2C_PORT, OLED_I2C_ADDRESS, OLED_CONTROL_BYTE_DATA_STREAM, data, len);
+    }
+}
+
+static inline bool display_interface_is_spi(lv_disp_drv_t * drv)
+{
+    (void) drv;
+
+    bool retval = false;
+
+#if defined (CONFIG_LV_TFT_DISPLAY_PROTOCOL_SPI)
+    retval = true;
+#endif
+
+    return retval;
+}
+
+static inline bool display_interface_is_i2c(lv_disp_drv_t * drv)
+{
+    (void) drv;
+
+    bool retval = false;
+
+#if defined (CONFIG_LV_TFT_DISPLAY_PROTOCOL_I2C)
+    retval = true;
+#endif
+
+    return retval;
+}

lvgl_tft/display_port.h

@@ -15,6 +15,16 @@ extern "C"
 #include <stdint.h>
 #include <stdbool.h>
 
+#define CMD_WITHOUT_ARGS    NULL
+
+enum {
+    CMD_WIDTH_8BITS,
+    CMD_WIDTH_16BITS,
+    CMD_WIDTH_INVALID,
+};
+
+typedef uint8_t cmd_width_t;
+
 /**
  * Busy wait delay port
  *
@@ -56,6 +66,28 @@ void display_port_gpio_rst(lv_disp_drv_t *drv, uint8_t state);
  */
 bool display_port_gpio_is_busy(lv_disp_drv_t *drv);
 
+/**
+ * Send cmd to display
+ *
+ * @param drv Pointer to driver
+ * @param cmd Command to send
+ * @param cmd_width Width of the command (in bits) to be sent, see @ref cmd_width_t
+ * @param args Pointer to arguments, use CMD_WITHOUT_ARGS to send command without arguments
+ * @param args_len Arguments length (in bytes) to be sent
+ */
+void display_interface_send_cmd(lv_disp_drv_t *drv, uint32_t cmd, cmd_width_t cmd_width, void *args, size_t args_len);
+
+/**
+ * Send (image) data to display
+ *
+ * User must call lv_disp_flush after the image is sent
+ *
+ * @param drv Pointer to driver
+ * @param data Pointer to data to be sent
+ * @param len Data length (in bytes) to be sent
+ */
+void display_interface_send_data(lv_disp_drv_t *drv, void *data, size_t len);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif