From 3c5a4061d94497689182c6509bf37c018ac7f510 Mon Sep 17 00:00:00 2001
From: C47D <carlos.santiago.diaz@gmail.com>
Date: Sat, 18 Sep 2021 20:14:35 -0500
Subject: [PATCH] feat(lv_port): Add abstraction for busy signal

This signal can be used when driving eink displays
---
 lv_port/lv_port_display_espressif.c | 16 ++++++++++++++++
 lvgl_tft/display_port.h             | 18 ++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/lv_port/lv_port_display_espressif.c b/lv_port/lv_port_display_espressif.c
index 9f6f4b1..79aaa40 100644
--- a/lv_port/lv_port_display_espressif.c
+++ b/lv_port/lv_port_display_espressif.c
@@ -39,3 +39,19 @@ void display_port_gpio_rst(lv_disp_drv_t *drv, uint8_t state)
     gpio_set_level(CONFIG_LV_DISP_PIN_RST, state);
 #endif
 }
+
+display_port_busy_t display_port_gpio_is_busy(lv_disp_drv_t *drv)
+{
+    (void) drv;
+
+    display_port_busy_t device_busy = DISPLAY_PORT_DEVICE_NOT_BUSY;
+
+#ifdef CONFIG_LV_DISP_PIN_BUSY
+    /* FIXME Assuming the busy signal in logic 1 means the device is busy */
+    if (gpio_get_level(CONFIG_LV_DISP_PIN_BUSY) == 1) {
+        device_busy = DISPLAY_PORT_DEVICE_IS_BUSY;
+    }
+#endif
+
+    return device_busy;
+}
diff --git a/lvgl_tft/display_port.h b/lvgl_tft/display_port.h
index 2136ec6..bd58fe7 100644
--- a/lvgl_tft/display_port.h
+++ b/lvgl_tft/display_port.h
@@ -12,6 +12,14 @@ extern "C"
 #include "lvgl/lvgl.h"
 #endif
 
+/** Display is busy port
+ * Useful for eink displays that need to poll their BUSY signal */
+typedef enum {
+    DISPLAY_PORT_DEVICE_NOT_BUSY,
+    DISPLAY_PORT_DEVICE_IS_BUSY,
+    /* NOTE Operation should not be interrupted when the device is busy */
+} display_port_busy_t;
+
 /**
  * Busy wait delay port
  *
@@ -44,6 +52,16 @@ void display_port_gpio_dc(lv_disp_drv_t *drv, uint8_t state);
  */
 void display_port_gpio_rst(lv_disp_drv_t *drv, uint8_t state);
 
+/**
+ * Display is busy port
+ *
+ * @param drv Pointer to driver See @ref lv_disp_drv_t
+ *
+ * @retval Returns DISPLAY_PORT_DEVICE_NOT_BUSY when display is not busy,
+ * DISPLAY_PORT_DEVICE_IS_BUSY otherwise.
+ */
+display_port_busy_t display_port_gpio_is_busy(lv_disp_drv_t *drv);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif