input: add zephyr,lvgl-button-input device binding

Add a pseudo device which can be used to hook into gpio-keys input_events
and relay the events to a lv_indev.

Signed-off-by: Fabian Blatz <[email protected]>

Author: faxe1008

dts/bindings/input/zephyr,lvgl-button-input.yaml

@@ -0,0 +1,36 @@
+# Copyright 2023 Fabian Blatz <[email protected]>
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  LVGL button indev pseudo-device
+
+  Listens for button input events and routes the
+  lv_indev_data_t to the underlying button lv_indev_t managed by LVGL.
+
+  Example configuration:
+
+  pointer {
+          compatible = "zephyr,lvgl-button-input";
+          input = <&buttons>;
+          input-codes = <INPUT_KEY_0 INPUT_KEY_1>;
+          coordinates = <120 220>, <150 250>;
+  };
+
+  When the device receives an input_event with code INPUT_KEY_0
+  a click event will be performed at (120,220).
+
+compatible: "zephyr,lvgl-button-input"
+
+include: zephyr,lvgl-common-input.yaml
+
+properties:
+  input-codes:
+    type: array
+    required: true
+    description: |
+      Array of input event key codes (INPUT_KEY_* or INPUT_BTN_*).
+
+  coordinates:
+    type: array
+    description: |
+      Array of points (x,y) the associated input-code is mapped to.

modules/lvgl/CMakeLists.txt

@@ -222,10 +222,11 @@ zephyr_library_sources(
 zephyr_library_sources_ifdef(CONFIG_LV_Z_USE_FILESYSTEM lvgl_fs.c)
 zephyr_library_sources_ifdef(CONFIG_LV_Z_MEM_POOL_SYS_HEAP lvgl_mem.c)
 zephyr_library_sources_ifdef(CONFIG_LV_Z_SHELL      lvgl_shell.c)
-zephyr_library_sources_ifdef(CONFIG_LV_Z_POINTER_KSCAN  input/lvgl_kscan_pointer.c)
 
 zephyr_library_sources(input/lvgl_common_input.c)
+zephyr_library_sources_ifdef(CONFIG_LV_Z_POINTER_KSCAN  input/lvgl_pointer_kscan.c)
 zephyr_library_sources_ifdef(CONFIG_LV_Z_POINTER_INPUT input/lvgl_pointer_input.c)
+zephyr_library_sources_ifdef(CONFIG_LV_Z_BUTTON_INPUT input/lvgl_button_input.c)
 
 zephyr_library_link_libraries(LVGL)
 target_link_libraries(LVGL INTERFACE zephyr_interface)

modules/lvgl/Kconfig.input

@@ -55,4 +55,17 @@ config LV_Z_POINTER_INPUT_MSGQ_COUNT
 	help
 	  Size of the pointer message queue buffering input events.
 
+config LV_Z_BUTTON_INPUT
+	bool "Input lvgl button"
+	default y
+	depends on INPUT
+	depends on DT_HAS_ZEPHYR_LVGL_BUTTON_INPUT_ENABLED
+
+config LV_Z_BUTTON_INPUT_MSGQ_COUNT
+	int "Input button queue message count"
+	default 4
+	depends on LV_Z_BUTTON_INPUT
+	help
+	  Size of the button message queue buffering input events.
+
 endmenu

modules/lvgl/input/lvgl_button_input.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2023 Fabian Blatz <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT zephyr_lvgl_button_input
+
+#include "lvgl_common_input.h"
+
+#include <zephyr/logging/log.h>
+
+LOG_MODULE_DECLARE(lvgl);
+
+struct lvgl_button_input_config {
+	struct lvgl_common_input_config common_config; /* Needs to be first member */
+	const uint16_t *input_codes;
+	uint8_t num_codes;
+	const lv_coord_t *coordinates;
+};
+
+static void lvgl_button_process_event(const struct device *dev, struct input_event *evt)
+{
+	struct lvgl_common_input_data *data = dev->data;
+	const struct lvgl_button_input_config *cfg = dev->config;
+	uint8_t i;
+
+	for (i = 0; i < cfg->num_codes; i++) {
+		if (evt->code == cfg->input_codes[i]) {
+			break;
+		}
+	}
+
+	if (i == cfg->num_codes) {
+		LOG_DBG("Ignored input event: %u", evt->code);
+		return;
+	}
+
+	data->pending_event.btn_id = i;
+	data->pending_event.state = evt->value ? LV_INDEV_STATE_PR : LV_INDEV_STATE_REL;
+
+	if (k_msgq_put(cfg->common_config.event_msgq, &data->pending_event, K_NO_WAIT) != 0) {
+		LOG_WRN("Could not put input data into queue");
+	}
+}
+
+static int lvgl_button_input_init(const struct device *dev)
+{
+	struct lvgl_common_input_data *data = dev->data;
+	const struct lvgl_button_input_config *cfg = dev->config;
+	int ret;
+
+	ret = lvgl_input_register_driver(LV_INDEV_TYPE_BUTTON, dev);
+	if (ret < 0) {
+		return ret;
+	}
+
+	lv_indev_set_button_points(data->indev, (const lv_point_t *)cfg->coordinates);
+
+	return ret;
+}
+
+#define ASSERT_PROPERTIES(inst)                                                                    \
+	BUILD_ASSERT(DT_INST_PROP_LEN(inst, input_codes) * 2 ==                                    \
+			     DT_INST_PROP_LEN(inst, coordinates),                                  \
+		     "Property coordinates must contain one coordinate per input-code.")
+
+#define LVGL_BUTTON_INPUT_DEFINE(inst)                                                             \
+	ASSERT_PROPERTIES(inst);                                                                   \
+	LVGL_INPUT_DEFINE(inst, button, CONFIG_LV_Z_BUTTON_INPUT_MSGQ_COUNT,                       \
+			  lvgl_button_process_event);                                              \
+	static const uint16_t lvgl_button_input_codes_##inst[] = DT_INST_PROP(inst, input_codes);  \
+	static const lv_coord_t lvgl_button_coordinates_##inst[] =                                 \
+		DT_INST_PROP(inst, coordinates);                                                   \
+	static const struct lvgl_button_input_config lvgl_button_input_config_##inst = {           \
+		.common_config.event_msgq = &LVGL_INPUT_EVENT_MSGQ(inst, button),                  \
+		.input_codes = lvgl_button_input_codes_##inst,                                     \
+		.num_codes = DT_INST_PROP_LEN(inst, input_codes),                                  \
+		.coordinates = lvgl_button_coordinates_##inst,                                     \
+	};                                                                                         \
+	static struct lvgl_common_input_data lvgl_common_input_data_##inst;                        \
+	DEVICE_DT_INST_DEFINE(inst, lvgl_button_input_init, NULL, &lvgl_common_input_data_##inst,  \
+			      &lvgl_button_input_config_##inst, APPLICATION,                       \
+			      CONFIG_LV_Z_INPUT_INIT_PRIORITY, NULL);
+
+DT_INST_FOREACH_STATUS_OKAY(LVGL_BUTTON_INPUT_DEFINE)