modules: lvgl: input: add zephyr,lvgl-keypad-input device binding

Add a pseudo device which can be used to hook into input events and
emit lvgl keypad events.

Signed-off-by: Fabian Blatz <fabianblatz@gmail.com>

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

@@ -0,0 +1,41 @@
+# Copyright 2023 Fabian Blatz <fabianblatz@gmail.com>
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  LVGL keypad indev pseudo-device
+
+  Listens for input events and routes the
+  lv_indev_data_t to the underlying keypad lv_indev_t managed by LVGL.
+
+  The property input-codes can be used to setup a mapping of input codes
+  to the lvgl keys. There are lvgl keys that have a special function:
+  https://docs.lvgl.io/master/overview/indev.html#keys.
+
+  The pseudo device can be associated to a specific device to listen only
+  for events from that device. Example configuration:
+
+  #include <zephyr/dt-bindings/lvgl/lvgl.h>
+
+  keypad {
+          compatible = "zephyr,lvgl-keypad-input";
+          input = <&buttons>;
+          input-codes = <INPUT_KEY_1, INPUT_KEY_2>;
+          lvgl-codes = <LV_KEY_NEXT, LV_KEY_PREV>;
+  };
+
+compatible: "zephyr,lvgl-keypad-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_*).
+
+  lvgl-codes:
+    type: array
+    required: true
+    description: |
+      Array of mapped lvgl keys.

include/zephyr/dt-bindings/lvgl/lvgl.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023 Fabian Blatz <fabianblatz@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#ifndef ZEPHYR_INCLUDE_DT_BINDINGS_LVGL_LVGL_H_
+#define ZEPHYR_INCLUDE_DT_BINDINGS_LVGL_LVGL_H_
+
+/* Predefined keys to control the focused object.
+ * Values taken from enum _lv_key_t in lv_group.h
+ */
+#define LV_KEY_UP        17
+#define LV_KEY_DOWN      18
+#define LV_KEY_RIGHT     19
+#define LV_KEY_LEFT      20
+#define LV_KEY_ESC       27
+#define LV_KEY_DEL       127
+#define LV_KEY_BACKSPACE 8
+#define LV_KEY_ENTER     10
+#define LV_KEY_NEXT      9
+#define LV_KEY_PREV      11
+#define LV_KEY_HOME      2
+#define LV_KEY_END       3
+
+#endif /* ZEPHYR_INCLUDE_DT_BINDINGS_LVGL_LVGL_H_ */

modules/lvgl/CMakeLists.txt

@@ -228,6 +228,7 @@ zephyr_library_sources_ifdef(CONFIG_LV_Z_POINTER_KSCAN  input/lvgl_pointer_kscan
 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_sources_ifdef(CONFIG_LV_Z_ENCODER_INPUT input/lvgl_encoder_input.c)
+zephyr_library_sources_ifdef(CONFIG_LV_Z_KEYPAD_INPUT input/lvgl_keypad_input.c)
 
 zephyr_library_link_libraries(LVGL)
 target_link_libraries(LVGL INTERFACE zephyr_interface)

modules/lvgl/Kconfig.input

@@ -77,4 +77,17 @@ config LV_Z_ENCODER_INPUT_MSGQ_COUNT
 	help
 	  Size of the encoder message queue buffering input events.
 
+config LV_Z_KEYPAD_INPUT
+	bool "Input lvgl keypad"
+	default y
+	depends on INPUT
+	depends on DT_HAS_ZEPHYR_LVGL_KEYPAD_INPUT_ENABLED
+
+config LV_Z_KEYPAD_INPUT_MSGQ_COUNT
+	int "Input keypad queue message count"
+	default 4
+	depends on LV_Z_KEYPAD_INPUT
+	help
+	  Size of the keypad message queue buffering input events.
+
 endmenu

modules/lvgl/include/lvgl_keypad_input.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 Fabian Blatz <fabianblatz@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_MODULES_LVGL_LVGL_KEYPAD_INPUT_H_
+#define ZEPHYR_MODULES_LVGL_LVGL_KEYPAD_INPUT_H_
+
+#include <zephyr/device.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int lvgl_keypad_input_init(const struct device *dev);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZEPHYR_MODULES_LVGL_LVGL_KEYPAD_INPUT_H_ */

modules/lvgl/input/lvgl_common_input.c

@@ -12,6 +12,7 @@
 #include "lvgl_pointer_input.h"
 #include "lvgl_button_input.h"
 #include "lvgl_encoder_input.h"
+#include "lvgl_keypad_input.h"
 
 LOG_MODULE_DECLARE(lvgl, CONFIG_LV_Z_LOG_LEVEL);
 
@@ -90,5 +91,9 @@ int lvgl_init_input_devices(void)
 				     lvgl_encoder_input_init);
 #endif /* CONFIG_LV_Z_ENCODER_INPUT */
 
+#ifdef CONFIG_LV_Z_KEYPAD_INPUT
+	DT_FOREACH_STATUS_OKAY_VARGS(zephyr_lvgl_keypad_input, LV_DEV_INIT, lvgl_keypad_input_init);
+#endif /* CONFIG_LV_Z_KEYPAD_INPUT */
+
 	return 0;
 }

modules/lvgl/input/lvgl_keypad_input.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2023 Fabian Blatz <fabianblatz@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT zephyr_lvgl_keypad_input
+
+#include "lvgl_common_input.h"
+#include "lvgl_keypad_input.h"
+#include <zephyr/sys/util.h>
+
+#include <zephyr/logging/log.h>
+
+LOG_MODULE_DECLARE(lvgl);
+
+struct lvgl_keypad_input_config {
+	struct lvgl_common_input_config common_config; /* Needs to be first member */
+	const uint16_t *input_codes;
+	const uint16_t *lvgl_codes;
+	uint8_t num_codes;
+};
+
+static void lvgl_keypad_process_event(const struct device *dev, struct input_event *evt)
+{
+	struct lvgl_common_input_data *data = dev->data;
+	const struct lvgl_keypad_input_config *cfg = dev->config;
+	uint8_t i;
+
+	for (i = 0; i < cfg->num_codes; i++) {
+		if (evt->code == cfg->input_codes[i]) {
+			data->pending_event.key = cfg->lvgl_codes[i];
+			break;
+		}
+	}
+
+	if (i == cfg->num_codes) {
+		LOG_WRN("Ignored input event: %u", evt->code);
+		return;
+	}
+
+	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 keypad queue");
+	}
+}
+
+int lvgl_keypad_input_init(const struct device *dev)
+{
+	return lvgl_input_register_driver(LV_INDEV_TYPE_KEYPAD, dev);
+}
+
+#define ASSERT_PROPERTIES(inst)                                                                    \
+	BUILD_ASSERT(DT_INST_PROP_LEN(inst, input_codes) == DT_INST_PROP_LEN(inst, lvgl_codes),    \
+		     "Property input-codes must have the same length as lvgl-codes.");
+
+#define LVGL_KEYPAD_INPUT_DEFINE(inst)                                                             \
+	ASSERT_PROPERTIES(inst);                                                                   \
+	LVGL_INPUT_DEFINE(inst, keypad, CONFIG_LV_Z_KEYPAD_INPUT_MSGQ_COUNT,                       \
+			  lvgl_keypad_process_event);                                              \
+	static const uint16_t lvgl_keypad_input_codes_##inst[] = DT_INST_PROP(inst, input_codes);  \
+	static const uint16_t lvgl_keypad_lvgl_codes_##inst[] = DT_INST_PROP(inst, lvgl_codes);    \
+	static const struct lvgl_keypad_input_config lvgl_keypad_input_config_##inst = {           \
+		.common_config.event_msgq = &LVGL_INPUT_EVENT_MSGQ(inst, keypad),                  \
+		.input_codes = lvgl_keypad_input_codes_##inst,                                     \
+		.lvgl_codes = lvgl_keypad_lvgl_codes_##inst,                                       \
+		.num_codes = DT_INST_PROP_LEN(inst, input_codes),                                  \
+	};                                                                                         \
+	static struct lvgl_common_input_data lvgl_common_input_data_##inst;                        \
+	DEVICE_DT_INST_DEFINE(inst, NULL, NULL, &lvgl_common_input_data_##inst,                    \
+			      &lvgl_keypad_input_config_##inst, POST_KERNEL,                       \
+			      CONFIG_INPUT_INIT_PRIORITY, NULL);
+
+DT_INST_FOREACH_STATUS_OKAY(LVGL_KEYPAD_INPUT_DEFINE)