Add seesaw keypad

Signed-off-by: Titouan Christophe <[email protected]>

Author: titouanc

drivers/input/CMakeLists.txt

@@ -31,6 +31,7 @@ zephyr_library_sources_ifdef(CONFIG_INPUT_PINNACLE input_pinnacle.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_PMW3610 input_pmw3610.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_REALTEK_RTS5912_KBD input_realtek_rts5912_kbd.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_SBUS input_sbus.c)
+zephyr_library_sources_ifdef(CONFIG_INPUT_SEESAW_KEYPAD input_seesaw_keypad.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_STM32_TSC_KEYS input_tsc_keys.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_STMPE811 input_stmpe811.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_TOUCH input_touch.c)

drivers/input/Kconfig

@@ -34,6 +34,7 @@ source "drivers/input/Kconfig.pmw3610"
 source "drivers/input/Kconfig.rts5912"
 source "drivers/input/Kconfig.sbus"
 source "drivers/input/Kconfig.sdl"
+source "drivers/input/Kconfig.seesaw_keypad"
 source "drivers/input/Kconfig.stmpe811"
 source "drivers/input/Kconfig.touch"
 source "drivers/input/Kconfig.tsc_keys"

drivers/input/Kconfig.seesaw_keypad

@@ -0,0 +1,18 @@
+# Copyright (c) 2025 Titouan Christophe
+# SPDX-License-Identifier: Apache-2.0
+
+config INPUT_SEESAW_KEYPAD
+	bool "Adafruit seesaw keypad over I2C"
+	default y
+	depends on DT_HAS_ADAFRUIT_SEESAW_KEYPAD_ENABLED
+	depends on MFD_SEESAW
+	help
+	  Enable support for Adafruit Seesaw gpio
+
+if INPUT_SEESAW_KEYPAD
+
+config INPUT_SEESAW_KEYPAD_POLL_INTERVAL
+	int "Event poll interval (ms)"
+	default 25
+
+endif

drivers/input/input_seesaw_keypad.c

@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2025 Titouan Christophe
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT adafruit_seesaw_keypad
+
+#include <zephyr/input/input.h>
+#include <zephyr/drivers/mfd/mfd_seesaw.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(seesaw_keypad, CONFIG_MFD_SEESAW_LOG_LEVEL);
+
+enum {
+	KEYPAD_STATUS = 0x00,
+	KEYPAD_EVENT = 0x01,
+	KEYPAD_INTENSET = 0x02,
+	KEYPAD_INTENCLR = 0x03,
+	KEYPAD_COUNT = 0x04,
+	KEYPAD_FIFO = 0x10,
+};
+
+enum key_edge {
+	EDGE_HIGH = 0,
+	EDGE_LOW = 1,
+	EDGE_FALLING = 2,
+	EDGE_RISING = 3,
+};
+
+struct seesaw_keypad_config {
+	const struct device *seesaw;
+};
+
+struct seesaw_keypad_data {
+	const struct device *dev;
+	struct k_work_delayable work;
+};
+
+static int seesaw_keypad_get_event(const struct device *dev)
+{
+	const struct seesaw_keypad_config *config = dev->config;
+	uint8_t keypad_event;
+	int ret = seesaw_read(config->seesaw, SEESAW_MOD_KEYPAD, KEYPAD_FIFO, &keypad_event, 1);
+
+	if (ret < 0) {
+		LOG_ERR("Error polling events FIFO: %d", ret);
+		return ret;
+	}
+
+	if (keypad_event == 0xff) {
+		/* Reached end of FIFO */
+		return 0;
+	}
+
+	input_report(dev, INPUT_EV_KEY, (keypad_event >> 2), (keypad_event & 1), true, K_NO_WAIT);
+	return 1;
+}
+
+static void seesaw_keypad_poll(struct k_work *work)
+{
+	struct k_work_delayable *dwork = k_work_delayable_from_work(work);
+	struct seesaw_keypad_data *drv_data = CONTAINER_OF(dwork, struct seesaw_keypad_data, work);
+
+	while (seesaw_keypad_get_event(drv_data->dev) > 0) {
+		continue;
+	}
+
+	k_work_reschedule(dwork, K_MSEC(CONFIG_INPUT_SEESAW_KEYPAD_POLL_INTERVAL));
+}
+
+static int seesaw_keypad_init(const struct device *dev)
+{
+	int ret;
+	struct seesaw_keypad_data *drv_data = dev->data;
+	const struct seesaw_keypad_config *config = dev->config;
+	/* Enable RISE/FALL events on all keys */
+	uint8_t edges = BIT(EDGE_RISING) | BIT(EDGE_FALLING);
+
+	ret = seesaw_claim_module(config->seesaw, SEESAW_MOD_KEYPAD, dev);
+	if (ret) {
+		return ret;
+	}
+
+	drv_data->dev = dev;
+	k_work_init_delayable(&drv_data->work, seesaw_keypad_poll);
+
+	for (int i = 0; i < 16; i++) {
+		uint8_t buf[] = {
+			(i & 0xc) << 1 | (i & 0x03),
+			(edges << 1) | 1,
+		};
+
+		ret = seesaw_write(config->seesaw, SEESAW_MOD_KEYPAD, KEYPAD_EVENT,
+				   buf, sizeof(buf));
+		if (ret) {
+			LOG_ERR("Unable to configure keypad event: %d", ret);
+			return ret;
+		}
+	}
+
+	k_work_reschedule(&drv_data->work, K_MSEC(CONFIG_INPUT_SEESAW_KEYPAD_POLL_INTERVAL));
+	LOG_DBG("%s initialized", dev->name);
+
+	return 0;
+}
+
+#define SEESAW_KEYPAD_INIT(inst)                                                                   \
+	static struct seesaw_keypad_data data_##inst;                                              \
+	static const struct seesaw_keypad_config config_##inst = {                                 \
+		.seesaw = DEVICE_DT_GET(DT_INST_PARENT(inst)),                                     \
+	};                                                                                         \
+	DEVICE_DT_INST_DEFINE(inst, seesaw_keypad_init, NULL, &data_##inst, &config_##inst,        \
+				  POST_KERNEL, CONFIG_MFD_INIT_PRIORITY, NULL);
+
+DT_INST_FOREACH_STATUS_OKAY(SEESAW_KEYPAD_INIT)

dts/bindings/input/adafruit,seesaw-keypad.yaml

@@ -0,0 +1,6 @@
+# Copyright (c) 2025 Titouan Christophe
+# SPDX-License-Identifier: Apache-2.0
+
+description: Adafruit Seesaw keypad input
+
+compatible: "adafruit,seesaw-keypad"