Add support for MAX16150/MAX16169

Documentation/devicetree/bindings/input/adi,max16150.yaml

@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/adi,max16150.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices MAX16150/MAX16169 nanoPower Pushbutton On/Off Controller
+
+maintainers:
+  - Marc Paolo Sosa <[email protected]>
+
+description:
+  The MAX16150/MAX16169 is a low-power pushbutton on/off controller with a
+  switch debouncer and built-in latch. It accepts a noisy input from a
+  mechanical switch and produces a clean latched output, as well as a one-shot
+  interrupt output.
+
+properties:
+  compatible:
+    description:
+      Specifies the supported device variants. The MAX16150 and MAX16169 are supported.
+    enum:
+      - adi,max16150a
+      - adi,max16150b
+      - adi,max16169a
+      - adi,max16169b
+
+  interrupt-gpio:
+    maxItems: 1
+
+  clr-gpios:
+    description:
+      Clear Input. Pulling CLR low deasserts the latched OUT signal. If OUT is
+      already deasserted when CLR is pulled low, the state of OUT is unchanged.
+    maxItems: 1
+
+  linux,code:
+    default: KEY_POWER
+
+required:
+  - compatible
+  - interrupt-gpios
+  - clr-gpios
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/input/linux-event-codes.h>
+    #include <dt-bindings/gpio/gpio.h>
+
+    power-button {
+        compatible = "adi,max16150a";
+        interrupt-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>;
+        clr-gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
+        linux,code = <KEY_POWER>;
+    };

drivers/input/Kconfig.adi

@@ -15,3 +15,4 @@ config INPUT_ALL_ADI_DRIVERS
 	imply INPUT_AD714X
 	imply INPUT_AD714X_I2C
 	imply INPUT_AD714X_SPI
+	imply INPUT_MAX16150_PWRBUTTON

drivers/input/misc/Kconfig

@@ -150,6 +150,15 @@ config INPUT_E3X0_BUTTON
 	  To compile this driver as a module, choose M here: the
 	  module will be called e3x0_button.
 
+config INPUT_MAX16150_PWRBUTTON
+	tristate "MAX16150/MAX16169 Pushbutton driver"
+	help
+	  Say Y here if you want to enable power key reporting via
+	  MAX16150/MAX16169 nanoPower Pushbutton On/Off Controller.
+
+	  To compile this driver as a module, choose M here. The module will
+	  be called max16150.
+
 config INPUT_PCSPKR
 	tristate "PC Speaker support"
 	depends on PCSPKR_PLATFORM

drivers/input/misc/Makefile

@@ -49,6 +49,7 @@ obj-$(CONFIG_INPUT_IQS7222)		+= iqs7222.o
 obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o
 obj-$(CONFIG_INPUT_KXTJ9)		+= kxtj9.o
 obj-$(CONFIG_INPUT_M68K_BEEP)		+= m68kspkr.o
+obj-$(CONFIG_INPUT_MAX16150_PWRBUTTON)	+= max16150.o
 obj-$(CONFIG_INPUT_MAX77650_ONKEY)	+= max77650-onkey.o
 obj-$(CONFIG_INPUT_MAX77693_HAPTIC)	+= max77693-haptic.o
 obj-$(CONFIG_INPUT_MAX8925_ONKEY)	+= max8925_onkey.o

drivers/input/misc/max16150.c

@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Analog Devices MAX16150/MAX16169 Pushbutton Driver
+ *
+ * Copyright 2025 Analog Devices Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+
+#define MAX16150_LONG_INTERRUPT 120000000
+
+struct max16150_chip_info {
+	bool has_clr_gpio;
+};
+
+struct max16150_device {
+	struct input_dev *input;
+	struct gpio_desc *gpiod;
+	struct gpio_desc *clr_gpiod;
+	const struct max16150_chip_info *chip_info;
+	u64 low, high, duration;
+	unsigned int keycode;
+};
+
+static irqreturn_t max16150_irq_handler(int irq, void *_max16150)
+{
+	struct max16150_device *max16150 = _max16150;
+	int value;
+
+	value = gpiod_get_value(max16150->gpiod);
+
+	if (!value) {
+		max16150->low = ktime_get_ns();
+		return IRQ_HANDLED;
+	}
+
+	max16150->high = ktime_get_ns();
+	if (max16150->low) {
+		max16150->duration = max16150->high - max16150->low;
+
+		if (max16150->duration > MAX16150_LONG_INTERRUPT) {
+			gpiod_set_value(max16150->clr_gpiod, 1);
+			input_report_key(max16150->input, max16150->keycode, 1);
+			input_sync(max16150->input);
+			input_report_key(max16150->input, max16150->keycode, 0);
+			input_sync(max16150->input);
+		}
+
+		max16150->low = 0;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static const struct max16150_chip_info max16150_variant_a = {
+	.has_clr_gpio = true,
+};
+
+static const struct max16150_chip_info max16150_variant_b = {
+	.has_clr_gpio = false,
+};
+
+static int max16150_probe(struct platform_device *pdev)
+{
+	const struct max16150_chip_info *chip_info;
+	struct max16150_device *max16150;
+	struct device *dev = &pdev->dev;
+	int err, irq, ret;
+	u32 keycode;
+
+	chip_info = device_get_match_data(dev);
+	if (!chip_info)
+		return -EINVAL;
+
+	max16150 = devm_kzalloc(dev, sizeof(*max16150), GFP_KERNEL);
+	if (!max16150)
+		return -ENOMEM;
+
+	max16150->chip_info = chip_info;
+
+	max16150->input = devm_input_allocate_device(dev);
+	if (!max16150->input)
+		return -ENOMEM;
+
+	max16150->input->name = "MAX16150 Pushbutton";
+	max16150->input->phys = "max16150/input0";
+	max16150->input->id.bustype = BUS_HOST;
+
+	keycode = KEY_POWER;
+	ret = device_property_read_u32(dev, "linux,code", &keycode);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get keycode\n");
+
+	max16150->keycode = keycode;
+
+	input_set_capability(max16150->input, EV_KEY, max16150->keycode);
+
+	max16150->gpiod = devm_gpiod_get(dev, "interrupt", GPIOD_IN);
+	if (IS_ERR(max16150->gpiod))
+		return dev_err_probe(dev, PTR_ERR(max16150->gpiod),
+				     "Failed to get interrupt GPIO\n");
+
+	if (chip_info->has_clr_gpio) {
+		max16150->clr_gpiod = devm_gpiod_get(dev, "clr", GPIOD_OUT_HIGH);
+		if (IS_ERR(max16150->clr_gpiod))
+			return dev_err_probe(dev, PTR_ERR(max16150->clr_gpiod),
+					     "Failed to get clr GPIO\n");
+
+		if (!max16150->clr_gpiod)
+			return dev_err_probe(dev, -ENODEV,
+						 "clr GPIO is mandatory\n");
+
+		if (max16150->clr_gpiod) {
+			fsleep(1000);
+			gpiod_set_value(max16150->clr_gpiod, 0);
+		}
+	}
+
+	irq = gpiod_to_irq(max16150->gpiod);
+	if (irq < 0)
+		return dev_err_probe(dev, irq,
+				     "MAX16150: Failed to map GPIO to IRQ");
+
+	err = devm_request_irq(dev, irq, max16150_irq_handler,
+			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+			       "max16150_irq", max16150);
+	if (err)
+		return err;
+
+	return input_register_device(max16150->input);
+}
+
+static const struct of_device_id max16150_of_match[] = {
+	{ .compatible = "adi,max16150a", .data = &max16150_variant_a },
+	{ .compatible = "adi,max16150b", .data = &max16150_variant_b },
+	{ .compatible = "adi,max16169a", .data = &max16150_variant_a },
+	{ .compatible = "adi,max16169b", .data = &max16150_variant_b },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max16150_of_match);
+
+static struct platform_driver max16150_driver = {
+	.probe  = max16150_probe,
+	.driver = {
+		.name = "max16150",
+		.of_match_table = max16150_of_match,
+	},
+};
+module_platform_driver(max16150_driver);
+
+MODULE_AUTHOR("Marc Paolo Sosa <[email protected]>");
+MODULE_DESCRIPTION("MAX16150/MAX16169 Pushbutton Driver");
+MODULE_LICENSE("GPL");