Add support for MAX16150/MAX16169

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

@@ -0,0 +1,56 @@
+# 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 an extremely low-power, pushbutton, on/off controller
+  with a switch debouncer and built-in latch. This device accepts a noisy input
+  from a mechanical switch and produces a clean, latched output, as well as a
+  one-shot interrupt output, in response to a switch closure exceeding the
+  debounce period at PB_IN. A switch closure longer than the shutdown period at
+  PB_IN results in a longer one-shot interrupt output. The MAX16150 family has
+  two sets of devices, one in which a longer switch closure greater than the
+  shutdown period deasserts the latched output, and another in which the latched
+  output stays asserted.
+
+  Specifications about the controller can be found at:
+    https://www.analog.com/en/products/max16150.html
+    https://www.analog.com/en/products/max16169.html
+
+properties:
+  compatible:
+    enum:
+      - adi,max16150
+      - adi,max16169
+
+required:
+  - compatible
+  - gpios
+  - interrupt-parent
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    gpio {
+        max16150_pins: max16150_pins {
+            pins = <17>;
+            function = <0>;
+        };
+    };
+
+    power-button {
+        compatible = "adi,max16150";
+        gpios = <&gpio 17 0>;
+        interrupt-parent = <&gpio>;
+        interrupts = <17 2>;
+        status = "okay";
+    };

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
+	bool "MAX16150/MAX16169 Pushbutton driver"
+	depends on OF_GPIO
+	help
+	  This driver supports the MAX16150 and MAX16169 pushbutton
+	  controllers, which are low-power devices with a switch
+	  debouncer and built-in latch. Device bindings are specified
+	  in the device tree.
+
 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 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Analog Devices MAX16150/MAX16169 Pushbutton Driver
+ *
+ * Copyright 2024 Analog Devices Inc.
+ */
+
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/platform_device.h>
+#include <linux/of_gpio.h>
+#include <linux/of_device.h>
+
+static int irq_number;
+static ktime_t prev_time;
+static const ktime_t short_pulse = 32 * NSEC_PER_MSEC;
+static const ktime_t long_pulse = 128 * NSEC_PER_MSEC;
+
+static irqreturn_t max16150_isr(int irq, void *dev_id)
+{
+	ktime_t now = ktime_get();
+	ktime_t duration;
+	struct input_dev *button = dev_id;
+	static bool falling_edge = false;
+
+	if (gpio_get_value(irq) == 0) {
+		prev_time = now;
+		falling_edge = true;
+	} else if (falling_edge) {
+		duration = ktime_sub(now, prev_time);
+		if (duration >= long_pulse)
+			input_report_key(button, KEY_POWER, 1);
+		else
+			input_report_key(button, KEY_WAKEUP, 1);
+
+		input_sync(button);
+		falling_edge = false;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int get_irq(struct platform_device *pdev)
+{
+	return platform_get_irq(pdev, 0);
+}
+
+static int max16150_probe(struct platform_device *pdev)
+{
+	struct input_dev *button;
+	int ret;
+
+	button = devm_input_allocate_device(&pdev->dev);
+	if (!button) {
+		dev_err(&pdev->dev, "Can't allocate input device\n");
+		return -ENOMEM;
+	}
+
+	button->name = "max16150";
+	button->phys = "max16150/input0";
+	button->id.bustype = BUS_HOST;
+	input_set_capability(button, EV_KEY, KEY_POWER);
+	input_set_capability(button, EV_KEY, KEY_WAKEUP);
+
+	ret = input_register_device(button);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't register input device: %d\n", ret);
+		return ret;
+	}
+
+	irq_number = get_irq(pdev);
+	if (irq_number < 0) {
+		dev_err(&pdev->dev, "Can't get IRQ\n");
+		return irq_number;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq_number, max16150_isr,
+			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, "max16150_irq", button);
+	if (ret)
+		return ret;
+
+	prev_time = ktime_get();
+	platform_set_drvdata(pdev, button);
+	device_init_wakeup(&pdev->dev, true);
+
+	return 0;
+}
+
+static int max16150_remove(struct platform_device *pdev)
+{
+	struct input_dev *button = platform_get_drvdata(pdev);
+
+	input_unregister_device(button);
+	return 0;
+}
+
+static const struct of_device_id max16150_of_match[] = {
+	{ .compatible = "adi,max16150" },
+	{ .compatible = "adi,max16169" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max16150_of_match);
+
+static struct platform_driver max16150_driver = {
+	.probe = max16150_probe,
+	.remove = max16150_remove,
+	.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");