From 2dc6f7518861ba5ec95a798149b8ea8ed12cd0f9 Mon Sep 17 00:00:00 2001
From: Marc Paolo Sosa <marcpaolo.sosa@analog.com>
Date: Thu, 5 Dec 2024 10:38:31 +0800
Subject: [PATCH] input: misc: add driver for max16150

MAX16150/MAX16169 nanoPower Pushbutton On/Off Controller

Signed-off-by: Marc Paolo Sosa <marcpaolo.sosa@analog.com>
---
 drivers/input/misc/Kconfig    |  9 ++++
 drivers/input/misc/Makefile   |  1 +
 drivers/input/misc/max16150.c | 93 +++++++++++++++++++++++++++++++++++
 3 files changed, 103 insertions(+)
 create mode 100644 drivers/input/misc/max16150.c

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 6ba984d7f0b18..e4c3dd4cd2275 100644
--- a/drivers/input/misc/Kconfig
+++ b/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
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 04296a4abe8e8..92b57e9522086 100644
--- a/drivers/input/misc/Makefile
+++ b/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
diff --git a/drivers/input/misc/max16150.c b/drivers/input/misc/max16150.c
new file mode 100644
index 0000000000000..1d6a47fa21814
--- /dev/null
+++ b/drivers/input/misc/max16150.c
@@ -0,0 +1,93 @@
+// 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>
+
+#define GPIO_INT 17
+#define GPIO_CLR 27
+
+static struct input_dev *max16150_input_dev;
+static int irq_number;
+static ktime_t last_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 = ktime_sub(now, last_time);
+
+	if (duration >= long_pulse)
+		gpio_set_value(GPIO_CLR, 0);
+
+	last_time = now;
+	return IRQ_HANDLED;
+}
+
+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 power button\n");
+		return -ENOMEM;
+	}
+
+	button->name = "max16150";
+	button->phys = "max16150/input0";
+	button->id.bustype = BUS_HOST;
+	input_set_capability(button, EV_KEY, KEY_POWER);
+
+	ret = input_register_device(button);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't register power button: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_gpio_request_one(&pdev->dev, GPIO_CLR, GPIOF_OUT_INIT_HIGH,
+				    "max16150_clr");
+	if (ret)
+		return ret;
+
+	irq_number = gpio_to_irq(GPIO_INT);
+	ret = devm_request_irq(&pdev->dev, irq_number, max16150_isr,
+			       IRQF_TRIGGER_RISING, "max16150_irq", NULL);
+	if (ret)
+		return ret;
+
+	last_time = ktime_get();
+	platform_set_drvdata(pdev, button);
+	device_init_wakeup(&pdev->dev, true);
+
+	return 0;
+}
+
+static int max16150_remove(struct platform_device *pdev)
+{
+	input_unregister_device(max16150_input_dev);
+	return 0;
+}
+
+static struct platform_driver max16150_driver = {
+	.probe = max16150_probe,
+	.remove = max16150_remove,
+	.driver = {
+		.name = "max16150",
+	},
+};
+
+module_platform_driver(max16150_driver);
+
+MODULE_AUTHOR("Marc Paolo Sosa <marcpaolo.sosa@analog.com>");
+MODULE_DESCRIPTION("MAX16150/MAX16169 Pushbutton Driver");
+MODULE_LICENSE("GPL");