Input: add support for NI Ettus Research USRP E3x0 button

Signed-off-by: Moritz Fischer <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

Documentation/devicetree/bindings/input/e3x0-button.txt

···
+National Instruments Ettus Research USRP E3x0 button driver
+
+This module is part of the NI Ettus Research USRP E3x0 SDR.
+
+This module provides a simple power button event via two interrupts.
+
+Required properties:
+- compatible: should be one of the following
+  - "ettus,e3x0-button": For devices such as the NI Ettus Research USRP E3x0
+- interrupt-parent:
+  - a phandle to the interrupt controller that it is attached to.
+- interrupts: should be one of the following
+  - <0 30 1>, <0 31 1>: For devices such as the NI Ettus Research USRP E3x0
+- interrupt-names: should be one of the following
+  - "press", "release": For devices such as the NI Ettus Research USRP E3x0
+
+Note: Interrupt numbers might vary depending on the FPGA configuration.
+
+Example:
+	button {
+		compatible = "ettus,e3x0-button";
+		interrupt-parent = <&intc>;
+		interrupts = <0 30 1>, <0 31 1>;
+		interrupt-names = "press", "release";
+	}

Documentation/devicetree/bindings/vendor-prefixes.txt

···
 epfl	Ecole Polytechnique Fédérale de Lausanne
 epson	Seiko Epson Corp.
 est	ESTeem Wireless Modems
+ettus	NI Ettus Research
 eukrea  Eukréa Electromatique
 excito	Excito
 fsl	Freescale Semiconductor

drivers/input/misc/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called bma150.
 
+config INPUT_E3X0_BUTTON
+	tristate "NI Ettus Research USRP E3x0 Button support."
+	default n
+	help
+	  Say Y here to enable support for the NI Ettus Research
+	  USRP E3x0 Button.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called e3x0_button.
+
 config INPUT_PCSPKR
 	tristate "PC Speaker support"
 	depends on PCSPKR_PLATFORM

drivers/input/misc/Makefile

···
 obj-$(CONFIG_INPUT_DA9052_ONKEY)	+= da9052_onkey.o
 obj-$(CONFIG_INPUT_DA9055_ONKEY)	+= da9055_onkey.o
 obj-$(CONFIG_INPUT_DM355EVM)		+= dm355evm_keys.o
+obj-$(CONFIG_INPUT_E3X0_BUTTON)		+= e3x0-button.o
 obj-$(CONFIG_INPUT_DRV260X_HAPTICS)	+= drv260x.o
 obj-$(CONFIG_INPUT_DRV2667_HAPTICS)	+= drv2667.o
 obj-$(CONFIG_INPUT_GP2A)		+= gp2ap002a00f.o

drivers/input/misc/e3x0-button.c

···
+/*
+ * Copyright (c) 2014, National Instruments Corp. All rights reserved.
+ *
+ * Driver for NI Ettus Research USRP E3x0 Button Driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+static irqreturn_t e3x0_button_release_handler(int irq, void *data)
+{
+	struct input_dev *idev = data;
+
+	input_report_key(idev, KEY_POWER, 0);
+	input_sync(idev);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t e3x0_button_press_handler(int irq, void *data)
+{
+	struct input_dev *idev = data;
+
+	input_report_key(idev, KEY_POWER, 1);
+	pm_wakeup_event(idev->dev.parent, 0);
+	input_sync(idev);
+
+	return IRQ_HANDLED;
+}
+
+static int __maybe_unused e3x0_button_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(platform_get_irq_byname(pdev, "press"));
+
+	return 0;
+}
+
+static int __maybe_unused e3x0_button_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(platform_get_irq_byname(pdev, "press"));
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(e3x0_button_pm_ops,
+			 e3x0_button_suspend, e3x0_button_resume);
+
+static int e3x0_button_probe(struct platform_device *pdev)
+{
+	struct input_dev *input;
+	int irq_press, irq_release;
+	int error;
+
+	irq_press = platform_get_irq_byname(pdev, "press");
+	if (irq_press < 0) {
+		dev_err(&pdev->dev, "No IRQ for 'press', error=%d\n",
+			irq_press);
+		return irq_press;
+	}
+
+	irq_release = platform_get_irq_byname(pdev, "release");
+	if (irq_release < 0) {
+		dev_err(&pdev->dev, "No IRQ for 'release', error=%d\n",
+			irq_release);
+		return irq_release;
+	}
+
+	input = devm_input_allocate_device(&pdev->dev);
+	if (!input)
+		return -ENOMEM;
+
+	input->name = "NI Ettus Research USRP E3x0 Button Driver";
+	input->phys = "e3x0_button/input0";
+	input->dev.parent = &pdev->dev;
+
+	input_set_capability(input, EV_KEY, KEY_POWER);
+
+	error = devm_request_irq(&pdev->dev, irq_press,
+				 e3x0_button_press_handler, 0,
+				 "e3x0-button", input);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to request 'press' IRQ#%d: %d\n",
+			irq_press, error);
+		return error;
+	}
+
+	error = devm_request_irq(&pdev->dev, irq_release,
+				 e3x0_button_release_handler, 0,
+				 "e3x0-button", input);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to request 'release' IRQ#%d: %d\n",
+			irq_release, error);
+		return error;
+	}
+
+	error = input_register_device(input);
+	if (error) {
+		dev_err(&pdev->dev, "Can't register input device: %d\n", error);
+		return error;
+	}
+
+	platform_set_drvdata(pdev, input);
+	device_init_wakeup(&pdev->dev, 1);
+	return 0;
+}
+
+static int e3x0_button_remove(struct platform_device *pdev)
+{
+	device_init_wakeup(&pdev->dev, 0);
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id e3x0_button_match[] = {
+	{ .compatible = "ettus,e3x0-button", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, e3x0_button_match);
+#endif
+
+static struct platform_driver e3x0_button_driver = {
+	.driver		= {
+		.name	= "e3x0-button",
+		.of_match_table = of_match_ptr(e3x0_button_match),
+		.pm	= &e3x0_button_pm_ops,
+	},
+	.probe		= e3x0_button_probe,
+	.remove		= e3x0_button_remove,
+};
+
+module_platform_driver(e3x0_button_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Moritz Fischer <[e-mail]>");
+MODULE_DESCRIPTION("NI Ettus Research USRP E3x0 Button driver");
+MODULE_ALIAS("platform:e3x0-button");