drivers/input/misc/e3x0-button.c

Source file repositories/reference/linux-study-clean/drivers/input/misc/e3x0-button.c

File Facts

System
Linux kernel
Corpus path
drivers/input/misc/e3x0-button.c
Extension
.c
Size
3213 bytes
Lines
136
Domain
Driver Families
Bucket
drivers/input
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2014, National Instruments Corp. All rights reserved.
 *
 * Driver for NI Ettus Research USRP E3x0 Button Driver
 */

#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 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 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 DEFINE_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)
		return irq_press;

	irq_release = platform_get_irq_byname(pdev, "release");
	if (irq_release < 0)
		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);

Annotation

Implementation Notes