drivers/macintosh/ams/ams-input.c

Source file repositories/reference/linux-study-clean/drivers/macintosh/ams/ams-input.c

File Facts

System
Linux kernel
Corpus path
drivers/macintosh/ams/ams-input.c
Extension
.c
Size
3210 bytes
Lines
157
Domain
Driver Families
Bucket
drivers/macintosh
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-or-later
/*
 * Apple Motion Sensor driver (joystick emulation)
 *
 * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
 */

#include <linux/module.h>

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/delay.h>

#include "ams.h"

static bool joystick;
module_param(joystick, bool, S_IRUGO);
MODULE_PARM_DESC(joystick, "Enable the input class device on module load");

static bool invert;
module_param(invert, bool, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(invert, "Invert input data on X and Y axis");

static DEFINE_MUTEX(ams_input_mutex);

static void ams_idev_poll(struct input_dev *idev)
{
	s8 x, y, z;

	mutex_lock(&ams_info.lock);

	ams_sensors(&x, &y, &z);

	x -= ams_info.xcalib;
	y -= ams_info.ycalib;
	z -= ams_info.zcalib;

	input_report_abs(idev, ABS_X, invert ? -x : x);
	input_report_abs(idev, ABS_Y, invert ? -y : y);
	input_report_abs(idev, ABS_Z, z);

	input_sync(idev);

	mutex_unlock(&ams_info.lock);
}

/* Call with ams_info.lock held! */
static int ams_input_enable(void)
{
	struct input_dev *input;
	s8 x, y, z;
	int error;

	ams_sensors(&x, &y, &z);
	ams_info.xcalib = x;
	ams_info.ycalib = y;
	ams_info.zcalib = z;

	input = input_allocate_device();
	if (!input)
		return -ENOMEM;

	input->name = "Apple Motion Sensor";
	input->id.bustype = ams_info.bustype;
	input->id.vendor = 0;
	input->dev.parent = &ams_info.of_dev->dev;

	input_set_abs_params(input, ABS_X, -50, 50, 3, 0);
	input_set_abs_params(input, ABS_Y, -50, 50, 3, 0);
	input_set_abs_params(input, ABS_Z, -50, 50, 3, 0);
	input_set_capability(input, EV_KEY, BTN_TOUCH);

	error = input_setup_polling(input, ams_idev_poll);
	if (error)
		goto err_free_input;

	input_set_poll_interval(input, 25);

	error = input_register_device(input);
	if (error)
		goto err_free_input;

	ams_info.idev = input;
	joystick = true;

	return 0;

err_free_input:

Annotation

Implementation Notes