drivers/input/mouse/amimouse.c

Source file repositories/reference/linux-study-clean/drivers/input/mouse/amimouse.c

File Facts

System
Linux kernel
Corpus path
drivers/input/mouse/amimouse.c
Extension
.c
Size
3462 bytes
Lines
151
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
/*
 *  Amiga mouse driver for Linux/m68k
 *
 *  Copyright (c) 2000-2002 Vojtech Pavlik
 *
 *  Based on the work of:
 *	Michael Rausch		James Banks
 *	Matther Dillon		David Giller
 *	Nathan Laredo		Linus Torvalds
 *	Johan Myreen		Jes Sorensen
 *	Russell King
 */


#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

#include <asm/irq.h>
#include <asm/setup.h>
#include <linux/uaccess.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Amiga mouse driver");
MODULE_LICENSE("GPL");

static int amimouse_lastx, amimouse_lasty;

static irqreturn_t amimouse_interrupt(int irq, void *data)
{
	struct input_dev *dev = data;
	unsigned short joy0dat, potgor;
	int nx, ny, dx, dy;

	joy0dat = amiga_custom.joy0dat;

	nx = joy0dat & 0xff;
	ny = joy0dat >> 8;

	dx = nx - amimouse_lastx;
	dy = ny - amimouse_lasty;

	if (dx < -127) dx = (256 + nx) - amimouse_lastx;
	if (dx >  127) dx = (nx - 256) - amimouse_lastx;
	if (dy < -127) dy = (256 + ny) - amimouse_lasty;
	if (dy >  127) dy = (ny - 256) - amimouse_lasty;

	amimouse_lastx = nx;
	amimouse_lasty = ny;

	potgor = amiga_custom.potgor;

	input_report_rel(dev, REL_X, dx);
	input_report_rel(dev, REL_Y, dy);

	input_report_key(dev, BTN_LEFT,   ciaa.pra & 0x40);
	input_report_key(dev, BTN_MIDDLE, potgor & 0x0100);
	input_report_key(dev, BTN_RIGHT,  potgor & 0x0400);

	input_sync(dev);

	return IRQ_HANDLED;
}

static int amimouse_open(struct input_dev *dev)
{
	unsigned short joy0dat;
	int error;

	joy0dat = amiga_custom.joy0dat;

	amimouse_lastx = joy0dat & 0xff;
	amimouse_lasty = joy0dat >> 8;

	error = request_irq(IRQ_AMIGA_VERTB, amimouse_interrupt, 0, "amimouse",
			    dev);
	if (error)
		dev_err(&dev->dev, "Can't allocate irq %d\n", IRQ_AMIGA_VERTB);

	return error;
}

static void amimouse_close(struct input_dev *dev)
{
	free_irq(IRQ_AMIGA_VERTB, dev);

Annotation

Implementation Notes