linux-imx

/*

 * Roccat driver for Linux

 *

 * Copyright (c) 2010 Stefan Achatz <erazor_de@users.sourceforge.net>

 */

​

/*

 * 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; either version 2 of the License, or (at your option)

 * any later version.

 */

​

/*

 * Module roccat is a char device used to report special events of roccat

 * hardware to userland. These events include requests for on-screen-display of

 * profile or dpi settings or requests for execution of macro sequences that are

 * not stored in device. The information in these events depends on hid device

 * implementation and contains data that is not available in a single hid event

 * or else hidraw could have been used.

 * It is inspired by hidraw, but uses only one circular buffer for all readers.

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/cdev.h>

#include <linux/poll.h>

#include <linux/sched/signal.h>

#include <linux/hid-roccat.h>

#include <linux/module.h>

​

#define ROCCAT_FIRST_MINOR 0

#define ROCCAT_MAX_DEVICES 8

​

/* should be a power of 2 for performance reason */

#define ROCCAT_CBUF_SIZE 16

​

struct roccat_report {

    uint8_t *value;

};

​

struct roccat_device {

    unsigned int minor;

    int report_size;

    int open;

    int exist;

    wait_queue_head_t wait;

    struct device *dev;

    struct hid_device *hid;

    struct list_head readers;

    /* protects modifications of readers list */

    struct mutex readers_lock;

​

    /*

     * circular_buffer has one writer and multiple readers with their own

     * read pointers

     */

    struct roccat_report cbuf[ROCCAT_CBUF_SIZE];

    int cbuf_end;

    struct mutex cbuf_lock;

};

​

struct roccat_reader {