linux-imx

// SPDX-License-Identifier: GPL-2.0+

/*

 * HID driver for Valve Steam Controller

 *

 * Copyright (c) 2018 Rodrigo Rivas Costa <rodrigorivascosta@gmail.com>

 *

 * Supports both the wired and wireless interfaces.

 *

 * This controller has a builtin emulation of mouse and keyboard: the right pad

 * can be used as a mouse, the shoulder buttons are mouse buttons, A and B

 * buttons are ENTER and ESCAPE, and so on. This is implemented as additional

 * HID interfaces.

 *

 * This is known as the "lizard mode", because apparently lizards like to use

 * the computer from the coach, without a proper mouse and keyboard.

 *

 * This driver will disable the lizard mode when the input device is opened

 * and re-enable it when the input device is closed, so as not to break user

 * mode behaviour. The lizard_mode parameter can be used to change that.

 *

 * There are a few user space applications (notably Steam Client) that use

 * the hidraw interface directly to create input devices (XTest, uinput...).

 * In order to avoid breaking them this driver creates a layered hidraw device,

 * so it can detect when the client is running and then:

 *  - it will not send any command to the controller.

 *  - this input device will be removed, to avoid double input of the same

 *    user action.

 * When the client is closed, this input device will be created again.

 *

 * For additional functions, such as changing the right-pad margin or switching

 * the led, you can use the user-space tool at:

 *

 *   https://github.com/rodrigorc/steamctrl

 */

​

#include <linux/device.h>

#include <linux/input.h>

#include <linux/hid.h>

#include <linux/module.h>

#include <linux/workqueue.h>

#include <linux/mutex.h>

#include <linux/rcupdate.h>

#include <linux/delay.h>

#include <linux/power_supply.h>

#include "hid-ids.h"

​

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Rodrigo Rivas Costa <rodrigorivascosta@gmail.com>");

​

static bool lizard_mode = true;

​

static DEFINE_MUTEX(steam_devices_lock);

static LIST_HEAD(steam_devices);

​

#define STEAM_QUIRK_WIRELESS        BIT(0)

​

/* Touch pads are 40 mm in diameter and 65535 units */

#define STEAM_PAD_RESOLUTION 1638

/* Trigger runs are about 5 mm and 256 units */

#define STEAM_TRIGGER_RESOLUTION 51

/* Joystick runs are about 5 mm and 256 units */

#define STEAM_JOYSTICK_RESOLUTION 51

​