path: root/drivers/usb/gadget/function/f_hid.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * f_hid.c -- USB HID function driver
 *
 * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/hid.h>
#include <linux/idr.h>
#include <linux/cdev.h>
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/usb/g_hid.h>

#include "u_f.h"
#include "u_hid.h"

#define HIDG_MINORS	4

static int major, minors;
static struct class *hidg_class;
static DEFINE_IDA(hidg_ida);
static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */

/*-------------------------------------------------------------------------*/
/*                            HID gadget struct                            */

struct f_hidg_req_list {
	struct usb_request	*req;
	unsigned int		pos;
	struct list_head 	list;
};

struct f_hidg {
	/* configuration */
	unsigned char			bInterfaceSubClass;
	unsigned char			bInterfaceProtocol;
	unsigned char			protocol;
	unsigned char			idle;
	unsigned short			report_desc_length;
	char				*report_desc;
	unsigned short			report_length;
	/*
	 * use_out_ep - if true, the OUT Endpoint (interrupt out method)
	 *              will be used to receive reports from the host
	 *              using functions with the "intout" suffix.
	 *              Otherwise, the OUT Endpoint will not be configured
	 *              and the SETUP/SET_REPORT method ("ssreport" suffix)
	 *              will be used to receive reports.
	 */
	bool				use_out_ep;

	/* recv report */
	spinlock_t			read_spinlock;
	wait_queue_head_t		read_queue;
	/* recv report - interrupt out only (use_out_ep == 1) */
	struct list_head		completed_out_req;
	unsigned int			qlen;
	/* recv report - setup set_report only (use_out_ep == 0) */
	char				*set_report_buf;
	unsigned int			set_report_length;

	/* send report */
	spinlock_t			write_spinlock;
	bool				write_pending;
	wait_queue_head_t		write_queue;
	struct usb_request		*req;

	int				minor;
	struct cdev			cdev;
	struct usb_function		func;

	struct usb_ep			*in_ep;
	struct usb_ep			*out_ep;
};

static inline struct f_hidg *func_to_hidg(struct usb_function