// SPDX-License-Identifier: GPL-2.0
/*
* USB Raw Gadget driver.
* See Documentation/usb/raw-gadget.rst for more details.
*
* Copyright (c) 2020 Google, Inc.
* Author: Andrey Konovalov <andreyknvl@gmail.com>
*/
#include <linux/compiler.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/idr.h>
#include <linux/kref.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/semaphore.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include <linux/usb.h>
#include <linux/usb/ch9.h>
#include <linux/usb/ch11.h>
#include <linux/usb/gadget.h>
#include <linux/usb/composite.h>
#include <uapi/linux/usb/raw_gadget.h>
#define DRIVER_DESC "USB Raw Gadget"
#define DRIVER_NAME "raw-gadget"
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Andrey Konovalov");
MODULE_LICENSE("GPL");
/*----------------------------------------------------------------------*/
static DEFINE_IDA(driver_id_numbers);
#define DRIVER_DRIVER_NAME_LENGTH_MAX 32
#define RAW_EVENT_QUEUE_SIZE 16
struct raw_event_queue {
/* See the comment in raw_event_queue_fetch() for locking details. */
spinlock_t lock;
struct semaphore sema;
struct usb_raw_event *events[RAW_EVENT_QUEUE_SIZE];
int size;
};
static void raw_event_queue_init(struct raw_event_queue *queue)
{
spin_lock_init(&queue->lock);
sema_init(&queue->sema, 0);
queue->size = 0;
}
static int raw_event_queue_add(struct raw_event_queue *queue,
enum usb_raw_event_type type, size_t length, const void *data)
{
unsigned long flags;
struct usb_raw_event *event;
spin_lock_irqsave(&queue->lock, flags);
if (queue->size >= RAW_EVENT_QUEUE_SIZE) {
spin_unlock_irqrestore(&queue->lock, flags);
return -ENOMEM;
}
event = kmalloc(sizeof(*event) + length, GFP_ATOMIC);
if (!event) {
spin_unlock_irqrestore(&queue->lock, flags);
return -ENOMEM;
}
event->type = type;
event->length = length;
if (event->length)
memcpy(&event->data[0], data, length);
queue-&