mirror of
git://nv-tegra.nvidia.com/linux-nv-oot.git
synced 2025-12-22 17:25:35 +03:00
1267ce01fe
This driver exposes simple IOCTL that can be used for Perf measurement. Bug 4294493 Change-Id: I7a6cba710d9589da41f29e50ea487d8f9597f2db Signed-off-by: Bharat Nihalani <bnihalani@nvidia.com> Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/2991717 (cherry picked from commit ece89cb9c58c76fe822e8e80c99f671114d1b156) Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3002117 GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>
94 lines
2.0 KiB
C
94 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* SPDX-FileCopyrightText: Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/device.h>
|
|
#include <linux/cdev.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
/* Define IOCTL commands */
|
|
#define IOCTL_SET_VALUE _IOW('k', 1, int)
|
|
#define IOCTL_GET_VALUE _IOR('k', 2, int)
|
|
|
|
static int value;
|
|
static dev_t dev_num;
|
|
static struct cdev cdev;
|
|
static struct class *dev_class;
|
|
|
|
static int device_open(struct inode *inode, struct file *file)
|
|
{
|
|
pr_info("ioctl_example: Device opened\n");
|
|
return 0;
|
|
}
|
|
|
|
static int device_release(struct inode *inode, struct file *file)
|
|
{
|
|
pr_info("ioctl_example: Device closed\n");
|
|
return 0;
|
|
}
|
|
|
|
static long device_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
int ret = 0;
|
|
|
|
switch (cmd) {
|
|
case IOCTL_SET_VALUE:
|
|
if (copy_from_user(&value, (int *)arg, sizeof(int)))
|
|
ret = -EFAULT;
|
|
break;
|
|
|
|
case IOCTL_GET_VALUE:
|
|
if (copy_to_user((int *)arg, &value, sizeof(int)))
|
|
ret = -EFAULT;
|
|
break;
|
|
|
|
default:
|
|
ret = -ENOTTY;
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct file_operations fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = device_open,
|
|
.release = device_release,
|
|
.unlocked_ioctl = device_ioctl,
|
|
};
|
|
|
|
static int __init ioctl_example_init(void)
|
|
{
|
|
/* Allocate major and minor numbers */
|
|
alloc_chrdev_region(&dev_num, 0, 1, "ioctl_example");
|
|
|
|
/* Initialize the character device structure */
|
|
cdev_init(&cdev, &fops);
|
|
cdev_add(&cdev, dev_num, 1);
|
|
|
|
/* Create a device class */
|
|
dev_class = class_create(THIS_MODULE, "ioctl_example");
|
|
device_create(dev_class, NULL, dev_num, NULL, "ioctl_example");
|
|
|
|
pr_info("ioctl_example: Module loaded\n");
|
|
return 0;
|
|
}
|
|
|
|
static void __exit ioctl_example_exit(void)
|
|
{
|
|
device_destroy(dev_class, dev_num);
|
|
class_destroy(dev_class);
|
|
cdev_del(&cdev);
|
|
unregister_chrdev_region(dev_num, 1);
|
|
pr_info("ioctl_example: Module unloaded\n");
|
|
}
|
|
|
|
module_init(ioctl_example_init);
|
|
module_exit(ioctl_example_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("Simple IOCTL Example");
|
|
|