From b8e5f60912c77d52214c21e67fa91ec5f522c54c Mon Sep 17 00:00:00 2001
From: guowenxue <guowenxue@gmail.com>
Date: Mon, 23 Dec 2024 16:33:12 +0800
Subject: [PATCH] Update x86 example driver
---
bsp/drivers/x86/driver/chrdev3.c | 150 +++++++++++++++++---------------------------------
1 files changed, 51 insertions(+), 99 deletions(-)
diff --git a/bsp/drivers/x86_64/ldd3_ioctl.c b/bsp/drivers/x86/driver/chrdev3.c
similarity index 62%
copy from bsp/drivers/x86_64/ldd3_ioctl.c
copy to bsp/drivers/x86/driver/chrdev3.c
index 295808d..1b4777b 100644
--- a/bsp/drivers/x86_64/ldd3_ioctl.c
+++ b/bsp/drivers/x86/driver/chrdev3.c
@@ -1,50 +1,31 @@
+/*
+ * Copyright (C) 2024 LingYun IoT System Studio
+ * Author: Guo Wenxue <guowenxue@gmail.com>
+ *
+ * A character skeleton driver example in linux kernel.
+ */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h> /* printk() */
-#include <linux/slab.h> /* kmalloc() */
#include <linux/fs.h> /* everything... */
#include <linux/errno.h> /* error codes */
#include <linux/types.h> /* size_t */
#include <linux/cdev.h> /* cdev */
-#include <linux/fcntl.h> /* O_ACCMODE */
-#include <linux/uaccess.h> /* copy_*_user */
+#include <linux/slab.h> /* kmalloc() */
#include <linux/version.h> /* kernel version code */
+#include <linux/uaccess.h> /* copy_from/to_user() */
#include <linux/moduleparam.h>
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(5,0,0)
-#define access_ok_wrapper(type,arg,cmd) access_ok(type, arg, cmd)
-#else
-#define access_ok_wrapper(type,arg,cmd) access_ok(arg, cmd)
-#endif
-
-/* ioctl definitions, use 'z' as magic number */
-#define CHRDEV_IOC_MAGIC 'z'
-#define CHRDEV_IOCRESET _IO(CHRDEV_IOC_MAGIC, 0)
-#define CHRDEV_IOCSET _IOW(CHRDEV_IOC_MAGIC, 1, int)
-#define CHRDEV_IOCGET _IOR(CHRDEV_IOC_MAGIC, 2, int)
-#define CHRDEV_IOC_MAXNR 3
/* device name and major number */
#define DEV_NAME "chrdev"
-#define DEV_SIZE 1024
-#define CONFIG_AUTODEV 1 /* Auto create device node in driver or not */
-
-//#define DEV_MAJOR 79
-#ifndef DEV_MAJOR
-#define DEV_MAJOR 0
-#endif
-
-int dev_major = DEV_MAJOR;
+int dev_major = 0;
module_param(dev_major, int, S_IRUGO);
+#define BUF_SIZE 1024
typedef struct chrdev_s
{
struct cdev cdev;
-#ifdef CONFIG_AUTODEV
- struct class *class;
- struct device *device;
-#endif
char *data; /* data buffer */
uint32_t size; /* data buffer size */
uint32_t bytes; /* data bytes in the buffer */
@@ -109,19 +90,29 @@
return rv;
}
-/* The ioctl() implementation */
-long chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5,0,0)
+#define access_ok_wrapper(type,arg,cmd) access_ok(type, arg, cmd)
+#else
+#define access_ok_wrapper(type,arg,cmd) access_ok(arg, cmd)
+#endif
+
+/* ioctl definitions, use 'c' as magic number */
+#define CHR_MAGIC 'c'
+#define CHR_MAXNR 2
+#define CMD_READ _IOR(CHR_MAGIC, 0, int)
+#define CMD_WRITE _IOW(CHR_MAGIC, 1, int)
+
+static long chrdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
- struct chrdev_s *dev = file->private_data;
- int rv, data;
- size_t bytes = sizeof(data);
+ static int value = 0xdeadbeef;
+ int rv = 0;
/*
* extract the type and number bitfields, and don't decode
* wrong cmds: return ENOTTY (inappropriate ioctl) before access_ok()
*/
- if (_IOC_TYPE(cmd) != CHRDEV_IOC_MAGIC) return -ENOTTY;
- if (_IOC_NR(cmd) > CHRDEV_IOC_MAXNR) return -ENOTTY;
+ if (_IOC_TYPE(cmd) != CHR_MAGIC) return -ENOTTY;
+ if (_IOC_NR(cmd) > CHR_MAXNR) return -ENOTTY;
/*
* the direction is a bitmask, and VERIFY_WRITE catches R/W transfers.
@@ -132,32 +123,26 @@
rv = !access_ok_wrapper(VERIFY_WRITE, (void __user *)arg, _IOC_SIZE(cmd));
else if (_IOC_DIR(cmd) & _IOC_WRITE)
rv = !access_ok_wrapper(VERIFY_READ, (void __user *)arg, _IOC_SIZE(cmd));
- if (rv) return -EFAULT;
- switch(cmd) {
- case CHRDEV_IOCRESET:
- dev->bytes = 0;
- memset(dev->data, 0, dev->size);
- rv = 0;
+ if (rv)
+ return -EFAULT;
+
+ switch (cmd) {
+ case CMD_READ:
+ if (copy_to_user((int __user *)arg, &value, sizeof(value)))
+ return -EFAULT;
break;
- /* Last 4 bytes in the buffer used to save ioctl() data*/
- case CHRDEV_IOCSET:
- rv = __get_user(data, (int __user *)arg);
- if( !rv )
- memcpy(&dev->data[dev->size-bytes], &data, bytes);
- break;
-
- case CHRDEV_IOCGET:
- memcpy(&data, &dev->data[dev->size-bytes], bytes);
- rv = __put_user(data, (int __user *)arg);
+ case CMD_WRITE:
+ if (copy_from_user(&value, (int __user *)arg, sizeof(value)))
+ return -EFAULT;
break;
default:
- return -ENOTTY;
+ return -EINVAL;
}
- return rv;
+ return 0;
}
static int chrdev_open (struct inode *inode, struct file *file)
@@ -179,12 +164,12 @@
}
static struct file_operations chrdev_fops = {
- .owner = THIS_MODULE,
- .open = chrdev_open, /* open() implementation */
- .read = chrdev_read, /* read() implementation */
- .write = chrdev_write, /* write() implementation */
- .release = chrdev_close, /* close() implementation */
- .unlocked_ioctl = chrdev_ioctl, /* ioctl() implementation */
+ .owner = THIS_MODULE,
+ .open = chrdev_open, /* open() implementation */
+ .read = chrdev_read, /* read() implementation */
+ .write = chrdev_write, /* write() implementation */
+ .unlocked_ioctl = chrdev_ioctl, /* ioctl() implementation */
+ .release = chrdev_close, /* close() implementation */
};
static int __init chrdev_init(void)
@@ -193,17 +178,17 @@
int rv;
/* malloc and initial device read/write buffer */
- dev.data = kmalloc(DEV_SIZE, GFP_KERNEL);
+ dev.data = kmalloc(BUF_SIZE, GFP_KERNEL);
if( !dev.data )
{
printk(KERN_ERR " %s driver kmalloc() failed\n", DEV_NAME);
return -ENOMEM;
}
- dev.size = DEV_SIZE;
+ dev.size = BUF_SIZE;
dev.bytes = 0;
memset(dev.data, 0, dev.size);
- /* dynamic alloc device node major number if not set */
+ /* allocate device number */
if(0 != dev_major)
{
devno = MKDEV(dev_major, 0);
@@ -221,9 +206,11 @@
return -ENODEV;
}
- /* setup and register cdev into kernel */
+ /* initialize cdev and setup fops */
cdev_init(&dev.cdev, &chrdev_fops);
dev.cdev.owner = THIS_MODULE;
+
+ /* register cdev to linux kernel */
rv = cdev_add(&dev.cdev, devno, 1);
if( rv )
{
@@ -232,41 +219,11 @@
goto failed1;
}
-#ifdef CONFIG_AUTODEV
- /* create device node in user space */
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 5, 0)
- dev.class = class_create(DEV_NAME);
-#else
- dev.class = class_create(THIS_MODULE, DEV_NAME);
-#endif
- if (IS_ERR(dev.class)) {
- rv = PTR_ERR(dev.class);
- goto failed2;
- }
-
- dev.device = device_create(dev.class, NULL, MKDEV(dev_major, 0), NULL, DEV_NAME);
- if( !dev.device )
- {
- rv = -ENODEV;
- printk(KERN_ERR "%s driver create device failed\n", DEV_NAME);
- goto failed3;
- }
-#endif
-
printk(KERN_INFO "%s driver on major[%d] installed.\n", DEV_NAME, dev_major);
return 0;
-#ifdef CONFIG_AUTODEV
-failed3:
- class_destroy(dev.class);
-
-failed2:
- cdev_del(&dev.cdev);
-#endif
-
failed1:
unregister_chrdev_region(devno, 1);
- kfree(dev.data);
printk(KERN_ERR "%s driver installed failed.\n", DEV_NAME);
return rv;
@@ -274,11 +231,6 @@
static void __exit chrdev_exit(void)
{
-#ifdef CONFIG_AUTODEV
- device_del(dev.device);
- class_destroy(dev.class);
-#endif
-
cdev_del(&dev.cdev);
unregister_chrdev_region(MKDEV(dev_major,0), 1);
--
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