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/chrdev2.c | 81 ++++++++++------------------------------
1 files changed, 21 insertions(+), 60 deletions(-)
diff --git a/bsp/drivers/x86_64/ldd2_chrdev.c b/bsp/drivers/x86/driver/chrdev2.c
similarity index 71%
rename from bsp/drivers/x86_64/ldd2_chrdev.c
rename to bsp/drivers/x86/driver/chrdev2.c
index 11492f5..12dd37f 100644
--- a/bsp/drivers/x86_64/ldd2_chrdev.c
+++ b/bsp/drivers/x86/driver/chrdev2.c
@@ -1,37 +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>
/* 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 */
@@ -115,11 +109,11 @@
}
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 */
+ .owner = THIS_MODULE,
+ .open = chrdev_open, /* open() implementation */
+ .read = chrdev_read, /* read() implementation */
+ .write = chrdev_write, /* write() implementation */
+ .release = chrdev_close, /* close() implementation */
};
static int __init chrdev_init(void)
@@ -128,17 +122,17 @@
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);
@@ -156,9 +150,11 @@
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 )
{
@@ -167,41 +163,11 @@
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;
@@ -209,11 +175,6 @@
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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