补充杂项设备示例程序.

Signed-off-by: ithink.chan <chenyang@autoai.com>

Software/OperatingSystem/Linux/Modules/KernelDriver/Demo/Misc/Makefile

@@ -0,0 +1,14 @@
+obj-m:= \
+    demomisc.o
+
+demomisc-objs:= \
+	demo_misc.o
+
+EXTRA_CFLAGS += \
+    -I$(PWD)
+
+all:
+	$(MAKE) -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+
+clean:
+	$(MAKE) -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

Software/OperatingSystem/Linux/Modules/KernelDriver/Demo/Misc/demo_misc.c

@@ -0,0 +1,72 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+
+static int demo_open(struct inode *inode, struct file* filp)
+{
+    return 0;
+}
+
+static int demo_release(struct inode *inode, struct file* filp)
+{
+    return 0;
+}
+
+static loff_t demo_llseek(struct file *filp, loff_t offset, int origin)
+{
+    return filp->f_pos;
+}
+
+static ssize_t demo_read(struct file *filp, char __user *buffer, size_t count, loff_t *offset)
+{
+    const char __user *p = buffer;
+    return p-buffer;
+}
+
+static ssize_t demo_write(struct file *filp, const char __user *buffer, size_t count, loff_t *offset)
+{
+    const char __user *p = buffer;
+    return p-buffer;
+}
+
+static long demo_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+    return 0;
+}
+
+static int demo_mmap(struct file* filp, struct vm_area_struct* vma)
+{
+    return 0;
+}
+
+static struct file_operations demo_fops = {
+    .owner          = THIS_MODULE,
+    .open           = demo_open,
+    .release        = demo_release,
+    .llseek         = demo_llseek,
+    .read           = demo_read,
+    .write          = demo_write,
+    .unlocked_ioctl = demo_ioctl,
+    .mmap           = demo_mmap
+};
+
+static struct miscdevice demo_dev = {
+	.minor  = MISC_DYNAMIC_MINOR,   // Dynamically allocate minor.
+	.name   = "demo_misc",
+	.fops   = &demo_fops,
+};
+
+static int __init demo_init(void)
+{
+    misc_register(&demo_dev);
+    return 0;
+}
+
+static void __exit demo_exit(void)
+{
+    misc_deregister(&demo_dev);
+}
+
+module_init(demo_init);
+module_exit(demo_exit);