kernel_module: move character device example doc to README

kernel_module/README.adoc

@@ -20,8 +20,6 @@
 ... link:dep2.c[]
 . Pseudo filesystems
 .. link:anonymous_inode.c[]
-.. link:character_device.c[]
-.. link:character_device_create.c[]
 .. link:debugfs.c[]
 .. link:fops.c[]
 .. link:ioctl.c[]

kernel_module/character_device.c

@@ -1,24 +1,3 @@
-/*
-Allows us to create device files with given file operations with mknod c X.
-
-Usage:
-
-	/character_device.sh
-
-The major number determines which module owns the device file.
-
-minor is to differentiate between multiple instances of the device,
-e.g. two NVIDIA GPUs using the same kernel module.
-
-We ask the kernel to automatically allocate a major number for us to avoid
-conlicts with other devices.
-
-Then we need to check /proc/devices to find out the assigned number,
-and use that for the mknod.
-
-- https://unix.stackexchange.com/questions/37829/understanding-character-device-or-character-special-files/371758#371758
-*/
-
 #include <linux/fs.h> /* register_chrdev, unregister_chrdev */
 #include <linux/module.h>
 #include <linux/seq_file.h> /* seq_read, seq_lseek, single_release */

kernel_module/character_device_create.c

@@ -1,9 +1,3 @@
-/*
-Automatically create the device under /dev on insmod, and remove on rmmod.
-
-https://stackoverflow.com/questions/5970595/how-to-create-a-device-node-from-the-init-module-code-of-a-linux-kernel-module/45531867#45531867
-*/
-
 #include <linux/cdev.h>
 #include <linux/device.h>
 #include <linux/fs.h> /* register_chrdev, unregister_chrdev */