Lab03 device drivers

tools/labs/skels/device_drivers/extra/char-driver-lin/Kbuild

@@ -0,0 +1,3 @@
+ccflags-y = -Wno-unused-function -Wno-unused-label -Wno-unused-variable
+
+obj-m        = modul.o

tools/labs/skels/device_drivers/extra/char-driver-lin/makenode

@@ -0,0 +1,9 @@
+#!/bin/sh
+device="my_device"
+major=42
+
+
+rm -f /dev/${device}
+mknod /dev/${device} c $major 0
+
+

tools/labs/skels/device_drivers/extra/char-driver-lin/modul.c

@@ -0,0 +1,124 @@
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <asm/ioctl.h>
+
+#define MY_MAJOR 42
+#define MY_MAX_MINORS 2
+/* #define IOCTL_IN _IOC(_IOC_WRITE, 'k', 1, sizeof(my_ioctl_data)) */
+#define MY_IOCTL_IN _IOC(_IOC_WRITE, 'k', 1, 0)
+
+struct my_device_data {
+    struct cdev cdev;
+    /* my data starts here */
+}devs[MY_MAX_MINORS];
+
+MODULE_DESCRIPTION("My kernel module");
+MODULE_AUTHOR("Me");
+MODULE_LICENSE("GPL");
+
+static int my_open(struct inode *inode, struct file *file) {
+    struct my_device_data *my_data =
+            container_of(inode->i_cdev, struct my_device_data, cdev);
+
+	printk( KERN_DEBUG "[my_open]\n" );		
+    /* validate access to device */
+    file->private_data = my_data;
+    /* initialize device */
+
+    return 0;
+}
+
+static int my_close(struct inode *inode, struct file *file) {
+	printk( KERN_DEBUG "[my_close]\n" );
+    /* deinitialize device */
+    return 0;
+}
+
+static int my_read(struct file *file, char __user *user_buffer, size_t size, loff_t *offset) {
+    struct my_device_data *my_data =
+             (struct my_device_data*) file->private_data;
+	int sizeRead = 0;		 
+
+	printk( KERN_DEBUG "[my_read]\n" );
+    /* read data from device in my_data->buffer */
+	/* if(copy_to_user(user_buffer, my_data->buffer, my_data->size))
+        return -EFAULT; */
+
+    return sizeRead;
+}
+
+static int my_write(struct file *file, const char __user *user_buffer, size_t size, loff_t *offset) {
+    struct my_device_data *my_data =
+             (struct my_device_data*) file->private_data;
+	int sizeWritten = 0;		 
+
+	printk( KERN_DEBUG "[my_write]\n" );
+    /* copy_from_user */
+	/* write data to device from my_data->buffer */
+	sizeWritten	= size;						//only if sizeWritten == size !
+
+    return sizeWritten;
+}
+
+static long my_ioctl (struct file *file, unsigned int cmd, unsigned long arg) {
+    struct my_device_data *my_data =
+         (struct my_device_data*) file->private_data;
+	/* my_ioctl_data mid; */
+
+	printk( KERN_DEBUG "[my_ioctl]\n" );
+    switch(cmd) {
+    case MY_IOCTL_IN:
+        /* if( copy_from_user(&mid, (my_ioctl_data *) arg, sizeof(my_ioctl_data)) )
+            return -EFAULT;  */	
+
+        /* process data and execute command */
+        break;
+    default:
+        return -ENOTTY;
+    }
+    return 0;
+}
+
+
+struct file_operations my_fops = {
+    .owner = THIS_MODULE,
+    .open = my_open,
+    .read = my_read,
+    .write = my_write,
+    .release = my_close,
+    .unlocked_ioctl = my_ioctl
+};
+
+int init_module(void) {
+    int i, err;
+
+	printk( KERN_DEBUG "[init_module]\n" );
+    err = register_chrdev_region(MKDEV(MY_MAJOR, 0), MY_MAX_MINORS,"my_device_driver");
+    if (err != 0) {
+        /* report error */
+        return err;
+    }
+
+    for(i = 0; i < MY_MAX_MINORS; i++) {
+        /* initialize devs[i] fields */
+        cdev_init(&devs[i].cdev, &my_fops);
+        cdev_add(&devs[i].cdev, MKDEV(MY_MAJOR, i), 1);
+    }
+
+    return 0;
+}
+
+void cleanup_module(void) {
+    int i;
+
+	printk( KERN_DEBUG "[cleanup_module]\n" );
+    for(i = 0; i < MY_MAX_MINORS; i++) {
+        /* release devs[i] fields */
+        cdev_del(&devs[i].cdev);
+    }
+    unregister_chrdev_region(MKDEV(MY_MAJOR, 0), MY_MAX_MINORS);
+}
+

tools/labs/skels/device_drivers/include/so2_cdev.h

@@ -0,0 +1,14 @@
+#ifndef __PSOCDEV_H__
+#define __PSOCDEV_H__		1
+
+#include <asm/ioctl.h>
+
+#define BUFFER_SIZE		256
+
+#define MY_IOCTL_PRINT		_IOC(_IOC_NONE,  'k', 1, 0)
+#define MY_IOCTL_SET_BUFFER	_IOC(_IOC_WRITE, 'k', 2, BUFFER_SIZE)
+#define MY_IOCTL_GET_BUFFER	_IOC(_IOC_READ,  'k', 3, BUFFER_SIZE)
+#define MY_IOCTL_DOWN		_IOC(_IOC_NONE,  'k', 4, 0)
+#define MY_IOCTL_UP		_IOC(_IOC_NONE,  'k', 5, 0)
+
+#endif

tools/labs/skels/device_drivers/kernel/Kbuild

@@ -0,0 +1,3 @@
+ccflags-y = -Wno-unused-function -Wno-unused-label -Wno-unused-variable
+
+obj-m = so2_cdev.o