etisserant@391: #include <linux/module.h>
etisserant@391: #include <linux/kthread.h>
etisserant@391: #include <linux/fs.h>
etisserant@391: #include <linux/cdev.h>
etisserant@391: #include <asm/uaccess.h>
etisserant@391: 
etisserant@391: #include "TestMasterSlave.h"
etisserant@391: #include "console/console.h"
etisserant@391: 
etisserant@391: #define minor 0
etisserant@391: 
etisserant@391: MODULE_LICENSE("GPL");
etisserant@391: 
etisserant@391: static dev_t canftest_dev;
etisserant@391: static struct cdev *canftest_cdev;
etisserant@391: static struct task_struct *thread_start_p, *thread_stop_p;
etisserant@391: static DECLARE_MUTEX (canftest_mutex);
etisserant@391: static int canftest_stopped = 1;
etisserant@391: 
greg@467: int thread_start (void* data);
greg@467: int thread_stop (void* data);
greg@467: 
etisserant@391: // handler processing write() requests from user-space
etisserant@391: ssize_t canftest_write(struct file *filp, const char __user *buf, size_t count,
etisserant@391: 		       loff_t *f_pos)
etisserant@391: {
etisserant@391: 	int cmd;
etisserant@391: 
etisserant@391: 	// get integer from user-space
etisserant@391: 	if (get_user (cmd, buf))
etisserant@391: 		return -EFAULT;
etisserant@391: 
etisserant@391: 	// process integer as command
etisserant@391: 	switch (cmd) {
etisserant@391: 		case CMD_START:
greg@467: 			if (!canftest_stopped) break;
greg@467: 			thread_start_p = kthread_create (thread_start, NULL, "canftest_start");
greg@467: 
greg@467: 			if (PTR_ERR(thread_start_p) == -ENOMEM) {
greg@467: 				printk(KERN_WARNING "canftest: error creating start thread\n");
greg@467: 				return -ENOMEM;
greg@467: 			}
greg@467: 
etisserant@391: 			wake_up_process (thread_start_p);
etisserant@391: 			break;
greg@467: 
etisserant@391: 		case CMD_STOP:
etisserant@391: 			if (canftest_stopped) break;
greg@467: 			thread_stop_p = kthread_create (thread_stop, NULL, "canftest_stop");
greg@467: 
greg@467: 			if (PTR_ERR(thread_stop_p) == -ENOMEM) {
greg@467: 				printk(KERN_WARNING "canftest: error creating stop thread\n");
greg@467: 				return -ENOMEM;
greg@467: 			}
greg@467: 
etisserant@391: 			wake_up_process (thread_stop_p);
etisserant@391: 			break;
greg@467: 
etisserant@391: 		// ignore new line character
etisserant@391: 		case 10:
etisserant@391: 			break;
greg@467: 
etisserant@391: 		default:
etisserant@391: 			printk("canftest: bad command %d\n", cmd);
etisserant@391: 			break;
etisserant@391: 	}
etisserant@391: 	
etisserant@391: 	return count;
etisserant@391: }
etisserant@391: 
etisserant@391: // register write() handler
etisserant@391: static struct file_operations canftest_fops = {
etisserant@391: 	.owner =    THIS_MODULE,
etisserant@391: 	.write =    canftest_write,
etisserant@391: };
etisserant@391: 
etisserant@391: // start TestMasterSlave example
etisserant@391: int thread_start (void* data)
etisserant@391: {
etisserant@391: 	int ret=0;
etisserant@391: 	
etisserant@391: 	down_interruptible (&canftest_mutex);
etisserant@391: 	
etisserant@391: 	ret=TestMasterSlave_start();
etisserant@391: 
etisserant@391: 	// if started
etisserant@391: 	if (ret == 0) {
etisserant@391: 		canftest_stopped = 0;
etisserant@391: 
etisserant@391: 		// increment module usage count
etisserant@391: 		try_module_get(THIS_MODULE);
etisserant@391: 	}
etisserant@391: 	
etisserant@391: 	up (&canftest_mutex);
etisserant@391: 
etisserant@391: 	return ret;
etisserant@391: }
etisserant@391: 
etisserant@391: // finish TestMasterSlave example
etisserant@391: int thread_stop (void* data)
etisserant@391: {
etisserant@391: 	down_interruptible (&canftest_mutex);
etisserant@391: 
etisserant@391: 	TestMasterSlave_stop();
etisserant@391: 	canftest_stopped = 1;
etisserant@391: 
etisserant@391: 	// decrement usage count
etisserant@391: 	module_put(THIS_MODULE);
etisserant@391: 	
etisserant@391: 	up (&canftest_mutex);
etisserant@391: 
etisserant@391: 	return 0;
etisserant@391: }
etisserant@391: 
etisserant@391: int init_module(void)
etisserant@391: {
etisserant@391: 	int ret, major;
etisserant@391: 
etisserant@391: 	// get major device number dynamically
etisserant@391: 	ret = alloc_chrdev_region(&canftest_dev, minor, 1, DEVICE_NAME);
etisserant@391: 	major = MAJOR(canftest_dev);
etisserant@391: 	if (ret < 0) {
etisserant@391: 		printk(KERN_WARNING "canftest: can't get major %d\n", major);
etisserant@391: 		return ret;
etisserant@391: 	}
etisserant@391: 	
etisserant@391: 	canftest_cdev = cdev_alloc( );
etisserant@391: 	canftest_cdev->owner = THIS_MODULE;
etisserant@391: 	canftest_cdev->ops = &canftest_fops;
etisserant@391: 	
etisserant@391: 	// register new character device
etisserant@391: 	ret = cdev_add (canftest_cdev, canftest_dev, 1);
etisserant@391: 	if (ret) {
etisserant@391: 		printk(KERN_WARNING "canftest: error %d adding char device\n", ret);
etisserant@391: 		return ret;
etisserant@391: 	}
etisserant@391: 
etisserant@391: 	return 0;
etisserant@391: }
etisserant@391: 
etisserant@391: void cleanup_module(void)
etisserant@391: {
etisserant@391: 	// unregister major device number and character device
etisserant@391: 	unregister_chrdev_region(canftest_dev, 1);
etisserant@391: 	cdev_del(canftest_cdev);
etisserant@391: }