.h file:
@interface MyTextViewViewController : UIViewController <UITextViewDelegate>
{
	UITextView *m_textView;
	UIBarButtonItem *doneBarButtonItem;
}

@property(nonatomic,retain) IBOutlet UITextView *m_textView;
@property(nonatomic,retain) IBOutlet UIBarButtonItem *doneBarButtonItem;

- (IBAction)saveAction:(id)sender;

----------------------------
.m file:
...
- (void)viewWillAppear:(BOOL)animated 
{
    // listen for keyboard hide/show notifications so we can properly adjust the table's height
    [super viewWillAppear:animated];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}

- (void)viewDidDisappear:(BOOL)animated 
{
    [super viewDidDisappear:animated];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}

- (void)keyboardWillShow:(NSNotification *)aNotification 
{
   // the keyboard is showing so resize the table's height
   CGRect keyboardRect = [[[aNotification userInfo] objectForKey:UIKeyboardBoundsUserInfoKey] CGRectValue];
    NSTimeInterval animationDuration = [[[aNotification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    CGRect frame = self.view.frame;
    frame.size.height -= keyboardRect.size.height;
    [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
    [UIView setAnimationDuration:animationDuration];
    self.view.frame = frame;
    [UIView commitAnimations];
}

- (void)keyboardWillHide:(NSNotification *)aNotification
{
    // the keyboard is hiding reset the table's height
    CGRect keyboardRect = [[[aNotification userInfo] objectForKey:UIKeyboardBoundsUserInfoKey] CGRectValue];
    NSTimeInterval animationDuration = [[[aNotification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    CGRect frame = self.view.frame;
    frame.size.height += keyboardRect.size.height;
    [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
    [UIView setAnimationDuration:animationDuration];
    self.view.frame = frame;
    [UIView commitAnimations];
}


#pragma mark -
#pragma mark UITextViewDelegate
- (void)textViewDidBeginEditing:(UITextView *)textView
{
	doneBarButtonItem.enabled = YES;
}

- (IBAction)saveAction:(id)sender
{
	doneBarButtonItem.enabled = NO;
	[self.m_textView resignFirstResponder];
}

Textview input is behind the keyboard

iPhone