staging: comedi: das800: clarify 8254 timer programming
authorH Hartley Sweeten <hsweeten@visionengravers.com>
Tue, 29 Apr 2014 19:59:55 +0000 (12:59 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 4 May 2014 00:06:35 +0000 (20:06 -0400)
Refactor the 8254 timer programming to use the i8254_set_mode()
and i8254_write() helpers instead of i8254_load(). This allows
us to use the I8254_MODE* defines to clarify the code.

The das800_set_frequency() function will not fail. For aesthetics
change the return to a void and remove the error handling.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/comedi/drivers/das800.c

index e2dc43dbdc5ea605c7ce130a0e2caa0c1d2cb031..615ae3f1c6cc8dfb4724f9196442fea3b44786cf 100644 (file)
@@ -275,19 +275,15 @@ static void das800_disable(struct comedi_device *dev)
        spin_unlock_irqrestore(&dev->spinlock, irq_flags);
 }
 
-static int das800_set_frequency(struct comedi_device *dev)
+static void das800_set_frequency(struct comedi_device *dev)
 {
        struct das800_private *devpriv = dev->private;
-       int err = 0;
-
-       if (i8254_load(dev->iobase + DAS800_8254, 0, 1, devpriv->divisor1, 2))
-               err++;
-       if (i8254_load(dev->iobase + DAS800_8254, 0, 2, devpriv->divisor2, 2))
-               err++;
-       if (err)
-               return -1;
+       unsigned long timer_base = dev->iobase + DAS800_8254;
 
-       return 0;
+       i8254_set_mode(timer_base, 0, 1, I8254_MODE2 | I8254_BINARY);
+       i8254_set_mode(timer_base, 0, 2, I8254_MODE2 | I8254_BINARY);
+       i8254_write(timer_base, 0, 1, devpriv->divisor1);
+       i8254_write(timer_base, 0, 2, devpriv->divisor2);
 }
 
 static int das800_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
@@ -448,10 +444,7 @@ static int das800_ai_do_cmd(struct comedi_device *dev,
        if (async->cmd.convert_src == TRIG_TIMER) {
                conv_bits |= CASC | ITE;
                /* set conversion frequency */
-               if (das800_set_frequency(dev) < 0) {
-                       comedi_error(dev, "Error setting up counters");
-                       return -1;
-               }
+               das800_set_frequency(dev);
        }
 
        spin_lock_irqsave(&dev->spinlock, irq_flags);