staging: comedi: comedi_parport: tidy up the register map

Rename the register map defines to better describe the hardware.

Add defines for the control register bits that enable the irq and
change the direction of the data register. This gets rid of the
"magic" numbers.

Remove PARPORT_SIZE, it's only used when requesting the i/o region
with comedi_request_region().
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/comedi_parport.c

@@ -82,11 +82,14 @@ pin, which can be used to wake up tasks.
 
 #include "comedi_fc.h"
 
-#define PARPORT_SIZE 3
-
-#define PARPORT_A 0
-#define PARPORT_B 1
-#define PARPORT_C 2
+/*
+ * Register map
+ */
+#define PARPORT_DATA_REG	0x00
+#define PARPORT_STATUS_REG	0x01
+#define PARPORT_CTRL_REG	0x02
+#define PARPORT_CTRL_IRQ_ENA	(1 << 4)
+#define PARPORT_CTRL_BIDIR_ENA	(1 << 5)
 
 struct parport_private {
 	unsigned int a_data;
@@ -103,10 +106,10 @@ static int parport_insn_a(struct comedi_device *dev, struct comedi_subdevice *s,
 		devpriv->a_data &= ~data[0];
 		devpriv->a_data |= (data[0] & data[1]);
 
-		outb(devpriv->a_data, dev->iobase + PARPORT_A);
+		outb(devpriv->a_data, dev->iobase + PARPORT_DATA_REG);
 	}
 
-	data[1] = inb(dev->iobase + PARPORT_A);
+	data[1] = inb(dev->iobase + PARPORT_DATA_REG);
 
 	return insn->n;
 }
@@ -119,12 +122,12 @@ static int parport_insn_config_a(struct comedi_device *dev,
 
 	if (data[0]) {
 		s->io_bits = 0xff;
-		devpriv->c_data &= ~(1 << 5);
+		devpriv->c_data &= ~PARPORT_CTRL_BIDIR_ENA;
 	} else {
 		s->io_bits = 0;
-		devpriv->c_data |= (1 << 5);
+		devpriv->c_data |= PARPORT_CTRL_BIDIR_ENA;
 	}
-	outb(devpriv->c_data, dev->iobase + PARPORT_C);
+	outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
 
 	return 1;
 }
@@ -137,7 +140,7 @@ static int parport_insn_b(struct comedi_device *dev, struct comedi_subdevice *s,
 		/* anyone??? */
 	}
 
-	data[1] = (inb(dev->iobase + PARPORT_B) >> 3);
+	data[1] = (inb(dev->iobase + PARPORT_STATUS_REG) >> 3);
 
 	return insn->n;
 }
@@ -152,7 +155,7 @@ static int parport_insn_c(struct comedi_device *dev, struct comedi_subdevice *s,
 		devpriv->c_data &= ~data[0];
 		devpriv->c_data |= (data[0] & data[1]);
 
-		outb(devpriv->c_data, dev->iobase + PARPORT_C);
+		outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
 	}
 
 	data[1] = devpriv->c_data & 0xf;
@@ -215,8 +218,8 @@ static int parport_intr_cmd(struct comedi_device *dev,
 {
 	struct parport_private *devpriv = dev->private;
 
-	devpriv->c_data |= 0x10;
-	outb(devpriv->c_data, dev->iobase + PARPORT_C);
+	devpriv->c_data |= PARPORT_CTRL_IRQ_ENA;
+	outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
 
 	devpriv->enable_irq = 1;
 
@@ -228,8 +231,8 @@ static int parport_intr_cancel(struct comedi_device *dev,
 {
 	struct parport_private *devpriv = dev->private;
 
-	devpriv->c_data &= ~0x10;
-	outb(devpriv->c_data, dev->iobase + PARPORT_C);
+	devpriv->c_data &= ~PARPORT_CTRL_IRQ_ENA;
+	outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
 
 	devpriv->enable_irq = 0;
 
@@ -260,7 +263,7 @@ static int parport_attach(struct comedi_device *dev,
 	unsigned int irq;
 	int ret;
 
-	ret = comedi_request_region(dev, it->options[0], PARPORT_SIZE);
+	ret = comedi_request_region(dev, it->options[0], 0x03);
 	if (ret)
 		return ret;
 
@@ -325,9 +328,9 @@ static int parport_attach(struct comedi_device *dev,
 	}
 
 	devpriv->a_data = 0;
-	outb(devpriv->a_data, dev->iobase + PARPORT_A);
+	outb(devpriv->a_data, dev->iobase + PARPORT_DATA_REG);
 	devpriv->c_data = 0;
-	outb(devpriv->c_data, dev->iobase + PARPORT_C);
+	outb(devpriv->c_data, dev->iobase + PARPORT_CTRL_REG);
 
 	return 0;
 }