staging: comedi: pcl816: add support for digital subdevices

The PCL-816 boards have 16 digital inputs and 16 digtial outputs. Add the
subdevice support for these channels.

Allocate additional subdevice space to the analog outputs. This code is
not currently in the driver so mark the subdevice as COMEDI_SUBD_UNUSED.
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/pcl816.c

@@ -44,6 +44,8 @@ Configuration Options:
 #include "comedi_fc.h"
 #include "8253.h"
 
+#define PCL816_DO_DI_LSB_REG			0x00
+#define PCL816_DO_DI_MSB_REG			0x01
 #define PCL816_TIMER_BASE			0x04
 
 /* R: A/D high byte W: A/D range control */
@@ -556,9 +558,6 @@ static void pcl816_reset(struct comedi_device *dev)
 
 /* outb (0, dev->iobase + PCL818_DA_LO);         DAC=0V */
 /* outb (0, dev->iobase + PCL818_DA_HI); */
-/* udelay (1); */
-/* outb (0, dev->iobase + PCL818_DO_HI);        DO=$0000 */
-/* outb (0, dev->iobase + PCL818_DO_LO); */
 /* udelay (1); */
 	outb(0, dev->iobase + PCL816_CONTROL);
 	outb(0, dev->iobase + PCL816_MUX);
@@ -570,6 +569,10 @@ static void pcl816_reset(struct comedi_device *dev)
 	i8254_set_mode(timer_base, 0, 0, I8254_MODE0 | I8254_BINARY);
 
 	outb(0, dev->iobase + PCL816_RANGE);
+
+	/* set all digital outputs low */
+	outb(0, dev->iobase + PCL816_DO_DI_LSB_REG);
+	outb(0, dev->iobase + PCL816_DO_DI_MSB_REG);
 }
 
 static int
@@ -650,6 +653,32 @@ setup_channel_list(struct comedi_device *dev,
 	     dev->iobase + PCL816_MUX);
 }
 
+static int pcl816_di_insn_bits(struct comedi_device *dev,
+			       struct comedi_subdevice *s,
+			       struct comedi_insn *insn,
+			       unsigned int *data)
+{
+	data[1] = inb(dev->iobase + PCL816_DO_DI_LSB_REG) |
+		  (inb(dev->iobase + PCL816_DO_DI_MSB_REG) << 8);
+
+	return insn->n;
+}
+
+static int pcl816_do_insn_bits(struct comedi_device *dev,
+			       struct comedi_subdevice *s,
+			       struct comedi_insn *insn,
+			       unsigned int *data)
+{
+	if (comedi_dio_update_state(s, data)) {
+		outb(s->state & 0xff, dev->iobase + PCL816_DO_DI_LSB_REG);
+		outb((s->state >> 8), dev->iobase + PCL816_DO_DI_MSB_REG);
+	}
+
+	data[1] = s->state;
+
+	return insn->n;
+}
+
 static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 {
 	const struct pcl816_board *board = comedi_board(dev);
@@ -700,7 +729,7 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		}
 	}
 
-	ret = comedi_alloc_subdevices(dev, 1);
+	ret = comedi_alloc_subdevices(dev, 4);
 	if (ret)
 		return ret;
 
@@ -721,28 +750,34 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		s->cancel	= pcl816_ai_cancel;
 	}
 
+	/* Analog OUtput subdevice */
+	s = &dev->subdevices[2];
+	s->type		= COMEDI_SUBD_UNUSED;
 #if 0
 	subdevs[1] = COMEDI_SUBD_AO;
 	s->subdev_flags = SDF_WRITABLE | SDF_GROUND;
 	s->n_chan = 1;
 	s->maxdata = board->ao_maxdata;
 	s->range_table = &range_pcl816;
-	break;
+#endif
 
-	subdevs[2] = COMEDI_SUBD_DI;
+	/* Digital Input subdevice */
+	s = &dev->subdevices[2];
+	s->type		= COMEDI_SUBD_DI;
 	s->subdev_flags	= SDF_READABLE;
 	s->n_chan	= 16;
 	s->maxdata	= 1;
 	s->range_table	= &range_digital;
-	break;
+	s->insn_bits	= pcl816_di_insn_bits;
 
-	subdevs[3] = COMEDI_SUBD_DO;
+	/* Digital Output subdevice */
+	s = &dev->subdevices[3];
+	s->type		= COMEDI_SUBD_DO;
 	s->subdev_flags	= SDF_WRITABLE;
 	s->n_chan	= 16;
 	s->maxdata	= 1;
 	s->range_table	= &range_digital;
-	break;
-#endif
+	s->insn_bits	= pcl816_do_insn_bits;
 
 	pcl816_reset(dev);