staging: comedi: pcl812: introduce pcl812_ai_get_sample()

Introduce a helper function to read the 12/16-bit analog input data
sample.

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>

diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c
index 4ecbb297dcb744ed102447d37d322dadb3818835..d7b125d4b16bd88b92fb11c0a2a11d7914637491 100644 (file)
--- a/drivers/staging/comedi/drivers/pcl812.c
+++ b/drivers/staging/comedi/drivers/pcl812.c
@@ -551,6 +551,17 @@ static void setup_range_channel(struct comedi_device *dev,
 static int pcl812_ai_cancel(struct comedi_device *dev,
                            struct comedi_subdevice *s);
 
+static unsigned int pcl812_ai_get_sample(struct comedi_device *dev,
+                                        struct comedi_subdevice *s)
+{
+       unsigned int val;
+
+       val = inb(dev->iobase + PCL812_AD_HI) << 8;
+       val |= inb(dev->iobase + PCL812_AD_LO);
+
+       return val & s->maxdata;
+}
+
 static int pcl812_ai_eoc(struct comedi_device *dev,
                         struct comedi_subdevice *s,
                         struct comedi_insn *insn,
@@ -578,7 +589,6 @@ static int pcl812_ai_insn_read(struct comedi_device *dev,
        struct pcl812_private *devpriv = dev->private;
        int ret = 0;
        int n;
-       int hi;
 
        /* select software trigger */
        outb(devpriv->mode_reg_int | 1, dev->iobase + PCL812_MODE);
@@ -593,8 +603,7 @@ static int pcl812_ai_insn_read(struct comedi_device *dev,
                if (ret)
                        break;
 
-               hi = inb(dev->iobase + PCL812_AD_HI);
-               data[n] = ((hi & 0xf) << 8) | inb(dev->iobase + PCL812_AD_LO);
+               data[n] = pcl812_ai_get_sample(dev, s);
        }
        outb(devpriv->mode_reg_int | 0, dev->iobase + PCL812_MODE);
 
@@ -621,9 +630,7 @@ static int acl8216_ai_insn_read(struct comedi_device *dev,
                if (ret)
                        break;
 
-               data[n] =
-                   (inb(dev->iobase +
-                        PCL812_AD_HI) << 8) | inb(dev->iobase + PCL812_AD_LO);
+               data[n] = pcl812_ai_get_sample(dev, s);
        }
        outb(0, dev->iobase + PCL812_MODE);
 
@@ -912,7 +919,7 @@ static int pcl812_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 static irqreturn_t interrupt_pcl812_ai_int(int irq, void *d)
 {
        char err = 1;
-       unsigned int mask, timeout;
+       unsigned int timeout;
        struct comedi_device *dev = d;
        struct pcl812_private *devpriv = dev->private;
        struct comedi_subdevice *s = dev->read_subdev;
@@ -922,7 +929,6 @@ static irqreturn_t interrupt_pcl812_ai_int(int irq, void *d)
 
        timeout = 50;           /* wait max 50us, it must finish under 33us */
        if (devpriv->ai_is16b) {
-               mask = 0xffff;
                while (timeout--) {
                        if (!(inb(dev->iobase + ACL8216_STATUS) & ACL8216_DRDY)) {
                                err = 0;
@@ -931,7 +937,6 @@ static irqreturn_t interrupt_pcl812_ai_int(int irq, void *d)
                        udelay(1);
                }
        } else {
-               mask = 0x0fff;
                while (timeout--) {
                        if (!(inb(dev->iobase + PCL812_AD_HI) & PCL812_DRDY)) {
                                err = 0;
@@ -949,9 +954,7 @@ static irqreturn_t interrupt_pcl812_ai_int(int irq, void *d)
                return IRQ_HANDLED;
        }
 
-       comedi_buf_put(s->async,
-                      ((inb(dev->iobase + PCL812_AD_HI) << 8) |
-                       inb(dev->iobase + PCL812_AD_LO)) & mask);
+       comedi_buf_put(s->async, pcl812_ai_get_sample(dev, s));
 
        /* Set up next channel. Added by abbotti 2010-01-20, but untested. */
        next_chan = s->async->cur_chan + 1;