Introduce a helper function to read the 12-bit analog input data
sample and optionally return the channel that the sample was for.
The channel is only used in the interrupt routine to check for
dropped samples.
Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/staging/comedi/drivers/pcl818.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl818.c
b/drivers/staging/comedi/drivers/pcl818.c
index 2b8e7e0..d5709ed 100644
--- a/drivers/staging/comedi/drivers/pcl818.c
+++ b/drivers/staging/comedi/drivers/pcl818.c
@@ -372,6 +372,21 @@ static int pcl818_ai_cancel(struct comedi_device *dev,
static void start_pacer(struct comedi_device *dev, int mode,
unsigned int divisor1, unsigned int divisor2);
+static unsigned int pcl818_ai_get_sample(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ unsigned int *chan)
+{
+ unsigned int val;
+
+ val = inb(dev->iobase + PCL818_AD_HI) << 8;
+ val |= inb(dev->iobase + PCL818_AD_LO);
+
+ if (chan)
+ *chan = val & 0xf;
+
+ return (val >> 4) & s->maxdata;
+}
+
static int pcl818_ai_eoc(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
@@ -416,8 +431,7 @@ static int pcl818_ai_insn_read(struct comedi_device *dev,
return ret;
}
- data[n] = ((inb(dev->iobase + PCL818_AD_HI) << 4) |
- (inb(dev->iobase + PCL818_AD_LO) >> 4));
+ data[n] = pcl818_ai_get_sample(dev, s, NULL);
}
return n;
@@ -502,7 +516,7 @@ static irqreturn_t interrupt_pcl818_ai_mode13_int(int irq,
void *d)
struct comedi_device *dev = d;
struct pcl818_private *devpriv = dev->private;
struct comedi_subdevice *s = dev->read_subdev;
- unsigned char low;
+ unsigned int chan;
int timeout = 50; /* wait max 50us */
while (timeout--) {
@@ -518,14 +532,13 @@ static irqreturn_t interrupt_pcl818_ai_mode13_int(int
irq, void *d)
return IRQ_HANDLED;
conv_finish:
- low = inb(dev->iobase + PCL818_AD_LO);
- comedi_buf_put(s->async, ((inb(dev->iobase + PCL818_AD_HI) << 4) | (low
>> 4))); /* get one sample */
+ comedi_buf_put(s->async, pcl818_ai_get_sample(dev, s, &chan));
outb(0, dev->iobase + PCL818_CLRINT); /* clear INT request */
- if ((low & 0xf) != devpriv->act_chanlist[devpriv->act_chanlist_pos]) {
/* dropout! */
+ if (chan != devpriv->act_chanlist[devpriv->act_chanlist_pos]) {
dev_dbg(dev->class_dev,
"A/D mode1/3 IRQ - channel dropout %x!=%x !\n",
- (low & 0xf),
+ chan,
devpriv->act_chanlist[devpriv->act_chanlist_pos]);
pcl818_ai_cancel(dev, s);
s->async->events |= COMEDI_CB_EOA | COMEDI_CB_ERROR;
@@ -1166,8 +1179,7 @@ static int pcl818_ai_cancel(struct comedi_device *dev,
udelay(1);
start_pacer(dev, -1, 0, 0);
outb(0, dev->iobase + PCL818_AD_LO);
- inb(dev->iobase + PCL818_AD_LO);
- inb(dev->iobase + PCL818_AD_HI);
+ pcl818_ai_get_sample(dev, s, NULL);
outb(0, dev->iobase + PCL818_CLRINT); /* clear INT
request */
outb(0, dev->iobase + PCL818_CONTROL); /* Stop A/D */
if (devpriv->usefifo) { /* FIFO shutdown */
--
1.8.5.2
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