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Commit 8fc9f652 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcl818: introduce pcl818_ai_get_sample() 



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: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 66581ca5

drivers/staging/comedi/drivers/pcl818.c

+21 −9
Original line number Diff line number Diff line
@@ -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 */