[PATCH 42/48] staging: comedi: pcl816: use comedi_timeout()

Ian Abbott abbotti at mev.co.uk
Fri Feb 7 15:35:52 UTC 2014


On 2014-02-06 23:49, H Hartley Sweeten wrote:
> Use comedi_timeout() to wait for the analog input end-of-conversion.
>
> The interrupt routine also uses the timeout check to make sure data
> is actually available. Using NULL here for the 'insn' is safe since
> nothing uses it.

No good in interrupt routine, I think.

>
> Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
> Cc: Ian Abbott <abbotti at mev.co.uk>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> ---
>   drivers/staging/comedi/drivers/pcl816.c | 57 +++++++++++++++------------------
>   1 file changed, 25 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/staging/comedi/drivers/pcl816.c b/drivers/staging/comedi/drivers/pcl816.c
> index e9d4704..b3a2af3 100644
> --- a/drivers/staging/comedi/drivers/pcl816.c
> +++ b/drivers/staging/comedi/drivers/pcl816.c
> @@ -160,16 +160,25 @@ static int pcl816_ai_cmdtest(struct comedi_device *dev,
>   			     struct comedi_cmd *cmd);
>   static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s);
>
> -/*
> -==============================================================================
> -   ANALOG INPUT MODE0, 816 cards, slow version
> -*/
> +static int pcl816_ai_eoc(struct comedi_device *dev,
> +			 struct comedi_subdevice *s,
> +			 struct comedi_insn *insn,
> +			 unsigned long context)
> +{
> +	unsigned int status;
> +
> +	status = inb(dev->iobase + PCL816_STATUS);
> +	if ((status & PCL816_STATUS_DRDY_MASK) == 0)
> +		return 0;
> +	return -EBUSY;
> +}
> +
>   static int pcl816_ai_insn_read(struct comedi_device *dev,
>   			       struct comedi_subdevice *s,
>   			       struct comedi_insn *insn, unsigned int *data)
>   {
> +	int ret;
>   	int n;
> -	int timeout;
>
>   	/*  software trigger, DMA and INT off */
>   	outb(0, dev->iobase + PCL816_CONTROL);
> @@ -185,30 +194,20 @@ static int pcl816_ai_insn_read(struct comedi_device *dev,
>
>   		outb(0, dev->iobase + PCL816_AD_LO);	/* start conversion */
>
> -		timeout = 100;
> -		while (timeout--) {
> -			if (!(inb(dev->iobase + PCL816_STATUS) &
> -			      PCL816_STATUS_DRDY_MASK)) {
> -				/*  return read value */
> -				data[n] =
> -				    ((inb(dev->iobase +
> -					  PCL816_AD_HI) << 8) |
> -				     (inb(dev->iobase + PCL816_AD_LO)));
> -				/* clear INT (conversion end) flag */
> -				outb(0, dev->iobase + PCL816_CLRINT);
> -				break;
> -			}
> -			udelay(1);
> -		}
> -		/*  Return timeout error */
> -		if (!timeout) {
> +		ret = comedi_timeout(dev, s, insn, pcl816_ai_eoc, 0);
> +		if (ret) {
>   			comedi_error(dev, "A/D insn timeout\n");
>   			data[0] = 0;
>   			/* clear INT (conversion end) flag */
>   			outb(0, dev->iobase + PCL816_CLRINT);
> -			return -EIO;
> +			return ret;
>   		}
>
> +		/*  return read value */
> +		data[n] = ((inb(dev->iobase + PCL816_AD_HI) << 8) |
> +			  (inb(dev->iobase + PCL816_AD_LO)));
> +		/* clear INT (conversion end) flag */
> +		outb(0, dev->iobase + PCL816_CLRINT);
>   	}
>   	return n;
>   }
> @@ -224,22 +223,16 @@ static irqreturn_t interrupt_pcl816_ai_mode13_int(int irq, void *d)
>   	struct pcl816_private *devpriv = dev->private;
>   	struct comedi_subdevice *s = dev->read_subdev;
>   	unsigned char low, hi;
> -	int timeout = 50;	/* wait max 50us */
> +	int ret;
>
> -	while (timeout--) {
> -		if (!(inb(dev->iobase + PCL816_STATUS) &
> -		      PCL816_STATUS_DRDY_MASK))
> -			break;
> -		udelay(1);
> -	}
> -	if (!timeout) {		/*  timeout, bail error */
> +	ret = comedi_timeout(dev, s, NULL, pcl816_ai_eoc, 0);
> +	if (ret) {
>   		outb(0, dev->iobase + PCL816_CLRINT);	/* clear INT request */
>   		comedi_error(dev, "A/D mode1/3 IRQ without DRDY!");
>   		pcl816_ai_cancel(dev, s);
>   		s->async->events |= COMEDI_CB_EOA | COMEDI_CB_ERROR;
>   		comedi_event(dev, s);
>   		return IRQ_HANDLED;
> -
>   	}
>
>   	/*  get the sample */
>


-- 
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbotti at mev.co.uk>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-


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