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Commit 421f1b68 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcl818: use common function to setup dma 



THe pcl818_ai_setup_dma() and pcl818_ai_setup_next_dma() functions are similar
other than the buffer switch and the inclusion of the "unread_samples" in
pcl818_ai_setup_next_dma() when calculating the dma size.

Merge these two functions by initializing the 'dma->cur_dma' in the callers
and passing '0' for the "unread_samples" when first starting the DMA.

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 296e3f18

drivers/staging/comedi/drivers/pcl818.c

+13 −35
Original line number Diff line number Diff line
@@ -332,49 +332,22 @@ static void pcl818_start_pacer(struct comedi_device *dev, bool load_counters) 
}



static void pcl818_ai_setup_dma(struct comedi_device *dev,

				struct comedi_subdevice *s)

{

	struct pcl818_private *devpriv = dev->private;

	struct comedi_isadma *dma = devpriv->dma;

	struct comedi_isadma_desc *desc = &dma->desc[0];

	unsigned int nsamples;



	comedi_isadma_disable(dma->chan);



	dma->cur_dma = 0;



	/*

	 * Determine dma size based on the buffer maxsize and the number of

	 * samples remaining in the command.

	 */

	nsamples = comedi_bytes_to_samples(s, desc->maxsize);

	nsamples = comedi_nsamples_left(s, nsamples);

	desc->size = comedi_samples_to_bytes(s, nsamples);

	comedi_isadma_program(desc);

}



static void pcl818_ai_setup_next_dma(struct comedi_device *dev,

				struct comedi_subdevice *s,

				unsigned int unread_samples)

{

	struct pcl818_private *devpriv = dev->private;

	struct comedi_isadma *dma = devpriv->dma;

	struct comedi_isadma_desc *desc;

	unsigned int max_samples;

	struct comedi_isadma_desc *desc = &dma->desc[dma->cur_dma];

	unsigned int max_samples = comedi_bytes_to_samples(s, desc->maxsize);

	unsigned int nsamples;



	comedi_isadma_disable(dma->chan);



	dma->cur_dma = 1 - dma->cur_dma;

	desc = &dma->desc[dma->cur_dma];



	/*

	 * Determine dma size based on the buffer maxsize plus the number of

	 * unread samples and the number of samples remaining in the command.

	 */

	max_samples = comedi_bytes_to_samples(s, desc->maxsize);

	nsamples = max_samples + unread_samples;

	nsamples = comedi_nsamples_left(s, nsamples);

	nsamples = comedi_nsamples_left(s, max_samples + unread_samples);

	if (nsamples > unread_samples) {

		nsamples -= unread_samples;

		desc->size = comedi_samples_to_bytes(s, nsamples);
@@ -554,7 +527,9 @@ static void pcl818_handle_dma(struct comedi_device *dev, 
	unsigned int val;

	int i;



	pcl818_ai_setup_next_dma(dev, s, nsamples);

	/* restart dma with the next buffer */

	dma->cur_dma = 1 - dma->cur_dma;

	pcl818_ai_setup_dma(dev, s, nsamples);



	for (i = 0; i < nsamples; i++) {

		val = ptr[i];
@@ -790,6 +765,7 @@ static int pcl818_ai_cmd(struct comedi_device *dev, 
			 struct comedi_subdevice *s)

{

	struct pcl818_private *devpriv = dev->private;

	struct comedi_isadma *dma = devpriv->dma;

	struct comedi_cmd *cmd = &s->async->cmd;

	unsigned int ctrl = 0;

	unsigned int seglen;
@@ -815,8 +791,10 @@ static int pcl818_ai_cmd(struct comedi_device *dev, 


	outb(PCL818_CNTENABLE_PACER_ENA, dev->iobase + PCL818_CNTENABLE_REG);



	if (devpriv->dma) {

		pcl818_ai_setup_dma(dev, s);

	if (dma) {

		/* setup and enable dma for the first buffer */

		dma->cur_dma = 0;

		pcl818_ai_setup_dma(dev, s, 0);



		ctrl |= PCL818_CTRL_INTE | PCL818_CTRL_IRQ(dev->irq) |

			PCL818_CTRL_DMAE;