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Commit 93e60452 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcl816: use common function to setup dma 



THe pcl816_ai_setup_dma() and pcl816_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 fe4a22a0

drivers/staging/comedi/drivers/pcl816.c

+11 −32
Original line number Diff line number Diff line
@@ -142,47 +142,22 @@ static void pcl816_start_pacer(struct comedi_device *dev, bool load_counters) 
}



static void pcl816_ai_setup_dma(struct comedi_device *dev,

				struct comedi_subdevice *s)

{

	struct pcl816_private *devpriv = dev->private;

	struct comedi_isadma *dma = devpriv->dma;

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

	unsigned int nsamples;



	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 pcl816_ai_setup_next_dma(struct comedi_device *dev,

				struct comedi_subdevice *s,

				unsigned int unread_samples)

{

	struct pcl816_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);
@@ -321,7 +296,9 @@ static irqreturn_t pcl816_interrupt(int irq, void *d) 
	bufptr = devpriv->ai_poll_ptr;

	devpriv->ai_poll_ptr = 0;



	pcl816_ai_setup_next_dma(dev, s, nsamples);

	/* restart dma with the next buffer */

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

	pcl816_ai_setup_dma(dev, s, nsamples);



	transfer_from_dma_buf(dev, s, desc->virt_addr, bufptr, nsamples);
@@ -485,7 +462,9 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) 
	devpriv->ai_poll_ptr = 0;

	devpriv->ai_cmd_canceled = 0;



	pcl816_ai_setup_dma(dev, s);

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

	dma->cur_dma = 0;

	pcl816_ai_setup_dma(dev, s, 0);



	pcl816_start_pacer(dev, true);