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Commit ee34785c authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcl816: clarify dma channel request in pcl816_attach() 



All the board types can do DMA using DMA channels 3 or 1. Remove the 'DMAbits',
which is a mask of the valid channels, from the boardinfo.

Refactor pcl816_attach() to remove the need for the goto.

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 27f3f4d4

drivers/staging/comedi/drivers/pcl816.c

+7 −26
Original line number Diff line number Diff line
@@ -100,7 +100,6 @@ struct pcl816_board { 
	int n_dochan;

	const struct comedi_lrange *ai_range_type;

	unsigned int IRQbits;

	unsigned int DMAbits;

	int ai_maxdata;

	int ao_maxdata;

	int ai_chanlist;
@@ -118,7 +117,6 @@ static const struct pcl816_board boardtypes[] = { 
		.n_dochan	= 16,

		.ai_range_type	= &range_pcl816,

		.IRQbits	= 0x00fc,

		.DMAbits	= 0x0a,

		.ai_maxdata	= 0xffff,

		.ao_maxdata	= 0xffff,

		.ai_chanlist	= 1024,
@@ -133,7 +131,6 @@ static const struct pcl816_board boardtypes[] = { 
		.n_dochan	= 16,

		.ai_range_type	= &range_pcl816,

		.IRQbits	= 0x00fc,

		.DMAbits	= 0x0a,

		.ai_maxdata	= 0x3fff,

		.ao_maxdata	= 0x3fff,

		.ai_chanlist	= 1024,
@@ -866,7 +863,6 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
	const struct pcl816_board *board = comedi_board(dev);

	struct pcl816_private *devpriv;

	int ret;

	unsigned int dma;

	unsigned long pages;

	/* int i; */

	struct comedi_subdevice *s;
@@ -894,30 +890,17 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
	devpriv->irq_blocked = 0;	/* number of subdevice which use IRQ */

	devpriv->int816_mode = 0;	/* mode of irq */



	/* grab our DMA */

	dma = 0;

	devpriv->dma = dma;

	if (!dev->irq)

		goto no_dma;	/* if we haven't IRQ, we can't use DMA */



	if (board->DMAbits != 0) {	/* board support DMA */

		dma = it->options[2];

		if (dma < 1)

			goto no_dma;	/* DMA disabled */



		if (((1 << dma) & board->DMAbits) == 0) {

			dev_err(dev->class_dev,

				"DMA is out of allowed range, FAIL!\n");

			return -EINVAL;	/* Bad DMA */

		}

		ret = request_dma(dma, dev->board_name);

	/* we need an IRQ to do DMA on channel 3 or 1 */

	if (dev->irq && (it->options[2] == 3 || it->options[2] == 1)) {

		ret = request_dma(it->options[2], dev->board_name);

		if (ret) {

			dev_err(dev->class_dev,

				"unable to allocate DMA %u, FAIL!\n", dma);

			return -EBUSY;	/* DMA isn't free */

				"unable to request DMA channel %d\n",

				it->options[2]);

			return -EBUSY;

		}

		devpriv->dma = it->options[2];



		devpriv->dma = dma;

		pages = 2;	/* we need 16KB */

		devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages);
@@ -945,8 +928,6 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
		devpriv->hwdmasize[1] = (1 << pages) * PAGE_SIZE;

	}



no_dma:



/*  if (board->n_aochan > 0)

    subdevs[1] = COMEDI_SUBD_AO;

  if (board->n_dichan > 0)