Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4ba4a2d3 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: pcl818: clarify dma channel request in pcl818_attach() 



All the board types that can do DMA can use DMA channels 3 or 1. Remove
the 'DMAbits', which is a mask of the valid channels, from the boardinfo
and replace it with a bit-field flag 'has_dma'.

Refactor pcl818_attach() to use the new flag and 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 ee34785c

drivers/staging/comedi/drivers/pcl818.c

+18 −27
Original line number Diff line number Diff line
@@ -267,9 +267,9 @@ struct pcl818_board { 
	int n_dochan;

	const struct comedi_lrange *ai_range_type;

	unsigned int IRQbits;

	unsigned int DMAbits;

	int ai_maxdata;

	int ao_maxdata;

	unsigned int has_dma:1;

	unsigned int has_fifo:1;

	int is_818;

};
@@ -286,9 +286,9 @@ static const struct pcl818_board boardtypes[] = { 
		.n_dochan	= 16,

		.ai_range_type	= &range_pcl818l_l_ai,

		.IRQbits	= 0x00fc,

		.DMAbits	= 0x0a,

		.ai_maxdata	= 0xfff,

		.ao_maxdata	= 0xfff,

		.has_dma	= 1,

		.is_818		= 1,

	}, {

		.name		= "pcl818h",
@@ -301,9 +301,9 @@ static const struct pcl818_board boardtypes[] = { 
		.n_dochan	= 16,

		.ai_range_type	= &range_pcl818h_ai,

		.IRQbits	= 0x00fc,

		.DMAbits	= 0x0a,

		.ai_maxdata	= 0xfff,

		.ao_maxdata	= 0xfff,

		.has_dma	= 1,

		.is_818		= 1,

	}, {

		.name		= "pcl818hd",
@@ -316,9 +316,9 @@ static const struct pcl818_board boardtypes[] = { 
		.n_dochan	= 16,

		.ai_range_type	= &range_pcl818h_ai,

		.IRQbits	= 0x00fc,

		.DMAbits	= 0x0a,

		.ai_maxdata	= 0xfff,

		.ao_maxdata	= 0xfff,

		.has_dma	= 1,

		.has_fifo	= 1,

		.is_818		= 1,

	}, {
@@ -332,9 +332,9 @@ static const struct pcl818_board boardtypes[] = { 
		.n_dochan	= 16,

		.ai_range_type	= &range_pcl818hg_ai,

		.IRQbits	= 0x00fc,

		.DMAbits	= 0x0a,

		.ai_maxdata	= 0xfff,

		.ao_maxdata	= 0xfff,

		.has_dma	= 1,

		.has_fifo	= 1,

		.is_818		= 1,

	}, {
@@ -348,9 +348,9 @@ static const struct pcl818_board boardtypes[] = { 
		.n_dochan	= 16,

		.ai_range_type	= &range_pcl818h_ai,

		.IRQbits	= 0x00fc,

		.DMAbits	= 0x0a,

		.ai_maxdata	= 0xfff,

		.ao_maxdata	= 0xfff,

		.has_dma	= 1,

		.is_818		= 1,

	}, {

		.name		= "pcl718",
@@ -363,9 +363,9 @@ static const struct pcl818_board boardtypes[] = { 
		.n_dochan	= 16,

		.ai_range_type	= &range_unipolar5,

		.IRQbits	= 0x00fc,

		.DMAbits	= 0x0a,

		.ai_maxdata	= 0xfff,

		.ao_maxdata	= 0xfff,

		.has_dma	= 1,

	}, {

		.name		= "pcm3718",

		.n_ranges	= 9,
@@ -376,9 +376,9 @@ static const struct pcl818_board boardtypes[] = { 
		.n_dochan	= 16,

		.ai_range_type	= &range_pcl818h_ai,

		.IRQbits	= 0x00fc,

		.DMAbits	= 0x0a,

		.ai_maxdata	= 0xfff,

		.ao_maxdata	= 0xfff,

		.has_dma	= 1,

		.is_818		= 1,

	},

};
@@ -1315,7 +1315,6 @@ static int pcl818_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
	const struct pcl818_board *board = comedi_board(dev);

	struct pcl818_private *devpriv;

	int ret;

	int dma;

	unsigned long pages;

	struct comedi_subdevice *s;
@@ -1347,24 +1346,18 @@ static int pcl818_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
	devpriv->irq_blocked = 0;	/* number of subdevice which use IRQ */

	devpriv->ai_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) {

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

	if (dev->irq && board->has_dma &&

	    (it->options[2] == 3 || it->options[2] == 1)) {

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

		if (ret) {

			dev_err(dev->class_dev,

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

			return -EINVAL;	/* Bad DMA */

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

				it->options[2]);

			return -EBUSY;

		}

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

		if (ret)

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

		devpriv->dma = dma;

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



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

		devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages);

		if (!devpriv->dmabuf[0])
@@ -1381,8 +1374,6 @@ static int pcl818_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
		devpriv->hwdmasize[1] = (1 << pages) * PAGE_SIZE;

	}



no_dma:



	ret = comedi_alloc_subdevices(dev, 4);

	if (ret)

		return ret;