Commit 6e89008b authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: das1800: tidy up das1800_init_dma() 



Refactor this function so that a for loop can be used to request and
set up the two DMA descriptors.

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 fd8aab1a

drivers/staging/comedi/drivers/das1800.c

+25 −27
Original line number Diff line number Diff line
@@ -1228,15 +1228,24 @@ static int das1800_do_wbits(struct comedi_device *dev, 
	return insn->n;

}



static int das1800_init_dma(struct comedi_device *dev, unsigned int dma0,

			    unsigned int dma1)

static int das1800_init_dma(struct comedi_device *dev,

			    struct comedi_devconfig *it)

{

	struct das1800_private *devpriv = dev->private;

	struct das1800_dma_desc *dma;

	unsigned int *dma_chan;

	unsigned long flags;

	int i;



	/*

	 * it->options[2] is DMA channel 0

	 * it->options[3] is DMA channel 1

	 *

	 * Encode the DMA channels into 2 digit hexadecimal for switch.

	 */

	dma_chan = &it->options[2];



	/* encode dma0 and dma1 into 2 digit hexadecimal for switch */

	switch ((dma0 & 0x7) | (dma1 << 4)) {

	switch ((dma_chan[0] & 0x7) | (dma_chan[1] << 4)) {

	case 0x5:	/*  dma0 == 5 */

		devpriv->dma_bits |= DMA_CH5;

		break;
@@ -1265,33 +1274,24 @@ static int das1800_init_dma(struct comedi_device *dev, unsigned int dma0, 
		return -EINVAL;

	}



	dma = &devpriv->dma_desc[0];

	if (request_dma(dma0, dev->driver->driver_name)) {

		dev_err(dev->class_dev,

			"failed to allocate dma channel %i\n", dma0);

		return -EINVAL;

	}

	dma->chan = dma0;

	dma->virt_addr = kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA);

	if (!dma->virt_addr)

		return -ENOMEM;

	flags = claim_dma_lock();

	disable_dma(dma->chan);

	set_dma_mode(dma->chan, DMA_MODE_READ);

	release_dma_lock(flags);

	for (i = 0; i < 2; i++) {

		dma = &devpriv->dma_desc[i];



	if (dma1) {

		dma = &devpriv->dma_desc[1];

		if (request_dma(dma1, dev->driver->driver_name)) {

		if (dma_chan[i] == 0)

			break;



		if (request_dma(dma_chan[i], dev->board_name)) {

			dev_err(dev->class_dev,

				"failed to allocate dma channel %i\n",

				dma1);

				dma_chan[i]);

			return -EINVAL;

		}

		dma->chan = dma1;

		dma->chan = dma_chan[i];



		dma->virt_addr = kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA);

		if (!dma->virt_addr)

			return -ENOMEM;



		flags = claim_dma_lock();

		disable_dma(dma->chan);

		set_dma_mode(dma->chan, DMA_MODE_READ);
@@ -1366,8 +1366,6 @@ static int das1800_attach(struct comedi_device *dev, 
	struct das1800_private *devpriv;

	struct comedi_subdevice *s;

	unsigned int irq = it->options[1];

	unsigned int dma0 = it->options[2];

	unsigned int dma1 = it->options[3];

	int board;

	int ret;
@@ -1430,8 +1428,8 @@ static int das1800_attach(struct comedi_device *dev, 
	}



	/* an irq and one dma channel is required to use dma */

	if (dev->irq & dma0) {

		ret = das1800_init_dma(dev, dma0, dma1);

	if (dev->irq & it->options[2]) {

		ret = das1800_init_dma(dev, it);

		if (ret < 0)

			return ret;

	}