Commit 7cbb0ef9 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: ni_at_a2150: introduce a2150_alloc_irq_dma() 



This driver requires an IRQ and DMA in order to support async commands.

For aesthetics, introduce a helper function to request the IRQ and DMA
channels and allocate the DMA buffer. Since the async command support
is optional, make the helper function handle any request/allocation
errors and allow the driver to still attach without async command support.

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 2447a27c

drivers/staging/comedi/drivers/ni_at_a2150.c

+46 −28
Original line number Diff line number Diff line
@@ -676,6 +676,50 @@ static int a2150_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, 
	return n;

}



static void a2150_alloc_irq_dma(struct comedi_device *dev,

				struct comedi_devconfig *it)

{

	struct a2150_private *devpriv = dev->private;

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

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



	/*

	 * Only IRQs 15, 14, 12-9, and 7-3 are valid.

	 * Only DMA channels 7-5 and 3-0 are valid.

	 *

	 * Both must be valid for async command support.

	 */

	if (irq_num > 15 || dma_chan > 7 ||

	    !((1 << irq_num) & 0xdef8) || !((1 << dma_chan) & 0xef))

		return;



	/*

	 * Request the IRQ and DMA channels and allocate the DMA buffer.

	 * If the requests or allocation fail async command supprt will

	 * not be available.

	 */

	if (request_irq(irq_num, a2150_interrupt, 0, dev->board_name, dev))

		return;

	if (request_dma(dma_chan, dev->board_name)) {

		free_irq(irq_num, dev);

		return;

	}

	devpriv->dma_buffer = kmalloc(A2150_DMA_BUFFER_SIZE,

				      GFP_KERNEL | GFP_DMA);

	if (!devpriv->dma_buffer) {

		free_dma(dma_chan);

		free_irq(irq_num, dev);

		return;

	}



	dev->irq = irq_num;

	devpriv->dma = dma_chan;

	devpriv->irq_dma_bits = IRQ_LVL_BITS(irq_num) | DMA_CHAN_BITS(dma_chan);



	disable_dma(dma_chan);

	set_dma_mode(dma_chan, DMA_MODE_READ);

}



/* probes board type, returns offset */

static int a2150_probe(struct comedi_device *dev)

{
@@ -689,8 +733,6 @@ static int a2150_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
	const struct a2150_board *thisboard;

	struct a2150_private *devpriv;

	struct comedi_subdevice *s;

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

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

	static const int timeout = 2000;

	int i;

	int ret;
@@ -711,31 +753,7 @@ static int a2150_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
	thisboard = dev->board_ptr;

	dev->board_name = thisboard->name;



	if ((irq >= 3 && irq <= 7) || (irq >= 9 && irq <= 12) ||

	    irq == 14 || irq == 15) {

		ret = request_irq(irq, a2150_interrupt, 0,

				  dev->board_name, dev);

		if (ret == 0) {

			devpriv->irq_dma_bits |= IRQ_LVL_BITS(irq);

			dev->irq = irq;

		}

	}



	if (dev->irq && dma <= 7 && dma != 4) {

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

		if (ret == 0) {

			devpriv->dma = dma;

			devpriv->dma_buffer = kmalloc(A2150_DMA_BUFFER_SIZE,

						      GFP_KERNEL | GFP_DMA);

			if (!devpriv->dma_buffer)

				return -ENOMEM;



			disable_dma(dma);

			set_dma_mode(dma, DMA_MODE_READ);



			devpriv->irq_dma_bits |= DMA_CHAN_BITS(dma);

		}

	}

	a2150_alloc_irq_dma(dev, it);



	ret = comedi_alloc_subdevices(dev, 1);

	if (ret)
@@ -749,7 +767,7 @@ static int a2150_attach(struct comedi_device *dev, struct comedi_devconfig *it) 
	s->maxdata = 0xffff;

	s->range_table = &range_a2150;

	s->insn_read = a2150_ai_rinsn;

	if (dev->irq && devpriv->dma) {

	if (dev->irq) {

		dev->read_subdev = s;

		s->subdev_flags |= SDF_CMD_READ;

		s->len_chanlist = s->n_chan;

CRA Git | Maintained and supported by SUSTech CRA and CCSE