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staging: comedi: das1800: tidy up das1800_init_dma()

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

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
H Hartley Sweeten 2015-01-12 10:55:43 -07:00 committed by Greg Kroah-Hartman
parent fd8aab1a9c
commit 6e89008b06
1 changed files with 25 additions and 27 deletions
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52
drivers/staging/comedi/drivers/das1800.c
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@ -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;
/* encode dma0 and dma1 into 2 digit hexadecimal for switch */
switch ((dma0 & 0x7) | (dma1 << 4)) {
/*
* 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];
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;
}