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 <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/staging/comedi/drivers/das1800.c | 52 +++++++++++++++-----------------
1 file changed, 25 insertions(+), 27 deletions(-)
diff --git a/drivers/staging/comedi/drivers/das1800.c
b/drivers/staging/comedi/drivers/das1800.c
index 2d376fd..df28d36a 100644
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -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;
}
--
2.0.3
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