Introduce a helper function to program the ISA DMA controller. Program
the ISA DMA as described in Documentation/DMA-ISA-LPC.txt.
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>
void *virt_addr; /* virtual address of DMA buffer */
dma_addr_t hw_addr; /* hardware (bus) address of DMA buffer */
unsigned int size; /* transfer size (in bytes) */
void *virt_addr; /* virtual address of DMA buffer */
dma_addr_t hw_addr; /* hardware (bus) address of DMA buffer */
unsigned int size; /* transfer size (in bytes) */
+ char mode; /* DMA_MODE_* */
};
struct dt282x_private {
};
struct dt282x_private {
+static void dt282x_isadma_program(struct dt282x_dma_desc *dma)
+{
+ unsigned long flags;
+
+ flags = claim_dma_lock();
+ clear_dma_ff(dma->chan);
+ set_dma_mode(dma->chan, dma->mode);
+ set_dma_addr(dma->chan, dma->hw_addr);
+ set_dma_count(dma->chan, dma->size);
+ enable_dma(dma->chan);
+ release_dma_lock(flags);
+}
+
static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n)
{
struct dt282x_private *devpriv = dev->private;
struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index];
static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n)
{
struct dt282x_private *devpriv = dev->private;
struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index];
if (!devpriv->ntrig)
return 0;
if (!devpriv->ntrig)
return 0;
devpriv->ntrig -= n / 2;
dma->size = n;
devpriv->ntrig -= n / 2;
dma->size = n;
+ dma->mode = DMA_MODE_READ;
- set_dma_mode(dma->chan, DMA_MODE_READ);
- flags = claim_dma_lock();
- clear_dma_ff(dma->chan);
- set_dma_addr(dma->chan, dma->hw_addr);
- set_dma_count(dma->chan, dma->size);
- release_dma_lock(flags);
-
- enable_dma(dma->chan);
+ dt282x_isadma_program(dma);
{
struct dt282x_private *devpriv = dev->private;
struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index];
{
struct dt282x_private *devpriv = dev->private;
struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index];
+ dma->mode = DMA_MODE_WRITE;
- set_dma_mode(dma->chan, DMA_MODE_WRITE);
- flags = claim_dma_lock();
- clear_dma_ff(dma->chan);
- set_dma_addr(dma->chan, dma->hw_addr);
- set_dma_count(dma->chan, dma->size);
- release_dma_lock(flags);
-
- enable_dma(dma->chan);
+ dt282x_isadma_program(dma);