[PATCH 23/25] staging: comedi: ni_labpc_isadma: introduce labpc_isadma_program()
H Hartley Sweeten
hsweeten at visionengravers.com
Tue Jan 13 17:16:42 UTC 2015
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 at visionengravers.com>
Cc: Ian Abbott <abbotti at mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
drivers/staging/comedi/drivers/ni_labpc_isadma.c | 37 ++++++++++++------------
1 file changed, 18 insertions(+), 19 deletions(-)
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
index af13f4b..3100549 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.c
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
@@ -31,6 +31,19 @@
/* size in bytes of dma buffer */
#define LABPC_ISADMA_BUFFER_SIZE 0xff00
+static void labpc_isadma_program(struct labpc_dma_desc *dma)
+{
+ unsigned long flags;
+
+ flags = claim_dma_lock();
+ clear_dma_ff(dma->chan);
+ set_dma_mode(dma->chan, DMA_MODE_READ);
+ set_dma_addr(dma->chan, dma->hw_addr);
+ set_dma_count(dma->chan, dma->size);
+ enable_dma(dma->chan);
+ release_dma_lock(flags);
+}
+
static unsigned int labpc_isadma_disable(struct labpc_dma_desc *dma)
{
unsigned long flags;
@@ -77,22 +90,15 @@ void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s)
struct labpc_dma_desc *dma = &devpriv->dma_desc;
struct comedi_cmd *cmd = &s->async->cmd;
unsigned int sample_size = comedi_bytes_per_sample(s);
- unsigned long irq_flags;
- irq_flags = claim_dma_lock();
- /* clear flip-flop to make sure 2-byte registers for
- * count and address get set correctly */
- clear_dma_ff(dma->chan);
- set_dma_mode(dma->chan, DMA_MODE_READ);
- set_dma_addr(dma->chan, dma->hw_addr);
/* set appropriate size of transfer */
dma->size = labpc_suggest_transfer_size(dev, s);
if (cmd->stop_src == TRIG_COUNT &&
devpriv->count * sample_size < dma->size)
dma->size = devpriv->count * sample_size;
- set_dma_count(dma->chan, dma->size);
- enable_dma(dma->chan);
- release_dma_lock(irq_flags);
+
+ labpc_isadma_program(dma);
+
/* set CMD3 bits for caller to enable DMA and interrupt */
devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);
}
@@ -145,18 +151,11 @@ static void handle_isa_dma(struct comedi_device *dev)
{
struct labpc_private *devpriv = dev->private;
struct labpc_dma_desc *dma = &devpriv->dma_desc;
- unsigned long flags;
labpc_drain_dma(dev);
- if (dma->size) {
- flags = claim_dma_lock();
- set_dma_mode(dma->chan, DMA_MODE_READ);
- set_dma_addr(dma->chan, dma->hw_addr);
- set_dma_count(dma->chan, dma->size);
- enable_dma(dma->chan);
- release_dma_lock(flags);
- }
+ if (dma->size)
+ labpc_isadma_program(dma);
/* clear dma tc interrupt */
devpriv->write_byte(dev, 0x1, DMATC_CLEAR_REG);
--
2.0.3
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