Migrate the code for setting up an ISA DMA transfer into a new function
`labpc_setup_dma()` in the "ni_labpc_isadma" module. Provide a dummy
inline function in "ni_labpc_isadma.h" if the "ni_labpc_isadma" module
is not being built.
The static function `labpc_suggest_transfer_size()` also needs to move
across to the new module.
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/drivers/ni_labpc.c | 53 +-----------------------
drivers/staging/comedi/drivers/ni_labpc_isadma.c | 51 +++++++++++++++++++++++
drivers/staging/comedi/drivers/ni_labpc_isadma.h | 6 +++
3 files changed, 59 insertions(+), 51 deletions(-)
diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index c0ab71e..39cdfda 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -386,32 +386,6 @@ static int labpc_ai_insn_read(struct comedi_device *dev,
return insn->n;
}
-#ifdef CONFIG_ISA_DMA_API
-/* utility function that suggests a dma transfer size in bytes */
-static unsigned int labpc_suggest_transfer_size(const struct comedi_cmd *cmd)
-{
- unsigned int size;
- unsigned int freq;
-
- if (cmd->convert_src == TRIG_TIMER)
- freq = 1000000000 / cmd->convert_arg;
- /* return some default value */
- else
- freq = 0xffffffff;
-
- /* make buffer fill in no more than 1/3 second */
- size = (freq / 3) * sample_size;
-
- /* set a minimum and maximum size allowed */
- if (size > dma_buffer_size)
- size = dma_buffer_size - dma_buffer_size % sample_size;
- else if (size < sample_size)
- size = sample_size;
-
- return size;
-}
-#endif
-
static bool labpc_use_continuous_mode(const struct comedi_cmd *cmd,
enum scan_mode mode)
{
@@ -882,31 +856,8 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
labpc_clear_adc_fifo(dev);
-#ifdef CONFIG_ISA_DMA_API
- /* set up dma transfer */
- if (xfer == isa_dma_transfer) {
- unsigned long irq_flags;
-
- irq_flags = claim_dma_lock();
- disable_dma(devpriv->dma_chan);
- /* clear flip-flop to make sure 2-byte registers for
- * count and address get set correctly */
- clear_dma_ff(devpriv->dma_chan);
- set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);
- /* set appropriate size of transfer */
- devpriv->dma_transfer_size = labpc_suggest_transfer_size(cmd);
- if (cmd->stop_src == TRIG_COUNT &&
- devpriv->count * sample_size < devpriv->dma_transfer_size) {
- devpriv->dma_transfer_size =
- devpriv->count * sample_size;
- }
- set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
- enable_dma(devpriv->dma_chan);
- release_dma_lock(irq_flags);
- /* enable board's dma */
- devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);
- }
-#endif
+ if (xfer == isa_dma_transfer)
+ labpc_setup_dma(dev, s);
/* enable error interrupts */
devpriv->cmd3 |= CMD3_ERRINTEN;
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
index a052974..dba2be3 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.c
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.c
@@ -29,6 +29,57 @@
/* size in bytes of dma buffer */
static const int dma_buffer_size = 0xff00;
+/* 2 bytes per sample */
+static const int sample_size = 2;
+
+/* utility function that suggests a dma transfer size in bytes */
+static unsigned int labpc_suggest_transfer_size(const struct comedi_cmd *cmd)
+{
+ unsigned int size;
+ unsigned int freq;
+
+ if (cmd->convert_src == TRIG_TIMER)
+ freq = 1000000000 / cmd->convert_arg;
+ else
+ /* return some default value */
+ freq = 0xffffffff;
+
+ /* make buffer fill in no more than 1/3 second */
+ size = (freq / 3) * sample_size;
+
+ /* set a minimum and maximum size allowed */
+ if (size > dma_buffer_size)
+ size = dma_buffer_size - dma_buffer_size % sample_size;
+ else if (size < sample_size)
+ size = sample_size;
+
+ return size;
+}
+
+void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s)
+{
+ struct labpc_private *devpriv = dev->private;
+ struct comedi_cmd *cmd = &s->async->cmd;
+ unsigned long irq_flags;
+
+ irq_flags = claim_dma_lock();
+ disable_dma(devpriv->dma_chan);
+ /* clear flip-flop to make sure 2-byte registers for
+ * count and address get set correctly */
+ clear_dma_ff(devpriv->dma_chan);
+ set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);
+ /* set appropriate size of transfer */
+ devpriv->dma_transfer_size = labpc_suggest_transfer_size(cmd);
+ if (cmd->stop_src == TRIG_COUNT &&
+ devpriv->count * sample_size < devpriv->dma_transfer_size)
+ devpriv->dma_transfer_size = devpriv->count * sample_size;
+ set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
+ enable_dma(devpriv->dma_chan);
+ release_dma_lock(irq_flags);
+ /* set CMD3 bits for caller to enable DMA and interrupt */
+ devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);
+}
+EXPORT_SYMBOL_GPL(labpc_setup_dma);
int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan)
{
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.h b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
index 3b022ea..c721f57 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.h
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
@@ -18,6 +18,7 @@ static inline bool labpc_have_dma_chan(struct comedi_device *dev)
int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);
void labpc_free_dma_chan(struct comedi_device *dev);
+void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s);
#else
@@ -36,6 +37,11 @@ static inline void labpc_free_dma_chan(struct comedi_device *dev)
{
}
+static inline void labpc_setup_dma(struct comedi_device *dev,
+ struct comedi_subdevice *s)
+{
+}
+
#endif
#endif /* _NI_LABPC_ISADMA_H */
--
1.8.2.1
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