The inline helper ni_stc_dma_channel_select_bitfield() returns the
bits needed to select a MITE channel to use for DMA. The MITE code
is setup to handle up to 8 channels but in reality only channels 0
to 3 are used by most of the drivers. The PCI-6032E and PCI-6033E
boards can also use channels 4 and 5.
For aesthetics, convert this inline function into a macro and
remove the BUG() which will never occur.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/ni_mio_common.c | 29 ++++++++++----------------
1 file changed, 11 insertions(+), 18 deletions(-)
diff --git a/drivers/staging/comedi/drivers/ni_mio_common.c b/drivers/staging/comedi/drivers/ni_mio_common.c
index d331386..081ed3f 100644
--- a/drivers/staging/comedi/drivers/ni_mio_common.c
+++ b/drivers/staging/comedi/drivers/ni_mio_common.c
@@ -560,20 +560,13 @@ static inline void ni_set_bitfield(struct comedi_device *dev, int reg,
}
#ifdef PCIDMA
-/* DMA channel setup */
-static inline unsigned int
-ni_stc_dma_channel_select_bitfield(unsigned int channel)
-{
- if (channel < 4)
- return 1 << channel;
- if (channel == 4)
- return 0x3;
- if (channel == 5)
- return 0x5;
- BUG();
- return 0;
-}
+/* selects the MITE channel to use for DMA */
+#define NI_STC_DMA_CHAN_SEL(x) (((x) < 4) ? BIT(x) : \
+ ((x) == 4) ? 0x3 : \
+ ((x) == 5) ? 0x5 : 0x0)
+
+/* DMA channel setup */
static int ni_request_ai_mite_channel(struct comedi_device *dev)
{
struct ni_private *devpriv = dev->private;
@@ -592,7 +585,7 @@ static int ni_request_ai_mite_channel(struct comedi_device *dev)
mite_chan->dir = COMEDI_INPUT;
devpriv->ai_mite_chan = mite_chan;
- bits = ni_stc_dma_channel_select_bitfield(mite_chan->channel);
+ bits = NI_STC_DMA_CHAN_SEL(mite_chan->channel);
ni_set_bitfield(dev, NI_E_DMA_AI_AO_SEL_REG,
NI_E_DMA_AI_SEL_MASK, NI_E_DMA_AI_SEL(bits));
@@ -618,7 +611,7 @@ static int ni_request_ao_mite_channel(struct comedi_device *dev)
mite_chan->dir = COMEDI_OUTPUT;
devpriv->ao_mite_chan = mite_chan;
- bits = ni_stc_dma_channel_select_bitfield(mite_chan->channel);
+ bits = NI_STC_DMA_CHAN_SEL(mite_chan->channel);
ni_set_bitfield(dev, NI_E_DMA_AI_AO_SEL_REG,
NI_E_DMA_AO_SEL_MASK, NI_E_DMA_AO_SEL(bits));
@@ -648,7 +641,7 @@ static int ni_request_gpct_mite_channel(struct comedi_device *dev,
mite_chan->dir = direction;
ni_tio_set_mite_channel(counter, mite_chan);
- bits = ni_stc_dma_channel_select_bitfield(mite_chan->channel);
+ bits = NI_STC_DMA_CHAN_SEL(mite_chan->channel);
ni_set_bitfield(dev, NI_E_DMA_G0_G1_SEL_REG,
NI_E_DMA_G0_G1_SEL_MASK(gpct_index),
NI_E_DMA_G0_G1_SEL(gpct_index, bits));
@@ -676,12 +669,12 @@ static int ni_request_cdo_mite_channel(struct comedi_device *dev)
devpriv->cdo_mite_chan = mite_chan;
/*
- * XXX just guessing ni_stc_dma_channel_select_bitfield()
+ * XXX just guessing NI_STC_DMA_CHAN_SEL()
* returns the right bits, under the assumption the cdio dma
* selection works just like ai/ao/gpct.
* Definitely works for dma channels 0 and 1.
*/
- bits = ni_stc_dma_channel_select_bitfield(mite_chan->channel);
+ bits = NI_STC_DMA_CHAN_SEL(mite_chan->channel);
ni_set_bitfield(dev, NI_M_CDIO_DMA_SEL_REG,
NI_M_CDIO_DMA_SEL_CDO_MASK,
NI_M_CDIO_DMA_SEL_CDO(bits));
--
2.6.3
_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
