diff options
| author | H Hartley Sweeten <hsweeten@visionengravers.com> | 2016-04-14 16:58:07 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-29 05:17:28 (GMT) |
| commit | 6f7fa704648e69a295f6b8bcf35538692258fbb3 (patch) | |
| tree | 0506b040fb3d49e4bf94729e6e1b7bcba251f528 | |
| parent | bbd962206c6002005a827d34d91005cbfbf9dddc (diff) | |
| download | linux-6f7fa704648e69a295f6b8bcf35538692258fbb3.tar.xz | |
staging: comedi: ni_mio_common: introduce NI_STC_DMA_CHAN_SEL()
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@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/comedi/drivers/ni_mio_common.c | 29 |
1 files 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)); |