diff options
| -rw-r--r-- | drivers/staging/comedi/drivers/ni_labpc_isadma.c | 41 |
1 files changed, 24 insertions, 17 deletions
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.c b/drivers/staging/comedi/drivers/ni_labpc_isadma.c index 0ce8aad2f342..862fb7edb33d 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 unsigned int labpc_isadma_disable(struct labpc_dma_desc *dma) +{ + unsigned long flags; + unsigned int residue; + + flags = claim_dma_lock(); + disable_dma(dma->chan); + residue = get_dma_residue(dma->chan); + release_dma_lock(flags); + + return residue; +} + /* utility function that suggests a dma transfer size in bytes */ static unsigned int labpc_suggest_transfer_size(struct comedi_device *dev, struct comedi_subdevice *s) @@ -67,10 +80,10 @@ void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s) unsigned long irq_flags; irq_flags = claim_dma_lock(); - disable_dma(dma->chan); /* 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); @@ -99,20 +112,16 @@ void labpc_drain_dma(struct comedi_device *dev) status = devpriv->stat1; - flags = claim_dma_lock(); - disable_dma(dma->chan); - /* clear flip-flop to make sure 2-byte registers for - * count and address get set correctly */ - clear_dma_ff(dma->chan); - - /* figure out how many points to read */ - max_points = dma->size / sample_size; - /* residue is the number of points left to be done on the dma + /* + * residue is the number of bytes left to be done on the dma * transfer. It should always be zero at this point unless * the stop_src is set to external triggering. */ - residue = get_dma_residue(dma->chan) / sample_size; - num_points = max_points - residue; + residue = labpc_isadma_disable(dma); + + /* figure out how many points to read */ + max_points = dma->size / sample_size; + num_points = max_points - comedi_bytes_to_samples(s, residue); if (cmd->stop_src == TRIG_COUNT && devpriv->count < num_points) num_points = devpriv->count; @@ -132,6 +141,8 @@ void labpc_drain_dma(struct comedi_device *dev) devpriv->count -= num_points; /* set address and count for next transfer */ + 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, leftover * sample_size); release_dma_lock(flags); @@ -170,7 +181,6 @@ void labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan) { struct labpc_private *devpriv = dev->private; struct labpc_dma_desc *dma = &devpriv->dma_desc; - unsigned long dma_flags; if (dma_chan != 1 && dma_chan != 3) return; @@ -187,10 +197,7 @@ void labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan) dma->chan = dma_chan; - dma_flags = claim_dma_lock(); - disable_dma(dma->chan); - set_dma_mode(dma->chan, DMA_MODE_READ); - release_dma_lock(dma_flags); + labpc_isadma_disable(dma); } EXPORT_SYMBOL_GPL(labpc_init_dma_chan); |