For aesthetics, introduce a struct to hold the DMA descriptor data.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/pcl818.c | 44 +++++++++++++++++++--------------
1 file changed, 25 insertions(+), 19 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl818.c b/drivers/staging/comedi/drivers/pcl818.c
index beb03ec..f34c5cc0 100644
--- a/drivers/staging/comedi/drivers/pcl818.c
+++ b/drivers/staging/comedi/drivers/pcl818.c
@@ -302,13 +302,17 @@ static const struct pcl818_board boardtypes[] = {
},
};
+struct pcl818_dma_desc {
+ unsigned long dmabuf; /* pointers to begin of DMA buffers */
+ unsigned int hwdmaptr; /* hardware address of DMA buffers */
+};
+
struct pcl818_private {
unsigned int dma; /* used DMA, 0=don't use DMA */
unsigned int dmapages;
unsigned int hwdmasize;
- unsigned long dmabuf[2]; /* pointers to begin of DMA buffers */
- unsigned int hwdmaptr[2]; /* hardware address of DMA buffers */
- int next_dma_buf; /* which DMA buffer will be used next round */
+ struct pcl818_dma_desc dma_desc[2];
+ int cur_dma;
long dma_runs_to_end; /* how many we must permorm DMA transfer to end of record */
unsigned long last_dma_run; /* how many bytes we must transfer on last DMA page */
unsigned int ns_min; /* manimal allowed delay between samples (in us) for actual card */
@@ -343,6 +347,7 @@ static void pcl818_ai_setup_dma(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct pcl818_private *devpriv = dev->private;
+ struct pcl818_dma_desc *dma = &devpriv->dma_desc[0];
struct comedi_cmd *cmd = &s->async->cmd;
unsigned int flags;
unsigned int bytes;
@@ -358,11 +363,11 @@ static void pcl818_ai_setup_dma(struct comedi_device *dev,
bytes = devpriv->hwdmasize;
}
- devpriv->next_dma_buf = 0;
+ devpriv->cur_dma = 0;
set_dma_mode(devpriv->dma, DMA_MODE_READ);
flags = claim_dma_lock();
clear_dma_ff(devpriv->dma);
- set_dma_addr(devpriv->dma, devpriv->hwdmaptr[0]);
+ set_dma_addr(devpriv->dma, dma->hwdmaptr);
set_dma_count(devpriv->dma, bytes);
release_dma_lock(flags);
enable_dma(devpriv->dma);
@@ -373,16 +378,17 @@ static void pcl818_ai_setup_next_dma(struct comedi_device *dev,
{
struct pcl818_private *devpriv = dev->private;
struct comedi_cmd *cmd = &s->async->cmd;
+ struct pcl818_dma_desc *dma;
unsigned long flags;
disable_dma(devpriv->dma);
- devpriv->next_dma_buf = 1 - devpriv->next_dma_buf;
+ devpriv->cur_dma = 1 - devpriv->cur_dma;
if (devpriv->dma_runs_to_end > -1 || cmd->stop_src == TRIG_NONE) {
/* switch dma bufs */
+ dma = &devpriv->dma_desc[devpriv->cur_dma];
set_dma_mode(devpriv->dma, DMA_MODE_READ);
flags = claim_dma_lock();
- set_dma_addr(devpriv->dma,
- devpriv->hwdmaptr[devpriv->next_dma_buf]);
+ set_dma_addr(devpriv->dma, dma->hwdmaptr);
if (devpriv->dma_runs_to_end || cmd->stop_src == TRIG_NONE)
set_dma_count(devpriv->dma, devpriv->hwdmasize);
else
@@ -558,15 +564,14 @@ static void pcl818_handle_dma(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct pcl818_private *devpriv = dev->private;
- unsigned short *ptr;
+ struct pcl818_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];
+ unsigned short *ptr = (unsigned short *)dma->dmabuf;
unsigned int chan;
unsigned int val;
int i, len, bufptr;
pcl818_ai_setup_next_dma(dev, s);
- ptr = (unsigned short *)devpriv->dmabuf[1 - devpriv->next_dma_buf];
-
len = devpriv->hwdmasize >> 1;
bufptr = 0;
@@ -1057,6 +1062,7 @@ static void pcl818_set_ai_range_table(struct comedi_device *dev,
static int pcl818_alloc_dma(struct comedi_device *dev, unsigned int dma_chan)
{
struct pcl818_private *devpriv = dev->private;
+ struct pcl818_dma_desc *dma;
int i;
if (!(dma_chan == 3 || dma_chan == 1))
@@ -1070,14 +1076,12 @@ static int pcl818_alloc_dma(struct comedi_device *dev, unsigned int dma_chan)
devpriv->hwdmasize = (1 << devpriv->dmapages) * PAGE_SIZE;
for (i = 0; i < 2; i++) {
- unsigned long dmabuf;
+ dma = &devpriv->dma_desc[i];
- dmabuf = __get_dma_pages(GFP_KERNEL, devpriv->dmapages);
- if (!dmabuf)
+ dma->dmabuf = __get_dma_pages(GFP_KERNEL, devpriv->dmapages);
+ if (!dma->dmabuf)
return -ENOMEM;
-
- devpriv->dmabuf[i] = dmabuf;
- devpriv->hwdmaptr[i] = virt_to_bus((void *)dmabuf);
+ dma->hwdmaptr = virt_to_bus((void *)dma->dmabuf);
}
return 0;
}
@@ -1085,6 +1089,7 @@ static int pcl818_alloc_dma(struct comedi_device *dev, unsigned int dma_chan)
static void pcl818_free_dma(struct comedi_device *dev)
{
struct pcl818_private *devpriv = dev->private;
+ struct pcl818_dma_desc *dma;
int i;
if (!devpriv)
@@ -1093,8 +1098,9 @@ static void pcl818_free_dma(struct comedi_device *dev)
if (devpriv->dma)
free_dma(devpriv->dma);
for (i = 0; i < 2; i++) {
- if (devpriv->dmabuf[i])
- free_pages(devpriv->dmabuf[i], devpriv->dmapages);
+ dma = &devpriv->dma_desc[i];
+ if (dma->dmabuf)
+ free_pages(dma->dmabuf, devpriv->dmapages);
}
}
--
2.0.3
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