For aesthetics, introduce a struct to hold the DMA descriptor data.
Signed-off-by: H Hartley Sweeten <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/staging/comedi/drivers/pcl812.c | 100 ++++++++++++++++----------------
1 file changed, 50 insertions(+), 50 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl812.c
b/drivers/staging/comedi/drivers/pcl812.c
index b628f06..d9f94c9 100644
--- a/drivers/staging/comedi/drivers/pcl812.c
+++ b/drivers/staging/comedi/drivers/pcl812.c
@@ -506,6 +506,12 @@ static const struct pcl812_board boardtypes[] = {
},
};
+struct pcl812_dma_desc {
+ unsigned long virt_addr; /* virtual address of DMA buffer */
+ unsigned int hw_addr; /* hardware (bus) address of DMA buffer */
+ unsigned int size; /* transfer size (in bytes) */
+};
+
struct pcl812_private {
unsigned char dma; /* >0 use dma ( usedDMA channel) */
unsigned char range_correction; /* =1 we must add 1 to range number */
@@ -514,10 +520,8 @@ struct pcl812_private {
unsigned int ai_poll_ptr; /* how many sampes transfer poll */
unsigned int dmapages;
unsigned int hwdmasize;
- unsigned long dmabuf[2]; /* PTR to DMA buf */
- unsigned int hwdmaptr[2]; /* HW PTR to DMA buf */
- unsigned int dmabytestomove[2]; /* how many bytes DMA transfer */
- int next_dma_buf; /* which buffer is next to use */
+ struct pcl812_dma_desc dma_desc[2];
+ int cur_dma;
unsigned int dma_runs_to_end; /* how many times we must switch DMA
buffers */
unsigned int last_dma_run; /* how many bytes to transfer on last
DMA buffer */
unsigned int max_812_ai_mode0_rangewait; /* setling time for
gain */
@@ -549,23 +553,23 @@ static void pcl812_ai_setup_dma(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct pcl812_private *devpriv = dev->private;
+ struct pcl812_dma_desc *dma0 = &devpriv->dma_desc[0];
+ struct pcl812_dma_desc *dma1 = &devpriv->dma_desc[1];
struct comedi_cmd *cmd = &s->async->cmd;
unsigned int dma_flags;
unsigned int bytes;
/* we use EOS, so adapt DMA buffer to one scan */
if (devpriv->ai_eos) {
- devpriv->dmabytestomove[0] = comedi_bytes_per_scan(s);
- devpriv->dmabytestomove[1] = comedi_bytes_per_scan(s);
+ dma0->size = comedi_bytes_per_scan(s);
+ dma1->size = comedi_bytes_per_scan(s);
devpriv->dma_runs_to_end = 1;
} else {
- devpriv->dmabytestomove[0] = devpriv->hwdmasize;
- devpriv->dmabytestomove[1] = devpriv->hwdmasize;
+ dma0->size = devpriv->hwdmasize;
+ dma1->size = devpriv->hwdmasize;
if (s->async->prealloc_bufsz < devpriv->hwdmasize) {
- devpriv->dmabytestomove[0] =
- s->async->prealloc_bufsz;
- devpriv->dmabytestomove[1] =
- s->async->prealloc_bufsz;
+ dma0->size = s->async->prealloc_bufsz;
+ dma1->size = s->async->prealloc_bufsz;
}
if (cmd->stop_src == TRIG_NONE) {
devpriv->dma_runs_to_end = 1;
@@ -574,32 +578,29 @@ static void pcl812_ai_setup_dma(struct comedi_device *dev,
bytes = cmd->stop_arg * comedi_bytes_per_scan(s);
/* how many DMA pages we must fill */
- devpriv->dma_runs_to_end =
- bytes / devpriv->dmabytestomove[0];
+ devpriv->dma_runs_to_end = bytes / dma0->size;
/* on last dma transfer must be moved */
- devpriv->last_dma_run =
- bytes % devpriv->dmabytestomove[0];
+ devpriv->last_dma_run = bytes % dma0->size;
if (devpriv->dma_runs_to_end == 0)
- devpriv->dmabytestomove[0] =
- devpriv->last_dma_run;
+ dma0->size = devpriv->last_dma_run;
devpriv->dma_runs_to_end--;
}
}
- if (devpriv->dmabytestomove[0] > devpriv->hwdmasize) {
- devpriv->dmabytestomove[0] = devpriv->hwdmasize;
+ if (dma0->size > devpriv->hwdmasize) {
+ dma0->size = devpriv->hwdmasize;
devpriv->ai_eos = 0;
}
- if (devpriv->dmabytestomove[1] > devpriv->hwdmasize) {
- devpriv->dmabytestomove[1] = devpriv->hwdmasize;
+ if (dma1->size > devpriv->hwdmasize) {
+ dma1->size = devpriv->hwdmasize;
devpriv->ai_eos = 0;
}
- devpriv->next_dma_buf = 0;
+ devpriv->cur_dma = 0;
set_dma_mode(devpriv->dma, DMA_MODE_READ);
dma_flags = claim_dma_lock();
clear_dma_ff(devpriv->dma);
- set_dma_addr(devpriv->dma, devpriv->hwdmaptr[0]);
- set_dma_count(devpriv->dma, devpriv->dmabytestomove[0]);
+ set_dma_addr(devpriv->dma, dma0->hw_addr);
+ set_dma_count(devpriv->dma, dma0->size);
release_dma_lock(dma_flags);
enable_dma(devpriv->dma);
}
@@ -608,21 +609,20 @@ static void pcl812_ai_setup_next_dma(struct comedi_device
*dev,
struct comedi_subdevice *s)
{
struct pcl812_private *devpriv = dev->private;
+ struct pcl812_dma_desc *dma;
unsigned long dma_flags;
- devpriv->next_dma_buf = 1 - devpriv->next_dma_buf;
+ devpriv->cur_dma = 1 - devpriv->cur_dma;
+ dma = &devpriv->dma_desc[devpriv->cur_dma];
disable_dma(devpriv->dma);
set_dma_mode(devpriv->dma, DMA_MODE_READ);
dma_flags = claim_dma_lock();
- set_dma_addr(devpriv->dma, devpriv->hwdmaptr[devpriv->next_dma_buf]);
+ set_dma_addr(devpriv->dma, dma->hw_addr);
if (devpriv->ai_eos) {
- set_dma_count(devpriv->dma,
- devpriv->dmabytestomove[devpriv->next_dma_buf]);
+ set_dma_count(devpriv->dma, dma->size);
} else {
if (devpriv->dma_runs_to_end) {
- set_dma_count(devpriv->dma,
- devpriv->dmabytestomove[devpriv->
- next_dma_buf]);
+ set_dma_count(devpriv->dma, dma->size);
} else {
set_dma_count(devpriv->dma, devpriv->last_dma_run);
}
@@ -895,19 +895,17 @@ static void pcl812_handle_dma(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct pcl812_private *devpriv = dev->private;
- int len, bufptr;
- unsigned short *ptr;
-
- ptr = (unsigned short *)devpriv->dmabuf[devpriv->next_dma_buf];
- len = (devpriv->dmabytestomove[devpriv->next_dma_buf] >> 1) -
- devpriv->ai_poll_ptr;
+ struct pcl812_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];
+ unsigned int nsamples;
+ int bufptr;
pcl812_ai_setup_next_dma(dev, s);
+ nsamples = comedi_bytes_to_samples(s, dma->size) - devpriv->ai_poll_ptr;
bufptr = devpriv->ai_poll_ptr;
devpriv->ai_poll_ptr = 0;
- transfer_from_dma_buf(dev, s, ptr, bufptr, len);
+ transfer_from_dma_buf(dev, s, (void *)dma->virt_addr, bufptr, nsamples);
}
static irqreturn_t pcl812_interrupt(int irq, void *d)
@@ -935,6 +933,7 @@ static irqreturn_t pcl812_interrupt(int irq, void *d)
static int pcl812_ai_poll(struct comedi_device *dev, struct comedi_subdevice
*s)
{
struct pcl812_private *devpriv = dev->private;
+ struct pcl812_dma_desc *dma;
unsigned long flags;
unsigned int top1, top2, i;
@@ -956,7 +955,8 @@ static int pcl812_ai_poll(struct comedi_device *dev, struct
comedi_subdevice *s)
return 0;
}
/* where is now DMA in buffer */
- top1 = devpriv->dmabytestomove[1 - devpriv->next_dma_buf] - top1;
+ dma = &devpriv->dma_desc[1 - devpriv->cur_dma];
+ top1 = dma->size - top1;
top1 >>= 1; /* sample position */
top2 = top1 - devpriv->ai_poll_ptr;
if (top2 < 1) { /* no new samples */
@@ -964,9 +964,7 @@ static int pcl812_ai_poll(struct comedi_device *dev, struct
comedi_subdevice *s)
return 0;
}
- transfer_from_dma_buf(dev, s,
- (void *)devpriv->dmabuf[1 -
- devpriv->next_dma_buf],
+ transfer_from_dma_buf(dev, s, (void *)dma->virt_addr,
devpriv->ai_poll_ptr, top2);
devpriv->ai_poll_ptr = top1; /* new buffer position */
@@ -1195,6 +1193,7 @@ static void pcl812_set_ai_range_table(struct
comedi_device *dev,
static int pcl812_alloc_dma(struct comedi_device *dev, unsigned int dma_chan)
{
struct pcl812_private *devpriv = dev->private;
+ struct pcl812_dma_desc *dma;
int i;
if (!(dma_chan == 3 || dma_chan == 1))
@@ -1208,14 +1207,13 @@ static int pcl812_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->virt_addr = __get_dma_pages(GFP_KERNEL,
devpriv->dmapages);
+ if (!dma->virt_addr)
return -ENOMEM;
- devpriv->dmabuf[i] = dmabuf;
- devpriv->hwdmaptr[i] = virt_to_bus((void *)dmabuf);
+ dma->hw_addr = virt_to_bus((void *)dma->virt_addr);
}
return 0;
}
@@ -1223,14 +1221,16 @@ static int pcl812_alloc_dma(struct comedi_device *dev,
unsigned int dma_chan)
static void pcl812_free_dma(struct comedi_device *dev)
{
struct pcl812_private *devpriv = dev->private;
+ struct pcl812_dma_desc *dma;
int i;
if (!devpriv)
return;
for (i = 0; i < 2; i++) {
- if (devpriv->dmabuf[i])
- free_pages(devpriv->dmabuf[i], devpriv->dmapages);
+ dma = &devpriv->dma_desc[i];
+ if (dma->virt_addr)
+ free_pages(dma->virt_addr, devpriv->dmapages);
}
if (devpriv->dma)
free_dma(devpriv->dma);
--
2.0.3
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