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/dt282x.c | 111 +++++++++++++++-----------------
1 file changed, 53 insertions(+), 58 deletions(-)
diff --git a/drivers/staging/comedi/drivers/dt282x.c b/drivers/staging/comedi/drivers/dt282x.c
index 873aae6..8ee6186 100644
--- a/drivers/staging/comedi/drivers/dt282x.c
+++ b/drivers/staging/comedi/drivers/dt282x.c
@@ -300,6 +300,12 @@ static const struct dt282x_board boardtypes[] = {
},
};
+struct dt282x_dma_desc {
+ unsigned int chan; /* DMA channel */
+ unsigned short *virt_addr; /* virtual address of DMA buffer */
+ unsigned int size; /* transfer size (in bytes) */
+};
+
struct dt282x_private {
unsigned int ad_2scomp:1;
@@ -312,21 +318,16 @@ struct dt282x_private {
int ntrig;
int nread;
- struct {
- int chan;
- unsigned short *buf; /* DMA buffer */
- int size; /* size of current transfer */
- } dma[2];
+ struct dt282x_dma_desc dma_desc[2];
int dma_maxsize; /* max size of DMA transfer (in bytes) */
- int current_dma_index;
+ int cur_dma;
int dma_dir;
};
static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n)
{
struct dt282x_private *devpriv = dev->private;
- int dma_chan;
- unsigned long dma_ptr;
+ struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index];
unsigned long flags;
if (!devpriv->ntrig)
@@ -338,18 +339,16 @@ static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n)
n = devpriv->ntrig * 2;
devpriv->ntrig -= n / 2;
- devpriv->dma[dma_index].size = n;
- dma_chan = devpriv->dma[dma_index].chan;
- dma_ptr = virt_to_bus(devpriv->dma[dma_index].buf);
+ dma->size = n;
- set_dma_mode(dma_chan, DMA_MODE_READ);
+ set_dma_mode(dma->chan, DMA_MODE_READ);
flags = claim_dma_lock();
- clear_dma_ff(dma_chan);
- set_dma_addr(dma_chan, dma_ptr);
- set_dma_count(dma_chan, n);
+ clear_dma_ff(dma->chan);
+ set_dma_addr(dma->chan, virt_to_bus(dma->virt_addr));
+ set_dma_count(dma->chan, dma->size);
release_dma_lock(flags);
- enable_dma(dma_chan);
+ enable_dma(dma->chan);
return n;
}
@@ -357,22 +356,19 @@ static int dt282x_prep_ai_dma(struct comedi_device *dev, int dma_index, int n)
static int dt282x_prep_ao_dma(struct comedi_device *dev, int dma_index, int n)
{
struct dt282x_private *devpriv = dev->private;
- int dma_chan;
- unsigned long dma_ptr;
+ struct dt282x_dma_desc *dma = &devpriv->dma_desc[dma_index];
unsigned long flags;
- devpriv->dma[dma_index].size = n;
- dma_chan = devpriv->dma[dma_index].chan;
- dma_ptr = virt_to_bus(devpriv->dma[dma_index].buf);
+ dma->size = n;
- set_dma_mode(dma_chan, DMA_MODE_WRITE);
+ set_dma_mode(dma->chan, DMA_MODE_WRITE);
flags = claim_dma_lock();
- clear_dma_ff(dma_chan);
- set_dma_addr(dma_chan, dma_ptr);
- set_dma_count(dma_chan, n);
+ clear_dma_ff(dma->chan);
+ set_dma_addr(dma->chan, virt_to_bus(dma->virt_addr));
+ set_dma_count(dma->chan, dma->size);
release_dma_lock(flags);
- enable_dma(dma_chan);
+ enable_dma(dma->chan);
return n;
}
@@ -381,8 +377,8 @@ static void dt282x_disable_dma(struct comedi_device *dev)
{
struct dt282x_private *devpriv = dev->private;
- disable_dma(devpriv->dma[0].chan);
- disable_dma(devpriv->dma[1].chan);
+ disable_dma(devpriv->dma_desc[0].chan);
+ disable_dma(devpriv->dma_desc[1].chan);
}
static unsigned int dt282x_ns_to_timer(unsigned int *ns, unsigned int flags)
@@ -444,11 +440,11 @@ static unsigned int dt282x_ao_setup_dma(struct comedi_device *dev,
int cur_dma)
{
struct dt282x_private *devpriv = dev->private;
- void *ptr = devpriv->dma[cur_dma].buf;
+ struct dt282x_dma_desc *dma = &devpriv->dma_desc[cur_dma];
unsigned int nsamples = comedi_bytes_to_samples(s, devpriv->dma_maxsize);
unsigned int nbytes;
- nbytes = comedi_buf_read_samples(s, ptr, nsamples);
+ nbytes = comedi_buf_read_samples(s, dma->virt_addr, nsamples);
if (nbytes)
dt282x_prep_ao_dma(dev, cur_dma, nbytes);
else
@@ -461,39 +457,35 @@ static void dt282x_ao_dma_interrupt(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct dt282x_private *devpriv = dev->private;
- int cur_dma = devpriv->current_dma_index;
+ struct dt282x_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];
outw(devpriv->supcsr | DT2821_SUPCSR_CLRDMADNE,
dev->iobase + DT2821_SUPCSR_REG);
- disable_dma(devpriv->dma[cur_dma].chan);
+ disable_dma(dma->chan);
- devpriv->current_dma_index = 1 - cur_dma;
-
- if (!dt282x_ao_setup_dma(dev, s, cur_dma))
+ if (!dt282x_ao_setup_dma(dev, s, devpriv->cur_dma))
s->async->events |= COMEDI_CB_OVERFLOW;
+
+ devpriv->cur_dma = 1 - devpriv->cur_dma;
}
static void dt282x_ai_dma_interrupt(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct dt282x_private *devpriv = dev->private;
- int cur_dma = devpriv->current_dma_index;
- void *ptr = devpriv->dma[cur_dma].buf;
- int size = devpriv->dma[cur_dma].size;
- unsigned int nsamples = comedi_bytes_to_samples(s, size);
+ struct dt282x_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];
+ unsigned int nsamples = comedi_bytes_to_samples(s, dma->size);
int ret;
outw(devpriv->supcsr | DT2821_SUPCSR_CLRDMADNE,
dev->iobase + DT2821_SUPCSR_REG);
- disable_dma(devpriv->dma[cur_dma].chan);
+ disable_dma(dma->chan);
- devpriv->current_dma_index = 1 - cur_dma;
-
- dt282x_munge(dev, s, ptr, size);
- ret = comedi_buf_write_samples(s, ptr, nsamples);
- if (ret != size)
+ dt282x_munge(dev, s, dma->virt_addr, dma->size);
+ ret = comedi_buf_write_samples(s, dma->virt_addr, nsamples);
+ if (ret != dma->size)
return;
devpriv->nread -= nsamples;
@@ -514,7 +506,9 @@ static void dt282x_ai_dma_interrupt(struct comedi_device *dev,
}
#endif
/* restart the channel */
- dt282x_prep_ai_dma(dev, cur_dma, 0);
+ dt282x_prep_ai_dma(dev, devpriv->cur_dma, 0);
+
+ devpriv->cur_dma = 1 - devpriv->cur_dma;
}
static irqreturn_t dt282x_interrupt(int irq, void *d)
@@ -769,7 +763,7 @@ static int dt282x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
devpriv->nread = devpriv->ntrig;
devpriv->dma_dir = DMA_MODE_READ;
- devpriv->current_dma_index = 0;
+ devpriv->cur_dma = 0;
dt282x_prep_ai_dma(dev, 0, 0);
if (devpriv->ntrig) {
dt282x_prep_ai_dma(dev, 1, 0);
@@ -949,7 +943,7 @@ static int dt282x_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
devpriv->nread = devpriv->ntrig;
devpriv->dma_dir = DMA_MODE_WRITE;
- devpriv->current_dma_index = 0;
+ devpriv->cur_dma = 0;
outw(devpriv->divisor, dev->iobase + DT2821_TMRCTR_REG);
@@ -1090,10 +1084,11 @@ static int dt282x_alloc_dma(struct comedi_device *dev,
devpriv->dma_maxsize = PAGE_SIZE;
for (i = 0; i < 2; i++) {
- devpriv->dma[i].chan = dma_chan[i];
- devpriv->dma[i].buf =
- (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
- if (!devpriv->dma[i].buf)
+ struct dt282x_dma_desc *dma = &devpriv->dma_desc[i];
+
+ dma->chan = dma_chan[i];
+ dma->virt_addr = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
+ if (!dma->virt_addr)
return -ENOMEM;
}
@@ -1103,18 +1098,18 @@ static int dt282x_alloc_dma(struct comedi_device *dev,
static void dt282x_free_dma(struct comedi_device *dev)
{
struct dt282x_private *devpriv = dev->private;
+ struct dt282x_dma_desc *dma;
int i;
if (!devpriv)
return;
for (i = 0; i < 2; i++) {
- if (devpriv->dma[i].chan)
- free_dma(devpriv->dma[i].chan);
- if (devpriv->dma[i].buf)
- free_page((unsigned long)devpriv->dma[i].buf);
- devpriv->dma[i].chan = 0;
- devpriv->dma[i].buf = NULL;
+ dma = &devpriv->dma_desc[i];
+ if (dma->chan)
+ free_dma(dma->chan);
+ if (dma->virt_addr)
+ free_page((unsigned long)dma->virt_addr);
}
}
--
2.0.3
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