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staging: comedi: pcl816: introduce struct pcl816_dma_desc

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For aesthetics, introduce a struct to hold the DMA descriptor data.

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>
This commit is contained in:
H Hartley Sweeten 2015-01-12 10:56:02 -07:00 committed by Greg Kroah-Hartman
parent d7b8bbb6a7
commit 16d87782c5
1 changed files with 28 additions and 23 deletions
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51
drivers/staging/comedi/drivers/pcl816.c
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@ -113,13 +113,17 @@ static const struct pcl816_board boardtypes[] = {
},
};
struct pcl816_dma_desc {
unsigned long virt_addr; /* virtual address of DMA buffer */
unsigned int hw_addr; /* hardware (bus) address of DMA buffer */
};
struct pcl816_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 pcl816_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 ai_poll_ptr; /* how many sampes transfer poll */
@ -152,6 +156,7 @@ static void pcl816_ai_setup_dma(struct comedi_device *dev,
struct comedi_subdevice *s)
{
struct pcl816_private *devpriv = dev->private;
struct pcl816_dma_desc *dma = &devpriv->dma_desc[0];
struct comedi_cmd *cmd = &s->async->cmd;
unsigned int dma_flags;
unsigned int bytes;
@ -172,11 +177,11 @@ static void pcl816_ai_setup_dma(struct comedi_device *dev,
} else
devpriv->dma_runs_to_end = -1;
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_addr(devpriv->dma, dma->hw_addr);
set_dma_count(devpriv->dma, bytes);
release_dma_lock(dma_flags);
enable_dma(devpriv->dma);
@ -187,16 +192,17 @@ static void pcl816_ai_setup_next_dma(struct comedi_device *dev,
{
struct pcl816_private *devpriv = dev->private;
struct comedi_cmd *cmd = &s->async->cmd;
struct pcl816_dma_desc *dma;
unsigned long dma_flags;
disable_dma(devpriv->dma);
if (devpriv->dma_runs_to_end > -1 || cmd->stop_src == TRIG_NONE) {
/* switch dma bufs */
devpriv->next_dma_buf = 1 - devpriv->next_dma_buf;
devpriv->cur_dma = 1 - devpriv->cur_dma;
dma = &devpriv->dma_desc[devpriv->cur_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->dma_runs_to_end)
set_dma_count(devpriv->dma, devpriv->hwdmasize);
else
@ -318,7 +324,7 @@ static irqreturn_t pcl816_interrupt(int irq, void *d)
struct comedi_device *dev = d;
struct comedi_subdevice *s = dev->read_subdev;
struct pcl816_private *devpriv = dev->private;
unsigned short *ptr;
struct pcl816_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];
unsigned int bufptr;
unsigned int len;
@ -333,15 +339,14 @@ static irqreturn_t pcl816_interrupt(int irq, void *d)
return IRQ_HANDLED;
}
ptr = (unsigned short *)devpriv->dmabuf[devpriv->next_dma_buf];
pcl816_ai_setup_next_dma(dev, s);
len = (devpriv->hwdmasize >> 1) - 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, (unsigned short *)dma->virt_addr,
bufptr, len);
pcl816_ai_clear_eoc(dev);
@ -521,6 +526,7 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
static int pcl816_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)
{
struct pcl816_private *devpriv = dev->private;
struct pcl816_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];
unsigned long flags;
unsigned int top1, top2, i;
@ -546,9 +552,7 @@ static int pcl816_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)
return 0;
}
transfer_from_dma_buf(dev, s,
(unsigned short *)devpriv->dmabuf[devpriv->
next_dma_buf],
transfer_from_dma_buf(dev, s, (unsigned short *)dma->virt_addr,
devpriv->ai_poll_ptr, top2);
devpriv->ai_poll_ptr = top1; /* new buffer position */
@ -661,6 +665,7 @@ static int pcl816_alloc_dma(struct comedi_device *dev,
unsigned int irq_num, unsigned int dma_chan)
{
struct pcl816_private *devpriv = dev->private;
struct pcl816_dma_desc *dma;
int i;
/*
@ -692,14 +697,12 @@ static int pcl816_alloc_dma(struct comedi_device *dev,
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;
}
@ -707,6 +710,7 @@ static int pcl816_alloc_dma(struct comedi_device *dev,
static void pcl816_free_dma(struct comedi_device *dev)
{
struct pcl816_private *devpriv = dev->private;
struct pcl816_dma_desc *dma;
int i;
if (!devpriv)
@ -715,8 +719,9 @@ static void pcl816_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->virt_addr)
free_pages(dma->virt_addr, devpriv->dmapages);
}
}