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staging: comedi: pcl816: clarify dma channel request in pcl816_attach()

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All the board types can do DMA using DMA channels 3 or 1. Remove the 'DMAbits',
which is a mask of the valid channels, from the boardinfo.

Refactor pcl816_attach() to remove the need for the goto.

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
2014-02-17 14:26:49 -07:00
committed by Greg Kroah-Hartman
parent 27f3f4d411
commit ee34785cfd
1 changed files with 7 additions and 26 deletions
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33
drivers/staging/comedi/drivers/pcl816.c
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@@ -100,7 +100,6 @@ struct pcl816_board {
int n_dochan;
const struct comedi_lrange *ai_range_type;
unsigned int IRQbits;
unsigned int DMAbits;
int ai_maxdata;
int ao_maxdata;
int ai_chanlist;
@@ -118,7 +117,6 @@ static const struct pcl816_board boardtypes[] = {
.n_dochan = 16,
.ai_range_type = &range_pcl816,
.IRQbits = 0x00fc,
.DMAbits = 0x0a,
.ai_maxdata = 0xffff,
.ao_maxdata = 0xffff,
.ai_chanlist = 1024,
@@ -133,7 +131,6 @@ static const struct pcl816_board boardtypes[] = {
.n_dochan = 16,
.ai_range_type = &range_pcl816,
.IRQbits = 0x00fc,
.DMAbits = 0x0a,
.ai_maxdata = 0x3fff,
.ao_maxdata = 0x3fff,
.ai_chanlist = 1024,
@@ -866,7 +863,6 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it)
const struct pcl816_board *board = comedi_board(dev);
struct pcl816_private *devpriv;
int ret;
unsigned int dma;
unsigned long pages;
/* int i; */
struct comedi_subdevice *s;
@@ -894,30 +890,17 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it)
devpriv->irq_blocked = 0; /* number of subdevice which use IRQ */
devpriv->int816_mode = 0; /* mode of irq */
/* grab our DMA */
dma = 0;
devpriv->dma = dma;
if (!dev->irq)
goto no_dma; /* if we haven't IRQ, we can't use DMA */
if (board->DMAbits != 0) { /* board support DMA */
dma = it->options[2];
if (dma < 1)
goto no_dma; /* DMA disabled */
if (((1 << dma) & board->DMAbits) == 0) {
dev_err(dev->class_dev,
"DMA is out of allowed range, FAIL!\n");
return -EINVAL; /* Bad DMA */
}
ret = request_dma(dma, dev->board_name);
/* we need an IRQ to do DMA on channel 3 or 1 */
if (dev->irq && (it->options[2] == 3 || it->options[2] == 1)) {
ret = request_dma(it->options[2], dev->board_name);
if (ret) {
dev_err(dev->class_dev,
"unable to allocate DMA %u, FAIL!\n", dma);
return -EBUSY; /* DMA isn't free */
"unable to request DMA channel %d\n",
it->options[2]);
return -EBUSY;
}
devpriv->dma = it->options[2];
devpriv->dma = dma;
pages = 2; /* we need 16KB */
devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages);
@@ -945,8 +928,6 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it)
devpriv->hwdmasize[1] = (1 << pages) * PAGE_SIZE;
}
no_dma:
/* if (board->n_aochan > 0)
subdevs[1] = COMEDI_SUBD_AO;
if (board->n_dichan > 0)