From: H Hartley Sweeten <hsweeten@visionengravers.com>
Date: Mon, 17 Feb 2014 21:26:50 +0000 (-0700)
Subject: staging: comedi: pcl818: clarify dma channel request in pcl818_attach()
X-Git-Tag: firefly_0821_release~176^2~4193^2~988
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4ba4a2d307de7b60b47506346ad5e2bdf37e211a;p=firefly-linux-kernel-4.4.55.git
staging: comedi: pcl818: clarify dma channel request in pcl818_attach()
All the board types that can do DMA can use DMA channels 3 or 1. Remove
the 'DMAbits', which is a mask of the valid channels, from the boardinfo
and replace it with a bit-field flag 'has_dma'.
Refactor pcl818_attach() to use the new flag and 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>
---
diff --git a/drivers/staging/comedi/drivers/pcl818.c b/drivers/staging/comedi/drivers/pcl818.c
index a000f742b0bf..9cb3e460c915 100644
--- a/drivers/staging/comedi/drivers/pcl818.c
+++ b/drivers/staging/comedi/drivers/pcl818.c
@@ -267,9 +267,9 @@ struct pcl818_board {
int n_dochan;
const struct comedi_lrange *ai_range_type;
unsigned int IRQbits;
- unsigned int DMAbits;
int ai_maxdata;
int ao_maxdata;
+ unsigned int has_dma:1;
unsigned int has_fifo:1;
int is_818;
};
@@ -286,9 +286,9 @@ static const struct pcl818_board boardtypes[] = {
.n_dochan = 16,
.ai_range_type = &range_pcl818l_l_ai,
.IRQbits = 0x00fc,
- .DMAbits = 0x0a,
.ai_maxdata = 0xfff,
.ao_maxdata = 0xfff,
+ .has_dma = 1,
.is_818 = 1,
}, {
.name = "pcl818h",
@@ -301,9 +301,9 @@ static const struct pcl818_board boardtypes[] = {
.n_dochan = 16,
.ai_range_type = &range_pcl818h_ai,
.IRQbits = 0x00fc,
- .DMAbits = 0x0a,
.ai_maxdata = 0xfff,
.ao_maxdata = 0xfff,
+ .has_dma = 1,
.is_818 = 1,
}, {
.name = "pcl818hd",
@@ -316,9 +316,9 @@ static const struct pcl818_board boardtypes[] = {
.n_dochan = 16,
.ai_range_type = &range_pcl818h_ai,
.IRQbits = 0x00fc,
- .DMAbits = 0x0a,
.ai_maxdata = 0xfff,
.ao_maxdata = 0xfff,
+ .has_dma = 1,
.has_fifo = 1,
.is_818 = 1,
}, {
@@ -332,9 +332,9 @@ static const struct pcl818_board boardtypes[] = {
.n_dochan = 16,
.ai_range_type = &range_pcl818hg_ai,
.IRQbits = 0x00fc,
- .DMAbits = 0x0a,
.ai_maxdata = 0xfff,
.ao_maxdata = 0xfff,
+ .has_dma = 1,
.has_fifo = 1,
.is_818 = 1,
}, {
@@ -348,9 +348,9 @@ static const struct pcl818_board boardtypes[] = {
.n_dochan = 16,
.ai_range_type = &range_pcl818h_ai,
.IRQbits = 0x00fc,
- .DMAbits = 0x0a,
.ai_maxdata = 0xfff,
.ao_maxdata = 0xfff,
+ .has_dma = 1,
.is_818 = 1,
}, {
.name = "pcl718",
@@ -363,9 +363,9 @@ static const struct pcl818_board boardtypes[] = {
.n_dochan = 16,
.ai_range_type = &range_unipolar5,
.IRQbits = 0x00fc,
- .DMAbits = 0x0a,
.ai_maxdata = 0xfff,
.ao_maxdata = 0xfff,
+ .has_dma = 1,
}, {
.name = "pcm3718",
.n_ranges = 9,
@@ -376,9 +376,9 @@ static const struct pcl818_board boardtypes[] = {
.n_dochan = 16,
.ai_range_type = &range_pcl818h_ai,
.IRQbits = 0x00fc,
- .DMAbits = 0x0a,
.ai_maxdata = 0xfff,
.ao_maxdata = 0xfff,
+ .has_dma = 1,
.is_818 = 1,
},
};
@@ -1315,7 +1315,6 @@ static int pcl818_attach(struct comedi_device *dev, struct comedi_devconfig *it)
const struct pcl818_board *board = comedi_board(dev);
struct pcl818_private *devpriv;
int ret;
- int dma;
unsigned long pages;
struct comedi_subdevice *s;
@@ -1347,24 +1346,18 @@ static int pcl818_attach(struct comedi_device *dev, struct comedi_devconfig *it)
devpriv->irq_blocked = 0; /* number of subdevice which use IRQ */
devpriv->ai_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) {
+ /* we need an IRQ to do DMA on channel 3 or 1 */
+ if (dev->irq && board->has_dma &&
+ (it->options[2] == 3 || it->options[2] == 1)) {
+ ret = request_dma(it->options[2], dev->board_name);
+ if (ret) {
dev_err(dev->class_dev,
- "DMA is out of allowed range, FAIL!\n");
- return -EINVAL; /* Bad DMA */
+ "unable to request DMA channel %d\n",
+ it->options[2]);
+ return -EBUSY;
}
- ret = request_dma(dma, dev->board_name);
- if (ret)
- return -EBUSY; /* DMA isn't free */
- devpriv->dma = dma;
+ devpriv->dma = it->options[2];
+
pages = 2; /* we need 16KB */
devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages);
if (!devpriv->dmabuf[0])
@@ -1381,8 +1374,6 @@ static int pcl818_attach(struct comedi_device *dev, struct comedi_devconfig *it)
devpriv->hwdmasize[1] = (1 << pages) * PAGE_SIZE;
}
-no_dma:
-
ret = comedi_alloc_subdevices(dev, 4);
if (ret)
return ret;