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staging: comedi: dt282x: IRQ and DMA are needed for async command support

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This driver requires an IRQ and 2 DMA channels in order to execute async
commands.

Modify the (*attach) so that command support is only hooked up if
DMA is available. This allows removing the extra checks in the
command support functions.

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
2014-06-20 13:12:41 -07:00
committed by Greg Kroah-Hartman
parent ebf86ea9a6
commit cb3d0d3996
1 changed files with 52 additions and 60 deletions
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112
drivers/staging/comedi/drivers/dt282x.c
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@@ -343,7 +343,6 @@ struct dt282x_private {
int size; /* size of current transfer */
} dma[2];
int dma_maxsize; /* max size of DMA transfer (in bytes) */
int usedma; /* driver uses DMA */
int current_dma_index;
int dma_dir;
};
@@ -412,10 +411,8 @@ static void dt282x_disable_dma(struct comedi_device *dev)
{
struct dt282x_private *devpriv = dev->private;
if (devpriv->usedma) {
disable_dma(devpriv->dma[0].chan);
disable_dma(devpriv->dma[1].chan);
}
disable_dma(devpriv->dma[0].chan);
disable_dma(devpriv->dma[1].chan);
}
static int dt282x_ns_to_timer(int *nanosec, int round_mode)
@@ -788,13 +785,6 @@ static int dt282x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
int timer;
int ret;
if (devpriv->usedma == 0) {
comedi_error(dev,
"driver requires 2 dma channels"
" to execute command");
return -EIO;
}
dt282x_disable_dma(dev);
if (cmd->convert_arg < board->ai_speed)
@@ -1014,13 +1004,6 @@ static int dt282x_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
int timer;
struct comedi_cmd *cmd = &s->async->cmd;
if (devpriv->usedma == 0) {
comedi_error(dev,
"driver requires 2 dma channels"
" to execute command");
return -EIO;
}
dt282x_disable_dma(dev);
devpriv->supcsr = DT2821_ERRINTEN | DT2821_DS1 | DT2821_DDMA;
@@ -1155,21 +1138,6 @@ static int dt282x_grab_dma(struct comedi_device *dev, int dma1, int dma2)
struct dt282x_private *devpriv = dev->private;
int ret;
devpriv->usedma = 0;
if (!dma1 && !dma2)
return 0;
if (dma1 == dma2 || dma1 < 5 || dma2 < 5 || dma1 > 7 || dma2 > 7)
return -EINVAL;
if (dma2 < dma1) {
int i;
i = dma1;
dma1 = dma2;
dma2 = i;
}
ret = request_dma(dma1, "dt282x A");
if (ret)
return -EBUSY;
@@ -1186,11 +1154,27 @@ static int dt282x_grab_dma(struct comedi_device *dev, int dma1, int dma2)
if (!devpriv->dma[0].buf || !devpriv->dma[1].buf)
return -ENOMEM;
devpriv->usedma = 1;
return 0;
}
static void dt282x_free_dma(struct comedi_device *dev)
{
struct dt282x_private *devpriv = dev->private;
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;
}
}
/*
options:
0 i/o base
@@ -1235,22 +1219,41 @@ static int dt282x_attach(struct comedi_device *dev, struct comedi_devconfig *it)
}
/* should do board test */
if (it->options[opt_irq] > 0) {
ret = request_irq(it->options[opt_irq], dt282x_interrupt, 0,
dev->board_name, dev);
if (ret == 0)
dev->irq = it->options[opt_irq];
}
devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
if (!devpriv)
return -ENOMEM;
if (dev->irq) {
ret = dt282x_grab_dma(dev, it->options[opt_dma1],
it->options[opt_dma2]);
if (ret < 0)
return ret;
/* an IRQ and 2 DMA channels are required for async command support */
if (it->options[opt_irq] &&
it->options[opt_dma1] && it->options[opt_dma2]) {
unsigned int irq = it->options[opt_irq];
unsigned int dma1 = it->options[opt_dma1];
unsigned int dma2 = it->options[opt_dma2];
if (dma2 < dma1) {
unsigned int swap;
swap = dma1;
dma1 = dma2;
dma2 = swap;
}
if (dma1 != dma2 &&
dma1 >= 5 && dma1 <= 7 &&
dma2 >= 5 && dma2 <= 7) {
ret = request_irq(irq, dt282x_interrupt, 0,
dev->board_name, dev);
if (ret == 0) {
dev->irq = irq;
ret = dt282x_grab_dma(dev, dma1, dma2);
if (ret < 0) {
dt282x_free_dma(dev);
free_irq(dev->irq, dev);
dev->irq = 0;
}
}
}
}
ret = comedi_alloc_subdevices(dev, 3);
@@ -1323,18 +1326,7 @@ static int dt282x_attach(struct comedi_device *dev, struct comedi_devconfig *it)
static void dt282x_detach(struct comedi_device *dev)
{
struct dt282x_private *devpriv = dev->private;
if (dev->private) {
if (devpriv->dma[0].chan)
free_dma(devpriv->dma[0].chan);
if (devpriv->dma[1].chan)
free_dma(devpriv->dma[1].chan);
if (devpriv->dma[0].buf)
free_page((unsigned long)devpriv->dma[0].buf);
if (devpriv->dma[1].buf)
free_page((unsigned long)devpriv->dma[1].buf);
}
dt282x_free_dma(dev);
comedi_legacy_detach(dev);
}