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staging: comedi: ni_labpc: introduce struct labpc_dma_desc 

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 10:55:52 -07:00 committed by Greg Kroah-Hartman
parent 6d26275177
commit 4d1c15c08f
3 changed files with 41 additions and 34 deletions
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15
drivers/staging/comedi/drivers/ni_labpc.h
View File

@ -34,6 +34,13 @@ struct labpc_boardinfo {
unsigned is_labpc1200:1; /* has extra regs compared to pc+ */
};
struct labpc_dma_desc {
unsigned int chan; /* DMA channel */
u16 *virt_addr; /* virtual address of DMA buffer */
phys_addr_t hw_addr; /* hardware (bus) address of DMA buffer */
unsigned int size; /* size of DMA transfer (in bytes) */
};
struct labpc_private {
/* number of data points left to be taken */
unsigned long long count;
@ -61,11 +68,9 @@ struct labpc_private {
* conversions
*/
unsigned int divisor_b1;
unsigned int dma_chan; /* dma channel to use */
u16 *dma_buffer; /* buffer ai will dma into */
phys_addr_t dma_addr;
/* transfer size in bytes for current transfer */
unsigned int dma_transfer_size;
struct labpc_dma_desc dma_desc;
/* we are using dma/fifo-half-full/etc. */
enum transfer_type current_transfer;
/*

58
drivers/staging/comedi/drivers/ni_labpc_isadma.c
View File

@ -60,22 +60,23 @@ static unsigned int labpc_suggest_transfer_size(const struct comedi_cmd *cmd)
void labpc_setup_dma(struct comedi_device *dev, struct comedi_subdevice *s)
{
struct labpc_private *devpriv = dev->private;
struct labpc_dma_desc *dma = &devpriv->dma_desc;
struct comedi_cmd *cmd = &s->async->cmd;
unsigned long irq_flags;
irq_flags = claim_dma_lock();
disable_dma(devpriv->dma_chan);
disable_dma(dma->chan);
/* clear flip-flop to make sure 2-byte registers for
* count and address get set correctly */
clear_dma_ff(devpriv->dma_chan);
set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);
clear_dma_ff(dma->chan);
set_dma_addr(dma->chan, dma->hw_addr);
/* set appropriate size of transfer */
devpriv->dma_transfer_size = labpc_suggest_transfer_size(cmd);
dma->size = labpc_suggest_transfer_size(cmd);
if (cmd->stop_src == TRIG_COUNT &&
devpriv->count * sample_size < devpriv->dma_transfer_size)
devpriv->dma_transfer_size = devpriv->count * sample_size;
set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
enable_dma(devpriv->dma_chan);
devpriv->count * sample_size < dma->size)
dma->size = devpriv->count * sample_size;
set_dma_count(dma->chan, dma->size);
enable_dma(dma->chan);
release_dma_lock(irq_flags);
/* set CMD3 bits for caller to enable DMA and interrupt */
devpriv->cmd3 |= (CMD3_DMAEN | CMD3_DMATCINTEN);
@ -85,6 +86,7 @@ EXPORT_SYMBOL_GPL(labpc_setup_dma);
void labpc_drain_dma(struct comedi_device *dev)
{
struct labpc_private *devpriv = dev->private;
struct labpc_dma_desc *dma = &devpriv->dma_desc;
struct comedi_subdevice *s = dev->read_subdev;
struct comedi_async *async = s->async;
struct comedi_cmd *cmd = &async->cmd;
@ -95,18 +97,18 @@ void labpc_drain_dma(struct comedi_device *dev)
status = devpriv->stat1;
flags = claim_dma_lock();
disable_dma(devpriv->dma_chan);
disable_dma(dma->chan);
/* clear flip-flop to make sure 2-byte registers for
* count and address get set correctly */
clear_dma_ff(devpriv->dma_chan);
clear_dma_ff(dma->chan);
/* figure out how many points to read */
max_points = devpriv->dma_transfer_size / sample_size;
max_points = dma->size / sample_size;
/* residue is the number of points left to be done on the dma
* transfer. It should always be zero at this point unless
* the stop_src is set to external triggering.
*/
residue = get_dma_residue(devpriv->dma_chan) / sample_size;
residue = get_dma_residue(dma->chan) / sample_size;
num_points = max_points - residue;
if (cmd->stop_src == TRIG_COUNT && devpriv->count < num_points)
num_points = devpriv->count;
@ -114,21 +116,21 @@ void labpc_drain_dma(struct comedi_device *dev)
/* figure out how many points will be stored next time */
leftover = 0;
if (cmd->stop_src != TRIG_COUNT) {
leftover = devpriv->dma_transfer_size / sample_size;
leftover = dma->size / sample_size;
} else if (devpriv->count > num_points) {
leftover = devpriv->count - num_points;
if (leftover > max_points)
leftover = max_points;
}
comedi_buf_write_samples(s, devpriv->dma_buffer, num_points);
comedi_buf_write_samples(s, dma->virt_addr, num_points);
if (cmd->stop_src == TRIG_COUNT)
devpriv->count -= num_points;
/* set address and count for next transfer */
set_dma_addr(devpriv->dma_chan, devpriv->dma_addr);
set_dma_count(devpriv->dma_chan, leftover * sample_size);
set_dma_addr(dma->chan, dma->hw_addr);
set_dma_count(dma->chan, leftover * sample_size);
release_dma_lock(flags);
}
EXPORT_SYMBOL_GPL(labpc_drain_dma);
@ -136,10 +138,11 @@ EXPORT_SYMBOL_GPL(labpc_drain_dma);
static void handle_isa_dma(struct comedi_device *dev)
{
struct labpc_private *devpriv = dev->private;
struct labpc_dma_desc *dma = &devpriv->dma_desc;
labpc_drain_dma(dev);
enable_dma(devpriv->dma_chan);
enable_dma(dma->chan);
/* clear dma tc interrupt */
devpriv->write_byte(dev, 0x1, DMATC_CLEAR_REG);
@ -163,6 +166,7 @@ EXPORT_SYMBOL_GPL(labpc_handle_dma_status);
int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan)
{
struct labpc_private *devpriv = dev->private;
struct labpc_dma_desc *dma = &devpriv->dma_desc;
void *dma_buffer;
unsigned long dma_flags;
int ret;
@ -180,13 +184,13 @@ int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan)
return ret;
}
devpriv->dma_buffer = dma_buffer;
devpriv->dma_chan = dma_chan;
devpriv->dma_addr = virt_to_bus(devpriv->dma_buffer);
dma->virt_addr = dma_buffer;
dma->chan = dma_chan;
dma->hw_addr = virt_to_bus(dma->virt_addr);
dma_flags = claim_dma_lock();
disable_dma(devpriv->dma_chan);
set_dma_mode(devpriv->dma_chan, DMA_MODE_READ);
disable_dma(dma->chan);
set_dma_mode(dma->chan, DMA_MODE_READ);
release_dma_lock(dma_flags);
return 0;
@ -196,13 +200,11 @@ EXPORT_SYMBOL_GPL(labpc_init_dma_chan);
void labpc_free_dma_chan(struct comedi_device *dev)
{
struct labpc_private *devpriv = dev->private;
struct labpc_dma_desc *dma = &devpriv->dma_desc;
kfree(devpriv->dma_buffer);
devpriv->dma_buffer = NULL;
if (devpriv->dma_chan) {
free_dma(devpriv->dma_chan);
devpriv->dma_chan = 0;
}
kfree(dma->virt_addr);
if (dma->chan)
free_dma(dma->chan);
}
EXPORT_SYMBOL_GPL(labpc_free_dma_chan);

2
drivers/staging/comedi/drivers/ni_labpc_isadma.h
View File

@ -13,7 +13,7 @@ static inline bool labpc_have_dma_chan(struct comedi_device *dev)
{
struct labpc_private *devpriv = dev->private;
return (bool)devpriv->dma_chan;
return (bool)devpriv->dma_desc.chan;
}
int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);