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staging: comedi: das16: introduce struct das16_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 10:56:12 -07:00 committed by Greg Kroah-Hartman
parent ef98a104c2
commit 38a7d4999a
1 changed files with 26 additions and 22 deletions
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48
drivers/staging/comedi/drivers/das16.c
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@ -439,6 +439,11 @@ static inline int timer_period(void)
return HZ / 20;
}
struct das16_dma_desc {
uint16_t *virt_addr; /* virtual address of DMA buffer */
dma_addr_t hw_addr; /* hardware (bus) address of DMA buffer */
};
struct das16_private_struct {
unsigned int clockbase;
unsigned int ctrl_reg;
@ -446,9 +451,8 @@ struct das16_private_struct {
unsigned int divisor1;
unsigned int divisor2;
unsigned int dma_chan;
uint16_t *dma_buffer[2];
dma_addr_t dma_buffer_addr[2];
unsigned int current_buffer;
struct das16_dma_desc dma_desc[2];
unsigned int cur_dma;
unsigned int dma_transfer_size;
struct comedi_lrange *user_ai_range_table;
struct comedi_lrange *user_ao_range_table;
@ -528,11 +532,12 @@ static void das16_interrupt(struct comedi_device *dev)
struct comedi_subdevice *s = dev->read_subdev;
struct comedi_async *async = s->async;
struct comedi_cmd *cmd = &async->cmd;
struct das16_dma_desc *dma = &devpriv->dma_desc[devpriv->cur_dma];
struct das16_dma_desc *nxt_dma;
unsigned long spin_flags;
unsigned long dma_flags;
unsigned int nsamples;
int num_bytes, residue;
int buffer_index;
spin_lock_irqsave(&dev->spinlock, spin_flags);
if (!(devpriv->ctrl_reg & DAS16_CTRL_DMAE)) {
@ -558,14 +563,13 @@ static void das16_interrupt(struct comedi_device *dev)
async->events |= COMEDI_CB_EOA;
}
buffer_index = devpriv->current_buffer;
devpriv->current_buffer = (devpriv->current_buffer + 1) % 2;
devpriv->cur_dma = 1 - devpriv->cur_dma;
devpriv->adc_byte_count -= num_bytes;
/* re-enable dma */
if ((async->events & COMEDI_CB_EOA) == 0) {
set_dma_addr(devpriv->dma_chan,
devpriv->dma_buffer_addr[devpriv->current_buffer]);
nxt_dma = &devpriv->dma_desc[devpriv->cur_dma];
set_dma_addr(devpriv->dma_chan, nxt_dma->hw_addr);
set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
enable_dma(devpriv->dma_chan);
}
@ -574,8 +578,7 @@ static void das16_interrupt(struct comedi_device *dev)
spin_unlock_irqrestore(&dev->spinlock, spin_flags);
nsamples = comedi_bytes_to_samples(s, num_bytes);
comedi_buf_write_samples(s, devpriv->dma_buffer[buffer_index],
nsamples);
comedi_buf_write_samples(s, dma->virt_addr, nsamples);
comedi_handle_events(dev, s);
}
@ -746,6 +749,7 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s)
{
const struct das16_board *board = dev->board_ptr;
struct das16_private_struct *devpriv = dev->private;
struct das16_dma_desc *dma = &devpriv->dma_desc[0];
struct comedi_async *async = s->async;
struct comedi_cmd *cmd = &async->cmd;
unsigned int byte;
@ -800,9 +804,8 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s)
/* clear flip-flop to make sure 2-byte registers for
* count and address get set correctly */
clear_dma_ff(devpriv->dma_chan);
devpriv->current_buffer = 0;
set_dma_addr(devpriv->dma_chan,
devpriv->dma_buffer_addr[devpriv->current_buffer]);
devpriv->cur_dma = 0;
set_dma_addr(devpriv->dma_chan, dma->hw_addr);
devpriv->dma_transfer_size = DAS16_DMA_SIZE;
set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
enable_dma(devpriv->dma_chan);
@ -1067,13 +1070,13 @@ static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it)
/* allocate dma buffers */
for (i = 0; i < 2; i++) {
void *p;
struct das16_dma_desc *dma = &devpriv->dma_desc[i];
p = pci_alloc_consistent(NULL, DAS16_DMA_SIZE,
&devpriv->dma_buffer_addr[i]);
if (!p)
dma->virt_addr = pci_alloc_consistent(NULL,
DAS16_DMA_SIZE,
&dma->hw_addr);
if (!dma->virt_addr)
return -ENOMEM;
devpriv->dma_buffer[i] = p;
}
flags = claim_dma_lock();
@ -1219,6 +1222,7 @@ static void das16_detach(struct comedi_device *dev)
{
const struct das16_board *board = dev->board_ptr;
struct das16_private_struct *devpriv = dev->private;
struct das16_dma_desc *dma;
int i;
if (devpriv) {
@ -1228,11 +1232,11 @@ static void das16_detach(struct comedi_device *dev)
das16_reset(dev);
for (i = 0; i < 2; i++) {
if (devpriv->dma_buffer[i])
dma = &devpriv->dma_desc[i];
if (dma->virt_addr)
pci_free_consistent(NULL, DAS16_DMA_SIZE,
devpriv->dma_buffer[i],
devpriv->
dma_buffer_addr[i]);
dma->virt_addr,
dma->hw_addr);
}
if (devpriv->dma_chan)
free_dma(devpriv->dma_chan);