staging: comedi: das16: "timer_mode" is always used for DMA
As noted in the driver, a timer is always used by this driver to handle the
DMA due to buggy DMA controllers and the lack of a hardware fifo in some of
the supported boards.
Remove all the non-timer mode specific code.
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/das16.c b/drivers/staging/comedi/drivers/das16.c
index 593ec38..2dd03da 100644
--- a/drivers/staging/comedi/drivers/das16.c
+++ b/drivers/staging/comedi/drivers/das16.c
@@ -387,7 +387,6 @@
struct timer_list timer; /* for timed interrupt */
volatile short timer_running;
- volatile short timer_mode; /* true if using timer mode */
unsigned long extra_iobase;
};
@@ -516,49 +515,6 @@
return 0;
}
-/* utility function that suggests a dma transfer size in bytes */
-static unsigned int das16_suggest_transfer_size(struct comedi_device *dev,
- const struct comedi_cmd *cmd)
-{
- struct das16_private_struct *devpriv = dev->private;
- unsigned int size;
- unsigned int freq;
-
- /* if we are using timer interrupt, we don't care how long it
- * will take to complete transfer since it will be interrupted
- * by timer interrupt */
- if (devpriv->timer_mode)
- return DAS16_DMA_SIZE;
-
- /* otherwise, we are relying on dma terminal count interrupt,
- * so pick a reasonable size */
- if (cmd->convert_src == TRIG_TIMER)
- freq = 1000000000 / cmd->convert_arg;
- else if (cmd->scan_begin_src == TRIG_TIMER)
- freq = (1000000000 / cmd->scan_begin_arg) * cmd->chanlist_len;
- /* return some default value */
- else
- freq = 0xffffffff;
-
- if (cmd->flags & TRIG_WAKE_EOS) {
- size = sample_size * cmd->chanlist_len;
- } else {
- /* make buffer fill in no more than 1/3 second */
- size = (freq / 3) * sample_size;
- }
-
- /* set a minimum and maximum size allowed */
- if (size > DAS16_DMA_SIZE)
- size = DAS16_DMA_SIZE - DAS16_DMA_SIZE % sample_size;
- else if (size < sample_size)
- size = sample_size;
-
- if (cmd->stop_src == TRIG_COUNT && size > devpriv->adc_byte_count)
- size = devpriv->adc_byte_count;
-
- return size;
-}
-
static unsigned int das16_set_pacer(struct comedi_device *dev, unsigned int ns,
int rounding_flags)
{
@@ -585,13 +541,6 @@
unsigned long flags;
int range;
- if (devpriv->dma_chan == 0 || (dev->irq == 0
- && devpriv->timer_mode == 0)) {
- comedi_error(dev,
- "irq (or use of 'timer mode') dma required to "
- "execute comedi_cmd");
- return -1;
- }
if (cmd->flags & TRIG_RT) {
comedi_error(dev, "isa dma transfers cannot be performed with "
"TRIG_RT, aborting");
@@ -648,24 +597,16 @@
devpriv->current_buffer = 0;
set_dma_addr(devpriv->dma_chan,
devpriv->dma_buffer_addr[devpriv->current_buffer]);
- /* set appropriate size of transfer */
- devpriv->dma_transfer_size = das16_suggest_transfer_size(dev, cmd);
+ devpriv->dma_transfer_size = DAS16_DMA_SIZE;
set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
enable_dma(devpriv->dma_chan);
release_dma_lock(flags);
/* set up interrupt */
- if (devpriv->timer_mode) {
- devpriv->timer_running = 1;
- devpriv->timer.expires = jiffies + timer_period();
- add_timer(&devpriv->timer);
- devpriv->control_state &= ~DAS16_INTE;
- } else {
- /* clear interrupt bit */
- outb(0x00, dev->iobase + DAS16_STATUS);
- /* enable interrupts */
- devpriv->control_state |= DAS16_INTE;
- }
+ devpriv->timer_running = 1;
+ devpriv->timer.expires = jiffies + timer_period();
+ add_timer(&devpriv->timer);
+ devpriv->control_state &= ~DAS16_INTE;
devpriv->control_state |= DMA_ENABLE;
devpriv->control_state &= ~PACING_MASK;
if (cmd->convert_src == TRIG_EXT)
@@ -696,7 +637,7 @@
disable_dma(devpriv->dma_chan);
/* disable SW timer */
- if (devpriv->timer_mode && devpriv->timer_running) {
+ if (devpriv->timer_running) {
devpriv->timer_running = 0;
del_timer(&devpriv->timer);
}
@@ -864,7 +805,6 @@
static void das16_interrupt(struct comedi_device *dev)
{
- const struct das16_board *board = comedi_board(dev);
struct das16_private_struct *devpriv = dev->private;
unsigned long dma_flags, spin_flags;
struct comedi_subdevice *s = dev->read_subdev;
@@ -915,21 +855,12 @@
devpriv->current_buffer = (devpriv->current_buffer + 1) % 2;
devpriv->adc_byte_count -= num_bytes;
- /* figure out how many bytes for next transfer */
- if (cmd->stop_src == TRIG_COUNT && devpriv->timer_mode == 0 &&
- devpriv->dma_transfer_size > devpriv->adc_byte_count)
- devpriv->dma_transfer_size = devpriv->adc_byte_count;
-
/* re-enable dma */
if ((async->events & COMEDI_CB_EOA) == 0) {
set_dma_addr(devpriv->dma_chan,
devpriv->dma_buffer_addr[devpriv->current_buffer]);
set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
enable_dma(devpriv->dma_chan);
- /* reenable conversions for das1600 mode, (stupid hardware) */
- if (board->size > 0x400 && devpriv->timer_mode == 0)
- outb(0x00, dev->iobase + DAS1600_CONV);
-
}
release_dma_lock(dma_flags);
@@ -1077,20 +1008,15 @@
int ret;
unsigned int irq;
unsigned int dma_chan;
- int timer_mode;
unsigned long flags;
struct comedi_krange *user_ai_range, *user_ao_range;
#if 0
irq = it->options[1];
- timer_mode = it->options[8];
#endif
/* always use time_mode since using irq can drop samples while
* waiting for dma done interrupt (due to hardware limitations) */
irq = 0;
- timer_mode = 1;
- if (timer_mode)
- irq = 0;
/* check that clock setting is valid */
if (it->options[3]) {
@@ -1214,12 +1140,9 @@
user_ao_range->flags = UNIT_volt;
}
- if (timer_mode) {
- init_timer(&(devpriv->timer));
- devpriv->timer.function = das16_timer_interrupt;
- devpriv->timer.data = (unsigned long)dev;
- }
- devpriv->timer_mode = timer_mode ? 1 : 0;
+ init_timer(&(devpriv->timer));
+ devpriv->timer.function = das16_timer_interrupt;
+ devpriv->timer.data = (unsigned long)dev;
ret = comedi_alloc_subdevices(dev, 5);
if (ret)