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staging: comedi: das16: "timer_mode" is always used for DMA

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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>
This commit is contained in:
H Hartley Sweeten
2013-07-29 13:48:01 -07:00
committed by Greg Kroah-Hartman
parent 7df6896289
commit 23cdad3360
1 changed files with 9 additions and 86 deletions
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95
drivers/staging/comedi/drivers/das16.c
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@@ -387,7 +387,6 @@ struct das16_private_struct {
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 @@ static int das16_cmd_test(struct comedi_device *dev, struct comedi_subdevice *s,
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 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s)
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 @@ static int das16_cmd_exec(struct comedi_device *dev, struct comedi_subdevice *s)
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 @@ static int das16_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
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 int disable_dma_on_even(struct comedi_device *dev)
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 @@ static void das16_interrupt(struct comedi_device *dev)
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 @@ static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it)
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 @@ static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it)
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)