Use the comedi_timeout() helper to wait for the DAC to be idle before
writing to it.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/adv_pci1724.c | 33 +++++++++++-----------------
1 file changed, 13 insertions(+), 20 deletions(-)
diff --git a/drivers/staging/comedi/drivers/adv_pci1724.c b/drivers/staging/comedi/drivers/adv_pci1724.c
index cc70ed8..c19d359 100644
--- a/drivers/staging/comedi/drivers/adv_pci1724.c
+++ b/drivers/staging/comedi/drivers/adv_pci1724.c
@@ -53,7 +53,6 @@ supported PCI devices are configured as comedi devices automatically.
*/
#include <linux/module.h>
-#include <linux/delay.h>
#include <linux/pci.h>
#include "../comedidev.h"
@@ -123,34 +122,24 @@ static const struct comedi_lrange ao_ranges_1724 = {
}
};
-static int wait_for_dac_idle(struct comedi_device *dev)
+static int adv_pci1724_dac_idle(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_insn *insn,
+ unsigned long context)
{
- static const int timeout = 10000;
- int i;
+ unsigned int status;
- for (i = 0; i < timeout; ++i) {
- if ((inl(dev->iobase + SYNC_OUTPUT_REG) & DAC_BUSY) == 0)
- break;
- udelay(1);
- }
- if (i == timeout) {
- dev_err(dev->class_dev,
- "Timed out waiting for dac to become idle\n");
- return -EIO;
- }
- return 0;
+ status = inl(dev->iobase + SYNC_OUTPUT_REG);
+ if ((status & DAC_BUSY) == 0)
+ return 0;
+ return -EBUSY;
}
static int set_dac(struct comedi_device *dev, unsigned mode, unsigned channel,
unsigned data)
{
- int retval;
unsigned control_bits;
- retval = wait_for_dac_idle(dev);
- if (retval < 0)
- return retval;
-
control_bits = mode;
control_bits |= dac_channel_and_group_select_bits(channel);
control_bits |= dac_data_bits(data);
@@ -174,6 +163,10 @@ static int adv_pci1724_insn_write(struct comedi_device *dev,
for (i = 0; i < insn->n; ++i) {
unsigned int val = data[i];
+ ret = comedi_timeout(dev, s, insn, adv_pci1724_dac_idle, 0);
+ if (ret)
+ return ret;
+
ret = set_dac(dev, mode, chan, val);
if (ret < 0)
return ret;
--
2.0.3
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