The comedi (*insn_read) functions are supposed to do simple one-shot
reading of an analog input channel. Currently this driver enables
interrupts and uses wait_for_completion_interruptible() to allow the
interrupt routine to let the analog input (*insn_read) know that
the end-of-conversion has occured.
Simplify the function by using the comedi_timeout() helper to check
the aux status register to see when the conversion is finished.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/quatech_daqp_cs.c | 57 ++++++++++++------------
1 file changed, 28 insertions(+), 29 deletions(-)
diff --git a/drivers/staging/comedi/drivers/quatech_daqp_cs.c b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
index 17b614c..8237826 100644
--- a/drivers/staging/comedi/drivers/quatech_daqp_cs.c
+++ b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
@@ -40,8 +40,6 @@
*/
#include <linux/module.h>
-#include <linux/semaphore.h>
-#include <linux/completion.h>
#include "../comedi_pcmcia.h"
@@ -147,8 +145,6 @@ struct daqp_private {
int stop;
enum { semaphore, buffer } interrupt_mode;
-
- struct completion eos;
};
static const struct comedi_lrange range_daqp_ai = {
@@ -210,15 +206,6 @@ static unsigned int daqp_ai_get_sample(struct comedi_device *dev,
return comedi_offset_munge(s, val);
}
-/* Interrupt handler
- *
- * Operates in one of two modes. If devpriv->interrupt_mode is
- * 'semaphore', just signal the devpriv->eos completion and return
- * (one-shot mode). Otherwise (continuous mode), read data in from
- * the card, transfer it to the buffer provided by the higher-level
- * comedi kernel module, and signal various comedi callback routines,
- * which run pretty quick.
- */
static enum irqreturn daqp_interrupt(int irq, void *dev_id)
{
struct comedi_device *dev = dev_id;
@@ -233,7 +220,6 @@ static enum irqreturn daqp_interrupt(int irq, void *dev_id)
switch (devpriv->interrupt_mode) {
case semaphore:
- complete(&devpriv->eos);
break;
case buffer:
@@ -296,14 +282,26 @@ static void daqp_ai_set_one_scanlist_entry(struct comedi_device *dev,
outb((val >> 8) & 0xff, dev->iobase + DAQP_SCANLIST_REG);
}
-/* One-shot analog data acquisition routine */
+static int daqp_ai_eos(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_insn *insn,
+ unsigned long context)
+{
+ unsigned int status;
+
+ status = inb(dev->iobase + DAQP_AUX_REG);
+ if (status & DAQP_AUX_CONVERSION)
+ return 0;
+ return -EBUSY;
+}
static int daqp_ai_insn_read(struct comedi_device *dev,
struct comedi_subdevice *s,
- struct comedi_insn *insn, unsigned int *data)
+ struct comedi_insn *insn,
+ unsigned int *data)
{
struct daqp_private *devpriv = dev->private;
- int ret;
+ int ret = 0;
int i;
if (devpriv->stop)
@@ -321,34 +319,35 @@ static int daqp_ai_insn_read(struct comedi_device *dev,
daqp_ai_set_one_scanlist_entry(dev, insn->chanspec, 1);
/* Reset data FIFO (see page 28 of DAQP User's Manual) */
-
outb(DAQP_CMD_RSTF, dev->iobase + DAQP_CMD_REG);
- /* Set trigger - one-shot, internal */
- outb(DAQP_CTRL_PACER_CLK_100KHZ | DAQP_CTRL_EOS_INT_ENA,
- dev->iobase + DAQP_CTRL_REG);
+ /* Set trigger - one-shot, internal, no interrupts */
+ outb(DAQP_CTRL_PACER_CLK_100KHZ, dev->iobase + DAQP_CTRL_REG);
ret = daqp_clear_events(dev, 10000);
if (ret)
return ret;
- init_completion(&devpriv->eos);
- devpriv->interrupt_mode = semaphore;
-
for (i = 0; i < insn->n; i++) {
/* Start conversion */
outb(DAQP_CMD_ARM | DAQP_CMD_FIFO_DATA,
dev->iobase + DAQP_CMD_REG);
- /* Wait for interrupt service routine to unblock completion */
- /* Maybe could use a timeout here, but it's interruptible */
- if (wait_for_completion_interruptible(&devpriv->eos))
- return -EINTR;
+ ret = comedi_timeout(dev, s, insn, daqp_ai_eos, 0);
+ if (ret)
+ break;
+
+ /* clear the status event flags */
+ inb(dev->iobase + DAQP_STATUS_REG);
data[i] = daqp_ai_get_sample(dev, s);
}
- return insn->n;
+ /* stop any conversions and clear the status event flags */
+ outb(DAQP_CMD_STOP, dev->iobase + DAQP_CMD_REG);
+ inb(dev->iobase + DAQP_STATUS_REG);
+
+ return ret ? ret : insn->n;
}
/* This function converts ns nanoseconds to a counter value suitable
--
2.5.1
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