staging: comedi: adq12b: use comedi_timeout()

Use comedi_timeout() to wait for the analog input end-of-conversion.

This also fixes a possible bug where invalid data is returned if the
conversion did not complete.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/adq12b.c b/drivers/staging/comedi/drivers/adq12b.c
index 3190ef7d285eb19e6fd97edac7c6b05ad9d6fdfb..b4ea37704eaf3831135d1e4d0cd126e4e59bd114 100644 (file)
--- a/drivers/staging/comedi/drivers/adq12b.c
+++ b/drivers/staging/comedi/drivers/adq12b.c
@@ -94,8 +94,6 @@ If you do not specify any options, they will default to
 /* mask of the bit at STINR to check end of conversion */
 #define ADQ12B_EOC     0x20
 
-#define TIMEOUT        20
-
 /* available ranges through the PGA gains */
 static const struct comedi_lrange range_adq12b_ai_bipolar = {
        4, {
@@ -122,19 +120,28 @@ struct adq12b_private {
        int last_range;
 };
 
-/*
- * "instructions" read/write data in "one-shot" or "software-triggered"
- * mode.
- */
+static int adq12b_ai_eoc(struct comedi_device *dev,
+                        struct comedi_subdevice *s,
+                        struct comedi_insn *insn,
+                        unsigned long context)
+{
+       unsigned char status;
+
+       status = inb(dev->iobase + ADQ12B_STINR);
+       if (status & ADQ12B_EOC)
+               return 0;
+       return -EBUSY;
+}
 
 static int adq12b_ai_rinsn(struct comedi_device *dev,
                           struct comedi_subdevice *s, struct comedi_insn *insn,
                           unsigned int *data)
 {
        struct adq12b_private *devpriv = dev->private;
-       int n, i;
+       int n;
        int range, channel;
        unsigned char hi, lo, status;
+       int ret;
 
        /* change channel and range only if it is different from the previous */
        range = CR_RANGE(insn->chanspec);
@@ -151,13 +158,9 @@ static int adq12b_ai_rinsn(struct comedi_device *dev,
        for (n = 0; n < insn->n; n++) {
 
                /* wait for end of conversion */
-               i = 0;
-               do {
-                       /* udelay(1); */
-                       status = inb(dev->iobase + ADQ12B_STINR);
-                       status = status & ADQ12B_EOC;
-               } while (status == 0 && ++i < TIMEOUT);
-               /* } while (++i < 10); */
+               ret = comedi_timeout(dev, s, insn, adq12b_ai_eoc, 0);
+               if (ret)
+                       return ret;
 
                /* read data */
                hi = inb(dev->iobase + ADQ12B_ADHIG);