staging: comedi: dt9812: use CR_CHAN() for channel number

As pointed out by Dan Carpenper in
<http://driverdev.linuxdriverproject.org/pipermail/devel/2013-February/036025.html>,
the dt9812 comedi driver's use of the `chanspec` member of `struct
comedi_insn` as a channel number is incorrect.  Change it to use
`CR_CHAN(insn->chanspec)` as the channel number (where `insn` is a
pointer to the `struct comedi_insn` being processed).

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org> # 3.8 onwards
Cc: Anders Blomdell <anders.blomdell@control.lth.se>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 6 deletions

diff --git a/drivers/staging/comedi/drivers/dt9812.c b/drivers/staging/comedi/drivers/dt9812.c
index 192cf088f834..57b451904791 100644
--- a/drivers/staging/comedi/drivers/dt9812.c
+++ b/drivers/staging/comedi/drivers/dt9812.c
@@ -947,12 +947,13 @@ static int dt9812_di_rinsn(struct comedi_device *dev,
                            unsigned int *data)
 {
         struct comedi_dt9812 *devpriv = dev->private;
+        unsigned int channel = CR_CHAN(insn->chanspec);
         int n;
         u8 bits = 0;
 
         dt9812_digital_in(devpriv->slot, &bits);
         for (n = 0; n < insn->n; n++)
-                data[n] = ((1 << insn->chanspec) & bits) != 0;
+                data[n] = ((1 << channel) & bits) != 0;
         return n;
 }
 
@@ -961,12 +962,13 @@ static int dt9812_do_winsn(struct comedi_device *dev,
                            unsigned int *data)
 {
         struct comedi_dt9812 *devpriv = dev->private;
+        unsigned int channel = CR_CHAN(insn->chanspec);
         int n;
         u8 bits = 0;
 
         dt9812_digital_out_shadow(devpriv->slot, &bits);
         for (n = 0; n < insn->n; n++) {
-                u8 mask = 1 << insn->chanspec;
+                u8 mask = 1 << channel;
 
                 bits &= ~mask;
                 if (data[n])
@@ -981,13 +983,13 @@ static int dt9812_ai_rinsn(struct comedi_device *dev,
                            unsigned int *data)
 {
         struct comedi_dt9812 *devpriv = dev->private;
+        unsigned int channel = CR_CHAN(insn->chanspec);
         int n;
 
         for (n = 0; n < insn->n; n++) {
                 u16 value = 0;
 
-                dt9812_analog_in(devpriv->slot, insn->chanspec, &value,
-                                 DT9812_GAIN_1);
+                dt9812_analog_in(devpriv->slot, channel, &value, DT9812_GAIN_1);
                 data[n] = value;
         }
         return n;
@@ -998,12 +1000,13 @@ static int dt9812_ao_rinsn(struct comedi_device *dev,
                            unsigned int *data)
 {
         struct comedi_dt9812 *devpriv = dev->private;
+        unsigned int channel = CR_CHAN(insn->chanspec);
         int n;
         u16 value;
 
         for (n = 0; n < insn->n; n++) {
                 value = 0;
-                dt9812_analog_out_shadow(devpriv->slot, insn->chanspec, &value);
+                dt9812_analog_out_shadow(devpriv->slot, channel, &value);
                 data[n] = value;
         }
         return n;
@@ -1014,10 +1017,11 @@ static int dt9812_ao_winsn(struct comedi_device *dev,
                            unsigned int *data)
 {
         struct comedi_dt9812 *devpriv = dev->private;
+        unsigned int channel = CR_CHAN(insn->chanspec);
         int n;
 
         for (n = 0; n < insn->n; n++)
-                dt9812_analog_out(devpriv->slot, insn->chanspec, data[n]);
+                dt9812_analog_out(devpriv->slot, channel, data[n]);
         return n;
 }