staging: comedi: das1800: factor out chanlist checking from (*do_cmdtest)

Step 5 of the (*do_cmdtest) validates that the cmd->chanlist is compatible
with the hardware.

For aesthetics, factor out the step 5 code for the analog input async command
support. Tidy up the factored out code.

To minimize the noise, change the comedi_error(), which is a wrapper around
dev_err(), to dev_dbg().

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>

diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c
index 8e975d6b06db175fe3dff11b3caab1f61e828084..d581029146cb3de06d19b24ba12f3cc6ba49568e 100644 (file)
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -757,6 +757,26 @@ static unsigned int burst_convert_arg(unsigned int convert_arg, int round_mode)
        return micro_sec * 1000;
 }
 
+static int das1800_ai_check_chanlist(struct comedi_device *dev,
+                                    struct comedi_subdevice *s,
+                                    struct comedi_cmd *cmd)
+{
+       unsigned int unipolar0 = CR_RANGE(cmd->chanlist[0]) & UNIPOLAR;
+       int i;
+
+       for (i = 1; i < cmd->chanlist_len; i++) {
+               unsigned int unipolar = CR_RANGE(cmd->chanlist[i]) & UNIPOLAR;
+
+               if (unipolar != unipolar0) {
+                       dev_dbg(dev->class_dev,
+                               "unipolar and bipolar ranges cannot be mixed in the chanlist\n");
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+
 /* test analog input cmd */
 static int das1800_ai_do_cmdtest(struct comedi_device *dev,
                                 struct comedi_subdevice *s,
@@ -766,8 +786,6 @@ static int das1800_ai_do_cmdtest(struct comedi_device *dev,
        struct das1800_private *devpriv = dev->private;
        int err = 0;
        unsigned int tmp_arg;
-       int i;
-       int unipolar;
 
        /* Step 1 : check if triggers are trivially valid */
 
@@ -873,18 +891,9 @@ static int das1800_ai_do_cmdtest(struct comedi_device *dev,
        if (err)
                return 4;
 
-       /*  make sure user is not trying to mix unipolar and bipolar ranges */
-       if (cmd->chanlist) {
-               unipolar = CR_RANGE(cmd->chanlist[0]) & UNIPOLAR;
-               for (i = 1; i < cmd->chanlist_len; i++) {
-                       if (unipolar != (CR_RANGE(cmd->chanlist[i]) & UNIPOLAR)) {
-                               comedi_error(dev,
-                                            "unipolar and bipolar ranges cannot be mixed in the chanlist");
-                               err++;
-                               break;
-                       }
-               }
-       }
+       /* Step 5: check channel list if it exists */
+       if (cmd->chanlist && cmd->chanlist_len > 0)
+               err |= das1800_ai_check_chanlist(dev, s, cmd);
 
        if (err)
                return 5;