staging: comedi: das16: 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 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/das16.c b/drivers/staging/comedi/drivers/das16.c
index 6a7d652..eb774c3 100644 (file)
--- a/drivers/staging/comedi/drivers/das16.c
+++ b/drivers/staging/comedi/drivers/das16.c
@@ -600,13 +600,40 @@ static void das16_timer_interrupt(unsigned long arg)
                mod_timer(&devpriv->timer, jiffies + timer_period());
 }
 
+static int das16_ai_check_chanlist(struct comedi_device *dev,
+                                  struct comedi_subdevice *s,
+                                  struct comedi_cmd *cmd)
+{
+       unsigned int chan0 = CR_CHAN(cmd->chanlist[0]);
+       unsigned int range0 = CR_RANGE(cmd->chanlist[0]);
+       int i;
+
+       for (i = 1; i < cmd->chanlist_len; i++) {
+               unsigned int chan = CR_CHAN(cmd->chanlist[i]);
+               unsigned int range = CR_RANGE(cmd->chanlist[i]);
+
+               if (chan != ((chan0 + i) % s->n_chan)) {
+                       dev_dbg(dev->class_dev,
+                               "entries in chanlist must be consecutive channels, counting upwards\n");
+                       return -EINVAL;
+               }
+
+               if (range != range0) {
+                       dev_dbg(dev->class_dev,
+                               "entries in chanlist must all have the same gain\n");
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+
 static int das16_cmd_test(struct comedi_device *dev, struct comedi_subdevice *s,
                          struct comedi_cmd *cmd)
 {
        const struct das16_board *board = comedi_board(dev);
        struct das16_private_struct *devpriv = dev->private;
        int err = 0, tmp;
-       int gain, start_chan, i;
        int mask;
 
        /* Step 1 : check if triggers are trivially valid */
@@ -693,24 +720,10 @@ static int das16_cmd_test(struct comedi_device *dev, struct comedi_subdevice *s,
        if (err)
                return 4;
 
-       /*  check channel/gain list against card's limitations */
-       if (cmd->chanlist) {
-               gain = CR_RANGE(cmd->chanlist[0]);
-               start_chan = CR_CHAN(cmd->chanlist[0]);
-               for (i = 1; i < cmd->chanlist_len; i++) {
-                       if (CR_CHAN(cmd->chanlist[i]) !=
-                           (start_chan + i) % s->n_chan) {
-                               dev_err(dev->class_dev,
-                                       "entries in chanlist must be consecutive channels, counting upwards\n");
-                               err++;
-                       }
-                       if (CR_RANGE(cmd->chanlist[i]) != gain) {
-                               dev_err(dev->class_dev,
-                                       "entries in chanlist must all have the same gain\n");
-                               err++;
-                       }
-               }
-       }
+       /* Step 5: check channel list if it exists */
+       if (cmd->chanlist && cmd->chanlist_len > 0)
+               err |= das16_ai_check_chanlist(dev, s, cmd);
+
        if (err)
                return 5;