staging: comedi: dmm32at: 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/dmm32at.c b/drivers/staging/comedi/drivers/dmm32at.c
index c8a36eb5f01573d07a36fa2852fa12a3c56c1583..68260e6658e425f7ab631b8c447e35a5c4eb6e24 100644 (file)
--- a/drivers/staging/comedi/drivers/dmm32at.c
+++ b/drivers/staging/comedi/drivers/dmm32at.c
@@ -243,13 +243,39 @@ static int dmm32at_ns_to_timer(unsigned int *ns, int round)
        return *ns;
 }
 
+static int dmm32at_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 dmm32at_ai_cmdtest(struct comedi_device *dev,
                              struct comedi_subdevice *s,
                              struct comedi_cmd *cmd)
 {
        int err = 0;
        int tmp;
-       int start_chan, gain, i;
 
        /* Step 1 : check if triggers are trivially valid */
 
@@ -349,26 +375,9 @@ static int dmm32at_ai_cmdtest(struct comedi_device *dev,
        if (err)
                return 4;
 
-       /* step 5 check the channel list, the channel list for this
-          board must be consecutive and gains must be the same */
-
-       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) {
-                               comedi_error(dev,
-                                            "entries in chanlist must be consecutive channels, counting upwards\n");
-                               err++;
-                       }
-                       if (CR_RANGE(cmd->chanlist[i]) != gain) {
-                               comedi_error(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 |= dmm32at_ai_check_chanlist(dev, s, cmd);
 
        if (err)
                return 5;