staging: comedi: me4000: tidy up the chanlist checking

The ai_check_chanlist() function validates that the cmd->chanlist is compatible
with the hardware. This is step 5 of the (*do_cmdtest).

For aesthetics, rename this function so it has namespace associated with the
driver and tidy up the 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/me4000.c b/drivers/staging/comedi/drivers/me4000.c
index f02b31b..e146555 100644 (file)
--- a/drivers/staging/comedi/drivers/me4000.c
+++ b/drivers/staging/comedi/drivers/me4000.c
@@ -598,67 +598,35 @@ static int me4000_ai_cancel(struct comedi_device *dev,
        return 0;
 }
 
-static int ai_check_chanlist(struct comedi_device *dev,
-                            struct comedi_subdevice *s, struct comedi_cmd *cmd)
+static int me4000_ai_check_chanlist(struct comedi_device *dev,
+                                   struct comedi_subdevice *s,
+                                   struct comedi_cmd *cmd)
 {
-       const struct me4000_board *thisboard = comedi_board(dev);
-       int aref;
+       const struct me4000_board *board = comedi_board(dev);
+       unsigned int max_diff_chan = board->ai_diff_nchan;
+       unsigned int aref0 = CR_AREF(cmd->chanlist[0]);
        int i;
 
-       /* Check whether a channel list is available */
-       if (!cmd->chanlist_len) {
-               dev_err(dev->class_dev, "No channel list available\n");
-               return -EINVAL;
-       }
-
-       /* Check the channel list size */
-       if (cmd->chanlist_len > ME4000_AI_CHANNEL_LIST_COUNT) {
-               dev_err(dev->class_dev, "Channel list is to large\n");
-               return -EINVAL;
-       }
-
-       /* Check the pointer */
-       if (!cmd->chanlist) {
-               dev_err(dev->class_dev, "NULL pointer to channel list\n");
-               return -EFAULT;
-       }
-
-       /* Check whether aref is equal for all entries */
-       aref = CR_AREF(cmd->chanlist[0]);
        for (i = 0; i < cmd->chanlist_len; i++) {
-               if (CR_AREF(cmd->chanlist[i]) != aref) {
-                       dev_err(dev->class_dev,
+               unsigned int chan = CR_CHAN(cmd->chanlist[i]);
+               unsigned int range = CR_RANGE(cmd->chanlist[i]);
+               unsigned int aref = CR_AREF(cmd->chanlist[i]);
+
+               if (aref != aref0) {
+                       dev_dbg(dev->class_dev,
                                "Mode is not equal for all entries\n");
                        return -EINVAL;
                }
-       }
 
-       /* Check whether channels are available for this ending */
-       if (aref == SDF_DIFF) {
-               for (i = 0; i < cmd->chanlist_len; i++) {
-                       if (CR_CHAN(cmd->chanlist[i]) >=
-                           thisboard->ai_diff_nchan) {
-                               dev_err(dev->class_dev,
+               if (aref == SDF_DIFF) {
+                       if (chan >= max_diff_chan) {
+                               dev_dbg(dev->class_dev,
                                        "Channel number to high\n");
                                return -EINVAL;
                        }
-               }
-       } else {
-               for (i = 0; i < cmd->chanlist_len; i++) {
-                       if (CR_CHAN(cmd->chanlist[i]) >= thisboard->ai_nchan) {
-                               dev_err(dev->class_dev,
-                                       "Channel number to high\n");
-                               return -EINVAL;
-                       }
-               }
-       }
 
-       /* Check if bipolar is set for all entries when in differential mode */
-       if (aref == SDF_DIFF) {
-               for (i = 0; i < cmd->chanlist_len; i++) {
-                       if (CR_RANGE(cmd->chanlist[i]) != 1 &&
-                           CR_RANGE(cmd->chanlist[i]) != 2) {
-                               dev_err(dev->class_dev,
+                       if (!comedi_range_is_bipolar(s, range)) {
+                               dev_dbg(dev->class_dev,
                                       "Bipolar is not selected in differential mode\n");
                                return -EINVAL;
                        }
@@ -1091,10 +1059,11 @@ static int me4000_ai_do_cmd_test(struct comedi_device *dev,
        if (err)
                return 4;
 
-       /*
-        * Stage 5. Check the channel list.
-        */
-       if (ai_check_chanlist(dev, s, cmd))
+       /* Step 5: check channel list if it exists */
+       if (cmd->chanlist && cmd->chanlist_len > 0)
+               err |= me4000_ai_check_chanlist(dev, s, cmd);
+
+       if (err)
                return 5;
 
        return 0;