staging: comedi: me4000: remove unnecessary ME4000_AI_LIST_INPUT_SINGLE_ENDED

This define evaluates to 0 and is OR'ed with the 'entry' value that is
written to the ME4000_AI_CHANNEL_LIST_REG when the channel aref is a
single-ended type (AREF_GROUND or AREF_COMMON). OR'ing a zero value is
pretty silly, just remove it.

Remove the switch() in me4000_ai_insn_read() to simplify the code.

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 0a85ea5..ba3313c 100644 (file)
--- a/drivers/staging/comedi/drivers/me4000.c
+++ b/drivers/staging/comedi/drivers/me4000.c
@@ -110,7 +110,6 @@ broken.
 #define ME4000_AI_STATUS_BIT_FSM               (1 << 29)
 #define ME4000_AI_CTRL_BIT_EX_TRIG_BOTH                (1 << 31)
 #define ME4000_AI_CHANNEL_LIST_REG             0x78
-#define ME4000_AI_LIST_INPUT_SINGLE_ENDED      (0 << 5)
 #define ME4000_AI_LIST_INPUT_DIFFERENTIAL      (1 << 5)
 #define ME4000_AI_LIST_RANGE_BIPOLAR_10                (0 << 6)
 #define ME4000_AI_LIST_RANGE_BIPOLAR_2_5       (1 << 6)
@@ -474,13 +473,8 @@ static int me4000_ai_insn_read(struct comedi_device *dev,
                return -EINVAL;
        }
 
-       switch (aref) {
-       case AREF_GROUND:
-       case AREF_COMMON:
-               entry |= ME4000_AI_LIST_INPUT_SINGLE_ENDED | chan;
-               break;
-
-       case AREF_DIFF:
+       entry |= chan;
+       if (aref == AREF_DIFF) {
                if (!(s->subdev_flags && SDF_DIFF)) {
                        dev_err(dev->class_dev,
                                "Differential inputs are not available\n");
@@ -498,11 +492,7 @@ static int me4000_ai_insn_read(struct comedi_device *dev,
                                "Analog input is not available\n");
                        return -EINVAL;
                }
-               entry |= ME4000_AI_LIST_INPUT_DIFFERENTIAL | chan;
-               break;
-       default:
-               dev_err(dev->class_dev, "Invalid aref specified\n");
-               return -EINVAL;
+               entry |= ME4000_AI_LIST_INPUT_DIFFERENTIAL;
        }
 
        entry |= ME4000_AI_LIST_LAST_ENTRY;
@@ -703,8 +693,6 @@ static int ai_write_chanlist(struct comedi_device *dev,
 
                if (aref == AREF_DIFF)
                        entry |= ME4000_AI_LIST_INPUT_DIFFERENTIAL;
-               else
-                       entry |= ME4000_AI_LIST_INPUT_SINGLE_ENDED;
 
                outl(entry, dev->iobase + ME4000_AI_CHANNEL_LIST_REG);
        }