staging: comedi: me4000: simplify analog input range programming
The comedi_lrange table for the analog inputs is inverted compared
to the values that need to be written to the ME4000_AI_CHANNEL_LIST_REG
to select the range.
Create a macro, ME4000_AI_LIST_RANGE(), to handle the inversion. Remove
the old defines and simplify the code a bit.
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 ba3313c..1001d63 100644
--- a/drivers/staging/comedi/drivers/me4000.c
+++ b/drivers/staging/comedi/drivers/me4000.c
@@ -111,10 +111,7 @@
#define ME4000_AI_CTRL_BIT_EX_TRIG_BOTH (1 << 31)
#define ME4000_AI_CHANNEL_LIST_REG 0x78
#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)
-#define ME4000_AI_LIST_RANGE_UNIPOLAR_10 (2 << 6)
-#define ME4000_AI_LIST_RANGE_UNIPOLAR_2_5 (3 << 6)
+#define ME4000_AI_LIST_RANGE(x) ((3 - ((x) & 3)) << 6)
#define ME4000_AI_LIST_LAST_ENTRY (1 << 8)
#define ME4000_AI_DATA_REG 0x7c
#define ME4000_AI_CHAN_TIMER_REG 0x80
@@ -301,6 +298,12 @@
},
};
+/*
+ * NOTE: the ranges here are inverted compared to the values
+ * written to the ME4000_AI_CHANNEL_LIST_REG,
+ *
+ * The ME4000_AI_LIST_RANGE() macro handles the inversion.
+ */
static const struct comedi_lrange me4000_ai_range = {
4, {
UNI_RANGE(2.5),
@@ -455,24 +458,7 @@
return -EINVAL;
}
- switch (rang) {
- case 0:
- entry |= ME4000_AI_LIST_RANGE_UNIPOLAR_2_5;
- break;
- case 1:
- entry |= ME4000_AI_LIST_RANGE_UNIPOLAR_10;
- break;
- case 2:
- entry |= ME4000_AI_LIST_RANGE_BIPOLAR_2_5;
- break;
- case 3:
- entry |= ME4000_AI_LIST_RANGE_BIPOLAR_10;
- break;
- default:
- dev_err(dev->class_dev, "Invalid range specified\n");
- return -EINVAL;
- }
-
+ entry |= ME4000_AI_LIST_RANGE(rang);
entry |= chan;
if (aref == AREF_DIFF) {
if (!(s->subdev_flags && SDF_DIFF)) {
@@ -680,16 +666,7 @@
rang = CR_RANGE(cmd->chanlist[i]);
aref = CR_AREF(cmd->chanlist[i]);
- entry = chan;
-
- if (rang == 0)
- entry |= ME4000_AI_LIST_RANGE_UNIPOLAR_2_5;
- else if (rang == 1)
- entry |= ME4000_AI_LIST_RANGE_UNIPOLAR_10;
- else if (rang == 2)
- entry |= ME4000_AI_LIST_RANGE_BIPOLAR_2_5;
- else
- entry |= ME4000_AI_LIST_RANGE_BIPOLAR_10;
+ entry = chan | ME4000_AI_LIST_RANGE(rang);
if (aref == AREF_DIFF)
entry |= ME4000_AI_LIST_INPUT_DIFFERENTIAL;