staging: comedi: mf6x4: introduce a macro to select the AI channel

For aesthetics, use a macro to set the bit in the ADCTRL register that
selects an analog input channel.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
 drivers/staging/comedi/drivers/mf6x4.c | 9 +++++----
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/mf6x4.c b/drivers/staging/comedi/drivers/mf6x4.c
index bde163e..ff4ba15 100644 (file)
--- a/drivers/staging/comedi/drivers/mf6x4.c
+++ b/drivers/staging/comedi/drivers/mf6x4.c
@@ -39,8 +39,8 @@
 
 /* BAR1 registers */
 #define MF6X4_ADDATA_R         0x00
-#define MF6X4_ADCTRL_R         0x00
-#define MF6X4_ADCTRL_M         0xff
+#define MF6X4_ADCTRL_REG       0x00
+#define MF6X4_ADCTRL_CHAN(x)   BIT(chan)
 #define MF6X4_DIN_R            0x10
 #define MF6X4_DIN_M            0xff
 #define MF6X4_DOUT_R           0x10
@@ -133,13 +133,13 @@ static int mf6x4_ai_insn_read(struct comedi_device *dev,
                              struct comedi_insn *insn,
                              unsigned int *data)
 {
-       int chan = CR_CHAN(insn->chanspec);
+       unsigned int chan = CR_CHAN(insn->chanspec);
        int ret;
        int i;
        int d;
 
        /* Set the ADC channel number in the scan list */
-       iowrite16((1 << chan) & MF6X4_ADCTRL_M, dev->mmio + MF6X4_ADCTRL_R);
+       iowrite16(MF6X4_ADCTRL_CHAN(chan), dev->mmio + MF6X4_ADCTRL_REG);
 
        for (i = 0; i < insn->n; i++) {
                /* Trigger ADC conversion by reading ADSTART */
@@ -155,7 +155,7 @@ static int mf6x4_ai_insn_read(struct comedi_device *dev,
                data[i] = d;
        }
 
-       iowrite16(0x0, dev->mmio + MF6X4_ADCTRL_R);
+       iowrite16(0x0, dev->mmio + MF6X4_ADCTRL_REG);
 
        return insn->n;
 }