iio: xilinx-xadc: Fix ADC-B powerdown

The check for shutting down the second ADC is inverted. This causes it to
be powered down when it should be enabled. As a result channels that are
supposed to be handled by the second ADC return invalid conversion results.

Signed-off-by: Lars-Peter Clausen <[email protected]>
Fixes: bdc8cda ("iio:adc: Add Xilinx XADC driver")
Cc: <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

Author: larsclausen

drivers/iio/adc/xilinx-xadc-core.c

@@ -722,13 +722,14 @@ static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode)
 {
 	uint16_t val;
 
+	/* Powerdown the ADC-B when it is not needed. */
 	switch (seq_mode) {
 	case XADC_CONF1_SEQ_SIMULTANEOUS:
 	case XADC_CONF1_SEQ_INDEPENDENT:
-		val = XADC_CONF2_PD_ADC_B;
+		val = 0;
 		break;
 	default:
-		val = 0;
+		val = XADC_CONF2_PD_ADC_B;
 		break;
 	}