From e44ec7794d88f918805d700240211a9ec05ed89d Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars@metafoo.de>
Date: Fri, 3 Apr 2020 15:27:13 +0200
Subject: [PATCH] iio: xilinx-xadc: Fix ADC-B powerdown
Git-commit: e44ec7794d88f918805d700240211a9ec05ed89d
Patch-mainline: v5.7-rc3
References: bsc#1051510

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 <lars@metafoo.de>
Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/iio/adc/xilinx-xadc-core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c
index ec227b358cd6..f50e04a8b0ec 100644
--- a/drivers/iio/adc/xilinx-xadc-core.c
+++ b/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;
 	}
 
-- 
2.16.4