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From:   Alexandru Ardelean <aardelean@deviqon.com>
To:     linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     jic23@kernel.org, Jonathan.Cameron@huawei.com,
        alexandru.tachici@analog.com, linux@deviqon.com,
        Alexandru Ardelean <aardelean@deviqon.com>
Subject: [PATCH v2 04/12] iio: adc: ad7192: handle zero Avdd regulator value as error
Date:   Tue, 11 May 2021 10:18:23 +0300
Message-Id: <20210511071831.576145-5-aardelean@deviqon.com>
In-Reply-To: <20210511071831.576145-1-aardelean@deviqon.com>
References: <20210511071831.576145-1-aardelean@deviqon.com>
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This change fixes a corner-case, where the returned voltage is actually
zero. This is also what patch ab0afa65bbc7 ("staging: iio: adc: ad7192:
fail probe on get_voltage") was trying to do.

But as Jonathan pointed out, a zero-value would signal that the probe has
succeeded, putting the driver is a semi-initialized state.

Fixes: ab0afa65bbc7 ("staging: iio: adc: ad7192: fail probe on get_voltage")
Cc: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
---
 drivers/iio/adc/ad7192.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index d3be67aa0522..79df54e0dc96 100644
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -950,6 +950,11 @@ static int ad7192_probe(struct spi_device *spi)
 	}
 
 	voltage_uv = regulator_get_voltage(st->avdd);
+	if (voltage_uv == 0) {
+		ret = -EINVAL;
+		dev_err(&spi->dev, "Zero value provided for AVdd supply\n");
+		goto error_disable_avdd;
+	}
 
 	if (voltage_uv > 0) {
 		st->int_vref_mv = voltage_uv / 1000;
-- 
2.31.1