[PATCH v2] iio: adc: ti-ads124s08: Return reset GPIO lookup errors

[Pengpeng Hou]

devm_gpiod_get_optional() returns NULL when the optional GPIO is absent,
but returns an ERR_PTR when the GPIO provider lookup fails, including
probe deferral.

Probe currently logs the ERR_PTR case as if the reset GPIO were simply
absent and keeps the error pointer in reset_gpio. Later ads124s_reset()
treats any non-NULL reset_gpio as a valid descriptor and passes it to
gpiod_set_value_cansleep().

Return the lookup error instead of retaining the ERR_PTR.

Fixes: e717f8c6dfec ("iio: adc: Add the TI ads124s08 ADC code")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Joshua Crofts <joshua.crofts1@xxxxxxxxx>
Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
---
Changes in v2:
- Split from the v1 combined reset-failure patch.
- Keep only the GPIO ERR_PTR/probe-deferral fix.
- Add the Fixes tag requested by Andy.
- Carry Joshua's Reviewed-by, as allowed for a split version.

 drivers/iio/adc/ti-ads124s08.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ti-ads124s08.c b/drivers/iio/adc/ti-ads124s08.c
index 8ea1269f74db..73ad6ea9ef5d 100644
--- a/drivers/iio/adc/ti-ads124s08.c
+++ b/drivers/iio/adc/ti-ads124s08.c
@@ -321,7 +321,8 @@ static int ads124s_probe(struct spi_device *spi)
 	ads124s_priv->reset_gpio = devm_gpiod_get_optional(&spi->dev,
 						   "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(ads124s_priv->reset_gpio))
-		dev_info(&spi->dev, "Reset GPIO not defined\n");
+		return dev_err_probe(&spi->dev, PTR_ERR(ads124s_priv->reset_gpio),
+				     "Failed to get reset GPIO\n");
 
 	ads124s_priv->chip_info = &ads124s_chip_info_tbl[spi_id->driver_data];
 
-- 
2.50.1