[PATCH v3 2/6] iio: adc: ti-ads7950: do not clobber gpio state in ti_ads7950_get()

[Dmitry Torokhov]

GPIO state was inadvertently overwritten by the result of spi_sync(),
resulting in ti_ads7950_get() only returning 0 as GPIO state (or error).

Fix this by introducing a separate variable to hold the state.

Fixes: c97dce792dc8 ("iio: adc: ti-ads7950: add GPIO support")
Reported-by: David Lechner <dlechner@xxxxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
 drivers/iio/adc/ti-ads7950.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c
index b8cc39fc39fb..cdc624889559 100644
--- a/drivers/iio/adc/ti-ads7950.c
+++ b/drivers/iio/adc/ti-ads7950.c
@@ -427,13 +427,15 @@ static int ti_ads7950_set(struct gpio_chip *chip, unsigned int offset,
 static int ti_ads7950_get(struct gpio_chip *chip, unsigned int offset)
 {
 	struct ti_ads7950_state *st = gpiochip_get_data(chip);
+	bool state;
 	int ret;
 
 	mutex_lock(&st->slock);
 
 	/* If set as output, return the output */
 	if (st->gpio_cmd_settings_bitmask & BIT(offset)) {
-		ret = (st->cmd_settings_bitmask & BIT(offset)) ? 1 : 0;
+		state = st->cmd_settings_bitmask & BIT(offset);
+		ret = 0;
 		goto out;
 	}
 
@@ -444,7 +446,7 @@ static int ti_ads7950_get(struct gpio_chip *chip, unsigned int offset)
 	if (ret)
 		goto out;
 
-	ret = ((st->single_rx >> 12) & BIT(offset)) ? 1 : 0;
+	state = (st->single_rx >> 12) & BIT(offset);
 
 	/* Revert back to original settings */
 	st->cmd_settings_bitmask &= ~TI_ADS7950_CR_GPIO_DATA;
@@ -456,7 +458,7 @@ static int ti_ads7950_get(struct gpio_chip *chip, unsigned int offset)
 out:
 	mutex_unlock(&st->slock);
 
-	return ret;
+	return ret ?: state;
 }
 
 static int ti_ads7950_get_direction(struct gpio_chip *chip,

-- 
2.53.0.473.g4a7958ca14-goog