iio: adc: ti-ads7950: do not clobber gpio state in ti_ads7950_get()

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@baylibre.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c
index b8cc39fc39fba9cca09650c324d6d1ec41e7f0dd..cdc6248895593322b2839ecdf0f7b795411fa1a7 100644 (file)
--- 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,