[PATCH RFT] gpio: zevio: Get correct gpio output value

[Axel Lin <axel.lin@ingics.com>]

Read gpio output value from ZEVIO_GPIO_OUTPUT.
The spin_lock is required to ensure the direction is not changed before reading
input/output value.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
---
Hi Fabian,
The document only mentions:
  +10 (R/W): Direction (set bit to 0 for output, 1 for input)
  +14 (R/W): GPIO output bit
  +18 (R): Reads GPIO input bit.
So I'm not sure if reading ZEVIO_GPIO_INPUT returns correct status when the
direction is output. So I think this needs test.

Regards,
Axel
 drivers/gpio/gpio-zevio.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-zevio.c b/drivers/gpio/gpio-zevio.c
index 9bf5034..29b0150 100644
--- a/drivers/gpio/gpio-zevio.c
+++ b/drivers/gpio/gpio-zevio.c
@@ -81,9 +81,15 @@ static inline void zevio_gpio_port_set(struct zevio_gpio *c, unsigned pin,
 static int zevio_gpio_get(struct gpio_chip *chip, unsigned pin)
 {
 	struct zevio_gpio *controller = to_zevio_gpio(chip);
+	u32 val, dir;
 
-	/* Only reading allowed, so no spinlock needed */
-	u32 val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_INPUT);
+	spin_lock(&controller->lock);
+	dir = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_DIRECTION);
+	if (dir | BIT(ZEVIO_GPIO_BIT(pin)))
+		val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_INPUT);
+	else
+		val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_OUTPUT);
+	spin_unlock(&controller->lock);
 
 	return (val >> ZEVIO_GPIO_BIT(pin)) & 0x1;
 }
-- 
1.8.3.2