media: i2c: imx290: fix reset GPIO pin handling

According to https://www.kernel.org/doc/Documentation/gpio/consumer.txt,

- all of the gpiod_set_value_xxx() functions operate with the *logical*
value. So in imx290_power_on() the reset signal should be cleared
(de-asserted) with gpiod_set_value_cansleep(imx290->rst_gpio, 0), and in
imx290_power_off() the value of 1 must be used to apply/assert the reset
to the sensor. In the device tree the reset pin is described as
GPIO_ACTIVE_LOW, and gpiod_set_value_xxx() functions take this into
account,

- when devm_gpiod_get_optional() is called with GPIOD_ASIS, the GPIO is
not initialized, and the direction must be set later; using a GPIO
without setting its direction first is illegal and will result in undefined
behavior. Fix this by using GPIOD_OUT_HIGH instead of GPIOD_ASIS (this
asserts the reset signal to the sensor initially).

Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
index d0322f9..7b1de1f 100644 (file)
--- a/drivers/media/i2c/imx290.c
+++ b/drivers/media/i2c/imx290.c
@@ -628,7 +628,7 @@ static int imx290_power_on(struct device *dev)
        }
 
        usleep_range(1, 2);
-       gpiod_set_value_cansleep(imx290->rst_gpio, 1);
+       gpiod_set_value_cansleep(imx290->rst_gpio, 0);
        usleep_range(30000, 31000);
 
        return 0;
@@ -641,7 +641,7 @@ static int imx290_power_off(struct device *dev)
        struct imx290 *imx290 = to_imx290(sd);
 
        clk_disable_unprepare(imx290->xclk);
-       gpiod_set_value_cansleep(imx290->rst_gpio, 0);
+       gpiod_set_value_cansleep(imx290->rst_gpio, 1);
        regulator_bulk_disable(IMX290_NUM_SUPPLIES, imx290->supplies);
 
        return 0;
@@ -757,7 +757,8 @@ static int imx290_probe(struct i2c_client *client)
                goto free_err;
        }
 
-       imx290->rst_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_ASIS);
+       imx290->rst_gpio = devm_gpiod_get_optional(dev, "reset",
+                                                  GPIOD_OUT_HIGH);
        if (IS_ERR(imx290->rst_gpio)) {
                dev_err(dev, "Cannot get reset gpio\n");
                ret = PTR_ERR(imx290->rst_gpio);