On Thu, Feb 27, 2020 at 12:59:13AM +0300, Andrey Konovalov wrote: > 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). > I didn't catch this issue since I've been using IMX290 board on top of Sensors mezzanine which has the pullup on that pin. But this fix LGTM. Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> Thanks, Mani > Signed-off-by: Andrey Konovalov <andrey.konovalov@xxxxxxxxxx> > --- > drivers/media/i2c/imx290.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c > index d0322f9a8856..7b1de1f0c8b7 100644 > --- 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); > -- > 2.17.1 >
