On Sonntag, 29. Jänner 2023 12:22:49 CET Jacopo Mondi wrote:
> Hi Luca
>
> On Sun, Jan 29, 2023 at 10:42:35AM +0100, Luca Weiss wrote:
> > In some setups XSHUTDOWN is connected to DOVDD when it's unused,
> > therefore treat the reset gpio as optional.
>
> I don't have a datasheet for this sensor, but OV sensors usually have
> to gpio lines to control powerdown and reset. Datasheets usually
> suggest to hook one of the 2 to DOVDD and control the other from the
> SoC. How is the sensor hooked up in your design ? No gpio lines is
> controlled by the SoC ?
It looks like this sensor only has XSHUTDOWN pin and no extra reset pin.
In my setup there's the normal I2C & CSI & mclk hookups, but the supply lines
and shutdown line are all just connected to regulator-fixed, so gpio-
controlled on/off regulators.
>
> Another question is if we need to software-reset the sensor if no gpio
> line is hooked up to XSHUTDOWN.
The datasheet mentions it resets itself during power up (so when the supplies
are turned on), so I don't think we need to add anything.
Regards
Luca
>
> > Signed-off-by: Luca Weiss <luca@xxxxxxxxx>
> > ---
> >
> > drivers/media/i2c/ov2685.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/i2c/ov2685.c b/drivers/media/i2c/ov2685.c
> > index a3b524f15d89..a422f4c8a2eb 100644
> > --- a/drivers/media/i2c/ov2685.c
> > +++ b/drivers/media/i2c/ov2685.c
> > @@ -734,7 +734,7 @@ static int ov2685_probe(struct i2c_client *client,
> >
> > if (clk_get_rate(ov2685->xvclk) != OV2685_XVCLK_FREQ)
> >
> > dev_warn(dev, "xvclk mismatched, modes are based on
24MHz\n");
> >
> > - ov2685->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> > + ov2685->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> > GPIOD_OUT_LOW);>
> > if (IS_ERR(ov2685->reset_gpio)) {
> >
> > dev_err(dev, "Failed to get reset-gpios\n");
> > return -EINVAL;
> >
> > --
> > 2.39.1
