Hi Jacopo,
Thank you for the patch.
On Fri, Mar 19, 2021 at 05:41:43PM +0100, Jacopo Mondi wrote:
> Enable the noise immunity threshold at the end of the rdacm20
> initialization routine.
>
> The rdacm20 camera module has been so far tested with a startup
> delay that allowed the embedded MCU to program the serializer. If
> the initialization routine is run before the MCU programs the
> serializer and the image sensor and their addresses gets changed
> by the rdacm20 driver it is required to manually enable the noise
> immunity threshold to make the communication on the control channel
> more reliable.
>
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/i2c/rdacm20.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/i2c/rdacm20.c b/drivers/media/i2c/rdacm20.c
> index 2881e752efbe..554fd3b3ec3d 100644
> --- a/drivers/media/i2c/rdacm20.c
> +++ b/drivers/media/i2c/rdacm20.c
> @@ -518,7 +518,19 @@ static int rdacm20_init(struct v4l2_subdev *sd, unsigned int val)
>
> dev_info(dev->dev, "Identified MAX9271 + OV10635 device\n");
>
> - return 0;
> + /*
> + * Set reverse channel high threshold to increase noise immunity.
> + *
> + * This should be compensated by increasing the reverse channel
> + * amplitude on the remote deserializer side.
> + *
> + * TODO Inspect the embedded MCU programming sequence to make sure
> + * there are no conflicts with the configuration applied here.
> + *
> + * TODO Clarify the embedded MCU startup delay to avoid write
> + * collisions on the I2C bus.
> + */
> + return max9271_set_high_threshold(&dev->serializer, true);
> }
>
> static const struct v4l2_subdev_core_ops rdacm20_core_ops = {
--
Regards,
Laurent Pinchart
