Hi Laurent, On Sat, Jan 01, 2022 at 08:28:06PM +0200, Laurent Pinchart wrote: > GMSL can transport three synchronization signals: VSync, HSync and Data > Enable. The MAX9286 can select either HS or DE as a line valid signal. > > Not all serializers (and transmission formats) support the DE signal. > The MAX9271, used by the RDACM20 and RDACM21 cameras, doesn't document > DE support. Nonetheless, the max9286 driver selects the DE signal as > line valid in register 0x0c (by not setting the DESEL bit). It's not > clear why this works. As HS is a more common line valid qualifier, set > the DESEL bit by default. This is needed to support the onsemi MARS > cameras. > > If a camera requires usage of the DE signal in the future, this will > need to be made configurable. Tested-by: Jacopo Mondi <jacopo@xxxxxxxxxx> On Eagle V3M with RDACM20 Reviewed-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> Thanks j > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx> > --- > drivers/media/i2c/max9286.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c > index 07ebb01640a1..446fc238d642 100644 > --- a/drivers/media/i2c/max9286.c > +++ b/drivers/media/i2c/max9286.c > @@ -563,9 +563,12 @@ static void max9286_set_video_format(struct max9286_priv *priv, > MAX9286_CSILANECNT(priv->csi2_data_lanes) | > info->datatype); > > - /* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */ > - max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS | > - MAX9286_HVSRC_D14); > + /* > + * Enable HS/VS encoding, use HS as line valid source, use D14/15 for > + * HS/VS, invert VS. > + */ > + max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_DESEL | > + MAX9286_INVVS | MAX9286_HVSRC_D14); > } > > static void max9286_set_fsync_period(struct max9286_priv *priv) > -- > Regards, > > Laurent Pinchart >
