Re: [PATCH v2 11/11] media: max9286: Use frame interval from subdev state

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jacopo,

On Thu, May 09, 2024 at 03:45:11PM +0200, Jacopo Mondi wrote:
> On Thu, May 09, 2024 at 03:51:22PM GMT, Laurent Pinchart wrote:
> > On Mon, May 06, 2024 at 06:49:39PM +0200, Jacopo Mondi wrote:
> > > Use the frame interval stored in the subdev state instead of storing
> > > a copy in the driver private structure.
> > >
> > > Initialize the frame interval to the special case 0/0 that in the
> > > max9286 driver represents automatic handling of frame sync.
> > >
> > > During the startup phase, configure register 0x01 to use automatic
> > > frame sync, to match the subdev state initialiation, instead of calling
> > > max9286_set_fsync_period() which now requires a 'state' argument.
> >
> > Given that max9286_set_fsync_period() will be called at stream start
> > time, is there a need to set the register in max9286_setup() ? If so,
> >
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >
> > If not, you can drop it.
> 
> Ok, I removed it initially then re-introduced in v2

If you drop it, please just record the rationale in the commit message.

> > > Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > > ---
> > >  drivers/media/i2c/max9286.c | 59 +++++++++++++++++++------------------
> > >  1 file changed, 31 insertions(+), 28 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> > > index 7fad190cd9b3..6930a98c8965 100644
> > > --- a/drivers/media/i2c/max9286.c
> > > +++ b/drivers/media/i2c/max9286.c
> > > @@ -197,8 +197,6 @@ struct max9286_priv {
> > >  	struct v4l2_ctrl *pixelrate_ctrl;
> > >  	unsigned int pixelrate;
> > >
> > > -	struct v4l2_fract interval;
> > > -
> > >  	unsigned int nsources;
> > >  	unsigned int source_mask;
> > >  	unsigned int route_mask;
> > > @@ -571,11 +569,14 @@ static void max9286_set_video_format(struct max9286_priv *priv,
> > >  		      MAX9286_INVVS | MAX9286_HVSRC_D14);
> > >  }
> > >
> > > -static void max9286_set_fsync_period(struct max9286_priv *priv)
> > > +static void max9286_set_fsync_period(struct max9286_priv *priv,
> > > +				     struct v4l2_subdev_state *state)
> >
> > Depending on whether this series or "media: v4l2-subdev: Provide
> > const-aware subdev state accessors" gets merged first, this argument
> > could be const :-) No need to address that for now and add a dependency.
> >
> > >  {
> > > +	const struct v4l2_fract *interval;
> > >  	u32 fsync;
> > >
> > > -	if (!priv->interval.numerator || !priv->interval.denominator) {
> > > +	interval = v4l2_subdev_state_get_interval(state, MAX9286_SRC_PAD);
> > > +	if (!interval->numerator || !interval->denominator) {
> > >  		/*
> > >  		 * Special case, a null interval enables automatic FRAMESYNC
> > >  		 * mode. FRAMESYNC is taken from the slowest link.
> > > @@ -591,8 +592,8 @@ static void max9286_set_fsync_period(struct max9286_priv *priv)
> > >  	 * The FRAMESYNC generator is configured with a period expressed as a
> > >  	 * number of PCLK periods.
> > >  	 */
> > > -	fsync = div_u64((u64)priv->pixelrate * priv->interval.numerator,
> > > -			priv->interval.denominator);
> > > +	fsync = div_u64((u64)priv->pixelrate * interval->numerator,
> > > +			interval->denominator);
> > >
> > >  	dev_dbg(&priv->client->dev, "fsync period %u (pclk %u)\n", fsync,
> > >  		priv->pixelrate);
> > > @@ -801,7 +802,7 @@ static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
> > >  		format = v4l2_subdev_state_get_format(state, MAX9286_SRC_PAD);
> > >
> > >  		max9286_set_video_format(priv, format);
> > > -		max9286_set_fsync_period(priv);
> > > +		max9286_set_fsync_period(priv, state);
> > >
> > >  		/*
> > >  		 * The frame sync between cameras is transmitted across the
> > > @@ -874,19 +875,11 @@ static int max9286_get_frame_interval(struct v4l2_subdev *sd,
> > >  				      struct v4l2_subdev_state *sd_state,
> > >  				      struct v4l2_subdev_frame_interval *interval)
> > >  {
> > > -	struct max9286_priv *priv = sd_to_max9286(sd);
> > > -
> > > -	/*
> > > -	 * FIXME: Implement support for V4L2_SUBDEV_FORMAT_TRY, using the V4L2
> > > -	 * subdev active state API.
> > > -	 */
> > > -	if (interval->which != V4L2_SUBDEV_FORMAT_ACTIVE)
> > > -		return -EINVAL;
> > > -
> > >  	if (interval->pad != MAX9286_SRC_PAD)
> > >  		return -EINVAL;
> > >
> > > -	interval->interval = priv->interval;
> > > +	interval->interval = *v4l2_subdev_state_get_interval(sd_state,
> > > +							     interval->pad);
> > >
> > >  	return 0;
> > >  }
> > > @@ -895,19 +888,11 @@ static int max9286_set_frame_interval(struct v4l2_subdev *sd,
> > >  				      struct v4l2_subdev_state *sd_state,
> > >  				      struct v4l2_subdev_frame_interval *interval)
> > >  {
> > > -	struct max9286_priv *priv = sd_to_max9286(sd);
> > > -
> > > -	/*
> > > -	 * FIXME: Implement support for V4L2_SUBDEV_FORMAT_TRY, using the V4L2
> > > -	 * subdev active state API.
> > > -	 */
> > > -	if (interval->which != V4L2_SUBDEV_FORMAT_ACTIVE)
> > > -		return -EINVAL;
> > > -
> > >  	if (interval->pad != MAX9286_SRC_PAD)
> > >  		return -EINVAL;
> > >
> > > -	priv->interval = interval->interval;
> > > +	*v4l2_subdev_state_get_interval(sd_state,
> > > +					interval->pad) = interval->interval;
> > >
> > >  	return 0;
> > >  }
> > > @@ -993,9 +978,21 @@ static const struct v4l2_mbus_framefmt max9286_default_format = {
> > >  static int max9286_init_state(struct v4l2_subdev *sd,
> > >  			      struct v4l2_subdev_state *state)
> > >  {
> > > +	struct v4l2_fract *interval;
> > > +
> > >  	for (unsigned int i = 0; i < MAX9286_N_PADS; i++)
> > >  		*v4l2_subdev_state_get_format(state, i) = max9286_default_format;
> > >
> > > +	/*
> > > +	 * Special case: a null interval enables automatic FRAMESYNC mode.
> > > +	 *
> > > +	 * FRAMESYNC is taken from the slowest link. See register 0x01
> > > +	 * configuration.
> > > +	 */
> > > +	interval = v4l2_subdev_state_get_interval(state, MAX9286_SRC_PAD);
> > > +	interval->numerator = 0;
> > > +	interval->denominator = 0;
> > > +
> > >  	return 0;
> > >  }
> > >
> > > @@ -1142,7 +1139,13 @@ static int max9286_setup(struct max9286_priv *priv)
> > >  	max9286_write(priv, 0x69, (0xf & ~priv->route_mask));
> > >
> > >  	max9286_set_video_format(priv, &max9286_default_format);
> > > -	max9286_set_fsync_period(priv);
> > > +
> > > +	/*
> > > +	 * Use automatic FRAMESYNC mode. FRAMESYNC is taken from the slowest
> > > +	 * link.
> > > +	 */
> > > +	max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
> > > +				  MAX9286_FSYNCMETH_AUTO);
> > >
> > >  	cfg = max9286_read(priv, 0x1c);
> > >  	if (cfg < 0)

-- 
Regards,

Laurent Pinchart