Hi Laurent,
On Sat, Jan 01, 2022 at 08:28:00PM +0200, Laurent Pinchart wrote:
> The MAX9286 can generate a framesync signal to synchronize the cameras,
> using an internal timer. Support this mode of operation and configure it
> through the .s_frameinterval() operation. If the frame interval is not
> 0, framesync is switched to manual mode with the specified interval,
> otherwise automatic mode is used.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> ---
> Changes since v1:
>
> - Use pixel rate to calculate frame sync counter
> ---
Reviewed-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
Thanks
j
> drivers/media/i2c/max9286.c | 84 +++++++++++++++++++++++++++++++++----
> 1 file changed, 75 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> index 15c80034e3a4..75374034724f 100644
> --- a/drivers/media/i2c/max9286.c
> +++ b/drivers/media/i2c/max9286.c
> @@ -170,9 +170,11 @@ struct max9286_priv {
> u32 rev_chan_mv;
>
> struct v4l2_ctrl_handler ctrls;
> - struct v4l2_ctrl *pixelrate;
> + struct v4l2_ctrl *pixelrate_ctrl;
> + unsigned int pixelrate;
>
> struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
> + struct v4l2_fract interval;
>
> /* Protects controls and fmt structures */
> struct mutex mutex;
> @@ -473,6 +475,40 @@ static int max9286_check_config_link(struct max9286_priv *priv,
> return 0;
> }
>
> +static void max9286_set_fsync_period(struct max9286_priv *priv)
> +{
> + u32 fsync;
> +
> + if (!priv->interval.numerator || !priv->interval.denominator) {
> + /*
> + * Special case, a null interval enables automatic FRAMESYNC
> + * mode. FRAMESYNC is taken from the slowest link.
> + */
> + max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
> + MAX9286_FSYNCMETH_AUTO);
> + return;
> + }
> +
> + /*
> + * Manual FRAMESYNC
> + *
> + * 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);
> +
> + dev_dbg(&priv->client->dev, "fsync period %u (pclk %u)\n", fsync,
> + priv->pixelrate);
> +
> + max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_OUT |
> + MAX9286_FSYNCMETH_MANUAL);
> +
> + max9286_write(priv, 0x06, (fsync >> 0) & 0xff);
> + max9286_write(priv, 0x07, (fsync >> 8) & 0xff);
> + max9286_write(priv, 0x08, (fsync >> 16) & 0xff);
> +}
> +
> /* -----------------------------------------------------------------------------
> * V4L2 Subdev
> */
> @@ -511,11 +547,13 @@ static int max9286_set_pixelrate(struct max9286_priv *priv)
> return -EINVAL;
> }
>
> + priv->pixelrate = pixelrate;
> +
> /*
> * The CSI-2 transmitter pixel rate is the single source rate multiplied
> * by the number of available sources.
> */
> - return v4l2_ctrl_s_ctrl_int64(priv->pixelrate,
> + return v4l2_ctrl_s_ctrl_int64(priv->pixelrate_ctrl,
> pixelrate * priv->nsources);
> }
>
> @@ -655,6 +693,8 @@ static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
> int ret;
>
> if (enable) {
> + max9286_set_fsync_period(priv);
> +
> /*
> * The frame sync between cameras is transmitted across the
> * reverse channel as GPIO. We must open all channels while
> @@ -714,6 +754,32 @@ static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
> return 0;
> }
>
> +static int max9286_g_frame_interval(struct v4l2_subdev *sd,
> + struct v4l2_subdev_frame_interval *interval)
> +{
> + struct max9286_priv *priv = sd_to_max9286(sd);
> +
> + if (interval->pad != MAX9286_SRC_PAD)
> + return -EINVAL;
> +
> + interval->interval = priv->interval;
> +
> + return 0;
> +}
> +
> +static int max9286_s_frame_interval(struct v4l2_subdev *sd,
> + struct v4l2_subdev_frame_interval *interval)
> +{
> + struct max9286_priv *priv = sd_to_max9286(sd);
> +
> + if (interval->pad != MAX9286_SRC_PAD)
> + return -EINVAL;
> +
> + priv->interval = interval->interval;
> +
> + return 0;
> +}
> +
> static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
> struct v4l2_subdev_state *sd_state,
> struct v4l2_subdev_mbus_code_enum *code)
> @@ -805,6 +871,8 @@ static int max9286_get_fmt(struct v4l2_subdev *sd,
>
> static const struct v4l2_subdev_video_ops max9286_video_ops = {
> .s_stream = max9286_s_stream,
> + .g_frame_interval = max9286_g_frame_interval,
> + .s_frame_interval = max9286_s_frame_interval,
> };
>
> static const struct v4l2_subdev_pad_ops max9286_pad_ops = {
> @@ -885,10 +953,10 @@ static int max9286_v4l2_register(struct max9286_priv *priv)
> priv->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>
> v4l2_ctrl_handler_init(&priv->ctrls, 1);
> - priv->pixelrate = v4l2_ctrl_new_std(&priv->ctrls,
> - &max9286_ctrl_ops,
> - V4L2_CID_PIXEL_RATE,
> - 1, INT_MAX, 1, 50000000);
> + priv->pixelrate_ctrl = v4l2_ctrl_new_std(&priv->ctrls,
> + &max9286_ctrl_ops,
> + V4L2_CID_PIXEL_RATE,
> + 1, INT_MAX, 1, 50000000);
>
> priv->sd.ctrl_handler = &priv->ctrls;
> ret = priv->ctrls.error;
> @@ -997,9 +1065,7 @@ static int max9286_setup(struct max9286_priv *priv)
> MAX9286_CSILANECNT(priv->csi2_data_lanes) |
> MAX9286_DATATYPE_YUV422_8BIT);
>
> - /* Automatic: FRAMESYNC taken from the slowest Link. */
> - max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
> - MAX9286_FSYNCMETH_AUTO);
> + max9286_set_fsync_period(priv);
>
> /* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
> max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
> --
> Regards,
>
> Laurent Pinchart
>
