Hi Jacopo,
Thanks for your work.
On 2020-07-14 15:58:12 +0200, Jacopo Mondi wrote:
> Use the newly introduced get_mbus_config() subdevice pad operation to
> retrieve the remote subdevice MIPI CSI-2 bus configuration and configure
> the number of active data lanes accordingly.
>
> In order to be able to call the remote subdevice operation cache the
> index of the remote pad connected to the single CSI-2 input port.
>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> ---
> drivers/media/platform/rcar-vin/rcar-csi2.c | 74 +++++++++++++++++++--
> 1 file changed, 67 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
> index c6cc4f473a07..d39f312ebff9 100644
> --- a/drivers/media/platform/rcar-vin/rcar-csi2.c
> +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
> @@ -364,6 +364,7 @@ struct rcar_csi2 {
> struct v4l2_async_notifier notifier;
> struct v4l2_async_subdev asd;
> struct v4l2_subdev *remote;
> + unsigned int remote_pad;
>
> struct v4l2_mbus_framefmt mf;
>
> @@ -409,13 +410,14 @@ static void rcsi2_exit_standby(struct rcar_csi2 *priv)
> reset_control_deassert(priv->rstc);
> }
>
> -static int rcsi2_wait_phy_start(struct rcar_csi2 *priv)
> +static int rcsi2_wait_phy_start(struct rcar_csi2 *priv,
> + unsigned int active_lanes)
Maybe s/active_lanes/lanes/ here and below?
> {
> unsigned int timeout;
>
> /* Wait for the clock and data lanes to enter LP-11 state. */
> for (timeout = 0; timeout <= 20; timeout++) {
> - const u32 lane_mask = (1 << priv->lanes) - 1;
> + const u32 lane_mask = (1 << active_lanes) - 1;
>
> if ((rcsi2_read(priv, PHCLM_REG) & PHCLM_STOPSTATECKL) &&
> (rcsi2_read(priv, PHDLM_REG) & lane_mask) == lane_mask)
> @@ -447,7 +449,8 @@ static int rcsi2_set_phypll(struct rcar_csi2 *priv, unsigned int mbps)
> return 0;
> }
>
> -static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp)
> +static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp,
> + unsigned int active_lanes)
> {
> struct v4l2_subdev *source;
> struct v4l2_ctrl *ctrl;
> @@ -472,15 +475,63 @@ static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp)
> * bps = link_freq * 2
> */
> mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * bpp;
> - do_div(mbps, priv->lanes * 1000000);
> + do_div(mbps, active_lanes * 1000000);
>
> return mbps;
> }
>
> +static int rcsi2_config_active_lanes(struct rcar_csi2 *priv,
> + unsigned int *active_lanes)
I would name this rcsi2_get_active_lanes() as it does not configure
anything just queries the subdevice for information.
> +{
> + struct v4l2_mbus_config mbus_config = { 0 };
> + unsigned int num_lanes = (-1U);
This looks odd and could just be set 0 with the same effect but clearer
to read.
> + int ret;
> +
> + *active_lanes = priv->lanes;
> + ret = v4l2_subdev_call(priv->remote, pad, get_mbus_config,
> + priv->remote_pad, &mbus_config);
> + if (ret == -ENOIOCTLCMD) {
> + dev_dbg(priv->dev, "No remote mbus configuration available\n");
> + return 0;
> + }
> +
> + if (ret) {
> + dev_err(priv->dev, "Failed to get remote mbus configuration\n");
> + return ret;
> + }
> +
> + if (mbus_config.type != V4L2_MBUS_CSI2_DPHY) {
> + dev_err(priv->dev, "Unsupported media bus type %u\n",
> + mbus_config.type);
> + return -EINVAL;
> + }
> +
> + if (mbus_config.flags & V4L2_MBUS_CSI2_1_LANE)
> + num_lanes = 1;
> + else if (mbus_config.flags & V4L2_MBUS_CSI2_2_LANE)
> + num_lanes = 2;
> + else if (mbus_config.flags & V4L2_MBUS_CSI2_3_LANE)
> + num_lanes = 3;
> + else if (mbus_config.flags & V4L2_MBUS_CSI2_4_LANE)
> + num_lanes = 4;
> +
> + if (num_lanes > priv->lanes) {
> + dev_err(priv->dev,
> + "Unsupported mbus config: too many data lanes %u\n",
> + num_lanes);
> + return -EINVAL;
> + }
> +
> + *active_lanes = num_lanes;
> +
> + return 0;
> +}
> +
> static int rcsi2_start_receiver(struct rcar_csi2 *priv)
> {
> const struct rcar_csi2_format *format;
> u32 phycnt, vcdt = 0, vcdt2 = 0, fld = 0;
> + unsigned int active_lanes;
> unsigned int i;
> int mbps, ret;
>
> @@ -522,10 +573,18 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
> fld |= FLD_FLD_NUM(1);
> }
>
> + /*
> + * Get the number of active data lanes inspecting the remote mbus
> + * configuration.
> + */
> + ret = rcsi2_config_active_lanes(priv, &active_lanes);
> + if (ret)
> + return ret;
> +
> phycnt = PHYCNT_ENABLECLK;
> - phycnt |= (1 << priv->lanes) - 1;
> + phycnt |= (1 << active_lanes) - 1;
>
> - mbps = rcsi2_calc_mbps(priv, format->bpp);
> + mbps = rcsi2_calc_mbps(priv, format->bpp, active_lanes);
> if (mbps < 0)
> return mbps;
>
> @@ -572,7 +631,7 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
> rcsi2_write(priv, PHYCNT_REG, phycnt | PHYCNT_SHUTDOWNZ);
> rcsi2_write(priv, PHYCNT_REG, phycnt | PHYCNT_SHUTDOWNZ | PHYCNT_RSTZ);
>
> - ret = rcsi2_wait_phy_start(priv);
> + ret = rcsi2_wait_phy_start(priv, active_lanes);
> if (ret)
> return ret;
>
> @@ -749,6 +808,7 @@ static int rcsi2_notify_bound(struct v4l2_async_notifier *notifier,
> }
>
> priv->remote = subdev;
> + priv->remote_pad = pad;
>
> dev_dbg(priv->dev, "Bound %s pad: %d\n", subdev->name, pad);
>
> --
> 2.27.0
>
--
Regards,
Niklas Söderlund
