Hi Jacopo,
On Thu, Jun 11, 2020 at 06:16:51PM +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 | 61 ++++++++++++++++++++-
> 1 file changed, 58 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
> index 151e6a90c5fb..11769f004fd8 100644
> --- a/drivers/media/platform/rcar-vin/rcar-csi2.c
> +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
> @@ -363,6 +363,7 @@ 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;
>
> @@ -371,6 +372,7 @@ struct rcar_csi2 {
>
> unsigned short lanes;
> unsigned char lane_swap[4];
> + unsigned short active_lanes;
Do you need this? I.e. should you not always request this from the
transmitter device?
> };
>
> static inline struct rcar_csi2 *sd_to_csi2(struct v4l2_subdev *sd)
> @@ -414,7 +416,7 @@ static int rcsi2_wait_phy_start(struct rcar_csi2 *priv)
>
> /* 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 << priv->active_lanes) - 1;
>
> if ((rcsi2_read(priv, PHCLM_REG) & PHCLM_STOPSTATECKL) &&
> (rcsi2_read(priv, PHDLM_REG) & lane_mask) == lane_mask)
> @@ -471,11 +473,57 @@ 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, priv->active_lanes * 1000000);
>
> return mbps;
> }
>
> +static int rcsi2_config_active_lanes(struct rcar_csi2 *priv)
> +{
> + struct v4l2_mbus_config mbus_config = { 0 };
> + unsigned int num_lanes = (-1U);
> + int ret;
> +
> + priv->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;
This is the downside of using flags... Anyway, I guess this is certainly
fine now.
> +
> + if (num_lanes > priv->lanes) {
> + dev_err(priv->dev,
> + "Unsupported mbus config: too many data lanes %u\n",
> + num_lanes);
> + return -EINVAL;
> + }
> +
> + priv->active_lanes = num_lanes;
> +
> + return 0;
> +}
> +
> static int rcsi2_start_receiver(struct rcar_csi2 *priv)
> {
> const struct rcar_csi2_format *format;
> @@ -490,6 +538,11 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
> /* Code is validated in set_fmt. */
> format = rcsi2_code_to_fmt(priv->mf.code);
>
> + /* Get the remote mbus config to get the number of enabled lanes. */
> + ret = rcsi2_config_active_lanes(priv);
> + if (ret)
> + return ret;
> +
> /*
> * Enable all supported CSI-2 channels with virtual channel and
> * data type matching.
> @@ -522,7 +575,7 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
> }
>
> phycnt = PHYCNT_ENABLECLK;
> - phycnt |= (1 << priv->lanes) - 1;
> + phycnt |= (1 << priv->active_lanes) - 1;
>
> mbps = rcsi2_calc_mbps(priv, format->bpp);
> if (mbps < 0)
> @@ -748,6 +801,7 @@ 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);
>
> @@ -793,6 +847,7 @@ static int rcsi2_parse_v4l2(struct rcar_csi2 *priv,
> priv->lanes);
> return -EINVAL;
> }
> + priv->active_lanes = priv->lanes;
>
> for (i = 0; i < ARRAY_SIZE(priv->lane_swap); i++) {
> priv->lane_swap[i] = i < priv->lanes ?
--
Kind regards,
Sakari Ailus
