31.07.2020 12:02, Sowjanya Komatineni пишет:
...
> @@ -249,13 +249,47 @@ static int tegra_csi_enable_stream(struct v4l2_subdev 
> *subdev)
>               return ret;
>       }
>  
> +     if (csi_chan->mipi) {
> +             ret = tegra_mipi_enable(csi_chan->mipi);
> +             if (ret < 0) {
> +                     dev_err(csi->dev,
> +                             "failed to enable MIPI pads: %d\n", ret);
> +                     goto rpm_put;
> +             }
> +
> +             /*
> +              * CSI MIPI pads PULLUP, PULLDN and TERM impedances need to
> +              * be calibrated after power on.
> +              * So, trigger the calibration start here and results will
> +              * be latched and applied to the pads when link is in LP11
> +              * state during start of sensor streaming.
> +              */
> +             ret = tegra_mipi_start_calibration(csi_chan->mipi);
> +             if (ret < 0) {
> +                     dev_err(csi->dev,
> +                             "failed to start MIPI calibration: %d\n", ret);
> +                     goto disable_mipi;
> +             }

What would happen if CSI stream is enabled and then immediately disabled
without enabling camera sensor?

> +     }
> +
...
>  static int tegra_channel_enable_stream(struct tegra_vi_channel *chan)
>  {
>       struct v4l2_subdev *csi_subdev, *src_subdev;
> +     struct tegra_csi_channel *csi_chan;
>       int ret;
>  
>       /*
> @@ -206,13 +207,30 @@ static int tegra_channel_enable_stream(struct 
> tegra_vi_channel *chan)
>       if (IS_ENABLED(CONFIG_VIDEO_TEGRA_TPG))
>               return 0;
>  
> +     csi_chan = v4l2_get_subdevdata(csi_subdev);
> +     /*
> +      * TRM has incorrectly documented to wait for done status from
> +      * calibration logic after CSI interface power on.
> +      * As per the design, calibration results are latched and applied
> +      * to the pads only when the link is in LP11 state which will happen
> +      * during the sensor stream-on.
> +      * CSI subdev stream-on triggers start of MIPI pads calibration.
> +      * Wait for calibration to finish here after sensor subdev stream-on
> +      * and in case of sensor stream-on failure, cancel the calibration.
> +      */
>       src_subdev = tegra_channel_get_remote_source_subdev(chan);

Is it possible to move the start_calibration() here?

>       ret = v4l2_subdev_call(src_subdev, video, s_stream, true);
>       if (ret < 0 && ret != -ENOIOCTLCMD) {
> +             tegra_mipi_cancel_calibration(csi_chan->mipi);
>               v4l2_subdev_call(csi_subdev, video, s_stream, false);
>               return ret;
>       }
>  
> +     ret = tegra_mipi_finish_calibration(csi_chan->mipi);
> +     if (ret < 0)
> +             dev_warn(csi_chan->csi->dev,
> +                      "MIPI calibration failed: %d\n", ret);
> +
>       return 0;
>  }
>  
> 

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