• Sean Paul's avatar
    drm: Add Content Protection property · 24557865
    Sean Paul authored
    This patch adds a new optional connector property to allow userspace to enable
    protection over the content it is displaying. This will typically be implemented
    by the driver using HDCP.
    
    The property is a tri-state with the following values:
    - OFF: Self explanatory, no content protection
    - DESIRED: Userspace requests that the driver enable protection
    - ENABLED: Once the driver has authenticated the link, it sets this value
    
    The driver is responsible for downgrading ENABLED to DESIRED if the link becomes
    unprotected. The driver should also maintain the desiredness of protection
    across hotplug/dpms/suspend.
    
    If this looks familiar, I posted [1] this 3 years ago. We have been using this
    in ChromeOS across exynos, mediatek, and rockchip over that time.
    
    Changes in v2:
     - Pimp kerneldoc for content_protection_property (Daniel)
     - Drop sysfs attribute
    Changes in v3:
     - None
    Changes in v4:
    - Changed kerneldoc to recommend userspace polling (Daniel)
    - Changed kerneldoc to briefly describe how to attach the property (Daniel)
    Changes in v5:
    - checkpatch whitespace noise
    - Change DRM_MODE_CONTENT_PROTECTION_OFF to DRM_MODE_CONTENT_PROTECTION_UNDESIRED
    Changes in v6:
    - None
    Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
    Signed-off-by: default avatarSean Paul <seanpaul@chromium.org>
    
    [1] https://lists.freedesktop.org/archives/dri-devel/2014-December/073336.html
    Link: https://patchwork.freedesktop.org/patch/msgid/20180108195545.218615-4-seanpaul@chromium.org
    24557865
drm_connector.h 37.4 KB