From 3150c7d0c686ffee9e414ccce705c34ebcbf4e30 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Thu, 6 Nov 2014 20:53:29 +0100 Subject: drm: Docbook integration and over sections for all the new helpers In all cases the text requires that new drivers are converted to the atomic interfaces. v2: Add overview for state handling. v3: Review from Sean: Some spelling fixes and drop the misguided hunk to remove rgba8888 from the plane helpers compat list. Cc: Sean Paul Reviewed-by: Sean Paul Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_plane_helper.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'drivers/gpu/drm/drm_plane_helper.c') diff --git a/drivers/gpu/drm/drm_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c index a5a295872fbb..fa56bb5da6c3 100644 --- a/drivers/gpu/drm/drm_plane_helper.c +++ b/drivers/gpu/drm/drm_plane_helper.c @@ -31,6 +31,32 @@ #define SUBPIXEL_MASK 0xffff +/** + * DOC: overview + * + * This helper library has two parts. The first part has support to implement + * primary plane support on top of the normal CRTC configuration interface. + * Since the legacy ->set_config interface ties the primary plane together with + * the CRTC state this does not allow userspace to disable the primary plane + * itself. To avoid too much duplicated code use + * drm_plane_helper_check_update() which can be used to enforce the same + * restrictions as primary planes had thus. The default primary plane only + * expose XRBG8888 and ARGB8888 as valid pixel formats for the attached + * framebuffer. + * + * Drivers are highly recommended to implement proper support for primary + * planes, and newly merged drivers must not rely upon these transitional + * helpers. + * + * The second part also implements transitional helpers which allow drivers to + * gradually switch to the atomic helper infrastructure for plane updates. Once + * that switch is complete drivers shouldn't use these any longer, instead using + * the proper legacy implementations for update and disable plane hooks provided + * by the atomic helpers. + * + * Again drivers are strongly urged to switch to the new interfaces. + */ + /* * This is the minimal list of formats that seem to be safe for modeset use * with all current DRM drivers. Most hardware can actually support more -- cgit v1.2.3