From: Daniel Vetter Date: Tue, 12 Feb 2019 16:46:15 +0000 (+0100) Subject: drm/doc: document recommended component helper usage X-Git-Tag: v5.15~303^2~28^2~5666 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=86ab67dfcfc5a2e2ee9c6bce08909add48477952;p=platform%2Fkernel%2Flinux-starfive.git drm/doc: document recommended component helper usage Now that component has docs it's worth spending a few words and hyperlinks on recommended best practices in drm. v2: Add another item that component shouldn't be preferred over drm_bridge/panel and similar subsystems already providing specialized support for specific components (Laurent). Also convert to bullet list. Cc: Laurent Pinchart Cc: Russell King - ARM Linux admin Reviewed-by: Maxime Ripard Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20190212164615.13370-1-daniel.vetter@ffwll.ch --- diff --git a/Documentation/driver-api/component.rst b/Documentation/driver-api/component.rst index 2da4a8f..57e3759 100644 --- a/Documentation/driver-api/component.rst +++ b/Documentation/driver-api/component.rst @@ -1,3 +1,5 @@ +.. _component: + ====================================== Component Helper for Aggregate Drivers ====================================== diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst index 3ae23a5..966bd2d 100644 --- a/Documentation/gpu/drm-internals.rst +++ b/Documentation/gpu/drm-internals.rst @@ -93,6 +93,11 @@ Device Instance and Driver Handling Driver Load ----------- +Component Helper Usage +~~~~~~~~~~~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/drm_drv.c + :doc: component helper usage recommendations IRQ Helper Library ~~~~~~~~~~~~~~~~~~ diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 381581b..4fec551 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -457,6 +457,31 @@ static void drm_fs_inode_free(struct inode *inode) } /** + * DOC: component helper usage recommendations + * + * DRM drivers that drive hardware where a logical device consists of a pile of + * independent hardware blocks are recommended to use the :ref:`component helper + * library`. For consistency and better options for code reuse the + * following guidelines apply: + * + * - The entire device initialization procedure should be run from the + * &component_master_ops.master_bind callback, starting with drm_dev_init(), + * then binding all components with component_bind_all() and finishing with + * drm_dev_register(). + * + * - The opaque pointer passed to all components through component_bind_all() + * should point at &struct drm_device of the device instance, not some driver + * specific private structure. + * + * - The component helper fills the niche where further standardization of + * interfaces is not practical. When there already is, or will be, a + * standardized interface like &drm_bridge or &drm_panel, providing its own + * functions to find such components at driver load time, like + * drm_of_find_panel_or_bridge(), then the component helper should not be + * used. + */ + +/** * drm_dev_init - Initialise new DRM device * @dev: DRM device * @driver: DRM driver