From 935774cd71fe604cc8ed24adcb507d7784255672 Mon Sep 17 00:00:00 2001 From: Brian Starkey Date: Wed, 29 Mar 2017 17:42:32 +0100 Subject: drm: Add writeback connector type Writeback connectors represent writeback engines which can write the CRTC output to a memory framebuffer. Add a writeback connector type and related support functions. Drivers should initialize a writeback connector with drm_writeback_connector_init() which takes care of setting up all the writeback-specific details on top of the normal functionality of drm_connector_init(). Writeback connectors have a WRITEBACK_FB_ID property, used to set the output framebuffer, and a WRITEBACK_PIXEL_FORMATS blob used to expose the supported writeback formats to userspace. When a framebuffer is attached to a writeback connector with the WRITEBACK_FB_ID property, it is used only once (for the commit in which it was included), and userspace can never read back the value of WRITEBACK_FB_ID. WRITEBACK_FB_ID can only be set if the connector is attached to a CRTC. Changes since v1: - Added drm_writeback.c + documentation - Added helper to initialize writeback connector in one go - Added core checks - Squashed into a single commit - Dropped the client cap - Writeback framebuffers are no longer persistent Changes since v2: Daniel Vetter: - Subclass drm_connector to drm_writeback_connector - Relax check to allow CRTC to be set without an FB - Add some writeback_ prefixes - Drop PIXEL_FORMATS_SIZE property, as it was unnecessary Gustavo Padovan: - Add drm_writeback_job to handle writeback signalling centrally Changes since v3: - Rebased - Rename PIXEL_FORMATS -> WRITEBACK_PIXEL_FORMATS Chances since v4: - Embed a drm_encoder inside the drm_writeback_connector to reduce the amount of boilerplate code required from the drivers that are using it. Changes since v5: - Added Rob Clark's atomic_commit() vfunc to connector helper funcs, so that writeback jobs are committed from atomic helpers - Updated create_writeback_properties() signature to return an error code rather than a boolean false for failure. - Free writeback job with the connector state rather than when doing the cleanup_work() Changes since v7: - fix extraneous use of out_fence that is only introduced in a subsequent patch. Changes since v8: - whitespace changes pull from subsequent patch Changes since v9: - Revert the v6 changes that free the writeback job in the connector state cleanup and return to doing it in the cleanup_work() function Signed-off-by: Brian Starkey [rebased and fixed conflicts] Signed-off-by: Mihail Atanassov [rebased and added atomic_commit() vfunc for writeback jobs] Signed-off-by: Rob Clark Signed-off-by: Liviu Dudau Reviewed-by: Eric Anholt Link: https://patchwork.freedesktop.org/patch/229037/ --- include/drm/drm_writeback.h | 91 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 include/drm/drm_writeback.h (limited to 'include/drm/drm_writeback.h') diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h new file mode 100644 index 000000000000..17cd1feecd7e --- /dev/null +++ b/include/drm/drm_writeback.h @@ -0,0 +1,91 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * (C) COPYRIGHT 2016 ARM Limited. All rights reserved. + * Author: Brian Starkey + * + * This program is free software and is provided to you under the terms of the + * GNU General Public License version 2 as published by the Free Software + * Foundation, and any use by you of this program is subject to the terms + * of such GNU licence. + */ + +#ifndef __DRM_WRITEBACK_H__ +#define __DRM_WRITEBACK_H__ +#include +#include +#include + +struct drm_writeback_connector { + struct drm_connector base; + + /** + * @encoder: Internal encoder used by the connector to fulfill + * the DRM framework requirements. The users of the + * @drm_writeback_connector control the behaviour of the @encoder + * by passing the @enc_funcs parameter to drm_writeback_connector_init() + * function. + */ + struct drm_encoder encoder; + + /** + * @pixel_formats_blob_ptr: + * + * DRM blob property data for the pixel formats list on writeback + * connectors + * See also drm_writeback_connector_init() + */ + struct drm_property_blob *pixel_formats_blob_ptr; + + /** @job_lock: Protects job_queue */ + spinlock_t job_lock; + + /** + * @job_queue: + * + * Holds a list of a connector's writeback jobs; the last item is the + * most recent. The first item may be either waiting for the hardware + * to begin writing, or currently being written. + * + * See also: drm_writeback_queue_job() and + * drm_writeback_signal_completion() + */ + struct list_head job_queue; +}; + +struct drm_writeback_job { + /** + * @cleanup_work: + * + * Used to allow drm_writeback_signal_completion to defer dropping the + * framebuffer reference to a workqueue + */ + struct work_struct cleanup_work; + + /** + * @list_entry: + * + * List item for the writeback connector's @job_queue + */ + struct list_head list_entry; + + /** + * @fb: + * + * Framebuffer to be written to by the writeback connector. Do not set + * directly, use drm_atomic_set_writeback_fb_for_connector() + */ + struct drm_framebuffer *fb; +}; + +int drm_writeback_connector_init(struct drm_device *dev, + struct drm_writeback_connector *wb_connector, + const struct drm_connector_funcs *con_funcs, + const struct drm_encoder_helper_funcs *enc_helper_funcs, + const u32 *formats, int n_formats); + +void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector, + struct drm_writeback_job *job); + +void drm_writeback_cleanup_job(struct drm_writeback_job *job); +void drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector); +#endif -- cgit v1.2.3-59-g8ed1b