xref: /openbmc/linux/include/drm/drm_writeback.h (revision 8795a739) 
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
4  * Author: Brian Starkey <brian.starkey@arm.com>
5  *
6  * This program is free software and is provided to you under the terms of the
7  * GNU General Public License version 2 as published by the Free Software
8  * Foundation, and any use by you of this program is subject to the terms
9  * of such GNU licence.
10  */
11 
12 #ifndef __DRM_WRITEBACK_H__
13 #define __DRM_WRITEBACK_H__
14 #include <drm/drm_connector.h>
15 #include <drm/drm_encoder.h>
16 #include <linux/workqueue.h>
17 
18 struct drm_writeback_connector {
19 	struct drm_connector base;
20 
21 	/**
22 	 * @encoder: Internal encoder used by the connector to fulfill
23 	 * the DRM framework requirements. The users of the
24 	 * @drm_writeback_connector control the behaviour of the @encoder
25 	 * by passing the @enc_funcs parameter to drm_writeback_connector_init()
26 	 * function.
27 	 */
28 	struct drm_encoder encoder;
29 
30 	/**
31 	 * @pixel_formats_blob_ptr:
32 	 *
33 	 * DRM blob property data for the pixel formats list on writeback
34 	 * connectors
35 	 * See also drm_writeback_connector_init()
36 	 */
37 	struct drm_property_blob *pixel_formats_blob_ptr;
38 
39 	/** @job_lock: Protects job_queue */
40 	spinlock_t job_lock;
41 
42 	/**
43 	 * @job_queue:
44 	 *
45 	 * Holds a list of a connector's writeback jobs; the last item is the
46 	 * most recent. The first item may be either waiting for the hardware
47 	 * to begin writing, or currently being written.
48 	 *
49 	 * See also: drm_writeback_queue_job() and
50 	 * drm_writeback_signal_completion()
51 	 */
52 	struct list_head job_queue;
53 
54 	/**
55 	 * @fence_context:
56 	 *
57 	 * timeline context used for fence operations.
58 	 */
59 	unsigned int fence_context;
60 	/**
61 	 * @fence_lock:
62 	 *
63 	 * spinlock to protect the fences in the fence_context.
64 	 */
65 	spinlock_t fence_lock;
66 	/**
67 	 * @fence_seqno:
68 	 *
69 	 * Seqno variable used as monotonic counter for the fences
70 	 * created on the connector's timeline.
71 	 */
72 	unsigned long fence_seqno;
73 	/**
74 	 * @timeline_name:
75 	 *
76 	 * The name of the connector's fence timeline.
77 	 */
78 	char timeline_name[32];
79 };
80 
81 struct drm_writeback_job {
82 	/**
83 	 * @connector:
84 	 *
85 	 * Back-pointer to the writeback connector associated with the job
86 	 */
87 	struct drm_writeback_connector *connector;
88 
89 	/**
90 	 * @prepared:
91 	 *
92 	 * Set when the job has been prepared with drm_writeback_prepare_job()
93 	 */
94 	bool prepared;
95 
96 	/**
97 	 * @cleanup_work:
98 	 *
99 	 * Used to allow drm_writeback_signal_completion to defer dropping the
100 	 * framebuffer reference to a workqueue
101 	 */
102 	struct work_struct cleanup_work;
103 
104 	/**
105 	 * @list_entry:
106 	 *
107 	 * List item for the writeback connector's @job_queue
108 	 */
109 	struct list_head list_entry;
110 
111 	/**
112 	 * @fb:
113 	 *
114 	 * Framebuffer to be written to by the writeback connector. Do not set
115 	 * directly, use drm_writeback_set_fb()
116 	 */
117 	struct drm_framebuffer *fb;
118 
119 	/**
120 	 * @out_fence:
121 	 *
122 	 * Fence which will signal once the writeback has completed
123 	 */
124 	struct dma_fence *out_fence;
125 
126 	/**
127 	 * @priv:
128 	 *
129 	 * Driver-private data
130 	 */
131 	void *priv;
132 };
133 
134 static inline struct drm_writeback_connector *
135 drm_connector_to_writeback(struct drm_connector *connector)
136 {
137 	return container_of(connector, struct drm_writeback_connector, base);
138 }
139 
140 int drm_writeback_connector_init(struct drm_device *dev,
141 				 struct drm_writeback_connector *wb_connector,
142 				 const struct drm_connector_funcs *con_funcs,
143 				 const struct drm_encoder_helper_funcs *enc_helper_funcs,
144 				 const u32 *formats, int n_formats);
145 
146 int drm_writeback_set_fb(struct drm_connector_state *conn_state,
147 			 struct drm_framebuffer *fb);
148 
149 int drm_writeback_prepare_job(struct drm_writeback_job *job);
150 
151 void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
152 			     struct drm_connector_state *conn_state);
153 
154 void drm_writeback_cleanup_job(struct drm_writeback_job *job);
155 
156 void
157 drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
158 				int status);
159 
160 struct dma_fence *
161 drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector);
162 #endif
163