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 /**
19  * struct drm_writeback_connector - DRM writeback connector
20  */
21 struct drm_writeback_connector {
22 	/**
23 	 * @base: base drm_connector object
24 	 */
25 	struct drm_connector base;
26 
27 	/**
28 	 * @encoder: Internal encoder used by the connector to fulfill
29 	 * the DRM framework requirements. The users of the
30 	 * @drm_writeback_connector control the behaviour of the @encoder
31 	 * by passing the @enc_funcs parameter to drm_writeback_connector_init()
32 	 * function.
33 	 */
34 	struct drm_encoder encoder;
35 
36 	/**
37 	 * @pixel_formats_blob_ptr:
38 	 *
39 	 * DRM blob property data for the pixel formats list on writeback
40 	 * connectors
41 	 * See also drm_writeback_connector_init()
42 	 */
43 	struct drm_property_blob *pixel_formats_blob_ptr;
44 
45 	/** @job_lock: Protects job_queue */
46 	spinlock_t job_lock;
47 
48 	/**
49 	 * @job_queue:
50 	 *
51 	 * Holds a list of a connector's writeback jobs; the last item is the
52 	 * most recent. The first item may be either waiting for the hardware
53 	 * to begin writing, or currently being written.
54 	 *
55 	 * See also: drm_writeback_queue_job() and
56 	 * drm_writeback_signal_completion()
57 	 */
58 	struct list_head job_queue;
59 
60 	/**
61 	 * @fence_context:
62 	 *
63 	 * timeline context used for fence operations.
64 	 */
65 	unsigned int fence_context;
66 	/**
67 	 * @fence_lock:
68 	 *
69 	 * spinlock to protect the fences in the fence_context.
70 	 */
71 	spinlock_t fence_lock;
72 	/**
73 	 * @fence_seqno:
74 	 *
75 	 * Seqno variable used as monotonic counter for the fences
76 	 * created on the connector's timeline.
77 	 */
78 	unsigned long fence_seqno;
79 	/**
80 	 * @timeline_name:
81 	 *
82 	 * The name of the connector's fence timeline.
83 	 */
84 	char timeline_name[32];
85 };
86 
87 /**
88  * struct drm_writeback_job - DRM writeback job
89  */
90 struct drm_writeback_job {
91 	/**
92 	 * @connector:
93 	 *
94 	 * Back-pointer to the writeback connector associated with the job
95 	 */
96 	struct drm_writeback_connector *connector;
97 
98 	/**
99 	 * @prepared:
100 	 *
101 	 * Set when the job has been prepared with drm_writeback_prepare_job()
102 	 */
103 	bool prepared;
104 
105 	/**
106 	 * @cleanup_work:
107 	 *
108 	 * Used to allow drm_writeback_signal_completion to defer dropping the
109 	 * framebuffer reference to a workqueue
110 	 */
111 	struct work_struct cleanup_work;
112 
113 	/**
114 	 * @list_entry:
115 	 *
116 	 * List item for the writeback connector's @job_queue
117 	 */
118 	struct list_head list_entry;
119 
120 	/**
121 	 * @fb:
122 	 *
123 	 * Framebuffer to be written to by the writeback connector. Do not set
124 	 * directly, use drm_writeback_set_fb()
125 	 */
126 	struct drm_framebuffer *fb;
127 
128 	/**
129 	 * @out_fence:
130 	 *
131 	 * Fence which will signal once the writeback has completed
132 	 */
133 	struct dma_fence *out_fence;
134 
135 	/**
136 	 * @priv:
137 	 *
138 	 * Driver-private data
139 	 */
140 	void *priv;
141 };
142 
143 static inline struct drm_writeback_connector *
drm_connector_to_writeback(struct drm_connector * connector)144 drm_connector_to_writeback(struct drm_connector *connector)
145 {
146 	return container_of(connector, struct drm_writeback_connector, base);
147 }
148 
149 int drm_writeback_connector_init(struct drm_device *dev,
150 				 struct drm_writeback_connector *wb_connector,
151 				 const struct drm_connector_funcs *con_funcs,
152 				 const struct drm_encoder_helper_funcs *enc_helper_funcs,
153 				 const u32 *formats, int n_formats);
154 
155 int drm_writeback_set_fb(struct drm_connector_state *conn_state,
156 			 struct drm_framebuffer *fb);
157 
158 int drm_writeback_prepare_job(struct drm_writeback_job *job);
159 
160 void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
161 			     struct drm_connector_state *conn_state);
162 
163 void drm_writeback_cleanup_job(struct drm_writeback_job *job);
164 
165 void
166 drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
167 				int status);
168 
169 struct dma_fence *
170 drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector);
171 #endif
172