2 * Copyright (c) 2016 Intel Corporation
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23 #include <linux/export.h>
25 #include <drm/drm_encoder.h>
27 #include "drm_crtc_internal.h"
32 * Encoders represent the connecting element between the CRTC (as the overall
33 * pixel pipeline, represented by struct &drm_crtc) and the connectors (as the
34 * generic sink entity, represented by struct &drm_connector). An encoder takes
35 * pixel data from a CRTC and converts it to a format suitable for any attached
36 * connector. Encoders are objects exposed to userspace, originally to allow
37 * userspace to infer cloning and connector/CRTC restrictions. Unfortunately
38 * almost all drivers get this wrong, making the uabi pretty much useless. On
39 * top of that the exposed restrictions are too simple for today's hardware, and
40 * the recommended way to infer restrictions is by using the
41 * DRM_MODE_ATOMIC_TEST_ONLY flag for the atomic IOCTL.
43 * Otherwise encoders aren't used in the uapi at all (any modeset request from
44 * userspace directly connects a connector with a CRTC), drivers are therefore
45 * free to use them however they wish. Modeset helper libraries make strong use
46 * of encoders to facilitate code sharing. But for more complex settings it is
47 * usually better to move shared code into a separate &drm_bridge. Compared to
48 * encoders, bridges also have the benefit of being purely an internal
49 * abstraction since they are not exposed to userspace at all.
51 * Encoders are initialized with drm_encoder_init() and cleaned up using
52 * drm_encoder_cleanup().
54 static const struct drm_prop_enum_list drm_encoder_enum_list
[] = {
55 { DRM_MODE_ENCODER_NONE
, "None" },
56 { DRM_MODE_ENCODER_DAC
, "DAC" },
57 { DRM_MODE_ENCODER_TMDS
, "TMDS" },
58 { DRM_MODE_ENCODER_LVDS
, "LVDS" },
59 { DRM_MODE_ENCODER_TVDAC
, "TV" },
60 { DRM_MODE_ENCODER_VIRTUAL
, "Virtual" },
61 { DRM_MODE_ENCODER_DSI
, "DSI" },
62 { DRM_MODE_ENCODER_DPMST
, "DP MST" },
63 { DRM_MODE_ENCODER_DPI
, "DPI" },
66 int drm_encoder_register_all(struct drm_device
*dev
)
68 struct drm_encoder
*encoder
;
71 drm_for_each_encoder(encoder
, dev
) {
72 if (encoder
->funcs
->late_register
)
73 ret
= encoder
->funcs
->late_register(encoder
);
81 void drm_encoder_unregister_all(struct drm_device
*dev
)
83 struct drm_encoder
*encoder
;
85 drm_for_each_encoder(encoder
, dev
) {
86 if (encoder
->funcs
->early_unregister
)
87 encoder
->funcs
->early_unregister(encoder
);
92 * drm_encoder_init - Init a preallocated encoder
94 * @encoder: the encoder to init
95 * @funcs: callbacks for this encoder
96 * @encoder_type: user visible type of the encoder
97 * @name: printf style format string for the encoder name, or NULL for default name
99 * Initialises a preallocated encoder. Encoder should be subclassed as part of
100 * driver encoder objects. At driver unload time drm_encoder_cleanup() should be
101 * called from the driver's destroy hook in &drm_encoder_funcs.
104 * Zero on success, error code on failure.
106 int drm_encoder_init(struct drm_device
*dev
,
107 struct drm_encoder
*encoder
,
108 const struct drm_encoder_funcs
*funcs
,
109 int encoder_type
, const char *name
, ...)
113 ret
= drm_mode_object_get(dev
, &encoder
->base
, DRM_MODE_OBJECT_ENCODER
);
118 encoder
->encoder_type
= encoder_type
;
119 encoder
->funcs
= funcs
;
124 encoder
->name
= kvasprintf(GFP_KERNEL
, name
, ap
);
127 encoder
->name
= kasprintf(GFP_KERNEL
, "%s-%d",
128 drm_encoder_enum_list
[encoder_type
].name
,
131 if (!encoder
->name
) {
136 list_add_tail(&encoder
->head
, &dev
->mode_config
.encoder_list
);
137 encoder
->index
= dev
->mode_config
.num_encoder
++;
141 drm_mode_object_unregister(dev
, &encoder
->base
);
145 EXPORT_SYMBOL(drm_encoder_init
);
148 * drm_encoder_cleanup - cleans up an initialised encoder
149 * @encoder: encoder to cleanup
151 * Cleans up the encoder but doesn't free the object.
153 void drm_encoder_cleanup(struct drm_encoder
*encoder
)
155 struct drm_device
*dev
= encoder
->dev
;
157 /* Note that the encoder_list is considered to be static; should we
158 * remove the drm_encoder at runtime we would have to decrement all
159 * the indices on the drm_encoder after us in the encoder_list.
162 drm_mode_object_unregister(dev
, &encoder
->base
);
163 kfree(encoder
->name
);
164 list_del(&encoder
->head
);
165 dev
->mode_config
.num_encoder
--;
167 memset(encoder
, 0, sizeof(*encoder
));
169 EXPORT_SYMBOL(drm_encoder_cleanup
);
171 static struct drm_crtc
*drm_encoder_get_crtc(struct drm_encoder
*encoder
)
173 struct drm_connector
*connector
;
174 struct drm_device
*dev
= encoder
->dev
;
175 bool uses_atomic
= false;
177 /* For atomic drivers only state objects are synchronously updated and
178 * protected by modeset locks, so check those first. */
179 drm_for_each_connector(connector
, dev
) {
180 if (!connector
->state
)
185 if (connector
->state
->best_encoder
!= encoder
)
188 return connector
->state
->crtc
;
191 /* Don't return stale data (e.g. pending async disable). */
195 return encoder
->crtc
;
198 int drm_mode_getencoder(struct drm_device
*dev
, void *data
,
199 struct drm_file
*file_priv
)
201 struct drm_mode_get_encoder
*enc_resp
= data
;
202 struct drm_encoder
*encoder
;
203 struct drm_crtc
*crtc
;
205 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
208 encoder
= drm_encoder_find(dev
, enc_resp
->encoder_id
);
212 drm_modeset_lock(&dev
->mode_config
.connection_mutex
, NULL
);
213 crtc
= drm_encoder_get_crtc(encoder
);
215 enc_resp
->crtc_id
= crtc
->base
.id
;
217 enc_resp
->crtc_id
= 0;
218 drm_modeset_unlock(&dev
->mode_config
.connection_mutex
);
220 enc_resp
->encoder_type
= encoder
->encoder_type
;
221 enc_resp
->encoder_id
= encoder
->base
.id
;
222 enc_resp
->possible_crtcs
= encoder
->possible_crtcs
;
223 enc_resp
->possible_clones
= encoder
->possible_clones
;