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1/*
2 * Copyright (C) 2013, NVIDIA Corporation. All rights reserved.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sub license,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the
12 * next paragraph) shall be included in all copies or substantial portions
13 * of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24#ifndef __DRM_PANEL_H__
25#define __DRM_PANEL_H__
26
27#include <linux/err.h>
28#include <linux/errno.h>
29#include <linux/list.h>
30
31struct device_node;
32struct drm_connector;
33struct drm_device;
34struct drm_panel;
35struct display_timing;
36
37/**
38 * struct drm_panel_funcs - perform operations on a given panel
39 *
40 * The .prepare() function is typically called before the display controller
41 * starts to transmit video data. Panel drivers can use this to turn the panel
42 * on and wait for it to become ready. If additional configuration is required
43 * (via a control bus such as I2C, SPI or DSI for example) this is a good time
44 * to do that.
45 *
46 * After the display controller has started transmitting video data, it's safe
47 * to call the .enable() function. This will typically enable the backlight to
48 * make the image on screen visible. Some panels require a certain amount of
49 * time or frames before the image is displayed. This function is responsible
50 * for taking this into account before enabling the backlight to avoid visual
51 * glitches.
52 *
53 * Before stopping video transmission from the display controller it can be
54 * necessary to turn off the panel to avoid visual glitches. This is done in
55 * the .disable() function. Analogously to .enable() this typically involves
56 * turning off the backlight and waiting for some time to make sure no image
57 * is visible on the panel. It is then safe for the display controller to
58 * cease transmission of video data.
59 *
60 * To save power when no video data is transmitted, a driver can power down
61 * the panel. This is the job of the .unprepare() function.
62 */
63struct drm_panel_funcs {
64 /**
65 * @prepare:
66 *
67 * Turn on panel and perform set up.
68 */
69 int (*prepare)(struct drm_panel *panel);
70
71 /**
72 * @enable:
73 *
74 * Enable panel (turn on back light, etc.).
75 */
76 int (*enable)(struct drm_panel *panel);
77
78 /**
79 * @disable:
80 *
81 * Disable panel (turn off back light, etc.).
82 */
83 int (*disable)(struct drm_panel *panel);
84
85 /**
86 * @unprepare:
87 *
88 * Turn off panel.
89 */
90 int (*unprepare)(struct drm_panel *panel);
91
92 /**
93 * @get_modes:
94 *
95 * Add modes to the connector that the panel is attached to and
96 * return the number of modes added.
97 */
98 int (*get_modes)(struct drm_panel *panel);
99
100 /**
101 * @get_timings:
102 *
103 * Copy display timings into the provided array and return
104 * the number of display timings available.
105 */
106 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
107 struct display_timing *timings);
108};
109
110/**
111 * struct drm_panel - DRM panel object
112 */
113struct drm_panel {
114 /**
115 * @drm:
116 *
117 * DRM device owning the panel.
118 */
119 struct drm_device *drm;
120
121 /**
122 * @connector:
123 *
124 * DRM connector that the panel is attached to.
125 */
126 struct drm_connector *connector;
127
128 /**
129 * @dev:
130 *
131 * Parent device of the panel.
132 */
133 struct device *dev;
134
135 /**
136 * @funcs:
137 *
138 * Operations that can be performed on the panel.
139 */
140 const struct drm_panel_funcs *funcs;
141
142 /**
143 * @list:
144 *
145 * Panel entry in registry.
146 */
147 struct list_head list;
148};
149
150void drm_panel_init(struct drm_panel *panel);
151
152int drm_panel_add(struct drm_panel *panel);
153void drm_panel_remove(struct drm_panel *panel);
154
155int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector);
156void drm_panel_detach(struct drm_panel *panel);
157
158int drm_panel_prepare(struct drm_panel *panel);
159int drm_panel_unprepare(struct drm_panel *panel);
160
161int drm_panel_enable(struct drm_panel *panel);
162int drm_panel_disable(struct drm_panel *panel);
163
164int drm_panel_get_modes(struct drm_panel *panel);
165
166#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
167struct drm_panel *of_drm_find_panel(const struct device_node *np);
168#else
169static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
170{
171 return ERR_PTR(-ENODEV);
172}
173#endif
174
175#endif
1/*
2 * Copyright (C) 2013, NVIDIA Corporation. All rights reserved.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sub license,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the
12 * next paragraph) shall be included in all copies or substantial portions
13 * of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24#ifndef __DRM_PANEL_H__
25#define __DRM_PANEL_H__
26
27#include <linux/errno.h>
28#include <linux/list.h>
29
30struct device_node;
31struct drm_connector;
32struct drm_device;
33struct drm_panel;
34struct display_timing;
35
36/**
37 * struct drm_panel_funcs - perform operations on a given panel
38 * @disable: disable panel (turn off back light, etc.)
39 * @unprepare: turn off panel
40 * @prepare: turn on panel and perform set up
41 * @enable: enable panel (turn on back light, etc.)
42 * @get_modes: add modes to the connector that the panel is attached to and
43 * return the number of modes added
44 * @get_timings: copy display timings into the provided array and return
45 * the number of display timings available
46 *
47 * The .prepare() function is typically called before the display controller
48 * starts to transmit video data. Panel drivers can use this to turn the panel
49 * on and wait for it to become ready. If additional configuration is required
50 * (via a control bus such as I2C, SPI or DSI for example) this is a good time
51 * to do that.
52 *
53 * After the display controller has started transmitting video data, it's safe
54 * to call the .enable() function. This will typically enable the backlight to
55 * make the image on screen visible. Some panels require a certain amount of
56 * time or frames before the image is displayed. This function is responsible
57 * for taking this into account before enabling the backlight to avoid visual
58 * glitches.
59 *
60 * Before stopping video transmission from the display controller it can be
61 * necessary to turn off the panel to avoid visual glitches. This is done in
62 * the .disable() function. Analogously to .enable() this typically involves
63 * turning off the backlight and waiting for some time to make sure no image
64 * is visible on the panel. It is then safe for the display controller to
65 * cease transmission of video data.
66 *
67 * To save power when no video data is transmitted, a driver can power down
68 * the panel. This is the job of the .unprepare() function.
69 */
70struct drm_panel_funcs {
71 int (*disable)(struct drm_panel *panel);
72 int (*unprepare)(struct drm_panel *panel);
73 int (*prepare)(struct drm_panel *panel);
74 int (*enable)(struct drm_panel *panel);
75 int (*get_modes)(struct drm_panel *panel);
76 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
77 struct display_timing *timings);
78};
79
80/**
81 * struct drm_panel - DRM panel object
82 * @drm: DRM device owning the panel
83 * @connector: DRM connector that the panel is attached to
84 * @dev: parent device of the panel
85 * @funcs: operations that can be performed on the panel
86 * @list: panel entry in registry
87 */
88struct drm_panel {
89 struct drm_device *drm;
90 struct drm_connector *connector;
91 struct device *dev;
92
93 const struct drm_panel_funcs *funcs;
94
95 struct list_head list;
96};
97
98/**
99 * drm_disable_unprepare - power off a panel
100 * @panel: DRM panel
101 *
102 * Calling this function will completely power off a panel (assert the panel's
103 * reset, turn off power supplies, ...). After this function has completed, it
104 * is usually no longer possible to communicate with the panel until another
105 * call to drm_panel_prepare().
106 *
107 * Return: 0 on success or a negative error code on failure.
108 */
109static inline int drm_panel_unprepare(struct drm_panel *panel)
110{
111 if (panel && panel->funcs && panel->funcs->unprepare)
112 return panel->funcs->unprepare(panel);
113
114 return panel ? -ENOSYS : -EINVAL;
115}
116
117/**
118 * drm_panel_disable - disable a panel
119 * @panel: DRM panel
120 *
121 * This will typically turn off the panel's backlight or disable the display
122 * drivers. For smart panels it should still be possible to communicate with
123 * the integrated circuitry via any command bus after this call.
124 *
125 * Return: 0 on success or a negative error code on failure.
126 */
127static inline int drm_panel_disable(struct drm_panel *panel)
128{
129 if (panel && panel->funcs && panel->funcs->disable)
130 return panel->funcs->disable(panel);
131
132 return panel ? -ENOSYS : -EINVAL;
133}
134
135/**
136 * drm_panel_prepare - power on a panel
137 * @panel: DRM panel
138 *
139 * Calling this function will enable power and deassert any reset signals to
140 * the panel. After this has completed it is possible to communicate with any
141 * integrated circuitry via a command bus.
142 *
143 * Return: 0 on success or a negative error code on failure.
144 */
145static inline int drm_panel_prepare(struct drm_panel *panel)
146{
147 if (panel && panel->funcs && panel->funcs->prepare)
148 return panel->funcs->prepare(panel);
149
150 return panel ? -ENOSYS : -EINVAL;
151}
152
153/**
154 * drm_panel_enable - enable a panel
155 * @panel: DRM panel
156 *
157 * Calling this function will cause the panel display drivers to be turned on
158 * and the backlight to be enabled. Content will be visible on screen after
159 * this call completes.
160 *
161 * Return: 0 on success or a negative error code on failure.
162 */
163static inline int drm_panel_enable(struct drm_panel *panel)
164{
165 if (panel && panel->funcs && panel->funcs->enable)
166 return panel->funcs->enable(panel);
167
168 return panel ? -ENOSYS : -EINVAL;
169}
170
171/**
172 * drm_panel_get_modes - probe the available display modes of a panel
173 * @panel: DRM panel
174 *
175 * The modes probed from the panel are automatically added to the connector
176 * that the panel is attached to.
177 *
178 * Return: The number of modes available from the panel on success or a
179 * negative error code on failure.
180 */
181static inline int drm_panel_get_modes(struct drm_panel *panel)
182{
183 if (panel && panel->funcs && panel->funcs->get_modes)
184 return panel->funcs->get_modes(panel);
185
186 return panel ? -ENOSYS : -EINVAL;
187}
188
189void drm_panel_init(struct drm_panel *panel);
190
191int drm_panel_add(struct drm_panel *panel);
192void drm_panel_remove(struct drm_panel *panel);
193
194int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector);
195int drm_panel_detach(struct drm_panel *panel);
196
197#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
198struct drm_panel *of_drm_find_panel(const struct device_node *np);
199#else
200static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
201{
202 return NULL;
203}
204#endif
205
206#endif