1 # SPDX-License-Identifier: (GPL-2.0-only OR BS
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/display/pan
5 $schema: http://devicetree.org/meta-schemas/co
6
7 title: Probeable (via DP AUX / EDID) eDP Panel
8
9 maintainers:
10 - Douglas Anderson <dianders@chromium.org>
11
12 description: |
13 This binding file can be used to indicate th
14 to a Embedded DisplayPort AUX bus (see displ
15 actually specifying exactly what panel is co
16 the case that more than one different panel
17 board, either for second-sourcing purposes o
18 with different LCDs that hook up to a common
19
20 As per above, a requirement for using this b
21 represented under the DP AUX bus. This means
22 information provided by the DP AUX bus (incl
23 the panel. We can use this to identify displ
24 timings among other things.
25
26 One piece of information about eDP panels th
27 provided anywhere on the DP AUX bus is the p
28 This is the reason why, historically, we've
29 list eDP panels. We solve that here with two
30 power on timings for any panels expected to
31 specified in these bindings. Once we've powe
32 the operating system will lookup the panel i
33 information) to figure out other power seque
34
35 eDP panels in general can have somewhat arbi
36 requirements. However, even though it's arbi
37 vast majority of panel datasheets have a pow
38 looks the exactly the same as every other pa
39 cares about different timings in this diagra
40 diagram is so similar means we can come up w
41 handle it.
42
43 These diagrams all look roughly like this, s
44 slightly different numbers / lines but all p
45 sequence. This is because much of this diagr
46 the eDP Standard.
47
48 ______________________________
49 Vdd ___/:
50 _/ :
51 :<T1>:<T2>:
52 : +-----------------------+
53 eDP -----------+ Black video |
54 Display : +-----------------------+
55 : _______________________:
56 HPD :<T3>| :
57 ___________| :
58 : :
59 Sink +-----------------------:
60 AUX CH -----------+ AUX Ch operational :
61 +-----------------------:
62 : :
63 :<T4>: :<T7>:
64 Src main +------+------+-----
65 lnk data----------------+LnkTrn| Idle |Valid
66 +------+------+-----
67 : <T5> :<-T6->:<-T8-
68
69 LED_EN
70 ____________________________________
71
72 _________
73 PWM |
74 __________________________|
75 :
76 _____________:_________
77 Bklight ____/: :
78 power _______/ :<---T13---->:
79 (Vbl) :<T17>:<---------T14---------
80
81 The above looks fairly complex but, as per a
82 about a subset of those timings.
83
84 allOf:
85 - $ref: panel-common.yaml#
86
87 properties:
88 compatible:
89 const: edp-panel
90
91 hpd-reliable-delay-ms:
92 description:
93 A fixed amount of time that must be wait
94 panel's power-supply before the HPD sign
95 when the AUX channel is ready. This is u
96 the HPD at the start of power-on. This v
97 always reliable for all panels that migh
98
99 hpd-absent-delay-ms:
100 description:
101 The panel specifies that HPD will be ass
102 from power on (timing T3 in the diagram
103 measure HPD then a fixed delay of this m
104 This can also be used as a timeout when
105 include the hpd-reliable-delay, so if hp
106 and hpd-absent-delay was 200 ms then we'
107 then we know HPD would assert in the nex
108 needed if HPD hooked up, either through
109 hooked up directly to the eDP controller
110
111 backlight: true
112 enable-gpios: true
113 port: true
114 power-supply: true
115 no-hpd: true
116 hpd-gpios: true
117
118 additionalProperties: false
119
120 required:
121 - compatible
122 - power-supply
123
124 examples:
125 - |
126 #include <dt-bindings/clock/qcom,rpmh.h>
127 #include <dt-bindings/gpio/gpio.h>
128 #include <dt-bindings/interrupt-controller
129
130 i2c {
131 #address-cells = <1>;
132 #size-cells = <0>;
133
134 bridge@2d {
135 compatible = "ti,sn65dsi86";
136 reg = <0x2d>;
137
138 interrupt-parent = <&tlmm>;
139 interrupts = <10 IRQ_TYPE_LEVEL_HIGH>;
140
141 enable-gpios = <&tlmm 102 GPIO_ACTIVE_
142
143 vpll-supply = <&src_pp1800_s4a>;
144 vccio-supply = <&src_pp1800_s4a>;
145 vcca-supply = <&src_pp1200_l2a>;
146 vcc-supply = <&src_pp1200_l2a>;
147
148 clocks = <&rpmhcc RPMH_LN_BB_CLK2>;
149 clock-names = "refclk";
150
151 no-hpd;
152
153 ports {
154 #address-cells = <1>;
155 #size-cells = <0>;
156
157 port@0 {
158 reg = <0>;
159 endpoint {
160 remote-endpoint = <&dsi0_out>;
161 };
162 };
163
164 port@1 {
165 reg = <1>;
166 sn65dsi86_out: endpoint {
167 remote-endpoint = <&panel_in_edp
168 };
169 };
170 };
171
172 aux-bus {
173 panel {
174 compatible = "edp-panel";
175 power-supply = <&pp3300_dx_edp>;
176 backlight = <&backlight>;
177 hpd-gpios = <&sn65dsi86_bridge 2 G
178 hpd-reliable-delay-ms = <15>;
179
180 port {
181 panel_in_edp: endpoint {
182 remote-endpoint = <&sn65dsi86_
183 };
184 };
185 };
186 };
187 };
188 };
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