1 Texas Instruments OMAP Display Subsystem
2 ========================================
3
4 Generic Description
5 -------------------
6
7 This document is a generic description of the OMAP Display Subsystem bindings.
8 Binding details for each OMAP SoC version are described in respective binding
9 documentation.
10
11 The OMAP Display Subsystem (DSS) hardware consists of DSS Core, DISPC module and
12 a number of encoder modules. All DSS versions contain DSS Core and DISPC, but
13 the encoder modules vary.
14
15 The DSS Core is the parent of the other DSS modules, and manages clock routing,
16 integration to the SoC, etc.
17
18 DISPC is the display controller, which reads pixels from the memory and outputs
19 a RGB pixel stream to encoders.
20
21 The encoder modules encode the received RGB pixel stream to a video output like
22 HDMI, MIPI DPI, etc.
23
24 Video Ports
25 -----------
26
27 The DSS Core and the encoders have video port outputs. The structure of the
28 video ports is described in Documentation/devicetree/bindings/graph.txt,
29 and the properties for the ports and endpoints for each encoder are
30 described in the SoC's DSS binding documentation.
31
32 The video ports are used to describe the connections to external hardware, like
33 panels or external encoders.
34
35 Aliases
36 -------
37
38 The board dts file may define aliases for displays to assign "displayX" style
39 name for each display. If no aliases are defined, a semi-random number is used
40 for the display.
41
42 Example
43 -------
44
45 A shortened example of the DSS description for OMAP4, with non-relevant parts
46 removed, defined in omap4.dtsi:
47
48 dss: dss@58000000 {
49 compatible = "ti,omap4-dss";
50 reg = <0x58000000 0x80>;
51 status = "disabled";
52 ti,hwmods = "dss_core";
53 clocks = <&dss_dss_clk>;
54 clock-names = "fck";
55 #address-cells = <1>;
56 #size-cells = <1>;
57 ranges;
58
59 dispc@58001000 {
60 compatible = "ti,omap4-dispc";
61 reg = <0x58001000 0x1000>;
62 interrupts = <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
63 ti,hwmods = "dss_dispc";
64 clocks = <&dss_dss_clk>;
65 clock-names = "fck";
66 };
67
68 hdmi: encoder@58006000 {
69 compatible = "ti,omap4-hdmi";
70 reg = <0x58006000 0x200>,
71 <0x58006200 0x100>,
72 <0x58006300 0x100>,
73 <0x58006400 0x1000>;
74 reg-names = "wp", "pll", "phy", "core";
75 interrupts = <GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>;
76 status = "disabled";
77 ti,hwmods = "dss_hdmi";
78 clocks = <&dss_48mhz_clk>, <&dss_sys_clk>;
79 clock-names = "fck", "sys_clk";
80 };
81 };
82
83 A shortened example of the board description for OMAP4 Panda board, defined in
84 omap4-panda.dts.
85
86 The Panda board has a DVI and a HDMI connector, and the board contains a TFP410
87 chip (MIPI DPI to DVI encoder) and a TPD12S015 chip (HDMI ESD protection & level
88 shifter). The video pipelines for the connectors are formed as follows:
89
90 DSS Core --(MIPI DPI)--> TFP410 --(DVI)--> DVI Connector
91 OMAP HDMI --(HDMI)--> TPD12S015 --(HDMI)--> HDMI Connector
92
93 / {
94 aliases {
95 display0 = &dvi0;
96 display1 = &hdmi0;
97 };
98
99 tfp410: encoder@0 {
100 compatible = "ti,tfp410";
101 gpios = <&gpio1 0 GPIO_ACTIVE_LOW>; /* 0, power-down */
102
103 pinctrl-names = "default";
104 pinctrl-0 = <&tfp410_pins>;
105
106 ports {
107 #address-cells = <1>;
108 #size-cells = <0>;
109
110 port@0 {
111 reg = <0>;
112
113 tfp410_in: endpoint@0 {
114 remote-endpoint = <&dpi_out>;
115 };
116 };
117
118 port@1 {
119 reg = <1>;
120
121 tfp410_out: endpoint@0 {
122 remote-endpoint = <&dvi_connector_in>;
123 };
124 };
125 };
126 };
127
128 dvi0: connector@0 {
129 compatible = "dvi-connector";
130 label = "dvi";
131
132 i2c-bus = <&i2c3>;
133
134 port {
135 dvi_connector_in: endpoint {
136 remote-endpoint = <&tfp410_out>;
137 };
138 };
139 };
140
141 tpd12s015: encoder@1 {
142 compatible = "ti,tpd12s015";
143
144 pinctrl-names = "default";
145 pinctrl-0 = <&tpd12s015_pins>;
146
147 gpios = <&gpio2 28 GPIO_ACTIVE_HIGH>, /* 60, CT CP HPD */
148 <&gpio2 9 GPIO_ACTIVE_HIGH>, /* 41, LS OE */
149 <&gpio2 31 GPIO_ACTIVE_HIGH>; /* 63, HPD */
150
151 ports {
152 #address-cells = <1>;
153 #size-cells = <0>;
154
155 port@0 {
156 reg = <0>;
157
158 tpd12s015_in: endpoint@0 {
159 remote-endpoint = <&hdmi_out>;
160 };
161 };
162
163 port@1 {
164 reg = <1>;
165
166 tpd12s015_out: endpoint@0 {
167 remote-endpoint = <&hdmi_connector_in>;
168 };
169 };
170 };
171 };
172
173 hdmi0: connector@1 {
174 compatible = "hdmi-connector";
175 label = "hdmi";
176
177 port {
178 hdmi_connector_in: endpoint {
179 remote-endpoint = <&tpd12s015_out>;
180 };
181 };
182 };
183 };
184
185 &dss {
186 status = "ok";
187
188 pinctrl-names = "default";
189 pinctrl-0 = <&dss_dpi_pins>;
190
191 port {
192 dpi_out: endpoint {
193 remote-endpoint = <&tfp410_in>;
194 data-lines = <24>;
195 };
196 };
197 };
198
199 &hdmi {
200 status = "ok";
201 vdda-supply = <&vdac>;
202
203 pinctrl-names = "default";
204 pinctrl-0 = <&dss_hdmi_pins>;
205
206 port {
207 hdmi_out: endpoint {
208 remote-endpoint = <&tpd12s015_in>;
209 };
210 };
211 };
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