1Texas Instruments OMAP Display Subsystem
2========================================
3
4Generic Description
5-------------------
6
7This document is a generic description of the OMAP Display Subsystem bindings.
8Binding details for each OMAP SoC version are described in respective binding
9documentation.
10
11The OMAP Display Subsystem (DSS) hardware consists of DSS Core, DISPC module and
12a number of encoder modules. All DSS versions contain DSS Core and DISPC, but
13the encoder modules vary.
14
15The DSS Core is the parent of the other DSS modules, and manages clock routing,
16integration to the SoC, etc.
17
18DISPC is the display controller, which reads pixels from the memory and outputs
19a RGB pixel stream to encoders.
20
21The encoder modules encode the received RGB pixel stream to a video output like
22HDMI, MIPI DPI, etc.
23
24Video Ports
25-----------
26
27The DSS Core and the encoders have video port outputs. The structure of the
28video ports is described in Documentation/devicetree/bindings/graph.txt,
29and the properties for the ports and endpoints for each encoder are
30described in the SoC's DSS binding documentation.
31
32The video ports are used to describe the connections to external hardware, like
33panels or external encoders.
34
35Aliases
36-------
37
38The board dts file may define aliases for displays to assign "displayX" style
39name for each display. If no aliases are defined, a semi-random number is used
40for the display.
41
42Example
43-------
44
45A shortened example of the DSS description for OMAP4, with non-relevant parts
46removed, defined in omap4.dtsi:
47
48dss: 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
83A shortened example of the board description for OMAP4 Panda board, defined in
84omap4-panda.dts.
85
86The Panda board has a DVI and a HDMI connector, and the board contains a TFP410
87chip (MIPI DPI to DVI encoder) and a TPD12S015 chip (HDMI ESD protection & level
88shifter). The video pipelines for the connectors are formed as follows:
89
90DSS Core --(MIPI DPI)--> TFP410 --(DVI)--> DVI Connector
91OMAP 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};
212