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