arch/arm/boot/dts/overlays/ads7846-overlay.dts

   1 /*
   2  * Generic Device Tree overlay for the ADS7846 touch controller
   3  *
   4  */
   5
   6 /dts-v1/;
   7 /plugin/;
   8
   9 / {
  10         compatible = "brcm,bcm2835";
  11
  12         fragment@0 {
  13                 target = <&spi0>;
  14                 __overlay__ {
  15                         status = "okay";
  16                 };
  17         };
  18
  19         fragment@1 {
  20                 target = <&spidev0>;
  21                 __overlay__ {
  22                         status = "disabled";
  23                 };
  24         };
  25
  26         fragment@2 {
  27                 target = <&spidev1>;
  28                 __overlay__ {
  29                         status = "disabled";
  30                 };
  31         };
  32
  33         fragment@3 {
  34                 target = <&gpio>;
  35                 __overlay__ {
  36                         ads7846_pins: ads7846_pins {
  37                                 brcm,pins = <255>; /* illegal default value */
  38                                 brcm,function = <0>; /* in */
  39                                 brcm,pull = <0>; /* none */
  40                         };
  41                 };
  42         };
  43
  44         fragment@4 {
  45                 target = <&spi0>;
  46                 __overlay__ {
  47                         /* needed to avoid dtc warning */
  48                         #address-cells = <1>;
  49                         #size-cells = <0>;
  50
  51                         ads7846: ads7846@1 {
  52                                 compatible = "ti,ads7846";
  53                                 reg = <1>;
  54                                 pinctrl-names = "default";
  55                                 pinctrl-0 = <&ads7846_pins>;
  56
  57                                 spi-max-frequency = <2000000>;
  58                                 interrupts = <255 2>; /* high-to-low edge triggered */
  59                                 interrupt-parent = <&gpio>;
  60                                 pendown-gpio = <&gpio 255 0>;
  61
  62                                 /* driver defaults */
  63                                 ti,x-min = /bits/ 16 <0>;
  64                                 ti,y-min = /bits/ 16 <0>;
  65                                 ti,x-max = /bits/ 16 <0x0FFF>;
  66                                 ti,y-max = /bits/ 16 <0x0FFF>;
  67                                 ti,pressure-min = /bits/ 16 <0>;
  68                                 ti,pressure-max = /bits/ 16 <0xFFFF>;
  69                                 ti,x-plate-ohms = /bits/ 16 <400>;
  70                         };
  71                 };
  72         };
  73         __overrides__ {
  74                 cs =     <&ads7846>,"reg:0";
  75                 speed =  <&ads7846>,"spi-max-frequency:0";
  76                 penirq = <&ads7846_pins>,"brcm,pins:0", /* REQUIRED */
  77                          <&ads7846>,"interrupts:0",
  78                          <&ads7846>,"pendown-gpio:4";
  79                 penirq_pull = <&ads7846_pins>,"brcm,pull:0";
  80                 swapxy = <&ads7846>,"ti,swap-xy?";
  81                 xmin =   <&ads7846>,"ti,x-min;0";
  82                 ymin =   <&ads7846>,"ti,y-min;0";
  83                 xmax =   <&ads7846>,"ti,x-max;0";
  84                 ymax =   <&ads7846>,"ti,y-max;0";
  85                 pmin =   <&ads7846>,"ti,pressure-min;0";
  86                 pmax =   <&ads7846>,"ti,pressure-max;0";
  87                 xohms =  <&ads7846>,"ti,x-plate-ohms;0";
  88         };
  89 };