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硬件:imx6 ads7846电阻屏

系统:android7.1 LCD显示屏的坐标原点为左上角(800,600),触摸屏的坐标原点为右下角(xmin,ymin)

1.通过驱动打印原始的坐标值

static void ads7846_report_state(struct ads7846 *ts)

获取坐标原点和最大值分别为(xmin,ymin)(xmax,ymax) u16 ymin=480,ymax=3520; u16 xmin=270,xmax=3750;

2.坐标变换,经过坐标变换使LCD的坐标原点和触摸屏的坐标原点重合

#define LCD_X 800#define LCD_Y 600    x = LCD_X*(x-xmin)/(xmax-xmin);    y = LCD_Y-LCD_Y*(y-ymin)/(ymax-ymin);    input_report_abs(input, ABS_X, x);    input_report_abs(input, ABS_Y, y);

3.配置文件

getevent获取触摸屏的input device name

add device 3: /dev/input/event1 name: “ADS7846_Touchscreen” 增加配置文件 device/fsl/imx6/imx6.mk device/fsl/common/input/eGalax_Touch_Screen.idc:system/usr/idc/ADS7846_Touchscreen.idc 内容为 touch.deviceType = touchScreen touch.orientationAware = 1

touch.size.calibration = none

touch.orientation.calibration = none

５.dtsi

+&ecspi2 {
   +       fsl,spi-num-chipselects = <1>;+       cs-gpios = <&gpio2 26 GPIO_ACTIVE_LOW>;+       pinctrl-names = "default";+       pinctrl-0 = <&pinctrl_ecspi2>;+       status = "okay";++       tsc2046: tsc2046@0 {
   +               pinctrl-names = "default";+               pinctrl-0 = <&tsc2046_irq_pins>;+               status = "okay";+               spi-max-frequency = <50000>;+               reg = <0>;+               compatible = "ti,tsc2046";+               interrupt-parent = <&gpio4>;+               interrupts = <10 2>;    +               pendown-gpio = <&gpio4 10 0>;+               irq = <&gpio4 10 GPIO_ACTIVE_LOW>;+++               ti,x-min = /bits/ 16 <0>;+               ti,x-max = /bits/ 16 <800>;+               ti,y-min = /bits/ 16 <0>;+               ti,y-max = /bits/ 16 <600>;+               ti,x-plate-ohms = /bits/ 16 <500>;+               ti,y-plate-ohms = /bits/ 16 <400>;+               ti,pressure-max = /bits/ 16 <255>; +       ++       };+};+               pinctrl_ecspi2: ecspi2grp {
   +                       fsl,pins = <+                               MX6QDL_PAD_EIM_RW__GPIO2_IO26           0x100b1                         +                               MX6QDL_PAD_EIM_CS1__ECSPI2_MOSI         0x100b1+                               MX6QDL_PAD_EIM_OE__ECSPI2_MISO          0x100b1+                               MX6QDL_PAD_EIM_CS0__ECSPI2_SCLK         0x100b1+                       >;+               };++               tsc2046_irq_pins: tsc2046_irq_pinsgrp {
   +                       fsl,pins = <+                               MX6QDL_PAD_KEY_COL2__GPIO4_IO10         0x1b0b1+                       +                       >;+               };

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