[转] MTK8788[android 9.0]汇顶GT9XX TP触摸屏驱动流程分析

转自: https://blog.csdn.net/MrDongShiYi/article/details/100709633?utm_medium=distribute.pc_relevant.none-task-blog-2%7Edefault%7ECTRLIST%7Edefault-1.no_search_link&depth_1-utm_source=distribute.pc_relevant.none-task-blog-2%7Edefault%7ECTRLIST%7Edefault-1.no_search_link

TP 相关引脚DTS中的定义我们这个项目TP复位引脚是GPIO158,中断引脚是GPIO1，由下图原理图知道我们的TP挂载在I2c0上，3.3v的供电电压是有PMIC 2.8V供电电压通过i2c电平转换过来的，所以供电电压需要配置pmic 2.8v

/* TOUCH start */
&touch {
    tpd-resolution = <800 1280>;//分辨率
    use-tpd-button = <0>;//如果TP有待按键。则定义值为1
    tpd-key-num = <3>;//按键的数量
    tpd-key-local= <139 172 158 0>;//按键的编码，一般为KEY_MENU,KEY_HOMEPAGE，KEY_BACK的键值
    tpd-key-dim-local = <90 883 100 40 230 883 100 40 370 883 100 40 0 0 0 0>;//按键的布局信息，包含按键的宽度，高度，中心点的坐标
    tpd-max-touch-num = <5>;//支持的最大触摸点数
    tpd-filter-enable = <0>; //fae suggest this change to improve effect
    tpd-filter-pixel-density = <146>;
    tpd-filter-custom-prameters = <0 0 0 0 0 0 0 0 0 0 0 0>;
    tpd-filter-custom-speed = <0 0 0>;
    pinctrl-names = "default", "state_eint_as_int", "state_eint_output0", "state_eint_output1",
        "state_rst_output0", "state_rst_output1";
    pinctrl-0 = <&ctp_pins_default>;
    pinctrl-1 = <&ctp_pins_eint_as_int>;
    pinctrl-2 = <&ctp_pins_eint_output0>;
    pinctrl-3 = <&ctp_pins_eint_output1>;
    pinctrl-4 = <&ctp_pins_rst_output0>;
    pinctrl-5 = <&ctp_pins_rst_output1>;
    status = "okay";
};
&pio {
    ctp_pins_default: eint0default {
    };
    ctp_pins_eint_as_int: eint@0 {
        pins_cmd_dat {
            pins = <PINMUX_GPIO1__FUNC_GPIO1>;
            slew-rate = <0>;
            bias-disable;
        };
    };
    ctp_pins_eint_output0: eintoutput0 {
        pins_cmd_dat {
            pins = <PINMUX_GPIO1__FUNC_GPIO1>;
            slew-rate = <1>;
            output-low;
        };
    };
    ctp_pins_eint_output1: eintoutput1 {
        pins_cmd_dat {
            pins = <PINMUX_GPIO1__FUNC_GPIO1>;
            slew-rate = <1>;
            output-high;
        };
    };
    ctp_pins_rst_output0: rstoutput0 {
        pins_cmd_dat {
            pins = <PINMUX_GPIO158__FUNC_GPIO158>;
            slew-rate = <1>;
            output-low;
        };
    };
    ctp_pins_rst_output1: rstoutput1 {
        pins_cmd_dat {
            pins = <PINMUX_GPIO158__FUNC_GPIO158>;
            slew-rate = <1>;
            output-high;
        };
    };
};
/* TOUCH end */
&i2c0 {
        status = "okay";

        goodix_touch@5e {
                compatible = "mediatek,goodix_touch"; //用于匹配GT9xx这个TP驱动

                reg = <0x5e>;//GT9xx I2c的地址
                interrupt-parent = <&pio>; //中断脚
                interrupts = <1 IRQ_TYPE_EDGE_RISING 1 0>;//中断模式是上升沿触发
                //vtouch-supply = <&mt_pmic_vldo28_ldo_reg>; //原生MTK节点TP 2.8V PMIC供电
                reg-tp-supply = <&mt_pmic_vldo28_ldo_reg>; //由于我们代码上修改了TP 2.8V PMIC供电节点获取是以reg-tp-supply这个字符获取的原生的是由vtouch-supply这个获取的
                rst-gpio = <&pio 158 0>;//TP的复位引脚
                int-gpio = <&pio 1 0>;//TP的中断引脚

                status = "okay";
            };
    }

驱动流程表：