高通 - GPIO驱动调试

一、概述

控制gpio一般有二种方式，第一种是gpio的控制方式，第二种通过pinctrl配置。

二、GPIO方式

1、 DTS设备节点中添加gpio

device_node {
             ...
             gpio_name = <&tlmm XX 0>;  
             ...
     }

2、驱动代码
文件路径：android\kernel\msm-3.18\drivers\gpio\ gpiolib.c

int gpio_XXX = of_get_named_gpio(dev->of_node,"gpio_name", 0);
	 gpio_request(gpio_99, "gpio_name");        //通过gpio号申请gpio
	 gpio_direction_output(gpio_XX, 1);         //设置gpio_XX输出，初始值为1
	 gpio_set_value(gpio_XX, 0);                //设置gpio_XX值为0
	 gpio_free(gpio_XX);                        //gpio_XX不再使用后应当释放

三、Pinctrl控制方式

1、DTS代码
平台pinctrl节点下添加如下子节点

gpio_group {
   gpio_active: gpio_active {
          mux {
                   pins = "gpio99", "gpio98";    //复用引脚99和98
                   functions = "gpio";            //引脚功能配置为普通gpio
           };
           config {
                   pins = "gpio99", "gpio98";
                   drive-strength = <8>;    //最大电流限制为8mA
                   bias-pull-up;                //配置上拉
                   output-high;                //输出高电平
            };
   };
   gpio_sleep: gpio_sleep {
          mux {
                   pins = "gpio99", "gpio98";    //复用引脚99和98
                   functions = "gpio";            //引脚功能配置为普通gpio
           };
           config {
                   pins = "gpio99", "gpio98";
                   drive-strength = <2>;    //最大电流限制为2mA
                   bias-no-pull;                //不上拉也不下拉
                   output-low;                //输出低电平
            }; 
};

2、设备节点中引用pinctrl

 device_node {
      ...
             pinctrl-names = "gpio_active", "gpio_sleep";    //分别对用pinctrl-0和pinctrl-1
             pinctrl-0 = <&gpio_active>;                               //引用
             pinctrl-1 = <&gpio_sleep>;                                //引用
             ...
 };

3、内核驱动代码

struct pinctrl *pinctrl = devm_pinctrl_get(device);    //获取device对应节点下的pinctrl
struct pinctrl_state = pinctrl_lookup_state(pinctrl, "gpio_active");    //通过pinctrl名获取pinctrl对应状态
pinctrl_select_state(pinctrl, pinctrl_state);        //设置pinctrl的状态为'gpio_active
devm_pinctrl_put(pinctrl);         					 //使用完了释放资源

四、 gpio debug

方法1:

msm8953_64:/sys/kernel/debug # cat gpio | grep gpio16
 					gpio16  : in  2 2mA pull down

方法2:

获取gpio状态
        cd /sys/kernel/debug/
        cat gpio
 操作gpio（以gpio99为例）
        cd /sys/class/gpio/
        echo 99 > export
        cd gpio99
        echo in/out > direction    //设置gpio输入或输出
        cat direction                    //获取gpio输入输出状态
        echo 'value' > value        //设置gpio寄存器值
        cat value                        //获取gpio寄存器的值

方法3:

TLMM_GPIO_CFGn 0x1000000 + 0x1000 * (n)
TLMM_GPIO_IN_OUTn 0x1000004 + 0x1000 * (n)
TLMM_GPIO_INTR_CFGn 0x1000008 + 0x1000 * (n)
TLMM_GPIO_INTR_STATUSn 0x100000C + 0x1000 * (n)
Example:To read GPIO 19 config registers
#/system/bin/r 0x1013000
#/system/bin/r 0x1013004
#/system/bin/r 0x1013008
#/system/bin/r 0x101300C 

五、Regulator 配置

msm8953-regulator.dtsi

rpm-regulator-ldoa10 {
status = "okay";
pm8953_l10: regulator-l10 {
	regulator-min-microvolt = <2850000>;
	regulator-max-microvolt = <2850000>;
	qcom,init-voltage = <2850000>;
	status = "okay";
	};
};

msm8953-sc826-evk.dtsi

&i2c_3 { /* BLSP1 QUP3 */
           status = "okay";
            goodix@5d {
                     compatible = "goodix,gt9xx";
                     reg = <0x5d>;
                    vdd-supply = <&pm8953_l10>;
                     vdd_ld-supply = <&pm8953_l17>;

static int goodix_power_init(struct goodix_ts_data *ts)
{
	ts->vdd = regulator_get(&ts->client->dev, "vdd");
	    if (IS_ERR(ts->vdd)) {
	        ret = PTR_ERR(ts->vdd);
}

regulator_set_voltage(ts->vdd, GOODIX_VTG_MIN_UV,
                       GOODIX_VTG_MAX_UV);//设置电压
regulator_enable(ts->vdd);//使能电压
regulator_disable(ts->vdd); //关闭电压

5.1 Regulator debug

msm8953_64:/sys/kernel/debug/regulator/pm8953_l8 # ls

7824900.sdhci-vdd consumers force_disable open_count   pm8953_l8 voltage
	bypass_count      enable    mode          optimum_mode use_count

msm8953_64:/sys/class/regulator # ls

regulator.0  regulator.16 regulator.23 regulator.30 regulator.38 regulator.45
		regulator.1  regulator.17 regulator.24 regulator.31 regulator.39 regulator.46
		regulator.10 regulator.18 regulator.25 regulator.32 regulator.4  regulator.47
		regulator.11 regulator.19 regulator.26 regulator.33 regulator.40 regulator.5
		regulator.12 regulator.2  regulator.27 regulator.34 regulator.41 regulator.6
		regulator.13 regulator.20 regulator.28 regulator.35 regulator.42 regulator.7
		regulator.14 regulator.21 regulator.29 regulator.36 regulator.43 regulator.8
		regulator.15 regulator.22 regulator.3  regulator.37 regulator.44 regulator.9

msm8953_64:/sys/class/regulator # cd regulator.20
msm8953_64:/sys/class/regulator/regulator.20 # ls

4080000.qcom,mss-vdd_pll max_microvolts num_users subsystem             type
		78000.ssphy-vdda18       microvolts     opmode    suspend_disk_state    uevent
		79000.qusb-vdda18        min_microvolts power     suspend_mem_state
		device                   name           state     suspend_standby_state

msm8953_64:/sys/class/regulator/regulator.20 # cat name
pm8953_l7
msm8953_64:/sys/class/regulator/regulator.20 # cat state
enabled