> ## Documentation Index > Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt > Use this file to discover all available pages before exploring further. # 配置 pinctrl 驱动 Qualcomm® Linux 内核中的 Pinctrl 子系统管理和配置用于通用输入/输出（GPIO）、内部集成电路（I2C）、串行外设接口（SPI）以及其他硬件接口的引脚。 Pinctrl 配置（例如**引脚复用（pin muxing）**和**引脚分组（pin groupings）**）在特定于设备的 pinctrl 驱动中管理，这些驱动列出了所有可用的引脚和功能。 例如，QCS6490 对应的驱动位于 `kernel-src/drivers/pinctrl/qcom/pinctrl-sc7280.c` 文件中。 有关其他 Qualcomm SoC pinctrl 驱动的更多信息，请参阅 [Pinctrl Drivers](https://github.com/torvalds/linux/tree/master/drivers/pinctrl/qcom)。 以下是 pinctrl 数据对象： **表：Pinctrl 数据对象** | **变量** | **描述** | | :-------------------------------------------------: | :-----------------: | | static const struct pinctrl\_pin\_desc sc7280\_pins | 枚举所有引脚及其名称 | | static const struct msm\_pingroup sc7280\_groups | 定义该组 GPIO 引脚可用的复用功能 | | enum sc7280\_functions | 以枚举值形式列出所有可用功能 | \ 有关 QCS6490 相应 SoC pinctrl 绑定文档中支持功能的更多信息，请参阅 [pinctrl 绑定文档](https://www.kernel.org/doc/Documentation/devicetree/bindings/pinctrl/qcom%2Csc7280-pinctrl.yaml)。 **功能选择** 对于 `sc7280_functions` 数据对象，一个或多个 GPIO 引脚作为一个功能使用，必须注册到设备树并传递给正确的设备节点。 在系统启动期间，内核 pinctrl 基础设施会注册这些功能。 以下示例展示了内核配置基础设施： ```text theme={null} tlmm: pinctrl@f100000 { compatible = "qcom,sc7280-pinctrl"; : : : : qup_spi0_data_clk: qup-spi0-data-clk-state { pins = "gpio0", "gpio1", "gpio2"; function = "qup00"; }; qup_spi0_cs: qup-spi0-cs-state { pins = "gpio3"; function = "qup00"; }; qup_spi1_data_clk: qup-spi1-data-clk-state { pins = "gpio4", "gpio5", "gpio6"; function = "qup01"; }; qup_spi1_cs: qup-spi1-cs-state { pins = "gpio7"; function = "qup01"; }; : : : : }; spi0: spi@980000 { compatible = "qcom,geni-spi"; reg = <0 0x00980000 0 0x4000>; clocks = <&gcc GCC_QUPV3_WRAP0_S0_CLK>; clock-names = "se"; pinctrl-names = "default"; pinctrl-0 = <&qup_spi0_data_clk>, <&qup_spi0_cs>; interrupts = ; #address-cells = <1>; #size-cells = <0>; power-domains = <&rpmhpd SC7280_CX>; operating-points-v2 = <&qup_opp_table>; interconnects = <&clk_virt MASTER_QUP_CORE_0 0 &clk_virt SLAVE_QUP_CORE_0 0>, <&gem_noc MASTER_APPSS_PROC 0 &cnoc2 SLAVE_QUP_0 0>; interconnect-names = "qup-core", "qup-config"; dmas = <&gpi_dma0 0 0 QCOM_GPI_SPI>, <&gpi_dma0 1 0 QCOM_GPI_SPI>; dma-names = "tx", "rx"; status = "disabled"; }; ``` ## 配置 GPIO 使用 GPIO 引脚配置需要以下两项设置。这些设置定义了 GPIO 引脚状态，并使这些引脚可用于任何输入/输出活动。 * 复用（Mux）：复用设置需要从特定于 SoC 的 pinctrl 驱动中可用功能集里选择所映射的功能名称。有关 pinctrl 的更多信息，请参阅 [Pinctrl 配置](https://docs.qualcomm.com/doc/80-80021-3/topic/pinctrl-configuration.html?product=895724676033554725\&facet=Kernel\&version=2.0-rc2#pinctrl-configuration)。 * 配置（Configuration）：配置方面需要设置驱动强度（drive strength）和偏置（bias）属性。 以下示例展示了如何通过以下步骤用这两项设置定义 GPIO 引脚： 1. 在设备树中定义引脚配置： ```text theme={null} bt_en: bt-en-state { pins = "gpio85"; function = "gpio"; output-low; bias-disable; }; ``` 2. 在设备树中配置设备节点或知识产权（IP）模块： ```text theme={null} bluetooth: bluetooth { compatible = "qcom,wcn6750-bt"; pinctrl-names = "default"; pinctrl-0 = <&bt_en>, <&sw_ctrl>; enable-gpios = <&tlmm 85 GPIO_ACTIVE_HIGH>; swctrl-gpios = <&tlmm 86 GPIO_ACTIVE_HIGH>; vddaon-supply = <&vreg_s7b_0p9>; vddbtcxmx-supply = <&vreg_s7b_0p9>; vddrfacmn-supply = <&vreg_s7b_0p9>; vddrfa0p8-supply = <&vreg_s7b_0p9>; vddrfa1p7-supply = <&vreg_s1b_1p8>; vddrfa1p2-supply = <&vreg_s8b_1p2>; vddrfa2p2-supply = <&vreg_s1c_2p2>; vddasd-supply = <&vreg_l11c_2p8>; max-speed = <3200000>; ``` 3. 驱动代码必须使用通用 API 在 pinctrl 配置中选择并注册其 GPIO 配置。以下是可用 API 的示例： > ```text theme={null} > devm_gpiod_get_optional(&serdev->dev, "enable", GPIOD_OUT_LOW); > > /** > * devm_gpiod_get_optional - Resource-managed gpiod_get_optional() > * @dev: GPIO consumer > * @con_id: function within the GPIO consumer > * @flags: optional GPIO initialization flags > * > * Managed gpiod_get_optional(). GPIO descriptors returned from this function > * are automatically disposed on driver detach. See gpiod_get_optional() for > * detailed information about behavior and return values. */ > > gpiod_set_value_cansleep(qcadev->bt_en, 0); > > /** > * gpiod_set_value_cansleep() - assign a gpio's value > * @desc: gpio whose value will be assigned > * @value: value to assign > * > * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into > * account > * > * This function is to be called from contexts that can sleep. > */ > ``` **GPIO 作为中断请求（IRQ）** 要将 GPIO 设置为 IRQ，请按以下步骤操作： 1. 在 DTS 文件中配置 GPIO 引脚： 1. 设置 GPIO 引脚的属性和功能。 2. 使用以下配置将引脚设置为使用 GPIO 55 实现 `qup_se_l3()` 功能： ```text theme={null} qupv3_se3_rx: qupv3-se3-rx-state { pins = "gpio55"; function = "qup03"; // To be taken from available from functions. drive-strength = <2>; bias-disable; }; ``` 2. 为要将 GPIO 设置为 IRQ 的设备节点创建类似于前述配置的 DT 条目。在以下示例中，GPIO55 被配置为 IRQ，其父级为顶层模式多路复用器（TLMM），电平设置为高。 ```text theme={null} interrupts-extended = <&tlmm 55 IRQ_TYPE_LEVEL_HIGH>; ``` 3. 驱动必须读取该值，并使用 `request_irq` API（指定中断服务寄存器（ISR）和 IRQ 标志）将其作为中断注册到通用中断控制器（GIC）。 ```text theme={null} irq_no = platform_get_irq(pdev, 1); ``` ## 配置 GPIO 以生成时钟或脉宽调制 将任何具有 `GP_CLK` 备用功能的 GPIO 配置为时钟或脉宽调制（PWM）输出。 以下步骤适用于 QCS6490 SoC。 有关如何查找具有 `GP_CLK` 功能的 GPIO 的更多信息，请参阅[引脚描述](https://docs.qualcomm.com/bundle/publicresource/topics/80-23889-1/pin-definitions.html#sub\$pin-descriptions:~:text=and%20available%20configurations.-,Table%20%3A%20Pin%20descriptions%20%E2%80%93%20general%2Dpurpose%20input/output%20ports,-Pad%20number)。 1. 在 `kernel/arch/arm64/boot/dts/qcom/sc7280.dtsi` 文件中添加 GPIO 配置节点。 > ```text theme={null} > +gpio_pwm_default: gpio_pwm_default { > + mux { > + pins = "gpio42"; > + function = "gcc_gp1"; // search "gcc_gp" in "kernel/drivers/pinctrl/qcom/pinctrl-sc7280.c", From this we can find out which GPIO's has GP_CLK functionality > + }; > + > + config { > + pins = "gpio42"; > + bias-disable; /* No PULL */ > + drive-strength = <8>; /* 2 MA */ > + }; > +}; > ``` 2. 在 `kernel/arch/arm64/boot/dts/qcom/sc7280.dtsi` 文件中定义设备树节点。 ```text theme={null} +beeper: beeper { + compatible = "gpio-beeper"; + pinctrl-names = "default"; + pinctrl-0 = <&gpio_pwm_default>; + clocks = <&clock_gcc GCC_GP1_CLK>; //clock_gcc is gcc clk device node, GCC_GP1_CLK index which defined in "kernel/include/dt-bindings/clock/qcom,gcc-sc7280.h" + clock-names = "gpio-pwm-clk"; +}; ``` 3. 在设备驱动中添加以下代码： ```text theme={null} +#include +#include ... + struct clk *pclk; + struct rcg_clk *gp1_rcg_clk; + int ret; + + pclk = devm_clk_get(&pdev->dev, "gpio-pwm-clk"); + ret = clk_set_rate(pclk, 50000000); // please check the freq table in kernel/drivers/clk/qcom/gcc-sc7280.c, the freq can be found in the freq table of GCC_GP1_CLK. + if (ret) + printk("clk set rate fail, ret = %d\n", ret); + + ret = clk_prepare_enable(pclk); // By default this will enable clock as PWM with 50% duty cycle. + if (ret) + printk("%s: clk_prepare error!!!\n", __func__); + else + printk("%s: clk_prepare success!\n", __func__); + ``` 4. 如果不使用时钟或 PWM，请调用 `clk_disable_unprepare()` 禁用时钟以节省功耗。**注意**：请确保在调用 `clk_disable_unprepare()` 之前先调用 `clk_prepare_enable()`。 5. 要生成所需的占空比，请在 `clk_prepare_enable` API 之后调用 `clk_set_duty_cycle()` API。 ## 从用户空间配置 GPIO 从用户空间使用 `libgpiod` 库控制 GPIO，以获得更好的性能。 1. 要在主机上编译并推送 `libgpiod` 库，请执行以下操作： 1. 要安装 Arm®（Arm64）工具链，请运行以下命令： ```text theme={null} sudo apt install gcc-aarch64-linux-gnu ``` ```text theme={null} sudo apt install binutils-aarch64-linux-gnu ``` 2. 要从 [libgpiod 1.6.4.tar.xz](https://www.kernel.org/pub/software/libs/libgpiod/libgpiod-1.6.4.tar.xz) 下载并解压 libgpiod 源代码，请运行以下命令： ```text theme={null} wget https://www.kernel.org/pub/software/libs/libgpiod/libgpiod-1.6.4.tar.xz ``` ```text theme={null} tar xvf libgpiod-1.6.4.tar.xz ``` ```text theme={null} cd libgpiod-1.6.4 ``` 3. 要为静态链接配置源代码，请运行以下命令： ```text theme={null} ./configure --enable-tools=yes --build x86_64-pc-linux-gnu --host aarch64-linux-gnu CFLAGS="-static -static-libgcc -Wl,-static,--start-group,/usr/lib/gcc-cross/aarch64-linux-gnu/7.5.0/libgcc.a,/usr/lib/gcc-cross/aarch64-linux-gnu/7.5.0/libgcc_eh.a,/usr/aarch64-linux-gnu/lib/libc.a,--end-group" ``` 4. 要编译该库，请运行以下命令： ```text theme={null} make ``` **注意**：编译会创建链接的二进制文件。 5. 要构建静态链接的二进制文件，请运行以下命令： ```text theme={null} aarch64-linux-gnu-gcc -static -o tools/gpiodetect tools/gpiodetect.o tools/tools-common.o -Wl,-L/libgpiod-1.6.4/lib/.libs,-lgpiod,-lpthread,-static ``` ```text theme={null} aarch64-linux-gnu-gcc -static -o tools/gpioget tools/gpioget.o tools/tools-common.o -Wl,-L/libgpiod-1.6.4/lib/.libs,-lgpiod,-lpthread,-static ``` ```text theme={null} aarch64-linux-gnu-gcc -static -o tools/gpioset tools/gpioset.o tools/tools-common.o -Wl,-L/libgpiod-1.6.4/lib/.libs,-lgpiod,-lpthread,-static ``` ```text theme={null} aarch64-linux-gnu-gcc -static -o tools/gpiofind tools/gpiofind.o tools/tools-common.o -Wl,-L/libgpiod-1.6.4/lib/.libs,-lgpiod,-lpthread,-static ``` ```text theme={null} aarch64-linux-gnu-gcc -static -o tools/gpioinfo tools/gpioinfo.o tools/tools-common.o -Wl,-L/libgpiod-1.6.4/lib/.libs,-lgpiod,-lpthread,-static ``` ```text theme={null} aarch64-linux-gnu-gcc -static -o tools/gpiomon tools/gpiomon.o tools/tools-common.o -Wl,-L/libgpiod-1.6.4/lib/.libs,-lgpiod,-lpthread,-static ``` 2. 编译完成后，运行 `scp` 命令将二进制文件推送到您的设备。例如： ```text theme={null} scp gpioinfo root@:/path/to/directory/on/device ``` 将二进制文件推送到设备后，在设备上运行以下命令与 GPIO 交互： 1. 使用 `gpiodetect` 和 `gpioinfo` 命令列出 GPIO 芯片和线路。以下示例展示了 GPIO 芯片信息： ```text theme={null} sh-5.2# ./gpiodetect gpiochip0 [c440000.spmi:pmic@8:pinctrl@c00] (12 lines) gpiochip1 [c440000.spmi:pmic@1:gpio@8800] (10 lines) gpiochip2 [c440000.spmi:pmic@2:gpio@8800] (9 lines) gpiochip3 [c440000.spmi:pmic@0:gpio@b000] (4 lines) gpiochip4 [f100000.pinctrl] (176 lines) gpiochip5 [33c0000.pinctrl] (15 lines) ``` 以下示例展示了 GPIO 线路： ```text theme={null} sh-5.2# ./gpioinfo gpiochip5 gpiochip5 - 15 lines: line 0: unnamed unused input active-high line 1: unnamed unused input active-high line 2: unnamed unused input active-high line 3: unnamed unused input active-high line 4: unnamed unused input active-high line 5: unnamed unused input active-high line 6: unnamed unused input active-high line 7: unnamed unused input active-high line 8: unnamed unused input active-high line 9: unnamed unused input active-high line 10: unnamed unused input active-high line 11: unnamed unused input active-high line 12: unnamed unused input active-high line 13: unnamed unused input active-high line 14: unnamed unused input active-high ``` 2. 使用 `gpioset` 命令设置 GPIO 值。例如，要设置 `gpiochip4` 上的 `GPIO line 0`，请执行以下操作： ```text theme={null} sh-5.2# ./gpioset gpiochip4 0=1 sh-5.2# ./gpioinfo gpiochip4 gpiochip4 - 176 lines: line 0: unnamed unused output active-high line 1: unnamed unused input active-high ``` 3. 使用 `gpioget` 命令读取 GPIO 值。例如，要读取 `gpiochip4` 上 `GPIO line 0` 的值，请执行以下操作： ```text theme={null} sh-5.2# ./gpioget gpiochip4 0 1 sh-5.2# ./gpioinfo gpiochip4 gpiochip4 - 176 lines: line 0: unnamed unused input active-high line 1: unnamed unused input active-high ```