OpenHarmony GPIO应用开发-LED_openharmony stm32 gpio驱动代码

学习于：
https://docs.openharmony.cn/pages/v5.0/zh-cn/device-dev/driver/driver-platform-gpio-develop.md
https://docs.openharmony.cn/pages/v5.0/zh-cn/device-dev/driver/driver-platform-gpio-des.md
通过OpenHarmony官方文档指导可获知：芯片厂商应当按照系统的平台驱动接口实现GPIO控制器驱动后，设备开发人员就可以按照系统GPIO的HDI接口使用GPIO，具体接口函数有：

其中函数参数gpioName指定IO口名，gpio指定IO口的ID，参数具体值由芯片厂商在.hcs配置文件中描述，如海思Hi3516中GPIO控制器驱动的描述：

Hi3516 GPIO控制器驱动自定义属性的描述：

其中属性groupNum指定Hi3516共有12组IO口，bitNum指定每组有8个IO口，由0 ~ 95数值分别表示96个IO，如GPIO2_3，则由数值19表示(2*8 + 3 = 19)。
属性gpioCustomName指定IO口的名称，依此名称可通过函数GpioGetByName获取IO口对应的ID。

接下来通过应用GPIO实现LED驱动：
开发板LED原理图


通过原理图可发现有: GPIO2_3 GPIO3_4 GPIO5_1控制LED的工作。

简单的LED驱动
在上篇简单的HDF驱动驱动源码基础上加入控制一个LED的代码，具体drivers/hdf_core/adapter/khdf/liteos/platform/src/myTestDriver.c驱动源码内容如下：

#include #include #include #include  // GPIO驱动调用接口static int idGpio = 0;static int32_t myDispatch( struct HdfDeviceIoClient *client, int id, struct HdfSBuf *data, struct HdfSBuf *reply){ HDF_LOGD(\"### in %s : %d\\n\", __func__, id); GpioWrite(idGpio, id%2); //配置GPIO输出高低电平 return HDF_SUCCESS;}int32_t myBind(struct HdfDeviceObject *obj){ static struct IDeviceIoService testService = { .Dispatch = myDispatch, }; obj->service = &testService; HDF_LOGD(\"#### in %s\\n\", __func__); idGpio = GpioGetByName(\"GPIO2_3\"); //获取GPIO的ID GpioSetDir(idGpio, GPIO_DIR_OUT); //配置GPIO作输出用途 return HDF_SUCCESS;}int32_t myInit(struct HdfDeviceObject *obj){ HDF_LOGD(\"#### in %s\\n\", __func__); return HDF_SUCCESS;}void myRelease(struct HdfDeviceObject *obj){ HDF_LOGD(\"#### in %s\\n\", __func__);}struct HdfDriverEntry myTestEntry = { .Bind = myBind, .Init = myInit, .Release = myRelease, .moduleName = \"myTestDriver\", .moduleVersion = 1};HDF_INIT(myTestEntry);

沿用上篇里的应用程序，当应用程序执行起来后，开发板的LED会在GPIO输出高电平时亮，低电平时熄。

硬件资源分离与可重用的LED驱动
按照OpenHarmony文档指导，硬件相关的资源应当在.hcs配置文件中描述。这里三个LED分别作为一个设备进行描述 ：

然后在vendor/hisilicon/hispark_taurus/hdf_config/目录下创建myLight文件夹，并在文件夹里创建myLight.hcs配置文件，描述设备自定义的属性：

每个节点通过match_attr与设备节点的deviceMatchAttr进行匹配，相同值表示此节点资源由对应的设备使用。 gpioName自定义属性向LED驱动提供LED设备的控制IO。
然后修改vendor/hisilicon/hispark_taurus/hdf_config/hdf.hcs配置文件，增加myLight.hcs文件的使用：

驱动源文件myTestDriver.c代码修改为：

#include #include #include #include #include #include struct myLightService { struct IDeviceIoService service; int idGpio; const char *gpioName;};static int32_t myDispatch( struct HdfDeviceIoClient *client, int id, struct HdfSBuf *data, struct HdfSBuf *reply){ struct HdfDeviceObject *obj = client->device; struct myLightService *srv = (struct myLightService *)(obj->service); HDF_LOGD(\"### in %s, %s %d\\n\", __func__, srv->gpioName, id); GpioWrite(srv->idGpio, !!id); return HDF_SUCCESS;}int32_t myBind(struct HdfDeviceObject *obj){ struct myLightService *srv = NULL; struct DeviceResourceIface *dr = DeviceResourceGetIfaceInstance(HDF_CONFIG_SOURCE); srv = OsalMemCalloc(sizeof(struct myLightService)); dr->GetString(obj->property, \"gpioName\", &srv->gpioName, NULL); srv->service.Dispatch = myDispatch; srv->idGpio = GpioGetByName(srv->gpioName); GpioSetDir(srv->idGpio, GPIO_DIR_OUT); obj->service = &srv->service; return HDF_SUCCESS;}int32_t myInit(struct HdfDeviceObject *obj){ return HDF_SUCCESS;}void myRelease(struct HdfDeviceObject *obj){ struct myLightService *srv = (struct myLightService *)(obj->service); OsalMemFree(srv);}struct HdfDriverEntry myTestEntry = { .Bind = myBind, .Init = myInit, .Release = myRelease, .moduleName = \"myTestDriver\", .moduleVersion = 1};HDF_INIT(myTestEntry);

在applications/sample/camera/myhello/mytest.c代码修改为：

#include #include #include #include #include \"hdf_log.h\"#include \"hdf_sbuf.h\"#include \"hdf_io_service_if.h\"int main(int argc, char *argv[]){ if (3 != argc) { printf(\"usage: %s serviceName num \\n\", argv[0]); return 1; } struct HdfIoService *srv = HdfIoServiceBind(argv[1]); if (srv == NULL) { printf(\"fail to get service\\n\"); return 1; } int ret = srv->dispatcher->Dispatch(&srv->object, atoi(argv[2]), NULL, NULL); printf(\"test end\\n\"); HdfIoServiceRecycle(srv); return 0;}

同目录下的BUILD.gn内容如下：

hdf_framework_path = \"../../../../../framework\"executable(\"mytest\") { sources = [ \"mytest.c\" ] include_dirs = [ \"$hdf_framework_path/ability/sbuf/include\", \"$hdf_framework_path/core/shared/include\", \"$hdf_framework_path/core/host/include\", \"$hdf_framework_path/core/master/include\", \"$hdf_framework_path/include/core\", \"$hdf_framework_path/include/utils\", \"$hdf_framework_path/utils/include\", \"$hdf_framework_path/include/osal\", \"//third_party/bounds_checking_function/include\", \"//base/hiviewdfx/hilog_lite/interfaces/native/innerkits\", ] deps = [ \"//drivers/hdf_core/adapter/uhdf/manager:hdf_core\", \"//drivers/hdf_core/adapter/uhdf/posix:hdf_posix_osal\", \"//base/hiviewdfx/hilog_lite/frameworks/featured:hilog_shared\", ] public_deps = [ \"//third_party/bounds_checking_function:libsec_shared\" ] defines = [ \"__USER__\" ]}

然后修改applications/sample/camera/bundle.json文件增加内容：

完成后编译系统，并重新烧录OHOS_Image.bin与rootfs_vfat.img

应用程序执行时通过指定不同的服务名与电平值控制LED，如：

 ./bin/mytest myTestService0 1 ./bin/mytest myTestService1 1