文章目录
- 一、效果展示
- 二、led控制程序
- 2.1、led驱动程序
- 2.1.1、驱动程序
- 2.1.2、驱动配置
- 2.2、C应用程序
- 2.3、JS应用
- 2.3.1、JS代码
- 2.3.2、C++接口
一、效果展示
小熊派micro OpenHarmony3.0 鸿蒙LED应用
二、led控制程序
本文按照小熊派官方的开发指南完成led应用程序开发,在开发指南的基础上添加一些自己的理解。
LED驱动虽然简单,但能帮助新手快速熟悉OpenHarmony HDF的开发框架,是非常适合新手学习实践的项目。
本文实现一个LED的开关控制的APP,所涉及的内容包括
- led驱动程序
- C应用程序
- JS应用程序
2.1、led驱动程序
使用HDF框架进行驱动开发,分两个部分:驱动程序,驱动配置。
2.1.1、驱动程序
驱动程序的代码在/device/st/driver/led/led.c
其主要是定义驱动程序入口函数,在HDF加载时读取配置信息并初始化GPIO,定义dispatch函数,用于处理与用户层的交互逻辑。
#include "hdf_device_desc.h"
#include "hdf_log.h"
#include "device_resource_if.h"
#include "osal_io.h"
#include "osal.h"
#include "osal_mem.h"
#include "gpio_if.h"
#define HDF_LOG_TAG led_driver
#define LED_WRITE_READ 1
enum LedOps {
LED_OFF,
LED_ON,
LED_TOGGLE,
};
struct Stm32Mp1ILed {
uint32_t gpioNum;
};
static struct Stm32Mp1ILed g_Stm32Mp1ILed;
uint8_t status = 0;
// 读取驱动私有配置(设备树)
static int32_t Stm32LedReadDrs(struct Stm32Mp1ILed *led, const struct DeviceResourceNode *node)
{
int32_t ret;
struct DeviceResourceIface *drsOps = NULL;
drsOps = DeviceResourceGetIfaceInstance(HDF_CONFIG_SOURCE);
if (drsOps == NULL || drsOps->GetUint32 == NULL) {
HDF_LOGE("%s: invalid drs ops!", __func__);
return HDF_FAILURE;
}
/* 读取led.hcs里面led_gpio_num的值 */
ret = drsOps->GetUint32(node, "led_gpio_num", &led->gpioNum, 0);
if (ret != HDF_SUCCESS) {
HDF_LOGE("%s: read led gpio num fail!", __func__);
return ret;
}
return HDF_SUCCESS;
}
// Dispatch是对外提供的服务,用来处理用户态发下来的消息,同时返回数据
int32_t LedDriverDispatch(struct HdfDeviceIoClient *client, int cmdCode, struct HdfSBuf *data, struct HdfSBuf *reply)
{
uint8_t contrl;
HDF_LOGE("Led driver dispatch");
if (client == NULL || client->device == NULL)
{
HDF_LOGE("Led driver device is NULL");
return HDF_ERR_INVALID_OBJECT;
}
switch (cmdCode)
{
/* 接收到用户态发来的LED_WRITE_READ命令 */
case LED_WRITE_READ:
/* 读取data里的数据,赋值给contrl */
HdfSbufReadUint8(data,&contrl);
switch (contrl)
{
/* 开灯 */
case LED_ON:
GpioWrite(g_Stm32Mp1ILed.gpioNum, GPIO_VAL_LOW);
status = 1;
break;
/* 关灯 */
case LED_OFF:
GpioWrite(g_Stm32Mp1ILed.gpioNum, GPIO_VAL_HIGH);
status = 0;
break;
/* 状态翻转 */
case LED_TOGGLE:
if(status == 0)
{
GpioWrite(g_Stm32Mp1ILed.gpioNum, GPIO_VAL_LOW);
status = 1;
}
else
{
GpioWrite(g_Stm32Mp1ILed.gpioNum, GPIO_VAL_HIGH);
status = 0;
}
break;
default:
break;
}
/* 把LED的状态值写入reply, 可被带至用户程序 */
if (!HdfSbufWriteInt32(reply, status))
{
HDF_LOGE("replay is fail");
return HDF_FAILURE;
}
break;
default:
break;
}
return HDF_SUCCESS;
}
//驱动对外提供的服务能力,将相关的服务接口绑定到HDF框架
int32_t HdfLedDriverBind(struct HdfDeviceObject *deviceObject)
{
if (deviceObject == NULL)
{
HDF_LOGE("Led driver bind failed!");
return HDF_ERR_INVALID_OBJECT;
}
//定义对外提供的服务函数
static struct IDeviceIoService ledDriver = {
.Dispatch = LedDriverDispatch,
};
//将服务绑定到驱动
deviceObject->service = (struct IDeviceIoService *)(&ledDriver);
HDF_LOGD("Led driver bind success");
return HDF_SUCCESS;
}
// 驱动自身业务初始的接口(设置IO口为输出) HDF框架在加载驱动的时候,会将私有配置信息保存在HdfDeviceObject 中的property里面
int32_t HdfLedDriverInit(struct HdfDeviceObject *device)
{
struct Stm32Mp1ILed *led = &g_Stm32Mp1ILed;
int32_t ret;
if (device == NULL || device->property == NULL) {
HDF_LOGE("%s: device or property NULL!", __func__);
return HDF_ERR_INVALID_OBJECT;
}
/* 读取hcs私有属性值,gpio引脚号 */
ret = Stm32LedReadDrs(led, device->property);
if (ret != HDF_SUCCESS) {
HDF_LOGE("%s: get led device resource fail:%d", __func__, ret);
return ret;
}
/* 将GPIO管脚配置为输出 */
ret = GpioSetDir(led->gpioNum, GPIO_DIR_OUT);
if (ret != 0)
{
HDF_LOGE("GpioSerDir: failed, ret %d\n", ret);
return ret;
}
HDF_LOGD("Led driver Init success");
return HDF_SUCCESS;
}
// 驱动资源释放的接口
void HdfLedDriverRelease(struct HdfDeviceObject *deviceObject)
{
if (deviceObject == NULL)
{
HDF_LOGE("Led driver release failed!");
return;
}
HDF_LOGD("Led driver release success");
return;
}
// 定义驱动入口的对象,必须为HdfDriverEntry(在hdf_device_desc.h中定义)类型的全局变量
struct HdfDriverEntry g_ledDriverEntry = {
.moduleVersion = 1,
.moduleName = "HDF_LED", //必须与device_info.hcs中的字段一样,用于与驱动设备资源匹配
.Bind = HdfLedDriverBind,
.Init = HdfLedDriverInit,
.Release = HdfLedDriverRelease,
};
// 调用HDF_INIT将驱动入口注册到HDF框架中
HDF_INIT(g_ledDriverEntry);
在创建完成led.c后,还要把它加入OpenHarmony的构建系统。
在led.c同目录下创建BUILD.gn,内容如下:
- 导入hdf.gni:
- 定义hdf驱动:驱动的源文件。
import("//drivers/adapter/khdf/liteos/hdf.gni")
hdf_driver("hdf_led") {
sources = [
"led.c",
]
}
在上层目录的BUILD.gn中的deps中添加"led"目录:
group("drivers") {
deps = [
"uart",
"iwdg",
"i2c",
"gpio",
"led",
"stm32mp1xx_hal",
"wifi/driver/hi3881",
"wifi/driver:hdf_vendor_wifi",
]
}
2.1.2、驱动配置
HDF使用HCS文件来描述设备配置信息。驱动配置包含两个部分:
- HDF框架规定的驱动设备描述:device/st/bearpi_hm_micro/liteos_a/hdf_config/device_info/device_info.hcs
- 驱动的私有配置信息:device/st/bearpi_hm_micro/liteos_a/hdf_config/led/led_config.hcs
HDF所需的驱动设备描述:
这些配置信息是HDF框架所需要的信息。
platform :: host {
hostName = "platform_host";
priority = 50;
device_led :: device { // led设备节点
device0 :: deviceNode { // led驱动的DeviceNode节点
policy = 2; // policy字段是驱动服务发布的策略,在驱动服务管理章节有详细介绍
priority = 10; // 驱动启动优先级(0-200),值越大优先级越低,建议默认配100,优先级相同则不保证device的加载顺序
preload = 1; // 驱动按需加载字段
permission = 0777; // 驱动创建设备节点权限
moduleName = "HDF_LED"; // 驱动名称,该字段的值必须和驱动入口结构的moduleName相等
serviceName = "hdf_led"; // 驱动对外发布服务的名称,必须唯一
deviceMatchAttr = "st_stm32mp157_led"; // 驱动私有数据匹配的关键字,必须和驱动私有数据配置表中的match_attr值相等
}
}
私有配置信息:
私有配置信息是可选的,在这里我们保存着led对应的gpio管脚号。
root {
LedDriverConfig {
led_gpio_num = 13; //gpio管脚号
match_attr = "st_stm32mp157_led"; //该字段的值必须和device_info.hcs中的deviceMatchAttr值一致
}
}
2.2、C应用程序
驱动程序已经完成了,现在来编写应用程序。
应用程序做的是:绑定hdf驱动提供的服务(通过"hdf_led",定义在device_info.hcs)并调用dispatch函数与驱动程序通信。通过0、1、2命令来使驱动程序输出高低电平。
需要注意的是应用程序不能直接读写驱动程序的变量、需要通过
HdfSBufObtainDefaultSize()
来申请内存,通过这个特殊的内存地址来跟驱动通信。
applications\BearPi\BearPi-HM_Micro\samples\my_led_app\my_led_app.c:
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <stdio.h>
#include "hdf_sbuf.h"
#include "hdf_io_service_if.h"
#define LED_WRITE_READ 1
#define LED_SERVICE "hdf_led" //这里和hdf.hcs里的节点属性一样
static int SendEvent(struct HdfIoService *service,uint8_t data)
{
//使用HdfSBufObtainDefaultSize申请内存,这种类型的内存才能用于和驱动程序交换数据
struct HdfSBuf *send_buf = HdfSBufObtainDefaultSize();
if(send_buf == NULL)
{
printf("send_buf fail\r\n");
return -1;
}
struct HdfSBuf *reply = HdfSBufObtainDefaultSize();
if(reply == NULL)
{
printf("reply fail\r\n");
goto out;
}
//将数据写入send_buf
if (!HdfSbufWriteUint8(send_buf, data))
{
printf("write send_buf fail\r\n");
goto out;
}
/* 通过Dispatch发送数据到驱动,同时驱动会将数据写入reply */
int ret = service->dispatcher->Dispatch(&service->object, LED_WRITE_READ, send_buf, reply);
if(ret != HDF_SUCCESS)
{
printf("Dispatch fail\r\n");
goto out;
}
int replyData = 0;
//读取reply的数据
if (!HdfSbufReadInt32(reply, &replyData))
{
printf("fail to get service call reply!\r\n");
goto out;
}
//回收内存
out:
HdfSBufRecycle(send_buf);
HdfSBufRecycle(reply);
return 0;
}
int main(int argc,char **argv)
{
int i;
if(argc < 2)
{
printf("error,argc < 1\r\n");
return -1;
}
//获取驱动提供的服务
struct HdfIoService *service = HdfIoServiceBind(LED_SERVICE);
if(service == NULL)
{
printf("fail get service %s \r\n",LED_SERVICE);
return -1;
}
//给驱动的服务发送数据
SendEvent(service,atoi(argv[1]));
//退订服务
HdfIoServiceRecycle(service);
printf("exit");
return 0;
}
要将my_led_app.c编译成可执行程序,并放在根文件系统。需要配置构建文件:
在my_led_app.c同目录下创建BUILD.gn:
import("//build/lite/config/component/lite_component.gni")
HDF_FRAMEWORKS = "//drivers/framework"
executable("led_lib"){
output_name = "my_led"
sources = [ "my_led_app.c" ]
include_dirs = [
"$HDF_FRAMEWORKS/ability/sbuf/include",
"$HDF_FRAMEWORKS/core/shared/include",
"$HDF_FRAMEWORKS/core/host/include",
"$HDF_FRAMEWORKS/core/master/include",
"$HDF_FRAMEWORKS/include/core",
"$HDF_FRAMEWORKS/include/utils",
"$HDF_FRAMEWORKS/utils/include",
"$HDF_FRAMEWORKS/include/osal",
"//drivers/adapter/uhdf/posix/include",
"//third_party/bounds_checking_function/include",
"//base/hiviewdfx/hilog_lite/interfaces/native/innerkits",
]
deps = [
"//base/hiviewdfx/hilog_lite/frameworks/featured:hilog_shared",
"//drivers/adapter/uhdf/manager:hdf_core",
"//drivers/adapter/uhdf/posix:hdf_posix_osal",
]
cflags_c = []
ldflags = []
}
lite_component("my_led_app")
{
features = [
":led_lib",
]
}
在build/lite/components/applications.json添加如下内容,将my_led_app编译成一个组件:
{
"component": "my_sample",
"description": "my samples",
"optional": "true",
"dirs": [
"applications/BearPi/BearPi-HM_Micro/samples/my_first_app",
"applications/BearPi/BearPi-HM_Micro/samples/my_led_app"
],
"targets": [
"//applications/BearPi/BearPi-HM_Micro/samples/my_first_app:my_app",
"//applications/BearPi/BearPi-HM_Micro/samples/my_led_app:my_led_app"
],
"rom": "",
"ram": "",
"output": [],
"adapted_kernel": [ "liteos_a" ],
"features": [],
"deps": {
"components": [],
"third_party": [ ]
}
},
2.3、JS应用
2.3.1、JS代码
JS程序本质上也是调用了驱动程序所提供的服务来控制Led,与上一节的区别是使用的编程语言不同。JS代码通过
app.ledcontrol
来调用C++提供的接口,实际的控制逻辑由C++提供的
ledcontrol
实现。
首先看应用程序的JS代码:其本质就是调用ledcontrol函数,通过传递不同的参数来实现led的控制。
//灯状态 0是关闭 1是开启 2是切换
var led = {open:1,close:0,change:2}
import app from '@system.app';
export default {
data: {
title: 'BearPi-HM Micro',
statu:'0'
},
exit(e){
app.terminate()
},
open(e){
let that = this
//调用ledcontrol函数、传递参数code、success、fail、complete
app.ledcontrol({
code:led.open,
success(res){
that.statu = res.led_status
},
fail(res,code){
},
complete(){
}
})
},
close(e){
let that = this
app.ledcontrol({
code:led.close,
success(res){
that.statu = res.led_status
},
fail(res,code){
},
complete(){
}
})
},
change(e){
let that = this
app.ledcontrol({
code:led.change,
success(res){
that.statu = res.led_status
},
fail(res,code){
},
complete(){
}
})
}
}
2.3.2、C++接口
JS代码中的app.ledcontrol要能运行起来,需要C++提供对应的函数。
步骤如下:
1、在foundation\ace\ace_engine_lite\frameworks\src\core\modules\app_module.h中public声明ToggleLed函数。
public:
ACE_DISALLOW_COPY_AND_MOVE(AppModule);
AppModule() = default;
~AppModule() = default;
static JSIValue GetInfo(const JSIValue thisVal, const JSIValue *args, uint8_t argsNum);
static JSIValue Terminate(const JSIValue thisVal, const JSIValue *args, uint8_t argsNum);
static JSIValue ToggleLed(const JSIValue thisVal, const JSIValue* args, uint8_t argsNum);
接着在InitAppModule()中将ToggleLed注册到JS API中,这样JS代码就能通过ledcontrol接口调用ToggleLed函数。
void InitAppModule(JSIValue exports)
{
JSI::SetModuleAPI(exports, "getInfo", AppModule::GetInfo);
JSI::SetModuleAPI(exports, "terminate", AppModule::Terminate);
JSI::SetModuleAPI(exports, "ledcontrol", AppModule::ToggleLed);
2、在foundation\ace\ace_engine_lite\frameworks\src\core\modules\app_module.cpp中实现ToggleLed()
首先添加头文件和宏定义:
#include "hdf_sbuf.h"
#include "hdf_io_service_if.h"
#define LED_WRITE_READ 1
#define LED_SERVICE "hdf_led"
添加ToggleLed()的定义:将以下代码与2.2 LED应用程序比较、不难看出两者逻辑是相同的,差别在于C++这里需要处理success、fail、complete的回调。
static int OnDevEventReceived(void *priv, uint32_t id, struct HdfSBuf *data)
{
uint32_t value;
HdfSbufReadUint32(data, &value);
HILOG_ERROR(HILOG_MODULE_ACE,"%s: dev event received: %u %u\n", (char *)priv, id, value);
return HDF_SUCCESS;
}
//向led驱动发送数据并返回结果
static int GpioWriteRead(struct HdfIoService *serv, int32_t eventData, int32_t *val)
{
int ret = HDF_FAILURE;
//申请内存用于和HDF驱动通信
struct HdfSBuf *data = HdfSBufObtainDefaultSize();
struct HdfSBuf *reply = HdfSBufObtainDefaultSize();
if (data == NULL || reply == NULL) {
HILOG_ERROR(HILOG_MODULE_ACE,"fail to obtain sbuf data\n");
return ret;
}
//将eventData的数据复制到data
if (!HdfSbufWriteUint8(data, (uint8_t)eventData))
{
HILOG_ERROR(HILOG_MODULE_ACE,"fail to write sbuf\n");
HdfSBufRecycle(data);
HdfSBufRecycle(reply);
return ret;
}
//调用驱动的dispatch函数,向led驱动发送数据并接收返回结果。
ret = serv->dispatcher->Dispatch(&serv->object, LED_WRITE_READ, data, reply);
if (ret != HDF_SUCCESS)
{
HILOG_ERROR(HILOG_MODULE_ACE,"fail to send service call\n");
HdfSBufRecycle(data);
HdfSBufRecycle(reply);
return ret;
}
//读取返回结果到reply
if (!HdfSbufReadInt32(reply, val))
{
HILOG_ERROR(HILOG_MODULE_ACE,"fail to get service call reply\n");
ret = HDF_ERR_INVALID_OBJECT;
HdfSBufRecycle(data);
HdfSBufRecycle(reply);
return ret;
}
HILOG_ERROR(HILOG_MODULE_ACE,"Get reply is: %d\n", val);
//释放内存
HdfSBufRecycle(data);
HdfSBufRecycle(reply);
return ret;
}
//led控制
JSIValue AppModule::ToggleLed(const JSIValue thisVal, const JSIValue *args, uint8_t argsNum)
{
HILOG_ERROR(HILOG_MODULE_ACE, "led button pressed.");
//获取led驱动提供的服务
struct HdfIoService *serv = HdfIoServiceBind(LED_SERVICE);
if (serv == NULL)
{
HILOG_ERROR(HILOG_MODULE_ACE,"fail to get service2 %s\n", LED_SERVICE);
return JSI::CreateUndefined();
}
if ((args == nullptr) || (argsNum == 0) || (JSI::ValueIsUndefined(args[0]))) {
return JSI::CreateUndefined();
}
//获取JS代码中的success、fail、complete的?
JSIValue success = JSI::GetNamedProperty(args[0], CB_SUCCESS);
JSIValue fail = JSI::GetNamedProperty(args[0], CB_FAIL);
JSIValue complete = JSI::GetNamedProperty(args[0], CB_COMPLETE);
//获取code的值,即JS代码中的 code:led.open,也就是 0、1、2控制码
int32_t num = (int32_t)JSI::GetNumberProperty(args[0], "code");
int32_t replyData = 0;
//将命令发送到led驱动
if (GpioWriteRead(serv, num, &replyData))
{
//驱动led失败、调用fail、complete函数
HILOG_ERROR(HILOG_MODULE_ACE,"fail to send event\n");
JSI::CallFunction(fail, thisVal, nullptr, 0);
JSI::CallFunction(complete, thisVal, nullptr, 0);
JSI::ReleaseValueList(success, fail, complete);
return JSI::CreateUndefined();
}
//驱动led成功,返回结果对象
JSIValue result = JSI::CreateObject();
//设置结果对象中的led_status属性值。对应js代码中的"that.statu = res.led_status"
JSI::SetNumberProperty(result, "led_status", replyData);
//调用success、complete函数
JSIValue argv[ARGC_ONE] = {result};
JSI::CallFunction(success, thisVal, argv, ARGC_ONE);
JSI::CallFunction(complete, thisVal, nullptr, 0);
JSI::ReleaseValueList(success, fail, complete, result);
HdfIoServiceRecycle(serv);
return JSI::CreateUndefined();
}
3、将编写的源文件添加到编译系统。
首先配置HDF头文件路径:
在foundation\ace\ace_engine_lite\ace_lite.gni中添加HDF头文件路径
ace_lite_include_dirs += [
"//drivers/framework/ability/sbuf/include",
"//drivers/framework/include/core",
"//drivers/framework/include/utils",
"//drivers/adapter/uhdf/posix/include",
]
添加编译依赖:
修改foundation\ace\ace_engine_lite\frameworks\BUILD.gn,在public_deps中添加以下代码
"//drivers/adapter/uhdf/manager:hdf_core",
"//drivers/adapter/uhdf/manager:hdf_core",