小熊派:用OpenHarmory3.0點亮LED

語言: CN / TW / HK
摘要:作為一個代表性的完整的開發,本案例可以分成3大部分:程式碼檔案的規劃,LED燈的驅動開發,點亮LED的業務開發。

本文分享自華為雲社群《在小熊派Micro上用OpenHarmory3.0點亮LED(1)LED驅動開發》,作者:神龍居市。

專案總覽

作為一個代表性的完整的開發,本案例可以分成3大部分:程式碼檔案的規劃,LED燈的驅動開發,點亮LED的業務開發。

一、LED驅動開發

1.1.確定目錄結構

1.1.1.根據HDF框架以元件化的驅動模型作為核心設計思路,HDF框架將一類裝置驅動放在同一個host裡面,開發者也可以將驅動功能分層獨立開發和部署,支援一個驅動多個node,HDF驅動模型如下圖

1.1.2.本案例目錄

在./device/st/drivers路徑下新建一個led的目錄,用來存放驅動原始碼檔案。

在./device/st/bearpi_hm_micro/liteos_a/hdf_config路徑下新建led資料夾,並建立驅動配置檔案led_config.hcs

1.2.LED驅動實現

1.2.1.驅動實現包含驅動業務程式碼和驅動入口註冊,在led.c檔案中新增以下程式碼

#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 // 列印日誌所包含的標籤,如果不定義則用預設定義的HDF_TAG標籤
#define LED_WRITE_READ 1       // 讀寫操作碼1

enum LedOps {
    LED_OFF,
    LED_ON,  
    LED_TOGGLE,
};

struct Stm32Mp1ILed {
    uint32_t gpioNum;
};
static struct Stm32Mp1ILed g_Stm32Mp1ILed;
uint8_t status = 0;
// Dispatch是用來處理使用者態發下來的訊息
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)
    {
    /* 接收到使用者態發來的LED_WRITE_READ命令 */
    case LED_WRITE_READ:
        /* 讀取data裡的資料,賦值給contrl */
        HdfSbufReadUint8(data,&contrl);                  
        switch (contrl)
        {
        /* 開燈 */
        case LED_ON:                                            
            GpioWrite(g_Stm32Mp1ILed.gpioNum, GPIO_VAL_LOW);
            status = 1;
            break;
        /* 關燈 */
        case LED_OFF:                                           
            GpioWrite(g_Stm32Mp1ILed.gpioNum, GPIO_VAL_HIGH);
            status = 0;
            break;
        /* 狀態翻轉 */
        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的狀態值寫入reply, 可被帶至使用者程式 */
        if (!HdfSbufWriteInt32(reply, status))                
        {
            HDF_LOGE("replay is fail");
            return HDF_FAILURE;
        }
        break;
    default:
        break;
    }
    return HDF_SUCCESS;
}

// 讀取驅動私有配置
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;
    }
    /* 讀取led.hcs裡面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;
}

//驅動對外提供的服務能力,將相關的服務介面繫結到HDF框架
int32_t HdfLedDriverBind(struct HdfDeviceObject *deviceObject)
{
    if (deviceObject == NULL)
    {
        HDF_LOGE("Led driver bind failed!");
        return HDF_ERR_INVALID_OBJECT;
    }
    static struct IDeviceIoService ledDriver = {
        .Dispatch = LedDriverDispatch,
    };
    deviceObject->service = (struct IDeviceIoService *)(&ledDriver);
    HDF_LOGD("Led driver bind success");
    return HDF_SUCCESS;
}

// 驅動自身業務初始的介面
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;
    }
    /* 讀取hcs私有屬性值 */
    ret = Stm32LedReadDrs(led, device->property);
    if (ret != HDF_SUCCESS) {
        HDF_LOGE("%s: get led device resource fail:%d", __func__, ret);
        return ret;
    }
    /* 將GPIO管腳配置為輸出 */
    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;
}

// 驅動資源釋放的介面
void HdfLedDriverRelease(struct HdfDeviceObject *deviceObject)
{
    if (deviceObject == NULL)
    {
        HDF_LOGE("Led driver release failed!");
        return;
    }
    HDF_LOGD("Led driver release success");
    return;
}

// 定義驅動入口的物件,必須為HdfDriverEntry(在hdf_device_desc.h中定義)型別的全域性變數
struct HdfDriverEntry g_ledDriverEntry = {
    .moduleVersion = 1,
    .moduleName = "HDF_LED",
    .Bind = HdfLedDriverBind,
    .Init = HdfLedDriverInit,
    .Release = HdfLedDriverRelease,
};

// 呼叫HDF_INIT將驅動入口註冊到HDF框架中
HDF_INIT(g_ledDriverEntry);

1.2.2.編譯指令碼檔案

在led/BUILD.gn檔案中新增以下程式碼,將led.c編譯成hdf_led

import("//drivers/adapter/khdf/liteos/hdf.gni")
hdf_driver("hdf_led") {
    sources = [
    "led.c",
    ]
}

在/device/st/drivers/BUILD.gn檔案中新增以下程式碼,將hdf_led編譯進核心,"led"是新增內容

1.3.驅動配置

HDF使用HCS作為配置描述原始碼,驅動配置包含兩部分,HDF框架定義的驅動裝置描述和驅動的私有配置資訊。

HDF框架載入驅動所需要的資訊來源於HDF框架定義的驅動裝置描述,因此基於HDF框架開發的驅動必須要在HDF框架定義的device_info.hcs配置檔案中新增對應的裝置描述,所以我們需要在device\st\bearpi_hm_micro\liteos_a\hdf_config\device_info\device_info.hcs中新增LED裝置描述

device_led :: device {             // led裝置節點
    device0 :: deviceNode {        // led驅動的DeviceNode節點
        policy = 2;                // policy欄位是驅動服務釋出的策略,在驅動服務管理章節有詳細介紹
        priority = 10;             // 驅動啟動優先順序(0-200),值越大優先順序越低,建議預設配100,優先順序相同則不保證device的載入順序
        preload = 1;               // 驅動按需載入欄位
        permission = 0777;         // 驅動建立裝置節點許可權
        moduleName = "HDF_LED";    // 驅動名稱,該欄位的值必須和驅動入口結構的moduleName值一致
        serviceName = "hdf_led";   // 驅動對外發布服務的名稱,必須唯一
        deviceMatchAttr = "st_stm32mp157_led"; // 驅動私有資料匹配的關鍵字,必須和驅動私有資料配置表中的match_attr值相等
    }
}  

1.4.私有驅動資訊配置

如果驅動有私有配置,則可以新增一個驅動的配置檔案,用來填寫一些驅動的預設配置資訊,HDF框架在載入驅動的時候,會將對應的配置資訊獲取並儲存在HdfDeviceObject 中的property裡面,通過Bind和Init傳遞給驅動,所以我們需要在device\st\bearpi_hm_micro\liteos_a\hdf_config\led\led_config.hcs中新增LED私有配置描述。

root {
    LedDriverConfig {
        led_gpio_num = 13;
        match_attr = "st_stm32mp157_led";   //該欄位的值必須和device_info.hcs中的deviceMatchAttr值一致
    }
}

1.5.板級配置入口檔案

配置資訊定義之後,需要將該配置檔案新增到板級配置入口檔案device\st\bearpi_hm_micro\liteos_a\hdf_config\hdf.hcs

#include "device_info/device_info.hcs"
#include "led/led_config.hcs"

二、點亮LED業務程式碼

2.1.建立目錄

編寫業務時,務必先在./applications/BearPi/BearPi-HM_Micro/samples路徑下新建一個目錄(或一套目錄結構),用於存放業務原始碼檔案.

在samples資料夾下增加my_led_app資料夾,並新建BUILD.gn和my_led_app.c兩個檔案

2.2.編寫業務程式碼

在my_led_app.c中新增以下業務程式碼

#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"

static int SendEvent(struct HdfIoService *serv, uint8_t eventData)
{
    int ret = 0;
    struct HdfSBuf *data = HdfSBufObtainDefaultSize();
    if (data == NULL)
    {
        printf("fail to obtain sbuf data!\r\n");
        return 1;
    }

    struct HdfSBuf *reply = HdfSBufObtainDefaultSize();
    if (reply == NULL)
    {
        printf("fail to obtain sbuf reply!\r\n");
        ret = HDF_DEV_ERR_NO_MEMORY;
        goto out;
    }
    /* 寫入資料 */
    if (!HdfSbufWriteUint8(data, eventData))
    {
        printf("fail to write sbuf!\r\n");
        ret = HDF_FAILURE;
        goto out;
    }
    /* 通過Dispatch傳送到驅動 */
    ret = serv->dispatcher->Dispatch(&serv->object, LED_WRITE_READ, data, reply);
    if (ret != HDF_SUCCESS)
    {
        printf("fail to send service call!\r\n");
        goto out;
    }

    int replyData = 0;
    /* 讀取驅動的回覆資料 */
    if (!HdfSbufReadInt32(reply, &replyData))
    {
        printf("fail to get service call reply!\r\n");
        ret = HDF_ERR_INVALID_OBJECT;
        goto out;
    }
    printf("\r\nGet reply is: %d\r\n", replyData);
out:
    HdfSBufRecycle(data);
    HdfSBufRecycle(reply);
    return ret;
}

int main(int argc, char **argv)
{
    int i;
 
    /* 獲取服務 */
    struct HdfIoService *serv = HdfIoServiceBind(LED_SERVICE);
    if (serv == NULL)
    {
        printf("fail to get service %s!\r\n", LED_SERVICE);
        return HDF_FAILURE;
    }

    for (i=0; i < argc; i++)
    {
        printf("\r\nArgument %d is %s.\r\n", i, argv[i]);
    }

    SendEvent(serv, atoi(argv[1]));

    HdfIoServiceRecycle(serv);
    printf("exit");

    return HDF_SUCCESS;
}

2.3.編寫將構建業務程式碼的BUILD.gn檔案

BUILD.gn檔案由三部分內容(目標、原始檔、標頭檔案路徑)構成,需由開發者完成填寫。以my_led_app為例,需要建立./applications/BearPi/BearPi-HM_Micro/samples/my_led_app/BUILD.gn,並完如下配置

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",
    ]
}

lite_component("my_led_app") {
    features = [
        ":led_lib",
    ]
}
  1. 首先匯入 gni 元件,將原始碼my_led_app.c編譯成led_lib庫檔案
  2. 輸出的可執行檔名稱由 output_name 定義為my_led
  3. include_dirs 裡面加入my_led_app.c裡面需要用到的.h的標頭檔案路徑
  4. deps 裡面加入所依賴的庫。
  5. 然後將led_lib打包成 lite_component,命名為my_led_app元件。

2.4.新增新元件

修改檔案build/lite/components/applications.json,新增元件my_sample的配置

{
        "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": [ ]
        }
    },

2.5.修改單板配置檔案

修改檔案vendor/bearpi/bearpi_hm_micro/config.json,新增my_sample元件的條目

{
      "subsystem": "applications",
      "components": [
         { "component": "my_sample", "features":[] },
         { "component": "bearpi_sample_app", "features":[] },
         { "component": "bearpi_screensaver_app", "features":[] }
      ]
},

三、編譯

在專案根目錄下執行hb set 設定開發板,只有一個,回車即可

執行編譯命令

hb build -t notest --tee -f

等待編譯完成後,螢幕出現:build success字樣,說明編譯成功。

當編譯完後,可以直接檢視到最終編譯的韌體,具體路徑在: \project\bearpi-hm_micro_small\out\bearpi-hm_micro\bearpi-hm_micro

資料夾結構說明

  • OHOS_Image.stm32:系統映象檔案
  • rootfs_vfat.img:根檔案系統
  • userfs_vfat.img:使用者檔案系統

執行以下三條指令將以上三個檔案複製到applications/BearPi/BearPi-HM_Micro/tools/download_img/kernel/下,以便後續燒錄系統使用

cp out/bearpi_hm_micro/bearpi_hm_micro/OHOS_Image.stm32 applications/BearPi/BearPi-HM_Micro/tools/download_img/kernel/
cp out/bearpi_hm_micro/bearpi_hm_micro/rootfs_vfat.img applications/BearPi/BearPi-HM_Micro/tools/download_img/kernel/
cp out/bearpi_hm_micro/bearpi_hm_micro/userfs_vfat.img applications/BearPi/BearPi-HM_Micro/tools/download_img/kernel/

四、總結

至此,完整的專案工程就開發好了,下一步就是燒錄和運行了。

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