HDF开发实例

下面基于HDF框架，提供一个完整的样例，包含配置文件的添加，驱动代码的实现以及用户态程序和驱动交互的流程。

添加配置

在HDF框架的配置文件（例如vendor/hisi/hi35xx/hi3516dv300/config/device_info/device_info.hcs）中添加该驱动的配置信息，如下所示：

  1. root {
  2.     device_info {
  3.         match_attr = "hdf_manager";
  4.         template host {
  5.             hostName = "";
  6.             priority = 100;
  7.             template device {
  8.                 template deviceNode {
  9.                     policy = 0;
  10.                     priority = 100;
  11.                     preload = 0;
  12.                     permission = 0664;
  13.                     moduleName = "";
  14.                     serviceName = "";
  15.                     deviceMatchAttr = "";
  16.                 }
  17.             }
  18.         }
  19.         sample_host :: host {
  20.             hostName = "sample_host";
  21.             sample_device :: device {
  22.                 device0 :: deviceNode {
  23.                     policy = 2;
  24.                     priority = 100;
  25.                     preload = 1;
  26.                     permission = 0664;
  27.                     moduleName = "sample_driver";
  28.                     serviceName = "sample_service";
  29.                 }
  30.             }
  31.         }
  32.     }
  33. }

编写驱动代码

基于HDF框架编写的sample驱动代码如下：

  1. #include <fcntl.h>
  2. #include <sys/stat.h>
  3. #include <sys/ioctl.h>
  4. #include "hdf_log.h"
  5. #include "hdf_base.h"
  6. #include "hdf_device_desc.h"
  8. #define HDF_LOG_TAG sample_driver
  10. #define SAMPLE_WRITE_READ 123
  12. int32_t HdfSampleDriverDispatch(
  13.     struct HdfDeviceObject *deviceObject, int id, struct HdfSBuf *data, struct HdfSBuf *reply)
  14. {
  15.     HDF_LOGE("%s: received cmd %d", __func__, id);
  16.     if (id == SAMPLE_WRITE_READ) {
  17.         const char *readData = HdfSbufReadString(data);
  18.         if (readData != NULL) {
  19.             HDF_LOGE("%s: read data is: %s", __func__, readData);
  20.         }
  21.         if (!HdfSbufWriteInt32(reply, INT32_MAX)) {
  22.             HDF_LOGE("%s: reply int32 fail", __func__);
  23.         }
  24.         return HdfDeviceSendEvent(deviceObject, id, data);
  25.     }
  26.     return HDF_FAILURE;
  27. }
  29. void HdfSampleDriverRelease(struct HdfDeviceObject *deviceObject)
  30. {
  31.     // release resources here
  32.     return;
  33. }
  35. int HdfSampleDriverBind(struct HdfDeviceObject *deviceObject)
  36. {
  37.     if (deviceObject == NULL) {
  38.         return HDF_FAILURE;
  39.     }
  40.     static struct IDeviceIoService testService = {
  41.         .Dispatch = HdfSampleDriverDispatch,
  42.     };
  43.     deviceObject->service = &testService;
  44.     return HDF_SUCCESS;
  45. }
  47. int HdfSampleDriverInit(struct HdfDeviceObject *deviceObject)
  48. {
  49.     if (deviceObject == NULL) {
  50.         HDF_LOGE("%s::ptr is null!", __func__);
  51.         return HDF_FAILURE;
  52.     }
  53.     HDF_LOGE("Sample driver Init success");
  54.     return HDF_SUCCESS;
  55. }
  57. struct HdfDriverEntry g_sampleDriverEntry = {
  58.     .moduleVersion = 1,
  59.     .moduleName = "sample_driver",
  60.     .Bind = HdfSampleDriverBind,
  61.     .Init = HdfSampleDriverInit,
  62.     .Release = HdfSampleDriverRelease,
  63. };
  65. HDF_INIT(g_sampleDriverEntry);

编写用户程序和驱动交互代码

基于HDF框架编写的用户态程序和驱动交互的代码如下：

  1. #include <fcntl.h>
  2. #include <sys/stat.h>
  3. #include <sys/ioctl.h>
  4. #include <unistd.h>
  5. #include "hdf_log.h"
  6. #include "hdf_sbuf.h"
  7. #include "hdf_io_service_if.h"
  9. #define HDF_LOG_TAG "sample_test"
  10. #define SAMPLE_SERVICE_NAME "sample_service"
  12. #define SAMPLE_WRITE_READ 123
  14. int g_replyFlag = 0;
  16. static int OnDevEventReceived(void *priv,  uint32_t id, struct HdfSBuf *data)
  17. {
  18.     const char *string = HdfSbufReadString(data);
  19.     if (string == NULL) {
  20.         HDF_LOGE("fail to read string in event data");
  21.         g_replyFlag = 1;
  22.         return HDF_FAILURE;
  23.     }
  24.     HDF_LOGE("%s: dev event received: %u %s",  (char *)priv, id, string);
  25.     g_replyFlag = 1;
  26.     return HDF_SUCCESS;
  27. }
  29. static int SendEvent(struct HdfIoService *serv, char *eventData)
  30. {
  31.     int ret = 0;
  32.     struct HdfSBuf *data = HdfSBufObtainDefaultSize();
  33.     if (data == NULL) {
  34.         HDF_LOGE("fail to obtain sbuf data");
  35.         return 1;
  36.     }
  38.     struct HdfSBuf *reply = HdfSBufObtainDefaultSize();
  39.     if (reply == NULL) {
  40.         HDF_LOGE("fail to obtain sbuf reply");
  41.         ret = HDF_DEV_ERR_NO_MEMORY;
  42.         goto out;
  43.     }
  45.     if (!HdfSbufWriteString(data, eventData)) {
  46.         HDF_LOGE("fail to write sbuf");
  47.         ret = HDF_FAILURE;
  48.         goto out;
  49.     }
  51.     ret = serv->dispatcher->Dispatch(&serv->object, SAMPLE_WRITE_READ, data, reply);
  52.     if (ret != HDF_SUCCESS) {
  53.         HDF_LOGE("fail to send service call");
  54.         goto out;
  55.     }
  57.     int replyData = 0;
  58.     if (!HdfSbufReadInt32(reply, &replyData)) {
  59.         HDF_LOGE("fail to get service call reply");
  60.         ret = HDF_ERR_INVALID_OBJECT;
  61.         goto out;
  62.     }
  63.     HDF_LOGE("Get reply is: %d", replyData);
  64. out:
  65.     HdfSBufRecycle(data);
  66.     HdfSBufRecycle(reply);
  67.     return ret;
  68. }
  70. int main()
  71. {
  72.     char *sendData = "default event info";
  73.     struct HdfIoService *serv = HdfIoServiceBind(SAMPLE_SERVICE_NAME, 0);
  74.     if (serv == NULL) {
  75.         HDF_LOGE("fail to get service %s", SAMPLE_SERVICE_NAME);
  76.         return HDF_FAILURE;
  77.     }
  79.     static struct HdfDevEventlistener listener = {
  80.         .callBack = OnDevEventReceived,
  81.         .priv ="Service0"
  82.     };
  84.     if (HdfDeviceRegisterEventListener(serv, &listener) != HDF_SUCCESS) {
  85.         HDF_LOGE("fail to register event listener");
  86.         return HDF_FAILURE;
  87.     }
  88.     if (SendEvent(serv, sendData)) {
  89.         HDF_LOGE("fail to send event");
  90.         return HDF_FAILURE;
  91.     }
  93.     /* wait for event receive event finishing */
  94.     while (g_replyFlag == 0) {
  95.         sleep(1);
  96.     }
  98.     if (HdfDeviceUnregisterEventListener(serv, &listener)) {
  99.         HDF_LOGE("fail to  unregister listener");
  100.         return HDF_FAILURE;
  101.     }
  103.     HdfIoServiceRecycle(serv);
  104.     return HDF_SUCCESS;
  105. }

HDF开发实例 - 图1 说明： 用户态应用程序使用了HDF框架中的消息发送接口，因此在编译用户态程序的过程中需要依赖HDF框架对外提供的hdf_core和osal的动态库，在gn编译文件中添加如下依赖项： deps = [ “//drivers/hdf/lite/manager:hdf_core”, “//drivers/hdf/lite/adapter/osal/posix:hdf_posix_osal”, ]