IOKIT 使用 PID 和 VID 检测 USB 串行设备的 BSD(unix) 名称

Question

我正在 macOS 上使用 USB 串行设备。

如何使用 IOKit 在 macOS 上检测我的 USB 串行设备的 BSD(unix) 名称？我想获得如下设备名称："IODialinDevice" = "/dev/tty.usbmodemMyDeviceName"

我的USB设备是USB串口。我还想检测设备何时连接到机器。

我可以检测到何时连接了带有我的 VID 和 PID 的新 USB 设备。此代码允许我这样做

CFMutableDictionaryRef keywordDict = IOServiceMatching(kIOSerialBSDServiceValue);

kern_return_t result = IOServiceGetMatchingServices(kIOMasterPortDefault, keywordDict, &iterator);

while ((port = IOIteratorNext(iterator)))
{
        io_object_t parent = 0;                     
        io_object_t current_device = port;
        while (KERN_SUCCESS == IORegistryEntryGetParentEntry(current_device, kIOServicePlane, &parent))
        {
            CFTypeRef vendor_Id = IORegistryEntryCreateCFProperty(parent, CFSTR(kUSBVendorID), kCFAllocatorDefault, 0);
            CFTypeRef pr_Id = IORegistryEntryCreateCFProperty(parent, CFSTR(kUSBProductID), kCFAllocatorDefault, 0);

            if((vendor_id==MY_VENDOR_ID) && (pr_ID==MY_PRODUCT_ID))
            {
                // MY SERIAL DEVICE DETECTED !! 
                CFTypeRef deviceName = IORegistryEntryCreateCFProperty(device, key, CFSTR(kIOTTYDeviceKey), 0);
                CFTypeRef callOutDevice = IORegistryEntryCreateCFProperty(device, key, CFSTR(kIOCalloutDeviceKey), 0);
                CFTypeRef dialInDevice = IORegistryEntryCreateCFProperty(device, key, CFSTR(kIODialinDeviceKey), 0);

            }
        }
}

但是这个代码不允许我检测到新设备的问题。我只是在这里枚举现有的 kIOSerialBSDServiceValue 设备，然后我检查 parents VID 和 PID 如果 parent 有 MY_VID 和 MY_PID 我假设我找到了正确的串行设备。

另一个代码允许我检测新的 USB 设备

这是 Apple 示例 LUSBPrivateDataSample.c 我可以使用以下代码使用 VID 和 PID 检测我的设备

   int main()
   {
    ...
    ...
    ...

    // Create a CFNumber for the idVendor and set the value in the dictionary
    numberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &usbVendor);
    CFDictionarySetValue(matchingDict, 
                         CFSTR(kUSBVendorID), 
                         numberRef);
    CFRelease(numberRef);

    // Create a CFNumber for the idProduct and set the value in the dictionary
    numberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &usbProduct);
    CFDictionarySetValue(matchingDict, 
                         CFSTR(kUSBProductID), 
                         numberRef);
    CFRelease(numberRef);

    ...
    ...
    ...

        // Now set up a notification to be called when a device is first matched by I/O Kit.
    kr = IOServiceAddMatchingNotification(gNotifyPort,                  // notifyPort
                                          kIOFirstMatchNotification,    // notificationType
                                          matchingDict,                 // matching
                                          DeviceAdded,                  // callback
                                          NULL,                         // refCon
                                          &gAddedIter                   // notification
                                          );    

    }

    void DeviceAdded(void *refCon, io_iterator_t iterator)
    {
        io_service_t        usbDevice;
        while ((usbDevice = IOIteratorNext(iterator)))
        {
                // I have device here but I can't get IODialinDevice device name 
        }
    }

此代码的问题是我无法获取 IODialinDevice 设备名称我还检查了这个 usbDevice 的所有 child 个节点。 None 其中包含 IODialinDevice 属性或 none 其中是 kIOSerialBSDServiceValue 设备。

看来我做错了。看起来串行设备和 USB 位于不同的 IOKit 注册表分支中。问题是如何使用 IODialinDevice ("/dev/tty.usbmodemMyDeviceName") 属性从 VID 和 PID 识别的 USB 设备到串行设备 (kIOSerialBSDServiceValue)。

感谢任何帮助！

更新： 这是 ioreg 树：
我可以在我的应用程序中检测到 CDC ACM 数据设备。（这棵树中的顶级设备）在 ioreg 中，我看到了这张图片。所以有 children、AppleUSBACMData 和 IOSerialBSDClient 拥有 IODialinDevice 属性。但是我无法在我的应用程序中检测到 AppleUSBACMData 和 IOSerialBSDClient。可能是因为 AppleUSBACMData 和 IOSerialBSDClient 不是设备，而是 USB 接口或 USB 端点。所以这是我的问题。

+-o CDC ACM Data@3  <class IOUSBHostInterface, id 0x100090fff, registered, matched, active, busy 0 (514 ms), retain 7>
  | {
  |   "USBPortType" = 0
  |   "IOCFPlugInTypes" = {"2d9786c6-9ef3-11d4-ad51-000a27052861"="IOUSBFamily.kext/Contents/PlugIns/IOUSBLib.bundle"}
  |   "Product Name" = "DevName"
  |   "bcdDevice" = 1044
  |   "USBSpeed" = 3
  |   "idProduct" = 260
  |   "bConfigurationValue" = 1
  |   "bInterfaceSubClass" = 0
  |   "locationID" = 338886656
  |   "IOGeneralInterest" = "IOCommand is not serializable"
  |   "IOServiceLegacyMatchingRegistryID" = 4295561221
  |   "IOClassNameOverride" = "IOUSBInterface"
  |   "AppleUSBAlternateServiceRegistryID" = 4295561221
  |   "idVendor" = 7777
  |   "bInterfaceProtocol" = 0
  |   "bAlternateSetting" = 0
  |   "bInterfaceNumber" = 3
  |   "bInterfaceClass" = 10
  | }
  | 
  +-o AppleUSBACMData  <class AppleUSBACMData, id 0x100091018, registered, matched, active, busy 0 (0 ms), retain 6>
    | {
    |   "IOClass" = "AppleUSBACMData"
    |   "CFBundleIdentifier" = "com.apple.driver.usb.cdc.acm"
    |   "IOProviderClass" = "IOUSBHostInterface"
    |   "IOTTYBaseName" = "usbmodem"
    |   "idProduct" = 260
    |   "IOProbeScore" = 49999
    |   "bInterfaceSubClass" = 0
    |   "HiddenPort" = Yes
    |   "IOMatchCategory" = "IODefaultMatchCategory"
    |   "idVendor" = 7777
    |   "IOTTYSuffix" = "DevName_B3"
    |   "bInterfaceClass" = 10
    | }
    | 
    +-o IOSerialBSDClient  <class IOSerialBSDClient, id 0x100091020, registered, matched, active, busy 0 (0 ms), retain 5>
    {
       "IOClass" = "IOSerialBSDClient" 
        "CFBundleIdentifier" = "com.apple.iokit.IOSerialFamily"
        "IOProviderClass" = "IOSerialStreamSync"
        "IOTTYBaseName" = "usbmodem"
        "IOSerialBSDClientType" = "IORS232SerialStream"
        "IOProbeScore" = 1000
        "IOCalloutDevice" = "/dev/cu.usbmodemDevName_B3"
        "IODialinDevice" = "/dev/tty.usbmodemDevName_B3"
        "IOMatchCategory" = "IODefaultMatchCategory"
        "IOTTYDevice" = "usbmodemDevName_B3"
        "IOResourceMatch" = "IOBSD"
        "IOTTYSuffix" = "DevName_B3"
    }

Answer 1

解决方法很简单。它一直在我的办公桌上。您应该订阅接收有关新 kIOSerialBSDServiceValue 设备出现在系统中的通知像这样。此代码也基于 Apple USBPrivateDataSample.c

https://developer.apple.com/library/archive/samplecode/USBPrivateDataSample/Introduction/Intro.html#//apple_ref/doc/uid/DTS10000456

CFMutableDictionaryRef matchingDict = IOServiceMatching(kIOSerialBSDServiceValue);
....
    // Now set up a notification to be called when a device is first matched by I/O Kit.
kr = IOServiceAddMatchingNotification(gNotifyPort,                  // notifyPort
                                      kIOFirstMatchNotification,    // notificationType
                                      matchingDict,                 // matching
                                      DeviceAdded,                  // callback
                                      NULL,                         // refCon
                                      &gAddedIter                   // notification
                                      );

当您获得 kIOSerialBSDServiceValue（在 DeviceAdded() 函数中）时，在 IOKit 树上向上遍历（使用 IORegistryEntryGetParentEntry）直到您找到您的 VID 和 PID。（请参阅我的第一个代码片段。）如果您找不到并且设备树已结束，则这不是您的设备。

IOKIT 使用 PID 和 VID 检测 USB 串行设备的 BSD(unix) 名称

IOKIT Detecting BSD(unix) name for USB Serial Device with PID and VID

macos

serial-port

usb

core-foundation

iokit