你好,我刚开始接触xCode和Mac OS编程,在使用USB和串口设备时有些迷茫。
我正在尝试编写一个max/msp外部程序,用于列出与特定产品ID、厂商ID和名称匹配的USB设备的串行BSD路径。
到目前为止,我得到了一个可以列出串行BSD路径的程序:
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <paths.h>
#include <termios.h>
#include <sysexits.h>
#include <sys/param.h>
#include <sys/select.h>
#include <sys/time.h>
#include <time.h>
#include <CoreFoundation/CoreFoundation.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/serial/IOSerialKeys.h>
#include <IOKit/serial/ioss.h>
#include <IOKit/IOBSD.h>
// Function prototypes
static kern_return_t findModems(io_iterator_t *matchingServices);
static kern_return_t getModemPath(io_iterator_t serialPortIterator, char *bsdPath, CFIndex maxPathSize);
// Returns an iterator across all known modems. Caller is responsible for
// releasing the iterator when iteration is complete.
static kern_return_t findModems(io_iterator_t *matchingServices)
{
kern_return_t kernResult;
CFMutableDictionaryRef classesToMatch;
// Serial devices are instances of class IOSerialBSDClient.
// Create a matching dictionary to find those instances.
classesToMatch = IOServiceMatching(kIOSerialBSDServiceValue);
if (classesToMatch == NULL) {
printf("IOServiceMatching returned a NULL dictionary.\n");
}
else {
// Look for devices that claim to be modems.
CFDictionarySetValue(classesToMatch,
CFSTR(kIOSerialBSDTypeKey),
CFSTR(kIOSerialBSDAllTypes));
}
// Get an iterator across all matching devices.
kernResult = IOServiceGetMatchingServices(kIOMasterPortDefault, classesToMatch, matchingServices);
if (KERN_SUCCESS != kernResult) {
printf("IOServiceGetMatchingServices returned %d\n", kernResult);
goto exit;
}
exit:
return kernResult;
}
static kern_return_t getModemPath(io_iterator_t serialPortIterator, char *bsdPath, CFIndex maxPathSize)
{
io_object_t modemService;
kern_return_t kernResult = KERN_FAILURE;
Boolean modemFound = false;
// Initialize the returned path
*bsdPath = '\0';
// Iterate across all modems found. In this example, we bail after finding the first modem.
while ((modemService = IOIteratorNext(serialPortIterator))) {
CFTypeRef bsdPathAsCFString;
bsdPathAsCFString = IORegistryEntryCreateCFProperty(modemService,
CFSTR(kIOCalloutDeviceKey),
kCFAllocatorDefault,
0);
if (bsdPathAsCFString) {
Boolean result;
result = CFStringGetCString(bsdPathAsCFString,
bsdPath,
maxPathSize,
kCFStringEncodingUTF8);
CFRelease(bsdPathAsCFString);
if (result) {
printf("Modem found with BSD path: %s", bsdPath);
modemFound = true;
kernResult = KERN_SUCCESS;
}
}
printf("\n");
// Release the io_service_t now that we are done with it.
(void) IOObjectRelease(modemService);
}
return kernResult;
}
int main(int argc, const char * argv[])
{
kern_return_t kernResult;
io_iterator_t serialPortIterator;
char bsdPath[MAXPATHLEN];
kernResult = findModems(&serialPortIterator);
if (KERN_SUCCESS != kernResult) {
printf("No modems were found.\n");
}
kernResult = getModemPath(serialPortIterator, bsdPath, sizeof(bsdPath));
if (KERN_SUCCESS != kernResult) {
printf("Could not get path for modem.\n");
}
IOObjectRelease(serialPortIterator);
return EX_OK;
}
还有另一段代码,用于搜索特定ID的USB设备:
#include <CoreFoundation/CoreFoundation.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/IOMessage.h>
#include <IOKit/IOCFPlugIn.h>
#include <IOKit/usb/IOUSBLib.h>
// Change these two constants to match your device's idVendor and idProduct.
// Or, just pass your idVendor and idProduct as command line arguments when running this sample.
#define kMyVendorID 0x04D8
#define kMyProductID 0x000A
typedef struct MyPrivateData {
io_object_t notification;
IOUSBDeviceInterface **deviceInterface;
CFStringRef deviceName;
unsigned int locationID;
} MyPrivateData;
static IONotificationPortRef gNotifyPort;
static io_iterator_t gAddedIter;
static CFRunLoopRef gRunLoop;
//================================================================================================
//
// DeviceNotification
//
// This routine will get called whenever any kIOGeneralInterest notification happens. We are
// interested in the kIOMessageServiceIsTerminated message so that's what we look for. Other
// messages are defined in IOMessage.h.
//
//================================================================================================
void DeviceNotification(void *refCon, io_service_t service, natural_t messageType, void *messageArgument)
{
kern_return_t kr;
MyPrivateData *privateDataRef = (MyPrivateData *) refCon;
if (messageType == kIOMessageServiceIsTerminated) {
fprintf(stderr, "Device removed.\n");
// Dump our private data to stderr just to see what it looks like.
fprintf(stderr, "privateDataRef->deviceName: ");
CFShow(privateDataRef->deviceName);
fprintf(stderr, "privateDataRef->locationID: 0x%x.\n\n", privateDataRef->locationID);
// Free the data we're no longer using now that the device is going away
CFRelease(privateDataRef->deviceName);
if (privateDataRef->deviceInterface) {
kr = (*privateDataRef->deviceInterface)->Release(privateDataRef->deviceInterface);
}
kr = IOObjectRelease(privateDataRef->notification);
free(privateDataRef);
}
}
//================================================================================================
//
// DeviceAdded
//
// This routine is the callback for our IOServiceAddMatchingNotification. When we get called
// we will look at all the devices that were added and we will:
//
// 1. Create some private data to relate to each device (in this case we use the service's name
// and the location ID of the device
// 2. Submit an IOServiceAddInterestNotification of type kIOGeneralInterest for this device,
// using the refCon field to store a pointer to our private data. When we get called with
// this interest notification, we can grab the refCon and access our private data.
//
//================================================================================================
void DeviceAdded(void *refCon, io_iterator_t iterator)
{
kern_return_t kr;
io_service_t usbDevice;
IOCFPlugInInterface **plugInInterface = NULL;
SInt32 score;
HRESULT res;
while ((usbDevice = IOIteratorNext(iterator))) {
io_name_t deviceName;
CFStringRef deviceNameAsCFString;
MyPrivateData *privateDataRef = NULL;
unsigned int locationID;
printf("Device added.\n");
// Add some app-specific information about this device.
// Create a buffer to hold the data.
privateDataRef = malloc(sizeof(MyPrivateData));
bzero(privateDataRef, sizeof(MyPrivateData));
// Get the USB device's name.
kr = IORegistryEntryGetName(usbDevice, deviceName);
if (KERN_SUCCESS != kr) {
deviceName[0] = '\0';
}
deviceNameAsCFString = CFStringCreateWithCString(kCFAllocatorDefault, deviceName,
kCFStringEncodingASCII);
// Dump our data to stderr just to see what it looks like.
fprintf(stderr, "deviceName: ");
CFShow(deviceNameAsCFString);
// Save the device's name to our private data.
privateDataRef->deviceName = deviceNameAsCFString;
// Now, get the locationID of this device. In order to do this, we need to create an IOUSBDeviceInterface
// for our device. This will create the necessary connections between our userland application and the
// kernel object for the USB Device.
kr = IOCreatePlugInInterfaceForService(usbDevice, kIOUSBDeviceUserClientTypeID, kIOCFPlugInInterfaceID,
&plugInInterface, &score);
if ((kIOReturnSuccess != kr) || !plugInInterface) {
fprintf(stderr, "IOCreatePlugInInterfaceForService returned 0x%08x.\n", kr);
continue;
}
// Use the plugin interface to retrieve the device interface.
res = (*plugInInterface)->QueryInterface(plugInInterface, CFUUIDGetUUIDBytes(kIOUSBDeviceInterfaceID),
(LPVOID*) &privateDataRef->deviceInterface);
// Now done with the plugin interface.
(*plugInInterface)->Release(plugInInterface);
if (res || privateDataRef->deviceInterface == NULL) {
fprintf(stderr, "QueryInterface returned %d.\n", (int) res);
continue;
}
// Now that we have the IOUSBDeviceInterface, we can call the routines in IOUSBLib.h.
// In this case, fetch the locationID. The locationID uniquely identifies the device
// and will remain the same, even across reboots, so long as the bus topology doesn't change.
kr = (*privateDataRef->deviceInterface)->GetLocationID(privateDataRef->deviceInterface, &locationID);
if (KERN_SUCCESS != kr) {
fprintf(stderr, "GetLocationID returned 0x%08x.\n", kr);
continue;
}
else {
fprintf(stderr, "Location ID: 0x%x\n\n", locationID);
}
privateDataRef->locationID = locationID;
// Register for an interest notification of this device being removed. Use a reference to our
// private data as the refCon which will be passed to the notification callback.
kr = IOServiceAddInterestNotification(gNotifyPort, // notifyPort
usbDevice, // service
kIOGeneralInterest, // interestType
DeviceNotification, // callback
privateDataRef, // refCon
&(privateDataRef->notification) // notification
);
if (KERN_SUCCESS != kr) {
printf("IOServiceAddInterestNotification returned 0x%08x.\n", kr);
}
// Done with this USB device; release the reference added by IOIteratorNext
kr = IOObjectRelease(usbDevice);
}
}
//================================================================================================
//
// SignalHandler
//
// This routine will get called when we interrupt the program (usually with a Ctrl-C from the
// command line).
//
//================================================================================================
void SignalHandler(int sigraised)
{
fprintf(stderr, "\nInterrupted.\n");
exit(0);
}
//================================================================================================
// main
//================================================================================================
int main(int argc, const char *argv[])
{
CFMutableDictionaryRef matchingDict;
CFRunLoopSourceRef runLoopSource;
CFNumberRef numberRef;
kern_return_t kr;
long usbVendor = kMyVendorID;
long usbProduct = kMyProductID;
sig_t oldHandler;
// Set up a signal handler so we can clean up when we're interrupted from the command line
// Otherwise we stay in our run loop forever.
oldHandler = signal(SIGINT, SignalHandler);
if (oldHandler == SIG_ERR) {
fprintf(stderr, "Could not establish new signal handler.");
}
fprintf(stderr, "Looking for devices matching vendor ID=%ld and product ID=%ld.\n", usbVendor, usbProduct);
// Set up the matching criteria for the devices we're interested in. The matching criteria needs to follow
// the same rules as kernel drivers: mainly it needs to follow the USB Common Class Specification, pp. 6-7.
// See also Technical Q&A QA1076 "Tips on USB driver matching on Mac OS X"
// <http://developer.apple.com/qa/qa2001/qa1076.html>.
// One exception is that you can use the matching dictionary "as is", i.e. without adding any matching
// criteria to it and it will match every IOUSBDevice in the system. IOServiceAddMatchingNotification will
// consume this dictionary reference, so there is no need to release it later on.
matchingDict = IOServiceMatching(kIOUSBDeviceClassName); // Interested in instances of class
// IOUSBDevice and its subclasses
if (matchingDict == NULL) {
fprintf(stderr, "IOServiceMatching returned NULL.\n");
return -1;
}
// We are interested in all USB devices (as opposed to USB interfaces). The Common Class Specification
// tells us that we need to specify the idVendor, idProduct, and bcdDevice fields, or, if we're not interested
// in particular bcdDevices, just the idVendor and idProduct. Note that if we were trying to match an
// IOUSBInterface, we would need to set more values in the matching dictionary (e.g. idVendor, idProduct,
// bInterfaceNumber and bConfigurationValue.
// 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);
numberRef = NULL;
// Create a notification port and add its run loop event source to our run loop
// This is how async notifications get set up.
gNotifyPort = IONotificationPortCreate(kIOMasterPortDefault);
runLoopSource = IONotificationPortGetRunLoopSource(gNotifyPort);
gRunLoop = CFRunLoopGetCurrent();
CFRunLoopAddSource(gRunLoop, runLoopSource, kCFRunLoopDefaultMode);
// 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
);
// Iterate once to get already-present devices and arm the notification
DeviceAdded(NULL, gAddedIter);
// Start the run loop. Now we'll receive notifications.
fprintf(stderr, "Starting run loop.\n\n");
CFRunLoopRun();
// We should never get here
fprintf(stderr, "Unexpectedly back from CFRunLoopRun()!\n");
return 0;
}
但我无法成功将两者合并。非常感激任何帮助。