Forgot to add hid-linux.c

1 files changed, 798 insertions, 0 deletions

diff --git a/redist/hid-linux.c b/redist/hid-linux.c
new file mode 100644
index 0000000..5cc3bf2
--- /dev/null
+++ b/redist/hid-linux.c
@@ -0,0 +1,798 @@
+/*******************************************************
+ HIDAPI - Multi-Platform library for
+ communication with HID devices.
+
+ Alan Ott
+ Signal 11 Software
+
+ 8/22/2009
+ Linux Version - 6/2/2009
+
+ Copyright 2009, All Rights Reserved.
+
+ At the discretion of the user of this library,
+ this software may be licensed under the terms of the
+ GNU General Public License v3, a BSD-Style license, or the
+ original HIDAPI license as outlined in the LICENSE.txt,
+ LICENSE-gpl3.txt, LICENSE-bsd.txt, and LICENSE-orig.txt
+ files located at the root of the source distribution.
+ These files may also be found in the public source
+ code repository located at:
+        http://github.com/signal11/hidapi .
+********************************************************/
+
+/* C */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <locale.h>
+#include <errno.h>
+
+/* Unix */
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/utsname.h>
+#include <fcntl.h>
+#include <poll.h>
+
+/* Linux */
+#include <linux/hidraw.h>
+#include <linux/version.h>
+#include <linux/input.h>
+#include <libudev.h>
+
+#include "hidapi.h"
+
+/* Definitions from linux/hidraw.h. Since these are new, some distros
+   may not have header files which contain them. */
+#ifndef HIDIOCSFEATURE
+#define HIDIOCSFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x06, len)
+#endif
+#ifndef HIDIOCGFEATURE
+#define HIDIOCGFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x07, len)
+#endif
+
+
+/* USB HID device property names */
+const char *device_string_names[] = {
+	"manufacturer",
+	"product",
+	"serial",
+};
+
+/* Symbolic names for the properties above */
+enum device_string_id {
+	DEVICE_STRING_MANUFACTURER,
+	DEVICE_STRING_PRODUCT,
+	DEVICE_STRING_SERIAL,
+
+	DEVICE_STRING_COUNT,
+};
+
+struct hid_device_ {
+	int device_handle;
+	int blocking;
+	int uses_numbered_reports;
+};
+
+
+static __u32 kernel_version = 0;
+
+static __u32 detect_kernel_version(void)
+{
+	struct utsname name;
+	int major, minor, release;
+	int ret;
+
+	uname(&name);
+	ret = sscanf(name.release, "%d.%d.%d", &major, &minor, &release);
+	if (ret == 3) {
+		return KERNEL_VERSION(major, minor, release);
+	}
+
+	ret = sscanf(name.release, "%d.%d", &major, &minor);
+	if (ret == 2) {
+		return KERNEL_VERSION(major, minor, 0);
+	}
+
+	printf("Couldn't determine kernel version from version string \"%s\"\n", name.release);
+	return 0;
+}
+
+static hid_device *new_hid_device(void)
+{
+	hid_device *dev = calloc(1, sizeof(hid_device));
+	dev->device_handle = -1;
+	dev->blocking = 1;
+	dev->uses_numbered_reports = 0;
+
+	return dev;
+}
+
+
+/* The caller must free the returned string with free(). */
+static wchar_t *utf8_to_wchar_t(const char *utf8)
+{
+	wchar_t *ret = NULL;
+
+	if (utf8) {
+		size_t wlen = mbstowcs(NULL, utf8, 0);
+		if ((size_t) -1 == wlen) {
+			return wcsdup(L"");
+		}
+		ret = calloc(wlen+1, sizeof(wchar_t));
+		mbstowcs(ret, utf8, wlen+1);
+		ret[wlen] = 0x0000;
+	}
+
+	return ret;
+}
+
+/* Get an attribute value from a udev_device and return it as a whar_t
+   string. The returned string must be freed with free() when done.*/
+static wchar_t *copy_udev_string(struct udev_device *dev, const char *udev_name)
+{
+	return utf8_to_wchar_t(udev_device_get_sysattr_value(dev, udev_name));
+}
+
+/* uses_numbered_reports() returns 1 if report_descriptor describes a device
+   which contains numbered reports. */
+static int uses_numbered_reports(__u8 *report_descriptor, __u32 size) {
+	unsigned int i = 0;
+	int size_code;
+	int data_len, key_size;
+
+	while (i < size) {
+		int key = report_descriptor[i];
+
+		/* Check for the Report ID key */
+		if (key == 0x85/*Report ID*/) {
+			/* This device has a Report ID, which means it uses
+			   numbered reports. */
+			return 1;
+		}
+
+		//printf("key: %02hhx\n", key);
+
+		if ((key & 0xf0) == 0xf0) {
+			/* This is a Long Item. The next byte contains the
+			   length of the data section (value) for this key.
+			   See the HID specification, version 1.11, section
+			   6.2.2.3, titled "Long Items." */
+			if (i+1 < size)
+				data_len = report_descriptor[i+1];
+			else
+				data_len = 0; /* malformed report */
+			key_size = 3;
+		}
+		else {
+			/* This is a Short Item. The bottom two bits of the
+			   key contain the size code for the data section
+			   (value) for this key.  Refer to the HID
+			   specification, version 1.11, section 6.2.2.2,
+			   titled "Short Items." */
+			size_code = key & 0x3;
+			switch (size_code) {
+			case 0:
+			case 1:
+			case 2:
+				data_len = size_code;
+				break;
+			case 3:
+				data_len = 4;
+				break;
+			default:
+				/* Can't ever happen since size_code is & 0x3 */
+				data_len = 0;
+				break;
+			};
+			key_size = 1;
+		}
+
+		/* Skip over this key and it's associated data */
+		i += data_len + key_size;
+	}
+
+	/* Didn't find a Report ID key. Device doesn't use numbered reports. */
+	return 0;
+}
+
+/*
+ * The caller is responsible for free()ing the (newly-allocated) character
+ * strings pointed to by serial_number_utf8 and product_name_utf8 after use.
+ */
+static int
+parse_uevent_info(const char *uevent, int *bus_type,
+	unsigned short *vendor_id, unsigned short *product_id,
+	char **serial_number_utf8, char **product_name_utf8)
+{
+	char *tmp = strdup(uevent);
+	char *saveptr = NULL;
+	char *line;
+	char *key;
+	char *value;
+
+	int found_id = 0;
+	int found_serial = 0;
+	int found_name = 0;
+
+	line = strtok_r(tmp, "\n", &saveptr);
+	while (line != NULL) {
+		/* line: "KEY=value" */
+		key = line;
+		value = strchr(line, '=');
+		if (!value) {
+			goto next_line;
+		}
+		*value = '\0';
+		value++;
+
+		if (strcmp(key, "HID_ID") == 0) {
+			/**
+			 *        type vendor   product
+			 * HID_ID=0003:000005AC:00008242
+			 **/
+			int ret = sscanf(value, "%x:%hx:%hx", bus_type, vendor_id, product_id);
+			if (ret == 3) {
+				found_id = 1;
+			}
+		} else if (strcmp(key, "HID_NAME") == 0) {
+			/* The caller has to free the product name */
+			*product_name_utf8 = strdup(value);
+			found_name = 1;
+		} else if (strcmp(key, "HID_UNIQ") == 0) {
+			/* The caller has to free the serial number */
+			*serial_number_utf8 = strdup(value);
+			found_serial = 1;
+		}
+
+next_line:
+		line = strtok_r(NULL, "\n", &saveptr);
+	}
+
+	free(tmp);
+	return (found_id && found_name && found_serial);
+}
+
+
+static int get_device_string(hid_device *dev, enum device_string_id key, wchar_t *string, size_t maxlen)
+{
+	struct udev *udev;
+	struct udev_device *udev_dev, *parent, *hid_dev;
+	struct stat s;
+	int ret = -1;
+        char *serial_number_utf8 = NULL;
+        char *product_name_utf8 = NULL;
+
+	/* Create the udev object */
+	udev = udev_new();
+	if (!udev) {
+		printf("Can't create udev\n");
+		return -1;
+	}
+
+	/* Get the dev_t (major/minor numbers) from the file handle. */
+	ret = fstat(dev->device_handle, &s);
+	if (-1 == ret)
+		return ret;
+	/* Open a udev device from the dev_t. 'c' means character device. */
+	udev_dev = udev_device_new_from_devnum(udev, 'c', s.st_rdev);
+	if (udev_dev) {
+		hid_dev = udev_device_get_parent_with_subsystem_devtype(
+			udev_dev,
+			"hid",
+			NULL);
+		if (hid_dev) {
+			unsigned short dev_vid;
+			unsigned short dev_pid;
+			int bus_type;
+			size_t retm;
+
+			ret = parse_uevent_info(
+			           udev_device_get_sysattr_value(hid_dev, "uevent"),
+			           &bus_type,
+			           &dev_vid,
+			           &dev_pid,
+			           &serial_number_utf8,
+			           &product_name_utf8);
+
+			if (bus_type == BUS_BLUETOOTH) {
+				switch (key) {
+					case DEVICE_STRING_MANUFACTURER:
+						wcsncpy(string, L"", maxlen);
+						ret = 0;
+						break;
+					case DEVICE_STRING_PRODUCT:
+						retm = mbstowcs(string, product_name_utf8, maxlen);
+						ret = (retm == (size_t)-1)? -1: 0;
+						break;
+					case DEVICE_STRING_SERIAL:
+						retm = mbstowcs(string, serial_number_utf8, maxlen);
+						ret = (retm == (size_t)-1)? -1: 0;
+						break;
+					case DEVICE_STRING_COUNT:
+					default:
+						ret = -1;
+						break;
+				}
+			}
+			else {
+				/* This is a USB device. Find its parent USB Device node. */
+				parent = udev_device_get_parent_with_subsystem_devtype(
+					   udev_dev,
+					   "usb",
+					   "usb_device");
+				if (parent) {
+					const char *str;
+					const char *key_str = NULL;
+
+					if (key >= 0 && key < DEVICE_STRING_COUNT) {
+						key_str = device_string_names[key];
+					} else {
+						ret = -1;
+						goto end;
+					}
+
+					str = udev_device_get_sysattr_value(parent, key_str);
+					if (str) {
+						/* Convert the string from UTF-8 to wchar_t */
+						retm = mbstowcs(string, str, maxlen);
+						ret = (retm == (size_t)-1)? -1: 0;
+						goto end;
+					}
+				}
+			}
+		}
+	}
+
+end:
+        free(serial_number_utf8);
+        free(product_name_utf8);
+
+	udev_device_unref(udev_dev);
+	/* parent and hid_dev don't need to be (and can't be) unref'd.
+	   I'm not sure why, but they'll throw double-free() errors. */
+	udev_unref(udev);
+
+	return ret;
+}
+
+int HID_API_EXPORT hid_init(void)
+{
+	const char *locale;
+
+	/* Set the locale if it's not set. */
+	locale = setlocale(LC_CTYPE, NULL);
+	if (!locale)
+		setlocale(LC_CTYPE, "");
+
+	kernel_version = detect_kernel_version();
+
+	return 0;
+}
+
+int HID_API_EXPORT hid_exit(void)
+{
+	/* Nothing to do for this in the Linux/hidraw implementation. */
+	return 0;
+}
+
+
+struct hid_device_info  HID_API_EXPORT *hid_enumerate(unsigned short vendor_id, unsigned short product_id)
+{
+	struct udev *udev;
+	struct udev_enumerate *enumerate;
+	struct udev_list_entry *devices, *dev_list_entry;
+
+	struct hid_device_info *root = NULL; /* return object */
+	struct hid_device_info *cur_dev = NULL;
+	struct hid_device_info *prev_dev = NULL; /* previous device */
+
+	hid_init();
+
+	/* Create the udev object */
+	udev = udev_new();
+	if (!udev) {
+		printf("Can't create udev\n");
+		return NULL;
+	}
+
+	/* Create a list of the devices in the 'hidraw' subsystem. */
+	enumerate = udev_enumerate_new(udev);
+	udev_enumerate_add_match_subsystem(enumerate, "hidraw");
+	udev_enumerate_scan_devices(enumerate);
+	devices = udev_enumerate_get_list_entry(enumerate);
+	/* For each item, see if it matches the vid/pid, and if so
+	   create a udev_device record for it */
+	udev_list_entry_foreach(dev_list_entry, devices) {
+		const char *sysfs_path;
+		const char *dev_path;
+		const char *str;
+		struct udev_device *raw_dev; /* The device's hidraw udev node. */
+		struct udev_device *hid_dev; /* The device's HID udev node. */
+		struct udev_device *usb_dev; /* The device's USB udev node. */
+		struct udev_device *intf_dev; /* The device's interface (in the USB sense). */
+		unsigned short dev_vid;
+		unsigned short dev_pid;
+		char *serial_number_utf8 = NULL;
+		char *product_name_utf8 = NULL;
+		int bus_type;
+		int result;
+
+		/* Get the filename of the /sys entry for the device
+		   and create a udev_device object (dev) representing it */
+		sysfs_path = udev_list_entry_get_name(dev_list_entry);
+		raw_dev = udev_device_new_from_syspath(udev, sysfs_path);
+		dev_path = udev_device_get_devnode(raw_dev);
+
+		hid_dev = udev_device_get_parent_with_subsystem_devtype(
+			raw_dev,
+			"hid",
+			NULL);
+
+		if (!hid_dev) {
+			/* Unable to find parent hid device. */
+			goto next;
+		}
+
+		result = parse_uevent_info(
+			udev_device_get_sysattr_value(hid_dev, "uevent"),
+			&bus_type,
+			&dev_vid,
+			&dev_pid,
+			&serial_number_utf8,
+			&product_name_utf8);
+
+		if (!result) {
+			/* parse_uevent_info() failed for at least one field. */
+			goto next;
+		}
+
+		if (bus_type != BUS_USB && bus_type != BUS_BLUETOOTH) {
+			/* We only know how to handle USB and BT devices. */
+			goto next;
+		}
+
+		/* Check the VID/PID against the arguments */
+		if ((vendor_id == 0x0 || vendor_id == dev_vid) &&
+		    (product_id == 0x0 || product_id == dev_pid)) {
+			struct hid_device_info *tmp;
+
+			/* VID/PID match. Create the record. */
+			tmp = malloc(sizeof(struct hid_device_info));
+			if (cur_dev) {
+				cur_dev->next = tmp;
+			}
+			else {
+				root = tmp;
+			}
+			prev_dev = cur_dev;
+			cur_dev = tmp;
+
+			/* Fill out the record */
+			cur_dev->next = NULL;
+			cur_dev->path = dev_path? strdup(dev_path): NULL;
+
+			/* VID/PID */
+			cur_dev->vendor_id = dev_vid;
+			cur_dev->product_id = dev_pid;
+
+			/* Serial Number */
+			cur_dev->serial_number = utf8_to_wchar_t(serial_number_utf8);
+
+			/* Release Number */
+			cur_dev->release_number = 0x0;
+
+			/* Interface Number */
+			cur_dev->interface_number = -1;
+
+			switch (bus_type) {
+				case BUS_USB:
+					/* The device pointed to by raw_dev contains information about
+					   the hidraw device. In order to get information about the
+					   USB device, get the parent device with the
+					   subsystem/devtype pair of "usb"/"usb_device". This will
+					   be several levels up the tree, but the function will find
+					   it. */
+					usb_dev = udev_device_get_parent_with_subsystem_devtype(
+							raw_dev,
+							"usb",
+							"usb_device");
+
+					if (!usb_dev) {
+						/* Free this device */
+						free(cur_dev->serial_number);
+						free(cur_dev->path);
+						free(cur_dev);
+
+						/* Take it off the device list. */
+						if (prev_dev) {
+							prev_dev->next = NULL;
+							cur_dev = prev_dev;
+						}
+						else {
+							cur_dev = root = NULL;
+						}
+
+						goto next;
+					}
+
+					/* Manufacturer and Product strings */
+					cur_dev->manufacturer_string = copy_udev_string(usb_dev, device_string_names[DEVICE_STRING_MANUFACTURER]);
+					cur_dev->product_string = copy_udev_string(usb_dev, device_string_names[DEVICE_STRING_PRODUCT]);
+
+					/* Release Number */
+					str = udev_device_get_sysattr_value(usb_dev, "bcdDevice");
+					cur_dev->release_number = (str)? strtol(str, NULL, 16): 0x0;
+
+					/* Get a handle to the interface's udev node. */
+					intf_dev = udev_device_get_parent_with_subsystem_devtype(
+							raw_dev,
+							"usb",
+							"usb_interface");
+					if (intf_dev) {
+						str = udev_device_get_sysattr_value(intf_dev, "bInterfaceNumber");
+						cur_dev->interface_number = (str)? strtol(str, NULL, 16): -1;
+					}
+
+					break;
+
+				case BUS_BLUETOOTH:
+					/* Manufacturer and Product strings */
+					cur_dev->manufacturer_string = wcsdup(L"");
+					cur_dev->product_string = utf8_to_wchar_t(product_name_utf8);
+
+					break;
+
+				default:
+					/* Unknown device type - this should never happen, as we
+					 * check for USB and Bluetooth devices above */
+					break;
+			}
+		}
+
+	next:
+		free(serial_number_utf8);
+		free(product_name_utf8);
+		udev_device_unref(raw_dev);
+		/* hid_dev, usb_dev and intf_dev don't need to be (and can't be)
+		   unref()d.  It will cause a double-free() error.  I'm not
+		   sure why.  */
+	}
+	/* Free the enumerator and udev objects. */
+	udev_enumerate_unref(enumerate);
+	udev_unref(udev);
+
+	return root;
+}
+
+void  HID_API_EXPORT hid_free_enumeration(struct hid_device_info *devs)
+{
+	struct hid_device_info *d = devs;
+	while (d) {
+		struct hid_device_info *next = d->next;
+		free(d->path);
+		free(d->serial_number);
+		free(d->manufacturer_string);
+		free(d->product_string);
+		free(d);
+		d = next;
+	}
+}
+
+hid_device * hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number)
+{
+	struct hid_device_info *devs, *cur_dev;
+	const char *path_to_open = NULL;
+	hid_device *handle = NULL;
+
+	devs = hid_enumerate(vendor_id, product_id);
+	cur_dev = devs;
+	while (cur_dev) {
+		if (cur_dev->vendor_id == vendor_id &&
+		    cur_dev->product_id == product_id) {
+			if (serial_number) {
+				if (wcscmp(serial_number, cur_dev->serial_number) == 0) {
+					path_to_open = cur_dev->path;
+					break;
+				}
+			}
+			else {
+				path_to_open = cur_dev->path;
+				break;
+			}
+		}
+		cur_dev = cur_dev->next;
+	}
+
+	if (path_to_open) {
+		/* Open the device */
+		handle = hid_open_path(path_to_open);
+	}
+
+	hid_free_enumeration(devs);
+
+	return handle;
+}
+
+hid_device * HID_API_EXPORT hid_open_path(const char *path)
+{
+	hid_device *dev = NULL;
+
+	hid_init();
+
+	dev = new_hid_device();
+
+	/* OPEN HERE */
+	dev->device_handle = open(path, O_RDWR);
+
+	/* If we have a good handle, return it. */
+	if (dev->device_handle > 0) {
+
+		/* Get the report descriptor */
+		int res, desc_size = 0;
+		struct hidraw_report_descriptor rpt_desc;
+
+		memset(&rpt_desc, 0x0, sizeof(rpt_desc));
+
+		/* Get Report Descriptor Size */
+		res = ioctl(dev->device_handle, HIDIOCGRDESCSIZE, &desc_size);
+		if (res < 0)
+			perror("HIDIOCGRDESCSIZE");
+
+
+		/* Get Report Descriptor */
+		rpt_desc.size = desc_size;
+		res = ioctl(dev->device_handle, HIDIOCGRDESC, &rpt_desc);
+		if (res < 0) {
+			perror("HIDIOCGRDESC");
+		} else {
+			/* Determine if this device uses numbered reports. */
+			dev->uses_numbered_reports =
+				uses_numbered_reports(rpt_desc.value,
+				                      rpt_desc.size);
+		}
+
+		return dev;
+	}
+	else {
+		/* Unable to open any devices. */
+		free(dev);
+		return NULL;
+	}
+}
+
+
+int HID_API_EXPORT hid_write(hid_device *dev, const unsigned char *data, size_t length)
+{
+	int bytes_written;
+
+	bytes_written = write(dev->device_handle, data, length);
+
+	return bytes_written;
+}
+
+
+int HID_API_EXPORT hid_read_timeout(hid_device *dev, unsigned char *data, size_t length, int milliseconds)
+{
+	int bytes_read;
+
+	if (milliseconds >= 0) {
+		/* Milliseconds is either 0 (non-blocking) or > 0 (contains
+		   a valid timeout). In both cases we want to call poll()
+		   and wait for data to arrive.  Don't rely on non-blocking
+		   operation (O_NONBLOCK) since some kernels don't seem to
+		   properly report device disconnection through read() when
+		   in non-blocking mode.  */
+		int ret;
+		struct pollfd fds;
+
+		fds.fd = dev->device_handle;
+		fds.events = POLLIN;
+		fds.revents = 0;
+		ret = poll(&fds, 1, milliseconds);
+		if (ret == -1 || ret == 0) {
+			/* Error or timeout */
+			return ret;
+		}
+		else {
+			/* Check for errors on the file descriptor. This will
+			   indicate a device disconnection. */
+			if (fds.revents & (POLLERR | POLLHUP | POLLNVAL))
+				return -1;
+		}
+	}
+
+	bytes_read = read(dev->device_handle, data, length);
+	if (bytes_read < 0 && (errno == EAGAIN || errno == EINPROGRESS))
+		bytes_read = 0;
+
+	if (bytes_read >= 0 &&
+	    kernel_version != 0 &&
+	    kernel_version < KERNEL_VERSION(2,6,34) &&
+	    dev->uses_numbered_reports) {
+		/* Work around a kernel bug. Chop off the first byte. */
+		memmove(data, data+1, bytes_read);
+		bytes_read--;
+	}
+
+	return bytes_read;
+}
+
+int HID_API_EXPORT hid_read(hid_device *dev, unsigned char *data, size_t length)
+{
+	return hid_read_timeout(dev, data, length, (dev->blocking)? -1: 0);
+}
+
+int HID_API_EXPORT hid_set_nonblocking(hid_device *dev, int nonblock)
+{
+	/* Do all non-blocking in userspace using poll(), since it looks
+	   like there's a bug in the kernel in some versions where
+	   read() will not return -1 on disconnection of the USB device */
+
+	dev->blocking = !nonblock;
+	return 0; /* Success */
+}
+
+
+int HID_API_EXPORT hid_send_feature_report(hid_device *dev, const unsigned char *data, size_t length)
+{
+	int res;
+
+	res = ioctl(dev->device_handle, HIDIOCSFEATURE(length), data);
+	if (res < 0)
+		perror("ioctl (SFEATURE)");
+
+	return res;
+}
+
+int HID_API_EXPORT hid_get_feature_report(hid_device *dev, unsigned char *data, size_t length)
+{
+	int res;
+
+	res = ioctl(dev->device_handle, HIDIOCGFEATURE(length), data);
+	if (res < 0)
+		perror("ioctl (GFEATURE)");
+
+
+	return res;
+}
+
+
+void HID_API_EXPORT hid_close(hid_device *dev)
+{
+	if (!dev)
+		return;
+	close(dev->device_handle);
+	free(dev);
+}
+
+
+int HID_API_EXPORT_CALL hid_get_manufacturer_string(hid_device *dev, wchar_t *string, size_t maxlen)
+{
+	return get_device_string(dev, DEVICE_STRING_MANUFACTURER, string, maxlen);
+}
+
+int HID_API_EXPORT_CALL hid_get_product_string(hid_device *dev, wchar_t *string, size_t maxlen)
+{
+	return get_device_string(dev, DEVICE_STRING_PRODUCT, string, maxlen);
+}
+
+int HID_API_EXPORT_CALL hid_get_serial_number_string(hid_device *dev, wchar_t *string, size_t maxlen)
+{
+	return get_device_string(dev, DEVICE_STRING_SERIAL, string, maxlen);
+}
+
+int HID_API_EXPORT_CALL hid_get_indexed_string(hid_device *dev, int string_index, wchar_t *string, size_t maxlen)
+{
+	return -1;
+}
+
+
+HID_API_EXPORT const wchar_t * HID_API_CALL  hid_error(hid_device *dev)
+{
+	return NULL;
+}
+