1 /*******************************************************
2  HIDAPI - Multi-Platform library for
3  communication with HID devices.
4 
5  Alan Ott
6  Signal 11 Software
7 
8  8/22/2009
9 
10  Copyright 2009, All Rights Reserved.
11 
12  At the discretion of the user of this library,
13  this software may be licensed under the terms of the
14  GNU General Public License v3, a BSD-Style license, or the
15  original HIDAPI license as outlined in the LICENSE.txt,
16  LICENSE-gpl3.txt, LICENSE-bsd.txt, and LICENSE-orig.txt
17  files located at the root of the source distribution.
18  These files may also be found in the public source
19  code repository located at:
20         http://github.com/signal11/hidapi .
21 ********************************************************/
22 
23 /** @file
24  * @defgroup API hidapi API
25  */
26 
27 #ifndef HIDAPI_H__
28 #define HIDAPI_H__
29 
30 #include <wchar.h>
31 
32 #ifdef _WIN32
33       #define HID_API_EXPORT __declspec(dllexport)
34       #define HID_API_CALL
35 #else
36       #define HID_API_EXPORT /**< API export macro */
37       #define HID_API_CALL /**< API call macro */
38 #endif
39 
40 #define HID_API_EXPORT_CALL HID_API_EXPORT HID_API_CALL /**< API export and call macro*/
41 
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
45 		struct hid_device_;
46 		typedef struct hid_device_ hid_device; /**< opaque hidapi structure */
47 
48 		/** hidapi info structure */
49 		struct hid_device_info {
50 			/** Platform-specific device path */
51 			char *path;
52 			/** Device Vendor ID */
53 			unsigned short vendor_id;
54 			/** Device Product ID */
55 			unsigned short product_id;
56 			/** Serial Number */
57 			wchar_t *serial_number;
58 			/** Device Release Number in binary-coded decimal,
59 			    also known as Device Version Number */
60 			unsigned short release_number;
61 			/** Manufacturer String */
62 			wchar_t *manufacturer_string;
63 			/** Product string */
64 			wchar_t *product_string;
65 			/** Usage Page for this Device/Interface
66 			    (Windows/Mac only). */
67 			unsigned short usage_page;
68 			/** Usage for this Device/Interface
69 			    (Windows/Mac only).*/
70 			unsigned short usage;
71 			/** The USB interface which this logical device
72 			    represents. Valid on both Linux implementations
73 			    in all cases, and valid on the Windows implementation
74 			    only if the device contains more than one interface. */
75 			int interface_number;
76 
77 			/** Pointer to the next device */
78 			struct hid_device_info *next;
79 		};
80 
81 
82 		/** @brief Initialize the HIDAPI library.
83 
84 			This function initializes the HIDAPI library. Calling it is not
85 			strictly necessary, as it will be called automatically by
86 			hid_enumerate() and any of the hid_open_*() functions if it is
87 			needed.  This function should be called at the beginning of
88 			execution however, if there is a chance of HIDAPI handles
89 			being opened by different threads simultaneously.
90 
91 			@ingroup API
92 
93 			@returns
94 				This function returns 0 on success and -1 on error.
95 		*/
96 		int HID_API_EXPORT HID_API_CALL hid_init(void);
97 
98 		/** @brief Finalize the HIDAPI library.
99 
100 			This function frees all of the static data associated with
101 			HIDAPI. It should be called at the end of execution to avoid
102 			memory leaks.
103 
104 			@ingroup API
105 
106 		    @returns
107 				This function returns 0 on success and -1 on error.
108 		*/
109 		int HID_API_EXPORT HID_API_CALL hid_exit(void);
110 
111 		/** @brief Enumerate the HID Devices.
112 
113 			This function returns a linked list of all the HID devices
114 			attached to the system which match vendor_id and product_id.
115 			If @p vendor_id is set to 0 then any vendor matches.
116 			If @p product_id is set to 0 then any product matches.
117 			If @p vendor_id and @p product_id are both set to 0, then
118 			all HID devices will be returned.
119 
120 			@ingroup API
121 			@param vendor_id The Vendor ID (VID) of the types of device
122 				to open.
123 			@param product_id The Product ID (PID) of the types of
124 				device to open.
125 
126 		    @returns
127 		    	This function returns a pointer to a linked list of type
128 		    	struct #hid_device, containing information about the HID devices
129 		    	attached to the system, or NULL in the case of failure. Free
130 		    	this linked list by calling hid_free_enumeration().
131 		*/
132 		struct hid_device_info HID_API_EXPORT * HID_API_CALL hid_enumerate(unsigned short vendor_id, unsigned short product_id);
133 
134 		/** @brief Free an enumeration Linked List
135 
136 		    This function frees a linked list created by hid_enumerate().
137 
138 			@ingroup API
139 		    @param devs Pointer to a list of struct_device returned from
140 		    	      hid_enumerate().
141 		*/
142 		void  HID_API_EXPORT HID_API_CALL hid_free_enumeration(struct hid_device_info *devs);
143 
144 		/** @brief Open a HID device using a Vendor ID (VID), Product ID
145 			(PID) and optionally a serial number.
146 
147 			If @p serial_number is NULL, the first device with the
148 			specified VID and PID is opened.
149 
150 			@ingroup API
151 			@param vendor_id The Vendor ID (VID) of the device to open.
152 			@param product_id The Product ID (PID) of the device to open.
153 			@param serial_number The Serial Number of the device to open
154 				               (Optionally NULL).
155 
156 			@returns
157 				This function returns a pointer to a #hid_device object on
158 				success or NULL on failure.
159 		*/
160 		HID_API_EXPORT hid_device * HID_API_CALL hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number);
161 
162 		/** @brief Open a HID device by its path name.
163 
164 			The path name be determined by calling hid_enumerate(), or a
165 			platform-specific path name can be used (eg: /dev/hidraw0 on
166 			Linux).
167 
168 			@ingroup API
169 		    @param path The path name of the device to open
170 
171 			@returns
172 				This function returns a pointer to a #hid_device object on
173 				success or NULL on failure.
174 		*/
175 		HID_API_EXPORT hid_device * HID_API_CALL hid_open_path(const char *path);
176 
177 		/** @brief Write an Output report to a HID device.
178 
179 			The first byte of @p data[] must contain the Report ID. For
180 			devices which only support a single report, this must be set
181 			to 0x0. The remaining bytes contain the report data. Since
182 			the Report ID is mandatory, calls to hid_write() will always
183 			contain one more byte than the report contains. For example,
184 			if a hid report is 16 bytes long, 17 bytes must be passed to
185 			hid_write(), the Report ID (or 0x0, for devices with a
186 			single report), followed by the report data (16 bytes). In
187 			this example, the length passed in would be 17.
188 
189 			hid_write() will send the data on the first OUT endpoint, if
190 			one exists. If it does not, it will send the data through
191 			the Control Endpoint (Endpoint 0).
192 
193 			@ingroup API
194 			@param device A device handle returned from hid_open().
195 			@param data The data to send, including the report number as
196 				the first byte.
197 			@param length The length in bytes of the data to send.
198 
199 			@returns
200 				This function returns the actual number of bytes written and
201 				-1 on error.
202 		*/
203 		int  HID_API_EXPORT HID_API_CALL hid_write(hid_device *device, const unsigned char *data, size_t length);
204 
205 		/** @brief Read an Input report from a HID device with timeout.
206 
207 			Input reports are returned
208 			to the host through the INTERRUPT IN endpoint. The first byte will
209 			contain the Report number if the device uses numbered reports.
210 
211 			@ingroup API
212 			@param device A device handle returned from hid_open().
213 			@param data A buffer to put the read data into.
214 			@param length The number of bytes to read. For devices with
215 				multiple reports, make sure to read an extra byte for
216 				the report number.
217 			@param milliseconds timeout in milliseconds or -1 for blocking wait.
218 
219 			@returns
220 				This function returns the actual number of bytes read and
221 				-1 on error. If no packet was available to be read within
222 				the timeout period, this function returns 0.
223 		*/
224 		int HID_API_EXPORT HID_API_CALL hid_read_timeout(hid_device *dev, unsigned char *data, size_t length, int milliseconds);
225 
226 		/** @brief Read an Input report from a HID device.
227 
228 			Input reports are returned
229 		    to the host through the INTERRUPT IN endpoint. The first byte will
230 			contain the Report number if the device uses numbered reports.
231 
232 			@ingroup API
233 			@param device A device handle returned from hid_open().
234 			@param data A buffer to put the read data into.
235 			@param length The number of bytes to read. For devices with
236 				multiple reports, make sure to read an extra byte for
237 				the report number.
238 
239 			@returns
240 				This function returns the actual number of bytes read and
241 				-1 on error. If no packet was available to be read and
242 				the handle is in non-blocking mode, this function returns 0.
243 		*/
244 		int  HID_API_EXPORT HID_API_CALL hid_read(hid_device *device, unsigned char *data, size_t length);
245 
246 		/** @brief Set the device handle to be non-blocking.
247 
248 			In non-blocking mode calls to hid_read() will return
249 			immediately with a value of 0 if there is no data to be
250 			read. In blocking mode, hid_read() will wait (block) until
251 			there is data to read before returning.
252 
253 			Nonblocking can be turned on and off at any time.
254 
255 			@ingroup API
256 			@param device A device handle returned from hid_open().
257 			@param nonblock enable or not the nonblocking reads
258 			 - 1 to enable nonblocking
259 			 - 0 to disable nonblocking.
260 
261 			@returns
262 				This function returns 0 on success and -1 on error.
263 		*/
264 		int  HID_API_EXPORT HID_API_CALL hid_set_nonblocking(hid_device *device, int nonblock);
265 
266 		/** @brief Send a Feature report to the device.
267 
268 			Feature reports are sent over the Control endpoint as a
269 			Set_Report transfer.  The first byte of @p data[] must
270 			contain the Report ID. For devices which only support a
271 			single report, this must be set to 0x0. The remaining bytes
272 			contain the report data. Since the Report ID is mandatory,
273 			calls to hid_send_feature_report() will always contain one
274 			more byte than the report contains. For example, if a hid
275 			report is 16 bytes long, 17 bytes must be passed to
276 			hid_send_feature_report(): the Report ID (or 0x0, for
277 			devices which do not use numbered reports), followed by the
278 			report data (16 bytes). In this example, the length passed
279 			in would be 17.
280 
281 			@ingroup API
282 			@param device A device handle returned from hid_open().
283 			@param data The data to send, including the report number as
284 				the first byte.
285 			@param length The length in bytes of the data to send, including
286 				the report number.
287 
288 			@returns
289 				This function returns the actual number of bytes written and
290 				-1 on error.
291 		*/
292 		int HID_API_EXPORT HID_API_CALL hid_send_feature_report(hid_device *device, const unsigned char *data, size_t length);
293 
294 		/** @brief Get a feature report from a HID device.
295 
296 			Set the first byte of @p data[] to the Report ID of the
297 			report to be read.  Make sure to allow space for this
298 			extra byte in @p data[]. Upon return, the first byte will
299 			still contain the Report ID, and the report data will
300 			start in data[1].
301 
302 			@ingroup API
303 			@param device A device handle returned from hid_open().
304 			@param data A buffer to put the read data into, including
305 				the Report ID. Set the first byte of @p data[] to the
306 				Report ID of the report to be read, or set it to zero
307 				if your device does not use numbered reports.
308 			@param length The number of bytes to read, including an
309 				extra byte for the report ID. The buffer can be longer
310 				than the actual report.
311 
312 			@returns
313 				This function returns the number of bytes read plus
314 				one for the report ID (which is still in the first
315 				byte), or -1 on error.
316 		*/
317 		int HID_API_EXPORT HID_API_CALL hid_get_feature_report(hid_device *device, unsigned char *data, size_t length);
318 
319 		/** @brief Close a HID device.
320 
321 			@ingroup API
322 			@param device A device handle returned from hid_open().
323 		*/
324 		void HID_API_EXPORT HID_API_CALL hid_close(hid_device *device);
325 
326 		/** @brief Get The Manufacturer String from a HID device.
327 
328 			@ingroup API
329 			@param device A device handle returned from hid_open().
330 			@param string A wide string buffer to put the data into.
331 			@param maxlen The length of the buffer in multiples of wchar_t.
332 
333 			@returns
334 				This function returns 0 on success and -1 on error.
335 		*/
336 		int HID_API_EXPORT_CALL hid_get_manufacturer_string(hid_device *device, wchar_t *string, size_t maxlen);
337 
338 		/** @brief Get The Product String from a HID device.
339 
340 			@ingroup API
341 			@param device A device handle returned from hid_open().
342 			@param string A wide string buffer to put the data into.
343 			@param maxlen The length of the buffer in multiples of wchar_t.
344 
345 			@returns
346 				This function returns 0 on success and -1 on error.
347 		*/
348 		int HID_API_EXPORT_CALL hid_get_product_string(hid_device *device, wchar_t *string, size_t maxlen);
349 
350 		/** @brief Get The Serial Number String from a HID device.
351 
352 			@ingroup API
353 			@param device A device handle returned from hid_open().
354 			@param string A wide string buffer to put the data into.
355 			@param maxlen The length of the buffer in multiples of wchar_t.
356 
357 			@returns
358 				This function returns 0 on success and -1 on error.
359 		*/
360 		int HID_API_EXPORT_CALL hid_get_serial_number_string(hid_device *device, wchar_t *string, size_t maxlen);
361 
362 		/** @brief Get a string from a HID device, based on its string index.
363 
364 			@ingroup API
365 			@param device A device handle returned from hid_open().
366 			@param string_index The index of the string to get.
367 			@param string A wide string buffer to put the data into.
368 			@param maxlen The length of the buffer in multiples of wchar_t.
369 
370 			@returns
371 				This function returns 0 on success and -1 on error.
372 		*/
373 		int HID_API_EXPORT_CALL hid_get_indexed_string(hid_device *device, int string_index, wchar_t *string, size_t maxlen);
374 
375 		/** @brief Get a string describing the last error which occurred.
376 
377 			@ingroup API
378 			@param device A device handle returned from hid_open().
379 
380 			@returns
381 				This function returns a string containing the last error
382 				which occurred or NULL if none has occurred.
383 		*/
384 		HID_API_EXPORT const wchar_t* HID_API_CALL hid_error(hid_device *device);
385 
386 #ifdef __cplusplus
387 }
388 #endif
389 
390 #endif
391 
392