1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20*/
21
22/* WIKI CATEGORY: HIDAPI */
23
24/**
25 * # CategoryHIDAPI
26 *
27 * Header file for SDL HIDAPI functions.
28 *
29 * This is an adaptation of the original HIDAPI interface by Alan Ott, and
30 * includes source code licensed under the following license:
31 *
32 * ```
33 * HIDAPI - Multi-Platform library for
34 * communication with HID devices.
35 *
36 * Copyright 2009, Alan Ott, Signal 11 Software.
37 * All Rights Reserved.
38 *
39 * This software may be used by anyone for any reason so
40 * long as the copyright notice in the source files
41 * remains intact.
42 * ```
43 *
44 * (Note that this license is the same as item three of SDL's zlib license, so
45 * it adds no new requirements on the user.)
46 *
47 * If you would like a version of SDL without this code, you can build SDL
48 * with SDL_HIDAPI_DISABLED defined to 1. You might want to do this for
49 * example on iOS or tvOS to avoid a dependency on the CoreBluetooth
50 * framework.
51 */
52
53#ifndef SDL_hidapi_h_
54#define SDL_hidapi_h_
55
56#include <SDL3/SDL_stdinc.h>
57#include <SDL3/SDL_error.h>
58
59#include <SDL3/SDL_begin_code.h>
60/* Set up for C function definitions, even when using C++ */
61#ifdef __cplusplus
62extern "C" {
63#endif
64
65/**
66 * An opaque handle representing an open HID device.
67 *
68 * \since This struct is available since SDL 3.2.0.
69 */
70typedef struct SDL_hid_device SDL_hid_device;
71
72/**
73 * HID underlying bus types.
74 *
75 * \since This enum is available since SDL 3.2.0.
76 */
77typedef enum SDL_hid_bus_type {
78 /** Unknown bus type */
79 SDL_HID_API_BUS_UNKNOWN = 0x00,
80
81 /** USB bus
82 Specifications:
83 https://usb.org/hid */
84 SDL_HID_API_BUS_USB = 0x01,
85
86 /** Bluetooth or Bluetooth LE bus
87 Specifications:
88 https://www.bluetooth.com/specifications/specs/human-interface-device-profile-1-1-1/
89 https://www.bluetooth.com/specifications/specs/hid-service-1-0/
90 https://www.bluetooth.com/specifications/specs/hid-over-gatt-profile-1-0/ */
91 SDL_HID_API_BUS_BLUETOOTH = 0x02,
92
93 /** I2C bus
94 Specifications:
95 https://docs.microsoft.com/previous-versions/windows/hardware/design/dn642101(v=vs.85) */
96 SDL_HID_API_BUS_I2C = 0x03,
97
98 /** SPI bus
99 Specifications:
100 https://www.microsoft.com/download/details.aspx?id=103325 */
101 SDL_HID_API_BUS_SPI = 0x04
102
103} SDL_hid_bus_type;
104
105/** hidapi info structure */
106
107/**
108 * Information about a connected HID device
109 *
110 * \since This struct is available since SDL 3.2.0.
111 */
112typedef struct SDL_hid_device_info
113{
114 /** Platform-specific device path */
115 char *path;
116 /** Device Vendor ID */
117 unsigned short vendor_id;
118 /** Device Product ID */
119 unsigned short product_id;
120 /** Serial Number */
121 wchar_t *serial_number;
122 /** Device Release Number in binary-coded decimal,
123 also known as Device Version Number */
124 unsigned short release_number;
125 /** Manufacturer String */
126 wchar_t *manufacturer_string;
127 /** Product string */
128 wchar_t *product_string;
129 /** Usage Page for this Device/Interface
130 (Windows/Mac/hidraw only) */
131 unsigned short usage_page;
132 /** Usage for this Device/Interface
133 (Windows/Mac/hidraw only) */
134 unsigned short usage;
135 /** The USB interface which this logical device
136 represents.
137
138 Valid only if the device is a USB HID device.
139 Set to -1 in all other cases.
140 */
141 int interface_number;
142
143 /** Additional information about the USB interface.
144 Valid on libusb and Android implementations. */
145 int interface_class;
146 int interface_subclass;
147 int interface_protocol;
148
149 /** Underlying bus type */
150 SDL_hid_bus_type bus_type;
151
152 /** Pointer to the next device */
153 struct SDL_hid_device_info *next;
154
155} SDL_hid_device_info;
156
157
158/**
159 * Initialize the HIDAPI library.
160 *
161 * This function initializes the HIDAPI library. Calling it is not strictly
162 * necessary, as it will be called automatically by SDL_hid_enumerate() and
163 * any of the SDL_hid_open_*() functions if it is needed. This function should
164 * be called at the beginning of execution however, if there is a chance of
165 * HIDAPI handles being opened by different threads simultaneously.
166 *
167 * Each call to this function should have a matching call to SDL_hid_exit()
168 *
169 * \returns 0 on success or a negative error code on failure; call
170 * SDL_GetError() for more information.
171 *
172 * \since This function is available since SDL 3.2.0.
173 *
174 * \sa SDL_hid_exit
175 */
176extern SDL_DECLSPEC int SDLCALL SDL_hid_init(void);
177
178/**
179 * Finalize the HIDAPI library.
180 *
181 * This function frees all of the static data associated with HIDAPI. It
182 * should be called at the end of execution to avoid memory leaks.
183 *
184 * \returns 0 on success or a negative error code on failure; call
185 * SDL_GetError() for more information.
186 *
187 * \since This function is available since SDL 3.2.0.
188 *
189 * \sa SDL_hid_init
190 */
191extern SDL_DECLSPEC int SDLCALL SDL_hid_exit(void);
192
193/**
194 * Check to see if devices may have been added or removed.
195 *
196 * Enumerating the HID devices is an expensive operation, so you can call this
197 * to see if there have been any system device changes since the last call to
198 * this function. A change in the counter returned doesn't necessarily mean
199 * that anything has changed, but you can call SDL_hid_enumerate() to get an
200 * updated device list.
201 *
202 * Calling this function for the first time may cause a thread or other system
203 * resource to be allocated to track device change notifications.
204 *
205 * \returns a change counter that is incremented with each potential device
206 * change, or 0 if device change detection isn't available.
207 *
208 * \since This function is available since SDL 3.2.0.
209 *
210 * \sa SDL_hid_enumerate
211 */
212extern SDL_DECLSPEC Uint32 SDLCALL SDL_hid_device_change_count(void);
213
214/**
215 * Enumerate the HID Devices.
216 *
217 * This function returns a linked list of all the HID devices attached to the
218 * system which match vendor_id and product_id. If `vendor_id` is set to 0
219 * then any vendor matches. If `product_id` is set to 0 then any product
220 * matches. If `vendor_id` and `product_id` are both set to 0, then all HID
221 * devices will be returned.
222 *
223 * By default SDL will only enumerate controllers, to reduce risk of hanging
224 * or crashing on bad drivers, but SDL_HINT_HIDAPI_ENUMERATE_ONLY_CONTROLLERS
225 * can be set to "0" to enumerate all HID devices.
226 *
227 * \param vendor_id the Vendor ID (VID) of the types of device to open, or 0
228 * to match any vendor.
229 * \param product_id the Product ID (PID) of the types of device to open, or 0
230 * to match any product.
231 * \returns a pointer to a linked list of type SDL_hid_device_info, containing
232 * information about the HID devices attached to the system, or NULL
233 * in the case of failure. Free this linked list by calling
234 * SDL_hid_free_enumeration().
235 *
236 * \since This function is available since SDL 3.2.0.
237 *
238 * \sa SDL_hid_device_change_count
239 */
240extern SDL_DECLSPEC SDL_hid_device_info * SDLCALL SDL_hid_enumerate(unsigned short vendor_id, unsigned short product_id);
241
242/**
243 * Free an enumeration linked list.
244 *
245 * This function frees a linked list created by SDL_hid_enumerate().
246 *
247 * \param devs pointer to a list of struct_device returned from
248 * SDL_hid_enumerate().
249 *
250 * \since This function is available since SDL 3.2.0.
251 */
252extern SDL_DECLSPEC void SDLCALL SDL_hid_free_enumeration(SDL_hid_device_info *devs);
253
254/**
255 * Open a HID device using a Vendor ID (VID), Product ID (PID) and optionally
256 * a serial number.
257 *
258 * If `serial_number` is NULL, the first device with the specified VID and PID
259 * is opened.
260 *
261 * \param vendor_id the Vendor ID (VID) of the device to open.
262 * \param product_id the Product ID (PID) of the device to open.
263 * \param serial_number the Serial Number of the device to open (Optionally
264 * NULL).
265 * \returns a pointer to a SDL_hid_device object on success or NULL on
266 * failure; call SDL_GetError() for more information.
267 *
268 * \since This function is available since SDL 3.2.0.
269 */
270extern SDL_DECLSPEC SDL_hid_device * SDLCALL SDL_hid_open(unsigned short vendor_id, unsigned short product_id, const wchar_t *serial_number);
271
272/**
273 * Open a HID device by its path name.
274 *
275 * The path name be determined by calling SDL_hid_enumerate(), or a
276 * platform-specific path name can be used (eg: /dev/hidraw0 on Linux).
277 *
278 * \param path the path name of the device to open.
279 * \returns a pointer to a SDL_hid_device object on success or NULL on
280 * failure; call SDL_GetError() for more information.
281 *
282 * \since This function is available since SDL 3.2.0.
283 */
284extern SDL_DECLSPEC SDL_hid_device * SDLCALL SDL_hid_open_path(const char *path);
285
286/**
287 * Write an Output report to a HID device.
288 *
289 * The first byte of `data` must contain the Report ID. For devices which only
290 * support a single report, this must be set to 0x0. The remaining bytes
291 * contain the report data. Since the Report ID is mandatory, calls to
292 * SDL_hid_write() will always contain one more byte than the report contains.
293 * For example, if a hid report is 16 bytes long, 17 bytes must be passed to
294 * SDL_hid_write(), the Report ID (or 0x0, for devices with a single report),
295 * followed by the report data (16 bytes). In this example, the length passed
296 * in would be 17.
297 *
298 * SDL_hid_write() will send the data on the first OUT endpoint, if one
299 * exists. If it does not, it will send the data through the Control Endpoint
300 * (Endpoint 0).
301 *
302 * \param dev a device handle returned from SDL_hid_open().
303 * \param data the data to send, including the report number as the first
304 * byte.
305 * \param length the length in bytes of the data to send.
306 * \returns the actual number of bytes written and -1 on on failure; call
307 * SDL_GetError() for more information.
308 *
309 * \since This function is available since SDL 3.2.0.
310 */
311extern SDL_DECLSPEC int SDLCALL SDL_hid_write(SDL_hid_device *dev, const unsigned char *data, size_t length);
312
313/**
314 * Read an Input report from a HID device with timeout.
315 *
316 * Input reports are returned to the host through the INTERRUPT IN endpoint.
317 * The first byte will contain the Report number if the device uses numbered
318 * reports.
319 *
320 * \param dev a device handle returned from SDL_hid_open().
321 * \param data a buffer to put the read data into.
322 * \param length the number of bytes to read. For devices with multiple
323 * reports, make sure to read an extra byte for the report
324 * number.
325 * \param milliseconds timeout in milliseconds or -1 for blocking wait.
326 * \returns the actual number of bytes read and -1 on on failure; call
327 * SDL_GetError() for more information. If no packet was available to
328 * be read within the timeout period, this function returns 0.
329 *
330 * \since This function is available since SDL 3.2.0.
331 */
332extern SDL_DECLSPEC int SDLCALL SDL_hid_read_timeout(SDL_hid_device *dev, unsigned char *data, size_t length, int milliseconds);
333
334/**
335 * Read an Input report from a HID device.
336 *
337 * Input reports are returned to the host through the INTERRUPT IN endpoint.
338 * The first byte will contain the Report number if the device uses numbered
339 * reports.
340 *
341 * \param dev a device handle returned from SDL_hid_open().
342 * \param data a buffer to put the read data into.
343 * \param length the number of bytes to read. For devices with multiple
344 * reports, make sure to read an extra byte for the report
345 * number.
346 * \returns the actual number of bytes read and -1 on failure; call
347 * SDL_GetError() for more information. If no packet was available to
348 * be read and the handle is in non-blocking mode, this function
349 * returns 0.
350 *
351 * \since This function is available since SDL 3.2.0.
352 */
353extern SDL_DECLSPEC int SDLCALL SDL_hid_read(SDL_hid_device *dev, unsigned char *data, size_t length);
354
355/**
356 * Set the device handle to be non-blocking.
357 *
358 * In non-blocking mode calls to SDL_hid_read() will return immediately with a
359 * value of 0 if there is no data to be read. In blocking mode, SDL_hid_read()
360 * will wait (block) until there is data to read before returning.
361 *
362 * Nonblocking can be turned on and off at any time.
363 *
364 * \param dev a device handle returned from SDL_hid_open().
365 * \param nonblock enable or not the nonblocking reads - 1 to enable
366 * nonblocking - 0 to disable nonblocking.
367 * \returns 0 on success or a negative error code on failure; call
368 * SDL_GetError() for more information.
369 *
370 * \since This function is available since SDL 3.2.0.
371 */
372extern SDL_DECLSPEC int SDLCALL SDL_hid_set_nonblocking(SDL_hid_device *dev, int nonblock);
373
374/**
375 * Send a Feature report to the device.
376 *
377 * Feature reports are sent over the Control endpoint as a Set_Report
378 * transfer. The first byte of `data` must contain the Report ID. For devices
379 * which only support a single report, this must be set to 0x0. The remaining
380 * bytes contain the report data. Since the Report ID is mandatory, calls to
381 * SDL_hid_send_feature_report() will always contain one more byte than the
382 * report contains. For example, if a hid report is 16 bytes long, 17 bytes
383 * must be passed to SDL_hid_send_feature_report(): the Report ID (or 0x0, for
384 * devices which do not use numbered reports), followed by the report data (16
385 * bytes). In this example, the length passed in would be 17.
386 *
387 * \param dev a device handle returned from SDL_hid_open().
388 * \param data the data to send, including the report number as the first
389 * byte.
390 * \param length the length in bytes of the data to send, including the report
391 * number.
392 * \returns the actual number of bytes written and -1 on failure; call
393 * SDL_GetError() for more information.
394 *
395 * \since This function is available since SDL 3.2.0.
396 */
397extern SDL_DECLSPEC int SDLCALL SDL_hid_send_feature_report(SDL_hid_device *dev, const unsigned char *data, size_t length);
398
399/**
400 * Get a feature report from a HID device.
401 *
402 * Set the first byte of `data` to the Report ID of the report to be read.
403 * Make sure to allow space for this extra byte in `data`. Upon return, the
404 * first byte will still contain the Report ID, and the report data will start
405 * in data[1].
406 *
407 * \param dev a device handle returned from SDL_hid_open().
408 * \param data a buffer to put the read data into, including the Report ID.
409 * Set the first byte of `data` to the Report ID of the report to
410 * be read, or set it to zero if your device does not use numbered
411 * reports.
412 * \param length the number of bytes to read, including an extra byte for the
413 * report ID. The buffer can be longer than the actual report.
414 * \returns the number of bytes read plus one for the report ID (which is
415 * still in the first byte), or -1 on on failure; call SDL_GetError()
416 * for more information.
417 *
418 * \since This function is available since SDL 3.2.0.
419 */
420extern SDL_DECLSPEC int SDLCALL SDL_hid_get_feature_report(SDL_hid_device *dev, unsigned char *data, size_t length);
421
422/**
423 * Get an input report from a HID device.
424 *
425 * Set the first byte of `data` to the Report ID of the report to be read.
426 * Make sure to allow space for this extra byte in `data`. Upon return, the
427 * first byte will still contain the Report ID, and the report data will start
428 * in data[1].
429 *
430 * \param dev a device handle returned from SDL_hid_open().
431 * \param data a buffer to put the read data into, including the Report ID.
432 * Set the first byte of `data` to the Report ID of the report to
433 * be read, or set it to zero if your device does not use numbered
434 * reports.
435 * \param length the number of bytes to read, including an extra byte for the
436 * report ID. The buffer can be longer than the actual report.
437 * \returns the number of bytes read plus one for the report ID (which is
438 * still in the first byte), or -1 on on failure; call SDL_GetError()
439 * for more information.
440 *
441 * \since This function is available since SDL 3.2.0.
442 */
443extern SDL_DECLSPEC int SDLCALL SDL_hid_get_input_report(SDL_hid_device *dev, unsigned char *data, size_t length);
444
445/**
446 * Close a HID device.
447 *
448 * \param dev a device handle returned from SDL_hid_open().
449 * \returns 0 on success or a negative error code on failure; call
450 * SDL_GetError() for more information.
451 *
452 * \since This function is available since SDL 3.2.0.
453 */
454extern SDL_DECLSPEC int SDLCALL SDL_hid_close(SDL_hid_device *dev);
455
456/**
457 * Get The Manufacturer String from a HID device.
458 *
459 * \param dev a device handle returned from SDL_hid_open().
460 * \param string a wide string buffer to put the data into.
461 * \param maxlen the length of the buffer in multiples of wchar_t.
462 * \returns 0 on success or a negative error code on failure; call
463 * SDL_GetError() for more information.
464 *
465 * \since This function is available since SDL 3.2.0.
466 */
467extern SDL_DECLSPEC int SDLCALL SDL_hid_get_manufacturer_string(SDL_hid_device *dev, wchar_t *string, size_t maxlen);
468
469/**
470 * Get The Product String from a HID device.
471 *
472 * \param dev a device handle returned from SDL_hid_open().
473 * \param string a wide string buffer to put the data into.
474 * \param maxlen the length of the buffer in multiples of wchar_t.
475 * \returns 0 on success or a negative error code on failure; call
476 * SDL_GetError() for more information.
477 *
478 * \since This function is available since SDL 3.2.0.
479 */
480extern SDL_DECLSPEC int SDLCALL SDL_hid_get_product_string(SDL_hid_device *dev, wchar_t *string, size_t maxlen);
481
482/**
483 * Get The Serial Number String from a HID device.
484 *
485 * \param dev a device handle returned from SDL_hid_open().
486 * \param string a wide string buffer to put the data into.
487 * \param maxlen the length of the buffer in multiples of wchar_t.
488 * \returns 0 on success or a negative error code on failure; call
489 * SDL_GetError() for more information.
490 *
491 * \since This function is available since SDL 3.2.0.
492 */
493extern SDL_DECLSPEC int SDLCALL SDL_hid_get_serial_number_string(SDL_hid_device *dev, wchar_t *string, size_t maxlen);
494
495/**
496 * Get a string from a HID device, based on its string index.
497 *
498 * \param dev a device handle returned from SDL_hid_open().
499 * \param string_index the index of the string to get.
500 * \param string a wide string buffer to put the data into.
501 * \param maxlen the length of the buffer in multiples of wchar_t.
502 * \returns 0 on success or a negative error code on failure; call
503 * SDL_GetError() for more information.
504 *
505 * \since This function is available since SDL 3.2.0.
506 */
507extern SDL_DECLSPEC int SDLCALL SDL_hid_get_indexed_string(SDL_hid_device *dev, int string_index, wchar_t *string, size_t maxlen);
508
509/**
510 * Get the device info from a HID device.
511 *
512 * \param dev a device handle returned from SDL_hid_open().
513 * \returns a pointer to the SDL_hid_device_info for this hid_device or NULL
514 * on failure; call SDL_GetError() for more information. This struct
515 * is valid until the device is closed with SDL_hid_close().
516 *
517 * \since This function is available since SDL 3.2.0.
518 */
519extern SDL_DECLSPEC SDL_hid_device_info * SDLCALL SDL_hid_get_device_info(SDL_hid_device *dev);
520
521/**
522 * Get a report descriptor from a HID device.
523 *
524 * User has to provide a preallocated buffer where descriptor will be copied
525 * to. The recommended size for a preallocated buffer is 4096 bytes.
526 *
527 * \param dev a device handle returned from SDL_hid_open().
528 * \param buf the buffer to copy descriptor into.
529 * \param buf_size the size of the buffer in bytes.
530 * \returns the number of bytes actually copied or -1 on failure; call
531 * SDL_GetError() for more information.
532 *
533 * \since This function is available since SDL 3.2.0.
534 */
535extern SDL_DECLSPEC int SDLCALL SDL_hid_get_report_descriptor(SDL_hid_device *dev, unsigned char *buf, size_t buf_size);
536
537/**
538 * Start or stop a BLE scan on iOS and tvOS to pair Steam Controllers.
539 *
540 * \param active true to start the scan, false to stop the scan.
541 *
542 * \since This function is available since SDL 3.2.0.
543 */
544extern SDL_DECLSPEC void SDLCALL SDL_hid_ble_scan(bool active);
545
546/* Ends C function definitions when using C++ */
547#ifdef __cplusplus
548}
549#endif
550#include <SDL3/SDL_close_code.h>
551
552#endif /* SDL_hidapi_h_ */
553