1 // SPDX-License-Identifier: GPL-2.0-only
18 /* Filled in by udev-hid-bpf */
27  * tablet mode. In firmware mode (out of the box) the tablet sends button events
33  * To switch the tablet use e.g.  https://github.com/whot/huion-switcher
36  * This BPF currently works for both modes only. The huion-switcher tool sets the
37  * HUION_FIRMWARE_ID udev property - if that is set then we disable the firmware
49  * # 0xa1, 0x01,                    // Collection (Application)                  5
60  * Second hidraw node is the Pad. This one sends the button events until the tablet is
102  * # 0x85, 0x05,                    //   Report ID (5)                           75
104  * # 0x05, 0x09,                    //     Usage Page (Button)                   79
106  * # 0x29, 0x05,                    //     UsageMaximum (5)                      83
109  * # 0x95, 0x05,                    //     Report Count (5)                      89
118  * # 0x16, 0x00, 0x80,              //     Logical Minimum (-32768)              107
127  * # 0x15, 0x81,                    //     Logical Minimum (-127)                127
134  * Third hidraw node is a multi-axis controller which sends the dial events
135  * and the button inside the dial. If the tablet is switched to raw mode it is mute.
140  * # 0x09, 0x0e,                    // Usage (System Multi-Axis Controller)      2
151  * # 0x05, 0x09,                    //       Usage Page (Button)                 24
152  * # 0x09, 0x01,                    //       Usage (Button 1)                    26
162  * # 0x16, 0x00, 0x80,              //         Logical Minimum (-32768)          46
233 			// Byte 1 is a button so we look like a tablet
240 			// Bytes 2/3 - x/y just exist so we get to be a tablet pad
249 			// Bytes 4-7 are the button state for 19 buttons + pad out to u32
250 			// We send the first 10 buttons as buttons 1-10 which is BTN_0 -> BTN_9
259 			// We send the other 9 buttons as buttons 0x31 and above -> BTN_A - BTN_TL2
271 			LogicalMinimum_i8(-1)
293 			// Byte 1 is a button so we look like a tablet
300 			// Bytes 2/3 - x/y just exist so we get to be a tablet pad
309 			// Bytes 4-7 are the button state for 19 buttons + pad out to u32
310 			// We send the first 10 buttons as buttons 1-10 which is BTN_0 -> BTN_9
319 			// We send the other 9 buttons as buttons 0x31 and above -> BTN_A - BTN_TL2
331 			LogicalMinimum_i8(-1)
348 	__s32 rdesc_size = hctx->size;  in SEC()
360 				      sizeof(EXPECTED_FIRMWARE_ID) - 1) == 0;  in SEC()
378 	 * the udev property (e.g. huion-switcher run manually)  in SEC()
413 			if (data[5] == 2)  in SEC()
416 				wheel = data[5];  in SEC()
419 			last_button_state = data[4] | (data[5] << 8) | (data[6] << 16);  in SEC()
424 		pad_report->report_id = VENDOR_REPORT_ID;  in SEC()
425 		pad_report->btn_stylus = 0;  in SEC()
426 		pad_report->x = 0;  in SEC()
427 		pad_report->y = 0;  in SEC()
428 		pad_report->buttons = last_button_state;  in SEC()
429 		pad_report->wheel = wheel;  in SEC()
436 			0x0e, /* Button 1:  K */  in SEC()
437 			0x0a, /* Button 2:  G */  in SEC()
438 			0x0f, /* Button 3:  L */  in SEC()
439 			0x4c, /* Button 4:  Delete */  in SEC()
440 			0x0c, /* Button 5:  I */  in SEC()
441 			0x07, /* Button 6:  D */  in SEC()
442 			0x05, /* Button 7:  B */  in SEC()
443 			0x08, /* Button 8:  E */  in SEC()
444 			0x16, /* Button 9:  S */  in SEC()
445 			0x1d, /* Button 10: Z */  in SEC()
446 			0x06, /* Button 11: C */  in SEC()
447 			0x19, /* Button 12: V */  in SEC()
448 			0xff, /* Button 13: LeftControl */  in SEC()
449 			0xff, /* Button 14: LeftAlt */  in SEC()
450 			0xff, /* Button 15: LeftShift */  in SEC()
451 			0x28, /* Button 16: Return Enter */  in SEC()
452 			0x2c, /* Button 17: Spacebar */  in SEC()
453 			0x11, /* Button 18: N */  in SEC()
493 		pad_report->report_id = VENDOR_REPORT_ID;  in SEC()
494 		pad_report->btn_stylus = 0;  in SEC()
495 		pad_report->x = 0;  in SEC()
496 		pad_report->y = 0;  in SEC()
497 		pad_report->buttons = buttons;  in SEC()
499 		// values are unreliable (as is the button inside the wheel).  in SEC()
502 		pad_report->wheel = 0;  in SEC()
518 	switch (ctx->rdesc_size) {  in probe()
522 		ctx->retval = 0;  in probe()
525 		ctx->retval = -EINVAL;  in probe()