// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2024 Benjamin Tissoires
*/
#include "vmlinux.h"
#include "hid_bpf.h"
#include "hid_bpf_helpers.h"
#include <bpf/bpf_tracing.h>
#define VID_BETOP_2185PC 0x11C0
#define PID_RAPTOR_MACH_2 0x5606
HID_BPF_CONFIG(
HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_BETOP_2185PC, PID_RAPTOR_MACH_2),
);
/*
* For reference, this is the fixed report descriptor
*
* static const __u8 fixed_rdesc[] = {
* 0x05, 0x01, // Usage Page (Generic Desktop) 0
* 0x09, 0x04, // Usage (Joystick) 2
* 0xa1, 0x01, // Collection (Application) 4
* 0x05, 0x01, // Usage Page (Generic Desktop) 6
* 0x85, 0x01, // Report ID (1) 8
* 0x05, 0x01, // Usage Page (Generic Desktop) 10
* 0x09, 0x30, // Usage (X) 12
* 0x75, 0x10, // Report Size (16) 14
* 0x95, 0x01, // Report Count (1) 16
* 0x15, 0x00, // Logical Minimum (0) 18
* 0x26, 0xff, 0x07, // Logical Maximum (2047) 20
* 0x46, 0xff, 0x07, // Physical Maximum (2047) 23
* 0x81, 0x02, // Input (Data,Var,Abs) 26
* 0x05, 0x01, // Usage Page (Generic Desktop) 28
* 0x09, 0x31, // Usage (Y) 30
* 0x75, 0x10, // Report Size (16) 32
* 0x95, 0x01, // Report Count (1) 34
* 0x15, 0x00, // Logical Minimum (0) 36
* 0x26, 0xff, 0x07, // Logical Maximum (2047) 38
* 0x46, 0xff, 0x07, // Physical Maximum (2047) 41
* 0x81, 0x02, // Input (Data,Var,Abs) 44
* 0x05, 0x01, // Usage Page (Generic Desktop) 46
* 0x09, 0x33, // Usage (Rx) 48
* 0x75, 0x10, // Report Size (16) 50
* 0x95, 0x01, // Report Count (1) 52
* 0x15, 0x00, // Logical Minimum (0) 54
* 0x26, 0xff, 0x03, // Logical Maximum (1023) 56
* 0x46, 0xff, 0x03, // Physical Maximum (1023) 59
* 0x81, 0x02, // Input (Data,Var,Abs) 62
* 0x05, 0x00, // Usage Page (Undefined) 64
* 0x09, 0x00, // Usage (Undefined) 66
* 0x75, 0x10, // Report Size (16) 68
* 0x95, 0x01, // Report Count (1) 70
* 0x15, 0x00, // Logical Minimum (0) 72
* 0x26, 0xff, 0x03, // Logical Maximum (1023) 74
* 0x46, 0xff, 0x03, // Physical Maximum (1023) 77
* 0x81, 0x02, // Input (Data,Var,Abs) 80
* 0x05, 0x01, // Usage Page (Generic Desktop) 82
* 0x09, 0x32, // Usage (Z) 84
* 0x75, 0x10, // Report Size (16) 86
* 0x95, 0x01, // Report Count (1) 88
* 0x15, 0x00, // Logical Minimum (0) 90
* 0x26, 0xff, 0x03, // Logical Maximum (1023) 92
* 0x46, 0xff, 0x03, // Physical Maximum (1023) 95
* 0x81, 0x02, // Input (Data,Var,Abs) 98
* 0x05, 0x01, // Usage Page (Generic Desktop) 100
* 0x09, 0x35, // Usage (Rz) 102
* 0x75, 0x10, // Report Size (16) 104
* 0x95, 0x01, // Report Count (1) 106
* 0x15, 0x00, // Logical Minimum (0) 108
* 0x26, 0xff, 0x03, // Logical Maximum (1023) 110
* 0x46, 0xff, 0x03, // Physical Maximum (1023) 113
* 0x81, 0x02, // Input (Data,Var,Abs) 116
* 0x05, 0x01, // Usage Page (Generic Desktop) 118
* 0x09, 0x34, // Usage (Ry) 120
* 0x75, 0x10, // Report Size (16) 122
* 0x95, 0x01, // Report Count (1) 124
* 0x15, 0x00, // Logical Minimum (0) 126
* 0x26, 0xff, 0x07, // Logical Maximum (2047) 128
* 0x46, 0xff, 0x07, // Physical Maximum (2047) 131
* 0x81, 0x02, // Input (Data,Var,Abs) 134
* 0x05, 0x01, // Usage Page (Generic Desktop) 136
* 0x09, 0x36, // Usage (Slider) 138
* 0x75, 0x10, // Report Size (16) 140
* 0x95, 0x01, // Report Count (1) 142
* 0x15, 0x00, // Logical Minimum (0) 144
* 0x26, 0xff, 0x03, // Logical Maximum (1023) 146
* 0x46, 0xff, 0x03, // Physical Maximum (1023) 149
* 0x81, 0x02, // Input (Data,Var,Abs) 152
* 0x05, 0x09, // Usage Page (Button) 154
* 0x19, 0x01, // Usage Minimum (1) 156
* 0x2a, 0x1d, 0x00, // Usage Maximum (29) 158
* 0x15, 0x00, // Logical Minimum (0) 161
* 0x25, 0x01, // Logical Maximum (1) 163
* 0x75, 0x01, // Report Size (1) 165
* 0x96, 0x80, 0x00, // Report Count (128) 167
* 0x81, 0x02, // Input (Data,Var,Abs) 170
* 0x05, 0x01, // Usage Page (Generic Desktop) 172
* 0x09, 0x39, // Usage (Hat switch) 174
* 0x26, 0x07, 0x00, // Logical Maximum (7) 176 // changed (was 239)
* 0x46, 0x68, 0x01, // Physical Maximum (360) 179
* 0x65, 0x14, // Unit (EnglishRotation: deg) 182
* 0x75, 0x10, // Report Size (16) 184
* 0x95, 0x01, // Report Count (1) 186
* 0x81, 0x42, // Input (Data,Var,Abs,Null) 188
* 0x05, 0x01, // Usage Page (Generic Desktop) 190
* 0x09, 0x00, // Usage (Undefined) 192
* 0x75, 0x08, // Report Size (8) 194
* 0x95, 0x1d, // Report Count (29) 196
* 0x81, 0x01, // Input (Cnst,Arr,Abs) 198
* 0x15, 0x00, // Logical Minimum (0) 200
* 0x26, 0xef, 0x00, // Logical Maximum (239) 202
* 0x85, 0x58, // Report ID (88) 205
* 0x26, 0xff, 0x00, // Logical Maximum (255) 207
* 0x46, 0xff, 0x00, // Physical Maximum (255) 210
* 0x75, 0x08, // Report Size (8) 213
* 0x95, 0x3f, // Report Count (63) 215
* 0x09, 0x00, // Usage (Undefined) 217
* 0x91, 0x02, // Output (Data,Var,Abs) 219
* 0x85, 0x59, // Report ID (89) 221
* 0x75, 0x08, // Report Size (8) 223
* 0x95, 0x80, // Report Count (128) 225
* 0x09, 0x00, // Usage (Undefined) 227
* 0xb1, 0x02, // Feature (Data,Var,Abs) 229
* 0xc0, // End Collection 231
* };
*/
/*
* We need to amend the report descriptor for the following:
* - the joystick sends its hat_switch data between 0 and 239 but
* the kernel expects the logical max to stick into a signed 8 bits
* integer. We thus divide it by 30 to match what other joysticks are
* doing
*/
SEC(HID_BPF_RDESC_FIXUP)
int BPF_PROG(hid_fix_rdesc_raptor_mach_2, struct hid_bpf_ctx *hctx)
{
__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, HID_MAX_DESCRIPTOR_SIZE /* size */);
if (!data)
return 0; /* EPERM check */
data[177] = 0x07;
return 0;
}
/*
* The hat_switch value at offsets 33 and 34 (16 bits) needs
* to be reduced to a single 8 bit signed integer. So we
* divide it by 30.
* Byte 34 is always null, so it is ignored.
*/
SEC(HID_BPF_DEVICE_EVENT)
int BPF_PROG(raptor_mach_2_fix_hat_switch, struct hid_bpf_ctx *hctx)
{
__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 64 /* size */);
if (!data)
return 0; /* EPERM check */
if (data[0] != 0x01) /* not the joystick report ID */
return 0;
data[33] /= 30;
return 0;
}
HID_BPF_OPS(raptor_mach_2) = {
.hid_rdesc_fixup = (void *)hid_fix_rdesc_raptor_mach_2,
.hid_device_event = (void *)raptor_mach_2_fix_hat_switch,
};
SEC("syscall")
int probe(struct hid_bpf_probe_args *ctx)
{
ctx->retval = ctx->rdesc_size != 232;
if (ctx->retval)
ctx->retval = -EINVAL;
/* ensure the kernel isn't fixed already */
if (ctx->rdesc[177] != 0xef) /* Logical Max of 239 */
ctx->retval = -EINVAL;
return 0;
}
char _license[] SEC("license") = "GPL";
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