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From: Benjamin Tissoires <bentiss@kernel.org>
Date: Wed, 10 Apr 2024 19:19:29 +0200
Subject: [PATCH 09/18] HID: bpf: add in-tree HID-BPF fix for the Raptor
 Mach 2
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Message-Id: <20240410-bpf_sources-v1-9-a8bf16033ef8@kernel.org>
References: <20240410-bpf_sources-v1-0-a8bf16033ef8@kernel.org>
In-Reply-To: <20240410-bpf_sources-v1-0-a8bf16033ef8@kernel.org>
To: Jiri Kosina <jikos@kernel.org>, Benjamin Tissoires <bentiss@kernel.org>, 
 Shuah Khan <shuah@kernel.org>, Peter Hutterer <peter.hutterer@who-t.net>
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, 
 linux-kselftest@vger.kernel.org

This device is already fixed by "HID: do not assume HAT Switch
logical max < 8", but for people without the fix already, having the
HID-BPF locally can fix the device while they wait for their
distribution to update.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
 drivers/hid/bpf/progs/FR-TEC__Raptor-Mach-2.bpf.c | 185 ++++++++++++++++++++++
 1 file changed, 185 insertions(+)

diff --git a/drivers/hid/bpf/progs/FR-TEC__Raptor-Mach-2.bpf.c b/drivers/hid/bpf/progs/FR-TEC__Raptor-Mach-2.bpf.c
new file mode 100644
index 000000000000..dc26a7677d36
--- /dev/null
+++ b/drivers/hid/bpf/progs/FR-TEC__Raptor-Mach-2.bpf.c
@@ -0,0 +1,185 @@
+// 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("fmod_ret/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("fmod_ret/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;
+}
+
+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";

-- 
2.44.0