Prototype adapter XInput feasibility

2026-09-02 07:53:18 -06:00 · 2026-09-02 07:53:18 -06:00 · 17b3d7399c
commit 17b3d7399c
parent fd23842327
13 changed files with 953 additions and 13 deletions
--- a/adapter_host_probe.cpp
+++ b/adapter_host_probe.cpp
@ -0,0 +1,87 @@
+#include "adapter_host_probe.h"
+
+#include <stddef.h>
+#ifdef SWITCH_PICO_LOG
+#include <stdio.h>
+#define PROBE_LOG(...) printf(__VA_ARGS__)
+#else
+#define PROBE_LOG(...) ((void)0)
+#endif
+
+#include "adapter_host_probe_state.h"
+#include "hardware/structs/watchdog.h"
+#include "hardware/watchdog.h"
+#include "pico/time.h"
+#include "xinput_feasibility_descriptors.h"
+
+namespace {
+
+constexpr uint32_t kXInputBootMagic = 0x58494e50; // "XINP"
+constexpr uint8_t kModeScratchRegister = 0;
+
+AdapterUsbMode g_mode = AdapterUsbMode::kSwitchProbe;
+AdapterHostProbeState g_probe;
+
+uint32_t now_ms() {
+    return static_cast<uint32_t>(to_ms_since_boot(get_absolute_time()));
+}
+
+} // namespace
+
+void adapter_host_probe_init() {
+    if (watchdog_hw->scratch[kModeScratchRegister] == kXInputBootMagic) {
+        watchdog_hw->scratch[kModeScratchRegister] = 0;
+        g_mode = AdapterUsbMode::kXInput;
+    } else {
+        g_mode = AdapterUsbMode::kSwitchProbe;
+    }
+    g_probe = {};
+    PROBE_LOG("[HOST PROBE] boot mode=%s\n",
+              g_mode == AdapterUsbMode::kXInput ? "XInput" : "Switch probe");
+}
+
+AdapterUsbMode adapter_host_probe_mode() { return g_mode; }
+
+void adapter_host_probe_note_string_descriptor(uint8_t index) {
+    if (g_mode == AdapterUsbMode::kSwitchProbe && index == 0xee) {
+        g_probe.note_ms_os_string();
+        PROBE_LOG("[HOST PROBE] Microsoft OS string requested\n");
+    }
+}
+
+bool adapter_host_probe_vendor_control(uint8_t rhport, uint8_t stage,
+                                       tusb_control_request_t const *request) {
+    if (stage != CONTROL_STAGE_SETUP || request == nullptr ||
+        request->bmRequestType_bit.direction != TUSB_DIR_IN ||
+        request->bmRequestType_bit.type != TUSB_REQ_TYPE_VENDOR ||
+        request->bmRequestType_bit.recipient != TUSB_REQ_RCPT_DEVICE ||
+        request->bRequest != XInputFeasibility::kMsVendorRequest ||
+        request->wIndex != XInputFeasibility::kMsCompatIdIndex) {
+        return false;
+    }
+
+    if (g_mode == AdapterUsbMode::kSwitchProbe) {
+        g_probe.note_ms_compat_id_request(now_ms());
+        PROBE_LOG("[HOST PROBE] Microsoft compatible-ID request confirmed\n");
+        return tud_control_xfer(
+            rhport, request,
+            const_cast<uint8_t *>(
+                XInputFeasibility::kProbeMsCompatIdDescriptor),
+            sizeof(XInputFeasibility::kProbeMsCompatIdDescriptor));
+    }
+
+    return tud_control_xfer(
+        rhport, request,
+        const_cast<uint8_t *>(XInputFeasibility::kMsCompatIdDescriptor),
+        sizeof(XInputFeasibility::kMsCompatIdDescriptor));
+}
+
+void adapter_host_probe_task() {
+    if (g_mode != AdapterUsbMode::kSwitchProbe ||
+        !g_probe.should_reboot(now_ms())) {
+        return;
+    }
+    watchdog_hw->scratch[kModeScratchRegister] = kXInputBootMagic;
+    PROBE_LOG("[HOST PROBE] rebooting once into XInput\n");
+    watchdog_reboot(0, 0, 10);
+}