[Voyageurs] Send GetDescriptor command to the device.

sys/voyageurs/xhci/control_command.h

@@ -0,0 +1,69 @@
+#pragma once
+
+#include <glacier/memory/shared_ptr.h>
+#include <mammoth/sync/semaphore.h>
+#include <mammoth/util/memory_region.h>
+
+#include "xhci/descriptors.h"
+#include "xhci/xhci.h"
+
+template <typename Output>
+class ReadControlCommand {
+ public:
+  ReadControlCommand() {
+    output_mem_ =
+        mmth::OwnedMemoryRegion::ContiguousPhysical(0x1000, &output_phys_);
+  }
+
+  XhciTrb SetupTrb() {
+    uint64_t request_type = RequestConstants<Output>::RequestType();
+    uint64_t request = RequestConstants<Output>::Request() << 8;
+    uint64_t value = RequestConstants<Output>::Value() << 16;
+    // TODO: May need to be non-0 for string descriptors.
+    uint64_t index = (uint64_t)0 << 32;
+    uint64_t length = sizeof(Output) << 48;
+    return {
+        .parameter = request_type | request | value | index | length,
+        .status = 8,
+        .type_and_cycle = 1 | (1 << 5) | (1 << 6) | (2 << 10),
+        // IN Data Stage
+        .control = 3,
+    };
+  }
+
+  XhciTrb DataTrb() {
+    return {
+        .parameter = output_phys_,
+        .status = sizeof(Output),
+        .type_and_cycle = 1 | (1 << 5) | (3 << 10),
+        .control = 1,
+    };
+  }
+
+  XhciTrb StatusTrb() {
+    return {
+        .parameter = 0,
+        .status = 0,
+        .type_and_cycle = 1 | (1 << 5) | (4 << 10),
+        .control = 0,
+    };
+  }
+
+  Output* AwaitResult() {
+    if (!is_complete_) {
+      semaphore_->Wait();
+    }
+    is_complete_ = true;
+    return reinterpret_cast<Output*>(output_mem_.vaddr());
+  }
+
+  glcr::SharedPtr<mmth::Semaphore> CompletionSemaphore() { return semaphore_; }
+
+ private:
+  uint64_t output_phys_;
+  mmth::OwnedMemoryRegion output_mem_;
+
+  bool is_complete_ = false;
+  glcr::SharedPtr<mmth::Semaphore> semaphore_ =
+      glcr::MakeShared<mmth::Semaphore>();
+};