src/ui/input/drivers/usb-hid/function/one-endpoint-hid-function.cc

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "one-endpoint-hid-function.h"

#include <assert.h>
#include <fidl/fuchsia.driver.framework/cpp/fidl.h>
#include <lib/driver/compat/cpp/banjo_client.h>
#include <lib/driver/component/cpp/driver_export.h>
#include <lib/driver/component/cpp/node_add_args.h>
#include <lib/driver/logging/cpp/logger.h>
#include <lib/zx/result.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <zircon/process.h>
#include <zircon/syscalls.h>

#include <memory>
#include <utility>
#include <vector>

#include <fbl/algorithm.h>
#include <usb/peripheral.h>
#include <usb/usb-request.h>

constexpr int BULK_MAX_PACKET = 512;

namespace one_endpoint_hid_function {

namespace ffdf = fuchsia_driver_framework;
namespace fhidbus = fuchsia_hardware_hidbus;

static const uint8_t boot_mouse_r_desc[50] = {
    0x05, 0x01,  // Usage Page (Generic Desktop Ctrls)
    0x09, 0x02,  // Usage (Mouse)
    0xA1, 0x01,  // Collection (Application)
    0x09, 0x01,  //   Usage (Pointer)
    0xA1, 0x00,  //   Collection (Physical)
    0x05, 0x09,  //     Usage Page (Button)
    0x19, 0x01,  //     Usage Minimum (0x01)
    0x29, 0x03,  //     Usage Maximum (0x03)
    0x15, 0x00,  //     Logical Minimum (0)
    0x25, 0x01,  //     Logical Maximum (1)
    0x95, 0x03,  //     Report Count (3)
    0x75, 0x01,  //     Report Size (1)
    0x81, 0x02,  //     Input (Data,Var,Abs,No Wrap,Linear,No Null Position)
    0x95, 0x01,  //     Report Count (1)
    0x75, 0x05,  //     Report Size (5)
    0x81, 0x03,  //     Input (Const,Var,Abs,No Wrap,Linear,No Null Position)
    0x05, 0x01,  //     Usage Page (Generic Desktop Ctrls)
    0x09, 0x30,  //     Usage (X)
    0x09, 0x31,  //     Usage (Y)
    0x15, 0x81,  //     Logical Minimum (-127)
    0x25, 0x7F,  //     Logical Maximum (127)
    0x75, 0x08,  //     Report Size (8)
    0x95, 0x02,  //     Report Count (2)
    0x81, 0x06,  //     Input (Data,Var,Rel,No Wrap,Linear,No Null Position)
    0xC0,        //   End Collection
    0xC0,        // End Collection
};

size_t FakeUsbHidFunction::UsbFunctionInterfaceGetDescriptorsSize(void* ctx) {
  FakeUsbHidFunction* func = static_cast<FakeUsbHidFunction*>(ctx);
  return func->descriptor_size_;
}

void FakeUsbHidFunction::UsbFunctionInterfaceGetDescriptors(void* ctx,
                                                            uint8_t* out_descriptors_buffer,
                                                            size_t descriptors_size,
                                                            size_t* out_descriptors_actual) {
  FakeUsbHidFunction* func = static_cast<FakeUsbHidFunction*>(ctx);
  memcpy(out_descriptors_buffer, func->descriptor_.get(),
         std::min(descriptors_size, func->descriptor_size_));
  *out_descriptors_actual = func->descriptor_size_;
}

zx_status_t FakeUsbHidFunction::UsbFunctionInterfaceControl(
    void* ctx, const usb_setup_t* setup, const uint8_t* write_buffer, size_t write_size,
    uint8_t* out_read_buffer, size_t read_size, size_t* out_read_actual) {
  FakeUsbHidFunction* func = static_cast<FakeUsbHidFunction*>(ctx);

  if (setup->bm_request_type == (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE)) {
    if (setup->b_request == USB_REQ_GET_DESCRIPTOR) {
      memcpy(out_read_buffer, func->report_desc_.data(), func->report_desc_.size());
      *out_read_actual = func->report_desc_.size();
      return ZX_OK;
    }
  }
  if (setup->bm_request_type == (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE)) {
    if (setup->b_request == USB_HID_GET_REPORT) {
      memcpy(out_read_buffer, func->report_.data(), func->report_.size());
      *out_read_actual = func->report_.size();
      return ZX_OK;
    }
    if (setup->b_request == USB_HID_GET_PROTOCOL) {
      memcpy(out_read_buffer, &func->hid_protocol_, sizeof(func->hid_protocol_));
      *out_read_actual = sizeof(func->hid_protocol_);
      return ZX_OK;
    }
  }
  if (setup->bm_request_type == (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE)) {
    if (setup->b_request == USB_HID_SET_REPORT) {
      memcpy(func->report_.data(), write_buffer, func->report_.size());
      return ZX_OK;
    }
    if (setup->b_request == USB_HID_SET_PROTOCOL) {
      func->hid_protocol_ = static_cast<fhidbus::wire::HidProtocol>(setup->w_value);
      return ZX_OK;
    }
  }
  return ZX_ERR_IO_REFUSED;
}

zx_status_t FakeUsbHidFunction::UsbFunctionInterfaceSetConfigured(void* ctx, bool configured,
                                                                  usb_speed_t speed) {
  return ZX_OK;
}
zx_status_t FakeUsbHidFunction::UsbFunctionInterfaceSetInterface(void* ctx, uint8_t interface,
                                                                 uint8_t alt_setting) {
  return ZX_OK;
}

zx::result<> FakeUsbHidFunction::Start() {
  zx::result function = compat::ConnectBanjo<ddk::UsbFunctionProtocolClient>(incoming());
  if (function.is_error()) {
    fdf::error("could not connect to UsbFunctionProtocol: {}", function);
    return function.take_error();
  }
  function_ = *function;

  report_desc_.resize(sizeof(boot_mouse_r_desc));
  memcpy(report_desc_.data(), &boot_mouse_r_desc, sizeof(boot_mouse_r_desc));
  report_.resize(3);

  descriptor_size_ = sizeof(fake_usb_hid_descriptor_t) + sizeof(usb_hid_descriptor_entry_t);
  descriptor_.reset(static_cast<fake_usb_hid_descriptor_t*>(calloc(1, descriptor_size_)));
  descriptor_->interface = {
      .b_length = sizeof(usb_interface_descriptor_t),
      .b_descriptor_type = USB_DT_INTERFACE,
      .b_interface_number = 0,
      .b_alternate_setting = 0,
      .b_num_endpoints = 1,
      .b_interface_class = USB_CLASS_HID,
      .b_interface_sub_class = USB_HID_SUBCLASS_BOOT,
      .b_interface_protocol = USB_HID_PROTOCOL_MOUSE,
      .i_interface = 0,
  };
  descriptor_->interrupt = {
      .b_length = sizeof(usb_endpoint_descriptor_t),
      .b_descriptor_type = USB_DT_ENDPOINT,
      .b_endpoint_address = USB_ENDPOINT_IN,  // set later
      .bm_attributes = USB_ENDPOINT_INTERRUPT,
      .w_max_packet_size = htole16(BULK_MAX_PACKET),
      .b_interval = 8,
  };
  descriptor_->hid_descriptor = {
      .bLength = sizeof(usb_hid_descriptor_t) + sizeof(usb_hid_descriptor_entry_t),
      .bDescriptorType = USB_DT_HID,
      .bcdHID = 0,
      .bCountryCode = 0,
      .bNumDescriptors = 1,
  };
  descriptor_->hid_descriptor.descriptors[0] = {
      .bDescriptorType = 0x22,  // HID TYPE REPORT
      .wDescriptorLength = static_cast<uint16_t>(report_desc_.size()),
  };

  zx_status_t status = function_.AllocInterface(&descriptor_->interface.b_interface_number);
  if (status != ZX_OK) {
    fdf::error("FakeUsbHidFunction: usb_function_alloc_interface failed");
    return zx::error(status);
  }
  status = function_.AllocEp(USB_DIR_IN, &descriptor_->interrupt.b_endpoint_address);
  if (status != ZX_OK) {
    fdf::error("FakeUsbHidFunction: usb_function_alloc_ep failed");
    return zx::error(status);
  }

  fuchsia_driver_framework::DevfsAddArgs devfs_args{};
  std::vector<ffdf::NodeProperty> props{};
  std::vector<ffdf::Offer> offers{};

  zx::result result = AddChild(name(), devfs_args, props, offers);
  if (result.is_error()) {
    fdf::error("AddChild(): {}", result);
    return result.take_error();
  }

  function_.SetInterface(this, &function_interface_ops_);
  return zx::ok();
}

}  // namespace one_endpoint_hid_function

FUCHSIA_DRIVER_EXPORT(one_endpoint_hid_function::FakeUsbHidFunction);