zircon/system/dev/input/usb-hid/usb-hid-function.cpp

// 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 "usb-hid-function.h"

#include <assert.h>
#include <memory>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <ddk/binding.h>
#include <ddk/debug.h>
#include <ddk/driver.h>
#include <ddk/metadata.h>
#include <ddk/platform-defs.h>
#include <fbl/algorithm.h>
#include <usb/usb-request.h>
#include <zircon/device/usb-peripheral.h>
#include <zircon/process.h>
#include <zircon/syscalls.h>

namespace usb_hid_function {

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, void* 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 void* write_buffer, size_t write_size,
                                                            void* out_read_buffer, size_t read_size,
                                                            size_t* out_read_actual) {
    FakeUsbHidFunction* func = static_cast<FakeUsbHidFunction*>(ctx);

    if (setup->bmRequestType == (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE)) {
        if (setup->bRequest == 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->bmRequestType == (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE)) {
        if (setup->bRequest == 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->bmRequestType == (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE)) {
        if (setup->bRequest == USB_HID_SET_REPORT) {
            memcpy(func->report_.data(), write_buffer, func->report_.size());
            return ZX_OK;
        }
    }
    if (out_read_actual) {
        *out_read_actual = 0;
    }
    return ZX_OK;
}

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_status_t FakeUsbHidFunction::Bind() {

    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 = {
        .bLength = sizeof(usb_interface_descriptor_t),
        .bDescriptorType = USB_DT_INTERFACE,
        .bInterfaceNumber = 0,
        .bAlternateSetting = 0,
        .bNumEndpoints = 1,
        .bInterfaceClass = USB_CLASS_HID,
        .bInterfaceSubClass = 0,
        .bInterfaceProtocol = 0,
        .iInterface = 0,
    };
    descriptor_->interrupt = {
        .bLength = sizeof(usb_endpoint_descriptor_t),
        .bDescriptorType = USB_DT_ENDPOINT,
        .bEndpointAddress = USB_ENDPOINT_IN, // set later
        .bmAttributes = USB_ENDPOINT_INTERRUPT,
        .wMaxPacketSize = htole16(0x1000),
        .bInterval = 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,
        .descriptors = {},
    };
    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.bInterfaceNumber);
    if (status != ZX_OK) {
        zxlogf(ERROR, "FakeUsbHidFunction: usb_function_alloc_interface failed\n");
        return status;
    }
    status = function_.AllocEp(USB_DIR_IN, &descriptor_->interrupt.bEndpointAddress);
    if (status != ZX_OK) {
        zxlogf(ERROR, "FakeUsbHidFunction: usb_function_alloc_ep failed\n");
        return status;
    }

    status = DdkAdd("usb-hid-function");
    if (status != ZX_OK) {
        return status;
    }
    function_.SetInterface(this, &function_interface_ops_);
    return ZX_OK;
}

void FakeUsbHidFunction::DdkUnbind() {
    DdkRemove();
}

void FakeUsbHidFunction::DdkRelease() {
    delete this;
}

zx_status_t bind(void* ctx, zx_device_t* parent) {
    auto dev = std::make_unique<FakeUsbHidFunction>(parent);
    zx_status_t status = dev->Bind();
    if (status == ZX_OK) {
        // devmgr is now in charge of the memory for dev
        dev.release();
    }
    return ZX_OK;
}
static zx_driver_ops_t driver_ops = []() {
    zx_driver_ops_t ops = {};
    ops.version = DRIVER_OPS_VERSION;
    ops.bind = bind;
    return ops;
}();

} // namespace usb_hid_function

// clang-format off
ZIRCON_DRIVER_BEGIN(usb_hid_function, usb_hid_function::driver_ops, "zircon", "0.1", 2)
    BI_ABORT_IF(NE, BIND_PROTOCOL, ZX_PROTOCOL_USB_FUNCTION),
    BI_MATCH_IF(EQ, BIND_USB_CLASS, USB_CLASS_HID),
ZIRCON_DRIVER_END(usb_hid_function)
    // clang-format on