Add WebUSB descriptor support

The WebUSB specification defines a specific Platform Descriptor in the
Binary Object Store:
https://wicg.github.io/webusb/#webusb-platform-capability-descriptor
This descriptor provides a special 'Landing page' URL to the host
browser and associated privileges for it.

Bump the USB version for BOS descriptors to 2.1 to be compatible with
Chrome implementation.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BUG=none
BRANCH=twinkie
TEST=manual: on Twinkie (chip/stm32) and HG proto2 (chip/g), enumerate
WebUSB descriptors with lsusb and connect to a WebUSB page in Chrome
R61+.

Change-Id: I7211ab554f4a6c156c1e8e79a3d9f0d6644217c6
Reviewed-on: https://chromium-review.googlesource.com/664813
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/common/webusb_desc.c b/common/webusb_desc.c
new file mode 100644
index 0000000000..41d39006e0
--- /dev/null
+++ b/common/webusb_desc.c
@@ -0,0 +1,46 @@
+/* Copyright 2017 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+/* WebUSB platform descriptor */
+
+#include "common.h"
+#include "usb_descriptor.h"
+#include "util.h"
+
+#ifndef CONFIG_USB_BOS
+#error "CONFIG_USB_BOS must be defined to use WebUSB descriptor"
+#endif
+
+const void *webusb_url = USB_URL_DESC(HTTPS, CONFIG_WEBUSB_URL);
+
+/*
+ * Platform Descriptor in the device Binary Object Store
+ * as defined by USB 3.1 spec chapter 9.6.2.
+ */
+static struct {
+	struct usb_bos_hdr_descriptor bos;
+	struct usb_platform_descriptor platform;
+} bos_desc = {
+	.bos = {
+		.bLength = USB_DT_BOS_SIZE,
+		.bDescriptorType = USB_DT_BOS,
+		.wTotalLength = (USB_DT_BOS_SIZE + USB_DT_PLATFORM_SIZE),
+		.bNumDeviceCaps = 1,  /* platform caps */
+	},
+	.platform = {
+		.bLength = USB_DT_PLATFORM_SIZE,
+		.bDescriptorType = USB_DT_DEVICE_CAPABILITY,
+		.bDevCapabilityType = USB_DC_DTYPE_PLATFORM,
+		.bReserved = 0,
+		.PlatformCapUUID = USB_PLAT_CAP_WEBUSB,
+		.bcdVersion = 0x0100,
+		.bVendorCode = 0x01,
+		.iLandingPage = 1,
+	},
+};
+
+const struct bos_context bos_ctx = {
+	.descp = (void *)&bos_desc,
+	.size = sizeof(bos_desc),
+};