tracing: move tracing under subsys/

Tracing subsystem is growing and although related to debugging, it does
deserve to belong into its own subsystem.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

subsys/tracing/tracing_backend_usb.c

@@ -0,0 +1,184 @@
+/*
+ * Copyright (c) 2019 Intel corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <sys/util.h>
+#include <sys/atomic.h>
+#include <sys/__assert.h>
+#include <sys/byteorder.h>
+#include <usb/usb_device.h>
+#include <usb/usb_common.h>
+#include <usb_descriptor.h>
+#include <tracing_core.h>
+#include <tracing_buffer.h>
+#include <tracing_backend.h>
+
+#define USB_TRANSFER_ONGOING               1
+#define USB_TRANSFER_FREE                  0
+
+#define TRACING_IF_IN_EP_ADDR              0x81
+#define TRACING_IF_OUT_EP_ADDR             0x01
+
+struct usb_device_desc {
+	struct usb_if_descriptor if0;
+	struct usb_ep_descriptor if0_in_ep;
+	struct usb_ep_descriptor if0_out_ep;
+} __packed;
+
+static volatile int transfer_state;
+static enum usb_dc_status_code usb_device_status = USB_DC_UNKNOWN;
+
+USBD_CLASS_DESCR_DEFINE(primary, 0) struct usb_device_desc dev_desc = {
+	/*
+	 * Interface descriptor 0
+	 */
+	.if0 = {
+		.bLength = sizeof(struct usb_if_descriptor),
+		.bDescriptorType = USB_INTERFACE_DESC,
+		.bInterfaceNumber = 0,
+		.bAlternateSetting = 0,
+		.bNumEndpoints = 2,
+		.bInterfaceClass = CUSTOM_CLASS,
+		.bInterfaceSubClass = 0,
+		.bInterfaceProtocol = 0,
+		.iInterface = 0,
+	},
+
+	/*
+	 * Data Endpoint IN
+	 */
+	.if0_in_ep = {
+		.bLength = sizeof(struct usb_ep_descriptor),
+		.bDescriptorType = USB_ENDPOINT_DESC,
+		.bEndpointAddress = TRACING_IF_IN_EP_ADDR,
+		.bmAttributes = USB_DC_EP_BULK,
+		.wMaxPacketSize = sys_cpu_to_le16(CONFIG_TRACING_USB_MPS),
+		.bInterval = 0x00,
+	},
+
+	/*
+	 * Data Endpoint OUT
+	 */
+	.if0_out_ep = {
+		.bLength = sizeof(struct usb_ep_descriptor),
+		.bDescriptorType = USB_ENDPOINT_DESC,
+		.bEndpointAddress = TRACING_IF_OUT_EP_ADDR,
+		.bmAttributes = USB_DC_EP_BULK,
+		.wMaxPacketSize = sys_cpu_to_le16(CONFIG_TRACING_USB_MPS),
+		.bInterval = 0x00,
+	},
+};
+
+static void dev_status_cb(struct usb_cfg_data *cfg,
+			  enum usb_dc_status_code status,
+			  const u8_t *param)
+{
+	ARG_UNUSED(cfg);
+	ARG_UNUSED(param);
+
+	usb_device_status = status;
+}
+
+static void tracing_ep_out_cb(u8_t ep, enum usb_dc_ep_cb_status_code ep_status)
+{
+	u8_t *cmd = NULL;
+	u32_t bytes_to_read, length;
+
+	usb_read(ep, NULL, 0, &bytes_to_read);
+
+	while (bytes_to_read) {
+		length = tracing_cmd_buffer_alloc(&cmd);
+		if (cmd) {
+			length = MIN(length, bytes_to_read);
+			usb_read(ep, cmd, length, NULL);
+			tracing_cmd_handle(cmd, length);
+
+			bytes_to_read -= length;
+		}
+	}
+
+	/*
+	 * send ZLP to sync with host receive thread
+	 */
+	usb_write(TRACING_IF_IN_EP_ADDR, NULL, 0, NULL);
+}
+
+static void tracing_ep_in_cb(u8_t ep, enum usb_dc_ep_cb_status_code ep_status)
+{
+	ARG_UNUSED(ep);
+	ARG_UNUSED(ep_status);
+
+	transfer_state = USB_TRANSFER_FREE;
+}
+
+static struct usb_ep_cfg_data ep_cfg[] = {
+	{
+		.ep_cb = tracing_ep_out_cb,
+		.ep_addr = TRACING_IF_OUT_EP_ADDR,
+	},
+	{
+		.ep_cb = tracing_ep_in_cb,
+		.ep_addr = TRACING_IF_IN_EP_ADDR,
+	},
+};
+
+USBD_CFG_DATA_DEFINE(primary, tracing_backend_usb)
+	struct usb_cfg_data tracing_backend_usb_config = {
+	.usb_device_description = NULL,
+	.interface_descriptor = &dev_desc.if0,
+	.cb_usb_status = dev_status_cb,
+	.interface = {
+		.class_handler = NULL,
+		.custom_handler = NULL,
+		.vendor_handler = NULL,
+	},
+	.num_endpoints = ARRAY_SIZE(ep_cfg),
+	.endpoint = ep_cfg,
+};
+
+static void tracing_backend_usb_output(const struct tracing_backend *backend,
+				       u8_t *data, u32_t length)
+{
+	int ret = 0;
+	u32_t bytes;
+
+	while (length > 0) {
+		transfer_state = USB_TRANSFER_ONGOING;
+
+		/*
+		 * make sure every USB tansfer no need ZLP at all
+		 * because we are in lowest priority thread content
+		 * there are no deterministic time between real USB
+		 * packet and ZLP
+		 */
+		ret = usb_write(TRACING_IF_IN_EP_ADDR, data,
+				length >= CONFIG_TRACING_USB_MPS ?
+				CONFIG_TRACING_USB_MPS - 1 : length, &bytes);
+		if (ret) {
+			continue;
+		}
+
+		data += bytes;
+		length -= bytes;
+
+		while (transfer_state == USB_TRANSFER_ONGOING) {
+		}
+	}
+}
+
+static void tracing_backend_usb_init(void)
+{
+	int ret;
+
+	ret = usb_enable(NULL);
+	__ASSERT(ret == 0, "usb backend enable failed");
+}
+
+const struct tracing_backend_api tracing_backend_usb_api = {
+	.init = tracing_backend_usb_init,
+	.output = tracing_backend_usb_output
+};
+
+TRACING_BACKEND_DEFINE(tracing_backend_usb, tracing_backend_usb_api);