usb: chipidea: core: refine the description for this driver

 * core.c - ChipIdea USB IP core family device controller

 *

 * Copyright (C) 2008 Chipidea - MIPS Technologies, Inc. All rights reserved.

 * Copyright (C) 2020 NXP

 *

 * Author: David Lopo

 */

/*

 * Description: ChipIdea USB IP core family device controller

 *

 * This driver is composed of several blocks:

 * - HW:     hardware interface

 * - DBG:    debug facilities (optional)

 * - UTIL:   utilities

 * - ISR:    interrupts handling

 * - ENDPT:  endpoint operations (Gadget API)

 * - GADGET: gadget operations (Gadget API)

 * - BUS:    bus glue code, bus abstraction layer

 *

 * Compile Options

 * - STALL_IN:  non-empty bulk-in pipes cannot be halted

 *              if defined mass storage compliance succeeds but with warnings

 *              => case 4: Hi >  Dn

 *              => case 5: Hi >  Di

 *              => case 8: Hi <> Do

 *              if undefined usbtest 13 fails

 * - TRACE:     enable function tracing (depends on DEBUG)

 *

 * Main Features

 * - Chapter 9 & Mass Storage Compliance with Gadget File Storage

 * - Chapter 9 Compliance with Gadget Zero (STALL_IN undefined)

 * - Normal & LPM support

 *

 * USBTEST Report

 * - OK: 0-12, 13 (STALL_IN defined) & 14

 * - Not Supported: 15 & 16 (ISO)

 *	   Peter Chen <peter.chen@nxp.com>

 *

 * TODO List

 * - Suspend & Remote Wakeup

 * Main Features:

 * - Four transfers are supported, usbtest is passed

 * - USB Certification for gadget: CH9 and Mass Storage are passed

 * - Low power mode

 * - USB wakeup

 */

#include <linux/delay.h>

#include <linux/device.h>