// SPDX-License-Identifier: GPL-2.0
/*
 * Common USB debugging functions
 *
 * Copyright (C) 2010-2011 Texas Instruments Incorporated - https://www.ti.com
 *
 * Authors: Felipe Balbi <balbi@ti.com>,
 *          Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 */

#include <linux/kernel.h>
#include <linux/usb/ch9.h>

static void usb_decode_get_status(__u8 bRequestType, __u16 wIndex,
                                  __u16 wLength, char *str, size_t size)
{
        switch (bRequestType & USB_RECIP_MASK) {
        case USB_RECIP_DEVICE:
                snprintf(str, size, "Get Device Status(Length = %d)", wLength);
                break;
        case USB_RECIP_INTERFACE:
                snprintf(str, size,
                         "Get Interface Status(Intf = %d, Length = %d)",
                         wIndex, wLength);
                break;
        case USB_RECIP_ENDPOINT:
                snprintf(str, size, "Get Endpoint Status(ep%d%s)",
                         wIndex & ~USB_DIR_IN,
                         wIndex & USB_DIR_IN ? "in" : "out");
                break;
        }
}

static const char *usb_decode_device_feature(u16 wValue)
{
        switch (wValue) {
        case USB_DEVICE_SELF_POWERED:
                return "Self Powered";
        case USB_DEVICE_REMOTE_WAKEUP:
                return "Remote Wakeup";
        case USB_DEVICE_TEST_MODE:
                return "Test Mode";
        case USB_DEVICE_U1_ENABLE:
                return "U1 Enable";
        case USB_DEVICE_U2_ENABLE:
                return "U2 Enable";
        case USB_DEVICE_LTM_ENABLE:
                return "LTM Enable";
        default:
                return "UNKNOWN";
        }
}

static const char *usb_decode_test_mode(u16 wIndex)
{
        switch (wIndex) {
        case USB_TEST_J:
                return ": TEST_J";
        case USB_TEST_K:
                return ": TEST_K";
        case USB_TEST_SE0_NAK:
                return ": TEST_SE0_NAK";
        case USB_TEST_PACKET:
                return ": TEST_PACKET";
        case USB_TEST_FORCE_ENABLE:
                return ": TEST_FORCE_EN";
        default:
                return ": UNKNOWN";
        }
}

static void usb_decode_set_clear_feature(__u8 bRequestType,
                                         __u8 bRequest, __u16 wValue,
                                         __u16 wIndex, char *str, size_t size)
{
        switch (bRequestType & USB_RECIP_MASK) {
        case USB_RECIP_DEVICE:
                snprintf(str, size, "%s Device Feature(%s%s)",
                         bRequest == USB_REQ_CLEAR_FEATURE ? "Clear" : "Set",
                         usb_decode_device_feature(wValue),
                         wValue == USB_DEVICE_TEST_MODE ?
                         usb_decode_test_mode(wIndex) : "");
                break;
        case USB_RECIP_INTERFACE:
                snprintf(str, size, "%s Interface Feature(%s)",
                         bRequest == USB_REQ_CLEAR_FEATURE ? "Clear" : "Set",
                         wValue == USB_INTRF_FUNC_SUSPEND ?
                         "Function Suspend" : "UNKNOWN");
                break;
        case USB_RECIP_ENDPOINT:
                snprintf(str, size, "%s Endpoint Feature(%s ep%d%s)",
                         bRequest == USB_REQ_CLEAR_FEATURE ? "Clear" : "Set",
                         wValue == USB_ENDPOINT_HALT ? "Halt" : "UNKNOWN",
                         wIndex & ~USB_DIR_IN,
                         wIndex & USB_DIR_IN ? "in" : "out");
                break;
        }
}

static void usb_decode_set_address(__u16 wValue, char *str, size_t size)
{
        snprintf(str, size, "Set Address(Addr = %02x)", wValue);
}

static void usb_decode_get_set_descriptor(__u8 bRequestType, __u8 bRequest,
                                          __u16 wValue, __u16 wIndex,
                                          __u16 wLength, char *str, size_t size)
{
        char *s;

        switch (wValue >> 8) {
        case USB_DT_DEVICE:
                s = "Device";
                break;
        case USB_DT_CONFIG:
                s = "Configuration";
                break;
        case USB_DT_STRING:
                s = "String";
                break;
        case USB_DT_INTERFACE:
                s = "Interface";
                break;
        case USB_DT_ENDPOINT:
                s = "Endpoint";
                break;
        case USB_DT_DEVICE_QUALIFIER:
                s = "Device Qualifier";
                break;
        case USB_DT_OTHER_SPEED_CONFIG:
                s = "Other Speed Config";
                break;
        case USB_DT_INTERFACE_POWER:
                s = "Interface Power";
                break;
        case USB_DT_OTG:
                s = "OTG";
                break;
        case USB_DT_DEBUG:
                s = "Debug";
                break;
        case USB_DT_INTERFACE_ASSOCIATION:
                s = "Interface Association";
                break;
        case USB_DT_BOS:
                s = "BOS";
                break;
        case USB_DT_DEVICE_CAPABILITY:
                s = "Device Capability";
                break;
        case USB_DT_PIPE_USAGE:
                s = "Pipe Usage";
                break;
        case USB_DT_SS_ENDPOINT_COMP:
                s = "SS Endpoint Companion";
                break;
        case USB_DT_SSP_ISOC_ENDPOINT_COMP:
                s = "SSP Isochronous Endpoint Companion";
                break;
        default:
                s = "UNKNOWN";
                break;
        }

        snprintf(str, size, "%s %s Descriptor(Index = %d, Length = %d)",
                bRequest == USB_REQ_GET_DESCRIPTOR ? "Get" : "Set",
                s, wValue & 0xff, wLength);
}

static void usb_decode_get_configuration(__u16 wLength, char *str, size_t size)
{
        snprintf(str, size, "Get Configuration(Length = %d)", wLength);
}

static void usb_decode_set_configuration(__u8 wValue, char *str, size_t size)
{
        snprintf(str, size, "Set Configuration(Config = %d)", wValue);
}

static void usb_decode_get_intf(__u16 wIndex, __u16 wLength, char *str,
                                size_t size)
{
        snprintf(str, size, "Get Interface(Intf = %d, Length = %d)",
                 wIndex, wLength);
}

static void usb_decode_set_intf(__u8 wValue, __u16 wIndex, char *str,
                                size_t size)
{
        snprintf(str, size, "Set Interface(Intf = %d, Alt.Setting = %d)",
                 wIndex, wValue);
}

static void usb_decode_synch_frame(__u16 wIndex, __u16 wLength,
                                   char *str, size_t size)
{
        snprintf(str, size, "Synch Frame(Endpoint = %d, Length = %d)",
                 wIndex, wLength);
}

static void usb_decode_set_sel(__u16 wLength, char *str, size_t size)
{
        snprintf(str, size, "Set SEL(Length = %d)", wLength);
}

static void usb_decode_set_isoch_delay(__u8 wValue, char *str, size_t size)
{
        snprintf(str, size, "Set Isochronous Delay(Delay = %d ns)", wValue);
}

static void usb_decode_ctrl_generic(char *str, size_t size, __u8 bRequestType,
                                    __u8 bRequest, __u16 wValue, __u16 wIndex,
                                    __u16 wLength)
{
        u8 recip = bRequestType & USB_RECIP_MASK;
        u8 type = bRequestType & USB_TYPE_MASK;

        snprintf(str, size,
                 "Type=%s Recipient=%s Dir=%s bRequest=%u wValue=%u wIndex=%u wLength=%u",
                 (type == USB_TYPE_STANDARD)    ? "Standard" :
                 (type == USB_TYPE_VENDOR)      ? "Vendor" :
                 (type == USB_TYPE_CLASS)       ? "Class" : "Unknown",
                 (recip == USB_RECIP_DEVICE)    ? "Device" :
                 (recip == USB_RECIP_INTERFACE) ? "Interface" :
                 (recip == USB_RECIP_ENDPOINT)  ? "Endpoint" : "Unknown",
                 (bRequestType & USB_DIR_IN)    ? "IN" : "OUT",
                 bRequest, wValue, wIndex, wLength);
}

static void usb_decode_ctrl_standard(char *str, size_t size, __u8 bRequestType,
                                     __u8 bRequest, __u16 wValue, __u16 wIndex,
                                     __u16 wLength)
{
        switch (bRequest) {
        case USB_REQ_GET_STATUS:
                usb_decode_get_status(bRequestType, wIndex, wLength, str, size);
                break;
        case USB_REQ_CLEAR_FEATURE:
        case USB_REQ_SET_FEATURE:
                usb_decode_set_clear_feature(bRequestType, bRequest, wValue,
                                             wIndex, str, size);
                break;
        case USB_REQ_SET_ADDRESS:
                usb_decode_set_address(wValue, str, size);
                break;
        case USB_REQ_GET_DESCRIPTOR:
        case USB_REQ_SET_DESCRIPTOR:
                usb_decode_get_set_descriptor(bRequestType, bRequest, wValue,
                                              wIndex, wLength, str, size);
                break;
        case USB_REQ_GET_CONFIGURATION:
                usb_decode_get_configuration(wLength, str, size);
                break;
        case USB_REQ_SET_CONFIGURATION:
                usb_decode_set_configuration(wValue, str, size);
                break;
        case USB_REQ_GET_INTERFACE:
                usb_decode_get_intf(wIndex, wLength, str, size);
                break;
        case USB_REQ_SET_INTERFACE:
                usb_decode_set_intf(wValue, wIndex, str, size);
                break;
        case USB_REQ_SYNCH_FRAME:
                usb_decode_synch_frame(wIndex, wLength, str, size);
                break;
        case USB_REQ_SET_SEL:
                usb_decode_set_sel(wLength, str, size);
                break;
        case USB_REQ_SET_ISOCH_DELAY:
                usb_decode_set_isoch_delay(wValue, str, size);
                break;
        default:
                usb_decode_ctrl_generic(str, size, bRequestType, bRequest,
                                        wValue, wIndex, wLength);
                break;
        }
}

/**
 * usb_decode_ctrl - Returns human readable representation of control request.
 * @str: buffer to return a human-readable representation of control request.
 *       This buffer should have about 200 bytes.
 * @size: size of str buffer.
 * @bRequestType: matches the USB bmRequestType field
 * @bRequest: matches the USB bRequest field
 * @wValue: matches the USB wValue field (CPU byte order)
 * @wIndex: matches the USB wIndex field (CPU byte order)
 * @wLength: matches the USB wLength field (CPU byte order)
 *
 * Function returns decoded, formatted and human-readable description of
 * control request packet.
 *
 * The usage scenario for this is for tracepoints, so function as a return
 * use the same value as in parameters. This approach allows to use this
 * function in TP_printk
 *
 * Important: wValue, wIndex, wLength parameters before invoking this function
 * should be processed by le16_to_cpu macro.
 */
const char *usb_decode_ctrl(char *str, size_t size, __u8 bRequestType,
                            __u8 bRequest, __u16 wValue, __u16 wIndex,
                            __u16 wLength)
{
        switch (bRequestType & USB_TYPE_MASK) {
        case USB_TYPE_STANDARD:
                usb_decode_ctrl_standard(str, size, bRequestType, bRequest,
                                         wValue, wIndex, wLength);
                break;
        case USB_TYPE_VENDOR:
        case USB_TYPE_CLASS:
        default:
                usb_decode_ctrl_generic(str, size, bRequestType, bRequest,
                                        wValue, wIndex, wLength);
                break;
        }

        return str;
}
EXPORT_SYMBOL_GPL(usb_decode_ctrl);