/*
 * CAMTP Responder
 * Copyright (c) 2020 Holdtecs Technologies
 *
 * CAMTP Responder is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 3.0 of the License, or (at your option) any later version.
 *
 * CAMTP Responder is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License version 3 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with CAMTP Responder; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

/**
 * @file   usb_gadget.c
 * @brief  USB gadget layer
 * @author ***
 */

#ifndef _INC_USB_GADGET_H_
#define _INC_USB_GADGET_H_

#include <linux/usb/ch9.h>
#include <linux/usb/gadgetfs.h>
#include <linux/usb/functionfs.h>

#include "usbstring.h"

enum
{
	EP_DESCRIPTOR_IN = 0,
	EP_DESCRIPTOR_OUT,
	EP_DESCRIPTOR_INT_IN,

	EP_NB_OF_DESCRIPTORS
};

#define EP_INT_MODE  0x00000000
#define EP_BULK_MODE 0x00000001
#define EP_IN_DIR    0x00000000
#define EP_OUT_DIR   0x00000002
#define EP_HS_MODE   0x00000004
#define EP_SS_MODE   0x00000008

typedef struct _EndPointsDesc {
	struct usb_interface_descriptor         if_desc;
	struct usb_endpoint_descriptor_no_audio ep_desc_in;
	struct usb_endpoint_descriptor_no_audio ep_desc_out;
	struct usb_endpoint_descriptor_no_audio ep_desc_int_in;
} __attribute__((packed)) EndPointsDesc;

typedef struct _SSEndPointsDesc {
	struct usb_interface_descriptor         if_desc;
	struct usb_endpoint_descriptor_no_audio ep_desc_in;
	struct usb_ss_ep_comp_descriptor        ep_desc_in_comp;
	struct usb_endpoint_descriptor_no_audio ep_desc_out;
	struct usb_ss_ep_comp_descriptor        ep_desc_out_comp;
	struct usb_endpoint_descriptor_no_audio ep_desc_int_in;
	struct usb_ss_ep_comp_descriptor        ep_desc_int_in_comp;

} __attribute__((packed)) SSEndPointsDesc;

typedef struct ep_cfg_descriptor {
	struct usb_endpoint_descriptor_no_audio ep_desc;
#ifdef CONFIG_USB_SS_SUPPORT
	struct usb_ss_ep_comp_descriptor        ep_desc_comp;
#endif
} __attribute__((packed)) ep_cfg_descriptor;

// Direct GadgetFS mode
typedef struct _usb_cfg
{
	uint32_t head;

#if CONFIG_USB_FS_SUPPORT
	struct usb_config_descriptor cfg_fs;
	EndPointsDesc ep_desc_fs;
#endif

#if CONFIG_USB_HS_SUPPORT
	struct usb_config_descriptor cfg_hs;
	EndPointsDesc ep_desc_hs;
#endif

#if CONFIG_USB_SS_SUPPORT
	struct usb_config_descriptor cfg_ss;
	SSEndPointsDesc ep_desc_ss;
#endif

	struct usb_device_descriptor dev_desc;

} __attribute__ ((packed)) usb_cfg;

// FunctionFS mode
typedef struct _usb_ffs_cfg
{
	uint32_t magic;
	uint32_t length;
#ifndef OLD_FUNCTIONFS_DESCRIPTORS // Kernel > v3.14
	uint32_t flags;
#endif

#ifdef CONFIG_USB_FS_SUPPORT
	uint32_t fs_count;
#endif

#ifdef CONFIG_USB_HS_SUPPORT
	uint32_t hs_count;
#endif

#if defined(CONFIG_USB_SS_SUPPORT) && !defined(OLD_FUNCTIONFS_DESCRIPTORS)
	uint32_t ss_count;
#endif

#ifdef CONFIG_USB_FS_SUPPORT
	EndPointsDesc ep_desc_fs;
#endif

#ifdef CONFIG_USB_HS_SUPPORT
	EndPointsDesc ep_desc_hs;
#endif

#if defined(CONFIG_USB_SS_SUPPORT) && !defined(OLD_FUNCTIONFS_DESCRIPTORS)
	SSEndPointsDesc ep_desc_ss;
#endif

} __attribute__ ((packed)) usb_ffs_cfg;

typedef struct _ffs_strings
{
	struct usb_functionfs_strings_head header;
	uint16_t code;
	char string_data[128]; // string data.
} __attribute__((packed)) ffs_strings;

typedef struct _ep_cfg
{
	uint32_t head;

	ep_cfg_descriptor ep_desc[2];

} __attribute__ ((packed)) ep_cfg;

enum {
	STRINGID_MANUFACTURER = 1,
	STRINGID_PRODUCT,
	STRINGID_SERIAL,
	STRINGID_CONFIG_HS,
	STRINGID_CONFIG_LS,
	STRINGID_INTERFACE,
	STRINGID_MAX
};

#define MAX_USB_STRING 16

typedef struct _usb_gadget
{
	int 		usb_device;
	int 		ep_handles[EP_NB_OF_DESCRIPTORS];

	usb_cfg 	*usb_config;
	usb_ffs_cfg *usb_ffs_config;

	ep_cfg		*ep_config[EP_NB_OF_DESCRIPTORS];
	char		*ep_path[EP_NB_OF_DESCRIPTORS];

	struct usb_string stringtab[MAX_USB_STRING];
}usb_gadget;

#endif