/**
 ******************************************************************************
 * @addtogroup PIOS PIOS Core hardware abstraction layer
 * @{
 * @addtogroup   PIOS_USB USB Setup Functions
 * @brief PIOS USB device implementation
 * @{
 *
 * @file       pios_usb.c
 * @author     The LibrePilot Project, http://www.librepilot.org (C) 2017.
 *             Tau Labs, http://taulabs.org, Copyright (C) 2012-2013
 *             The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @brief      USB device functions (STM32 dependent code)
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/*
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/* Project Includes */
#include "pios.h"

#if defined(PIOS_INCLUDE_USB)

#include "usb_lib.h"
#include "pios_usb_board_data.h"

#include "pios_usb.h"
#include "pios_usb_priv.h"


/* Rx/Tx status */
static bool transfer_possible = false;

#ifdef PIOS_INCLUDE_FREERTOS
struct {
    void     (*callback)(bool connected, uint32_t context);
    uint32_t context;
} connectionState_cb_list[3];
#endif

/* USB activity detection */
static volatile bool sof_seen_since_reset = false;

enum pios_usb_dev_magic {
    PIOS_USB_DEV_MAGIC = 0x17365904,
};

struct pios_usb_dev {
    enum pios_usb_dev_magic   magic;
    const struct pios_usb_cfg *cfg;
};
#ifdef PIOS_INCLUDE_FREERTOS
static void raiseConnectionStateCallback(bool connected);
#endif

/**
 * @brief Validate the usb device structure
 * @returns 0 if valid device or -1 otherwise
 */
static int32_t PIOS_USB_validate(struct pios_usb_dev *usb_dev)
{
    if (usb_dev == NULL) {
        return -1;
    }

    if (usb_dev->magic != PIOS_USB_DEV_MAGIC) {
        return -1;
    }

    return 0;
}

#ifdef PIOS_INCLUDE_FREERTOS
static struct pios_usb_dev *PIOS_USB_alloc(void)
{
    struct pios_usb_dev *usb_dev;

    usb_dev = (struct pios_usb_dev *)pios_malloc(sizeof(*usb_dev));
    if (!usb_dev) {
        return NULL;
    }

    usb_dev->magic = PIOS_USB_DEV_MAGIC;
    return usb_dev;
}
#else
static struct pios_usb_dev pios_usb_devs[PIOS_USB_MAX_DEVS];
static uint8_t pios_usb_num_devs;
static struct pios_usb_dev *PIOS_USB_alloc(void)
{
    struct pios_usb_dev *usb_dev;

    if (pios_usb_num_devs >= PIOS_USB_MAX_DEVS) {
        return NULL;
    }

    usb_dev = &pios_usb_devs[pios_usb_num_devs++];
    usb_dev->magic = PIOS_USB_DEV_MAGIC;

    return usb_dev;
}
#endif /* ifdef PIOS_INCLUDE_FREERTOS */

/**
 * Initialises USB COM layer
 * \return < 0 if initialisation failed
 * \note Applications shouldn't call this function directly, instead please use \ref PIOS_COM layer functions
 */
static uint32_t pios_usb_com_id;
int32_t PIOS_USB_Init(uint32_t *usb_id, const struct pios_usb_cfg *cfg)
{
    PIOS_Assert(usb_id);
    PIOS_Assert(cfg);

    struct pios_usb_dev *usb_dev;

    usb_dev = (struct pios_usb_dev *)PIOS_USB_alloc();
    if (!usb_dev) {
        goto out_fail;
    }

    /* Bind the configuration to the device instance */
    usb_dev->cfg = cfg;

    PIOS_USB_Reenumerate();

    /*
     * This is a horrible hack to make this available to
     * the interrupt callbacks.  This should go away ASAP.
     */
    pios_usb_com_id = (uintptr_t)usb_dev;

    /* Enable the USB Interrupts */
    NVIC_Init((NVIC_InitTypeDef *)&usb_dev->cfg->irq.init);

    /* Configure USB D-/D+ (DM/DP) pins */
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_11 | GPIO_Pin_12;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource11, GPIO_AF_14);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource12, GPIO_AF_14);

    /* Configure VBUS sense pin */
    if (usb_dev->cfg->vsense.gpio) {
        GPIO_Init(usb_dev->cfg->vsense.gpio, (GPIO_InitTypeDef *)&usb_dev->cfg->vsense.init);
    }

    /* Select USBCLK source */
    RCC_USBCLKConfig(RCC_USBCLKSource_PLLCLK_1Div5);
    /* Enable the USB clock */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USB, ENABLE);

    USB_Init();
    USB_SIL_Init();

    *usb_id = (uintptr_t)usb_dev;

    return 0; /* No error */

out_fail:
    return -1;
}

/**
 * This function is called by the USB driver on cable connection/disconnection
 * \param[in] connected connection status (1 if connected)
 * \return < 0 on errors
 * \note Applications shouldn't call this function directly, instead please use \ref PIOS_COM layer functions
 */
int32_t PIOS_USB_ChangeConnectionState(bool Connected)
{
    // In all cases: re-initialise USB HID driver
    if (Connected) {
        transfer_possible = true;

        // TODO: Check SetEPRxValid(ENDP1);

#if defined(USB_LED_ON)
        USB_LED_ON; // turn the USB led on
#endif
    } else {
        // Cable disconnected: disable transfers
        transfer_possible = false;

#if defined(USB_LED_OFF)
        USB_LED_OFF; // turn the USB led off
#endif
    }

#ifdef PIOS_INCLUDE_FREERTOS
    raiseConnectionStateCallback(Connected);
#endif

    return 0;
}

int32_t PIOS_USB_Reenumerate()
{
    /* Force USB reset and power-down (this will also release the USB pins for direct GPIO control) */
    _SetCNTR(CNTR_FRES | CNTR_PDWN);

    /* Using a "dirty" method to force a re-enumeration: */
    /* Force DPM (Pin PA12) low for ca. 10 mS before USB Tranceiver will be enabled */
    /* This overrules the external Pull-Up at PA12, and at least Windows & MacOS will enumerate again */
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_StructInit(&GPIO_InitStructure);
    GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_12;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_OUT;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    PIOS_DELAY_WaitmS(50);

    /* Release power-down, still hold reset */
    _SetCNTR(CNTR_PDWN);
    PIOS_DELAY_WaituS(5);

    /* CNTR_FRES = 0 */
    _SetCNTR(0);

    /* Clear pending interrupts */
    _SetISTR(0);

    /* set back to alternate function */
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    /* Configure USB clock */
    /* USBCLK = PLLCLK / 1.5 */
    RCC_USBCLKConfig(RCC_USBCLKSource_PLLCLK_1Div5);
    /* Enable USB clock */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USB, ENABLE);

    return 0;
}

bool PIOS_USB_CableConnected(__attribute__((unused)) uint8_t id)
{
    struct pios_usb_dev *usb_dev = (struct pios_usb_dev *)pios_usb_com_id;

    if (PIOS_USB_validate(usb_dev) != 0) {
        return false;
    }

    // If board is configured to have a VSENSE pin, use that
    if (usb_dev->cfg->vsense.gpio != NULL) {
        return GPIO_ReadInputDataBit(usb_dev->cfg->vsense.gpio, usb_dev->cfg->vsense.init.GPIO_Pin) == Bit_SET;
    }

    return sof_seen_since_reset;
}

/**
 * This function returns the connection status of the USB HID interface
 * \return 1: interface available
 * \return 0: interface not available
 * \note Applications shouldn't call this function directly, instead please use \ref PIOS_COM layer functions
 */
bool PIOS_USB_CheckAvailable(uint32_t id)
{
    struct pios_usb_dev *usb_dev = (struct pios_usb_dev *)pios_usb_com_id;

    if (PIOS_USB_validate(usb_dev) != 0) {
        return false;
    }

    return PIOS_USB_CableConnected(id) && transfer_possible;
}

void SOF_Callback(void)
{
    sof_seen_since_reset = true;
}

void SUSP_Callback(void)
{
    sof_seen_since_reset = false;
}

#ifdef PIOS_INCLUDE_FREERTOS
void PIOS_USB_RegisterConnectionStateCallback(void (*connectionStateCallback)(bool connected, uint32_t context), uint32_t context)
{
    PIOS_Assert(connectionStateCallback);

    for (uint32_t i = 0; i < NELEMENTS(connectionState_cb_list); i++) {
        if (connectionState_cb_list[i].callback == NULL) {
            connectionState_cb_list[i].callback = connectionStateCallback;
            connectionState_cb_list[i].context  = context;
            return;
        }
    }

    PIOS_Assert(0);
}

static void raiseConnectionStateCallback(bool connected)
{
    uint32_t i = 0;

    while (i < NELEMENTS(connectionState_cb_list) && connectionState_cb_list[i].callback != NULL) {
        connectionState_cb_list[i].callback(connected, connectionState_cb_list[i].context);
        i++;
    }
}
#else /* PIOS_INCLUDE_FREERTOS */
void PIOS_USB_RegisterConnectionStateCallback(__attribute__((unused)) void (*connectionStateCallback)(bool connected, uint32_t context), __attribute__((unused)) uint32_t context)
{}
#endif /* PIOS_INCLUDE_FREERTOS */

#endif /* if defined(PIOS_INCLUDE_USB) */

/**
 * @}
 * @}
 */