/* mbed Microcontroller Library
 * Copyright (c) 2015 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
// math.h required for floating point operations for baud rate calculation
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "serial_api.h"
#include "cmsis.h"
#include "pinmap.h"
#include "PinNames.h"
#include "mbed_error.h"
#include "gpio_api.h"

/******************************************************************************
 * INITIALIZATION
 ******************************************************************************/

static const PinMap PinMap_UART_TX[] = {
    {UART_TX0, UART_0, 0},
    {UART_TX1, UART_1, 0},
    {NC, NC, 0}
};

static const PinMap PinMap_UART_RX[] = {
    {UART_RX0, UART_0, 0},
    {UART_RX1, UART_1, 0},
    {NC, NC, 0}
};

#define UART_NUM 2

static uart_irq_handler irq_handler;

int stdio_uart_inited = 0;
serial_t stdio_uart;

struct serial_global_data_s {
    uint32_t serial_irq_id;
    gpio_t sw_rts, sw_cts;
    uint8_t count, rx_irq_set_flow, rx_irq_set_api;
};

static struct serial_global_data_s uart_data[UART_NUM];

void serial_init(serial_t *obj, PinName tx, PinName rx) {
    int is_stdio_uart = 0;

    // determine the UART to use
    UARTName uart_tx = (UARTName)pinmap_peripheral(tx, PinMap_UART_TX);
    UARTName uart_rx = (UARTName)pinmap_peripheral(rx, PinMap_UART_RX);
    UARTName uart = (UARTName)pinmap_merge(uart_tx, uart_rx);
    if ((int)uart == NC) {
        error("Serial pinout mapping failed");
    }

    obj->uart = (CMSDK_UART_TypeDef *)uart;
    //set baud rate and enable Uart in normarl mode (RX and TX enabled)
    switch (uart) {
        case UART_0:
            {
                CMSDK_UART0->CTRL = 0; // Disable UART when changing configuration
                if ((int)tx != NC) {
                    CMSDK_UART0->CTRL = 0x1; // TX enable
                }
                if ((int)rx != NC) {
                    CMSDK_UART0->CTRL |= 0x2; // RX enable
                }
            }
            break;
        case UART_1:
            {
                CMSDK_UART1->CTRL = 0; // Disable UART when changing configuration
                if((int)tx != NC) {
                    CMSDK_UART1->CTRL = 0x1; // TX enable
                }
                if((int)rx != NC) {
                    CMSDK_UART1->CTRL |= 0x2; // RX enable
                }
            }
            break;
    }

    // set default baud rate and format
    serial_baud(obj, 9600);

    // pinout the chosen uart
    pinmap_pinout(tx, PinMap_UART_TX);
    pinmap_pinout(rx, PinMap_UART_RX);

    switch (uart) {
        case UART_0:
            obj->index = 0;
            break;
        case UART_1:
            obj->index = 1;
            break;
    }
    uart_data[obj->index].sw_rts.pin = NC;
    uart_data[obj->index].sw_cts.pin = NC;
    serial_set_flow_control(obj, FlowControlNone, NC, NC);

    is_stdio_uart = (uart == STDIO_UART) ? (1) : (0);

    if (is_stdio_uart) {
        stdio_uart_inited = 1;
        memcpy(&stdio_uart, obj, sizeof(serial_t));
    }
}

void serial_free(serial_t *obj) {
    uart_data[obj->index].serial_irq_id = 0;
}

// serial_baud
// set the baud rate, taking in to account the current SystemFrequency
void serial_baud(serial_t *obj, int baudrate) {
    // BEETLE has a simple divider to control the baud rate. The formula is:
    //
    // Baudrate = PCLK / BAUDDIV
    //
    // PCLK = SystemCoreClock
    // so for a desired baud rate of 9600
    // SystemCoreClock / 9600
    //
    //check to see if minimum baud value entered
    int baudrate_div = 0;
    baudrate_div = SystemCoreClock / baudrate;
    if (baudrate >= 16) {
        switch ((int)obj->uart) {
            case UART_0:
                CMSDK_UART0->BAUDDIV = baudrate_div;
                break;
            case UART_1:
                CMSDK_UART1->BAUDDIV = baudrate_div;
                break;
            default:
                error("serial_baud");
                break;
        }
    } else {
        error("serial_baud");
    }

}

void serial_format(serial_t *obj, int data_bits,
        SerialParity parity, int stop_bits) {
}

/******************************************************************************
 * INTERRUPTS HANDLING
 ******************************************************************************/
static inline void uart_irq(uint32_t intstatus, uint32_t index,
        CMSDK_UART_TypeDef *puart) {
    SerialIrq irq_type;
    switch (intstatus) {
        case 1:
            {
                irq_type = TxIrq;
            }
            break;

        case 2:
            {
                irq_type = RxIrq;
            }
            break;

        default: return;
    }   /* End of Switch */

    if ((irq_type == RxIrq) && (NC != uart_data[index].sw_rts.pin)) {
        gpio_write(&uart_data[index].sw_rts, 1);
        // Disable interrupt if it wasn't enabled by other part of the application
        if (!uart_data[index].rx_irq_set_api) {
            // puart->CTRL &= ~(1 << RxIrq);
            /* Disable Rx interrupt */
            puart->CTRL &= ~(CMSDK_UART_CTRL_RXIRQEN_Msk);
        }
    }

    if (uart_data[index].serial_irq_id != 0) {
        if ((irq_type != RxIrq) || (uart_data[index].rx_irq_set_api)) {
            irq_handler(uart_data[index].serial_irq_id, irq_type);
        }
    }

    if( irq_type == TxIrq ) {
        /* Clear the TX interrupt Flag */
        puart->INTCLEAR |= 0x01;
    } else {
        /* Clear the Rx interupt Flag */
        puart->INTCLEAR |= 0x02;
    }
}

void uart0_irq() {
    uart_irq(CMSDK_UART0->INTSTATUS & 0x3, 0,
        (CMSDK_UART_TypeDef*)CMSDK_UART0);
}

void uart1_irq() {
    uart_irq(CMSDK_UART1->INTSTATUS & 0x3, 1,
        (CMSDK_UART_TypeDef*)CMSDK_UART1);
}

void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id) {
    irq_handler = handler;
    uart_data[obj->index].serial_irq_id = id;
}

static void serial_irq_set_internal(serial_t *obj, SerialIrq irq, uint32_t enable) {
    /* Declare a variable of type IRQn, initialise to 0 */
    IRQn_Type irq_n = (IRQn_Type)0;
    uint32_t vector = 0;
    switch ((int)obj->uart) {

        /*********************************************************************
         *                  BEETLE SOC BOARD                                 *
         *********************************************************************/
        case UART_0:
            {
                irq_n = UART0_IRQn;
                vector = (uint32_t)&uart0_irq;
            }
            break;
        case UART_1:
            {
                irq_n = UART1_IRQn;
                vector = (uint32_t)&uart1_irq;
            }
            break;
    }

    if (enable) {
        if(irq == TxIrq) {
            /* Transmit IRQ, set appripriate enable */

            /* set TX interrupt enable in CTRL REG */
            obj->uart->CTRL |= CMSDK_UART_CTRL_TXIRQEN_Msk;
        } else {
            /* set Rx interrupt on in CTRL REG */
            obj->uart->CTRL |= CMSDK_UART_CTRL_RXIRQEN_Msk;
        }
        NVIC_SetVector(irq_n, vector);
        NVIC_EnableIRQ(irq_n);

    } else if ((irq == TxIrq) || (uart_data[obj->index].rx_irq_set_api
                    + uart_data[obj->index].rx_irq_set_flow == 0)) {
        /*      Disable   IRQ   */
        int all_disabled = 0;
        SerialIrq other_irq = (irq == RxIrq) ? (TxIrq) : (RxIrq);

        obj->uart->CTRL &= ~(1 << (irq + 2));

        all_disabled = (obj->uart->CTRL & (1 << (other_irq + 2))) == 0;

        if (all_disabled) {
            NVIC_DisableIRQ(irq_n);
        }
    }
}

void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable) {
    if (RxIrq == irq)
        uart_data[obj->index].rx_irq_set_api = enable;
    serial_irq_set_internal(obj, irq, enable);
}

/******************************************************************************
 * READ/WRITE
 ******************************************************************************/
int serial_getc(serial_t *obj) {
    while (serial_readable(obj) == 0);
    int data = obj->uart->DATA;
    return data;
}

void serial_putc(serial_t *obj, int c) {
#ifdef SERIAL_TEST
    // Add CR to LF
    if (c == 0x0A) {
        while (serial_writable(obj));
        obj->uart->DATA = 0x0D;
    }
#endif

    while (serial_writable(obj));
    obj->uart->DATA = c;
}

int serial_readable(serial_t *obj) {
    return obj->uart->STATE & 2;
}

int serial_writable(serial_t *obj) {
    return obj->uart->STATE & 1;
}

void serial_clear(serial_t *obj) {
    obj->uart->DATA = 0x00;
}

void serial_pinout_tx(PinName tx) {
    pinmap_pinout(tx, PinMap_UART_TX);
}

void serial_break_set(serial_t *obj) {
}

void serial_break_clear(serial_t *obj) {
}
void serial_set_flow_control(serial_t *obj, FlowControl type,
        PinName rxflow, PinName txflow) {
}