/**************************************************************************//**
 * \brief USART0 library
 * \author Copyright (C) 2011  Julien Le Sech - www.idreammicro.com
 * \version 1.0
 * \date 20090426
 *
 * This file is part of the iDreamMicro library.
 *
 * This library is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option) any
 * later version.
 *
 * This library 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 Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see http://www.gnu.org/licenses/
 ******************************************************************************/
/**************************************************************************//**
 * \file usart0_m128.c
 ******************************************************************************/
/******************************************************************************
 * Header file inclusions.
 ******************************************************************************/
#include "../usart0.h"
#include <usart/usart.h>
#include <useful/bits.h>
#include <avr/interrupt.h>
#include <avr/io.h>
#include <assert.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
/******************************************************************************
 * Private variable declarations.
 ******************************************************************************/
static usart__rx_complete_callback_t
*           p_rx_complete           
= NULL
;
static usart__tx_complete_callback_t
*           p_tx_complete           
= NULL
;
static usart__data_register_empty_callback_t
*   p_data_register_empty   
= NULL
;
static usart__configuration_t configuration 
=
{
    .
mode       = USART__MODE__ASYNCHRONOUS
,
    .
baudrate   = USART__BAUDRATE__9600
,
    .
data_size  = USART__DATA_SIZE__8_BITS
,
    .
stop_size  = USART__STOP_SIZE__1_BIT
,
    .
parity     = USART__PARITY__DISABLED
};
static bool double_speed_is_set 
= false;
/******************************************************************************
 * Private function prototypes.
 ******************************************************************************/
/**************************************************************************//**
 *
 ******************************************************************************/
static inline
uint16_t
usart0__compute_ubrr
(
    void
);
/******************************************************************************
 * Public function definitions.
 ******************************************************************************/
/**************************************************************************//**
 * \fn void usart0__initialize(usart__configuration_t* p_configuration)
 *
 * \brief Initialize USART0.
 *
 * \param[in] p_configuration   USART configuration. If null, default settings
 *                              will be used.
 *
 * Default settings:
 * - baudrate = 9600 bps;
 * - 8 data bits;
 * - 1 stop bit;
 * - no parity.
 ******************************************************************************/
void
usart0__initialize
(
    const usart__configuration_t
* p_configuration
){
    // If p_configuration is not null, use it!
    if (NULL 
!= p_configuration
)
    {
        configuration 
= *p_configuration
;
    }
    // Set mode.
    usart0__set_mode
(configuration.
mode);
    // Set baud rate.
    usart0__set_baudrate
(configuration.
baudrate);
    usart0__set_double_speed
(false);
    // Configure settings.
    usart0__set_data_size
(configuration.
data_size);
    usart0__set_stop_size
(configuration.
stop_size);
    usart0__set_parity
(configuration.
parity);
}
/**************************************************************************//**
 * \fn void usart0__set_baudrate(usart__baudrate_t baudrate)
 *
 * \brief Set USART0 baudrate.
 *
 * \param baudrate baudrate to set (in bauds per second)
 ******************************************************************************/
void
usart0__set_baudrate
(
    usart__baudrate_t baudrate
){
    configuration.
baudrate = baudrate
;
    uint16_t ubrr 
= usart0__compute_ubrr
();
    UBRR0H 
= (uint8_t)(ubrr 
>> 8);
    UBRR0L 
= (uint8_t)ubrr
;
}
/**************************************************************************//**
 * \fn void usart0__set_mode(usart__mode_t usart_mode)
 *
 * \brief Set USART0 mode.
 *
 * \param usart_mode Mode to set.
 ******************************************************************************/
void
usart0__set_mode
(
    usart__mode_t usart_mode
){
    // Check the preconditions.
    assert(USART__MODE__INVALID 
> usart_mode
);
    configuration.
mode = usart_mode
;
    switch (usart_mode
)
    {
        case USART__MODE__ASYNCHRONOUS
:
        {
            BIT__RST
(UCSR0C
, UMSEL0
);
        }
        break;
        case USART__MODE__SYNCHRONOUS
:
        {
            BIT__SET
(UCSR0C
, UMSEL0
);
        }
        break;
        case USART__MODE__MASTER_SPI
:
        case USART__MODE__INVALID
:
        default:
        break;
    }
}
/**************************************************************************//**
 * \fn void usart0__set_data_size(usart__data_sizet data_size)
 *
 * \brief Set USART0 data size.
 *
 * \param data_size data size (in bits)
 ******************************************************************************/
void
usart0__set_data_size
(
    usart__data_size_t data_size
){
    configuration.
data_size = data_size
;
    switch (data_size
)
    {
        case USART__DATA_SIZE__5_BITS
:
        {
            BIT__RST
(UCSR0B
, UCSZ02
);
            BIT__RST
(UCSR0C
, UCSZ01
);
            BIT__RST
(UCSR0C
, UCSZ00
);
        }
        break;
        case USART__DATA_SIZE__6_BITS
:
        {
            BIT__RST
(UCSR0B
, UCSZ02
);
            BIT__RST
(UCSR0C
, UCSZ01
);
            BIT__SET
(UCSR0C
, UCSZ00
);
        }
        break;
        case USART__DATA_SIZE__7_BITS
:
        {
            BIT__RST
(UCSR0B
, UCSZ02
);
            BIT__SET
(UCSR0C
, UCSZ01
);
            BIT__RST
(UCSR0C
, UCSZ00
);
        }
        break;
        case USART__DATA_SIZE__8_BITS
:
        {
            BIT__RST
(UCSR0B
, UCSZ02
);
            BIT__SET
(UCSR0C
, UCSZ01
);
            BIT__SET
(UCSR0C
, UCSZ00
);
        }
        break;
        case USART__DATA_SIZE__9_BITS
:
        {
            BIT__SET
(UCSR0B
, UCSZ02
);
            BIT__SET
(UCSR0C
, UCSZ01
);
            BIT__SET
(UCSR0C
, UCSZ00
);
        }
        break;
        default:
        break;
    }
}
/**************************************************************************//**
 * \fn void usart0__set_stop_size(usart__stop_size_t stop_size)
 *
 * \brief Set USART0 stop size.
 *
 * \param stop_size stop size (in bits)
 ******************************************************************************/
void
usart0__set_stop_size
(
    usart__stop_size_t stop_size
){
    configuration.
stop_size = stop_size
;
    if (USART__STOP_SIZE__1_BIT 
== stop_size
)
    {
        BIT__RST
(UCSR0C
, USBS0
);
    }
    else
    {
        BIT__SET
(UCSR0C
, USBS0
);
    }
}
/**************************************************************************//**
 * \fn void usart0__set_parity(usart__parity_t parity)
 *
 * \brief Set USART0 parity.
 *
 * \param parity parity to set
 ******************************************************************************/
void
usart0__set_parity
(
    usart__parity_t parity
){
    configuration.
parity = parity
;
    switch (parity
)
    {
        case USART__PARITY__DISABLED
:
        {
            BIT__RST
(UCSR0C
, UPM01
);
            BIT__RST
(UCSR0C
, UPM00
);
        }
        break;
        case USART__PARITY__EVEN
:
        {
            BIT__SET
(UCSR0C
, UPM01
);
            BIT__RST
(UCSR0C
, UPM00
);
        }
        break;
        case USART__PARITY__ODD
:
        {
            BIT__SET
(UCSR0C
, UPM01
);
            BIT__SET
(UCSR0C
, UPM00
);
        }
        break;
        default:
        break;
    }
}
/**************************************************************************//**
 * \fn void usart0__set_double_speed(bool double_speed)
 *
 * \brief Set double speed.
 *
 * \param   double_speed    True to set double speed, false otherwise.
 ******************************************************************************/
void
usart0__set_double_speed
(
    bool double_speed
){
    double_speed_is_set 
= double_speed
;
    if (double_speed_is_set
)
    {
        BIT__SET
(UCSR0A
, U2X0
);
    }
    else
    {
        BIT__RST
(UCSR0A
, U2X0
);
    }
}
/**************************************************************************//**
 * \fn void usart0__enable_receiver(void)
 *
 * \brief Enable USART 0 receiver.
 ******************************************************************************/
void
usart0__enable_receiver
(
    void
){
    BIT__SET
(UCSR0B
, RXEN0
);
}
/**************************************************************************//**
 * \fn void usart0__disable_receiver(void)
 *
 * \brief Disable USART 0 receiver.
 ******************************************************************************/
void
usart0__disable_receiver
(
    void
){
    BIT__RST
(UCSR0B
, RXEN0
);
}
/**************************************************************************//**
 * \fn void usart0__enable_transmitter(void)
 *
 * \brief Enable USART 0 transmitter.
 ******************************************************************************/
void
usart0__enable_transmitter
(
    void
){
    BIT__SET
(UCSR0B
, TXEN0
);
}
/**************************************************************************//**
 * \fn void usart0__disable_transmitter(void)
 *
 * \brief Disable USART 0 transmitter.
 ******************************************************************************/
void
usart0__disable_transmitter
(
    void
){
    BIT__RST
(UCSR0B
, TXEN0
);
}
/**************************************************************************//**
 * \fn uint8_t usart0__receive_byte(void)
 *
 * \brief Receive a byte on USART0.
 *
 * \return received byte
 ******************************************************************************/
uint16_t
usart0__receive_byte
(
    void
){
    // Wait for data to be received.
    while (!(UCSR0A 
& (1 << RXC0
)));
    // Get received data.
    uint16_t received_byte 
= UDR0
;
    if (USART__DATA_SIZE__9_BITS 
== configuration.
data_size)
    {
        // If 9-bit data size, get 9th bit.
        uint8_t resh 
= UCSR0B
;
        resh 
= (resh 
>> 1) & 0x01;
        received_byte 
= (resh 
<< 8) | received_byte
;
    }
    // Return received data from buffer.
    return received_byte
;
}
/**************************************************************************//**
 * \fn usart0__transmit_byte(uint8_t byte_to_transmit)
 *
 * \brief Transmit a byte on USART0.
 *
 * \param byte_to_transmit byte to transmit
 ******************************************************************************/
void
usart0__transmit_byte
(
    uint16_t byte_to_transmit
){
    // Wait for empty transmit buffer.
    while (!(UCSR0A 
& (1 << UDRE0
)));
    if (USART__DATA_SIZE__9_BITS 
== configuration.
data_size)
    {
        // If 9-bit data size, copy 9th bit to TXB80.
        UCSR0B 
&= ~
(1 << TXB80
);
        if (byte_to_transmit 
& 0x0100)
        {
            UCSR0B 
|= (1 << TXB80
);
        }
    }
    // Put data into transmit buffer, sends the data.
    UDR0 
= byte_to_transmit
;
}
/**************************************************************************//**
 * \fn void usart0__flush(void)
 *
 * \brief Flush USART0 receiver buffer.
 ******************************************************************************/
void
usart0__flush
(
    void
){
    uint8_t dummy 
= 0;
    while (UCSR0A 
& (1 << RXC0
))
    {
        dummy 
= UDR0
;
    }
}
/**************************************************************************//**
 * \fn void usart0__enable_rx_complete_interrupt(void)
 *
 * \brief Enable USART 0 receive complete interrupt.
 ******************************************************************************/
void
usart0__enable_rx_complete_interrupt
(
    void
){
    BIT__SET
(UCSR0B
, RXCIE0
);
    sei
();
}
/**************************************************************************//**
 * \fn void usart0__disable_rx_complete_interrupt(void)
 *
 * \brief Disable USART 0 receive complete interrupt.
 ******************************************************************************/
void
usart0__disable_rx_complete_interrupt
(
    void
){
    BIT__RST
(UCSR0B
, RXCIE0
);
    sei
();
}
/**************************************************************************//**
 * \fn void usart0__set_rx_complete_callback(
 * const usart__rx_complete_callback_t* p_callback)
 *
 * \brief Set a callback to call when receive byte complete interrupt is generated.
 *
 * \param[in]   p_callback  Callback to set.
 ******************************************************************************/
void
usart0__set_rx_complete_callback
(
    const usart__rx_complete_callback_t
*  p_callback
){
    // Check the preconditions.
    assert(NULL 
!= p_callback
);
    p_rx_complete 
= p_callback
;
}
/**************************************************************************//**
 *
 ******************************************************************************/
void
usart0__enable_tx_complete_interrupt
(
    void
){
    BIT__SET
(UCSR0B
, TXCIE0
);
    sei
();
}
/**************************************************************************//**
 *
 ******************************************************************************/
void
usart0__disable_tx_complete_interrupt
(
    void
){
    BIT__RST
(UCSR0B
, TXCIE0
);
    sei
();
}
/**************************************************************************//**
 *
 ******************************************************************************/
void
usart0__set_tx_complete_callback
(
    const usart__tx_complete_callback_t
*  p_callback
){
    // Check the preconditions.
    assert(NULL 
!= p_callback
);
    p_tx_complete 
= p_callback
;
}
/**************************************************************************//**
 *
 ******************************************************************************/
void
usart0__enable_data_register_empty_interrupt
(
    void
){
    BIT__SET
(UCSR0B
, UDRIE0
);
    sei
();
}
/**************************************************************************//**
 *
 ******************************************************************************/
void
usart0__disable_data_register_empty_interrupt
(
    void
){
    BIT__RST
(UCSR0B
, UDRIE0
);
    sei
();
}
/**************************************************************************//**
 *
 ******************************************************************************/
void
usart0__set_data_register_empty_callback
(
    const usart__data_register_empty_callback_t
*  p_callback
){
    // Check the preconditions.
    assert(NULL 
!= p_callback
);
    p_data_register_empty 
= p_callback
;
}
/******************************************************************************
 * Private function definitions.
 ******************************************************************************/
/**************************************************************************//**
 * \fn static uint16_t usart0__compute_ubrr(void)
 *
 * \brief Compute ubrr value.
 *
 * \return ubrr value.
 ******************************************************************************/
static inline
uint16_t
usart0__compute_ubrr
(
    void
){
    uint16_t ubrr 
= 0;
    switch (configuration.
mode)
    {
        case USART__MODE__ASYNCHRONOUS
:
        {
            if (!double_speed_is_set
)
            {
                ubrr 
= F_CPU 
/ (16 * usart__baudrate_values
[configuration.
baudrate]) - 1;
            }
            else
            {
                ubrr 
= F_CPU 
/ (8 * usart__baudrate_values
[configuration.
baudrate]) - 1;
            }
        }
        break;
        case USART__MODE__SYNCHRONOUS
:
        {
            ubrr 
= F_CPU 
/ (2 * usart__baudrate_values
[configuration.
baudrate]) - 1;
        }
        break;
        case USART__MODE__MASTER_SPI
:
        break;
        default:
        break;
    }
    return ubrr
;
}
/******************************************************************************
 * Interrupt vectors.
 ******************************************************************************/
/**************************************************************************//**
 * \fn ISR(USART_RX_vect)
 ******************************************************************************/
ISR
(USART0_RX_vect
)
{
    if (NULL 
!= p_rx_complete
)
    {
        p_rx_complete
();
    }
}
/**************************************************************************//**
 * \fn ISR(USART_TX_vect)
 ******************************************************************************/
ISR
(USART0_TX_vect
)
{
    if (NULL 
!= p_tx_complete
)
    {
        p_tx_complete
();
    }
}
/**************************************************************************//**
 * \fn ISR(USART_UDRE_vect)
 ******************************************************************************/
ISR
(USART0_UDRE_vect
)
{
    if (NULL 
!= p_data_register_empty
)
    {
        p_data_register_empty
();
    }
}