/*
 * Copyright (C) 2012-2013 by egnite GmbH
 * Copyright (C) 2001-2003 by egnite Software GmbH
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * For additional information see http://www.ethernut.de/
 */

/*!
 * \file arch/avr/usart1cb_avr.c
 * \brief Low level routines for UART1 on AVR.
 *
 * Contains those functions, which are implemented individually for UART1.
 *
 * See comments in the UART0 driver about constant port addresses. At
 * least for the ATmega128, bit operations are limited to some UART0
 * registers only. So, for those applications requiring multiple UARTs,
 * it may be OK to make this code working for UART2 and above.
 *
 * \verbatim
 * $Id$
 * \endverbatim
 */

#include <cfg/arch/avr.h>
#include <stdint.h>

#include <dev/irqreg.h>
#include <dev/usart.h>
#include <sys/timer.h>
#include <sys/atom.h>

#include <arch/avr/usart_avrctl.h>
#include <arch/avr/usart_cb_avr.h>

#ifndef UART1_INIT_BAUDRATE
#define UART1_INIT_BAUDRATE 115200
#endif

/*!
 * \name UART1 CTS Handshake Sense
 *
 * UART1_CTS_IRQ must be defined to enable CTS sensing.
 */
#ifdef UART1_CTS_IRQ
#undef UART_CTS_IRQ
#define UART_CTS_IRQ    UART1_CTS_IRQ
#include <arch/avr/usart_avrcts.h>
#endif

/*!
 * \name UART1 RTS Handshake Control
 *
 * UART1_RTS_BIT and UART1_RTS_PORT must be defined to enable RTS control.
 */
#if defined(UART1_RTS_BIT) && defined(UART1_RTS_AVRPORT)

#if (UART1_RTS_AVRPORT == AVRPORTB)
#define UART1_RTS_PORT  PORTB
#define UART1_RTS_DDR   DDRB

#elif (UART1_RTS_AVRPORT == AVRPORTD)
#define UART1_RTS_PORT  PORTD
#define UART1_RTS_DDR   DDRD

#elif (UART1_RTS_AVRPORT == AVRPORTE)
#define UART1_RTS_PORT  PORTE
#define UART1_RTS_DDR   DDRE

#elif (UART1_RTS_AVRPORT == AVRPORTF)
#define UART1_RTS_PORT  PORTF
#define UART1_RTS_DDR   DDRF

#elif (UART1_RTS_AVRPORT == AVRPORTG)
#define UART1_RTS_PORT  PORTG
#define UART1_RTS_DDR   DDRG

#elif (UART1_RTS_AVRPORT == AVRPORTH)
#define UART1_RTS_PORT  PORTH
#define UART1_RTS_DDR   DDRH
#endif

#endif

static AVRUSART_IFC ifc_usart1 = { 1, 0 };

static void AvrUsart1RxData(void *arg)
{
    uint8_t ch;
    USARTCB_DCB *dcb;
    cb_size_t idx;
    USARTCB_RXBUFF *rxcb;
    uint8_t err;

    err = inb(UCSR1A) & (_BV(FE) | _BV(DOR) | _BV(UPE));
    ch = inb(UDR1);
    if (err == 0) {
        dcb = (USARTCB_DCB *) arg;
        rxcb = &dcb->usart_rx_buff;
        idx = (rxcb->rxb_wri + 1) & rxcb->rxb_siz;
        if (idx == rxcb->rxb_rdi) {
            /* Receive buffer overflow. */
            cbi(UCSR1B, RXCIE);
        } else {
            rxcb->rxb_buf[rxcb->rxb_wri] = ch;
            rxcb->rxb_wri = idx;
            if (rxcb->rxb_cnt++ == 0) {
                NutEventPostFromIrq(&rxcb->rxb_que);
            }
            /* If an RTS port has been defined and if RTS control has
               been enabled and if the number of bytes in the receive
               buffer reached the high watermark, then disable RTS to
               stop the remote transmitter. */
#if defined(UART1_RTS_PORT) && defined(UART1_RTS_BIT)
            if ((dcb->usart_mode & USART_MF_RTSCONTROL) != 0 && rxcb->rxb_cnt >= dcb->usart_rx_hiwm) {
                sbi(UART1_RTS_PORT, UART1_RTS_BIT);
            }
#endif
        }
    } else {
        ifc_usart1.uifc_errors |= err;
    }
}

#ifdef UART_CTS_BIT
/*!
 * \brief USART1 CTS sense interrupt handler.
 *
 * This interrupt routine is called when the CTS line level is low.
 * Typical line drivers negate the signal, thus driving our port
 * low when CTS is active.
 *
 * This routine exists only if the hardware configuration defines a
 * port bit to sense the CTS signal.
 */
static void AvrUsart1CtsActive(void *arg)
{
    /* Enable transmit interrupt. */
    sbi(UCSR1B, UDRIE);
    /* Disable CTS sense interrupt. */
    cbi(EIMSK, UART_CTS_BIT);
}
#endif

static void AvrUsart1TxData(void *arg)
{
    USARTCB_DCB *dcb = (USARTCB_DCB *) arg;
    USARTCB_TXBUFF *txcb = &dcb->usart_tx_buff;
    cb_size_t idx;

    idx = txcb->txb_rdi;
    if (idx == txcb->txb_wri) {
        /* Transmit buffer underrun. */
        cbi(UCSR1B, UDRIE);
        NutEventPostFromIrq(&txcb->txb_que);
    } else {
#if defined(UART_CTS_BIT) && defined(UART_CTS_PIN)
        /* If CTS has been disabled, we disable the transmit interrupts
           and return without sending anything. */
        if ((dcb->usart_mode & USART_MF_CTSSENSE) != 0 && bit_is_set(UART_CTS_PIN, UART_CTS_BIT)) {
            cbi(UCSR1B, UDRIE);
            sbi(EIMSK, UART_CTS_BIT);
            return;
        }
#endif
        outb(UDR1, txcb->txb_buf[idx]);
        txcb->txb_rdi = (idx + 1) & txcb->txb_siz;
        if (txcb->txb_cnt-- == txcb->txb_siz) {
            NutEventPostFromIrq(&txcb->txb_que);
        }
    }
}

/*!
 * \brief Enable AVR USART1.
 */
static int AvrUsart1Enable(USARTCB_DCB *dcb)
{
    if (NutRegisterIrqHandler(&sig_UART1_RECV, AvrUsart1RxData, dcb)) {
        return -1;
    }
    if (NutRegisterIrqHandler(&sig_UART1_DATA, AvrUsart1TxData, dcb)) {
        return -1;
    }

#if defined(UART_CTS_BIT)
#if defined(UART_CTS_PORT)
    sbi(UART_CTS_PORT, UART_CTS_BIT);
#endif
#if defined(UART_CTS_DDR)
    cbi(UART_CTS_DDR, UART_CTS_BIT);
#endif
#endif
#if defined(UART_CTS_SIGNAL)
    NutRegisterIrqHandler(&UART_CTS_SIGNAL, AvrUsart1CtsActive, 0);
    NutIrqSetMode(&UART_CTS_SIGNAL, NUT_IRQMODE_FALLINGEDGE);
#endif

#if UART1_INIT_BAUDRATE
    {
        uint32_t baud = UART1_INIT_BAUDRATE;
        AvrUsartControl(dcb, UART_SETSPEED, &baud);
    }
#endif
    sbi(UCSR1B, TXEN);
    sbi(UCSR1B, RXEN);

#if defined(UART1_RTS_DDR) && defined(UART1_RTS_BIT)
    sbi(UART1_RTS_DDR, UART1_RTS_BIT);
#endif

    return 0;
}

static int AvrUsart1Disable(USARTCB_DCB *dcb)
{
    return -1;
}

static void AvrUsart1TxStart(USARTCB_DCB *dcb)
{
    USARTCB_TXBUFF *txcb = &dcb->usart_tx_buff;
    cb_size_t idx;

#if defined(UART_CTS_BIT) && defined(UART_CTS_PIN)
    if ((dcb->usart_mode & USART_MF_CTSSENSE) != 0 && bit_is_set(UART_CTS_PIN, UART_CTS_BIT)) {
        sbi(EIMSK, UART_CTS_BIT);
        return;
    }
#endif
    if ((inb(UCSR1A) & _BV(TXC1)) == 0 && (inb(UCSR1A) & _BV(UDRE1)) != 0) {
        idx = txcb->txb_rdi;
        if (idx != txcb->txb_wri) {
            txcb->txb_rdi = (idx + 1) & txcb->txb_siz;
            outb(UDR1, txcb->txb_buf[idx]);
        }
    }
    sbi(UCSR1B, UDRIE);
}

static void AvrUsart1TxStop(USARTCB_DCB *dcb)
{
    /* Disable receive and transmit interrupts. */
    cbi(UCSR1B, TXCIE);
    cbi(UCSR1B, UDRIE);
}

static void AvrUsart1RxStart(USARTCB_DCB *dcb)
{
    sbi(UCSR1B, RXCIE);
#if defined(UART1_RTS_PORT) && defined(UART1_RTS_BIT)
    if (dcb->usart_rx_buff.rxb_cnt < dcb->usart_rx_hiwm) {
        /* Enable handshake. */
        cbi(UART1_RTS_PORT, UART1_RTS_BIT);
    }
#endif
}

static void AvrUsart1RxStop(USARTCB_DCB *dcb)
{
    /* Disable receive and transmit interrupts. */
    cbi(UCSR1B, RXCIE);
}

/*!
 * \brief Set and query the UART status.
 */
static uint32_t AvrUsart1Status(USARTCB_DCB *dcb, uint32_t stat)
{
    uint32_t rc = 0;

    /*
     * Set receiver error flags.
     */
    if (ifc_usart1.uifc_errors & _BV(FE1)) {
        rc |= UART_FRAMINGERROR;
    }
    if (ifc_usart1.uifc_errors & _BV(DOR1)) {
        rc |= UART_OVERRUNERROR;
    }
    if (ifc_usart1.uifc_errors & _BV(UPE1)) {
        rc |= UART_PARITYERROR;
    }
    ifc_usart1.uifc_errors = 0;

    return rc;
}

static USARTCB_DCB dcb_usart1 = {
    (uintptr_t) &ifc_usart1,/* usart_hwif. */
    AvrUsart1Enable,        /* usart_enable(). */
    AvrUsart1Disable,       /* usart_disable(). */
    AvrUsartControl,        /* usart_control(). */
    0,                      /* usart_mode. */
#if defined(UART1_RTS_BIT)
    USART_MF_RTSCONTROL |
#endif
#if defined(UART_CTS_BIT)
    USART_MF_CTSSENSE |
#endif
    USART_MF_COOKEDMODE,    /* usart_caps. */
    AvrUsart1Status,        /* usart_status(). */
    { NULL, 0, 0, 0, NULL, 0 }, /* usart_tx_buff. */
    0,                      /* usart_wr_tmo. */
    AvrUsart1TxStart,       /* usart_tx_start(). */
    AvrUsart1TxStop,        /* usart_tx_stop(). */
    { NULL, 0, 0, 0, NULL, 0 }, /* usart_rx_buff. */
    0,                      /* usart_rd_tmo. */
    0,                      /* usart_rx_cr. */
    0,                      /* usart_rx_lowm. */
    0,                      /* usart_rx_hiwm. */
    AvrUsart1RxStart,       /* usart_rx_start(). */
    AvrUsart1RxStop         /* usart_rx_stop(). */
};

NUTDEVICE devUsart1CbAvr = {
    NULL,           /* Pointer to next device, dev_next. */
    {'u', 'a', 'r', 't', '1', 0, 0, 0, 0}, /* Hardware device name, dev_name. */
    IFTYP_CHAR,     /* Type of device, dev_type. */
    0,              /* Base address, dev_base (not used). */
    0,              /* First interrupt number, dev_irq (not used). */
    NULL,           /* Interface control block, dev_icb (not used). */
    &dcb_usart1,    /* Driver control block, dev_dcb. */
    UsartCbInit,    /* Driver initialization routine, dev_init. */
    UsartCbIoCtrl,  /* Driver specific control function, dev_ioctl. */
    UsartCbRead,    /* Read from device, dev_read. */
    UsartCbWrite,   /* Write to device, dev_write. */
    UsartCbWrite_P, /* Write to device, dev_write_P. */
    UsartCbOpen,    /* Open a device or file, dev_open. */
    UsartCbClose,   /* Close a device or file, dev_close. */
    UsartCbSize,    /* Request file size, dev_size. */
    0,              /* Select function, optional, not yet implemented */
};