aversive_10-03-12/modules/comm/uart/uart_getconf.c

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/*  
 *  Copyright Droids Corporation, Microb Technology, Eirbot (2005)
 * 
 *  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 2 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
 *
 *  Revision : $Id: uart_getconf.c,v 1.2 2009-03-15 21:51:18 zer0 Exp $
 *
 */

/* Olivier MATZ, Droids-corp 2004 - 2007 */

#include <uart.h>
#include <uart_defs.h>
#include <uart_private.h>

#if UART_IS_USART

static inline uint8_t get_ucsrc(uint8_t num)
{
#ifdef URSEL
        uint8_t tmp;
        /* on some uC, reading UCSRxC is a bit tricky */
        switch(num) {
#ifdef UART0_COMPILE
                case 0:
                        tmp = UBRR0H;
                        tmp = UCSR0C;
                        break;
#endif
#ifdef UART1_COMPILE
                case 1:
                        tmp = UBRR1H;
                        tmp = UCSR1C;
                        break;
#endif
#ifdef UART2_COMPILE
                case 2:
                        tmp = UBRR2H;
                        tmp = UCSR2C;
                        break;
#endif
#ifdef UART3_COMPILE
                case 3:
                        tmp = UBRR3H;
                        tmp = UCSR3C;
                        break;
#endif
                default:
                        tmp = 0;
                        break;
        }
        return tmp;
#else
        return *uart_regs[num].ucsrc;
#endif /* URSEL */
}

/* return number of bits in current conf. Intr must be disabled. */
uint8_t uart_getconf_nbits(uint8_t num)
{
        uint8_t nbits;

        nbits = (get_ucsrc(num) >> UCSZ0) & 0x03;
#ifdef CONFIG_MODULE_UART_9BITS
        if (*uart_regs[num].ucsrb & (1 << UCSZ2))
                nbits += 4;
#endif
        nbits += 5;
        return nbits;
}

#else /* UART_IS_USART */

/* return number of bits in current conf */
uint8_t uart_getconf_nbits(uint8_t num)
{
#ifdef CONFIG_MODULE_UART_9BITS
        if (*uart_regs[num].ucsrb & (uint8_t)(1 << CHR9))
                return 8;
        else
                return 9;
#else
        return 8;
#endif
}

#endif /* UART_IS_USART */


#if UART_IS_USART

/* return number of bits in current conf */
static inline uint16_t uart_get_baudreg(uint8_t num)
{
        return ((uint16_t)*uart_regs[num].ubrrh << 8) | 
                (uint16_t)*uart_regs[num].ubrrl;
}

#else /* UART_IS_USART */

/* return number of bits in current conf */
static inline uint16_t uart_get_baudreg(uint8_t num)
{
        return (uint16_t)*uart_regs[num].ubrrl;
}

#endif /* UART_IS_USART */


/* get the running uart configurtion */
void uart_getconf(uint8_t num, struct uart_config *u)
{
        uint8_t tmp;
        uint8_t flags;

        IRQ_LOCK(flags);

        /* XXX */
        /* enabled if RXEN is set */
        if (*uart_regs[num].ucsrb & (1 << RXEN))
                u->enabled = 1;
        else
                u->enabled = 0;

        /* intrp enabled if RXCIE is set */
        if (*uart_regs[num].ucsrb & (1 << RXCIE))
                u->intr_enabled = 1;
        else
                u->intr_enabled = 0;

        /* use double speed */
        if (UART_HAS_U2X && (*uart_regs[num].ucsra & (1 << U2X)))
                u->use_double_speed = 1;
        else
                u->use_double_speed = 0;


        /* parity */
        if (UART_IS_USART) {
                tmp = get_ucsrc(num) & ((1 << UPM1) | (1 << UPM0));
                if (tmp == ((1 << UPM1) | (1 << UPM0)))
                        u->parity = UART_PARTITY_ODD;
                else if (tmp == (1 << UPM1))
                        u->parity = UART_PARTITY_EVEN;
                else
                        u->parity = UART_PARTITY_NONE;
        }
        else {
                u->parity = UART_PARTITY_NONE;
        }

        /* stop_bits */
        if  (UART_IS_USART && (get_ucsrc(num) & (1 << USBS))) {
                u->stop_bits = UART_STOP_BITS_2;
        }
        else {
                u->stop_bits = UART_STOP_BITS_1;
        }

        /* nbits */
        u->nbits = uart_getconf_nbits(num);
        u->baudrate = (F_CPU / ((uart_get_baudreg(num)+1) * 16)) ;

        IRQ_UNLOCK(flags);
}

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