spidigio.c

avr上的RTOS

/*
 * 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 EGNITE SOFTWARE GMBH 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 EGNITE
 * SOFTWARE GMBH 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/
 *
 */

/*
 * $Log: spidigio.c,v $
 * Revision 1.1  2005/07/26 18:02:40  haraldkipp
 * Moved from dev.
 *
 * Revision 1.5  2005/02/02 19:59:12  haraldkipp
 * Typo corrected. Compiler failed, if ports were not configured. Due
 * to the completely broken port configuration this error wasn't
 * detected.
 *
 * Revision 1.4  2005/01/22 19:25:14  haraldkipp
 * Changed AVR port configuration names from PORTx to AVRPORTx.
 *
 * Revision 1.3  2004/09/22 08:14:48  haraldkipp
 * Made configurable
 *
 * Revision 1.2  2004/09/08 10:53:25  haraldkipp
 * os/timer.c
 *
 * Revision 1.1.1.1  2003/05/09 14:40:50  haraldkipp
 * Initial using 3.2.1
 *
 * Revision 1.4  2003/02/04 17:50:54  harald
 * Version 3 released
 *
 * Revision 1.3  2003/01/14 13:34:53  harald
 * *** empty log message ***
 *
 * Revision 1.2  2002/08/11 12:25:38  harald
 * ICC mods
 *
 * Revision 1.1  2002/08/02 14:25:09  harald
 * First check in
 *
 */

/*
 * This header file specifies the hardware port bits. You
 * need to change or replace it, if your hardware differs.
 */
#include <cfg/arch/avr.h>

/*
 * The following header file contains the prototypes of
 * all global functions, which this module provides.
 */
#include <dev/spidigio.h>

/*
 * Determine ports, which had not been explicitly configured.
 */
#ifndef SPIDIGIO_SOUT_BIT
#define SPIDIGIO_SOUT_BIT 5
#define SPIDIGIO_SOUT_AVRPORT AVRPORTD
#define SPIDIGIO_SIN_BIT 6
#define SPIDIGIO_SIN_AVRPORT AVRPORTD
#define SPIDIGIO_SCLK_BIT 7
#define SPIDIGIO_SCLK_AVRPORT AVRPORTD
#define SPIDIGIO_LDI_BIT 7
#define SPIDIGIO_LDI_AVRPORT AVRPORTB
#define SPIDIGIO_LDO_BIT 5
#define SPIDIGIO_LDO_AVRPORT AVRPORTB
#endif

#if (SPIDIGIO_SOUT_AVRPORT == AVRPORTB)
#define SPIDIGIO_SOUT_PORT  PORTB
#define SPIDIGIO_SOUT_DDR   DDRB

#elif (SPIDIGIO_SOUT_AVRPORT == AVRPORTD)
#define SPIDIGIO_SOUT_PORT  PORTD
#define SPIDIGIO_SOUT_DDR   DDRD

#elif (SPIDIGIO_SOUT_AVRPORT == AVRPORTE)
#define SPIDIGIO_SOUT_PORT  PORTE
#define SPIDIGIO_SOUT_DDR   DDRE

#elif (SPIDIGIO_SOUT_AVRPORT == AVRPORTF)
#define SPIDIGIO_SOUT_PORT  PORTF
#define SPIDIGIO_SOUT_DDR   DDRF

#endif

#if (SPIDIGIO_SIN_AVRPORT == AVRPORTB)
#define SPIDIGIO_SIN_PORT   PORTB
#define SPIDIGIO_SIN_PIN    PINB
#define SPIDIGIO_SIN_DDR    DDRB

#elif (SPIDIGIO_SIN_AVRPORT == AVRPORTD)
#define SPIDIGIO_SIN_PORT   PORTD
#define SPIDIGIO_SIN_PIN    PIND
#define SPIDIGIO_SIN_DDR    DDRD

#elif (SPIDIGIO_SIN_AVRPORT == AVRPORTE)
#define SPIDIGIO_SIN_PORT   PORTE
#define SPIDIGIO_SIN_PIN    PINE
#define SPIDIGIO_SIN_DDR    DDRE

#elif (SPIDIGIO_SIN_AVRPORT == AVRPORTF)
#define SPIDIGIO_SIN_PORT   PORTF
#define SPIDIGIO_SIN_PIN    PINF
#define SPIDIGIO_SIN_DDR    DDRF
#endif

#if (SPIDIGIO_SCLK_AVRPORT == AVRPORTB)
#define SPIDIGIO_SCLK_PORT  PORTB
#define SPIDIGIO_SCLK_DDR   DDRB

#elif (SPIDIGIO_SCLK_AVRPORT == AVRPORTD)
#define SPIDIGIO_SCLK_PORT  PORTD
#define SPIDIGIO_SCLK_DDR   DDRD

#elif (SPIDIGIO_SCLK_AVRPORT == AVRPORTE)
#define SPIDIGIO_SCLK_PORT  PORTE
#define SPIDIGIO_SCLK_DDR   DDRE

#elif (SPIDIGIO_SCLK_AVRPORT == AVRPORTF)
#define SPIDIGIO_SCLK_PORT  PORTF
#define SPIDIGIO_SCLK_DDR   DDRF

#endif /* SPIDIGIO_SCLK_AVRPORT */

#if (SPIDIGIO_LDO_AVRPORT == AVRPORTB)
#define SPIDIGIO_LDO_PORT   PORTB
#define SPIDIGIO_LDO_DDR    DDRB

#elif (SPIDIGIO_LDO_AVRPORT == AVRPORTD)
#define SPIDIGIO_LDO_PORT   PORTD
#define SPIDIGIO_LDO_DDR    DDRD

#elif (SPIDIGIO_LDO_AVRPORT == AVRPORTE)
#define SPIDIGIO_LDO_PORT   PORTE
#define SPIDIGIO_LDO_DDR    DDRE

#elif (SPIDIGIO_LDO_AVRPORT == AVRPORTF)
#define SPIDIGIO_LDO_PORT   PORTF
#define SPIDIGIO_LDO_DDR    DDRF

#endif /* SPIDIGIO_LDO_AVRPORT */

#if (SPIDIGIO_LDI_AVRPORT == AVRPORTB)
#define SPIDIGIO_LDI_PORT   PORTB
#define SPIDIGIO_LDI_DDR    DDRB

#elif (SPIDIGIO_LDI_AVRPORT == AVRPORTD)
#define SPIDIGIO_LDI_PORT   PORTD
#define SPIDIGIO_LDI_DDR    DDRD

#elif (SPIDIGIO_LDI_AVRPORT == AVRPORTE)
#define SPIDIGIO_LDI_PORT   PORTE
#define SPIDIGIO_LDI_DDR    DDRE

#elif (SPIDIGIO_LDI_AVRPORT == AVRPORTF)
#define SPIDIGIO_LDI_PORT   PORTF
#define SPIDIGIO_LDI_DDR    DDRF

#endif /* SPIDIGIO_LDI_AVRPORT */

/*!
 * \addtogroup xgSpiDigIo
 */
/*@{*/

static ureg_t us_loops = 1;

/*!
 * \brief Loop for a small number of microseconds.
 *
 * This call will not release the CPU and will not switch to another 
 * thread. It simply executes a number of NOP (no operation) assembly 
 * statements.
 *
 * The routine is quite limited. Depending on the value of the
 * global variable us_loop, which is calculated in SpiDigitalInit(),
 * and based on the CPU clock. On a 14 MHz standard Ethernut its
 * value is 3, allowing a maximum delay of 85 microseconds.
 *
 * \param us Approximate delay in microseconds.
 *
 */
static INLINE void delay_us(ureg_t us)
{
    ureg_t _cnt = us * us_loops;

    while (_cnt--) {
        /*
         * A no-operation assembly statement is used here.
         * Without this statement, the compiler may completely
         * wipe out the loop during optimization.
         */
        _NOP();
    }
}

/*!
 * \brief Toggle shift register clock to perform a shift.
 *
 * Shifting is done on the falling edge of the clock line.
 *
 * The required puls width is 150 ns for the UCN5841 output and only 
 * 25 ns for the SN74HC165 input shift register hardware. However, 
 * longer cables and additional noise filters may increase the required 
 * minimum pulse length. On the reference hardware the rising edge of 
 * the RC filters used is about 3 microseconds.
 */
static INLINE void ShiftDigital(void)
{
    /* Switch clock line low. */
    cbi(SPIDIGIO_SCLK_PORT, SPIDIGIO_SCLK_BIT);
    /* Four microseconds delay. */
    delay_us(4);

    /* Switch clock line back high. */
    sbi(SPIDIGIO_SCLK_PORT, SPIDIGIO_SCLK_BIT);
    /* Four microseconds delay. */
    delay_us(4);
}

/*!
 * \brief Query digital inputs.
 *
 * SpiDigitalInit() must have been called by the application before 
 * calling this function.
 *
 * This routine does not check the validity of the parameter.
 *
 * \param num Number of bits to query, typically 8, 16, 24 or the maximum 
 *            value of 32. This number should exactly match the number of
 *            input pins. If it is lower, only the most significant bits
 *            are returned. However, this may be used by an application
 *            to scan these bits more often with reduced overhead.
 *
 * \return Binary value of the requested inputs. Only the specified number 
 *         of bits are used. Bit 0 is the one, which has been shifted out
 *         last.
 */
u_long SpiDigitalGet(ureg_t num)
{