sama5d4.git - Gitblit

parent: 912f9e0e | patch | commit | ignore whitespace

guowenxue

2019-08-27 03ada50f4e3993fc9e3d4c17e952f12bb67d7d98

add AT91 GPIO AND spi library

5 files added

	program/lylib/at91_sysGpio.c	210 ●●●●● patch \| view \| raw \| blame \| history
	program/lylib/at91_sysGpio.h	62 ●●●●● patch \| view \| raw \| blame \| history
	program/lylib/at91_sysGpioDef.h	221 ●●●●● patch \| view \| raw \| blame \| history
	program/lylib/spidev.c	255 ●●●●● patch \| view \| raw \| blame \| history
	program/lylib/spidev.h	75 ●●●●● patch \| view \| raw \| blame \| history

 program/lylib/at91_sysGpio.c

New file
@@ -0,0 +1,210 @@
/*********************************************************************************
 *      Copyright:  (C) 2019 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  at91_sysGpio.c
 *    Description:  This file si GPIO API operatore on /sys/class/gpio/xxx
 *                 
 *        Version:  1.0.0(2019年08月26日)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "2019年08月26日 22时28分19秒"
 *                 
 ********************************************************************************/

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>

#include "at91_sysGpio.h"


/*  export $port in /sys/class/gpio/export */
int gpio_export(const char *port)
{
    char          fpath[SYSFILE_LEN];
    FILE          *fp;
    int           pin;

    if(!port)
    {
        gpio_print("invalid input arguments\n");
        return -1;
    }

    snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

    /* GPIO port already export */
    if( !access(fpath, F_OK) )
    {
        gpio_print("%s already export\n", port);
        return 0;
    }
    
    if( !(fp=fopen(SYSGPIO_EXPORT_PATH, "w")) )
    {
        gpio_print("open '%s' failure: %s\n", SYSGPIO_EXPORT_PATH, strerror(errno));
        return -2;
    }

    pin = at91_port2pin(port);
    fprintf(fp, "%d", pin);

    fclose(fp);

    return 0;
}


/*  unexport $port in /sys/class/gpio/unexport */
int gpio_unexport(const char *port)
{
    char          fpath[SYSFILE_LEN];
    FILE          *fp;
    int           pin;

    if(!port)
    {
        gpio_print("invalid input arguments\n");
        return -1;
    }

    snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

    /* GPIO port not export */
    if( access(fpath, F_OK) )
    {
        gpio_print("%s not export\n", port);
        return 0;
    }
    
    if( !(fp=fopen(SYSGPIO_UNEXPORT_PATH, "w")) )
    {
        gpio_print("open '%s' failure: %s\n", SYSGPIO_EXPORT_PATH, strerror(errno));
        return -2;
    }

    pin = at91_port2pin(port);
    fprintf(fp, "%d", pin);

    fclose(fp);

    return 0;
}


/*  configure $port direction as $mode */
int gpio_config(const char *port, const char *mode)
{
    char          fpath[SYSFILE_LEN];
    FILE          *fp;
    int           size;

    if(!port)
    {
        gpio_print("invalid input arguments\n");
        return 0;
    }

    snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

    if( access(fpath, F_OK) ) /* GPIO port not export */
    {
        if( gpio_export(port) < 0 )
            return -1;
    }
    
    size = SYSFILE_LEN-strlen(fpath);
    strncat(fpath, "/direction", size);
    if( !(fp=fopen(fpath, "w")) )
    {
        gpio_print("open '%s' failure: %s\n", fpath, strerror(errno));
        return -1;
    }

    fputs(mode, fp);

    fclose(fp);

    return 0;
}



/*  write $value into GPIO $port */
int gpio_write(const char *port, const char *value)
{
    char          fpath[SYSFILE_LEN];
    FILE          *fp;
    int           size;

    if(!port)
    {
        gpio_print("invalid input arguments\n");
        return 0;
    }

    snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

    if( access(fpath, F_OK) ) /* GPIO port not export */
    {
        if( gpio_export(port) < 0 )
            return -1;
    }
    
    size = SYSFILE_LEN-strlen(fpath);
    strncat(fpath, "/value", size);
    if( !(fp=fopen(fpath, "w")) )
    {
        gpio_print("open '%s' failure: %s\n", fpath, strerror(errno));
        return -1;
    }

    fputs(value, fp);

    fclose(fp);

    return 0;
}


/*  read gpio value from $port  */
int gpio_read(const char *port)
{
    char          fpath[SYSFILE_LEN];
    FILE          *fp;
    int           size;
    char          v_str[32];

    if(!port)
    {
        gpio_print("invalid input arguments\n");
        return 0;
    }

    snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

    if( access(fpath, F_OK) ) /* GPIO port not export */
    {
        return -1;
    }
    
    size = SYSFILE_LEN-strlen(fpath);
    strncat(fpath, "/value", size);
    if( !(fp=fopen(fpath, "r")) )
    {
        gpio_print("open '%s' failure: %s\n", fpath, strerror(errno));
        return -1;
    }

    memset(v_str, 0, sizeof(v_str));
    fgets(v_str, sizeof(v_str), fp);

    fclose(fp);

    return atoi(v_str);
}


 program/lylib/at91_sysGpio.h

New file
@@ -0,0 +1,62 @@
/*********************************************************************************
 *      Copyright:  (C) 2019 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  at91_sysGpio.h
 *    Description:  This file si GPIO API operatore on /sys/class/gpio/xxx
 *                 
 *        Version:  1.0.0(2019年08月26日)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "2019年08月26日 22时28分19秒"
 *                 
 ********************************************************************************/

#ifndef  _AT91_SYSGPIO_H_
#define  _AT91_SYSGPIO_H_

#include "at91_sysGpioDef.h"

#define SYSFILE_LEN                        64

#define SYSGPIO_PATH                       "/sys/class/gpio/"

#define SYSGPIO_EXPORT_PATH                SYSGPIO_PATH"export" 
#define SYSGPIO_UNEXPORT_PATH              SYSGPIO_PATH"unexport" 

//#define GPIO_DEBUG_PRINT

#ifdef  GPIO_DEBUG_PRINT
#define gpio_print(format,args...) printf(format, ##args)
#else
#define gpio_print(format,args...) do{} while(0);
#endif


/* export $port in /sys/class/gpio/export  */
extern int gpio_export(const char *port);


/* unexport $port in /sys/class/gpio/unexport  */
extern int gpio_unexport(const char *port);


#define  M_IN                   "in"     /* set GPIO as input mode */
#define  M_OUT                  "out"    /* set GPIO as output mode */
#define  M_HIGH                 "high"   /* set GPIO as output mode and value be high<1> */
#define  M_LOW                  "low"    /* set GPIO as output mode and value be low<0>  */
/* configure $port direction as $mode */
extern int gpio_config(const char *port, const char *mode);


#define V_HIGH                  "1"
#define V_LOW                   "0"
/* write $value into GPIO $port   */
extern int gpio_write(const char *port, const char *value);


/* read gpio value from $port  */
extern int gpio_read(const char *port);

#endif   /* ----- #ifndef _AT91_SYSGPIO_H_  ----- */



 program/lylib/at91_sysGpioDef.h

New file
@@ -0,0 +1,221 @@
/********************************************************************************
 *      Copyright:  (C) 2019 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  at91_sysGpioDef.h
 *    Description:  This head file 
 *
 *        Version:  1.0.0(2019年08月26日)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "2019年08月26日 21时46分02秒"
 *                 
 ********************************************************************************/

#ifndef  _AT91_SYSGPIODEF_H_
#define  _AT91_SYSGPIODEF_H_

#include <ctype.h>
#include <stdlib.h>

#define PA(x)                 "pioA"#x
#define PB(x)                 "pioB"#x
#define PC(x)                 "pioC"#x
#define PD(x)                 "pioD"#x
#define PE(x)                 "pioE"#x

/*  SAMA5D44 devided all GPIOs into 5 groups(PA,PB,PC,PD,PE), and each group control 32 Pins
 *
 * This macro used convert PAx,PBx...,PEx to Pin number: 0~158
 * s should be: PA0-PA31, PB0-PB31, PC0-PC31, PD0-PD31, PE0-PE30(158)
 */
#define at91_port2pin(p)      ((tolower(p[3])-'a')*32 + atoi(p+4) )


/*+-----------------------------------------------------+
 *|  GPIO PortA:  PA0~PA31 defined as "pioA0"-"pioA31"  |
 *+-----------------------------------------------------+*/

#define PA0                   PA(0)
#define PA1                   PA(1)
#define PA2                   PA(2)
#define PA3                   PA(3)
#define PA4                   PA(4)
#define PA5                   PA(5)
#define PA6                   PA(6)
#define PA7                   PA(7)
#define PA8                   PA(8)
#define PA9                   PA(9)
#define PA10                  PA(10)
#define PA11                  PA(11)
#define PA12                  PA(12)
#define PA13                  PA(13)
#define PA14                  PA(14)
#define PA15                  PA(15)
#define PA16                  PA(16)
#define PA17                  PA(17)
#define PA18                  PA(18)
#define PA19                  PA(19)
#define PA20                  PA(20)
#define PA21                  PA(21)
#define PA22                  PA(22)
#define PA23                  PA(23)
#define PA24                  PA(24)
#define PA25                  PA(25)
#define PA26                  PA(26)
#define PA27                  PA(27)
#define PA28                  PA(28)
#define PA29                  PA(29)
#define PA30                  PA(30)
#define PA31                  PA(31)


/*+-----------------------------------------------------+
 *|  GPIO PortB:  PB0~PB31 defined as "pioB0"-"pioB31"  |
 *+-----------------------------------------------------+*/

#define PB0                   PB(0)
#define PB1                   PB(1)
#define PB2                   PB(2)
#define PB3                   PB(3)
#define PB4                   PB(4)
#define PB5                   PB(5)
#define PB6                   PB(6)
#define PB7                   PB(7)
#define PB8                   PB(8)
#define PB9                   PB(9)
#define PB10                  PB(10)
#define PB11                  PB(11)
#define PB12                  PB(12)
#define PB13                  PB(13)
#define PB14                  PB(14)
#define PB15                  PB(15)
#define PB16                  PB(16)
#define PB17                  PB(17)
#define PB18                  PB(18)
#define PB19                  PB(19)
#define PB20                  PB(20)
#define PB21                  PB(21)
#define PB22                  PB(22)
#define PB23                  PB(23)
#define PB24                  PB(24)
#define PB25                  PB(25)
#define PB26                  PB(26)
#define PB27                  PB(27)
#define PB28                  PB(28)
#define PB29                  PB(29)
#define PB30                  PB(30)
#define PB31                  PB(31)

/*+-----------------------------------------------------+
 *|  GPIO PortC:  PC0~PC31 defined as "pioC0"-"pioC31"  |
 *+-----------------------------------------------------+*/

#define PC0                   PC(0)
#define PC1                   PC(1)
#define PC2                   PC(2)
#define PC3                   PC(3)
#define PC4                   PC(4)
#define PC5                   PC(5)
#define PC6                   PC(6)
#define PC7                   PC(7)
#define PC8                   PC(8)
#define PC9                   PC(9)
#define PC10                  PC(10)
#define PC11                  PC(11)
#define PC12                  PC(12)
#define PC13                  PC(13)
#define PC14                  PC(14)
#define PC15                  PC(15)
#define PC16                  PC(16)
#define PC17                  PC(17)
#define PC18                  PC(18)
#define PC19                  PC(19)
#define PC20                  PC(20)
#define PC21                  PC(21)
#define PC22                  PC(22)
#define PC23                  PC(23)
#define PC24                  PC(24)
#define PC25                  PC(25)
#define PC26                  PC(26)
#define PC27                  PC(27)
#define PC28                  PC(28)
#define PC29                  PC(29)
#define PC30                  PC(30)
#define PC31                  PC(31)

/*+-----------------------------------------------------+
 *|  GPIO PortD:  PD0~PD31 defined as "pioD0"-"pioD31"  |
 *+-----------------------------------------------------+*/

#define PD0                   PD(0)
#define PD1                   PD(1)
#define PD2                   PD(2)
#define PD3                   PD(3)
#define PD4                   PD(4)
#define PD5                   PD(5)
#define PD6                   PD(6)
#define PD7                   PD(7)
#define PD8                   PD(8)
#define PD9                   PD(9)
#define PD10                  PD(10)
#define PD11                  PD(11)
#define PD12                  PD(12)
#define PD13                  PD(13)
#define PD14                  PD(14)
#define PD15                  PD(15)
#define PD16                  PD(16)
#define PD17                  PD(17)
#define PD18                  PD(18)
#define PD19                  PD(19)
#define PD20                  PD(20)
#define PD21                  PD(21)
#define PD22                  PD(22)
#define PD23                  PD(23)
#define PD24                  PD(24)
#define PD25                  PD(25)
#define PD26                  PD(26)
#define PD27                  PD(27)
#define PD28                  PD(28)
#define PD29                  PD(29)
#define PD30                  PD(30)
#define PD31                  PD(31)

/*+-----------------------------------------------------+
 *|  GPIO PortE:  PE0~PE30 defined as "pioE0"-"pioE30"  |
 *+-----------------------------------------------------+*/

#define PE0                   PE(0)
#define PE1                   PE(1)
#define PE2                   PE(2)
#define PE3                   PE(3)
#define PE4                   PE(4)
#define PE5                   PE(5)
#define PE6                   PE(6)
#define PE7                   PE(7)
#define PE8                   PE(8)
#define PE9                   PE(9)
#define PE10                  PE(10)
#define PE11                  PE(11)
#define PE12                  PE(12)
#define PE13                  PE(13)
#define PE14                  PE(14)
#define PE15                  PE(15)
#define PE16                  PE(16)
#define PE17                  PE(17)
#define PE18                  PE(18)
#define PE19                  PE(19)
#define PE20                  PE(20)
#define PE21                  PE(21)
#define PE22                  PE(22)
#define PE23                  PE(23)
#define PE24                  PE(24)
#define PE25                  PE(25)
#define PE26                  PE(26)
#define PE27                  PE(27)
#define PE28                  PE(28)
#define PE29                  PE(29)
#define PE30                  PE(30)


#endif   /* ----- #ifndef _AT91_SYSGPIODEF_H_  ----- */


 program/lylib/spidev.c

New file
@@ -0,0 +1,255 @@
/*********************************************************************************
 *      Copyright:  (C) 2019 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  spidev.c
 *    Description:  This file is spidev user space API.
 *                 
 *        Version:  1.0.0(2019年08月19日)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "2019年08月19日 23时18分54秒"
 *                 
 ********************************************************************************/
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include "spidev.h"

int spi_init(spidev_t *spi, char *spidev, uint8_t bpw, uint32_t speed, uint32_t delay, uint32_t mode)
{
    int            rv = 0;

    if( !spi || !spidev )
    {
        spi_dbg("Invalid input arguments\n");
        return -1;
    }

    memset(spi, 0, sizeof(*spi));

    strncpy(spi->devname, spidev, DEVNAME_LEN);
    spi->bits = bpw;
    spi->speed = speed*1000; /* speed unit is KHz */
    spi->delay = delay;
    spi->mode = mode;

    spi->fd = open(spidev, O_RDWR);
    if( spi->fd < 0)
    {
        spi_dbg("Open SPI device '%s' failure: %s\n", spidev, strerror(errno));
        rv = -2;
        goto cleanup;
    }

    /* set bits per word */
    if( ioctl(spi->fd, SPI_IOC_WR_BITS_PER_WORD, &bpw) < 0 )
    {
        spi_dbg("Set SPI '%s' bit per words to [%d] failure: %s\n", spidev, bpw, strerror(errno));
        rv = -3;
        goto cleanup;
    }

    /* set bits per word */
    if( ioctl(spi->fd, SPI_IOC_WR_MAX_SPEED_HZ, &spi->speed) < 0 )
    {
        spi_dbg("Set SPI '%s' speed to %dKHz failure: %s\n", spidev, speed, strerror(errno));
        rv = -4;
        goto cleanup;
    }

    /* set spi mode */
    if( ioctl(spi->fd, SPI_IOC_WR_MODE32, &mode) < 0 )
    {
        spi_dbg("Set SPI '%s' mode to [0x%0x] failure: %s\n", spidev, mode, strerror(errno));
        rv = -5;
        goto cleanup;
    }

cleanup:
    if( rv < 0 )
    {
        close(spi->fd);
    }

    return rv;
}

int spi_read(spidev_t *spi, char *buf, int size)
{
    int                rv = 0;
    void              *dummy_buf;

    struct spi_ioc_transfer tr = 
    {
        .rx_buf = (unsigned long)buf,
        .len = size,
        .delay_usecs = spi->delay,
        .speed_hz = spi->speed,
        .bits_per_word = spi->bits,
    };

    if( !spi || !buf || size<=0 )
    {
        spi_dbg("Invalid input arguments\n");
        return -1;
    }

    if( ! (dummy_buf=malloc(tr.len)) )
    {
        spi_dbg("spi_read malloc failure: %s\n", strerror(errno));
        return -2;
    }
    tr.tx_buf = (unsigned long)dummy_buf;

    if ( spi->mode & (SPI_TX_QUAD|SPI_RX_QUAD) ) 
        tr.tx_nbits = 4; 

    if ( spi->mode & (SPI_TX_DUAL|SPI_RX_DUAL) ) 
        tr.tx_nbits = 2; 

    if (!(spi->mode & SPI_LOOP)) 
    { 
        if (spi->mode & (SPI_TX_QUAD|SPI_TX_DUAL)) 
            tr.rx_buf = 0; 
        else if (spi->mode & (SPI_RX_QUAD|SPI_RX_DUAL))
            tr.tx_buf = 0; 
    } 

    if( ioctl(spi->fd, SPI_IOC_MESSAGE(1), &tr) < 0)
    {
        spi_dbg("spi_read SPI_IOC_MESSAGE failure: %s\n", strerror(errno)); 
        rv = -3;
        goto cleanup;
    }

cleanup:
    if( dummy_buf )
    {
        free( dummy_buf );
    }

    return rv;
}


int spi_write(spidev_t *spi, char *data, int nbytes)
{
    int                rv = 0;
    void              *dummy_buf;

    struct spi_ioc_transfer tr = 
    {
        .tx_buf = (unsigned long)data,
        .len = nbytes,
        .delay_usecs = spi->delay,
        .speed_hz = spi->speed,
        .bits_per_word = spi->bits,
    };


    if( !spi || !data || nbytes<= 0)
    {
        spi_dbg("Invalid input arguments\n");
        return -1;
    }

    if( ! (dummy_buf=malloc(tr.len)) )
    {
        spi_dbg("spi_read malloc failure: %s\n", strerror(errno));
        return -1;
    }
    tr.rx_buf = (unsigned long)dummy_buf;

    if ( spi->mode & (SPI_TX_QUAD|SPI_RX_QUAD) ) 
        tr.tx_nbits = 4; 

    if ( spi->mode & (SPI_TX_DUAL|SPI_RX_DUAL) ) 
        tr.tx_nbits = 2; 

    if (!(spi->mode & SPI_LOOP)) 
    { 
        if (spi->mode & (SPI_TX_QUAD|SPI_TX_DUAL)) 
            tr.rx_buf = 0; 
        else if (spi->mode & (SPI_RX_QUAD|SPI_RX_DUAL))
            tr.tx_buf = 0; 
    } 

    if( ioctl(spi->fd, SPI_IOC_MESSAGE(1), &tr) < 0)
    {
        spi_dbg("spi_read SPI_IOC_MESSAGE failure: %s\n", strerror(errno)); 
        rv = -2;
        goto cleanup;
    }

cleanup:
    if( dummy_buf )
    {
        free( dummy_buf );
    }

    return rv;
}

int spi_rdwr(spidev_t *spi, char *data,  char *rbuf, int nbytes)
{
    int                rv = 0;

    struct spi_ioc_transfer tr = 
    {
        .tx_buf = (unsigned long)data,
        .rx_buf = (unsigned long)rbuf,
        .len = nbytes,
        .delay_usecs = spi->delay,
        .speed_hz = spi->speed,
        .bits_per_word = spi->bits,
    };

    if( !spi || !data || nbytes<=0 )
    {
        spi_dbg("Invalid input arguments\n");
        return -1;
    }


    if ( spi->mode & (SPI_TX_QUAD|SPI_RX_QUAD) ) 
        tr.tx_nbits = 4; 

    if ( spi->mode & (SPI_TX_DUAL|SPI_RX_DUAL) ) 
        tr.tx_nbits = 2; 

    if (!(spi->mode & SPI_LOOP)) 
    { 
        if (spi->mode & (SPI_TX_QUAD|SPI_TX_DUAL)) 
            tr.rx_buf = 0; 
        else if (spi->mode & (SPI_RX_QUAD|SPI_RX_DUAL))
            tr.tx_buf = 0; 
    } 


    if( ioctl(spi->fd, SPI_IOC_MESSAGE(1), &tr) < 0)
    {
        spi_dbg("spi_read SPI_IOC_MESSAGE failure: %s\n", strerror(errno)); 
        rv = -3;
    }

    return rv;
}

int spi_term(spidev_t *spi)
{
    if( !spi )
    {
        spi_dbg("Invalid input arguments\n");
        return -1;
    }

    if(spi->fd)
    {
        spi_dbg("close spi device '%s'\n", spi->devname);
        close(spi->fd);
    }

    memset(spi, 0, sizeof(*spi));
    spi->fd = -1;
}


 program/lylib/spidev.h

New file
@@ -0,0 +1,75 @@
/*********************************************************************************
 *      Copyright:  (C) 2019 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  spidev.h
 *    Description:  This file is spidev user space API.
 *                 
 *        Version:  1.0.0(2019年08月19日)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "2019年08月19日 23时18分54秒"
 *                 
 ********************************************************************************/
#ifndef  _SPIDEV_H_
#define  _SPIDEV_H_

#include <stdint.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/ioctl.h>
#include <sys/stat.h>
#include <linux/types.h>
#include <linux/spi/spidev.h>

#define DEVNAME_LEN           64

#define DEF_SPI_BPW           8   /* bits per word */
#define DEF_SPI_SPEED         500 /* unit kHZ */
#define DEF_SPI_MODE          SPI_CPHA

//#define SPI_DEBUG
#ifdef  SPI_DEBUG
#define spi_dbg(format,args...) printf(format, ##args)
#else
#define spi_dbg(format,args...) do{} while(0);
#endif

typedef struct spidev_s 
{
    char             devname[DEVNAME_LEN];
    int              fd;
    uint8_t          bits;     /* bits per word */
    uint32_t         speed;   /* max speed in HZ */
    uint32_t         delay;   /* delay usecs */

   /* mode:   SPI_CPHA,SPI_CPOL => <SPI_MODE_0,SPI_MODE_1,SPI_MODE_2,SPI_MODE_3>
    *         SPI_CS_HIGH | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP | SPI_NO_CS 
    *       | SPI_READY | SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD */
    uint32_t         mode;    
} spidev_t;  


/* initialise and open spidev context 
 * NOTE: $speed unit is KHz
 */
extern int spi_init(spidev_t *spi, char *spidev, uint8_t bpw, uint32_t speed, uint32_t delay, uint32_t mode);


/* read size bytes from SPI slave  */
extern int spi_read(spidev_t *spi, char *buf, int size);


/* write nbytes to SPI slave  */
extern int spi_write(spidev_t *spi, char *data, int nbytes);


/* write nbytes and read nbytes to/from SPI slave */
extern int spi_rdwr(spidev_t *spi, char *data,  char *rbuf, int nbytes);


/* terminate and close spidev context  */
extern int spi_term(spidev_t *spi);


#endif   /* ----- #ifndef _SPIDEV_H_  ----- */

New file
			@@ -0,0 +1,210 @@
			/*********************************************************************************
			* Copyright: (C) 2019 LingYun IoT System Studio
			* All rights reserved.
			*
			* Filename: at91_sysGpio.c
			* Description: This file si GPIO API operatore on /sys/class/gpio/xxx
			*
			* Version: 1.0.0(2019年08月26日)
			* Author: Guo Wenxue <guowenxue@gmail.com>
			* ChangeLog: 1, Release initial version on "2019年08月26日 22时28分19秒"
			*
			********************************************************************************/

			#include <stdio.h>
			#include <unistd.h>
			#include <sys/types.h>
			#include <sys/stat.h>
			#include <fcntl.h>
			#include <string.h>
			#include <errno.h>

			#include "at91_sysGpio.h"


			/* export $port in /sys/class/gpio/export */
			int gpio_export(const char *port)
			{
			char fpath[SYSFILE_LEN];
			FILE *fp;
			int pin;

			if(!port)
			{
			gpio_print("invalid input arguments\n");
			return -1;
			}

			snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

			/* GPIO port already export */
			if( !access(fpath, F_OK) )
			{
			gpio_print("%s already export\n", port);
			return 0;
			}

			if( !(fp=fopen(SYSGPIO_EXPORT_PATH, "w")) )
			{
			gpio_print("open '%s' failure: %s\n", SYSGPIO_EXPORT_PATH, strerror(errno));
			return -2;
			}

			pin = at91_port2pin(port);
			fprintf(fp, "%d", pin);

			fclose(fp);

			return 0;
			}


			/* unexport $port in /sys/class/gpio/unexport */
			int gpio_unexport(const char *port)
			{
			char fpath[SYSFILE_LEN];
			FILE *fp;
			int pin;

			if(!port)
			{
			gpio_print("invalid input arguments\n");
			return -1;
			}

			snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

			/* GPIO port not export */
			if( access(fpath, F_OK) )
			{
			gpio_print("%s not export\n", port);
			return 0;
			}

			if( !(fp=fopen(SYSGPIO_UNEXPORT_PATH, "w")) )
			{
			gpio_print("open '%s' failure: %s\n", SYSGPIO_EXPORT_PATH, strerror(errno));
			return -2;
			}

			pin = at91_port2pin(port);
			fprintf(fp, "%d", pin);

			fclose(fp);

			return 0;
			}


			/* configure $port direction as $mode */
			int gpio_config(const char port, const char mode)
			{
			char fpath[SYSFILE_LEN];
			FILE *fp;
			int size;

			if(!port)
			{
			gpio_print("invalid input arguments\n");
			return 0;
			}

			snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

			if( access(fpath, F_OK) ) /* GPIO port not export */
			{
			if( gpio_export(port) < 0 )
			return -1;
			}

			size = SYSFILE_LEN-strlen(fpath);
			strncat(fpath, "/direction", size);
			if( !(fp=fopen(fpath, "w")) )
			{
			gpio_print("open '%s' failure: %s\n", fpath, strerror(errno));
			return -1;
			}

			fputs(mode, fp);

			fclose(fp);

			return 0;
			}



			/* write $value into GPIO $port */
			int gpio_write(const char port, const char value)
			{
			char fpath[SYSFILE_LEN];
			FILE *fp;
			int size;

			if(!port)
			{
			gpio_print("invalid input arguments\n");
			return 0;
			}

			snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

			if( access(fpath, F_OK) ) /* GPIO port not export */
			{
			if( gpio_export(port) < 0 )
			return -1;
			}

			size = SYSFILE_LEN-strlen(fpath);
			strncat(fpath, "/value", size);
			if( !(fp=fopen(fpath, "w")) )
			{
			gpio_print("open '%s' failure: %s\n", fpath, strerror(errno));
			return -1;
			}

			fputs(value, fp);

			fclose(fp);

			return 0;
			}


			/* read gpio value from $port */
			int gpio_read(const char *port)
			{
			char fpath[SYSFILE_LEN];
			FILE *fp;
			int size;
			char v_str[32];

			if(!port)
			{
			gpio_print("invalid input arguments\n");
			return 0;
			}

			snprintf(fpath, SYSFILE_LEN, "%s/%s", SYSGPIO_PATH, port);

			if( access(fpath, F_OK) ) /* GPIO port not export */
			{
			return -1;
			}

			size = SYSFILE_LEN-strlen(fpath);
			strncat(fpath, "/value", size);
			if( !(fp=fopen(fpath, "r")) )
			{
			gpio_print("open '%s' failure: %s\n", fpath, strerror(errno));
			return -1;
			}

			memset(v_str, 0, sizeof(v_str));
			fgets(v_str, sizeof(v_str), fp);

			fclose(fp);

			return atoi(v_str);
			}

New file
			@@ -0,0 +1,62 @@
			/*********************************************************************************
			* Copyright: (C) 2019 LingYun IoT System Studio
			* All rights reserved.
			*
			* Filename: at91_sysGpio.h
			* Description: This file si GPIO API operatore on /sys/class/gpio/xxx
			*
			* Version: 1.0.0(2019年08月26日)
			* Author: Guo Wenxue <guowenxue@gmail.com>
			* ChangeLog: 1, Release initial version on "2019年08月26日 22时28分19秒"
			*
			********************************************************************************/

			#ifndef _AT91_SYSGPIO_H_
			#define _AT91_SYSGPIO_H_

			#include "at91_sysGpioDef.h"

			#define SYSFILE_LEN 64

			#define SYSGPIO_PATH "/sys/class/gpio/"

			#define SYSGPIO_EXPORT_PATH SYSGPIO_PATH"export"
			#define SYSGPIO_UNEXPORT_PATH SYSGPIO_PATH"unexport"

			//#define GPIO_DEBUG_PRINT

			#ifdef GPIO_DEBUG_PRINT
			#define gpio_print(format,args...) printf(format, ##args)
			#else
			#define gpio_print(format,args...) do{} while(0);
			#endif


			/* export $port in /sys/class/gpio/export */
			extern int gpio_export(const char *port);


			/* unexport $port in /sys/class/gpio/unexport */
			extern int gpio_unexport(const char *port);


			#define M_IN "in" /* set GPIO as input mode */
			#define M_OUT "out" /* set GPIO as output mode */
			#define M_HIGH "high" /* set GPIO as output mode and value be high<1> */
			#define M_LOW "low" /* set GPIO as output mode and value be low<0> */
			/* configure $port direction as $mode */
			extern int gpio_config(const char port, const char mode);


			#define V_HIGH "1"
			#define V_LOW "0"
			/* write $value into GPIO $port */
			extern int gpio_write(const char port, const char value);


			/* read gpio value from $port */
			extern int gpio_read(const char *port);

			#endif /* ----- #ifndef _AT91_SYSGPIO_H_ ----- */

New file
			@@ -0,0 +1,221 @@
			/********************************************************************************
			* Copyright: (C) 2019 LingYun IoT System Studio
			* All rights reserved.
			*
			* Filename: at91_sysGpioDef.h
			* Description: This head file
			*
			* Version: 1.0.0(2019年08月26日)
			* Author: Guo Wenxue <guowenxue@gmail.com>
			* ChangeLog: 1, Release initial version on "2019年08月26日 21时46分02秒"
			*
			********************************************************************************/

			#ifndef _AT91_SYSGPIODEF_H_
			#define _AT91_SYSGPIODEF_H_

			#include <ctype.h>
			#include <stdlib.h>

			#define PA(x) "pioA"#x
			#define PB(x) "pioB"#x
			#define PC(x) "pioC"#x
			#define PD(x) "pioD"#x
			#define PE(x) "pioE"#x

			/* SAMA5D44 devided all GPIOs into 5 groups(PA,PB,PC,PD,PE), and each group control 32 Pins
			*
			* This macro used convert PAx,PBx...,PEx to Pin number: 0~158
			* s should be: PA0-PA31, PB0-PB31, PC0-PC31, PD0-PD31, PE0-PE30(158)
			*/
			#define at91_port2pin(p) ((tolower(p[3])-'a')*32 + atoi(p+4) )


			/*+-----------------------------------------------------+
			*\| GPIO PortA: PA0~PA31 defined as "pioA0"-"pioA31" \|
			+-----------------------------------------------------+/

			#define PA0 PA(0)
			#define PA1 PA(1)
			#define PA2 PA(2)
			#define PA3 PA(3)
			#define PA4 PA(4)
			#define PA5 PA(5)
			#define PA6 PA(6)
			#define PA7 PA(7)
			#define PA8 PA(8)
			#define PA9 PA(9)
			#define PA10 PA(10)
			#define PA11 PA(11)
			#define PA12 PA(12)
			#define PA13 PA(13)
			#define PA14 PA(14)
			#define PA15 PA(15)
			#define PA16 PA(16)
			#define PA17 PA(17)
			#define PA18 PA(18)
			#define PA19 PA(19)
			#define PA20 PA(20)
			#define PA21 PA(21)
			#define PA22 PA(22)
			#define PA23 PA(23)
			#define PA24 PA(24)
			#define PA25 PA(25)
			#define PA26 PA(26)
			#define PA27 PA(27)
			#define PA28 PA(28)
			#define PA29 PA(29)
			#define PA30 PA(30)
			#define PA31 PA(31)


			/*+-----------------------------------------------------+
			*\| GPIO PortB: PB0~PB31 defined as "pioB0"-"pioB31" \|
			+-----------------------------------------------------+/

			#define PB0 PB(0)
			#define PB1 PB(1)
			#define PB2 PB(2)
			#define PB3 PB(3)
			#define PB4 PB(4)
			#define PB5 PB(5)
			#define PB6 PB(6)
			#define PB7 PB(7)
			#define PB8 PB(8)
			#define PB9 PB(9)
			#define PB10 PB(10)
			#define PB11 PB(11)
			#define PB12 PB(12)
			#define PB13 PB(13)
			#define PB14 PB(14)
			#define PB15 PB(15)
			#define PB16 PB(16)
			#define PB17 PB(17)
			#define PB18 PB(18)
			#define PB19 PB(19)
			#define PB20 PB(20)
			#define PB21 PB(21)
			#define PB22 PB(22)
			#define PB23 PB(23)
			#define PB24 PB(24)
			#define PB25 PB(25)
			#define PB26 PB(26)
			#define PB27 PB(27)
			#define PB28 PB(28)
			#define PB29 PB(29)
			#define PB30 PB(30)
			#define PB31 PB(31)

			/*+-----------------------------------------------------+
			*\| GPIO PortC: PC0~PC31 defined as "pioC0"-"pioC31" \|
			+-----------------------------------------------------+/

			#define PC0 PC(0)
			#define PC1 PC(1)
			#define PC2 PC(2)
			#define PC3 PC(3)
			#define PC4 PC(4)
			#define PC5 PC(5)
			#define PC6 PC(6)
			#define PC7 PC(7)
			#define PC8 PC(8)
			#define PC9 PC(9)
			#define PC10 PC(10)
			#define PC11 PC(11)
			#define PC12 PC(12)
			#define PC13 PC(13)
			#define PC14 PC(14)
			#define PC15 PC(15)
			#define PC16 PC(16)
			#define PC17 PC(17)
			#define PC18 PC(18)
			#define PC19 PC(19)
			#define PC20 PC(20)
			#define PC21 PC(21)
			#define PC22 PC(22)
			#define PC23 PC(23)
			#define PC24 PC(24)
			#define PC25 PC(25)
			#define PC26 PC(26)
			#define PC27 PC(27)
			#define PC28 PC(28)
			#define PC29 PC(29)
			#define PC30 PC(30)
			#define PC31 PC(31)

			/*+-----------------------------------------------------+
			*\| GPIO PortD: PD0~PD31 defined as "pioD0"-"pioD31" \|
			+-----------------------------------------------------+/

			#define PD0 PD(0)
			#define PD1 PD(1)
			#define PD2 PD(2)
			#define PD3 PD(3)
			#define PD4 PD(4)
			#define PD5 PD(5)
			#define PD6 PD(6)
			#define PD7 PD(7)
			#define PD8 PD(8)
			#define PD9 PD(9)
			#define PD10 PD(10)
			#define PD11 PD(11)
			#define PD12 PD(12)
			#define PD13 PD(13)
			#define PD14 PD(14)
			#define PD15 PD(15)
			#define PD16 PD(16)
			#define PD17 PD(17)
			#define PD18 PD(18)
			#define PD19 PD(19)
			#define PD20 PD(20)
			#define PD21 PD(21)
			#define PD22 PD(22)
			#define PD23 PD(23)
			#define PD24 PD(24)
			#define PD25 PD(25)
			#define PD26 PD(26)
			#define PD27 PD(27)
			#define PD28 PD(28)
			#define PD29 PD(29)
			#define PD30 PD(30)
			#define PD31 PD(31)

			/*+-----------------------------------------------------+
			*\| GPIO PortE: PE0~PE30 defined as "pioE0"-"pioE30" \|
			+-----------------------------------------------------+/

			#define PE0 PE(0)
			#define PE1 PE(1)
			#define PE2 PE(2)
			#define PE3 PE(3)
			#define PE4 PE(4)
			#define PE5 PE(5)
			#define PE6 PE(6)
			#define PE7 PE(7)
			#define PE8 PE(8)
			#define PE9 PE(9)
			#define PE10 PE(10)
			#define PE11 PE(11)
			#define PE12 PE(12)
			#define PE13 PE(13)
			#define PE14 PE(14)
			#define PE15 PE(15)
			#define PE16 PE(16)
			#define PE17 PE(17)
			#define PE18 PE(18)
			#define PE19 PE(19)
			#define PE20 PE(20)
			#define PE21 PE(21)
			#define PE22 PE(22)
			#define PE23 PE(23)
			#define PE24 PE(24)
			#define PE25 PE(25)
			#define PE26 PE(26)
			#define PE27 PE(27)
			#define PE28 PE(28)
			#define PE29 PE(29)
			#define PE30 PE(30)


			#endif /* ----- #ifndef _AT91_SYSGPIODEF_H_ ----- */

New file
			@@ -0,0 +1,255 @@
			/*********************************************************************************
			* Copyright: (C) 2019 LingYun IoT System Studio
			* All rights reserved.
			*
			* Filename: spidev.c
			* Description: This file is spidev user space API.
			*
			* Version: 1.0.0(2019年08月19日)
			* Author: Guo Wenxue <guowenxue@gmail.com>
			* ChangeLog: 1, Release initial version on "2019年08月19日 23时18分54秒"
			*
			********************************************************************************/
			#include <unistd.h>
			#include <stdlib.h>
			#include <string.h>
			#include "spidev.h"

			int spi_init(spidev_t spi, char spidev, uint8_t bpw, uint32_t speed, uint32_t delay, uint32_t mode)
			{
			int rv = 0;

			if( !spi \|\| !spidev )
			{
			spi_dbg("Invalid input arguments\n");
			return -1;
			}

			memset(spi, 0, sizeof(*spi));

			strncpy(spi->devname, spidev, DEVNAME_LEN);
			spi->bits = bpw;
			spi->speed = speed1000; / speed unit is KHz */
			spi->delay = delay;
			spi->mode = mode;

			spi->fd = open(spidev, O_RDWR);
			if( spi->fd < 0)
			{
			spi_dbg("Open SPI device '%s' failure: %s\n", spidev, strerror(errno));
			rv = -2;
			goto cleanup;
			}

			/* set bits per word */
			if( ioctl(spi->fd, SPI_IOC_WR_BITS_PER_WORD, &bpw) < 0 )
			{
			spi_dbg("Set SPI '%s' bit per words to [%d] failure: %s\n", spidev, bpw, strerror(errno));
			rv = -3;
			goto cleanup;
			}

			/* set bits per word */
			if( ioctl(spi->fd, SPI_IOC_WR_MAX_SPEED_HZ, &spi->speed) < 0 )
			{
			spi_dbg("Set SPI '%s' speed to %dKHz failure: %s\n", spidev, speed, strerror(errno));
			rv = -4;
			goto cleanup;
			}

			/* set spi mode */
			if( ioctl(spi->fd, SPI_IOC_WR_MODE32, &mode) < 0 )
			{
			spi_dbg("Set SPI '%s' mode to [0x%0x] failure: %s\n", spidev, mode, strerror(errno));
			rv = -5;
			goto cleanup;
			}

			cleanup:
			if( rv < 0 )
			{
			close(spi->fd);
			}

			return rv;
			}

			int spi_read(spidev_t spi, char buf, int size)
			{
			int rv = 0;
			void *dummy_buf;

			struct spi_ioc_transfer tr =
			{
			.rx_buf = (unsigned long)buf,
			.len = size,
			.delay_usecs = spi->delay,
			.speed_hz = spi->speed,
			.bits_per_word = spi->bits,
			};

			if( !spi \|\| !buf \|\| size<=0 )
			{
			spi_dbg("Invalid input arguments\n");
			return -1;
			}

			if( ! (dummy_buf=malloc(tr.len)) )
			{
			spi_dbg("spi_read malloc failure: %s\n", strerror(errno));
			return -2;
			}
			tr.tx_buf = (unsigned long)dummy_buf;

			if ( spi->mode & (SPI_TX_QUAD\|SPI_RX_QUAD) )
			tr.tx_nbits = 4;

			if ( spi->mode & (SPI_TX_DUAL\|SPI_RX_DUAL) )
			tr.tx_nbits = 2;

			if (!(spi->mode & SPI_LOOP))
			{
			if (spi->mode & (SPI_TX_QUAD\|SPI_TX_DUAL))
			tr.rx_buf = 0;
			else if (spi->mode & (SPI_RX_QUAD\|SPI_RX_DUAL))
			tr.tx_buf = 0;
			}

			if( ioctl(spi->fd, SPI_IOC_MESSAGE(1), &tr) < 0)
			{
			spi_dbg("spi_read SPI_IOC_MESSAGE failure: %s\n", strerror(errno));
			rv = -3;
			goto cleanup;
			}

			cleanup:
			if( dummy_buf )
			{
			free( dummy_buf );
			}

			return rv;
			}


			int spi_write(spidev_t spi, char data, int nbytes)
			{
			int rv = 0;
			void *dummy_buf;

			struct spi_ioc_transfer tr =
			{
			.tx_buf = (unsigned long)data,
			.len = nbytes,
			.delay_usecs = spi->delay,
			.speed_hz = spi->speed,
			.bits_per_word = spi->bits,
			};


			if( !spi \|\| !data \|\| nbytes<= 0)
			{
			spi_dbg("Invalid input arguments\n");
			return -1;
			}

			if( ! (dummy_buf=malloc(tr.len)) )
			{
			spi_dbg("spi_read malloc failure: %s\n", strerror(errno));
			return -1;
			}
			tr.rx_buf = (unsigned long)dummy_buf;

			if ( spi->mode & (SPI_TX_QUAD\|SPI_RX_QUAD) )
			tr.tx_nbits = 4;

			if ( spi->mode & (SPI_TX_DUAL\|SPI_RX_DUAL) )
			tr.tx_nbits = 2;

			if (!(spi->mode & SPI_LOOP))
			{
			if (spi->mode & (SPI_TX_QUAD\|SPI_TX_DUAL))
			tr.rx_buf = 0;
			else if (spi->mode & (SPI_RX_QUAD\|SPI_RX_DUAL))
			tr.tx_buf = 0;
			}

			if( ioctl(spi->fd, SPI_IOC_MESSAGE(1), &tr) < 0)
			{
			spi_dbg("spi_read SPI_IOC_MESSAGE failure: %s\n", strerror(errno));
			rv = -2;
			goto cleanup;
			}

			cleanup:
			if( dummy_buf )
			{
			free( dummy_buf );
			}

			return rv;
			}

			int spi_rdwr(spidev_t spi, char data, char *rbuf, int nbytes)
			{
			int rv = 0;

			struct spi_ioc_transfer tr =
			{
			.tx_buf = (unsigned long)data,
			.rx_buf = (unsigned long)rbuf,
			.len = nbytes,
			.delay_usecs = spi->delay,
			.speed_hz = spi->speed,
			.bits_per_word = spi->bits,
			};

			if( !spi \|\| !data \|\| nbytes<=0 )
			{
			spi_dbg("Invalid input arguments\n");
			return -1;
			}


			if ( spi->mode & (SPI_TX_QUAD\|SPI_RX_QUAD) )
			tr.tx_nbits = 4;

			if ( spi->mode & (SPI_TX_DUAL\|SPI_RX_DUAL) )
			tr.tx_nbits = 2;

			if (!(spi->mode & SPI_LOOP))
			{
			if (spi->mode & (SPI_TX_QUAD\|SPI_TX_DUAL))
			tr.rx_buf = 0;
			else if (spi->mode & (SPI_RX_QUAD\|SPI_RX_DUAL))
			tr.tx_buf = 0;
			}


			if( ioctl(spi->fd, SPI_IOC_MESSAGE(1), &tr) < 0)
			{
			spi_dbg("spi_read SPI_IOC_MESSAGE failure: %s\n", strerror(errno));
			rv = -3;
			}

			return rv;
			}

			int spi_term(spidev_t *spi)
			{
			if( !spi )
			{
			spi_dbg("Invalid input arguments\n");
			return -1;
			}

			if(spi->fd)
			{
			spi_dbg("close spi device '%s'\n", spi->devname);
			close(spi->fd);
			}

			memset(spi, 0, sizeof(*spi));
			spi->fd = -1;
			}

New file
			@@ -0,0 +1,75 @@
			/*********************************************************************************
			* Copyright: (C) 2019 LingYun IoT System Studio
			* All rights reserved.
			*
			* Filename: spidev.h
			* Description: This file is spidev user space API.
			*
			* Version: 1.0.0(2019年08月19日)
			* Author: Guo Wenxue <guowenxue@gmail.com>
			* ChangeLog: 1, Release initial version on "2019年08月19日 23时18分54秒"
			*
			********************************************************************************/
			#ifndef _SPIDEV_H_
			#define _SPIDEV_H_

			#include <stdint.h>
			#include <fcntl.h>
			#include <sys/ioctl.h>
			#include <linux/ioctl.h>
			#include <sys/stat.h>
			#include <linux/types.h>
			#include <linux/spi/spidev.h>

			#define DEVNAME_LEN 64

			#define DEF_SPI_BPW 8 /* bits per word */
			#define DEF_SPI_SPEED 500 /* unit kHZ */
			#define DEF_SPI_MODE SPI_CPHA

			//#define SPI_DEBUG
			#ifdef SPI_DEBUG
			#define spi_dbg(format,args...) printf(format, ##args)
			#else
			#define spi_dbg(format,args...) do{} while(0);
			#endif

			typedef struct spidev_s
			{
			char devname[DEVNAME_LEN];
			int fd;
			uint8_t bits; /* bits per word */
			uint32_t speed; /* max speed in HZ */
			uint32_t delay; /* delay usecs */

			/* mode: SPI_CPHA,SPI_CPOL => <SPI_MODE_0,SPI_MODE_1,SPI_MODE_2,SPI_MODE_3>
			* SPI_CS_HIGH \| SPI_LSB_FIRST \| SPI_3WIRE \| SPI_LOOP \| SPI_NO_CS
			* \| SPI_READY \| SPI_TX_DUAL \| SPI_TX_QUAD \| SPI_RX_DUAL \| SPI_RX_QUAD */
			uint32_t mode;
			} spidev_t;


			/* initialise and open spidev context
			* NOTE: $speed unit is KHz
			*/
			extern int spi_init(spidev_t spi, char spidev, uint8_t bpw, uint32_t speed, uint32_t delay, uint32_t mode);


			/* read size bytes from SPI slave */
			extern int spi_read(spidev_t spi, char buf, int size);


			/* write nbytes to SPI slave */
			extern int spi_write(spidev_t spi, char data, int nbytes);


			/* write nbytes and read nbytes to/from SPI slave */
			extern int spi_rdwr(spidev_t spi, char data, char *rbuf, int nbytes);


			/* terminate and close spidev context */
			extern int spi_term(spidev_t *spi);


			#endif /* ----- #ifndef _SPIDEV_H_ ----- */