at91sam9261的板子，在调试SPI，但是老是不对，感觉根本没读书据，内核中我已经添加了spi1，添加的方法如下：
在 linux-2.6.24/arch/arm/mach-at91下面的board-sam9261ek.c 中的ek_spi_devices[]中添加如下代码
{ /* add a spi1 device */
.modalias ="spidev",
.bus_num =1,
.chip_select =0,
.max_speed_hz =15 * 1000 * 1000,
},
{ /* add a spi1 device */
.modalias ="spidev",
.bus_num =1,
.chip_select =1,
.max_speed_hz =15 * 1000 * 1000,
},
在cat /dev/spi1的时候，时钟上有反应
上面添加代码有没有对阿，请指教（内核里面已经添加spi支持）
但是在我测试的时候不对，首先用了内核里面的spidev_test.c输出结果全部是0，然后我根据网上的资料写了一个测试程序，但是还是输出不对，都是0，我的输出显示如下：
open spi port=1
spi mode: 1
bits per word: 8
max speed: 500000 Hz (500 KHz)
from__main_buf:
AA BB CC DD
send_buf_test
AA BB CC DD
addr_frommain
AA BB CC DD
tx_write2read
AA BB CC DD
read_[0].tx_buf:
AA BB CC DD
read_xfer[1].rx_buf:
00 00 00 00
buf_return2main:
00 00 00 00
MAIN_data;
00 00 00 00
源代码如下：
#include <stdint.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/spi/spidev.h>
#define UCHAR unsigned char
#define MAXNUM_SPI 3
static int fd_spi[MAXNUM_SPI] = {-1, -1};
static uint8_t mode=SPI_MODE_1;
static uint8_t bits = 8;
static uint32_t speed = 500000;
#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
#define SIZE_APPSPI_RCVBUF 1024
struct spi_ioc_transfer tfer[1];
struct spi_ioc_transfer xfer[2];
struct appspi_rcvst
{
char buf[SIZE_APPSPI_RCVBUF];
int len;
int head;
};
static struct appspi_rcvst appspi_rcvbuf[MAXNUM_SPI];
int appspi_open(unsigned int port)
{
int fd;
char dev[32];
int ret;
if(-1 != fd_spi[port])
close(fd_spi[port]);
if(port==0) sprintf(dev, "/dev/spi0");
else if(port==1) sprintf(dev, "/dev/spi1");
fd = open(dev, O_RDWR);
if(fd<0)
{
printf("can't open spi device");
return 1;
}
printf("open spi port=%d\n",port);
ret = ioctl(fd, SPI_IOC_WR_MODE,&mode);
if (ret == -1)
printf("can't set spi mode");
ret = ioctl(fd, SPI_IOC_RD_MODE,&mode);
if (ret == -1)
printf("can't get spi mode");
ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
if (ret == -1)
printf("can't set bits per word");
ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
if (ret == -1)
printf("can't get bits per word");
ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
if (ret == -1)
printf("can't set max speed hz");
ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
if (ret == -1)
printf("can't get max speed hz");
printf("spi mode: %d\n", mode);
printf("bits per word: %d\n", bits);
printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
fd_spi[port]=fd;
appspi_rcvbuf[port].len=0;
return 0;
}
void appspi_close(unsigned int port)
{
if((port >= MAXNUM_SPI) || (-1 == fd_spi[port]))
return;
close(fd_spi[port]); //这样关闭是什么意思。关闭设备不应该是close(fd);其中fd是打开时的返回值；??
fd_spi[port] = -1;
}
int appspi_send(unsigned int port, UCHAR *buf, unsigned int len)
{
int i;
int ret;
int fd;
//add by Gan
// 20120227
UCHAR *buftest;
//add end
if(port >= MAXNUM_SPI)
return -1;
fd = fd_spi[port];
if(fd < 0)
{
appspi_open(port);
fd = fd_spi[port];
if(fd<0)
return -1;
}
// struct spi_ioc_transfer tfer[1];
memset(tfer, 0, sizeof(tfer));
// tfer[0].tx_buf = (__u64)(int) buf;
tfer[0].len = len;
//add by Gan
//20120227
tfer[0].tx_buf = (__u64)buf;
buftest=tfer[0].tx_buf;
//add end
printf("from__main_buf:\n");
for(i=0;i<4;i++)
printf("%.2X\t",*buf++);
printf("\n");
ret = ioctl(fd, SPI_IOC_MESSAGE(1), tfer);
if (ret < 0)
{
printf("Error: SPI_IOC_MESSAGEn");
return -1;
}
printf("send_buf_test\n");
for(i=0;i<4;i++)
printf("%.2X\t",*buftest++);
printf("\n");
return ret;
}
//int appspi_recv(unsigned int port,UCHAR addr, UCHAR *buf, unsigned int len)
//reverse by Gan
//20120027
int appspi_recv(unsigned int port,UCHAR *addr, UCHAR *buf, unsigned int len)
//reverse end
{
int i;
int ret;
int fd;
UCHAR tx[4];
UCHAR *bp;
UCHAR *addr_save=addr;
UCHAR *tx_test;
if(port>= MAXNUM_SPI)
return -1;
fd = fd_spi[port];
if(fd < 0)
{
appspi_open(port);
fd = fd_spi[port];
if(fd<0)
return -1;
}
// struct spi_ioc_transfer xfer[2];
memset(xfer, 0, sizeof(xfer));
// tx[0]=addr;
// xfer[0].tx_buf =(__u64)(int)tx;
//reverse by Gan
//20120027
for(i=0;i<4;i++)
tx=*addr++;
addr=addr_save;
printf("addr_frommain\n");
for(i=0;i<4;i++)
printf("%.2X\t",*addr++);
printf("\n");
printf("tx_write2read\n");
for(i=0;i<4;i++)
printf("%.2X\t",tx);
printf("\n");
xfer[0].cs_change=1;
xfer[0].tx_buf =(__u64)tx;
xfer[1].rx_buf =(__u64)buf;
tx_test=xfer[0].tx_buf;
//reverse end
xfer[0].len = 1;
// xfer[1].rx_buf =(__u64)(int) buf;
xfer[1].len =len;
//add by Gan
//20120227
ret = ioctl(fd, SPI_IOC_MESSAGE(2), xfer);
printf("read_[0].tx_buf:\n");
for(i=0;i<4;i++)
printf("%.2X\t",*tx_test++);
printf("\n");
bp=xfer[1].rx_buf;
printf("read_xfer[1].rx_buf:\n");
for(i=0;i<4;i++)
printf("%.2X\t",*bp++);
printf("\n");
printf("buf_return2main:\n");
for(i=0;i<4;i++)
printf("%.2X\t",*buf++);
printf("\n");
if (ret < 0)
{
printf("Error: SPI_IOC_MESSAGEn");
return -1;
}
return ret;
}
void main()
{ int i;
UCHAR buf[4]={0xaa,0xbb,0xcc,0xdd};
UCHAR rec[4]={};
unsigned int len= ARRAY_SIZE(buf);
appspi_open(1);
appspi_send(1,buf,len);
appspi_recv(1,buf,rec,len);
printf("MAIN_data;\n");
for(i=0;i<4;i++)
printf("%.2X\t",rec);
printf("\n");
appspi_close(1);
}
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