Linux2.6.32下SPI驱动的移植如下图所示:
下面需要修改部分内核代码,具体操作如下:
1. 修改arch/arm/mach-s3c2440/mach-mini2440.c文件
在include头文件代码行之后增加如下代码
//spi add by shiguang
#include <linux/spi/spi.h>
#include <mach/spi.h>
static struct spi_board_info s3c2410_spi0_board[] = {
[0] = {
.modalias = "spidev",
.bus_num = 0,
.chip_select = 0,
.irq = IRQ_EINT9,
.max_speed_hz = 500*1000,
},
};
static struct s3c2410_spi_info s3c2410_spi0_platdata = {
.pin_cs = S3C2410_GPG(2),
.num_cs = 1,
.bus_num = 0,
};
//end add spi
然后在函数__initmini2440_machine_init的开头增加下列代码
//spi add by shiguang
s3c_device_spi0.dev.platform_data=&s3c2410_spi0_platdata;
spi_register_board_info(s3c2410_spi0_board,ARRAY_SIZE(s3c2410_spi0_board));
//end spi
在mini2440_devices数组的最后中添加
&s3c_device_spi0,// add by shiguang
2.修改drivers/spi/spi_s3c24xx.c文件
在文件开头增加下列代码
//add by shiguang
#include <mach/regs-gpio.h>
在s3c24xx_spi_initialsetup函数结尾增加下列代码
// add by shiguang
s3c2410_gpio_cfgpin(hw->pdata->pin_cs,S3C2410_GPIO_OUTPUT);
s3c2410_gpio_cfgpin(0x8B, S3C2410_GPIO_SFN2);
s3c2410_gpio_cfgpin(0x8C, S3C2410_GPIO_SFN2);
s3c2410_gpio_cfgpin(0x8D, S3C2410_GPIO_SFN2);
// end add
3. 最后重新编译内核
4. 应用程序测试
测设程序取至Linux源码包下的/home/youshan/linux-2.6.32.2/Documentation/spi/spidev_test.c ,这里我再把它贴一遍。
-
/*
-
* SPI testing utility (using spidev driver)
-
*
-
* Copyright (c) 2007 MontaVista Software, Inc.
-
* Copyright (c) 2007 Anton Vorontsov <avorontsov@ru.mvista.com>
-
*
-
* 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.
-
*
-
* Cross-compile with cross-gcc -I/path/to/cross-kernel/include
-
*/
-
-
#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 ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
-
-
static void pabort(const char *s)
-
{
-
perror(s);
-
abort();
-
}
-
-
static const char *device = "/dev/spidev1.1";
-
static uint8_t mode;
-
static uint8_t bits = 8;
-
static uint32_t speed = 500000;
-
static uint16_t delay;
-
-
static void transfer(int fd)
-
{
-
int ret;
-
uint8_t tx[] = {
-
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
-
0x40, 0x00, 0x00, 0x00, 0x00, 0x95,
-
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
-
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
-
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
-
0xDE, 0xAD, 0xBE, 0xEF, 0xBA, 0xAD,
-
0xF0, 0x0D,
-
};
-
uint8_t rx[ARRAY_SIZE(tx)] = {0, };
-
struct spi_ioc_transfer tr = {
-
.tx_buf = (unsigned long)tx,
-
.rx_buf = (unsigned long)rx,
-
.len = ARRAY_SIZE(tx),
-
.delay_usecs = delay,
-
.speed_hz = speed,
-
.bits_per_word = bits,
-
};
-
-
ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
-
if (ret == 1)
-
pabort("can't send spi message");
-
-
for (ret = 0; ret < ARRAY_SIZE(tx); ret++) {
-
if (!(ret % 6))
-
puts("");
-
printf("%.2X ", rx[ret]);
-
}
-
puts("");
-
}
-
-
static void print_usage(const char *prog)
-
{
-
printf("Usage: %s [-DsbdlHOLC3]\n", prog);
-
puts(" -D --device device to use (default /dev/spidev1.1)\n"
-
" -s --speed max speed (Hz)\n"
-
" -d --delay delay (usec)\n"
-
" -b --bpw bits per word \n"
-
" -l --loop loopback\n"
-
" -H --cpha clock phase\n"
-
" -O --cpol clock polarity\n"
-
" -L --lsb least significant bit first\n"
-
" -C --cs-high chip select active high\n"
-
" -3 --3wire SI/SO signals shared\n");
-
exit(1);
-
}
-
-
static void parse_opts(int argc, char *argv[])
-
{
-
while (1) {
-
static const struct option lopts[] = {
-
{ "device", 1, 0, 'D' },
-
{ "speed", 1, 0, 's' },
-
{ "delay", 1, 0, 'd' },
-
{ "bpw", 1, 0, 'b' },
-
{ "loop", 0, 0, 'l' },
-
{ "cpha", 0, 0, 'H' },
-
{ "cpol", 0, 0, 'O' },
-
{ "lsb", 0, 0, 'L' },
-
{ "cs-high", 0, 0, 'C' },
-
{ "3wire", 0, 0, '3' },
-
{ "no-cs", 0, 0, 'N' },
-
{ "ready", 0, 0, 'R' },
-
{ NULL, 0, 0, 0 },
-
};
-
int c;
-
-
c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR", lopts, NULL);
-
-
if (c == -1)
-
break;
-
-
switch (c) {
-
case 'D':
-
device = optarg;
-
break;
-
case 's':
-
speed = atoi(optarg);
-
break;
-
case 'd':
-
delay = atoi(optarg);
-
break;
-
case 'b':
-
bits = atoi(optarg);
-
break;
-
case 'l':
-
mode |= SPI_LOOP;
-
break;
-
case 'H':
-
mode |= SPI_CPHA;
-
break;
-
case 'O':
-
mode |= SPI_CPOL;
-
break;
-
case 'L':
-
mode |= SPI_LSB_FIRST;
-
break;
-
case 'C':
-
mode |= SPI_CS_HIGH;
-
break;
-
case '3':
-
mode |= SPI_3WIRE;
-
break;
-
case 'N':
-
mode |= SPI_NO_CS;
-
break;
-
case 'R':
-
mode |= SPI_READY;
-
break;
-
default:
-
print_usage(argv[0]);
-
break;
-
}
-
}
-
}
-
-
int main(int argc, char *argv[])
-
{
-
int ret = 0;
-
int fd;
-
-
parse_opts(argc, argv);
-
-
fd = open(device, O_RDWR);
-
if (fd < 0)
-
pabort("can't open device");
-
-
/*
-
* spi mode
-
*/
-
ret = ioctl(fd, SPI_IOC_WR_MODE, &mode);
-
if (ret == -1)
-
pabort("can't set spi mode");
-
-
ret = ioctl(fd, SPI_IOC_RD_MODE, &mode);
-
if (ret == -1)
-
pabort("can't get spi mode");
-
-
/*
-
* bits per word
-
*/
-
ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
-
if (ret == -1)
-
pabort("can't set bits per word");
-
-
ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
-
if (ret == -1)
-
pabort("can't get bits per word");
-
-
/*
-
* max speed hz
-
*/
-
ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
-
if (ret == -1)
-
pabort("can't set max speed hz");
-
-
ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
-
if (ret == -1)
-
pabort("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);
-
-
transfer(fd);
-
-
close(fd);
-
-
return ret;
-
}
只需将mini2440的SPI rx和tx短接就可以收到数据。结果如下图所示:
测试完毕!OVER!
转载自:http://blog.csdn.net/stephen_yu/article/details/7205671
阅读(5861) | 评论(0) | 转发(0) |