Linux下SPI驱动的移植和应用程序的测试-白红宇

Linux下SPI驱动的移植和应用程序的测试

阅读量：4137 次

发布时间：2019-05-25

本文共 7482 字，大约阅读时间需要 24 分钟。

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

重启mini2440，查看/dev下的设备文件

[root@ShiGuang /]# ls /dev/spidev0.0 -l

crw-rw---- 1 root root 153, 0 Jan 1 08:00 /dev/spidev0.0

[root@ShiGuang /]#

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：