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
#include
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
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
* * 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 #include #include #include #include #include #include #include #include #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！
