linux spidev 应用_Linux下SPI驱动的移植和应用程序的测试

今天药忘吃喽~ 2023-01-10 03:52 201阅读 0赞

Linux2.6.32下SPI驱动的移植如下图所示：

![0\_1313736442GQEE.gif][0_1313736442GQEE.gif]

![0\_13137364833tl3.gif][0_13137364833tl3.gif]

![0\_131373658583oH.gif][0_131373658583oH.gif]

![0\_1313736610Y9yl.gif][0_1313736610Y9yl.gif]

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

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

![0\_1313736642vj3Y.gif][0_1313736642vj3Y.gif]

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。

点击(此处)折叠或打开

/\*

\* SPI testing utility (using spidev driver)

\* 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

\#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,

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：

![0\_1313722457W6Kg.gif][0_1313722457W6Kg.gif]

![laugh.gif][]测试完毕！OVER！

转载自：http://blog.csdn.net/stephen\_yu/article/details/7205671

[0_1313736442GQEE.gif]: /images/20221119/354ee5c156f445fd9af9f0685f3eeef8.png
[0_13137364833tl3.gif]: /images/20221119/025a22a0dcb24359b80ca2a3807abd05.png
[0_131373658583oH.gif]: /images/20221119/e0f2301c457a43dfb80d25ae81132949.png
[0_1313736610Y9yl.gif]: /images/20221119/f5157900467e43e0ae070571dab306fc.png
[0_1313736642vj3Y.gif]: /images/20221119/267ba5f17ebd41559e5672da5020732d.png
[0_1313722457W6Kg.gif]: /images/20221119/bbbba44b65d74d149aa186617195aad2.png
[laugh.gif]: /images/20221119/1b926334221f46beb62380990cd3b8f3.png