2

使用 Windows，我可以使用以下简化代码轻松地与我的 USB 设备进行通信：

DWORD dwJunk;    // discard results from DeviceIOControl()
int   iReply;
char  cBuffer[100];
// cBuffer is initialized here.
HANDLE hDevice; // handle to the drive to be examined 
CString sDrive = _T(\\\\.\\H:); // drive H: for this test
hDevice = CreateFile(sDrive,            // drive to open
   GENERIC_READ | GENERIC_WRITE,        // read and write access to the drive
   FILE_SHARE_READ | FILE_SHARE_WRITE,  // share mode           
   NULL,                                // default security attributes
   OPEN_EXISTING,                       // disposition
   0,                                   // file attributes
   NULL);                               // do not copy file attributes

iReply = DeviceIoControl(hDevice, IOCTL_SCSI_PASS_THROUGH_DIRECT, &cBuffer, sizeof(cBuffer), &cBuffer, sizeof(cBuffer), &dwJunk, (LPOVERLAPPED)NULL);

我正在尝试在 linux 中做同样的事情，但无法弄清楚 ioctrl() 参数，或者更好地放置结构。非常感谢代码片段。谢谢。

4

3 回答 3

1

这里还有一些文档：

于 2013-03-05T23:05:55.993 回答
1

不幸的是，我使用您的链接修改的代码没有返回任何结果。这是我使用的剥离代码。ioctl() 返回没有错误：

#define DEF_TIMEOUT 5000 // 5 seconds
char cDiskName[] = "/dev/sg3";
int fd = open(cDiskName, O_RDWR);
if (fd < 0)
{
  printf("Open error: %s, errno=%d (%s)\n", cDiskName, errno, strerror(errno));
  return 1;
}

unsigned char turCmbBlk[] = {0x00, 0, 0, 0, 0, 0};
struct sg_io_hdr io_hdr;

unsigned char cIOBuffer[100];

// buffer initialization code omitted

memset(&io_hdr, 0, sizeof(struct sg_io_hdr));
io_hdr.interface_id = 'S';
io_hdr.cmd_len = sizeof(turCmbBlk);
io_hdr.mx_sb_len = sizeof(cIOBuffer);
io_hdr.dxfer_direction = SG_DXFER_NONE;
io_hdr.cmdp = turCmbBlk;
io_hdr.sbp = cIOBuffer;
io_hdr.timeout = DEF_TIMEOUT;
if (ioctl(fd, SG_IO, &io_hdr) < 0)
{
  printf("ioctl error: errno=%d (%s)\n", errno, strerror(errno));
}

// Code returned here without any errors but cIOBuffer remains unchanged.

也许呼叫需要不同的请求代码？

于 2013-02-11T15:50:30.690 回答
0

看这里：

#include <sys/ioctl.h>

int ioctl(int d, int request, ...);

参数：

  1. 文件描述符（必须打开！）
  2. 请求代码号（取决于设备）
  3. 指向内存的无类型指针（去往/来自驱动程序）

例子

#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <linux/usbdevice_fs.h>

void main(int argc, char **argv)
{
    const char *filename;
    int fd;

    filename = argv[1];

    fd = open(filename, O_WRONLY);
    ioctl(fd, USBDEVFS_RESET, 0);

    close(fd);

    return;
}

文档：

编辑

#define BUFF_SIZE 100 // - Buffersize

#define DEF_TIMEOUT 5000 // 5 seconds
char cDiskName[] = "/dev/sg3";
int fd = open(cDiskName, O_RDWR);
if (fd < 0)
{
  printf("Open error: %s, errno=%d (%s)\n", cDiskName, errno, strerror(errno));
  return 1;
}

unsigned char turCmbBlk[] = {0x00, 0, 0, 0, 0, 0};
struct sg_io_hdr *p = (struct sg_io_hdr *) malloc(sizeof(struct sg_io_hdr)); // - dynamic memory allocation - free() required somewhere

unsigned char cIOBuffer[BUFF_SIZE];
unsigned char replyBuffer[BUFF_SIZE]; // - dxfer buffer

// buffer initialization code omitted

memset(p, 0, sizeof(struct sg_io_hdr));
p->interface_id = 'S';
p->cmd_len = sizeof(turCmbBlk);
p->mx_sb_len = BUFF_SIZE;
p->dxfer_direction = SG_DXFER_NONE;
p->cmdp = turCmbBlk;
p->sbp = cIOBuffer;
p->timeout = DEF_TIMEOUT;
p->flags = SG_FLAG_DIRECT_IO; // - Does this help?
p->dxferp = replyBuffer; // - Set dxferp buffer - (A)
p->dxfer_len = BUFF_SIZE; // - buffersize

if (ioctl(fd, SG_IO, p) < 0)
{
  printf("ioctl error: errno=%d (%s)\n", errno, strerror(errno));
}

// Code returned here without any errors but cIOBuffer remains unchanged.

注意（A）：请尝试设置您在此处工作的输入/输出缓冲区。

文档：

于 2013-02-10T14:52:16.977 回答