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TODO:
- Rx block size is limited to < 2048, hardware bug?
- Group size is limited to < page size, kernel alloc/mmap API issues
- test whether Tx is transmitting data from provided buffers
- handle device unplug case
- handle temperature above threshold
- use bus address instead of physical address for DMA
- support for snapshot mode
- audit userspace interfaces
- get reserved major/minor if needed
Sample Code:
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <poll.h>
#include <stdio.h>
#include <error.h>
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <sysfs/libsysfs.h>
#include <poch.h>
struct pconsume {
uint32_t * offsets;
uint32_t nfetch;
uint32_t nflush;
};
uint32_t offsets[10];
void process_group(unsigned char *buf, uint32_t size)
{
uint16_t *buf16 = (uint16_t *)buf;
printf("RX: %p %u %04x %04x %04x %04x %04x %04x\n", buf, size,
buf16[0], buf16[1], buf16[2], buf16[3], buf16[4], buf16[5]);
}
int main()
{
struct sysfs_attribute *attr;
char *path;
int ret;
unsigned long mmap_size;
int fd;
unsigned char *cbuf;
uint32_t nflush;
struct pollfd poll_fds;
int count = 0;
int i;
path = "/sys/class/pocketchange/poch0/ch0/block_size";
attr = sysfs_open_attribute(path);
ret = sysfs_write_attribute(attr, "256", strlen("256"));
if (ret == -1)
error(1, errno, "error writing attribute %s", path);
sysfs_close_attribute(attr);
path = "/sys/class/pocketchange/poch0/ch0/group_size";
attr = sysfs_open_attribute(path);
ret = sysfs_write_attribute(attr, "4096", strlen("4096"));
if (ret == -1)
error(1, errno, "error writing attribute %s", path);
sysfs_close_attribute(attr);
path = "/sys/class/pocketchange/poch0/ch0/group_count";
attr = sysfs_open_attribute(path);
ret = sysfs_write_attribute(attr, "64", strlen("64"));
if (ret == -1)
error(1, errno, "error writing attribute %s", path);
sysfs_close_attribute(attr);
fd = open("/dev/ch0", O_RDWR);
if (fd == -1)
error(1, errno, "error opening device node");
path = "/sys/class/pocketchange/poch0/ch0/mmap_size";
attr = sysfs_open_attribute(path);
ret = sysfs_read_attribute(attr);
if (ret == -1)
error(1, errno, "error reading attribute %s", path);
printf("%s", attr->value);
sscanf(attr->value, "%lu", &mmap_size);
sysfs_close_attribute(attr);
cbuf = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE, fd, 0);
if (cbuf == MAP_FAILED)
error(1, errno, "error mapping DMA buffers");
ret = ioctl(fd, POCH_IOC_TRANSFER_START, 0);
if (ret == -1)
error(1, errno, "error starting transfer");
nflush = 0;
while (1) {
struct pconsume consume;
consume.offsets = offsets;
consume.nfetch = 10;
consume.nflush = nflush;
ret = ioctl(fd, POCH_IOC_CONSUME, &consume);
if (ret == -1)
error(1, errno, "error consuming groups");
nflush = consume.nfetch;
for (i = 0; i < nflush; i++) {
process_group(cbuf + consume.offsets[i], 4096);
count++;
if (count == 1000)
break;
}
if (count == 1000)
break;
}
ret = ioctl(fd, POCH_IOC_TRANSFER_STOP, 0);
if (ret == -1)
error(1, errno, "error starting transfer");
return 0;
}
Please send patches to Greg Kroah-Hartman <greg@kroah.com> and
Vijay Kumar <vijaykumar@bravegnu.org> and Jaya Kumar <jayakumar.lkml@gmail.com>
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