huawei-mrd-kernel/arch/um/drivers/null.c

51 lines
970 B
C

/*
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
* Licensed under the GPL
*/
#include <stddef.h>
#include <errno.h>
#include <fcntl.h>
#include "chan_user.h"
#include <os.h>
/* This address is used only as a unique identifier */
static int null_chan;
static void *null_init(char *str, int device, const struct chan_opts *opts)
{
return &null_chan;
}
static int null_open(int input, int output, int primary, void *d,
char **dev_out)
{
int fd;
*dev_out = NULL;
fd = open(DEV_NULL, O_RDWR);
return (fd < 0) ? -errno : fd;
}
static int null_read(int fd, char *c_out, void *unused)
{
return -ENODEV;
}
static void null_free(void *data)
{
}
const struct chan_ops null_ops = {
.type = "null",
.init = null_init,
.open = null_open,
.close = generic_close,
.read = null_read,
.write = generic_write,
.console_write = generic_console_write,
.window_size = generic_window_size,
.free = null_free,
.winch = 0,
};