1 // Copyright 2016 The Fuchsia Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include <ddk/binding.h>
6 #include <ddk/device.h>
7 #include <ddk/driver.h>
8
9 #include <zircon/types.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13
14 // null is the /dev/null device.
15
null_read(void * ctx,void * buf,size_t count,zx_off_t off,size_t * actual)16 static zx_status_t null_read(void* ctx, void* buf, size_t count, zx_off_t off, size_t* actual) {
17 *actual = 0;
18 return ZX_OK;
19 }
20
null_write(void * ctx,const void * buf,size_t count,zx_off_t off,size_t * actual)21 static zx_status_t null_write(void* ctx, const void* buf, size_t count, zx_off_t off, size_t* actual) {
22 *actual = count;
23 return ZX_OK;
24 }
25
26 static zx_protocol_device_t null_device_proto = {
27 .version = DEVICE_OPS_VERSION,
28 .read = null_read,
29 .write = null_write,
30 };
31
null_bind(void * ctx,zx_device_t * parent,void ** cookie)32 zx_status_t null_bind(void* ctx, zx_device_t* parent, void** cookie) {
33 device_add_args_t args = {
34 .version = DEVICE_ADD_ARGS_VERSION,
35 .name = "null",
36 .ops = &null_device_proto,
37 };
38
39 zx_device_t* dev;
40 return device_add(parent, &args, &dev);
41 }
42