1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 #ifndef __CMD_H__ 17 #define __CMD_H__ 18 19 #define _IOC_NRBITS 8 20 #define _IOC_TYPEBITS 8 21 22 /* 23 * Let any architecture override either of the following before 24 * including this file. 25 */ 26 27 #ifndef _IOC_SIZEBITS 28 # define _IOC_SIZEBITS 14 29 #endif 30 31 #ifndef _IOC_DIRBITS 32 # define _IOC_DIRBITS 2 33 #endif 34 35 #define _IOC_NRMASK ((1 << _IOC_NRBITS)-1) 36 #define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1) 37 #define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1) 38 #define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1) 39 40 #define _IOC_NRSHIFT 0 41 #define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS) 42 #define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS) 43 #define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS) 44 45 /* 46 * Direction bits, which any architecture can choose to override 47 * before including this file. 48 */ 49 50 #ifndef _IOC_NONE 51 # define _IOC_NONE 0U 52 #endif 53 54 #ifndef _IOC_WRITE 55 # define _IOC_WRITE 1U 56 #endif 57 58 #ifndef _IOC_READ 59 # define _IOC_READ 2U 60 #endif 61 62 63 64 #define _IOC_TYPECHECK(t) (sizeof(t)) 65 #define _IOC(dir,type,nr,size) \ 66 (((dir) << _IOC_DIRSHIFT) | \ 67 ((type) << _IOC_TYPESHIFT) | \ 68 ((nr) << _IOC_NRSHIFT) | \ 69 ((size) << _IOC_SIZESHIFT)) 70 71 72 73 /* used to create numbers */ 74 #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) 75 #define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size))) 76 #define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) 77 #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) 78 79 #endif 80 81