1 /** 2 * @file sys/ioccom.h 3 * @brief Definitions & maros common to ioctl 4 */ 5 6 #ifndef _SYS_IOCCOM_H 7 #define _SYS_IOCCOM_H 8 9 10 #ifdef _BSD_SOURCE 11 12 13 /** 14 * @defgroup IOCTL_common sys/ioccom.h 15 * @brief Definitions & maros common to ioctl() 16 * @ingroup OpenBeOS_POSIX 17 * @ingroup IOCTL 18 * Ioctl values passed as the command (2nd) variable have the 19 * command encoded in the lower word and the size of any parameters 20 * in the upper word (in or out). 21 * The high 3 bits are used to encode whether it's in or out. 22 * Due to this you can't just give an ioctl value, you need to encode 23 * it using macros described in 24 * @ref IOCTL_macros 25 * @{ 26 */ 27 28 /** @defgroup IOCTL_parm ioctl() parameter definitions 29 * @ingroup IOCTL_common 30 * @{ 31 */ 32 /** @def IOC_VOID */ 33 #define IOC_VOID (ulong)0x20000000 34 /** @def IOC_OUT ioctl expects data (output) */ 35 #define IOC_OUT (ulong)0x40000000 36 /** @def IOC_IN ioctl passes a value in */ 37 #define IOC_IN (ulong)0x80000000 38 /** @def IOC_INOUT ioctl passes data in and out */ 39 #define IOC_INOUT (IOC_IN|IOC_OUT) 40 /** @def IOC_DIRMASK */ 41 #define IOC_DIRMASK (ulong)0xe0000000 42 /** @} */ 43 44 /** 45 * @defgroup IOCTL_macros IOCTL macros 46 * These should be used to define the values passed in as cmd to 47 * ioctl() 48 * @ingroup IOCTL_common 49 * @{ 50 */ 51 /** @def IOCPARM_MASK mask used to for following macros */ 52 #define IOCPARM_MASK 0x1fff 53 /** @def IOCPARM_LEN(x) length of the data passed as param */ 54 #define IOCPARM_LEN(x) (((x) >> 16) & IOCPARM_MASK) 55 /** @def IOCBASECMD(x) the base command encoded in the ioctl value */ 56 #define IOCBASECMD(x) ((x) & ~(IOCPARM_MASK << 16)) 57 /** @def IOCGROUP(x) which group of ioctl() commands does this belong to? */ 58 #define IOCGROUP(x) (((x) >> 8) & 0xff) 59 /** @def IOCPARM_MAX Maximum size of parameter that can be passed (20 bytes) */ 60 #define IOCPARM_MAX 20 61 62 /** 63 * @defgroup IOCTL_createmacros macro's to create ioctl() values 64 * @brief these macro's should be used to create new ioctl() values 65 * @ingroup IOCTL_common 66 * @{ 67 */ 68 /** @def _IOC(inout, group, num , len) create a new ioctl */ 69 #define _IOC(inout, group, num, len) \ 70 (inout | ((len & IOCPARM_MASK)<<16) | ((group) << 8) | (num)) 71 /** @def _IO(g,n) create a new void ioctl for group g, number n */ 72 #define _IO(g,n) _IOC(IOC_VOID, (g), (n), 0) 73 /** @def _IOR(g,n,t) create a ioctl() that reads a value of type t*/ 74 #define _IOR(g,n,t) _IOC(IOC_OUT, (g), (n), sizeof(t)) 75 /** @def _IOW(g,n,t) ioctl() that writes value of type t, group g, number n */ 76 #define _IOW(g,n,t) _IOC(IOC_IN , (g), (n), sizeof(t)) 77 /** @def _IOWR(g,n,t) ioctl() that reads/writes value of type t 78 * @note this isn't _IORW as this causes name conflicts on some systems */ 79 #define _IOWR(g,n,t) _IOC(IOC_INOUT, (g), (n), sizeof(t)) 80 /** @} */ 81 82 /** @} */ 83 84 85 #endif 86 87 88 #endif /* _SYS_IOCCOM_H */ 89