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 #include <features.h> 10 11 #ifdef _DEFAULT_SOURCE 12 13 14 /** 15 * @defgroup IOCTL_common sys/ioccom.h 16 * @brief Definitions & maros common to ioctl() 17 * @ingroup OpenBeOS_POSIX 18 * @ingroup IOCTL 19 * Ioctl values passed as the command (2nd) variable have the 20 * command encoded in the lower word and the size of any parameters 21 * in the upper word (in or out). 22 * The high 3 bits are used to encode whether it's in or out. 23 * Due to this you can't just give an ioctl value, you need to encode 24 * it using macros described in 25 * @ref IOCTL_macros 26 * @{ 27 */ 28 29 /** @defgroup IOCTL_parm ioctl() parameter definitions 30 * @ingroup IOCTL_common 31 * @{ 32 */ 33 /** @def IOC_VOID */ 34 #define IOC_VOID (ulong)0x20000000 35 /** @def IOC_OUT ioctl expects data (output) */ 36 #define IOC_OUT (ulong)0x40000000 37 /** @def IOC_IN ioctl passes a value in */ 38 #define IOC_IN (ulong)0x80000000 39 /** @def IOC_INOUT ioctl passes data in and out */ 40 #define IOC_INOUT (IOC_IN|IOC_OUT) 41 /** @def IOC_DIRMASK */ 42 #define IOC_DIRMASK (ulong)0xe0000000 43 /** @} */ 44 45 /** 46 * @defgroup IOCTL_macros IOCTL macros 47 * These should be used to define the values passed in as cmd to 48 * ioctl() 49 * @ingroup IOCTL_common 50 * @{ 51 */ 52 /** @def IOCPARM_MASK mask used to for following macros */ 53 #define IOCPARM_MASK 0x1fff 54 /** @def IOCPARM_LEN(x) length of the data passed as param */ 55 #define IOCPARM_LEN(x) (((x) >> 16) & IOCPARM_MASK) 56 /** @def IOCBASECMD(x) the base command encoded in the ioctl value */ 57 #define IOCBASECMD(x) ((x) & ~(IOCPARM_MASK << 16)) 58 /** @def IOCGROUP(x) which group of ioctl() commands does this belong to? */ 59 #define IOCGROUP(x) (((x) >> 8) & 0xff) 60 /** @def IOCPARM_MAX Maximum size of parameter that can be passed (20 bytes) */ 61 #define IOCPARM_MAX 20 62 63 /** 64 * @defgroup IOCTL_createmacros macro's to create ioctl() values 65 * @brief these macro's should be used to create new ioctl() values 66 * @ingroup IOCTL_common 67 * @{ 68 */ 69 /** @def _IOC(inout, group, num , len) create a new ioctl */ 70 #define _IOC(inout, group, num, len) \ 71 (inout | ((len & IOCPARM_MASK)<<16) | ((group) << 8) | (num)) 72 /** @def _IO(g,n) create a new void ioctl for group g, number n */ 73 #define _IO(g,n) _IOC(IOC_VOID, (g), (n), 0) 74 /** @def _IOR(g,n,t) create a ioctl() that reads a value of type t*/ 75 #define _IOR(g,n,t) _IOC(IOC_OUT, (g), (n), sizeof(t)) 76 /** @def _IOW(g,n,t) ioctl() that writes value of type t, group g, number n */ 77 #define _IOW(g,n,t) _IOC(IOC_IN , (g), (n), sizeof(t)) 78 /** @def _IOWR(g,n,t) ioctl() that reads/writes value of type t 79 * @note this isn't _IORW as this causes name conflicts on some systems */ 80 #define _IOWR(g,n,t) _IOC(IOC_INOUT, (g), (n), sizeof(t)) 81 /** @} */ 82 83 /** @} */ 84 85 86 #endif 87 88 89 #endif /* _SYS_IOCCOM_H */ 90