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