xref: /minix/minix/include/minix/devio.h (revision 83133719)
1 /* This file provides basic types and some constants for the
2  * SYS_DEVIO and SYS_VDEVIO system calls, which allow user-level
3  * processes to perform device I/O.
4  *
5  * Created:
6  *	Apr 08, 2004 by Jorrit N. Herder
7  */
8 
9 #ifndef _DEVIO_H
10 #define _DEVIO_H
11 
12 #include <minix/sys_config.h>     /* needed to include <minix/type.h> */
13 #include <sys/types.h>        /* u8_t, u16_t, u32_t needed */
14 
15 typedef u16_t port_t;
16 
17 /* We have different granularities of port I/O: 8, 16, 32 bits.
18  * Also see <ibm/portio.h>, which has functions for bytes, words,
19  * and longs. Hence, we need different (port,value)-pair types.
20  */
21 typedef struct { u16_t port;  u8_t value; } pvb_pair_t;
22 typedef struct { u16_t port; u16_t value; } pvw_pair_t;
23 typedef struct { u16_t port; u32_t value; } pvl_pair_t;
24 
25 /* Macro shorthand to set (port,value)-pair. */
26 #define pv_set(pv, p, v) do {					\
27 	u32_t _p = (p), _v = (v);				\
28 	(pv).port = _p;						\
29 	(pv).value = _v;					\
30 	if((pv).port != _p || (pv).value != _v) {		\
31 		printf("%s:%d: actual port: 0x%x != 0x%x || "	\
32 			"actual value: 0x%x != 0x%x\n",	\
33 			__FILE__, __LINE__, (pv).port, _p, (pv).value, _v); \
34 		panic("pv_set(" #pv ", " #p ", " #v ")"); \
35 	}							\
36 } while(0)
37 
38 #if 0	/* no longer in use !!! */
39 /* Define a number of flags to indicate granularity we are using. */
40 #define MASK_GRANULARITY 0x000F  /* not in use! does not match flags */
41 #define PVB_FLAG 'b'
42 #define PVW_FLAG 'w'
43 #define PVL_FLAG 'l'
44 
45 /* Flags indicating whether request wants to do input or output. */
46 #define MASK_IN_OR_OUT 0x00F0
47 #define DEVIO_INPUT 0x0010
48 #define DEVIO_OUTPUT 0x0020
49 #endif	/* 0 */
50 
51 #if 0	/* no longer used !!! */
52 /* Define how large the (port,value)-pair buffer in the kernel is.
53  * This buffer is used to copy the (port,value)-pairs in kernel space.
54  */
55 #define PV_BUF_SIZE  64      /* creates char pv_buf[PV_BUF_SIZE] */
56 
57 /* Note that SYS_VDEVIO sends a pointer to a vector of (port,value)-pairs,
58  * whereas SYS_DEVIO includes a single (port,value)-pair in the messages.
59  * Calculate maximum number of (port,value)-pairs that can be handled
60  * in a single SYS_VDEVIO system call with above struct definitions.
61  */
62 #define MAX_PVB_PAIRS ((PV_BUF_SIZE * sizeof(char)) / sizeof(pvb_pair_t))
63 #define MAX_PVW_PAIRS ((PV_BUF_SIZE * sizeof(char)) / sizeof(pvw_pair_t))
64 #define MAX_PVL_PAIRS ((PV_BUF_SIZE * sizeof(char)) / sizeof(pvl_pair_t))
65 #endif /* 0 */
66 
67 
68 #endif  /* _DEVIO_H */
69