blob: b85a9495c2dbeb71e1315e28bc5995bb9d6664de (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
//go:build nxp && mk66f18
// +build nxp,mk66f18
package volatile
import "unsafe"
const registerBase = 0x40000000
const registerEnd = 0x40100000
const bitbandBase = 0x42000000
//go:inline
func bitbandAddress(reg uintptr, bit uint8) uintptr {
if uintptr(bit) > 32 {
panic("invalid bit position")
}
if reg < registerBase || reg >= registerEnd {
panic("register is out of range")
}
return (reg-registerBase)*32 + uintptr(bit)*4 + bitbandBase
}
// Special types that causes loads/stores to be volatile (necessary for
// memory-mapped registers).
type BitRegister struct {
Reg uint32
}
// Get returns the of the mapped register bit. It is the volatile equivalent of:
//
// *r.Reg
//
//go:inline
func (r *BitRegister) Get() bool {
return LoadUint32(&r.Reg) != 0
}
// Set sets the mapped register bit. It is the volatile equivalent of:
//
// *r.Reg = 1
//
//go:inline
func (r *BitRegister) Set(v bool) {
var i uint32
if v {
i = 1
}
StoreUint32(&r.Reg, i)
}
// Bit maps bit N of register R to the corresponding bitband address. Bit panics
// if R is not an AIPS or GPIO register or if N is out of range (greater than
// the number of bits in a register minus one).
//
// go:inline
func (r *Register8) Bit(bit uint8) *BitRegister {
ptr := bitbandAddress(uintptr(unsafe.Pointer(&r.Reg)), bit)
return (*BitRegister)(unsafe.Pointer(ptr))
}
// Bit maps bit N of register R to the corresponding bitband address. Bit panics
// if R is not an AIPS or GPIO register or if N is out of range (greater than
// the number of bits in a register minus one).
//
// go:inline
func (r *Register16) Bit(bit uint8) *BitRegister {
ptr := bitbandAddress(uintptr(unsafe.Pointer(&r.Reg)), bit)
return (*BitRegister)(unsafe.Pointer(ptr))
}
// Bit maps bit N of register R to the corresponding bitband address. Bit panics
// if R is not an AIPS or GPIO register or if N is out of range (greater than
// the number of bits in a register minus one).
//
// go:inline
func (r *Register32) Bit(bit uint8) *BitRegister {
ptr := bitbandAddress(uintptr(unsafe.Pointer(&r.Reg)), bit)
return (*BitRegister)(unsafe.Pointer(ptr))
}
|
