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
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
/*
* Copyright (c) 2011 The Chromium OS Authors.
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#ifndef __TEGRA2_BITFIELD_H
#define __TEGRA2_BITFIELD_H
/*
* Macros for working with bit fields. To use these, set things up like this:
*
* #define UART_PA_START 0x67000000 Physical address of UART
* #define UART_FBCON_RANGE 5:3 Bit range for the FBCON field
* enum { An enum with allowed values
* UART_FBCON_OFF,
* UART_FBCON_ON,
* UART_FBCON_MULTI,
* UART_FBCON_SLAVE,
* };
* struct uart_ctlr *uart = (struct uart_ctlr *)UART_PA_START;
*
* This defines a bit field of 3 bits starting at bit 5 and extending down
* to bit 3, i.e. 5:3
*
* Then:
* bf_unpack(UART_FBCON)
* - return the value of bits 5:3 (shifted down to bits 2:0)
*
* bf_pack(UART_FBCON, 4)
* - return a word with that field set to 4 (so in this case (4 << 3))
*
* bf_update(UART_FBCON, word, val)
* - update a field within word so that its value is val.
*
* bf_enum_writel(UART_FBCON, MULTI, &uart->fbcon)
* - set the UART's FBCON field to MULTI
*
*
* Why have bitfield macros?
* 1. Reability
* 2. Maintainability
* 3. Less error prone
*
* For example, this:
*
* int RegVal = 0;
* RegVal= readl(UsbBase+USB_SUSP_CTRL);
* RegVal |= Bit11;
* writel(RegVal, UsbBase+USB_SUSP_CTRL);
* if(UsbBase == NV_ADDRESS_MAP_USB3_BASE)
* {
* RegVal = readl(UsbBase+USB_SUSP_CTRL);
* RegVal |= Bit12;
* writel(RegVal, UsbBase+USB_SUSP_CTRL);
* }
*
* becomes this:
*
* bitfield_writel(UTMIP_RESET, 1, &usbctlr->susp_ctrl);
* if (id == PERIPH_ID_USB3)
* bitfield_writel(UTMIP_PHY_ENB, 1, &usbctlr->susp_ctrl);
*/
/* Returns the low bit of the bitfield */
#define BITFIELD_LOWBIT(range) ((0 ? range) & 0x1f)
/* Returns the high bit of the bitfield */
#define BITFIELD_HIGHBIT(range) (1 ? range)
/* Returns the width of the bitfield (in bits) */
#define BITFIELD_WIDTH(range) \
(BITFIELD_HIGHBIT(range) - BITFIELD_LOWBIT(range) + 1)
/*
* Returns the number of bits the bitfield needs to be shifted left to pack it.
* This is just the same as the low bit.
*/
#define bf_shift(field) BITFIELD_LOWBIT(field ## _RANGE)
/* Returns the unshifted mask for the field (i.e. LSB of mask is bit 0) */
#define bf_rawmask(field) (0xfffffffful >> \
(32 - BITFIELD_WIDTH(field ## _RANGE)))
/* Returns the mask for a field. Clear these bits to zero the field */
#define bf_mask(field) \
(bf_rawmask(field) << (bf_shift(field)))
/* Unpacks and returns a value extracted from a field */
#define bf_unpack(field, word) \
(((unsigned)(word) >> bf_shift(field)) & bf_rawmask(field))
/*
* Packs a value into a field - this masks the value to ensure it does not
* overflow into another field.
*/
#define bf_pack(field, value) \
((((unsigned)(value)) & bf_rawmask(field)) \
<< bf_shift(field))
/* Sets the value of a field in a word to the given value */
#define bf_update(field, word, value) \
((word) = ((word) & ~bf_mask(field)) | \
bf_pack(field, value))
/*
* Sets the value of a field in a register to the given value using
* readl/writel
*/
#define bf_writel(field, value, reg) ({ \
u32 *__reg = (u32 *)(reg); \
u32 __oldval = readl(__reg); \
bf_update(field, __oldval, value); \
writel(__oldval, __reg); \
})
/* Unpacks a field from a register using readl */
#define bf_readl(field, reg) \
bf_unpack(field, readl(reg))
/*
* Clears a field in a register using writel - like
* bf_writel(field, 0, reg)
*/
#define bf_clearl(field, reg) bf_writel(field, 0, reg)
/*
* Sets the value of a field in a register to the given enum.
*
* The enum should have the field as a prefix.
*/
#define bf_enum(field, _enum) bf_pack(field, field ## _ ## _enum)
/*
* Sets the value of a field in a register to the given enum.
*
* The enum should have the field as a prefix.
*/
#define bf_enum_writel(field, _enum, reg) \
bf_writel(field, field ## _ ## _enum, reg)
/*
* Return a word with the bitfield set to all ones.
*/
#define bf_ones(field) bf_mask(field)
#endif
|
