clocksource: arch_timer: Make register accessors less error-prone
[firefly-linux-kernel-4.4.55.git] / include / clocksource / arm_arch_timer.h
1 /*
2  * Copyright (C) 2012 ARM Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 #ifndef __CLKSOURCE_ARM_ARCH_TIMER_H
17 #define __CLKSOURCE_ARM_ARCH_TIMER_H
18
19 #include <linux/clocksource.h>
20 #include <linux/types.h>
21
22 #define ARCH_TIMER_CTRL_ENABLE          (1 << 0)
23 #define ARCH_TIMER_CTRL_IT_MASK         (1 << 1)
24 #define ARCH_TIMER_CTRL_IT_STAT         (1 << 2)
25
26 enum arch_timer_reg {
27         ARCH_TIMER_REG_CTRL,
28         ARCH_TIMER_REG_TVAL,
29 };
30
31 #define ARCH_TIMER_PHYS_ACCESS          0
32 #define ARCH_TIMER_VIRT_ACCESS          1
33
34 #ifdef CONFIG_ARM_ARCH_TIMER
35
36 extern u32 arch_timer_get_rate(void);
37 extern u64 (*arch_timer_read_counter)(void);
38 extern struct timecounter *arch_timer_get_timecounter(void);
39
40 #else
41
42 static inline u32 arch_timer_get_rate(void)
43 {
44         return 0;
45 }
46
47 static inline u64 arch_timer_read_counter(void)
48 {
49         return 0;
50 }
51
52 static inline struct timecounter *arch_timer_get_timecounter(void)
53 {
54         return NULL;
55 }
56
57 #endif
58
59 #endif