xref: /openbmc/linux/arch/sh/include/asm/watchdog.h (revision 9cfc5c90)
1 /*
2  * include/asm-sh/watchdog.h
3  *
4  * Copyright (C) 2002, 2003 Paul Mundt
5  * Copyright (C) 2009 Siemens AG
6  * Copyright (C) 2009 Valentin Sitdikov
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the
10  * Free Software Foundation; either version 2 of the License, or (at your
11  * option) any later version.
12  */
13 #ifndef __ASM_SH_WATCHDOG_H
14 #define __ASM_SH_WATCHDOG_H
15 #ifdef __KERNEL__
16 
17 #include <linux/types.h>
18 #include <linux/io.h>
19 
20 #define WTCNT_HIGH	0x5a
21 #define WTCSR_HIGH	0xa5
22 
23 #define WTCSR_CKS2	0x04
24 #define WTCSR_CKS1	0x02
25 #define WTCSR_CKS0	0x01
26 
27 #include <cpu/watchdog.h>
28 
29 /*
30  * See cpu-sh2/watchdog.h for explanation of this stupidity..
31  */
32 #ifndef WTCNT_R
33 #  define WTCNT_R	WTCNT
34 #endif
35 
36 #ifndef WTCSR_R
37 #  define WTCSR_R	WTCSR
38 #endif
39 
40 /*
41  * CKS0-2 supports a number of clock division ratios. At the time the watchdog
42  * is enabled, it defaults to a 41 usec overflow period .. we overload this to
43  * something a little more reasonable, and really can't deal with anything
44  * lower than WTCSR_CKS_1024, else we drop back into the usec range.
45  *
46  * Clock Division Ratio         Overflow Period
47  * --------------------------------------------
48  *     1/32 (initial value)       41 usecs
49  *     1/64                       82 usecs
50  *     1/128                     164 usecs
51  *     1/256                     328 usecs
52  *     1/512                     656 usecs
53  *     1/1024                   1.31 msecs
54  *     1/2048                   2.62 msecs
55  *     1/4096                   5.25 msecs
56  */
57 #define WTCSR_CKS_32	0x00
58 #define WTCSR_CKS_64	0x01
59 #define WTCSR_CKS_128	0x02
60 #define WTCSR_CKS_256	0x03
61 #define WTCSR_CKS_512	0x04
62 #define WTCSR_CKS_1024	0x05
63 #define WTCSR_CKS_2048	0x06
64 #define WTCSR_CKS_4096	0x07
65 
66 #if defined(CONFIG_CPU_SUBTYPE_SH7785) || defined(CONFIG_CPU_SUBTYPE_SH7780)
67 /**
68  * 	sh_wdt_read_cnt - Read from Counter
69  * 	Reads back the WTCNT value.
70  */
71 static inline __u32 sh_wdt_read_cnt(void)
72 {
73 	return __raw_readl(WTCNT_R);
74 }
75 
76 /**
77  *	sh_wdt_write_cnt - Write to Counter
78  *	@val: Value to write
79  *
80  *	Writes the given value @val to the lower byte of the timer counter.
81  *	The upper byte is set manually on each write.
82  */
83 static inline void sh_wdt_write_cnt(__u32 val)
84 {
85 	__raw_writel((WTCNT_HIGH << 24) | (__u32)val, WTCNT);
86 }
87 
88 /**
89  *	sh_wdt_write_bst - Write to Counter
90  *	@val: Value to write
91  *
92  *	Writes the given value @val to the lower byte of the timer counter.
93  *	The upper byte is set manually on each write.
94  */
95 static inline void sh_wdt_write_bst(__u32 val)
96 {
97 	__raw_writel((WTBST_HIGH << 24) | (__u32)val, WTBST);
98 }
99 /**
100  * 	sh_wdt_read_csr - Read from Control/Status Register
101  *
102  *	Reads back the WTCSR value.
103  */
104 static inline __u32 sh_wdt_read_csr(void)
105 {
106 	return __raw_readl(WTCSR_R);
107 }
108 
109 /**
110  * 	sh_wdt_write_csr - Write to Control/Status Register
111  * 	@val: Value to write
112  *
113  * 	Writes the given value @val to the lower byte of the control/status
114  * 	register. The upper byte is set manually on each write.
115  */
116 static inline void sh_wdt_write_csr(__u32 val)
117 {
118 	__raw_writel((WTCSR_HIGH << 24) | (__u32)val, WTCSR);
119 }
120 #else
121 /**
122  * 	sh_wdt_read_cnt - Read from Counter
123  * 	Reads back the WTCNT value.
124  */
125 static inline __u8 sh_wdt_read_cnt(void)
126 {
127 	return __raw_readb(WTCNT_R);
128 }
129 
130 /**
131  *	sh_wdt_write_cnt - Write to Counter
132  *	@val: Value to write
133  *
134  *	Writes the given value @val to the lower byte of the timer counter.
135  *	The upper byte is set manually on each write.
136  */
137 static inline void sh_wdt_write_cnt(__u8 val)
138 {
139 	__raw_writew((WTCNT_HIGH << 8) | (__u16)val, WTCNT);
140 }
141 
142 /**
143  * 	sh_wdt_read_csr - Read from Control/Status Register
144  *
145  *	Reads back the WTCSR value.
146  */
147 static inline __u8 sh_wdt_read_csr(void)
148 {
149 	return __raw_readb(WTCSR_R);
150 }
151 
152 /**
153  * 	sh_wdt_write_csr - Write to Control/Status Register
154  * 	@val: Value to write
155  *
156  * 	Writes the given value @val to the lower byte of the control/status
157  * 	register. The upper byte is set manually on each write.
158  */
159 static inline void sh_wdt_write_csr(__u8 val)
160 {
161 	__raw_writew((WTCSR_HIGH << 8) | (__u16)val, WTCSR);
162 }
163 #endif /* CONFIG_CPU_SUBTYPE_SH7785 || CONFIG_CPU_SUBTYPE_SH7780 */
164 #endif /* __KERNEL__ */
165 #endif /* __ASM_SH_WATCHDOG_H */
166