xref: /openbmc/linux/arch/sh/include/asm/watchdog.h (revision b737eecd)
1 /* SPDX-License-Identifier: GPL-2.0+
2  *
3  * include/asm-sh/watchdog.h
4  *
5  * Copyright (C) 2002, 2003 Paul Mundt
6  * Copyright (C) 2009 Siemens AG
7  * Copyright (C) 2009 Valentin Sitdikov
8  */
9 #ifndef __ASM_SH_WATCHDOG_H
10 #define __ASM_SH_WATCHDOG_H
11 
12 #include <linux/types.h>
13 #include <linux/io.h>
14 
15 #define WTCNT_HIGH	0x5a
16 #define WTCSR_HIGH	0xa5
17 
18 #define WTCSR_CKS2	0x04
19 #define WTCSR_CKS1	0x02
20 #define WTCSR_CKS0	0x01
21 
22 #include <cpu/watchdog.h>
23 
24 /*
25  * See cpu-sh2/watchdog.h for explanation of this stupidity..
26  */
27 #ifndef WTCNT_R
28 #  define WTCNT_R	WTCNT
29 #endif
30 
31 #ifndef WTCSR_R
32 #  define WTCSR_R	WTCSR
33 #endif
34 
35 /*
36  * CKS0-2 supports a number of clock division ratios. At the time the watchdog
37  * is enabled, it defaults to a 41 usec overflow period .. we overload this to
38  * something a little more reasonable, and really can't deal with anything
39  * lower than WTCSR_CKS_1024, else we drop back into the usec range.
40  *
41  * Clock Division Ratio         Overflow Period
42  * --------------------------------------------
43  *     1/32 (initial value)       41 usecs
44  *     1/64                       82 usecs
45  *     1/128                     164 usecs
46  *     1/256                     328 usecs
47  *     1/512                     656 usecs
48  *     1/1024                   1.31 msecs
49  *     1/2048                   2.62 msecs
50  *     1/4096                   5.25 msecs
51  */
52 #define WTCSR_CKS_32	0x00
53 #define WTCSR_CKS_64	0x01
54 #define WTCSR_CKS_128	0x02
55 #define WTCSR_CKS_256	0x03
56 #define WTCSR_CKS_512	0x04
57 #define WTCSR_CKS_1024	0x05
58 #define WTCSR_CKS_2048	0x06
59 #define WTCSR_CKS_4096	0x07
60 
61 #if defined(CONFIG_CPU_SUBTYPE_SH7785) || defined(CONFIG_CPU_SUBTYPE_SH7780)
62 /**
63  * 	sh_wdt_read_cnt - Read from Counter
64  * 	Reads back the WTCNT value.
65  */
66 static inline __u32 sh_wdt_read_cnt(void)
67 {
68 	return __raw_readl(WTCNT_R);
69 }
70 
71 /**
72  *	sh_wdt_write_cnt - Write to Counter
73  *	@val: Value to write
74  *
75  *	Writes the given value @val to the lower byte of the timer counter.
76  *	The upper byte is set manually on each write.
77  */
78 static inline void sh_wdt_write_cnt(__u32 val)
79 {
80 	__raw_writel((WTCNT_HIGH << 24) | (__u32)val, WTCNT);
81 }
82 
83 /**
84  *	sh_wdt_write_bst - Write to Counter
85  *	@val: Value to write
86  *
87  *	Writes the given value @val to the lower byte of the timer counter.
88  *	The upper byte is set manually on each write.
89  */
90 static inline void sh_wdt_write_bst(__u32 val)
91 {
92 	__raw_writel((WTBST_HIGH << 24) | (__u32)val, WTBST);
93 }
94 /**
95  * 	sh_wdt_read_csr - Read from Control/Status Register
96  *
97  *	Reads back the WTCSR value.
98  */
99 static inline __u32 sh_wdt_read_csr(void)
100 {
101 	return __raw_readl(WTCSR_R);
102 }
103 
104 /**
105  * 	sh_wdt_write_csr - Write to Control/Status Register
106  * 	@val: Value to write
107  *
108  * 	Writes the given value @val to the lower byte of the control/status
109  * 	register. The upper byte is set manually on each write.
110  */
111 static inline void sh_wdt_write_csr(__u32 val)
112 {
113 	__raw_writel((WTCSR_HIGH << 24) | (__u32)val, WTCSR);
114 }
115 #else
116 /**
117  * 	sh_wdt_read_cnt - Read from Counter
118  * 	Reads back the WTCNT value.
119  */
120 static inline __u8 sh_wdt_read_cnt(void)
121 {
122 	return __raw_readb(WTCNT_R);
123 }
124 
125 /**
126  *	sh_wdt_write_cnt - Write to Counter
127  *	@val: Value to write
128  *
129  *	Writes the given value @val to the lower byte of the timer counter.
130  *	The upper byte is set manually on each write.
131  */
132 static inline void sh_wdt_write_cnt(__u8 val)
133 {
134 	__raw_writew((WTCNT_HIGH << 8) | (__u16)val, WTCNT);
135 }
136 
137 /**
138  * 	sh_wdt_read_csr - Read from Control/Status Register
139  *
140  *	Reads back the WTCSR value.
141  */
142 static inline __u8 sh_wdt_read_csr(void)
143 {
144 	return __raw_readb(WTCSR_R);
145 }
146 
147 /**
148  * 	sh_wdt_write_csr - Write to Control/Status Register
149  * 	@val: Value to write
150  *
151  * 	Writes the given value @val to the lower byte of the control/status
152  * 	register. The upper byte is set manually on each write.
153  */
154 static inline void sh_wdt_write_csr(__u8 val)
155 {
156 	__raw_writew((WTCSR_HIGH << 8) | (__u16)val, WTCSR);
157 }
158 #endif /* CONFIG_CPU_SUBTYPE_SH7785 || CONFIG_CPU_SUBTYPE_SH7780 */
159 #endif /* __ASM_SH_WATCHDOG_H */
160