xref: /openbmc/linux/arch/sh/include/asm/watchdog.h (revision b8265621)
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 #ifdef __KERNEL__
12 
13 #include <linux/types.h>
14 #include <linux/io.h>
15 
16 #define WTCNT_HIGH	0x5a
17 #define WTCSR_HIGH	0xa5
18 
19 #define WTCSR_CKS2	0x04
20 #define WTCSR_CKS1	0x02
21 #define WTCSR_CKS0	0x01
22 
23 #include <cpu/watchdog.h>
24 
25 /*
26  * See cpu-sh2/watchdog.h for explanation of this stupidity..
27  */
28 #ifndef WTCNT_R
29 #  define WTCNT_R	WTCNT
30 #endif
31 
32 #ifndef WTCSR_R
33 #  define WTCSR_R	WTCSR
34 #endif
35 
36 /*
37  * CKS0-2 supports a number of clock division ratios. At the time the watchdog
38  * is enabled, it defaults to a 41 usec overflow period .. we overload this to
39  * something a little more reasonable, and really can't deal with anything
40  * lower than WTCSR_CKS_1024, else we drop back into the usec range.
41  *
42  * Clock Division Ratio         Overflow Period
43  * --------------------------------------------
44  *     1/32 (initial value)       41 usecs
45  *     1/64                       82 usecs
46  *     1/128                     164 usecs
47  *     1/256                     328 usecs
48  *     1/512                     656 usecs
49  *     1/1024                   1.31 msecs
50  *     1/2048                   2.62 msecs
51  *     1/4096                   5.25 msecs
52  */
53 #define WTCSR_CKS_32	0x00
54 #define WTCSR_CKS_64	0x01
55 #define WTCSR_CKS_128	0x02
56 #define WTCSR_CKS_256	0x03
57 #define WTCSR_CKS_512	0x04
58 #define WTCSR_CKS_1024	0x05
59 #define WTCSR_CKS_2048	0x06
60 #define WTCSR_CKS_4096	0x07
61 
62 #if defined(CONFIG_CPU_SUBTYPE_SH7785) || defined(CONFIG_CPU_SUBTYPE_SH7780)
63 /**
64  * 	sh_wdt_read_cnt - Read from Counter
65  * 	Reads back the WTCNT value.
66  */
67 static inline __u32 sh_wdt_read_cnt(void)
68 {
69 	return __raw_readl(WTCNT_R);
70 }
71 
72 /**
73  *	sh_wdt_write_cnt - Write to Counter
74  *	@val: Value to write
75  *
76  *	Writes the given value @val to the lower byte of the timer counter.
77  *	The upper byte is set manually on each write.
78  */
79 static inline void sh_wdt_write_cnt(__u32 val)
80 {
81 	__raw_writel((WTCNT_HIGH << 24) | (__u32)val, WTCNT);
82 }
83 
84 /**
85  *	sh_wdt_write_bst - Write to Counter
86  *	@val: Value to write
87  *
88  *	Writes the given value @val to the lower byte of the timer counter.
89  *	The upper byte is set manually on each write.
90  */
91 static inline void sh_wdt_write_bst(__u32 val)
92 {
93 	__raw_writel((WTBST_HIGH << 24) | (__u32)val, WTBST);
94 }
95 /**
96  * 	sh_wdt_read_csr - Read from Control/Status Register
97  *
98  *	Reads back the WTCSR value.
99  */
100 static inline __u32 sh_wdt_read_csr(void)
101 {
102 	return __raw_readl(WTCSR_R);
103 }
104 
105 /**
106  * 	sh_wdt_write_csr - Write to Control/Status Register
107  * 	@val: Value to write
108  *
109  * 	Writes the given value @val to the lower byte of the control/status
110  * 	register. The upper byte is set manually on each write.
111  */
112 static inline void sh_wdt_write_csr(__u32 val)
113 {
114 	__raw_writel((WTCSR_HIGH << 24) | (__u32)val, WTCSR);
115 }
116 #else
117 /**
118  * 	sh_wdt_read_cnt - Read from Counter
119  * 	Reads back the WTCNT value.
120  */
121 static inline __u8 sh_wdt_read_cnt(void)
122 {
123 	return __raw_readb(WTCNT_R);
124 }
125 
126 /**
127  *	sh_wdt_write_cnt - Write to Counter
128  *	@val: Value to write
129  *
130  *	Writes the given value @val to the lower byte of the timer counter.
131  *	The upper byte is set manually on each write.
132  */
133 static inline void sh_wdt_write_cnt(__u8 val)
134 {
135 	__raw_writew((WTCNT_HIGH << 8) | (__u16)val, WTCNT);
136 }
137 
138 /**
139  * 	sh_wdt_read_csr - Read from Control/Status Register
140  *
141  *	Reads back the WTCSR value.
142  */
143 static inline __u8 sh_wdt_read_csr(void)
144 {
145 	return __raw_readb(WTCSR_R);
146 }
147 
148 /**
149  * 	sh_wdt_write_csr - Write to Control/Status Register
150  * 	@val: Value to write
151  *
152  * 	Writes the given value @val to the lower byte of the control/status
153  * 	register. The upper byte is set manually on each write.
154  */
155 static inline void sh_wdt_write_csr(__u8 val)
156 {
157 	__raw_writew((WTCSR_HIGH << 8) | (__u16)val, WTCSR);
158 }
159 #endif /* CONFIG_CPU_SUBTYPE_SH7785 || CONFIG_CPU_SUBTYPE_SH7780 */
160 #endif /* __KERNEL__ */
161 #endif /* __ASM_SH_WATCHDOG_H */
162