1 /*
2  * include/asm-sh/cpu-sh2/watchdog.h
3  *
4  * Copyright (C) 2002, 2003 Paul Mundt
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 #ifndef __ASM_CPU_SH2_WATCHDOG_H
11 #define __ASM_CPU_SH2_WATCHDOG_H
12 
13 /*
14  * More SH-2 brilliance .. its not good enough that we can't read
15  * and write the same sizes to WTCNT, now we have to read and write
16  * with different sizes at different addresses for WTCNT _and_ RSTCSR.
17  *
18  * At least on the bright side no one has managed to screw over WTCSR
19  * in this fashion .. yet.
20  */
21 /* Register definitions */
22 #define WTCNT		0xfffffe80
23 #define WTCSR		0xfffffe80
24 #define RSTCSR		0xfffffe82
25 
26 #define WTCNT_R		(WTCNT + 1)
27 #define RSTCSR_R	(RSTCSR + 1)
28 
29 /* Bit definitions */
30 #define WTCSR_IOVF	0x80
31 #define WTCSR_WT	0x40
32 #define WTCSR_TME	0x20
33 #define WTCSR_RSTS	0x00
34 
35 #define RSTCSR_RSTS	0x20
36 
37 /**
38  * 	sh_wdt_read_rstcsr - Read from Reset Control/Status Register
39  *
40  *	Reads back the RSTCSR value.
41  */
sh_wdt_read_rstcsr(void)42 static inline __u8 sh_wdt_read_rstcsr(void)
43 {
44 	/*
45 	 * Same read/write brain-damage as for WTCNT here..
46 	 */
47 	return __raw_readb(RSTCSR_R);
48 }
49 
50 /**
51  * 	sh_wdt_write_csr - Write to Reset Control/Status Register
52  *
53  * 	@val: Value to write
54  *
55  * 	Writes the given value @val to the lower byte of the control/status
56  * 	register. The upper byte is set manually on each write.
57  */
sh_wdt_write_rstcsr(__u8 val)58 static inline void sh_wdt_write_rstcsr(__u8 val)
59 {
60 	/*
61 	 * Note: Due to the brain-damaged nature of this register,
62 	 * we can't presently touch the WOVF bit, since the upper byte
63 	 * has to be swapped for this. So just leave it alone..
64 	 */
65 	__raw_writeb((WTCNT_HIGH << 8) | (__u16)val, RSTCSR);
66 }
67 
68 #endif /* __ASM_CPU_SH2_WATCHDOG_H */
69 
70