1 /* SPDX-License-Identifier: GPL-2.0
2 *
3 * include/asm-sh/cpu-sh2/watchdog.h
4 *
5 * Copyright (C) 2002, 2003 Paul Mundt
6 */
7 #ifndef __ASM_CPU_SH2_WATCHDOG_H
8 #define __ASM_CPU_SH2_WATCHDOG_H
9
10 /*
11 * More SH-2 brilliance .. its not good enough that we can't read
12 * and write the same sizes to WTCNT, now we have to read and write
13 * with different sizes at different addresses for WTCNT _and_ RSTCSR.
14 *
15 * At least on the bright side no one has managed to screw over WTCSR
16 * in this fashion .. yet.
17 */
18 /* Register definitions */
19 #define WTCNT 0xfffffe80
20 #define WTCSR 0xfffffe80
21 #define RSTCSR 0xfffffe82
22
23 #define WTCNT_R (WTCNT + 1)
24 #define RSTCSR_R (RSTCSR + 1)
25
26 /* Bit definitions */
27 #define WTCSR_IOVF 0x80
28 #define WTCSR_WT 0x40
29 #define WTCSR_TME 0x20
30 #define WTCSR_RSTS 0x00
31
32 #define RSTCSR_RSTS 0x20
33
34 /**
35 * sh_wdt_read_rstcsr - Read from Reset Control/Status Register
36 *
37 * Reads back the RSTCSR value.
38 */
39 static inline __u8 sh_wdt_read_rstcsr(void)
40 {
41 /*
42 * Same read/write brain-damage as for WTCNT here..
43 */
44 return __raw_readb(RSTCSR_R);
45 }
46
47 /**
48 * sh_wdt_write_csr - Write to Reset Control/Status Register
49 *
50 * @val: Value to write
51 *
52 * Writes the given value @val to the lower byte of the control/status
53 * register. The upper byte is set manually on each write.
54 */
55 static inline void sh_wdt_write_rstcsr(__u8 val)
56 {
57 /*
58 * Note: Due to the brain-damaged nature of this register,
59 * we can't presently touch the WOVF bit, since the upper byte
60 * has to be swapped for this. So just leave it alone..
61 */
62 __raw_writeb((WTCNT_HIGH << 8) | (__u16)val, RSTCSR);
63 }
64
65 #endif /* __ASM_CPU_SH2_WATCHDOG_H */
66