diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sh/boards/dreamcast/rtc.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/sh/boards/dreamcast/rtc.c')
-rw-r--r-- | arch/sh/boards/dreamcast/rtc.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/sh/boards/dreamcast/rtc.c b/arch/sh/boards/dreamcast/rtc.c new file mode 100644 index 000000000000..379de1629134 --- /dev/null +++ b/arch/sh/boards/dreamcast/rtc.c | |||
@@ -0,0 +1,81 @@ | |||
1 | /* arch/sh/kernel/rtc-aica.c | ||
2 | * | ||
3 | * Dreamcast AICA RTC routines. | ||
4 | * | ||
5 | * Copyright (c) 2001, 2002 M. R. Brown <mrbrown@0xd6.org> | ||
6 | * Copyright (c) 2002 Paul Mundt <lethal@chaoticdreams.org> | ||
7 | * | ||
8 | * Released under the terms of the GNU GPL v2.0. | ||
9 | * | ||
10 | */ | ||
11 | |||
12 | #include <linux/time.h> | ||
13 | |||
14 | #include <asm/io.h> | ||
15 | |||
16 | extern void (*rtc_get_time)(struct timespec *); | ||
17 | extern int (*rtc_set_time)(const time_t); | ||
18 | |||
19 | /* The AICA RTC has an Epoch of 1/1/1950, so we must subtract 20 years (in | ||
20 | seconds to get the standard Unix Epoch when getting the time, and add 20 | ||
21 | years when setting the time. */ | ||
22 | #define TWENTY_YEARS ((20 * 365LU + 5) * 86400) | ||
23 | |||
24 | /* The AICA RTC is represented by a 32-bit seconds counter stored in 2 16-bit | ||
25 | registers.*/ | ||
26 | #define AICA_RTC_SECS_H 0xa0710000 | ||
27 | #define AICA_RTC_SECS_L 0xa0710004 | ||
28 | |||
29 | /** | ||
30 | * aica_rtc_gettimeofday - Get the time from the AICA RTC | ||
31 | * @ts: pointer to resulting timespec | ||
32 | * | ||
33 | * Grabs the current RTC seconds counter and adjusts it to the Unix Epoch. | ||
34 | */ | ||
35 | void aica_rtc_gettimeofday(struct timespec *ts) { | ||
36 | unsigned long val1, val2; | ||
37 | |||
38 | do { | ||
39 | val1 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) | | ||
40 | (ctrl_inl(AICA_RTC_SECS_L) & 0xffff); | ||
41 | |||
42 | val2 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) | | ||
43 | (ctrl_inl(AICA_RTC_SECS_L) & 0xffff); | ||
44 | } while (val1 != val2); | ||
45 | |||
46 | ts->tv_sec = val1 - TWENTY_YEARS; | ||
47 | |||
48 | /* Can't get nanoseconds with just a seconds counter. */ | ||
49 | ts->tv_nsec = 0; | ||
50 | } | ||
51 | |||
52 | /** | ||
53 | * aica_rtc_settimeofday - Set the AICA RTC to the current time | ||
54 | * @secs: contains the time_t to set | ||
55 | * | ||
56 | * Adjusts the given @tv to the AICA Epoch and sets the RTC seconds counter. | ||
57 | */ | ||
58 | int aica_rtc_settimeofday(const time_t secs) { | ||
59 | unsigned long val1, val2; | ||
60 | unsigned long adj = secs + TWENTY_YEARS; | ||
61 | |||
62 | do { | ||
63 | ctrl_outl((adj & 0xffff0000) >> 16, AICA_RTC_SECS_H); | ||
64 | ctrl_outl((adj & 0xffff), AICA_RTC_SECS_L); | ||
65 | |||
66 | val1 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) | | ||
67 | (ctrl_inl(AICA_RTC_SECS_L) & 0xffff); | ||
68 | |||
69 | val2 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) | | ||
70 | (ctrl_inl(AICA_RTC_SECS_L) & 0xffff); | ||
71 | } while (val1 != val2); | ||
72 | |||
73 | return 0; | ||
74 | } | ||
75 | |||
76 | void aica_time_init(void) | ||
77 | { | ||
78 | rtc_get_time = aica_rtc_gettimeofday; | ||
79 | rtc_set_time = aica_rtc_settimeofday; | ||
80 | } | ||
81 | |||