From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-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! --- arch/sh/boards/dreamcast/rtc.c | 81 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 arch/sh/boards/dreamcast/rtc.c (limited to 'arch/sh/boards/dreamcast/rtc.c') diff --git a/arch/sh/boards/dreamcast/rtc.c b/arch/sh/boards/dreamcast/rtc.c new file mode 100644 index 00000000000..379de162913 --- /dev/null +++ b/arch/sh/boards/dreamcast/rtc.c @@ -0,0 +1,81 @@ +/* arch/sh/kernel/rtc-aica.c + * + * Dreamcast AICA RTC routines. + * + * Copyright (c) 2001, 2002 M. R. Brown + * Copyright (c) 2002 Paul Mundt + * + * Released under the terms of the GNU GPL v2.0. + * + */ + +#include + +#include + +extern void (*rtc_get_time)(struct timespec *); +extern int (*rtc_set_time)(const time_t); + +/* The AICA RTC has an Epoch of 1/1/1950, so we must subtract 20 years (in + seconds to get the standard Unix Epoch when getting the time, and add 20 + years when setting the time. */ +#define TWENTY_YEARS ((20 * 365LU + 5) * 86400) + +/* The AICA RTC is represented by a 32-bit seconds counter stored in 2 16-bit + registers.*/ +#define AICA_RTC_SECS_H 0xa0710000 +#define AICA_RTC_SECS_L 0xa0710004 + +/** + * aica_rtc_gettimeofday - Get the time from the AICA RTC + * @ts: pointer to resulting timespec + * + * Grabs the current RTC seconds counter and adjusts it to the Unix Epoch. + */ +void aica_rtc_gettimeofday(struct timespec *ts) { + unsigned long val1, val2; + + do { + val1 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) | + (ctrl_inl(AICA_RTC_SECS_L) & 0xffff); + + val2 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) | + (ctrl_inl(AICA_RTC_SECS_L) & 0xffff); + } while (val1 != val2); + + ts->tv_sec = val1 - TWENTY_YEARS; + + /* Can't get nanoseconds with just a seconds counter. */ + ts->tv_nsec = 0; +} + +/** + * aica_rtc_settimeofday - Set the AICA RTC to the current time + * @secs: contains the time_t to set + * + * Adjusts the given @tv to the AICA Epoch and sets the RTC seconds counter. + */ +int aica_rtc_settimeofday(const time_t secs) { + unsigned long val1, val2; + unsigned long adj = secs + TWENTY_YEARS; + + do { + ctrl_outl((adj & 0xffff0000) >> 16, AICA_RTC_SECS_H); + ctrl_outl((adj & 0xffff), AICA_RTC_SECS_L); + + val1 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) | + (ctrl_inl(AICA_RTC_SECS_L) & 0xffff); + + val2 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) | + (ctrl_inl(AICA_RTC_SECS_L) & 0xffff); + } while (val1 != val2); + + return 0; +} + +void aica_time_init(void) +{ + rtc_get_time = aica_rtc_gettimeofday; + rtc_set_time = aica_rtc_settimeofday; +} + -- cgit v1.2.3