rtc.c (e5451c8f8330e03ad3cfa16048b4daf961af434f) rtc.c (b0495e4b67b230cdb8a7ba244cd260e529c53b84)
1/*
2 * arch/sh/boards/dreamcast/rtc.c
3 *
4 * Dreamcast AICA RTC routines.
5 *
6 * Copyright (c) 2001, 2002 M. R. Brown <mrbrown@0xd6.org>
7 * Copyright (c) 2002 Paul Mundt <lethal@chaoticdreams.org>
8 *
9 * Released under the terms of the GNU GPL v2.0.
10 *
11 */
12
13#include <linux/time.h>
1/*
2 * arch/sh/boards/dreamcast/rtc.c
3 *
4 * Dreamcast AICA RTC routines.
5 *
6 * Copyright (c) 2001, 2002 M. R. Brown <mrbrown@0xd6.org>
7 * Copyright (c) 2002 Paul Mundt <lethal@chaoticdreams.org>
8 *
9 * Released under the terms of the GNU GPL v2.0.
10 *
11 */
12
13#include <linux/time.h>
14#include <asm/rtc.h>
15#include <asm/io.h>
14#include <linux/rtc.h>
15#include <linux/io.h>
16#include <linux/platform_device.h>
16
17/* The AICA RTC has an Epoch of 1/1/1950, so we must subtract 20 years (in
18 seconds) to get the standard Unix Epoch when getting the time, and add
19 20 years when setting the time. */
20#define TWENTY_YEARS ((20 * 365LU + 5) * 86400)
21
22/* The AICA RTC is represented by a 32-bit seconds counter stored in 2 16-bit
23 registers.*/
24#define AICA_RTC_SECS_H 0xa0710000
25#define AICA_RTC_SECS_L 0xa0710004
26
27/**
28 * aica_rtc_gettimeofday - Get the time from the AICA RTC
17
18/* The AICA RTC has an Epoch of 1/1/1950, so we must subtract 20 years (in
19 seconds) to get the standard Unix Epoch when getting the time, and add
20 20 years when setting the time. */
21#define TWENTY_YEARS ((20 * 365LU + 5) * 86400)
22
23/* The AICA RTC is represented by a 32-bit seconds counter stored in 2 16-bit
24 registers.*/
25#define AICA_RTC_SECS_H 0xa0710000
26#define AICA_RTC_SECS_L 0xa0710004
27
28/**
29 * aica_rtc_gettimeofday - Get the time from the AICA RTC
29 * @ts: pointer to resulting timespec
30 * @dev: the RTC device (ignored)
31 * @tm: pointer to resulting RTC time structure
30 *
31 * Grabs the current RTC seconds counter and adjusts it to the Unix Epoch.
32 */
32 *
33 * Grabs the current RTC seconds counter and adjusts it to the Unix Epoch.
34 */
33static void aica_rtc_gettimeofday(struct timespec *ts)
35static int aica_rtc_gettimeofday(struct device *dev, struct rtc_time *tm)
34{
35 unsigned long val1, val2;
36{
37 unsigned long val1, val2;
38 time64_t t;
36
37 do {
38 val1 = ((__raw_readl(AICA_RTC_SECS_H) & 0xffff) << 16) |
39 (__raw_readl(AICA_RTC_SECS_L) & 0xffff);
40
41 val2 = ((__raw_readl(AICA_RTC_SECS_H) & 0xffff) << 16) |
42 (__raw_readl(AICA_RTC_SECS_L) & 0xffff);
43 } while (val1 != val2);
44
39
40 do {
41 val1 = ((__raw_readl(AICA_RTC_SECS_H) & 0xffff) << 16) |
42 (__raw_readl(AICA_RTC_SECS_L) & 0xffff);
43
44 val2 = ((__raw_readl(AICA_RTC_SECS_H) & 0xffff) << 16) |
45 (__raw_readl(AICA_RTC_SECS_L) & 0xffff);
46 } while (val1 != val2);
47
45 ts->tv_sec = val1 - TWENTY_YEARS;
48 /* normalize to 1970..2106 time range */
49 t = (u32)(val1 - TWENTY_YEARS);
46
50
47 /* Can't get nanoseconds with just a seconds counter. */
48 ts->tv_nsec = 0;
51 rtc_time64_to_tm(t, tm);
52
53 return 0;
49}
50
51/**
52 * aica_rtc_settimeofday - Set the AICA RTC to the current time
54}
55
56/**
57 * aica_rtc_settimeofday - Set the AICA RTC to the current time
53 * @secs: contains the time_t to set
58 * @dev: the RTC device (ignored)
59 * @tm: pointer to new RTC time structure
54 *
55 * Adjusts the given @tv to the AICA Epoch and sets the RTC seconds counter.
56 */
60 *
61 * Adjusts the given @tv to the AICA Epoch and sets the RTC seconds counter.
62 */
57static int aica_rtc_settimeofday(const time_t secs)
63static int aica_rtc_settimeofday(struct device *dev, struct rtc_time *tm)
58{
59 unsigned long val1, val2;
64{
65 unsigned long val1, val2;
60 unsigned long adj = secs + TWENTY_YEARS;
66 time64_t secs = rtc_tm_to_time64(tm);
67 u32 adj = secs + TWENTY_YEARS;
61
62 do {
63 __raw_writel((adj & 0xffff0000) >> 16, AICA_RTC_SECS_H);
64 __raw_writel((adj & 0xffff), AICA_RTC_SECS_L);
65
66 val1 = ((__raw_readl(AICA_RTC_SECS_H) & 0xffff) << 16) |
67 (__raw_readl(AICA_RTC_SECS_L) & 0xffff);
68
69 val2 = ((__raw_readl(AICA_RTC_SECS_H) & 0xffff) << 16) |
70 (__raw_readl(AICA_RTC_SECS_L) & 0xffff);
71 } while (val1 != val2);
72
73 return 0;
74}
75
68
69 do {
70 __raw_writel((adj & 0xffff0000) >> 16, AICA_RTC_SECS_H);
71 __raw_writel((adj & 0xffff), AICA_RTC_SECS_L);
72
73 val1 = ((__raw_readl(AICA_RTC_SECS_H) & 0xffff) << 16) |
74 (__raw_readl(AICA_RTC_SECS_L) & 0xffff);
75
76 val2 = ((__raw_readl(AICA_RTC_SECS_H) & 0xffff) << 16) |
77 (__raw_readl(AICA_RTC_SECS_L) & 0xffff);
78 } while (val1 != val2);
79
80 return 0;
81}
82
76void aica_time_init(void)
83static const struct rtc_class_ops rtc_generic_ops = {
84 .read_time = aica_rtc_gettimeofday,
85 .set_time = aica_rtc_settimeofday,
86};
87
88static int __init aica_time_init(void)
77{
89{
78 rtc_sh_get_time = aica_rtc_gettimeofday;
79 rtc_sh_set_time = aica_rtc_settimeofday;
80}
90 struct platform_device *pdev;
81
91
92 pdev = platform_device_register_data(NULL, "rtc-generic", -1,
93 &rtc_generic_ops,
94 sizeof(rtc_generic_ops));
95
96 return PTR_ERR_OR_ZERO(pdev);
97}
98arch_initcall(aica_time_init);