1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * linux/arch/sh/boards/sh03/rtc.c -- CTP/PCI-SH03 on-chip RTC support |
4 | * |
5 | * Copyright (C) 2004 Saito.K & Jeanne(ksaito@interface.co.jp) |
6 | * |
7 | */ |
8 | |
9 | #include <linux/init.h> |
10 | #include <linux/kernel.h> |
11 | #include <linux/sched.h> |
12 | #include <linux/time.h> |
13 | #include <linux/bcd.h> |
14 | #include <linux/spinlock.h> |
15 | #include <linux/io.h> |
16 | #include <linux/rtc.h> |
17 | #include <linux/platform_device.h> |
18 | |
19 | #define RTC_BASE 0xb0000000 |
20 | #define RTC_SEC1 (RTC_BASE + 0) |
21 | #define RTC_SEC10 (RTC_BASE + 1) |
22 | #define RTC_MIN1 (RTC_BASE + 2) |
23 | #define RTC_MIN10 (RTC_BASE + 3) |
24 | #define RTC_HOU1 (RTC_BASE + 4) |
25 | #define RTC_HOU10 (RTC_BASE + 5) |
26 | #define RTC_WEE1 (RTC_BASE + 6) |
27 | #define RTC_DAY1 (RTC_BASE + 7) |
28 | #define RTC_DAY10 (RTC_BASE + 8) |
29 | #define RTC_MON1 (RTC_BASE + 9) |
30 | #define RTC_MON10 (RTC_BASE + 10) |
31 | #define RTC_YEA1 (RTC_BASE + 11) |
32 | #define RTC_YEA10 (RTC_BASE + 12) |
33 | #define RTC_YEA100 (RTC_BASE + 13) |
34 | #define RTC_YEA1000 (RTC_BASE + 14) |
35 | #define RTC_CTL (RTC_BASE + 15) |
36 | #define RTC_BUSY 1 |
37 | #define RTC_STOP 2 |
38 | |
39 | static DEFINE_SPINLOCK(sh03_rtc_lock); |
40 | |
41 | static int sh03_rtc_gettimeofday(struct device *dev, struct rtc_time *tm) |
42 | { |
43 | unsigned int year, mon, day, hour, min, sec; |
44 | |
45 | spin_lock(lock: &sh03_rtc_lock); |
46 | again: |
47 | do { |
48 | sec = (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10; |
49 | min = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10; |
50 | hour = (__raw_readb(RTC_HOU1) & 0xf) + (__raw_readb(RTC_HOU10) & 0xf) * 10; |
51 | day = (__raw_readb(RTC_DAY1) & 0xf) + (__raw_readb(RTC_DAY10) & 0xf) * 10; |
52 | mon = (__raw_readb(RTC_MON1) & 0xf) + (__raw_readb(RTC_MON10) & 0xf) * 10; |
53 | year = (__raw_readb(RTC_YEA1) & 0xf) + (__raw_readb(RTC_YEA10) & 0xf) * 10 |
54 | + (__raw_readb(RTC_YEA100 ) & 0xf) * 100 |
55 | + (__raw_readb(RTC_YEA1000) & 0xf) * 1000; |
56 | } while (sec != (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10); |
57 | if (year == 0 || mon < 1 || mon > 12 || day > 31 || day < 1 || |
58 | hour > 23 || min > 59 || sec > 59) { |
59 | printk(KERN_ERR |
60 | "SH-03 RTC: invalid value, resetting to 1 Jan 2000\n" ); |
61 | printk("year=%d, mon=%d, day=%d, hour=%d, min=%d, sec=%d\n" , |
62 | year, mon, day, hour, min, sec); |
63 | |
64 | __raw_writeb(val: 0, RTC_SEC1); __raw_writeb(val: 0, RTC_SEC10); |
65 | __raw_writeb(val: 0, RTC_MIN1); __raw_writeb(val: 0, RTC_MIN10); |
66 | __raw_writeb(val: 0, RTC_HOU1); __raw_writeb(val: 0, RTC_HOU10); |
67 | __raw_writeb(val: 6, RTC_WEE1); |
68 | __raw_writeb(val: 1, RTC_DAY1); __raw_writeb(val: 0, RTC_DAY10); |
69 | __raw_writeb(val: 1, RTC_MON1); __raw_writeb(val: 0, RTC_MON10); |
70 | __raw_writeb(val: 0, RTC_YEA1); __raw_writeb(val: 0, RTC_YEA10); |
71 | __raw_writeb(val: 0, RTC_YEA100); |
72 | __raw_writeb(val: 2, RTC_YEA1000); |
73 | __raw_writeb(val: 0, RTC_CTL); |
74 | goto again; |
75 | } |
76 | |
77 | spin_unlock(lock: &sh03_rtc_lock); |
78 | |
79 | tm->tm_sec = sec; |
80 | tm->tm_min = min; |
81 | tm->tm_hour = hour; |
82 | tm->tm_mday = day; |
83 | tm->tm_mon = mon; |
84 | tm->tm_year = year - 1900; |
85 | |
86 | return 0; |
87 | } |
88 | |
89 | static int set_rtc_mmss(struct rtc_time *tm) |
90 | { |
91 | int retval = 0; |
92 | int real_seconds, real_minutes, cmos_minutes; |
93 | int i; |
94 | |
95 | /* gets recalled with irq locally disabled */ |
96 | spin_lock(lock: &sh03_rtc_lock); |
97 | for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */ |
98 | if (!(__raw_readb(RTC_CTL) & RTC_BUSY)) |
99 | break; |
100 | cmos_minutes = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10; |
101 | real_seconds = tm->tm_sec; |
102 | real_minutes = tm->tm_min; |
103 | if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1) |
104 | real_minutes += 30; /* correct for half hour time zone */ |
105 | real_minutes %= 60; |
106 | |
107 | if (abs(real_minutes - cmos_minutes) < 30) { |
108 | __raw_writeb(val: real_seconds % 10, RTC_SEC1); |
109 | __raw_writeb(val: real_seconds / 10, RTC_SEC10); |
110 | __raw_writeb(val: real_minutes % 10, RTC_MIN1); |
111 | __raw_writeb(val: real_minutes / 10, RTC_MIN10); |
112 | } else { |
113 | printk_once(KERN_NOTICE |
114 | "set_rtc_mmss: can't update from %d to %d\n" , |
115 | cmos_minutes, real_minutes); |
116 | retval = -EINVAL; |
117 | } |
118 | spin_unlock(lock: &sh03_rtc_lock); |
119 | |
120 | return retval; |
121 | } |
122 | |
123 | int sh03_rtc_settimeofday(struct device *dev, struct rtc_time *tm) |
124 | { |
125 | return set_rtc_mmss(tm); |
126 | } |
127 | |
128 | static const struct rtc_class_ops rtc_generic_ops = { |
129 | .read_time = sh03_rtc_gettimeofday, |
130 | .set_time = sh03_rtc_settimeofday, |
131 | }; |
132 | |
133 | static int __init sh03_time_init(void) |
134 | { |
135 | struct platform_device *pdev; |
136 | |
137 | pdev = platform_device_register_data(NULL, name: "rtc-generic" , id: -1, |
138 | data: &rtc_generic_ops, |
139 | size: sizeof(rtc_generic_ops)); |
140 | |
141 | return PTR_ERR_OR_ZERO(ptr: pdev); |
142 | } |
143 | arch_initcall(sh03_time_init); |
144 | |