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1/*
2 * include/asm-generic/rtc.h
3 *
4 * Author: Tom Rini <trini@mvista.com>
5 *
6 * Based on:
7 * drivers/char/rtc.c
8 *
9 * Please read the COPYING file for all license details.
10 */
11
12#ifndef __ASM_RTC_H__
13#define __ASM_RTC_H__
14
15#include <linux/mc146818rtc.h>
16#include <linux/rtc.h>
17#include <linux/bcd.h>
18#include <linux/delay.h>
19#ifdef CONFIG_ACPI
20#include <linux/acpi.h>
21#endif
22
23#define RTC_PIE 0x40 /* periodic interrupt enable */
24#define RTC_AIE 0x20 /* alarm interrupt enable */
25#define RTC_UIE 0x10 /* update-finished interrupt enable */
26
27/* some dummy definitions */
28#define RTC_BATT_BAD 0x100 /* battery bad */
29#define RTC_SQWE 0x08 /* enable square-wave output */
30#define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */
31#define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */
32#define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */
33
34/*
35 * Returns true if a clock update is in progress
36 */
37static inline unsigned char rtc_is_updating(void)
38{
39 unsigned char uip;
40 unsigned long flags;
41
42 spin_lock_irqsave(&rtc_lock, flags);
43 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
44 spin_unlock_irqrestore(&rtc_lock, flags);
45 return uip;
46}
47
48static inline unsigned int __get_rtc_time(struct rtc_time *time)
49{
50 unsigned char ctrl;
51 unsigned long flags;
52 unsigned char century = 0;
53
54#ifdef CONFIG_MACH_DECSTATION
55 unsigned int real_year;
56#endif
57
58 /*
59 * read RTC once any update in progress is done. The update
60 * can take just over 2ms. We wait 20ms. There is no need to
61 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
62 * If you need to know *exactly* when a second has started, enable
63 * periodic update complete interrupts, (via ioctl) and then
64 * immediately read /dev/rtc which will block until you get the IRQ.
65 * Once the read clears, read the RTC time (again via ioctl). Easy.
66 */
67 if (rtc_is_updating())
68 mdelay(20);
69
70 /*
71 * Only the values that we read from the RTC are set. We leave
72 * tm_wday, tm_yday and tm_isdst untouched. Even though the
73 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
74 * by the RTC when initially set to a non-zero value.
75 */
76 spin_lock_irqsave(&rtc_lock, flags);
77 time->tm_sec = CMOS_READ(RTC_SECONDS);
78 time->tm_min = CMOS_READ(RTC_MINUTES);
79 time->tm_hour = CMOS_READ(RTC_HOURS);
80 time->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
81 time->tm_mon = CMOS_READ(RTC_MONTH);
82 time->tm_year = CMOS_READ(RTC_YEAR);
83#ifdef CONFIG_MACH_DECSTATION
84 real_year = CMOS_READ(RTC_DEC_YEAR);
85#endif
86#ifdef CONFIG_ACPI
87 if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
88 acpi_gbl_FADT.century)
89 century = CMOS_READ(acpi_gbl_FADT.century);
90#endif
91 ctrl = CMOS_READ(RTC_CONTROL);
92 spin_unlock_irqrestore(&rtc_lock, flags);
93
94 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
95 {
96 time->tm_sec = bcd2bin(time->tm_sec);
97 time->tm_min = bcd2bin(time->tm_min);
98 time->tm_hour = bcd2bin(time->tm_hour);
99 time->tm_mday = bcd2bin(time->tm_mday);
100 time->tm_mon = bcd2bin(time->tm_mon);
101 time->tm_year = bcd2bin(time->tm_year);
102 century = bcd2bin(century);
103 }
104
105#ifdef CONFIG_MACH_DECSTATION
106 time->tm_year += real_year - 72;
107#endif
108
109 if (century)
110 time->tm_year += (century - 19) * 100;
111
112 /*
113 * Account for differences between how the RTC uses the values
114 * and how they are defined in a struct rtc_time;
115 */
116 if (time->tm_year <= 69)
117 time->tm_year += 100;
118
119 time->tm_mon--;
120
121 return RTC_24H;
122}
123
124#ifndef get_rtc_time
125#define get_rtc_time __get_rtc_time
126#endif
127
128/* Set the current date and time in the real time clock. */
129static inline int __set_rtc_time(struct rtc_time *time)
130{
131 unsigned long flags;
132 unsigned char mon, day, hrs, min, sec;
133 unsigned char save_control, save_freq_select;
134 unsigned int yrs;
135#ifdef CONFIG_MACH_DECSTATION
136 unsigned int real_yrs, leap_yr;
137#endif
138 unsigned char century = 0;
139
140 yrs = time->tm_year;
141 mon = time->tm_mon + 1; /* tm_mon starts at zero */
142 day = time->tm_mday;
143 hrs = time->tm_hour;
144 min = time->tm_min;
145 sec = time->tm_sec;
146
147 if (yrs > 255) /* They are unsigned */
148 return -EINVAL;
149
150 spin_lock_irqsave(&rtc_lock, flags);
151#ifdef CONFIG_MACH_DECSTATION
152 real_yrs = yrs;
153 leap_yr = ((!((yrs + 1900) % 4) && ((yrs + 1900) % 100)) ||
154 !((yrs + 1900) % 400));
155 yrs = 72;
156
157 /*
158 * We want to keep the year set to 73 until March
159 * for non-leap years, so that Feb, 29th is handled
160 * correctly.
161 */
162 if (!leap_yr && mon < 3) {
163 real_yrs--;
164 yrs = 73;
165 }
166#endif
167
168#ifdef CONFIG_ACPI
169 if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
170 acpi_gbl_FADT.century) {
171 century = (yrs + 1900) / 100;
172 yrs %= 100;
173 }
174#endif
175
176 /* These limits and adjustments are independent of
177 * whether the chip is in binary mode or not.
178 */
179 if (yrs > 169) {
180 spin_unlock_irqrestore(&rtc_lock, flags);
181 return -EINVAL;
182 }
183
184 if (yrs >= 100)
185 yrs -= 100;
186
187 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
188 || RTC_ALWAYS_BCD) {
189 sec = bin2bcd(sec);
190 min = bin2bcd(min);
191 hrs = bin2bcd(hrs);
192 day = bin2bcd(day);
193 mon = bin2bcd(mon);
194 yrs = bin2bcd(yrs);
195 century = bin2bcd(century);
196 }
197
198 save_control = CMOS_READ(RTC_CONTROL);
199 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
200 save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
201 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
202
203#ifdef CONFIG_MACH_DECSTATION
204 CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
205#endif
206 CMOS_WRITE(yrs, RTC_YEAR);
207 CMOS_WRITE(mon, RTC_MONTH);
208 CMOS_WRITE(day, RTC_DAY_OF_MONTH);
209 CMOS_WRITE(hrs, RTC_HOURS);
210 CMOS_WRITE(min, RTC_MINUTES);
211 CMOS_WRITE(sec, RTC_SECONDS);
212#ifdef CONFIG_ACPI
213 if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
214 acpi_gbl_FADT.century)
215 CMOS_WRITE(century, acpi_gbl_FADT.century);
216#endif
217
218 CMOS_WRITE(save_control, RTC_CONTROL);
219 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
220
221 spin_unlock_irqrestore(&rtc_lock, flags);
222
223 return 0;
224}
225
226#ifndef set_rtc_time
227#define set_rtc_time __set_rtc_time
228#endif
229
230static inline unsigned int get_rtc_ss(void)
231{
232 struct rtc_time h;
233
234 get_rtc_time(&h);
235 return h.tm_sec;
236}
237
238static inline int get_rtc_pll(struct rtc_pll_info *pll)
239{
240 return -EINVAL;
241}
242static inline int set_rtc_pll(struct rtc_pll_info *pll)
243{
244 return -EINVAL;
245}
246
247#endif /* __ASM_RTC_H__ */