blob: af6db6ec5b2a20db3d13861bdb97b878f8371f1e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Thomas Gleixnerfe599f92008-01-30 13:30:26 +01002 * RTC related functions
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 */
Jaswinder Singh Rajput8383d822009-03-21 16:56:37 +05304#include <linux/platform_device.h>
5#include <linux/mc146818rtc.h>
Thomas Gleixner1122b132008-01-30 13:30:27 +01006#include <linux/acpi.h>
Thomas Gleixnerfe599f92008-01-30 13:30:26 +01007#include <linux/bcd.h>
Paul Gortmaker69c60c82011-05-26 12:22:53 -04008#include <linux/export.h>
Stas Sergeev1da2e3d2008-06-12 15:21:54 -07009#include <linux/pnp.h>
Sebastian Andrzej Siewior3bcbaf62011-02-22 21:07:46 +010010#include <linux/of.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011
Ingo Molnarcdc79572008-01-30 13:32:39 +010012#include <asm/vsyscall.h>
Feng Tang7bd867d2009-09-10 10:48:56 +080013#include <asm/x86_init.h>
Jaswinder Singh Rajput8383d822009-03-21 16:56:37 +053014#include <asm/time.h>
Mathias Nyman35d47692011-11-15 14:46:52 -080015#include <asm/mrst.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
Thomas Gleixner1122b132008-01-30 13:30:27 +010017#ifdef CONFIG_X86_32
Thomas Gleixner1122b132008-01-30 13:30:27 +010018/*
19 * This is a special lock that is owned by the CPU and holds the index
20 * register we are working with. It is required for NMI access to the
21 * CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details.
22 */
Jaswinder Singh Rajput8383d822009-03-21 16:56:37 +053023volatile unsigned long cmos_lock;
Thomas Gleixner1122b132008-01-30 13:30:27 +010024EXPORT_SYMBOL(cmos_lock);
Jaswinder Singh Rajput8383d822009-03-21 16:56:37 +053025#endif /* CONFIG_X86_32 */
Thomas Gleixner1122b132008-01-30 13:30:27 +010026
Andi Kleenb62576a2008-02-09 16:16:58 +010027/* For two digit years assume time is always after that */
28#define CMOS_YEARS_OFFS 2000
29
Thomas Gleixner1122b132008-01-30 13:30:27 +010030DEFINE_SPINLOCK(rtc_lock);
31EXPORT_SYMBOL(rtc_lock);
32
Linus Torvalds1da177e2005-04-16 15:20:36 -070033/*
34 * In order to set the CMOS clock precisely, set_rtc_mmss has to be
35 * called 500 ms after the second nowtime has started, because when
36 * nowtime is written into the registers of the CMOS clock, it will
37 * jump to the next second precisely 500 ms later. Check the Motorola
38 * MC146818A or Dallas DS12887 data sheet for details.
39 *
40 * BUG: This routine does not handle hour overflow properly; it just
41 * sets the minutes. Usually you'll only notice that after reboot!
42 */
Thomas Gleixnerfe599f92008-01-30 13:30:26 +010043int mach_set_rtc_mmss(unsigned long nowtime)
Linus Torvalds1da177e2005-04-16 15:20:36 -070044{
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 int real_seconds, real_minutes, cmos_minutes;
46 unsigned char save_control, save_freq_select;
Matt Fleming47997d72011-09-21 16:08:03 +020047 unsigned long flags;
Jaswinder Singh Rajput8383d822009-03-21 16:56:37 +053048 int retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Matt Fleming47997d72011-09-21 16:08:03 +020050 spin_lock_irqsave(&rtc_lock, flags);
51
Thomas Gleixner1122b132008-01-30 13:30:27 +010052 /* tell the clock it's being set */
53 save_control = CMOS_READ(RTC_CONTROL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
55
Thomas Gleixner1122b132008-01-30 13:30:27 +010056 /* stop and reset prescaler */
57 save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
59
60 cmos_minutes = CMOS_READ(RTC_MINUTES);
61 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
Adrian Bunk357c6e62008-10-18 20:28:42 -070062 cmos_minutes = bcd2bin(cmos_minutes);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64 /*
65 * since we're only adjusting minutes and seconds,
66 * don't interfere with hour overflow. This avoids
67 * messing with unknown time zones but requires your
68 * RTC not to be off by more than 15 minutes
69 */
70 real_seconds = nowtime % 60;
71 real_minutes = nowtime / 60;
Thomas Gleixner1122b132008-01-30 13:30:27 +010072 /* correct for half hour time zone */
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
Thomas Gleixner1122b132008-01-30 13:30:27 +010074 real_minutes += 30;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 real_minutes %= 60;
76
77 if (abs(real_minutes - cmos_minutes) < 30) {
78 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
Adrian Bunk357c6e62008-10-18 20:28:42 -070079 real_seconds = bin2bcd(real_seconds);
80 real_minutes = bin2bcd(real_minutes);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 }
Jaswinder Singh Rajput8383d822009-03-21 16:56:37 +053082 CMOS_WRITE(real_seconds, RTC_SECONDS);
83 CMOS_WRITE(real_minutes, RTC_MINUTES);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 } else {
Stephen Hemminger3e5c1242011-01-12 16:59:31 -080085 printk_once(KERN_NOTICE
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 "set_rtc_mmss: can't update from %d to %d\n",
87 cmos_minutes, real_minutes);
88 retval = -1;
89 }
90
91 /* The following flags have to be released exactly in this order,
92 * otherwise the DS12887 (popular MC146818A clone with integrated
93 * battery and quartz) will not reset the oscillator and will not
94 * update precisely 500 ms later. You won't find this mentioned in
95 * the Dallas Semiconductor data sheets, but who believes data
96 * sheets anyway ... -- Markus Kuhn
97 */
98 CMOS_WRITE(save_control, RTC_CONTROL);
99 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
100
Matt Fleming47997d72011-09-21 16:08:03 +0200101 spin_unlock_irqrestore(&rtc_lock, flags);
102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 return retval;
104}
105
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100106unsigned long mach_get_cmos_time(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
Andi Kleen068c9222008-02-09 16:16:59 +0100108 unsigned int status, year, mon, day, hour, min, sec, century = 0;
Matt Fleming47997d72011-09-21 16:08:03 +0200109 unsigned long flags;
110
111 spin_lock_irqsave(&rtc_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
Thomas Gleixner1122b132008-01-30 13:30:27 +0100113 /*
114 * If UIP is clear, then we have >= 244 microseconds before
115 * RTC registers will be updated. Spec sheet says that this
116 * is the reliable way to read RTC - registers. If UIP is set
117 * then the register access might be invalid.
118 */
119 while ((CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
120 cpu_relax();
Matt Mackall63732c22006-03-28 01:55:58 -0800121
Thomas Gleixner1122b132008-01-30 13:30:27 +0100122 sec = CMOS_READ(RTC_SECONDS);
123 min = CMOS_READ(RTC_MINUTES);
124 hour = CMOS_READ(RTC_HOURS);
125 day = CMOS_READ(RTC_DAY_OF_MONTH);
126 mon = CMOS_READ(RTC_MONTH);
127 year = CMOS_READ(RTC_YEAR);
128
Andi Kleen45de7072008-02-09 16:17:01 +0100129#ifdef CONFIG_ACPI
Thomas Gleixner1122b132008-01-30 13:30:27 +0100130 if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
131 acpi_gbl_FADT.century)
132 century = CMOS_READ(acpi_gbl_FADT.century);
133#endif
134
Andi Kleen068c9222008-02-09 16:16:59 +0100135 status = CMOS_READ(RTC_CONTROL);
Andi Kleen45de7072008-02-09 16:17:01 +0100136 WARN_ON_ONCE(RTC_ALWAYS_BCD && (status & RTC_DM_BINARY));
Andi Kleen068c9222008-02-09 16:16:59 +0100137
Matt Fleming47997d72011-09-21 16:08:03 +0200138 spin_unlock_irqrestore(&rtc_lock, flags);
139
Andi Kleen068c9222008-02-09 16:16:59 +0100140 if (RTC_ALWAYS_BCD || !(status & RTC_DM_BINARY)) {
Adrian Bunk357c6e62008-10-18 20:28:42 -0700141 sec = bcd2bin(sec);
142 min = bcd2bin(min);
143 hour = bcd2bin(hour);
144 day = bcd2bin(day);
145 mon = bcd2bin(mon);
146 year = bcd2bin(year);
Matt Mackall41623b02006-03-28 01:56:09 -0800147 }
148
Thomas Gleixner1122b132008-01-30 13:30:27 +0100149 if (century) {
Adrian Bunk357c6e62008-10-18 20:28:42 -0700150 century = bcd2bin(century);
Thomas Gleixner1122b132008-01-30 13:30:27 +0100151 year += century * 100;
152 printk(KERN_INFO "Extended CMOS year: %d\n", century * 100);
Andi Kleenb62576a2008-02-09 16:16:58 +0100153 } else
Thomas Gleixner1122b132008-01-30 13:30:27 +0100154 year += CMOS_YEARS_OFFS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156 return mktime(year, mon, day, hour, min, sec);
157}
158
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100159/* Routines for accessing the CMOS RAM/RTC. */
160unsigned char rtc_cmos_read(unsigned char addr)
161{
162 unsigned char val;
163
164 lock_cmos_prefix(addr);
David P. Reed04aaa7b2008-02-17 16:56:39 -0500165 outb(addr, RTC_PORT(0));
166 val = inb(RTC_PORT(1));
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100167 lock_cmos_suffix(addr);
Jaswinder Singh Rajput8383d822009-03-21 16:56:37 +0530168
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100169 return val;
170}
171EXPORT_SYMBOL(rtc_cmos_read);
172
173void rtc_cmos_write(unsigned char val, unsigned char addr)
174{
175 lock_cmos_prefix(addr);
David P. Reed04aaa7b2008-02-17 16:56:39 -0500176 outb(addr, RTC_PORT(0));
177 outb(val, RTC_PORT(1));
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100178 lock_cmos_suffix(addr);
179}
180EXPORT_SYMBOL(rtc_cmos_write);
181
Feng Tang7bd867d2009-09-10 10:48:56 +0800182int update_persistent_clock(struct timespec now)
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100183{
Matt Fleming47997d72011-09-21 16:08:03 +0200184 return x86_platform.set_wallclock(now.tv_sec);
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100185}
186
187/* not static: needed by APM */
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200188void read_persistent_clock(struct timespec *ts)
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100189{
Matt Fleming47997d72011-09-21 16:08:03 +0200190 unsigned long retval;
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100191
Feng Tang7bd867d2009-09-10 10:48:56 +0800192 retval = x86_platform.get_wallclock();
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100193
Martin Schwidefskyd4f587c2009-08-14 15:47:31 +0200194 ts->tv_sec = retval;
195 ts->tv_nsec = 0;
Thomas Gleixnerfe599f92008-01-30 13:30:26 +0100196}
197
Ingo Molnar92767af2008-01-30 13:32:40 +0100198unsigned long long native_read_tsc(void)
Ingo Molnarcdc79572008-01-30 13:32:39 +0100199{
Ingo Molnar92767af2008-01-30 13:32:40 +0100200 return __native_read_tsc();
Ingo Molnarcdc79572008-01-30 13:32:39 +0100201}
Ingo Molnar92767af2008-01-30 13:32:40 +0100202EXPORT_SYMBOL(native_read_tsc);
203
Stas Sergeev1da2e3d2008-06-12 15:21:54 -0700204
205static struct resource rtc_resources[] = {
206 [0] = {
207 .start = RTC_PORT(0),
208 .end = RTC_PORT(1),
209 .flags = IORESOURCE_IO,
210 },
211 [1] = {
212 .start = RTC_IRQ,
213 .end = RTC_IRQ,
214 .flags = IORESOURCE_IRQ,
215 }
216};
217
218static struct platform_device rtc_device = {
219 .name = "rtc_cmos",
220 .id = -1,
221 .resource = rtc_resources,
222 .num_resources = ARRAY_SIZE(rtc_resources),
223};
224
225static __init int add_rtc_cmos(void)
226{
227#ifdef CONFIG_PNP
Bjorn Helgaas758a7f72008-10-14 17:01:03 -0600228 static const char *ids[] __initconst =
229 { "PNP0b00", "PNP0b01", "PNP0b02", };
230 struct pnp_dev *dev;
231 struct pnp_id *id;
232 int i;
233
234 pnp_for_each_dev(dev) {
235 for (id = dev->id; id; id = id->next) {
236 for (i = 0; i < ARRAY_SIZE(ids); i++) {
237 if (compare_pnp_id(id, ids[i]) != 0)
238 return 0;
239 }
240 }
241 }
242#endif
Sebastian Andrzej Siewior3bcbaf62011-02-22 21:07:46 +0100243 if (of_have_populated_dt())
244 return 0;
Bjorn Helgaas758a7f72008-10-14 17:01:03 -0600245
Mathias Nyman35d47692011-11-15 14:46:52 -0800246 /* Intel MID platforms don't have ioport rtc */
247 if (mrst_identify_cpu())
248 return -ENODEV;
249
Stas Sergeev1da2e3d2008-06-12 15:21:54 -0700250 platform_device_register(&rtc_device);
Bjorn Helgaas758a7f72008-10-14 17:01:03 -0600251 dev_info(&rtc_device.dev,
252 "registered platform RTC device (no PNP device found)\n");
Jaswinder Singh Rajput8383d822009-03-21 16:56:37 +0530253
Stas Sergeev1da2e3d2008-06-12 15:21:54 -0700254 return 0;
255}
256device_initcall(add_rtc_cmos);