1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
|
/*
* RTC related functions
*/
#include <linux/platform_device.h>
#include <linux/mc146818rtc.h>
#include <linux/acpi.h>
#include <linux/bcd.h>
#include <linux/export.h>
#include <linux/pnp.h>
#include <linux/of.h>
#include <asm/vsyscall.h>
#include <asm/x86_init.h>
#include <asm/time.h>
#include <asm/mrst.h>
#ifdef CONFIG_X86_32
/*
* This is a special lock that is owned by the CPU and holds the index
* register we are working with. It is required for NMI access to the
* CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details.
*/
volatile unsigned long cmos_lock;
EXPORT_SYMBOL(cmos_lock);
#endif /* CONFIG_X86_32 */
/* For two digit years assume time is always after that */
#define CMOS_YEARS_OFFS 2000
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
/*
* In order to set the CMOS clock precisely, set_rtc_mmss has to be
* called 500 ms after the second nowtime has started, because when
* nowtime is written into the registers of the CMOS clock, it will
* jump to the next second precisely 500 ms later. Check the Motorola
* MC146818A or Dallas DS12887 data sheet for details.
*
* BUG: This routine does not handle hour overflow properly; it just
* sets the minutes. Usually you'll only notice that after reboot!
*/
int mach_set_rtc_mmss(unsigned long nowtime)
{
int real_seconds, real_minutes, cmos_minutes;
unsigned char save_control, save_freq_select;
unsigned long flags;
int retval = 0;
spin_lock_irqsave(&rtc_lock, flags);
/* tell the clock it's being set */
save_control = CMOS_READ(RTC_CONTROL);
CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
/* stop and reset prescaler */
save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
cmos_minutes = CMOS_READ(RTC_MINUTES);
if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
cmos_minutes = bcd2bin(cmos_minutes);
/*
* since we're only adjusting minutes and seconds,
* don't interfere with hour overflow. This avoids
* messing with unknown time zones but requires your
* RTC not to be off by more than 15 minutes
*/
real_seconds = nowtime % 60;
real_minutes = nowtime / 60;
/* correct for half hour time zone */
if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
real_minutes += 30;
real_minutes %= 60;
if (abs(real_minutes - cmos_minutes) < 30) {
if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
real_seconds = bin2bcd(real_seconds);
real_minutes = bin2bcd(real_minutes);
}
CMOS_WRITE(real_seconds, RTC_SECONDS);
CMOS_WRITE(real_minutes, RTC_MINUTES);
} else {
printk_once(KERN_NOTICE
"set_rtc_mmss: can't update from %d to %d\n",
cmos_minutes, real_minutes);
retval = -1;
}
/* The following flags have to be released exactly in this order,
* otherwise the DS12887 (popular MC146818A clone with integrated
* battery and quartz) will not reset the oscillator and will not
* update precisely 500 ms later. You won't find this mentioned in
* the Dallas Semiconductor data sheets, but who believes data
* sheets anyway ... -- Markus Kuhn
*/
CMOS_WRITE(save_control, RTC_CONTROL);
CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
spin_unlock_irqrestore(&rtc_lock, flags);
return retval;
}
unsigned long mach_get_cmos_time(void)
{
unsigned int status, year, mon, day, hour, min, sec, century = 0;
unsigned long flags;
spin_lock_irqsave(&rtc_lock, flags);
/*
* If UIP is clear, then we have >= 244 microseconds before
* RTC registers will be updated. Spec sheet says that this
* is the reliable way to read RTC - registers. If UIP is set
* then the register access might be invalid.
*/
while ((CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
cpu_relax();
sec = CMOS_READ(RTC_SECONDS);
min = CMOS_READ(RTC_MINUTES);
hour = CMOS_READ(RTC_HOURS);
day = CMOS_READ(RTC_DAY_OF_MONTH);
mon = CMOS_READ(RTC_MONTH);
year = CMOS_READ(RTC_YEAR);
#ifdef CONFIG_ACPI
if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
acpi_gbl_FADT.century)
century = CMOS_READ(acpi_gbl_FADT.century);
#endif
status = CMOS_READ(RTC_CONTROL);
WARN_ON_ONCE(RTC_ALWAYS_BCD && (status & RTC_DM_BINARY));
spin_unlock_irqrestore(&rtc_lock, flags);
if (RTC_ALWAYS_BCD || !(status & RTC_DM_BINARY)) {
sec = bcd2bin(sec);
min = bcd2bin(min);
hour = bcd2bin(hour);
day = bcd2bin(day);
mon = bcd2bin(mon);
year = bcd2bin(year);
}
if (century) {
century = bcd2bin(century);
year += century * 100;
printk(KERN_INFO "Extended CMOS year: %d\n", century * 100);
} else
year += CMOS_YEARS_OFFS;
return mktime(year, mon, day, hour, min, sec);
}
/* Routines for accessing the CMOS RAM/RTC. */
unsigned char rtc_cmos_read(unsigned char addr)
{
unsigned char val;
lock_cmos_prefix(addr);
outb(addr, RTC_PORT(0));
val = inb(RTC_PORT(1));
lock_cmos_suffix(addr);
return val;
}
EXPORT_SYMBOL(rtc_cmos_read);
void rtc_cmos_write(unsigned char val, unsigned char addr)
{
lock_cmos_prefix(addr);
outb(addr, RTC_PORT(0));
outb(val, RTC_PORT(1));
lock_cmos_suffix(addr);
}
EXPORT_SYMBOL(rtc_cmos_write);
int update_persistent_clock(struct timespec now)
{
return x86_platform.set_wallclock(now.tv_sec);
}
/* not static: needed by APM */
void read_persistent_clock(struct timespec *ts)
{
unsigned long retval;
retval = x86_platform.get_wallclock();
ts->tv_sec = retval;
ts->tv_nsec = 0;
}
static struct resource rtc_resources[] = {
[0] = {
.start = RTC_PORT(0),
.end = RTC_PORT(1),
.flags = IORESOURCE_IO,
},
[1] = {
.start = RTC_IRQ,
.end = RTC_IRQ,
.flags = IORESOURCE_IRQ,
}
};
static struct platform_device rtc_device = {
.name = "rtc_cmos",
.id = -1,
.resource = rtc_resources,
.num_resources = ARRAY_SIZE(rtc_resources),
};
static __init int add_rtc_cmos(void)
{
#ifdef CONFIG_PNP
static const char * const const ids[] __initconst =
{ "PNP0b00", "PNP0b01", "PNP0b02", };
struct pnp_dev *dev;
struct pnp_id *id;
int i;
pnp_for_each_dev(dev) {
for (id = dev->id; id; id = id->next) {
for (i = 0; i < ARRAY_SIZE(ids); i++) {
if (compare_pnp_id(id, ids[i]) != 0)
return 0;
}
}
}
#endif
if (of_have_populated_dt())
return 0;
/* Intel MID platforms don't have ioport rtc */
if (mrst_identify_cpu())
return -ENODEV;
platform_device_register(&rtc_device);
dev_info(&rtc_device.dev,
"registered platform RTC device (no PNP device found)\n");
return 0;
}
device_initcall(add_rtc_cmos);
|
