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authorThomas Gleixner <tglx@linutronix.de>2008-01-30 07:30:27 -0500
committerIngo Molnar <mingo@elte.hu>2008-01-30 07:30:27 -0500
commit1122b134bcd6e77c5a4117952b8cbc55c8d018bc (patch)
treee4b0df9c7fb4686357a33c00d037898725ab5b82 /arch/x86/kernel/time_64.c
parentfe599f9fbc5d470ec5b55d08f2bbb991ddecbbc8 (diff)
x86: share rtc code
Remove the rtc code from time_64.c and add the extra bits to the i386 path. The ACPI century check is probably valid for i386 as well, but this is material for a separate patch. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/time_64.c')
-rw-r--r--arch/x86/kernel/time_64.c157
1 files changed, 0 insertions, 157 deletions
diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c
index 0a01504586a5..64cd03ed9bfc 100644
--- a/arch/x86/kernel/time_64.c
+++ b/arch/x86/kernel/time_64.c
@@ -46,9 +46,6 @@
46#include <asm/nmi.h> 46#include <asm/nmi.h>
47#include <asm/vgtod.h> 47#include <asm/vgtod.h>
48 48
49DEFINE_SPINLOCK(rtc_lock);
50EXPORT_SYMBOL(rtc_lock);
51
52volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES; 49volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
53 50
54unsigned long profile_pc(struct pt_regs *regs) 51unsigned long profile_pc(struct pt_regs *regs)
@@ -69,103 +66,6 @@ unsigned long profile_pc(struct pt_regs *regs)
69} 66}
70EXPORT_SYMBOL(profile_pc); 67EXPORT_SYMBOL(profile_pc);
71 68
72/* Routines for accessing the CMOS RAM/RTC. */
73unsigned char rtc_cmos_read(unsigned char addr)
74{
75 unsigned char val;
76 lock_cmos_prefix(addr);
77 outb_p(addr, RTC_PORT(0));
78 val = inb_p(RTC_PORT(1));
79 lock_cmos_suffix(addr);
80 return val;
81}
82EXPORT_SYMBOL(rtc_cmos_read);
83
84void rtc_cmos_write(unsigned char val, unsigned char addr)
85{
86 lock_cmos_prefix(addr);
87 outb_p(addr, RTC_PORT(0));
88 outb_p(val, RTC_PORT(1));
89 lock_cmos_suffix(addr);
90}
91EXPORT_SYMBOL(rtc_cmos_write);
92
93/*
94 * In order to set the CMOS clock precisely, set_rtc_mmss has to be called 500
95 * ms after the second nowtime has started, because when nowtime is written
96 * into the registers of the CMOS clock, it will jump to the next second
97 * precisely 500 ms later. Check the Motorola MC146818A or Dallas DS12887 data
98 * sheet for details.
99 */
100
101static int set_rtc_mmss(unsigned long nowtime)
102{
103 int retval = 0;
104 int real_seconds, real_minutes, cmos_minutes;
105 unsigned char control, freq_select;
106 unsigned long flags;
107
108/*
109 * set_rtc_mmss is called when irqs are enabled, so disable irqs here
110 */
111 spin_lock_irqsave(&rtc_lock, flags);
112/*
113 * Tell the clock it's being set and stop it.
114 */
115 control = CMOS_READ(RTC_CONTROL);
116 CMOS_WRITE(control | RTC_SET, RTC_CONTROL);
117
118 freq_select = CMOS_READ(RTC_FREQ_SELECT);
119 CMOS_WRITE(freq_select | RTC_DIV_RESET2, RTC_FREQ_SELECT);
120
121 cmos_minutes = CMOS_READ(RTC_MINUTES);
122 BCD_TO_BIN(cmos_minutes);
123
124/*
125 * since we're only adjusting minutes and seconds, don't interfere with hour
126 * overflow. This avoids messing with unknown time zones but requires your RTC
127 * not to be off by more than 15 minutes. Since we're calling it only when
128 * our clock is externally synchronized using NTP, this shouldn't be a problem.
129 */
130
131 real_seconds = nowtime % 60;
132 real_minutes = nowtime / 60;
133 if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1)
134 real_minutes += 30; /* correct for half hour time zone */
135 real_minutes %= 60;
136
137 if (abs(real_minutes - cmos_minutes) >= 30) {
138 printk(KERN_WARNING "time.c: can't update CMOS clock "
139 "from %d to %d\n", cmos_minutes, real_minutes);
140 retval = -1;
141 } else {
142 BIN_TO_BCD(real_seconds);
143 BIN_TO_BCD(real_minutes);
144 CMOS_WRITE(real_seconds, RTC_SECONDS);
145 CMOS_WRITE(real_minutes, RTC_MINUTES);
146 }
147
148/*
149 * The following flags have to be released exactly in this order, otherwise the
150 * DS12887 (popular MC146818A clone with integrated battery and quartz) will
151 * not reset the oscillator and will not update precisely 500 ms later. You
152 * won't find this mentioned in the Dallas Semiconductor data sheets, but who
153 * believes data sheets anyway ... -- Markus Kuhn
154 */
155
156 CMOS_WRITE(control, RTC_CONTROL);
157 CMOS_WRITE(freq_select, RTC_FREQ_SELECT);
158
159 spin_unlock_irqrestore(&rtc_lock, flags);
160
161 return retval;
162}
163
164int update_persistent_clock(struct timespec now)
165{
166 return set_rtc_mmss(now.tv_sec);
167}
168
169static irqreturn_t timer_event_interrupt(int irq, void *dev_id) 69static irqreturn_t timer_event_interrupt(int irq, void *dev_id)
170{ 70{
171 add_pda(irq0_irqs, 1); 71 add_pda(irq0_irqs, 1);
@@ -175,63 +75,6 @@ static irqreturn_t timer_event_interrupt(int irq, void *dev_id)
175 return IRQ_HANDLED; 75 return IRQ_HANDLED;
176} 76}
177 77
178unsigned long read_persistent_clock(void)
179{
180 unsigned int year, mon, day, hour, min, sec;
181 unsigned long flags;
182 unsigned century = 0;
183
184 spin_lock_irqsave(&rtc_lock, flags);
185 /*
186 * if UIP is clear, then we have >= 244 microseconds before RTC
187 * registers will be updated. Spec sheet says that this is the
188 * reliable way to read RTC - registers invalid (off bus) during update
189 */
190 while ((CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
191 cpu_relax();
192
193
194 /* now read all RTC registers while stable with interrupts disabled */
195 sec = CMOS_READ(RTC_SECONDS);
196 min = CMOS_READ(RTC_MINUTES);
197 hour = CMOS_READ(RTC_HOURS);
198 day = CMOS_READ(RTC_DAY_OF_MONTH);
199 mon = CMOS_READ(RTC_MONTH);
200 year = CMOS_READ(RTC_YEAR);
201#ifdef CONFIG_ACPI
202 if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
203 acpi_gbl_FADT.century)
204 century = CMOS_READ(acpi_gbl_FADT.century);
205#endif
206 spin_unlock_irqrestore(&rtc_lock, flags);
207
208 /*
209 * We know that x86-64 always uses BCD format, no need to check the
210 * config register.
211 */
212
213 BCD_TO_BIN(sec);
214 BCD_TO_BIN(min);
215 BCD_TO_BIN(hour);
216 BCD_TO_BIN(day);
217 BCD_TO_BIN(mon);
218 BCD_TO_BIN(year);
219
220 if (century) {
221 BCD_TO_BIN(century);
222 year += century * 100;
223 printk(KERN_INFO "Extended CMOS year: %d\n", century * 100);
224 } else {
225 /*
226 * x86-64 systems only exists since 2002.
227 * This will work up to Dec 31, 2100
228 */
229 year += 2000;
230 }
231
232 return mktime(year, mon, day, hour, min, sec);
233}
234
235/* calibrate_cpu is used on systems with fixed rate TSCs to determine 78/* calibrate_cpu is used on systems with fixed rate TSCs to determine
236 * processor frequency */ 79 * processor frequency */
237#define TICK_COUNT 100000000 80#define TICK_COUNT 100000000