[PATCH] RTC: Remove RTC UIP synchronization on ARM
Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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@ -34,27 +34,12 @@ static int rtc_base;
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static unsigned long __init get_isa_cmos_time(void)
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static unsigned long __init get_isa_cmos_time(void)
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{
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{
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unsigned int year, mon, day, hour, min, sec;
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unsigned int year, mon, day, hour, min, sec;
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int i;
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// check to see if the RTC makes sense.....
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// check to see if the RTC makes sense.....
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if ((CMOS_READ(RTC_VALID) & RTC_VRT) == 0)
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if ((CMOS_READ(RTC_VALID) & RTC_VRT) == 0)
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return mktime(1970, 1, 1, 0, 0, 0);
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return mktime(1970, 1, 1, 0, 0, 0);
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/* The Linux interpretation of the CMOS clock register contents:
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do {
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* When the Update-In-Progress (UIP) flag goes from 1 to 0, the
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* RTC registers show the second which has precisely just started.
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* Let's hope other operating systems interpret the RTC the same way.
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*/
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/* read RTC exactly on falling edge of update flag */
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for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */
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if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)
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break;
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for (i = 0 ; i < 1000000 ; i++) /* must try at least 2.228 ms */
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if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
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break;
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do { /* Isn't this overkill ? UIP above should guarantee consistency */
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sec = CMOS_READ(RTC_SECONDS);
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sec = CMOS_READ(RTC_SECONDS);
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min = CMOS_READ(RTC_MINUTES);
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min = CMOS_READ(RTC_MINUTES);
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hour = CMOS_READ(RTC_HOURS);
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hour = CMOS_READ(RTC_HOURS);
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