PATCH: Allow reading CMOS day of week register

From: Alan Cox
Date: Mon Jan 09 2006 - 11:54:32 EST


Someone wanted access to this usually unused (and unused by Linux) value
for the day of week. Existing kernels have the field in the struct but
return 0 always. This updates the kernel to fill in the field. The usual
case of 'not set' conveniently is 0.

Signed-off-by: Alan Cox <alan@xxxxxxxxxx>

diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.15-mm2/drivers/char/rtc.c linux-2.6.15-mm2/drivers/char/rtc.c
--- linux.vanilla-2.6.15-mm2/drivers/char/rtc.c 2006-01-09 14:31:46.000000000 +0000
+++ linux-2.6.15-mm2/drivers/char/rtc.c 2006-01-09 14:40:29.000000000 +0000
@@ -46,10 +46,10 @@
* 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init
* 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
* CONFIG_HPET_EMULATE_RTC
- *
+ * 1.12ac Alan Cox: Allow read access to the day of week register
*/

-#define RTC_VERSION "1.12"
+#define RTC_VERSION "1.12ac"

#define RTC_IO_EXTENT 0x8

@@ -1250,9 +1250,9 @@

/*
* Only the values that we read from the RTC are set. We leave
- * tm_wday, tm_yday and tm_isdst untouched. Even though the
- * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
- * by the RTC when initially set to a non-zero value.
+ * tm_wday, tm_yday and tm_isdst untouched. Note that while the
+ * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is
+ * only updated by the RTC when initially set to a non-zero value.
*/
spin_lock_irq(&rtc_lock);
rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
@@ -1261,6 +1261,9 @@
rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
+ /* Only set from 2.6.16 onwards */
+ rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);
+
#ifdef CONFIG_MACH_DECSTATION
real_year = CMOS_READ(RTC_DEC_YEAR);
#endif
@@ -1275,6 +1278,7 @@
BCD_TO_BIN(rtc_tm->tm_mday);
BCD_TO_BIN(rtc_tm->tm_mon);
BCD_TO_BIN(rtc_tm->tm_year);
+ BCD_TO_BIN(rtc_tm->tm_wday);
}

#ifdef CONFIG_MACH_DECSTATION

-
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