From: Michael Hamel Date: Fri, 4 Jul 2008 16:59:30 +0000 (-0700) Subject: rtc-x1205: Fix alarm set X-Git-Tag: v2.6.26-rc9~51 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=471d47e3223311d2638755717f97dc9a298f6dc9;p=pandora-kernel.git rtc-x1205: Fix alarm set I have discovered that the current version of rtc-x1205.c does not work correctly when asked to set the alarm time by the RTC_WKALM_SET ioctl() call. This happens because the alarm registers do not behave like the current-time registers. They are non-volatile. Two things go wrong: - the X1205 requires a 10 msec delay after any attempt to write to the non-volatile registers. The x1205_set_datetime() routine does the write as 8 single-byte writes without any delay. Only the first write succeeds. The second is NAKed because the chip is busy. - the X1205 resets the RWEL bit after any write to the non-volatile registers. This would lock out any further writes after the first even with a 10msec delay. I fix this by doing a single 8-byte write and then waiting 10msec for the chip to be ready. A side effect of this change is that it will speed up x1205_rtc_set_time() which uses the same code. I have also implemented the 'enable' bit in the rtc_wkalm structure, which the existing driver does not attempt to do. I have modified both x1205_rtc_set_alarm() to set the AL0E bit, and x1205_rtc_read_alarm() to return it. I have tested this patch on a LinkSys NSLU2 under OpenWRT, but on no other hardware. On the NSLU2 the X1205 correctly asserts its IRQ pin when the alarm time matches the current time. [akpm@linux-foundation.org: clean up over-parenthesisation] Signed-off-by: Michael Hamel Signed-off-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed