drivers/rtc/rtc-ds1302.c: handle write protection

This chip has a control register and can prevent altering saved clock.
Without this patch we could have:

(arm)root@pac14:~# date
Tue May 21 03:08:27 MSK 2013
(arm)root@pac14:~# /etc/init.d/hwclock.sh show
Tue May 21 11:13:58 2013  -0.067322 seconds
(arm)root@pac14:~# /etc/init.d/hwclock.sh stop
[info] Saving the system clock.
[info] Hardware Clock updated to Tue May 21 03:09:01 MSK 2013.
(arm)root@pac14:~# /etc/init.d/hwclock.sh show
Tue May 21 11:14:15 2013  -0.624272 seconds

The patch enables write access to rtc before the driver tries to write
time and re-disables when time data is written.

Signed-off-by: Sergey Yanovich <[email protected]>
Acked-by: Marc Zyngier <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Sachin Kamat <[email protected]>
Cc: Jingoo Han <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions