rtc: add support for ST M41T94 SPI RTC

This patch adds kernel driver for M41T94 RTC chip connected via SPI.
I've tested it on two different AT91-based hardwares.

This is third revision of the patch: some comments made by
Alessandro Zummo fixed.

Revision two added support for century bit and fixes.

Signed-off-by: Kim B. Heino <Kim.Heino@bluegiga.com>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index fc85bf2e4a97..beffb834c440 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -273,6 +273,15 @@ comment "SPI RTC drivers"
 
 if SPI_MASTER
 
+config RTC_DRV_M41T94
+        tristate "ST M41T94"
+        help
+          If you say yes here you will get support for the
+          ST M41T94 SPI RTC chip.
+
+          This driver can also be built as a module. If so, the module
+          will be called rtc-m41t94.
+
 config RTC_DRV_MAX6902
         tristate "Maxim MAX6902"
         help