rtc-proc: permit the /proc/driver/rtc device to use other devices

To get time information via /proc/driver/rtc, only the first device (rtc0)
is used.  If the rtcN (eg.  rtc1 or rtc2) is used for the system clock,
there is no way to get information of rtcN via /proc/driver/rtc.  With
this patch, the time data can be retrieved from the system clock RTC.

If the RTC_HCTOSYS_DEVICE is not defined, then rtc0 is used by default.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt
index 250160469d83..32aa4002de4a 100644
--- a/Documentation/rtc.txt
+++ b/Documentation/rtc.txt
@@ -119,8 +119,9 @@ three different userspace interfaces:
     *   /sys/class/rtc/rtcN ... sysfs attributes support readonly
         access to some RTC attributes.
 
-    *   /proc/driver/rtc ... the first RTC (rtc0) may expose itself
-        using a procfs interface.  More information is (currently) shown
+    *   /proc/driver/rtc ... the system clock RTC may expose itself
+        using a procfs interface. If there is no RTC for the system clock,
+        rtc0 is used by default. More information is (currently) shown
         here than through sysfs.
 
 The RTC Class framework supports a wide variety of RTCs, ranging from those