rtc: update documentation wrt irq_set_freq
Document the proper use of the irq_set_freq function.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: 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>
diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt
index e20b19c..804a7cf 100644
--- a/Documentation/rtc.txt
+++ b/Documentation/rtc.txt
@@ -182,8 +182,8 @@
since the frequency is stored in the irq_freq member of the rtc_device
structure. Your driver needs to initialize the irq_freq member during
init. Make sure you check the requested frequency is in range of your
- hardware in the irq_set_freq function. If you cannot actually change
- the frequency, just return -ENOTTY.
+ hardware in the irq_set_freq function. If it isn't, return -EINVAL. If
+ you cannot actually change the frequency, do not define irq_set_freq.
If all else fails, check out the rtc-test.c driver!