ptp: clarify the clock_name sysfs attribute
There has been some confusion among PHC driver authors about the
intended purpose of the clock_name attribute. This patch expands the
documation in order to clarify how the clock_name field should be
understood.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/ABI/testing/sysfs-ptp b/Documentation/ABI/testing/sysfs-ptp
index d40d2b5..05aeedf 100644
--- a/Documentation/ABI/testing/sysfs-ptp
+++ b/Documentation/ABI/testing/sysfs-ptp
@@ -19,7 +19,11 @@
Contact: Richard Cochran <richardcochran@gmail.com>
Description:
This file contains the name of the PTP hardware clock
- as a human readable string.
+ as a human readable string. The purpose of this
+ attribute is to provide the user with a "friendly
+ name" and to help distinguish PHY based devices from
+ MAC based ones. The string does not necessarily have
+ to be any kind of unique id.
What: /sys/class/ptp/ptpN/max_adjustment
Date: September 2010