Merge branches 'for-3.15/upstream-fixes' and 'for-3.16/upstream' into for-linus

Conflicts:
	drivers/hid/hid-sensor-hub.c

9 files changed, 432 insertions, 25 deletions

diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram
index 3f0b9ae61d8..70ec992514d 100644
--- a/Documentation/ABI/testing/sysfs-block-zram
+++ b/Documentation/ABI/testing/sysfs-block-zram
@@ -43,6 +43,36 @@ Description:
 		The invalid_io file is read-only and specifies the number of
 		non-page-size-aligned I/O requests issued to this device.
 
+What:		/sys/block/zram<id>/failed_reads
+Date:		February 2014
+Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
+Description:
+		The failed_reads file is read-only and specifies the number of
+		failed reads happened on this device.
+
+What:		/sys/block/zram<id>/failed_writes
+Date:		February 2014
+Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
+Description:
+		The failed_writes file is read-only and specifies the number of
+		failed writes happened on this device.
+
+What:		/sys/block/zram<id>/max_comp_streams
+Date:		February 2014
+Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
+Description:
+		The max_comp_streams file is read-write and specifies the
+		number of backend's zcomp_strm compression streams (number of
+		concurrent compress operations).
+
+What:		/sys/block/zram<id>/comp_algorithm
+Date:		February 2014
+Contact:	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
+Description:
+		The comp_algorithm file is read-write and lets to show
+		available and selected compression algorithms, change
+		compression algorithm selection.
+
 What:		/sys/block/zram<id>/notify_free
 Date:		August 2010
 Contact:	Nitin Gupta <ngupta@vflare.org>
@@ -53,15 +83,6 @@ Description:
 		is freed. This statistic is applicable only when this disk is
 		being used as a swap disk.
 
-What:		/sys/block/zram<id>/discard
-Date:		August 2010
-Contact:	Nitin Gupta <ngupta@vflare.org>
-Description:
-		The discard file is read-only and specifies the number of
-		discard requests received by this device. These requests
-		provide information to block device regarding blocks which are
-		no longer used by filesystem.
-
 What:		/sys/block/zram<id>/zero_pages
 Date:		August 2010
 Contact:	Nitin Gupta <ngupta@vflare.org>
diff --git a/Documentation/ABI/testing/sysfs-bus-mdio b/Documentation/ABI/testing/sysfs-bus-mdio
index 6349749ebc2..491baaf4285 100644
--- a/Documentation/ABI/testing/sysfs-bus-mdio
+++ b/Documentation/ABI/testing/sysfs-bus-mdio
@@ -7,3 +7,23 @@ Description:
 		by the device during bus enumeration, encoded in hexadecimal.
 		This ID is used to match the device with the appropriate
 		driver.
+
+What:		/sys/bus/mdio_bus/devices/.../phy_interface
+Date:		February 2014
+KernelVersion:	3.15
+Contact:	netdev@vger.kernel.org
+Description:
+		This attribute contains the PHY interface as configured by the
+		Ethernet driver during bus enumeration, encoded in string.
+		This interface mode is used to configure the Ethernet MAC with the
+		appropriate mode for its data lines to the PHY hardware.
+
+What:		/sys/bus/mdio_bus/devices/.../phy_has_fixups
+Date:		February 2014
+KernelVersion:	3.15
+Contact:	netdev@vger.kernel.org
+Description:
+		This attribute contains the boolean value whether a given PHY
+		device has had any "fixup" workaround running on it, encoded as
+		a boolean. This information is provided to help troubleshooting
+		PHY configurations.
diff --git a/Documentation/ABI/testing/sysfs-class-net b/Documentation/ABI/testing/sysfs-class-net
new file mode 100644
index 00000000000..d922060e455
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-net
@@ -0,0 +1,199 @@
+What:		/sys/class/net/<iface>/addr_assign_type
+Date:		July 2010
+KernelVersion:	3.2
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the address assignment type. Possible values are:
+		0: permanent address
+		1: randomly generated
+		2: stolen from another device
+		3: set using dev_set_mac_address
+
+What:		/sys/class/net/<iface>/addr_len
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the hardware address size in bytes.
+		Values vary based on the lower-level protocol used by the
+		interface (Ethernet, FDDI, ATM, IEEE 802.15.4...). See
+		include/uapi/linux/if_*.h for actual values.
+
+What:		/sys/class/net/<iface>/address
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Hardware address currently assigned to this interface.
+		Format is a string, e.g: 00:11:22:33:44:55 for an Ethernet MAC
+		address.
+
+What:		/sys/class/net/<iface>/broadcast
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Hardware broadcast address for this interface. Format is a
+		string, e.g: ff:ff:ff:ff:ff:ff for an Ethernet broadcast MAC
+		address.
+
+What:		/sys/class/net/<iface>/carrier
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the current physical link state of the interface.
+		Posssible values are:
+		0: physical link is down
+		1: physical link is up
+
+		Note: some special devices, e.g: bonding and team drivers will
+		allow this attribute to be written to force a link state for
+		operating correctly and designating another fallback interface.
+
+What:		/sys/class/net/<iface>/dev_id
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the device unique identifier. Format is an hexadecimal
+		value. This is used to disambiguate interfaces which might be
+		stacked (e.g: VLAN interfaces) but still have the same MAC
+		address as their parent device.
+
+What:		/sys/class/net/<iface>/dormant
+Date:		March 2006
+KernelVersion:	2.6.17
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates whether the interface is in dormant state. Possible
+		values are:
+		0: interface is not dormant
+		1: interface is dormant
+
+		This attribute can be used by supplicant software to signal that
+		the device is not usable unless some supplicant-based
+		authentication is performed (e.g: 802.1x). 'link_mode' attribute
+		will also reflect the dormant state.
+
+What:		/sys/clas/net/<iface>/duplex
+Date:		October 2009
+KernelVersion:	2.6.33
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the interface latest or current duplex value. Possible
+		values are:
+		half: half duplex
+		full: full duplex
+
+		Note: This attribute is only valid for interfaces that implement
+		the ethtool get_settings method (mostly Ethernet).
+
+What:		/sys/class/net/<iface>/flags
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the interface flags as a bitmask in hexadecimal. See
+		include/uapi/linux/if.h for a list of all possible values and
+		the flags semantics.
+
+What:		/sys/class/net/<iface>/ifalias
+Date:		September 2008
+KernelVersion:	2.6.28
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates/stores an interface alias name as a string. This can
+		be used for system management purposes.
+
+What:		/sys/class/net/<iface>/ifindex
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the system-wide interface unique index identifier as a
+		decimal number. This attribute is used for mapping an interface
+		identifier to an interface name. It is used throughout the
+		networking stack for specifying the interface specific
+		requests/events.
+
+What:		/sys/class/net/<iface>/iflink
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the system-wide interface unique index identifier a
+		the interface is linked to. Format is decimal. This attribute is
+		used to resolve interfaces chaining, linking and stacking.
+		Physical interfaces have the same 'ifindex' and 'iflink' values.
+
+What:		/sys/class/net/<iface>/link_mode
+Date:		March 2006
+KernelVersion:	2.6.17
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the interface link mode, as a decimal number. This
+		attribute should be used in conjunction with 'dormant' attribute
+		to determine the interface usability. Possible values:
+		0: default link mode
+		1: dormant link mode
+
+What:		/sys/class/net/<iface>/mtu
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the interface currently configured MTU value, in
+		bytes, and in decimal format. Specific values depends on the
+		lower-level interface protocol used. Ethernet devices will show
+		a 'mtu' attribute value of 1500 unless changed.
+
+What:		/sys/calss/net/<iface>/netdev_group
+Date:		January 2011
+KernelVersion:	2.6.39
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the interface network device group, as a decimal
+		integer. Default value is 0 which corresponds to the initial
+		network devices group. The group can be changed to affect
+		routing decisions (see: net/ipv4/fib_rules and
+		net/ipv6/fib6_rules.c).
+
+What:		/sys/class/net/<iface>/operstate
+Date:		March 2006
+KernelVersion:	2.6.17
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the interface RFC2863 operational state as a string.
+		Possible values are:
+		"unknown", "notpresent", "down", "lowerlayerdown", "testing",
+		"dormant", "up".
+
+What:		/sys/class/net/<iface>/speed
+Date:		October 2009
+KernelVersion:	2.6.33
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the interface latest or current speed value. Value is
+		an integer representing the link speed in Mbits/sec.
+
+		Note: this attribute is only valid for interfaces that implement
+		the ethtool get_settings method (mostly Ethernet ).
+
+What:		/sys/class/net/<iface>/tx_queue_len
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the interface transmit queue len in number of packets,
+		as an integer value. Value depend on the type of interface,
+		Ethernet network adapters have a default value of 1000 unless
+		configured otherwise
+
+What:		/sys/class/net/<iface>/type
+Date:		April 2005
+KernelVersion:	2.6.12
+Contact:	netdev@vger.kernel.org
+Description:
+		Indicates the interface protocol type as a decimal value. See
+		include/uapi/linux/if_arp.h for all possible values.
diff --git a/Documentation/ABI/testing/sysfs-class-net-mesh b/Documentation/ABI/testing/sysfs-class-net-mesh
index 4793d3dff6a..c4640629663 100644
--- a/Documentation/ABI/testing/sysfs-class-net-mesh
+++ b/Documentation/ABI/testing/sysfs-class-net-mesh
@@ -76,6 +76,15 @@ Description:
 		is used to classify clients as "isolated" by the
 		Extended Isolation feature.
 
+What:           /sys/class/net/<mesh_iface>/mesh/multicast_mode
+Date:           Feb 2014
+Contact:        Linus Lüssing <linus.luessing@web.de>
+Description:
+                Indicates whether multicast optimizations are enabled
+                or disabled. If set to zero then all nodes in the
+                mesh are going to use classic flooding for any
+                multicast packet with no optimizations.
+
 What:           /sys/class/net/<mesh_iface>/mesh/network_coding
 Date:           Nov 2012
 Contact:        Martin Hundeboll <martin@hundeboll.net>
diff --git a/Documentation/ABI/testing/sysfs-class-rc b/Documentation/ABI/testing/sysfs-class-rc
new file mode 100644
index 00000000000..b65674da43b
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-rc
@@ -0,0 +1,111 @@
+What:		/sys/class/rc/
+Date:		Apr 2010
+KernelVersion:	2.6.35
+Contact:	Mauro Carvalho Chehab <m.chehab@samsung.com>
+Description:
+		The rc/ class sub-directory belongs to the Remote Controller
+		core and provides a sysfs interface for configuring infrared
+		remote controller receivers.
+
+What:		/sys/class/rc/rcN/
+Date:		Apr 2010
+KernelVersion:	2.6.35
+Contact:	Mauro Carvalho Chehab <m.chehab@samsung.com>
+Description:
+		A /sys/class/rc/rcN directory is created for each remote
+		control receiver device where N is the number of the receiver.
+
+What:		/sys/class/rc/rcN/protocols
+Date:		Jun 2010
+KernelVersion:	2.6.36
+Contact:	Mauro Carvalho Chehab <m.chehab@samsung.com>
+Description:
+		Reading this file returns a list of available protocols,
+		something like:
+		    "rc5 [rc6] nec jvc [sony]"
+		Enabled protocols are shown in [] brackets.
+		Writing "+proto" will add a protocol to the list of enabled
+		protocols.
+		Writing "-proto" will remove a protocol from the list of enabled
+		protocols.
+		Writing "proto" will enable only "proto".
+		Writing "none" will disable all protocols.
+		Write fails with EINVAL if an invalid protocol combination or
+		unknown protocol name is used.
+
+What:		/sys/class/rc/rcN/filter
+Date:		Jan 2014
+KernelVersion:	3.15
+Contact:	Mauro Carvalho Chehab <m.chehab@samsung.com>
+Description:
+		Sets the scancode filter expected value.
+		Use in combination with /sys/class/rc/rcN/filter_mask to set the
+		expected value of the bits set in the filter mask.
+		If the hardware supports it then scancodes which do not match
+		the filter will be ignored. Otherwise the write will fail with
+		an error.
+		This value may be reset to 0 if the current protocol is altered.
+
+What:		/sys/class/rc/rcN/filter_mask
+Date:		Jan 2014
+KernelVersion:	3.15
+Contact:	Mauro Carvalho Chehab <m.chehab@samsung.com>
+Description:
+		Sets the scancode filter mask of bits to compare.
+		Use in combination with /sys/class/rc/rcN/filter to set the bits
+		of the scancode which should be compared against the expected
+		value. A value of 0 disables the filter to allow all valid
+		scancodes to be processed.
+		If the hardware supports it then scancodes which do not match
+		the filter will be ignored. Otherwise the write will fail with
+		an error.
+		This value may be reset to 0 if the current protocol is altered.
+
+What:		/sys/class/rc/rcN/wakeup_protocols
+Date:		Feb 2014
+KernelVersion:	3.15
+Contact:	Mauro Carvalho Chehab <m.chehab@samsung.com>
+Description:
+		Reading this file returns a list of available protocols to use
+		for the wakeup filter, something like:
+		    "rc5 rc6 nec jvc [sony]"
+		The enabled wakeup protocol is shown in [] brackets.
+		Writing "+proto" will add a protocol to the list of enabled
+		wakeup protocols.
+		Writing "-proto" will remove a protocol from the list of enabled
+		wakeup protocols.
+		Writing "proto" will use "proto" for wakeup events.
+		Writing "none" will disable wakeup.
+		Write fails with EINVAL if an invalid protocol combination or
+		unknown protocol name is used, or if wakeup is not supported by
+		the hardware.
+
+What:		/sys/class/rc/rcN/wakeup_filter
+Date:		Jan 2014
+KernelVersion:	3.15
+Contact:	Mauro Carvalho Chehab <m.chehab@samsung.com>
+Description:
+		Sets the scancode wakeup filter expected value.
+		Use in combination with /sys/class/rc/rcN/wakeup_filter_mask to
+		set the expected value of the bits set in the wakeup filter mask
+		to trigger a system wake event.
+		If the hardware supports it and wakeup_filter_mask is not 0 then
+		scancodes which match the filter will wake the system from e.g.
+		suspend to RAM or power off.
+		Otherwise the write will fail with an error.
+		This value may be reset to 0 if the wakeup protocol is altered.
+
+What:		/sys/class/rc/rcN/wakeup_filter_mask
+Date:		Jan 2014
+KernelVersion:	3.15
+Contact:	Mauro Carvalho Chehab <m.chehab@samsung.com>
+Description:
+		Sets the scancode wakeup filter mask of bits to compare.
+		Use in combination with /sys/class/rc/rcN/wakeup_filter to set
+		the bits of the scancode which should be compared against the
+		expected value to trigger a system wake event.
+		If the hardware supports it and wakeup_filter_mask is not 0 then
+		scancodes which match the filter will wake the system from e.g.
+		suspend to RAM or power off.
+		Otherwise the write will fail with an error.
+		This value may be reset to 0 if the wakeup protocol is altered.
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power
index 7dbf96b724e..676fdf5f2a9 100644
--- a/Documentation/ABI/testing/sysfs-devices-power
+++ b/Documentation/ABI/testing/sysfs-devices-power
@@ -83,8 +83,10 @@ Contact:	Rafael J. Wysocki <rjw@rjwysocki.net>
 Description:
 		The /sys/devices/.../wakeup_count attribute contains the number
 		of signaled wakeup events associated with the device.  This
-		attribute is read-only.  If the device is not enabled to wake up
+		attribute is read-only.  If the device is not capable to wake up
 		the system from sleep states, this attribute is not present.
+		If the device is not enabled to wake up the system from sleep
+		states, this attribute is empty.
 
 What:		/sys/devices/.../power/wakeup_active_count
 Date:		September 2010
@@ -93,8 +95,10 @@ Description:
 		The /sys/devices/.../wakeup_active_count attribute contains the
 		number of times the processing of wakeup events associated with
 		the device was completed (at the kernel level).  This attribute
-		is read-only.  If the device is not enabled to wake up the
-		system from sleep states, this attribute is not present.
+		is read-only.  If the device is not capable to wake up the
+		system from sleep states, this attribute is not present.  If
+		the device is not enabled to wake up the system from sleep
+		states, this attribute is empty.
 
 What:		/sys/devices/.../power/wakeup_abort_count
 Date:		February 2012
@@ -104,8 +108,9 @@ Description:
 		number of times the processing of a wakeup event associated with
 		the device might have aborted system transition into a sleep
 		state in progress.  This attribute is read-only.  If the device
-		is not enabled to wake up the system from sleep states, this
-		attribute is not present.
+		is not capable to wake up the system from sleep states, this
+		attribute is not present.  If the device is not enabled to wake
+		up the system from sleep states, this attribute is empty.
 
 What:		/sys/devices/.../power/wakeup_expire_count
 Date:		February 2012
@@ -114,8 +119,10 @@ Description:
 		The /sys/devices/.../wakeup_expire_count attribute contains the
 		number of times a wakeup event associated with the device has
 		been reported with a timeout that expired.  This attribute is
-		read-only.  If the device is not enabled to wake up the system
-		from sleep states, this attribute is not present.
+		read-only.  If the device is not capable to wake up the system
+		from sleep states, this attribute is not present.  If the
+		device is not enabled to wake up the system from sleep states,
+		this attribute is empty.
 
 What:		/sys/devices/.../power/wakeup_active
 Date:		September 2010
@@ -124,8 +131,10 @@ Description:
 		The /sys/devices/.../wakeup_active attribute contains either 1,
 		or 0, depending on whether or not a wakeup event associated with
 		the device is being processed (1).  This attribute is read-only.
-		If the device is not enabled to wake up the system from sleep
-		states, this attribute is not present.
+		If the device is not capable to wake up the system from sleep
+		states, this attribute is not present.  If the device is not
+		enabled to wake up the system from sleep states, this attribute
+		is empty.
 
 What:		/sys/devices/.../power/wakeup_total_time_ms
 Date:		September 2010
@@ -134,8 +143,9 @@ Description:
 		The /sys/devices/.../wakeup_total_time_ms attribute contains
 		the total time of processing wakeup events associated with the
 		device, in milliseconds.  This attribute is read-only.  If the
-		device is not enabled to wake up the system from sleep states,
-		this attribute is not present.
+		device is not capable to wake up the system from sleep states,
+		this attribute is not present.  If the device is not enabled to
+		wake up the system from sleep states, this attribute is empty.
 
 What:		/sys/devices/.../power/wakeup_max_time_ms
 Date:		September 2010
@@ -144,8 +154,10 @@ Description:
 		The /sys/devices/.../wakeup_max_time_ms attribute contains
 		the maximum time of processing a single wakeup event associated
 		with the device, in milliseconds.  This attribute is read-only.
-		If the device is not enabled to wake up the system from sleep
-		states, this attribute is not present.
+		If the device is not capable to wake up the system from sleep
+		states, this attribute is not present.  If the device is not
+		enabled to wake up the system from sleep states, this attribute
+		is empty.
 
 What:		/sys/devices/.../power/wakeup_last_time_ms
 Date:		September 2010
@@ -156,7 +168,8 @@ Description:
 		signaling the last wakeup event associated with the device, in
 		milliseconds.  This attribute is read-only.  If the device is
 		not enabled to wake up the system from sleep states, this
-		attribute is not present.
+		attribute is not present.  If the device is not enabled to wake
+		up the system from sleep states, this attribute is empty.
 
 What:		/sys/devices/.../power/wakeup_prevent_sleep_time_ms
 Date:		February 2012
@@ -165,9 +178,10 @@ Description:
 		The /sys/devices/.../wakeup_prevent_sleep_time_ms attribute
 		contains the total time the device has been preventing
 		opportunistic transitions to sleep states from occurring.
-		This attribute is read-only.  If the device is not enabled to
+		This attribute is read-only.  If the device is not capable to
 		wake up the system from sleep states, this attribute is not
-		present.
+		present.  If the device is not enabled to wake up the system
+		from sleep states, this attribute is empty.
 
 What:		/sys/devices/.../power/autosuspend_delay_ms
 Date:		September 2010
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 32b0809203d..62dd72522d6 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -55,3 +55,15 @@ Date:		January 2014
 Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
 Description:
 		 Controls the number of trials to find a victim segment.
+
+What:		/sys/fs/f2fs/<disk>/dir_level
+Date:		March 2014
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the directory level for large directory.
+
+What:		/sys/fs/f2fs/<disk>/ram_thresh
+Date:		March 2014
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the memory footprint used by f2fs.
diff --git a/Documentation/ABI/testing/sysfs-module b/Documentation/ABI/testing/sysfs-module
index 47064c2b1f7..0aac02e7fb0 100644
--- a/Documentation/ABI/testing/sysfs-module
+++ b/Documentation/ABI/testing/sysfs-module
@@ -49,3 +49,4 @@ Description:	Module taint flags:
 			O - out-of-tree module
 			F - force-loaded module
 			C - staging driver module
+			E - unsigned module
diff --git a/Documentation/ABI/testing/sysfs-ptp b/Documentation/ABI/testing/sysfs-ptp
index 05aeedf1779..44806a678f1 100644
--- a/Documentation/ABI/testing/sysfs-ptp
+++ b/Documentation/ABI/testing/sysfs-ptp
@@ -54,6 +54,26 @@ Description:
 		This file contains the number of programmable periodic
 		output channels offered by the PTP hardware clock.
 
+What:		/sys/class/ptp/ptpN/n_pins
+Date:		March 2014
+Contact:	Richard Cochran <richardcochran@gmail.com>
+Description:
+		This file contains the number of programmable pins
+		offered by the PTP hardware clock.
+
+What:		/sys/class/ptp/ptpN/pins
+Date:		March 2014
+Contact:	Richard Cochran <richardcochran@gmail.com>
+Description:
+		This directory contains one file for each programmable
+		pin offered by the PTP hardware clock. The file name
+		is the hardware dependent pin name. Reading from this
+		file produces two numbers, the assigned function (see
+		the PTP_PF_ enumeration values in linux/ptp_clock.h)
+		and the channel number. The function and channel
+		assignment may be changed by two writing numbers into
+		the file.
+
 What:		/sys/class/ptp/ptpN/pps_avaiable
 Date:		September 2010
 Contact:	Richard Cochran <richardcochran@gmail.com>