linux-stable/drivers/ptp/Kconfig
Nicolas Pitre d1cbfd771c ptp_clock: Allow for it to be optional
In order to break the hard dependency between the PTP clock subsystem and
ethernet drivers capable of being clock providers, this patch provides
simple PTP stub functions to allow linkage of those drivers into the
kernel even when the PTP subsystem is configured out. Drivers must be
ready to accept NULL from ptp_clock_register() in that case.

And to make it possible for PTP to be configured out, the select statement
in those driver's Kconfig menu entries is converted to the new "imply"
statement. This way the PTP subsystem may have Kconfig dependencies of
its own, such as POSIX_TIMERS, without having to make those ethernet
drivers unavailable if POSIX timers are cconfigured out. And when support
for POSIX timers is selected again then the default config option for PTP
clock support will automatically be adjusted accordingly.

The pch_gbe driver is a bit special as it relies on extra code in
drivers/ptp/ptp_pch.c. Therefore we let the make process descend into
drivers/ptp/ even if PTP_1588_CLOCK is unselected.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Edward Cree <ecree@solarflare.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-kbuild@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Michal Marek <mmarek@suse.com>
Link: http://lkml.kernel.org/r/1478841010-28605-4-git-send-email-nicolas.pitre@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-16 09:26:34 +01:00

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#
# PTP clock support configuration
#
menu "PTP clock support"
config PTP_1588_CLOCK
tristate "PTP clock support"
depends on NET
select PPS
select NET_PTP_CLASSIFY
help
The IEEE 1588 standard defines a method to precisely
synchronize distributed clocks over Ethernet networks. The
standard defines a Precision Time Protocol (PTP), which can
be used to achieve synchronization within a few dozen
microseconds. In addition, with the help of special hardware
time stamping units, it can be possible to achieve
synchronization to within a few hundred nanoseconds.
This driver adds support for PTP clocks as character
devices. If you want to use a PTP clock, then you should
also enable at least one clock driver as well.
To compile this driver as a module, choose M here: the module
will be called ptp.
config PTP_1588_CLOCK_GIANFAR
tristate "Freescale eTSEC as PTP clock"
depends on GIANFAR
depends on PTP_1588_CLOCK
default y
help
This driver adds support for using the eTSEC as a PTP
clock. This clock is only useful if your PTP programs are
getting hardware time stamps on the PTP Ethernet packets
using the SO_TIMESTAMPING API.
To compile this driver as a module, choose M here: the module
will be called gianfar_ptp.
config PTP_1588_CLOCK_IXP46X
tristate "Intel IXP46x as PTP clock"
depends on IXP4XX_ETH
depends on PTP_1588_CLOCK
default y
help
This driver adds support for using the IXP46X as a PTP
clock. This clock is only useful if your PTP programs are
getting hardware time stamps on the PTP Ethernet packets
using the SO_TIMESTAMPING API.
To compile this driver as a module, choose M here: the module
will be called ptp_ixp46x.
comment "Enable PHYLIB and NETWORK_PHY_TIMESTAMPING to see the additional clocks."
depends on PHYLIB=n || NETWORK_PHY_TIMESTAMPING=n
config DP83640_PHY
tristate "Driver for the National Semiconductor DP83640 PHYTER"
depends on NETWORK_PHY_TIMESTAMPING
depends on PHYLIB
depends on PTP_1588_CLOCK
---help---
Supports the DP83640 PHYTER with IEEE 1588 features.
This driver adds support for using the DP83640 as a PTP
clock. This clock is only useful if your PTP programs are
getting hardware time stamps on the PTP Ethernet packets
using the SO_TIMESTAMPING API.
In order for this to work, your MAC driver must also
implement the skb_tx_timestamp() function.
config PTP_1588_CLOCK_PCH
tristate "Intel PCH EG20T as PTP clock"
depends on X86_32 || COMPILE_TEST
depends on HAS_IOMEM && NET
imply PTP_1588_CLOCK
help
This driver adds support for using the PCH EG20T as a PTP
clock. The hardware supports time stamping of PTP packets
when using the end-to-end delay (E2E) mechansim. The peer
delay mechansim (P2P) is not supported.
This clock is only useful if your PTP programs are getting
hardware time stamps on the PTP Ethernet packets using the
SO_TIMESTAMPING API.
To compile this driver as a module, choose M here: the module
will be called ptp_pch.
endmenu