From d1cbfd771ce8297fa11e89f315392de6056a2181 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre <nicolas.pitre@linaro.org> Date: Fri, 11 Nov 2016 00:10:07 -0500 Subject: 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> --- drivers/ptp/Kconfig | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/ptp/Kconfig') diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig index ee3de3421f2d..0f7492f8ea23 100644 --- a/drivers/ptp/Kconfig +++ b/drivers/ptp/Kconfig @@ -28,7 +28,7 @@ config PTP_1588_CLOCK config PTP_1588_CLOCK_GIANFAR tristate "Freescale eTSEC as PTP clock" depends on GIANFAR - select PTP_1588_CLOCK + depends on PTP_1588_CLOCK default y help This driver adds support for using the eTSEC as a PTP @@ -42,7 +42,7 @@ config PTP_1588_CLOCK_GIANFAR config PTP_1588_CLOCK_IXP46X tristate "Intel IXP46x as PTP clock" depends on IXP4XX_ETH - select PTP_1588_CLOCK + depends on PTP_1588_CLOCK default y help This driver adds support for using the IXP46X as a PTP @@ -60,7 +60,7 @@ config DP83640_PHY tristate "Driver for the National Semiconductor DP83640 PHYTER" depends on NETWORK_PHY_TIMESTAMPING depends on PHYLIB - select PTP_1588_CLOCK + depends on PTP_1588_CLOCK ---help--- Supports the DP83640 PHYTER with IEEE 1588 features. @@ -76,7 +76,7 @@ config PTP_1588_CLOCK_PCH tristate "Intel PCH EG20T as PTP clock" depends on X86_32 || COMPILE_TEST depends on HAS_IOMEM && NET - select PTP_1588_CLOCK + 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 -- cgit v1.2.3