net: phy: broadcom: Add PTP support for some Broadcom PHYs.

This adds PTP support for BCM54210E Broadcom PHYs, in particular,
the BCM54213PE, as used in the Rasperry PI CM4.  It has only been
tested on that hardware.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/Kconfig

@@ -104,6 +104,8 @@ config AX88796B_PHY
 config BROADCOM_PHY
 	tristate "Broadcom 54XX PHYs"
 	select BCM_NET_PHYLIB
+	select BCM_NET_PHYPTP if NETWORK_PHY_TIMESTAMPING
+	depends on PTP_1588_CLOCK_OPTIONAL
 	help
 	  Currently supports the BCM5411, BCM5421, BCM5461, BCM54616S, BCM5464,
 	  BCM5481, BCM54810 and BCM5482 PHYs.
@@ -160,6 +162,9 @@ config BCM_CYGNUS_PHY
 config BCM_NET_PHYLIB
 	tristate
 
+config BCM_NET_PHYPTP
+	tristate
+
 config CICADA_PHY
 	tristate "Cicada PHYs"
 	help

drivers/net/phy/Makefile

@@ -47,6 +47,7 @@ obj-$(CONFIG_BCM84881_PHY)	+= bcm84881.o
 obj-$(CONFIG_BCM87XX_PHY)	+= bcm87xx.o
 obj-$(CONFIG_BCM_CYGNUS_PHY)	+= bcm-cygnus.o
 obj-$(CONFIG_BCM_NET_PHYLIB)	+= bcm-phy-lib.o
+obj-$(CONFIG_BCM_NET_PHYPTP)	+= bcm-phy-ptp.o
 obj-$(CONFIG_BROADCOM_PHY)	+= broadcom.o
 obj-$(CONFIG_CICADA_PHY)	+= cicada.o
 obj-$(CONFIG_CORTINA_PHY)	+= cortina.o