net: stmmac: dwmac-sogfpga: use the lynx pcs driver

dwmac_socfpga re-implements support for the TSE PCS, which is identical
to the already existing TSE PCS, which in turn is the same as the Lynx
PCS. Drop the existing TSE re-implemenation and use the Lynx PCS
instead, relying on the regmap-mdio driver to translate MDIO accesses
into mmio accesses.

Add a lynx_pcs reference in the stmmac's internal structure, and use
.mac_select_pcs() to return the relevant PCS to be used.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/Kconfig

@@ -158,6 +158,9 @@ config DWMAC_SOCFPGA
 	default ARCH_INTEL_SOCFPGA
 	depends on OF && (ARCH_INTEL_SOCFPGA || COMPILE_TEST)
 	select MFD_SYSCON
+	select MDIO_REGMAP
+	select REGMAP_MMIO
+	select PCS_LYNX
 	help
 	  Support for ethernet controller on Altera SOCFPGA
 

drivers/net/ethernet/stmicro/stmmac/Makefile

@@ -35,7 +35,7 @@ obj-$(CONFIG_DWMAC_IMX8)	+= dwmac-imx.o
 obj-$(CONFIG_DWMAC_TEGRA)	+= dwmac-tegra.o
 obj-$(CONFIG_DWMAC_VISCONTI)	+= dwmac-visconti.o
 stmmac-platform-objs:= stmmac_platform.o
-dwmac-altr-socfpga-objs := altr_tse_pcs.o dwmac-socfpga.o
+dwmac-altr-socfpga-objs := dwmac-socfpga.o
 
 obj-$(CONFIG_STMMAC_PCI)	+= stmmac-pci.o
 obj-$(CONFIG_DWMAC_INTEL)	+= dwmac-intel.o

drivers/net/ethernet/stmicro/stmmac/common.h

@@ -16,6 +16,7 @@
 #include <linux/stmmac.h>
 #include <linux/phy.h>
 #include <linux/pcs/pcs-xpcs.h>
+#include <linux/pcs-lynx.h>
 #include <linux/module.h>
 #if IS_ENABLED(CONFIG_VLAN_8021Q)
 #define STMMAC_VLAN_TAG_USED
@@ -519,6 +520,7 @@ struct mac_device_info {
 	const struct stmmac_tc_ops *tc;
 	const struct stmmac_mmc_ops *mmc;
 	struct dw_xpcs *xpcs;
+	struct phylink_pcs *lynx_pcs; /* Lynx external PCS */
 	struct mii_regs mii;	/* MII register Addresses */
 	struct mac_link link;
 	void __iomem *pcsr;     /* vpointer to device CSRs */