[PATCH net-next v5 4/4] net: stmmac: dwmac-socfpga: Add support for Agilex5 TSN GMAC with FPGA converter

From: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade-EIB2kfCEclfQT0dZR+AlfA@public.gmane.org>

The Agilex5 SoCDK TSN Config2 board uses a GMII-to-RGMII converter
implemented as FPGA soft IP between gmac1 and its PHY. This converter
provides the RGMII TX/RX clock delays, so the MAC interface selector
must be configured for GMII while the PHY is configured without delays.

Add the "altr,socfpga-stmmac-agilex5-tsn" compatible with dedicated
match .data ops that extend the standard Agilex5 setup: force GMII for
the MAC interface selector and strip delay bits from phy_interface so
the PHY is not configured to add delays already provided by the FPGA
converter.

Signed-off-by: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade-EIB2kfCEclfQT0dZR+AlfA@public.gmane.org>
Reviewed-by: Andrew Lunn <[email protected]>
---
v5: Replace of_device_is_compatible() probe check with dedicated
    socfpga_agilex5_tsn_gmac_ops via match .data, per Krzysztof
    Kozlowski and Dinh Nguyen.
v4: Add Reviewed-by from Andrew Lunn.

 .../ethernet/stmicro/stmmac/dwmac-socfpga.c   | 23 ++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
index 1d7f0a57d288..0632105b420f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
@@ -69,12 +69,13 @@ struct socfpga_dwmac {
 	void __iomem *tse_pcs_base;
 	void __iomem *sgmii_adapter_base;
 	bool f2h_ptp_ref_clk;
+	phy_interface_t mac_interface;
 	const struct socfpga_dwmac_ops *ops;
 };
 
 static phy_interface_t socfpga_get_plat_phymode(struct socfpga_dwmac *dwmac)
 {
-	return dwmac->plat_dat->phy_interface;
+	return dwmac->mac_interface;
 }
 
 static void socfpga_sgmii_config(struct socfpga_dwmac *dwmac, bool enable)
@@ -650,6 +651,8 @@ static int socfpga_dwmac_probe(struct platform_device *pdev)
 	plat_dat->pcs_exit = socfpga_dwmac_pcs_exit;
 	plat_dat->select_pcs = socfpga_dwmac_select_pcs;
 
+	dwmac->mac_interface = plat_dat->phy_interface;
+
 	ops->setup_plat_dat(dwmac);
 
 	return devm_stmmac_pltfr_probe(pdev, plat_dat, &stmmac_res);
@@ -670,10 +673,28 @@ static const struct socfpga_dwmac_ops socfpga_agilex5_ops = {
 	.setup_plat_dat = socfpga_agilex5_setup_plat_dat,
 };
 
+static void socfpga_agilex5_tsn_gmac_setup_plat_dat(struct socfpga_dwmac *dwmac)
+{
+	struct plat_stmmacenet_data *plat_dat = dwmac->plat_dat;
+
+	socfpga_agilex5_setup_plat_dat(dwmac);
+
+	/* FPGA converter supplies RGMII delays; MAC uses GMII, PHY gets plain RGMII */
+	dwmac->mac_interface = PHY_INTERFACE_MODE_GMII;
+	if (phy_interface_mode_is_rgmii(plat_dat->phy_interface))
+		plat_dat->phy_interface = PHY_INTERFACE_MODE_RGMII;
+}
+
+static const struct socfpga_dwmac_ops socfpga_agilex5_tsn_gmac_ops = {
+	.set_phy_mode = socfpga_gen10_set_phy_mode,
+	.setup_plat_dat = socfpga_agilex5_tsn_gmac_setup_plat_dat,
+};
+
 static const struct of_device_id socfpga_dwmac_match[] = {
 	{ .compatible = "altr,socfpga-stmmac", .data = &socfpga_gen5_ops },
 	{ .compatible = "altr,socfpga-stmmac-a10-s10", .data = &socfpga_gen10_ops },
 	{ .compatible = "altr,socfpga-stmmac-agilex5", .data = &socfpga_agilex5_ops },
+	{ .compatible = "altr,socfpga-stmmac-agilex5-tsn", .data = &socfpga_agilex5_tsn_gmac_ops },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, socfpga_dwmac_match);
-- 
2.43.7