[PATCH net-next v2 5/6] stmmac: intel: add phy-mode ACPI _DSD setting support

[Ong Boon Leong <boon.leong.ong@intel.com>]

Currently, phy_interface for TSN controller instance is set based on its
PCI Device ID. For SGMII PHY interface, phy_interface default to
PHY_INTERFACE_MODE_SGMII. As C37 AN supports both SGMII and 1000BASE-X
mode, we add support for 'phy-mode' ACPI _DSD for port-specific
and customer platform specific customization.

Thanks to Andrew Lunn's guidance in
https://patchwork.kernel.org/comment/24827101/

Tested-by: Emilio Riva <emilio.riva@ericsson.com>
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
index 675dfb89b76..e5f3d7deec3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
@@ -442,6 +442,7 @@ static void common_default_data(struct plat_stmmacenet_data *plat)
 static int intel_mgbe_common_data(struct pci_dev *pdev,
 				  struct plat_stmmacenet_data *plat)
 {
+	struct fwnode_handle *fwnode;
 	char clk_name[20];
 	int ret;
 	int i;
@@ -560,6 +561,20 @@ static int intel_mgbe_common_data(struct pci_dev *pdev,
 	/* Use the last Rx queue */
 	plat->vlan_fail_q = plat->rx_queues_to_use - 1;
 
+	/* For fixed-link setup, we allow phy-mode setting */
+	fwnode = dev_fwnode(&pdev->dev);
+	if (fwnode) {
+		const char *phy_mode;
+
+		if (!fwnode_property_read_string(fwnode, "phy-mode",
+						 &phy_mode)) {
+			if (!strcmp(phy_mode, "sgmii"))
+				plat->phy_interface = PHY_INTERFACE_MODE_SGMII;
+			if (!strcmp(phy_mode, "1000base-x"))
+				plat->phy_interface = PHY_INTERFACE_MODE_1000BASEX;
+		}
+	}
+
 	/* Intel mgbe SGMII interface uses pcs-xcps */
 	if (plat->phy_interface == PHY_INTERFACE_MODE_SGMII ||
 	    plat->phy_interface == PHY_INTERFACE_MODE_1000BASEX) {
-- 
2.25.1