PCI: dwc: Support 16-lane operation

Some hosts support 16 lanes of PCIe. Make num-lanes accept that number.

Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20250926-topic-pcie_16ln-v1-1-c249acc18790@oss.qualcomm.com

Author: quic-kdybcio

drivers/pci/controller/dwc/pcie-designware.c

@@ -841,6 +841,9 @@ static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes)
 	case 8:
 		plc |= PORT_LINK_MODE_8_LANES;
 		break;
+	case 16:
+		plc |= PORT_LINK_MODE_16_LANES;
+		break;
 	default:
 		dev_err(pci->dev, "num-lanes %u: invalid value\n", num_lanes);
 		return;

drivers/pci/controller/dwc/pcie-designware.h

@@ -90,6 +90,7 @@
 #define PORT_LINK_MODE_2_LANES		PORT_LINK_MODE(0x3)
 #define PORT_LINK_MODE_4_LANES		PORT_LINK_MODE(0x7)
 #define PORT_LINK_MODE_8_LANES		PORT_LINK_MODE(0xf)
+#define PORT_LINK_MODE_16_LANES		PORT_LINK_MODE(0x1f)
 
 #define PCIE_PORT_LANE_SKEW		0x714
 #define PORT_LANE_SKEW_INSERT_MASK	GENMASK(23, 0)