[PATCH v7 3/3] PCI: dwc: Use common speed conversion function

[Hans Zhang]

Replace the private switch-based speed conversion in
dw_pcie_link_set_max_speed() with the public pci_bus_speed2lnkctl2()
function.

This eliminates duplicate conversion logic and ensures consistency with
other PCIe drivers, while handling invalid speeds by falling back to
hardware capabilities.

Signed-off-by: Hans Zhang <18255117159@xxxxxxx>
Reviewed-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
Acked-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-designware.c | 28 +++++++-------------
 1 file changed, 9 insertions(+), 19 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 06792ba92aa7..10895f6a8e6e 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -843,8 +843,10 @@ EXPORT_SYMBOL_GPL(dw_pcie_upconfig_setup);
 
 static void dw_pcie_link_set_max_speed(struct dw_pcie *pci)
 {
-	u32 cap, ctrl2, link_speed;
+	u32 cap, ctrl2;
+	enum pci_bus_speed link_speed;
 	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u16 ctrl2_speed;
 
 	cap = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
 
@@ -861,30 +863,18 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci)
 	ctrl2 = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCTL2);
 	ctrl2 &= ~PCI_EXP_LNKCTL2_TLS;
 
-	switch (pcie_get_link_speed(pci->max_link_speed)) {
-	case PCIE_SPEED_2_5GT:
-		link_speed = PCI_EXP_LNKCTL2_TLS_2_5GT;
-		break;
-	case PCIE_SPEED_5_0GT:
-		link_speed = PCI_EXP_LNKCTL2_TLS_5_0GT;
-		break;
-	case PCIE_SPEED_8_0GT:
-		link_speed = PCI_EXP_LNKCTL2_TLS_8_0GT;
-		break;
-	case PCIE_SPEED_16_0GT:
-		link_speed = PCI_EXP_LNKCTL2_TLS_16_0GT;
-		break;
-	default:
+	link_speed = pcie_get_link_speed(pci->max_link_speed);
+	ctrl2_speed = pci_bus_speed2lnkctl2(link_speed);
+	if (ctrl2_speed == 0) {
 		/* Use hardware capability */
-		link_speed = FIELD_GET(PCI_EXP_LNKCAP_SLS, cap);
+		ctrl2_speed = FIELD_GET(PCI_EXP_LNKCAP_SLS, cap);
 		ctrl2 &= ~PCI_EXP_LNKCTL2_HASD;
-		break;
 	}
 
-	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCTL2, ctrl2 | link_speed);
+	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCTL2, ctrl2 | ctrl2_speed);
 
 	cap &= ~((u32)PCI_EXP_LNKCAP_SLS);
-	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, cap | link_speed);
+	dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, cap | ctrl2_speed);
 
 }
 
-- 
2.34.1