[PATCH V4 07/22] PCI: tegra194: Calibrate P2U for endpoint mode

From: Manikanta Maddireddy

Date: Mon Jan 26 2026 - 02:50:23 EST


From: Vidya Sagar <vidyas@xxxxxxxxxx>

Calibrate P2U for endpoint controller to request UPHY PLL rate change to
Gen1 during initialization. This helps to reset stale PLL state from the
previous bad link state.

Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
Signed-off-by: Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx>
---
V4:
* None

V3:
* Reworded the commit message

V2:
* None

drivers/pci/controller/dwc/pcie-tegra194.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 25f933a578ae..f69bc416b031 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1065,6 +1065,9 @@ static int tegra_pcie_enable_phy(struct tegra_pcie_dw *pcie)
ret = phy_power_on(pcie->phys[i]);
if (ret < 0)
goto phy_exit;
+
+ if (pcie->of_data->mode == DW_PCIE_EP_TYPE)
+ phy_calibrate(pcie->phys[i]);
}

return 0;
--
2.34.1