[PATCH 6.18.y 1/2] PCI: imx6: Fix reference clock source selection for i.MX95

[Sasha Levin <sashal@kernel.org>]

From: Franz Schnyder <franz.schnyder@toradex.com>

[ Upstream commit 88cc4cbe08bba27bb58888d25d336774aa0ccab1 ]

In the PCIe PHY init for the i.MX95, the reference clock source selection
uses a conditional instead of always passing the mask. This currently
breaks functionality if the internal refclk is used.

To fix this issue, always pass IMX95_PCIE_REF_USE_PAD as the mask and clear
bit if external refclk is not used. This essentially swaps the parameters.

Fixes: d8574ce57d76 ("PCI: imx6: Add external reference clock input mode support")
Signed-off-by: Franz Schnyder <franz.schnyder@toradex.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Richard Zhu <hongxing.zhu@nxp.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260325093118.684142-1-fra.schnyder@gmail.com
Stable-dep-of: 0c26b1c34d12 ("PCI: imx6: Configure REF_USE_PAD before PHY reset for i.MX95")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/controller/dwc/pci-imx6.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 9083658a4287f7..942fa61d13ef3c 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -150,6 +150,7 @@ struct imx_lut_data {
 struct imx_pcie {
 	struct dw_pcie		*pci;
 	struct gpio_desc	*reset_gpiod;
+	bool			enable_ext_refclk;
 	struct clk_bulk_data	*clks;
 	int			num_clks;
 	struct regmap		*iomuxc_gpr;
@@ -244,6 +245,8 @@ static unsigned int imx_pcie_grp_offset(const struct imx_pcie *imx_pcie)
 
 static int imx95_pcie_init_phy(struct imx_pcie *imx_pcie)
 {
+	bool ext = imx_pcie->enable_ext_refclk;
+
 	/*
 	 * ERR051624: The Controller Without Vaux Cannot Exit L23 Ready
 	 * Through Beacon or PERST# De-assertion
@@ -262,13 +265,12 @@ static int imx95_pcie_init_phy(struct imx_pcie *imx_pcie)
 			IMX95_PCIE_PHY_CR_PARA_SEL,
 			IMX95_PCIE_PHY_CR_PARA_SEL);
 
-	regmap_update_bits(imx_pcie->iomuxc_gpr,
-			   IMX95_PCIE_PHY_GEN_CTRL,
-			   IMX95_PCIE_REF_USE_PAD, 0);
-	regmap_update_bits(imx_pcie->iomuxc_gpr,
-			   IMX95_PCIE_SS_RW_REG_0,
+	regmap_update_bits(imx_pcie->iomuxc_gpr, IMX95_PCIE_PHY_GEN_CTRL,
+			   IMX95_PCIE_REF_USE_PAD,
+			   ext ? IMX95_PCIE_REF_USE_PAD : 0);
+	regmap_update_bits(imx_pcie->iomuxc_gpr, IMX95_PCIE_SS_RW_REG_0,
 			   IMX95_PCIE_REF_CLKEN,
-			   IMX95_PCIE_REF_CLKEN);
+			   ext ? 0 : IMX95_PCIE_REF_CLKEN);
 
 	return 0;
 }
-- 
2.53.0