[PATCH 6.6.y] PCI: imx6: Fix IMX6SX_GPR12_PCIE_TEST_POWERDOWN handling

[Sasha Levin <sashal@kernel.org>]

From: Richard Zhu <hongxing.zhu@nxp.com>

[ Upstream commit aad953fb4eed0df5486cd54ccad80ac197678e01 ]

The IMX6SX_GPR12_PCIE_TEST_POWERDOWN bit does not control the PCIe
reference clock on i.MX6SX. Instead, it is part of i.MX6SX PCIe core
reset sequence.

Move the IMX6SX_GPR12_PCIE_TEST_POWERDOWN assertion/deassertion into
the core reset functions to properly reflect its purpose. Remove the
.enable_ref_clk() callback for i.MX6SX since it was incorrectly
manipulating this bit.

Fixes: e3c06cd063d6 ("PCI: imx6: Add initial imx6sx support")
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260319090844.444987-1-hongxing.zhu@nxp.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/controller/dwc/pci-imx6.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 23b8dda70cb2f0..c438cf888ad575 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -560,8 +560,6 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
 
 	switch (imx6_pcie->drvdata->variant) {
 	case IMX6SX:
-		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
-				   IMX6SX_GPR12_PCIE_TEST_POWERDOWN, 0);
 		break;
 	case IMX6QP:
 	case IMX6Q:
@@ -733,6 +731,8 @@ static int imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 		imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
 		break;
 	case IMX6SX:
+		regmap_clear_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+				  IMX6SX_GPR12_PCIE_TEST_POWERDOWN);
 		regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
 				   IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
 		break;
-- 
2.53.0