PCI: imx6: Add i.MX8Q PCIe Endpoint (EP) support

Add support for the i.MX8Q series (i.MX8QM, i.MX8QXP, and i.MX8DXL) PCIe
Endpoint (EP). On the i.MX8Q platforms, the PCI bus addresses differ
from the CPU addresses. However, the DesignWare (DWC) driver already
handles this in the common code.

Link: https://lore.kernel.org/r/20241119-pci_fixup_addr-v8-7-c4bfa5193288@nxp.com
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Richard Zhu <hongxing.zhu@nxp.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Author: nxpfrankli

drivers/pci/controller/dwc/pci-imx6.c

@@ -70,6 +70,7 @@ enum imx_pcie_variants {
 	IMX8MQ_EP,
 	IMX8MM_EP,
 	IMX8MP_EP,
+	IMX8Q_EP,
 	IMX95_EP,
 };
 
@@ -1082,6 +1083,16 @@ static const struct pci_epc_features imx8m_pcie_epc_features = {
 	.align = SZ_64K,
 };
 
+static const struct pci_epc_features imx8q_pcie_epc_features = {
+	.linkup_notifier = false,
+	.msi_capable = true,
+	.msix_capable = false,
+	.bar[BAR_1] = { .type = BAR_RESERVED, },
+	.bar[BAR_3] = { .type = BAR_RESERVED, },
+	.bar[BAR_5] = { .type = BAR_RESERVED, },
+	.align = SZ_64K,
+};
+
 /*
  * BAR#	| Default BAR enable	| Default BAR Type	| Default BAR Size	| BAR Sizing Scheme
  * ================================================================================================
@@ -1678,6 +1689,14 @@ static const struct imx_pcie_drvdata drvdata[] = {
 		.epc_features = &imx8m_pcie_epc_features,
 		.enable_ref_clk = imx8mm_pcie_enable_ref_clk,
 	},
+	[IMX8Q_EP] = {
+		.variant = IMX8Q_EP,
+		.flags = IMX_PCIE_FLAG_HAS_PHYDRV,
+		.mode = DW_PCIE_EP_TYPE,
+		.epc_features = &imx8q_pcie_epc_features,
+		.clk_names = imx8q_clks,
+		.clks_cnt = ARRAY_SIZE(imx8q_clks),
+	},
 	[IMX95_EP] = {
 		.variant = IMX95_EP,
 		.flags = IMX_PCIE_FLAG_HAS_SERDES |
@@ -1707,6 +1726,7 @@ static const struct of_device_id imx_pcie_of_match[] = {
 	{ .compatible = "fsl,imx8mq-pcie-ep", .data = &drvdata[IMX8MQ_EP], },
 	{ .compatible = "fsl,imx8mm-pcie-ep", .data = &drvdata[IMX8MM_EP], },
 	{ .compatible = "fsl,imx8mp-pcie-ep", .data = &drvdata[IMX8MP_EP], },
+	{ .compatible = "fsl,imx8q-pcie-ep", .data = &drvdata[IMX8Q_EP], },
 	{ .compatible = "fsl,imx95-pcie-ep", .data = &drvdata[IMX95_EP], },
 	{},
 };