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/[e-mail]
Signed-off-by: Frank Li <[e-mail]>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <[e-mail]>
Signed-off-by: Bjorn Helgaas <[e-mail]>
Reviewed-by: Richard Zhu <[e-mail]>
Reviewed-by: Manivannan Sadhasivam <[e-mail]>

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

···
 	IMX8MQ_EP,
 	IMX8MM_EP,
 	IMX8MP_EP,
+	IMX8Q_EP,
 	IMX95_EP,
 };
 
···
 	.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
  * ================================================================================================
···
 		.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 |
···
 	{ .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], },
 	{},
 };