[PATCH v4 12/12] PCI: imx6: Add i.MX8Q PCIe root complex (RC) support

[Frank Li <Frank.Li@xxxxxxx>]

From: Richard Zhu <hongxing.zhu@xxxxxxx>

Implement i.MX8Q (i.MX8QM, i.MX8QXP, and i.MX8DXL) PCIe RC support. While
the controller resembles that of iMX8MP, the PHY differs significantly.
Notably, there's a distinction between PCI bus addresses and CPU addresses.

Introduce IMX_PCIE_FLAG_CPU_ADDR_FIXUP in drvdata::flags to indicate driver
need the cpu_addr_fixup() callback to facilitate CPU address to PCI bus
address conversion according to "range" property.

Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
 drivers/pci/controller/dwc/pci-imx6.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index df623977d8fe6..a5af3e874613d 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -82,6 +82,7 @@ enum imx_pcie_variants {
 	IMX8MQ,
 	IMX8MM,
 	IMX8MP,
+	IMX8Q,
 	IMX95,
 	IMX8MQ_EP,
 	IMX8MM_EP,
@@ -98,6 +99,7 @@ enum imx_pcie_variants {
 #define IMX_PCIE_FLAG_HAS_SERDES		BIT(6)
 #define IMX_PCIE_FLAG_SUPPORT_64BIT		BIT(7)
 #define IMX_PCIE_FLAG_MONITOR_DEV		BIT(8)
+#define IMX_PCIE_FLAG_CPU_ADDR_FIXUP		BIT(9)
 
 #define imx_check_flag(pci, val)     (pci->drvdata->flags & val)
 
@@ -1091,6 +1093,22 @@ static void imx_pcie_host_exit(struct dw_pcie_rp *pp)
 		regulator_disable(imx_pcie->vpcie);
 }
 
+static u64 imx_pcie_cpu_addr_fixup(struct dw_pcie *pcie, u64 cpu_addr)
+{
+	struct imx_pcie *imx_pcie = to_imx_pcie(pcie);
+	struct dw_pcie_rp *pp = &pcie->pp;
+	struct resource_entry *entry;
+	unsigned int offset;
+
+	if (!(imx_pcie->drvdata->flags & IMX_PCIE_FLAG_CPU_ADDR_FIXUP))
+		return cpu_addr;
+
+	entry = resource_list_first_type(&pp->bridge->windows, IORESOURCE_MEM);
+	offset = entry->offset;
+
+	return (cpu_addr - offset);
+}
+
 static const struct dw_pcie_host_ops imx_pcie_host_ops = {
 	.init = imx_pcie_host_init,
 	.deinit = imx_pcie_host_exit,
@@ -1099,6 +1117,7 @@ static const struct dw_pcie_host_ops imx_pcie_host_ops = {
 static const struct dw_pcie_ops dw_pcie_ops = {
 	.start_link = imx_pcie_start_link,
 	.stop_link = imx_pcie_stop_link,
+	.cpu_addr_fixup = imx_pcie_cpu_addr_fixup,
 };
 
 static void imx_pcie_ep_init(struct dw_pcie_ep *ep)
@@ -1599,6 +1618,13 @@ static int imx_pcie_probe(struct platform_device *pdev)
 		if (ret < 0)
 			return ret;
 
+		if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_CPU_ADDR_FIXUP)) {
+			if (!resource_list_first_type(&pci->pp.bridge->windows, IORESOURCE_MEM)) {
+				dw_pcie_host_deinit(&pci->pp);
+				return dev_err_probe(dev, -EINVAL, "DTS Miss PCI memory range");
+			}
+		}
+
 		if (pci_msi_enabled()) {
 			u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
 
@@ -1623,6 +1649,7 @@ static const char * const imx6q_clks[] = {"pcie_bus", "pcie", "pcie_phy"};
 static const char * const imx8mm_clks[] = {"pcie_bus", "pcie", "pcie_aux"};
 static const char * const imx8mq_clks[] = {"pcie_bus", "pcie", "pcie_phy", "pcie_aux"};
 static const char * const imx6sx_clks[] = {"pcie_bus", "pcie", "pcie_phy", "pcie_inbound_axi"};
+static const char * const imx8q_clks[] = {"mstr", "slv", "dbi"};
 
 static const struct imx_pcie_drvdata drvdata[] = {
 	[IMX6Q] = {
@@ -1726,6 +1753,13 @@ static const struct imx_pcie_drvdata drvdata[] = {
 		.mode_mask[0] = IMX6Q_GPR12_DEVICE_TYPE,
 		.set_ref_clk = imx8mm_pcie_set_ref_clk,
 	},
+	[IMX8Q] = {
+		.variant = IMX8Q,
+		.flags = IMX_PCIE_FLAG_HAS_PHYDRV |
+			 IMX_PCIE_FLAG_CPU_ADDR_FIXUP,
+		.clk_names = imx8q_clks,
+		.clks_cnt = ARRAY_SIZE(imx8q_clks),
+	},
 	[IMX95] = {
 		.variant = IMX95,
 		.flags = IMX_PCIE_FLAG_HAS_SERDES |
@@ -1804,6 +1838,7 @@ static const struct of_device_id imx_pcie_of_match[] = {
 	{ .compatible = "fsl,imx8mq-pcie", .data = &drvdata[IMX8MQ], },
 	{ .compatible = "fsl,imx8mm-pcie", .data = &drvdata[IMX8MM], },
 	{ .compatible = "fsl,imx8mp-pcie", .data = &drvdata[IMX8MP], },
+	{ .compatible = "fsl,imx8q-pcie", .data = &drvdata[IMX8Q], },
 	{ .compatible = "fsl,imx95-pcie", .data = &drvdata[IMX95], },
 	{ .compatible = "fsl,imx8mq-pcie-ep", .data = &drvdata[IMX8MQ_EP], },
 	{ .compatible = "fsl,imx8mm-pcie-ep", .data = &drvdata[IMX8MM_EP], },

-- 
2.34.1