[PATCH v2 2/2] PCI: xilinx-cpm: Add support for Versal Net CPM5NC Root Port controller

[Thippeswamy Havalige <thippeswamy.havalige@amd.com>]

The Versal Net ACAP (Adaptive Compute Acceleration Platform) devices
incorporate the Coherency and PCIe Gen5 Module, specifically the
Next-Generation Compact Module (CPM5NC).

The integrated CPM5NC block, along with the built-in bridge, can function
as a PCIe Root Port & supports the PCIe Gen5 protocol with data transfer
rates of up to 32 GT/s, capable of supporting up to a x16 lane-width
configuration.

Bridge errors are managed using a specific interrupt line designed for
CPM5N. Intx interrupt support is not available.

Currently in this patch Bridge errors support is not added.

Signed-off-by: Thippeswamy Havalige <thippeswamy.havalige@amd.com>
---
Changes in v2:
- Update commit message.
---
 drivers/pci/controller/pcie-xilinx-cpm.c | 85 ++++++++++++++----------
 1 file changed, 51 insertions(+), 34 deletions(-)

diff --git a/drivers/pci/controller/pcie-xilinx-cpm.c b/drivers/pci/controller/pcie-xilinx-cpm.c
index 81e8bfae53d0..c26ba662efd7 100644
--- a/drivers/pci/controller/pcie-xilinx-cpm.c
+++ b/drivers/pci/controller/pcie-xilinx-cpm.c
@@ -84,6 +84,7 @@ enum xilinx_cpm_version {
 	CPM,
 	CPM5,
 	CPM5_HOST1,
+	CPM5NC_HOST,
 };
 
 /**
@@ -483,31 +484,33 @@ static void xilinx_cpm_pcie_init_port(struct xilinx_cpm_pcie *port)
 	else
 		dev_info(port->dev, "PCIe Link is DOWN\n");
 
-	/* Disable all interrupts */
-	pcie_write(port, ~XILINX_CPM_PCIE_IDR_ALL_MASK,
-		   XILINX_CPM_PCIE_REG_IMR);
-
-	/* Clear pending interrupts */
-	pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_IDR) &
-		   XILINX_CPM_PCIE_IMR_ALL_MASK,
-		   XILINX_CPM_PCIE_REG_IDR);
-
-	/*
-	 * XILINX_CPM_PCIE_MISC_IR_ENABLE register is mapped to
-	 * CPM SLCR block.
-	 */
-	writel(variant->ir_misc_value,
-	       port->cpm_base + XILINX_CPM_PCIE_MISC_IR_ENABLE);
+	if (variant->version != CPM5NC_HOST) {
+		/* Disable all interrupts */
+		pcie_write(port, ~XILINX_CPM_PCIE_IDR_ALL_MASK,
+			   XILINX_CPM_PCIE_REG_IMR);
+
+		/* Clear pending interrupts */
+		pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_IDR) &
+			   XILINX_CPM_PCIE_IMR_ALL_MASK,
+			   XILINX_CPM_PCIE_REG_IDR);
+
+		/*
+		 * XILINX_CPM_PCIE_MISC_IR_ENABLE register is mapped to
+		 * CPM SLCR block.
+		 */
+		writel(variant->ir_misc_value,
+		       port->cpm_base + XILINX_CPM_PCIE_MISC_IR_ENABLE);
+
+		if (variant->ir_enable) {
+			writel(XILINX_CPM_PCIE_IR_LOCAL,
+			       port->cpm_base + variant->ir_enable);
+		}
 
-	if (variant->ir_enable) {
-		writel(XILINX_CPM_PCIE_IR_LOCAL,
-		       port->cpm_base + variant->ir_enable);
+		/* Set Bridge enable bit */
+		pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_RPSC) |
+			   XILINX_CPM_PCIE_REG_RPSC_BEN,
+			   XILINX_CPM_PCIE_REG_RPSC);
 	}
-
-	/* Set Bridge enable bit */
-	pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_RPSC) |
-		   XILINX_CPM_PCIE_REG_RPSC_BEN,
-		   XILINX_CPM_PCIE_REG_RPSC);
 }
 
 /**
@@ -578,16 +581,18 @@ static int xilinx_cpm_pcie_probe(struct platform_device *pdev)
 
 	port->dev = dev;
 
-	err = xilinx_cpm_pcie_init_irq_domain(port);
-	if (err)
-		return err;
+	port->variant = of_device_get_match_data(dev);
+
+	if (port->variant->version != CPM5NC_HOST) {
+		err = xilinx_cpm_pcie_init_irq_domain(port);
+		if (err)
+			return err;
+	}
 
 	bus = resource_list_first_type(&bridge->windows, IORESOURCE_BUS);
 	if (!bus)
 		return -ENODEV;
 
-	port->variant = of_device_get_match_data(dev);
-
 	err = xilinx_cpm_pcie_parse_dt(port, bus->res);
 	if (err) {
 		dev_err(dev, "Parsing DT failed\n");
@@ -596,10 +601,12 @@ static int xilinx_cpm_pcie_probe(struct platform_device *pdev)
 
 	xilinx_cpm_pcie_init_port(port);
 
-	err = xilinx_cpm_setup_irq(port);
-	if (err) {
-		dev_err(dev, "Failed to set up interrupts\n");
-		goto err_setup_irq;
+	if (port->variant->version != CPM5NC_HOST) {
+		err = xilinx_cpm_setup_irq(port);
+		if (err) {
+			dev_err(dev, "Failed to set up interrupts\n");
+			goto err_setup_irq;
+		}
 	}
 
 	bridge->sysdata = port->cfg;
@@ -612,11 +619,13 @@ static int xilinx_cpm_pcie_probe(struct platform_device *pdev)
 	return 0;
 
 err_host_bridge:
-	xilinx_cpm_free_interrupts(port);
+	if (port->variant->version != CPM5NC_HOST)
+		xilinx_cpm_free_interrupts(port);
 err_setup_irq:
 	pci_ecam_free(port->cfg);
 err_parse_dt:
-	xilinx_cpm_free_irq_domains(port);
+	if (port->variant->version != CPM5NC_HOST)
+		xilinx_cpm_free_irq_domains(port);
 	return err;
 }
 
@@ -639,6 +648,10 @@ static const struct xilinx_cpm_variant cpm5_host1 = {
 	.ir_enable = XILINX_CPM_PCIE1_IR_ENABLE,
 };
 
+static const struct xilinx_cpm_variant cpm5n_host = {
+	.version = CPM5NC_HOST,
+};
+
 static const struct of_device_id xilinx_cpm_pcie_of_match[] = {
 	{
 		.compatible = "xlnx,versal-cpm-host-1.00",
@@ -652,6 +665,10 @@ static const struct of_device_id xilinx_cpm_pcie_of_match[] = {
 		.compatible = "xlnx,versal-cpm5-host1",
 		.data = &cpm5_host1,
 	},
+	{
+		.compatible = "xlnx,versal-cpm5nc-host",
+		.data = &cpm5n_host,
+	},
 	{}
 };
 
-- 
2.43.0