PCI: microchip: Add request_event_irq() callback function

As the PLDA DT binding doc (Documentation/devicetree/bindings/pci/
plda,xpressrich3-axi-common.yaml) shows, the PLDA IP contains an interrupt
controller. Microchip PolarFire add some interrupts based on PLDA interrupt
controller.

The Microchip PolarFire PCIe additional interrupts (defined in
drivers/pci/controller/plda/pcie-microchip-host.c):

  EVENT_PCIE_L2_EXIT
  EVENT_PCIE_HOTRST_EXIT
  EVENT_PCIE_DLUP_EXIT
  EVENT_SEC_TX_RAM_SEC_ERR
  EVENT_SEC_RX_RAM_SEC_ERR
  ...

Both event_cause[] and mc_event_handler() contain additional interrupt
symbol names; these can not be re-used. Add a new plda_event_handler()
function, which implements PLDA interrupt defalt handler, and add a
request_event_irq() callback function for Microchip PolarFire additional
interrupts.

[kwilczynski, bhelgaas: commit log]
Link: https://lore.kernel.org/linux-pci/20240328091835.14797-13-minda.chen@starfivetech.com
Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>

Author: mindachen1987

drivers/pci/controller/plda/pcie-microchip-host.c

@@ -642,6 +642,11 @@ static irqreturn_t mc_event_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t plda_event_handler(int irq, void *dev_id)
+{
+	return IRQ_HANDLED;
+}
+
 static void plda_handle_event(struct irq_desc *desc)
 {
 	struct plda_pcie_rp *port = irq_desc_get_handler_data(desc);
@@ -803,6 +808,17 @@ static int mc_pcie_init_clks(struct device *dev)
 	return 0;
 }
 
+static int mc_request_event_irq(struct plda_pcie_rp *plda, int event_irq,
+				int event)
+{
+	return devm_request_irq(plda->dev, event_irq, mc_event_handler,
+				0, event_cause[event].sym, plda);
+}
+
+static const struct plda_event mc_event = {
+	.request_event_irq = mc_request_event_irq,
+};
+
 static int plda_pcie_init_irq_domains(struct plda_pcie_rp *port)
 {
 	struct device *dev = port->dev;
@@ -904,7 +920,9 @@ static void mc_disable_interrupts(struct mc_pcie *port)
 	writel_relaxed(GENMASK(31, 0), bridge_base_addr + ISTATUS_HOST);
 }
 
-static int plda_init_interrupts(struct platform_device *pdev, struct plda_pcie_rp *port)
+static int plda_init_interrupts(struct platform_device *pdev,
+				struct plda_pcie_rp *port,
+				const struct plda_event *event)
 {
 	struct device *dev = &pdev->dev;
 	int irq;
@@ -928,8 +946,13 @@ static int plda_init_interrupts(struct platform_device *pdev, struct plda_pcie_r
 			return -ENXIO;
 		}
 
-		ret = devm_request_irq(dev, event_irq, mc_event_handler,
-				       0, event_cause[i].sym, port);
+		if (event->request_event_irq)
+			ret = event->request_event_irq(port, event_irq, i);
+		else
+			ret = devm_request_irq(dev, event_irq,
+					       plda_event_handler,
+					       0, NULL, port);
+
 		if (ret) {
 			dev_err(dev, "failed to request IRQ %d\n", event_irq);
 			return ret;
@@ -982,7 +1005,7 @@ static int mc_platform_init(struct pci_config_window *cfg)
 		return ret;
 
 	/* Address translation is up; safe to enable interrupts */
-	ret = plda_init_interrupts(pdev, &port->plda);
+	ret = plda_init_interrupts(pdev, &port->plda, &mc_event);
 	if (ret)
 		return ret;
 

drivers/pci/controller/plda/pcie-plda.h

@@ -127,6 +127,11 @@ struct plda_pcie_rp {
 	int num_events;
 };
 
+struct plda_event {
+	int (*request_event_irq)(struct plda_pcie_rp *pcie,
+				 int event_irq, int event);
+};
+
 void plda_pcie_setup_window(void __iomem *bridge_base_addr, u32 index,
 			    phys_addr_t axi_addr, phys_addr_t pci_addr,
 			    size_t size);