[PATCH v2 6/8] pci: mvebu: add support for MSI

[Thomas Petazzoni]

This commit adds support for Message Signaled Interrupts in the
Marvell PCIe host controller. The work is very simple: it simply gets
a reference to the msi_chip associated to the PCIe controller thanks
to the msi-parent DT property, and stores this reference in the
pci_bus structure. This is enough to let the Linux PCI core use the
functions of msi_chip to setup and teardown MSIs.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
 drivers/pci/host/pci-mvebu.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 13a633b..0dc30bd 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -11,6 +11,7 @@
 #include <linux/clk.h>
 #include <linux/module.h>
 #include <linux/mbus.h>
+#include <linux/msi.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
 #include <linux/of_address.h>
@@ -107,6 +108,7 @@ struct mvebu_pcie_port;
 struct mvebu_pcie {
 	struct platform_device *pdev;
 	struct mvebu_pcie_port *ports;
+	struct msi_chip *msi;
 	struct resource io;
 	struct resource realio;
 	struct resource mem;
@@ -690,6 +692,8 @@ static struct pci_bus *mvebu_pcie_scan_bus(int nr, struct pci_sys_data *sys)
 	if (!bus)
 		return NULL;
 
+	bus->msi = pcie->msi;
+
 	pci_scan_child_bus(bus);
 
 	return bus;
@@ -755,6 +759,21 @@ mvebu_pcie_map_registers(struct platform_device *pdev,
 	return devm_request_and_ioremap(&pdev->dev, &regs);
 }
 
+static void __init mvebu_pcie_msi_enable(struct mvebu_pcie *pcie)
+{
+	struct device_node *msi_node;
+
+	msi_node = of_parse_phandle(pcie->pdev->dev.of_node,
+				    "msi-parent", 0);
+	if (!msi_node)
+		return;
+
+	pcie->msi = msi_chip_find_by_of_node(msi_node);
+
+	if (pcie->msi)
+		pcie->msi->dev = &pcie->pdev->dev;
+}
+
 static int __init mvebu_pcie_probe(struct platform_device *pdev)
 {
 	struct mvebu_pcie *pcie;
@@ -879,6 +898,8 @@ static int __init mvebu_pcie_probe(struct platform_device *pdev)
 		i++;
 	}
 
+	mvebu_pcie_msi_enable(pcie);
+
 	mvebu_pcie_enable(pcie);
 
 	return 0;
-- 
1.8.1.2