[PATCH V2 2/2] PCI: generic: Add msi_parent DT binding

[<suravee.suthikulpanit@amd.com>]

From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

This patch introduces a new DT binding, msi-parent, which can
be used to specify MSI-parent phandle for a particular PCI
generic host controller.

Also, it implements and registers set_msi_parent callback.

Cc: Bjorn Helgass <bhelgaas@google.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
 Documentation/devicetree/bindings/pci/host-generic-pci.txt |  3 +++
 drivers/pci/host/pci-host-generic.c                        | 13 +++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.txt b/Documentation/devicetree/bindings/pci/host-generic-pci.txt
index cf3e205..6996af7 100644
--- a/Documentation/devicetree/bindings/pci/host-generic-pci.txt
+++ b/Documentation/devicetree/bindings/pci/host-generic-pci.txt
@@ -36,6 +36,8 @@ Properties of the host controller node:
 - reg            : The Configuration Space base address and size, as accessed
                    from the parent bus.
 
+- msi-parent     : Specify the phandle of the corresponded MSI controller
+                   for this PCI host controller.
 
 Properties of the /chosen node:
 
@@ -77,6 +79,7 @@ pci {
     device_type = "pci";
     #address-cells = <3>;
     #size-cells = <2>;
+    msi-parent = <&msictrl0>;
     bus-range = <0x0 0x1>;
 
     // CPU_PHYSICAL(2)  SIZE(2)
diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
index 1895907..c4fbcda 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -42,6 +42,7 @@ struct gen_pci {
 	struct pci_host_bridge			host;
 	struct gen_pci_cfg_windows		cfg;
 	struct list_head			resources;
+	struct msi_chip				*mchip;
 };
 
 static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
@@ -122,9 +123,19 @@ static int gen_pci_config_write(struct pci_bus *bus, unsigned int devfn,
 	return PCIBIOS_SUCCESSFUL;
 }
 
+static int gen_pci_set_msi_parent(struct pci_bus *bus)
+{
+	struct gen_pci *pci = bus_to_gen_pci(bus);
+
+	bus->msi = pci->mchip;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
 static struct pci_ops gen_pci_ops = {
 	.read	= gen_pci_config_read,
 	.write	= gen_pci_config_write,
+	.set_msi_parent = gen_pci_set_msi_parent,
 };
 
 static const struct of_device_id gen_pci_of_match[] = {
@@ -303,6 +314,8 @@ static int gen_pci_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	pci->mchip = of_pci_find_msi_chip_by_node(of_parse_phandle(np,
+						  "msi-parent", 0));
 	pci_common_init_dev(dev, &hw);
 	return 0;
 }
-- 
1.9.3