From: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>

Add TYPE_FDT_GENERIC_INTC class and interface to allow
interrupt controllers to register callback which can
be used to get IRQ's from this controller.

Optionally, interrupt controllers may also provide
auto_parent() callabck which can be used to attach
it to corresponding CPU's or other interrupt parent.

Signed-off-by: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>
---
 hw/core/fdt_generic_util.c         |  7 ++++
 include/hw/core/fdt_generic_util.h | 59 ++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/hw/core/fdt_generic_util.c b/hw/core/fdt_generic_util.c
index c0e974e53a..b22c612e0f 100644
--- a/hw/core/fdt_generic_util.c
+++ b/hw/core/fdt_generic_util.c
@@ -766,6 +766,12 @@ static int fdt_init_qdev(char *node_path, FDTMachineInfo *fdti, char *compat)
     return 0;
 }
 
+static const TypeInfo fdt_generic_intc_info = {
+    .name          = TYPE_FDT_GENERIC_INTC,
+    .parent        = TYPE_INTERFACE,
+    .class_size = sizeof(FDTGenericIntcClass),
+};
+
 static const TypeInfo fdt_generic_mmap_info = {
     .name          = TYPE_FDT_GENERIC_MMAP,
     .parent        = TYPE_INTERFACE,
@@ -774,6 +780,7 @@ static const TypeInfo fdt_generic_mmap_info = {
 
 static void fdt_generic_register_types(void)
 {
+    type_register_static(&fdt_generic_intc_info);
     type_register_static(&fdt_generic_mmap_info);
 }
 type_init(fdt_generic_register_types)
diff --git a/include/hw/core/fdt_generic_util.h b/include/hw/core/fdt_generic_util.h
index 38086ec1e4..c5aaa58dd6 100644
--- a/include/hw/core/fdt_generic_util.h
+++ b/include/hw/core/fdt_generic_util.h
@@ -16,6 +16,65 @@
 
 FDTMachineInfo *fdt_generic_create_machine(void *fdt, qemu_irq *cpu_irq);
 
+#define TYPE_FDT_GENERIC_INTC "fdt-generic-intc"
+
+#define FDT_GENERIC_INTC_CLASS(klass) \
+     OBJECT_CLASS_CHECK(FDTGenericIntcClass, (klass), TYPE_FDT_GENERIC_INTC)
+#define FDT_GENERIC_INTC_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(FDTGenericIntcClass, (obj), TYPE_FDT_GENERIC_INTC)
+#define FDT_GENERIC_INTC(obj) \
+     INTERFACE_CHECK(FDTGenericIntc, (obj), TYPE_FDT_GENERIC_INTC)
+
+typedef struct FDTGenericIntc {
+    /*< private >*/
+    Object parent_obj;
+} FDTGenericIntc;
+
+typedef struct FDTGenericIntcClass {
+    /*< private >*/
+    InterfaceClass parent_class;
+
+    /*< public >*/
+    /**
+     * get irq - Based on the FDT generic interrupt binding for this device
+     * grab the irq(s) for the given interrupt cells description. In some device
+     * tree bindings (E.G. ARM GIC with its PPI) a single interrupt cell-tuple
+     * can describe more than one connection. So populates an array with all
+     * relevant IRQs.
+     *
+     * @obj - interrupt controller to get irqs input for ("interrupt-parent")
+     * @irqs - array to populate with irqs (must be >= @max length
+     * @cells - interrupt cells values. Must be >= ncells length
+     * @ncells - number of cells in @cells
+     * @max - maximum number of irqs to return
+     * @errp - Error condition
+     *
+     * @returns the number of interrupts populated in irqs. Undefined on error
+     * (use errp for error checking). If it is valid for the interrupt
+     * controller binding to specify no (or a disabled) connections it may
+     * return 0 as a non-error.
+     */
+
+    int (*get_irq)(FDTGenericIntc *obj, qemu_irq *irqs, uint32_t *cells,
+                   int ncells, int max, Error **errp);
+
+    /**
+     * auto_parent. An interrupt controller often infers its own interrupt
+     * parent (usually a CPU or CPU cluster. This function allows an interrupt
+     * controller to implement its own auto-connections. Is called if an
+     * interrupt controller itself (detected via "interrupt-controller") has no
+     * "interrupt-parent" node.
+     *
+     * @obj - Interrupt controller top attempt autoconnection
+     * @errp - Error condition
+     *
+     * FIXME: More arguments need to be added for partial descriptions
+     */
+
+    void (*auto_parent)(FDTGenericIntc *obj, Error **errp);
+
+} FDTGenericIntcClass;
+
 #define TYPE_FDT_GENERIC_MMAP "fdt-generic-mmap"
 
 #define FDT_GENERIC_MMAP_CLASS(klass) \
-- 
2.43.0