[PATCH v2 19/20] hw/core: Add FDT support to Remote Port GPIO

[Ruslan Ruslichenko <ruslichenko.r@gmail.com>]

From: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>

Implement the FDTGenericIntc interface for the Remote
Port GPIO device.

This enables the device to be recognized as an interrupt
controller when instantiated via the fdt-generic framework.
It allows other devices defined in the Device Tree to connect
their interrupt lines to this GPIO controller using standard
FDT properties (e.g., 'interrupts' and 'interrupt-parent').

The implementation maps the interrupt specifier from the
Device Tree cells to the corresponding internal GPIO input
line based on the configured cell offset.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Signed-off-by: Takahiro Nakata <takahiro.nakata.wr@renesas.com>
Signed-off-by: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>
---
 hw/core/remote-port-gpio.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/hw/core/remote-port-gpio.c b/hw/core/remote-port-gpio.c
index 43a40315c5..af7f3c6075 100644
--- a/hw/core/remote-port-gpio.c
+++ b/hw/core/remote-port-gpio.c
@@ -20,6 +20,8 @@
 #include "hw/core/irq.h"
 #include "trace.h"
 
+#include "hw/core/fdt_generic_util.h"
+
 #include "hw/core/remote-port.h"
 #include "hw/core/remote-port-proto.h"
 #include "hw/core/remote-port-gpio.h"
@@ -157,14 +159,34 @@ static Property rp_properties[] = {
     DEFINE_PROP_BOOL("posted-updates", RemotePortGPIO, posted_updates, true),
 };
 
+static int rp_fdt_get_irq(FDTGenericIntc *obj, qemu_irq *irqs,
+                          uint32_t *cells, int ncells, int max,
+                          Error **errp)
+{
+    RemotePortGPIO *s = REMOTE_PORT_GPIO(obj);
+
+    if (cells[s->cell_offset_irq_num] >= s->num_gpios) {
+        error_setg(errp, "RP-GPIO was setup for %u interrupts: index %"
+                   PRIu32 " requested", s->num_gpios,
+                   cells[s->cell_offset_irq_num]);
+        return 0;
+    }
+
+    (*irqs) = qdev_get_gpio_in(DEVICE(obj), cells[s->cell_offset_irq_num]);
+    return 1;
+};
+
 static void rp_gpio_class_init(ObjectClass *oc, const void *data)
 {
     RemotePortDeviceClass *rpdc = REMOTE_PORT_DEVICE_CLASS(oc);
     DeviceClass *dc = DEVICE_CLASS(oc);
+    FDTGenericIntcClass *fgic = FDT_GENERIC_INTC_CLASS(oc);
+
     rpdc->ops[RP_CMD_interrupt] = rp_gpio_interrupt;
     dc->legacy_reset = rp_gpio_reset;
     dc->realize = rp_gpio_realize;
     device_class_set_props_n(dc, rp_properties, ARRAY_SIZE(rp_properties));
+    fgic->get_irq = rp_fdt_get_irq;
 }
 
 static const TypeInfo rp_info = {
@@ -175,6 +197,7 @@ static const TypeInfo rp_info = {
     .class_init    = rp_gpio_class_init,
     .interfaces    = (InterfaceInfo[]) {
         { TYPE_REMOTE_PORT_DEVICE },
+        { TYPE_FDT_GENERIC_INTC },
         { },
     },
 };
-- 
2.43.0