ppc/pnv: scan ISA bus to populate device tree

This is an empty shell that we will use to include nodes in the device
tree for ISA devices. We expect RTC, UART and IPMI BT devices.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/pnv.c

@@ -303,6 +303,29 @@ static void powernv_populate_chip(PnvChip *chip, void *fdt)
     g_free(typename);
 }
 
+typedef struct ForeachPopulateArgs {
+    void *fdt;
+    int offset;
+} ForeachPopulateArgs;
+
+static int powernv_populate_isa_device(DeviceState *dev, void *opaque)
+{
+    return 0;
+}
+
+static void powernv_populate_isa(ISABus *bus, void *fdt, int lpc_offset)
+{
+    ForeachPopulateArgs args = {
+        .fdt = fdt,
+        .offset = lpc_offset,
+    };
+
+    /* ISA devices are not necessarily parented to the ISA bus so we
+     * can not use object_child_foreach() */
+    qbus_walk_children(BUS(bus), powernv_populate_isa_device,
+                       NULL, NULL, NULL, &args);
+}
+
 static void *powernv_create_fdt(MachineState *machine)
 {
     const char plat_compat[] = "qemu,powernv\0ibm,powernv";
@@ -311,6 +334,7 @@ static void *powernv_create_fdt(MachineState *machine)
     char *buf;
     int off;
     int i;
+    int lpc_offset;
 
     fdt = g_malloc0(FDT_MAX_SIZE);
     _FDT((fdt_create_empty_tree(fdt, FDT_MAX_SIZE)));
@@ -350,6 +374,10 @@ static void *powernv_create_fdt(MachineState *machine)
     for (i = 0; i < pnv->num_chips; i++) {
         powernv_populate_chip(pnv->chips[i], fdt);
     }
+
+    /* Populate ISA devices on chip 0 */
+    lpc_offset = pnv_chip_lpc_offset(pnv->chips[0], fdt);
+    powernv_populate_isa(pnv->isa_bus, fdt, lpc_offset);
     return fdt;
 }