hw/net/xilinx_ethlite: Map MDIO registers (as unimplemented)

Rather than handling the MDIO registers as RAM, map them
as unimplemented I/O within the device MR.

The memory flat view becomes:

  (qemu) info mtree -f
  FlatView #0
   Root memory region: system
    0000000081000000-00000000810007e3 (prio 0, i/o): xlnx.xps-ethernetlite
    00000000810007e4-00000000810007f3 (prio 0, i/o): ethlite.mdio
    00000000810007f4-0000000081001fff (prio 0, i/o): xlnx.xps-ethernetlite @00000000000007f4

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Message-Id: <20241112181044.92193-7-philmd@linaro.org>

diff --git a/hw/net/xilinx_ethlite.c b/hw/net/xilinx_ethlite.c
index 88ab331acce9bc60203965ac961d0589883ce181..442467abeb8e4fa2e335fe2650c314626332d668 100644 (file)
--- a/hw/net/xilinx_ethlite.c
+++ b/hw/net/xilinx_ethlite.c
@@ -28,15 +28,18 @@
 #include "qemu/osdep.h"
 #include "qemu/module.h"
 #include "qom/object.h"
+#include "qapi/error.h"
 #include "exec/tswap.h"
 #include "hw/sysbus.h"
 #include "hw/irq.h"
 #include "hw/qdev-properties.h"
+#include "hw/misc/unimp.h"
 #include "net/net.h"
 #include "trace.h"
 
 #define R_TX_BUF0     0
 #define BUFSZ_MAX      0x07e4
+#define A_MDIO_BASE    0x07e4
 #define R_TX_LEN0     (0x07f4 / 4)
 #define R_TX_GIE0     (0x07f8 / 4)
 #define R_TX_CTRL0    (0x07fc / 4)
@@ -72,6 +75,7 @@ struct XlnxXpsEthLite
     uint32_t c_rx_pingpong;
     unsigned int port_index; /* dual port RAM index */
 
+    UnimplementedDeviceState mdio;
     uint32_t regs[R_MAX];
 };
 
@@ -232,6 +236,14 @@ static void xilinx_ethlite_realize(DeviceState *dev, Error **errp)
 {
     XlnxXpsEthLite *s = XILINX_ETHLITE(dev);
 
+    object_initialize_child(OBJECT(dev), "ethlite.mdio", &s->mdio,
+                            TYPE_UNIMPLEMENTED_DEVICE);
+    qdev_prop_set_string(DEVICE(&s->mdio), "name", "ethlite.mdio");
+    qdev_prop_set_uint64(DEVICE(&s->mdio), "size", 4 * 4);
+    sysbus_realize(SYS_BUS_DEVICE(&s->mdio), &error_fatal);
+    memory_region_add_subregion(&s->mmio, A_MDIO_BASE,
+                           sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->mdio), 0));
+
     qemu_macaddr_default_if_unset(&s->conf.macaddr);
     s->nic = qemu_new_nic(&net_xilinx_ethlite_info, &s->conf,
                           object_get_typename(OBJECT(dev)), dev->id,