Re: [Qemu-devel] [Qemu-ppc] [PATCH] adb: change handler only when recognized

[BALATON Zoltan <balaton@eik.bme.hu>]

On Tue, 9 Aug 2016, Benjamin Herrenschmidt wrote:
> On Sat, 2016-03-12 at 14:38 +0100, Hervé Poussineau wrote:
>> ADB devices must take new handler into account only when they
>> recognize it.
>> This lets operating systems probe for valid/invalid handles, to know
>> device capabilities.
>>
>> Add a FIXME in keyboard handler, which should use a different
>> translation
>> table depending of the selected handler.
>
> Ah interesting ! I was just debugging why my new via-pmu model in Qemu
> makes the ADB mouse emulation not work, while I tracked it down to
> problems in that area and started re-inventing ... your patch :-)
>
> The other issue is we shouldn't let the device change address unless
> it's one of the "special" handler IDs. MacOS 9 with a PMU tries to
> send an oddball 3-bytes write to register 3 during boot to the mouse
> (probably some Trackpad related magic) with "2" in the address field,
> if we accept the address change, things go very wrong.

I don't know much about this but I've read here 
<http://mcosre.sourceforge.net/docs/apple_io.html> that there are three 
different kind of chips: CUDA, PMU99 and PMU. Confusingly both PMU-s are 
called via-pmu by Apple. I think we want PMU99 which is found on desktop 
machines and not PMU found in Powerbooks (unless we want to emulate that) 
because PMU99 has less features and more similar to CUDA. But it has some 
differences such as a different interrupt mentioned in this page and maybe 
others. However, desktop machines have no ADB so I'm not sure why we have 
one still in QEMU. If USB is working then we don't need ADB with PMU99 and 
that could resolve all the problems with it. We can keep it to old world 
beige G3 with CUDA where it works. I think only some Powerbooks have PMU 
and ADB but we are not targeting that. Here's an (untested) patch for 
switching to using USB keyboard and mouse instead of ADB unless USB is 
disabled. (The device tree should be changed accordingly in OpenBIOS.) Not 
sure if this is helpful.

--
Regards, 
BALATON Zoltan

diff --git a/hw/ppc/mac_newworld.c b/hw/ppc/mac_newworld.c
index 7d25106..bf8ad9b 100644
--- a/hw/ppc/mac_newworld.c
+++ b/hw/ppc/mac_newworld.c
@@ -418,24 +418,21 @@ static void ppc_core99_init(MachineState *machine)
                                                          "ide[1]"));
      macio_ide_init_drives(macio_ide, &hd[MAX_IDE_DEVS]);

-    dev = DEVICE(object_resolve_path_component(OBJECT(macio), "cuda"));
-    adb_bus = qdev_get_child_bus(dev, "adb.0");
-    dev = qdev_create(adb_bus, TYPE_ADB_KEYBOARD);
-    qdev_init_nofail(dev);
-    dev = qdev_create(adb_bus, TYPE_ADB_MOUSE);
-    qdev_init_nofail(dev);
-
      if (machine->usb) {
          pci_create_simple(pci_bus, -1, "pci-ohci");

-        /* U3 needs to use USB for input because Linux doesn't support via-cuda
-        on PPC64 */
-        if (machine_arch == ARCH_MAC99_U3) {
-            USBBus *usb_bus = usb_bus_find(-1);
+        /* New world machines have USB instead of ADB */
+        USBBus *usb_bus = usb_bus_find(-1);

-            usb_create_simple(usb_bus, "usb-kbd");
-            usb_create_simple(usb_bus, "usb-mouse");
-        }
+        usb_create_simple(usb_bus, "usb-kbd");
+        usb_create_simple(usb_bus, "usb-mouse");
+    } else {
+        dev = DEVICE(object_resolve_path_component(OBJECT(macio), "cuda"));
+        adb_bus = qdev_get_child_bus(dev, "adb.0");
+        dev = qdev_create(adb_bus, TYPE_ADB_KEYBOARD);
+        qdev_init_nofail(dev);
+        dev = qdev_create(adb_bus, TYPE_ADB_MOUSE);
+        qdev_init_nofail(dev);
      }

      pci_vga_init(pci_bus);