Merge remote-tracking branch 'remotes/mcayland/tags/qemu-macppc-20200626' into staging

qemu-macppc patches

# gpg: Signature made Fri 26 Jun 2020 10:15:36 BST
# gpg:                using RSA key CC621AB98E82200D915CC9C45BC2C56FAE0F321F
# gpg:                issuer "mark.cave-ayland@ilande.co.uk"
# gpg: Good signature from "Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>" [full]
# Primary key fingerprint: CC62 1AB9 8E82 200D 915C  C9C4 5BC2 C56F AE0F 321F

* remotes/mcayland/tags/qemu-macppc-20200626: (22 commits)
  adb: add ADB bus trace events
  adb: use adb_device prefix for ADB device trace events
  adb: only call autopoll callbacks when autopoll is not blocked
  mac_via: rework ADB state machine to be compatible with both MacOS and Linux
  mac_via: move VIA1 portB write logic into mos6522_q800_via1_write()
  pmu: add adb_autopoll_block() and adb_autopoll_unblock() functions
  cuda: add adb_autopoll_block() and adb_autopoll_unblock() functions
  adb: add autopoll_blocked variable to block autopoll
  adb: use adb_request() only for explicit requests
  adb: add status field for holding information about the last ADB request
  adb: keep track of devices with pending data
  adb: introduce new ADBDeviceHasData method to ADBDeviceClass
  mac_via: convert to use ADBBusState internal autopoll variables
  pmu: convert to use ADBBusState internal autopoll variables
  cuda: convert to use ADBBusState internal autopoll variables
  adb: create autopoll variables directly within ADBBusState
  adb: introduce realize/unrealize and VMStateDescription for ADB bus
  pmu: honour autopoll_rate_ms when rearming the ADB autopoll timer
  pmu: fix duplicate autopoll mask variable
  cuda: convert ADB autopoll timer from ns to ms
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

13 files changed, 620 insertions, 283 deletions

diff --git a/hw/input/adb-kbd.c b/hw/input/adb-kbd.c
index a6d5c9b..3cfb6a7 100644
--- a/hw/input/adb-kbd.c
+++ b/hw/input/adb-kbd.c
@@ -243,7 +243,7 @@ static int adb_kbd_request(ADBDevice *d, uint8_t *obuf,
     olen = 0;
     switch (cmd) {
     case ADB_WRITEREG:
-        trace_adb_kbd_writereg(reg, buf[1]);
+        trace_adb_device_kbd_writereg(reg, buf[1]);
         switch (reg) {
         case 2:
             /* LED status */
@@ -256,24 +256,22 @@ static int adb_kbd_request(ADBDevice *d, uint8_t *obuf,
             case ADB_CMD_CHANGE_ID_AND_ACT:
             case ADB_CMD_CHANGE_ID_AND_ENABLE:
                 d->devaddr = buf[1] & 0xf;
-                trace_adb_kbd_request_change_addr(d->devaddr);
+                trace_adb_device_kbd_request_change_addr(d->devaddr);
                 break;
             default:
-                if (!d->disable_direct_reg3_writes) {
-                    d->devaddr = buf[1] & 0xf;
-
-                    /* we support handlers:
-                     * 1: Apple Standard Keyboard
-                     * 2: Apple Extended Keyboard (LShift = RShift)
-                     * 3: Apple Extended Keyboard (LShift != RShift)
-                     */
-                    if (buf[2] == 1 || buf[2] == 2 || buf[2] == 3) {
-                        d->handler = buf[2];
-                    }
-
-                    trace_adb_kbd_request_change_addr_and_handler(d->devaddr,
-                                                                  d->handler);
+                d->devaddr = buf[1] & 0xf;
+                /*
+                 * we support handlers:
+                 * 1: Apple Standard Keyboard
+                 * 2: Apple Extended Keyboard (LShift = RShift)
+                 * 3: Apple Extended Keyboard (LShift != RShift)
+                 */
+                if (buf[2] == 1 || buf[2] == 2 || buf[2] == 3) {
+                    d->handler = buf[2];
                 }
+
+                trace_adb_device_kbd_request_change_addr_and_handler(
+                    d->devaddr, d->handler);
                 break;
             }
         }
@@ -296,12 +294,19 @@ static int adb_kbd_request(ADBDevice *d, uint8_t *obuf,
             olen = 2;
             break;
         }
-        trace_adb_kbd_readreg(reg, obuf[0], obuf[1]);
+        trace_adb_device_kbd_readreg(reg, obuf[0], obuf[1]);
         break;
     }
     return olen;
 }
 
+static bool adb_kbd_has_data(ADBDevice *d)
+{
+    KBDState *s = ADB_KEYBOARD(d);
+
+    return s->count > 0;
+}
+
 /* This is where keyboard events enter this file */
 static void adb_keyboard_event(DeviceState *dev, QemuConsole *src,
                                InputEvent *evt)
@@ -316,7 +321,7 @@ static void adb_keyboard_event(DeviceState *dev, QemuConsole *src,
     /* FIXME: take handler into account when translating qcode */
     keycode = qcode_to_adb_keycode[qcode];
     if (keycode == NO_KEY) {  /* We don't want to send this to the guest */
-        trace_adb_kbd_no_key();
+        trace_adb_device_kbd_no_key();
         return;
     }
     if (evt->u.key.data->down == false) { /* if key release event */
@@ -384,6 +389,7 @@ static void adb_kbd_class_init(ObjectClass *oc, void *data)
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 
     adc->devreq = adb_kbd_request;
+    adc->devhasdata = adb_kbd_has_data;
     dc->reset = adb_kbd_reset;
     dc->vmsd = &vmstate_adb_kbd;
 }
diff --git a/hw/input/adb-mouse.c b/hw/input/adb-mouse.c
index aeba41b..577a38f 100644
--- a/hw/input/adb-mouse.c
+++ b/hw/input/adb-mouse.c
@@ -121,7 +121,7 @@ static int adb_mouse_request(ADBDevice *d, uint8_t *obuf,
         s->dx = 0;
         s->dy = 0;
         s->dz = 0;
-        trace_adb_mouse_flush();
+        trace_adb_device_mouse_flush();
         return 0;
     }
 
@@ -130,11 +130,21 @@ static int adb_mouse_request(ADBDevice *d, uint8_t *obuf,
     olen = 0;
     switch (cmd) {
     case ADB_WRITEREG:
-        trace_adb_mouse_writereg(reg, buf[1]);
+        trace_adb_device_mouse_writereg(reg, buf[1]);
         switch (reg) {
         case 2:
             break;
         case 3:
+            /*
+             * MacOS 9 has a bug in its ADB driver whereby after configuring
+             * the ADB bus devices it sends another write of invalid length
+             * to reg 3. Make sure we ignore it to prevent an address clash
+             * with the previous device.
+             */
+            if (len != 3) {
+                return 0;
+            }
+
             switch (buf[2]) {
             case ADB_CMD_SELF_TEST:
                 break;
@@ -142,30 +152,28 @@ static int adb_mouse_request(ADBDevice *d, uint8_t *obuf,
             case ADB_CMD_CHANGE_ID_AND_ACT:
             case ADB_CMD_CHANGE_ID_AND_ENABLE:
                 d->devaddr = buf[1] & 0xf;
-                trace_adb_mouse_request_change_addr(d->devaddr);
+                trace_adb_device_mouse_request_change_addr(d->devaddr);
                 break;
             default:
-                if (!d->disable_direct_reg3_writes) {
-                    d->devaddr = buf[1] & 0xf;
-
-                    /* we support handlers:
-                     * 0x01: Classic Apple Mouse Protocol / 100 cpi operations
-                     * 0x02: Classic Apple Mouse Protocol / 200 cpi operations
-                     * we don't support handlers (at least):
-                     * 0x03: Mouse systems A3 trackball
-                     * 0x04: Extended Apple Mouse Protocol
-                     * 0x2f: Microspeed mouse
-                     * 0x42: Macally
-                     * 0x5f: Microspeed mouse
-                     * 0x66: Microspeed mouse
-                     */
-                    if (buf[2] == 1 || buf[2] == 2) {
-                        d->handler = buf[2];
-                    }
-
-                    trace_adb_mouse_request_change_addr_and_handler(
-                        d->devaddr, d->handler);
+                d->devaddr = buf[1] & 0xf;
+                /*
+                 * we support handlers:
+                 * 0x01: Classic Apple Mouse Protocol / 100 cpi operations
+                 * 0x02: Classic Apple Mouse Protocol / 200 cpi operations
+                 * we don't support handlers (at least):
+                 * 0x03: Mouse systems A3 trackball
+                 * 0x04: Extended Apple Mouse Protocol
+                 * 0x2f: Microspeed mouse
+                 * 0x42: Macally
+                 * 0x5f: Microspeed mouse
+                 * 0x66: Microspeed mouse
+                 */
+                if (buf[2] == 1 || buf[2] == 2) {
+                    d->handler = buf[2];
                 }
+
+                trace_adb_device_mouse_request_change_addr_and_handler(
+                    d->devaddr, d->handler);
                 break;
             }
         }
@@ -183,12 +191,20 @@ static int adb_mouse_request(ADBDevice *d, uint8_t *obuf,
             olen = 2;
             break;
         }
-        trace_adb_mouse_readreg(reg, obuf[0], obuf[1]);
+        trace_adb_device_mouse_readreg(reg, obuf[0], obuf[1]);
         break;
     }
     return olen;
 }
 
+static bool adb_mouse_has_data(ADBDevice *d)
+{
+    MouseState *s = ADB_MOUSE(d);
+
+    return !(s->last_buttons_state == s->buttons_state &&
+             s->dx == 0 && s->dy == 0);
+}
+
 static void adb_mouse_reset(DeviceState *dev)
 {
     ADBDevice *d = ADB_DEVICE(dev);
@@ -244,6 +260,7 @@ static void adb_mouse_class_init(ObjectClass *oc, void *data)
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 
     adc->devreq = adb_mouse_request;
+    adc->devhasdata = adb_mouse_has_data;
     dc->reset = adb_mouse_reset;
     dc->vmsd = &vmstate_adb_mouse;
 }
diff --git a/hw/input/adb.c b/hw/input/adb.c
index b1ac4a3..013fcc9 100644
--- a/hw/input/adb.c
+++ b/hw/input/adb.c
@@ -27,41 +27,85 @@
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
 #include "qemu/module.h"
+#include "qemu/timer.h"
 #include "adb-internal.h"
+#include "trace.h"
 
 /* error codes */
 #define ADB_RET_NOTPRESENT (-2)
 
+static const char *adb_commands[] = {
+    "RESET", "FLUSH", "(Reserved 0x2)", "(Reserved 0x3)",
+    "Reserved (0x4)", "(Reserved 0x5)", "(Reserved 0x6)", "(Reserved 0x7)",
+    "LISTEN r0", "LISTEN r1", "LISTEN r2", "LISTEN r3",
+    "TALK r0", "TALK r1", "TALK r2", "TALK r3",
+};
+
 static void adb_device_reset(ADBDevice *d)
 {
     qdev_reset_all(DEVICE(d));
 }
 
-int adb_request(ADBBusState *s, uint8_t *obuf, const uint8_t *buf, int len)
+static int do_adb_request(ADBBusState *s, uint8_t *obuf, const uint8_t *buf,
+                          int len)
 {
     ADBDevice *d;
-    int devaddr, cmd, i;
+    ADBDeviceClass *adc;
+    int devaddr, cmd, olen, i;
 
     cmd = buf[0] & 0xf;
     if (cmd == ADB_BUSRESET) {
-        for(i = 0; i < s->nb_devices; i++) {
+        for (i = 0; i < s->nb_devices; i++) {
             d = s->devices[i];
             adb_device_reset(d);
         }
+        s->status = 0;
         return 0;
     }
+
+    s->pending = 0;
+    for (i = 0; i < s->nb_devices; i++) {
+        d = s->devices[i];
+        adc = ADB_DEVICE_GET_CLASS(d);
+
+        if (adc->devhasdata(d)) {
+            s->pending |= (1 << d->devaddr);
+        }
+    }
+
+    s->status = 0;
     devaddr = buf[0] >> 4;
-    for(i = 0; i < s->nb_devices; i++) {
+    for (i = 0; i < s->nb_devices; i++) {
         d = s->devices[i];
+        adc = ADB_DEVICE_GET_CLASS(d);
+
         if (d->devaddr == devaddr) {
-            ADBDeviceClass *adc = ADB_DEVICE_GET_CLASS(d);
-            return adc->devreq(d, obuf, buf, len);
+            olen = adc->devreq(d, obuf, buf, len);
+            if (!olen) {
+                s->status |= ADB_STATUS_BUSTIMEOUT;
+            }
+            return olen;
         }
     }
+
+    s->status |= ADB_STATUS_BUSTIMEOUT;
     return ADB_RET_NOTPRESENT;
 }
 
-/* XXX: move that to cuda ? */
+int adb_request(ADBBusState *s, uint8_t *obuf, const uint8_t *buf, int len)
+{
+    int ret;
+
+    trace_adb_bus_request(buf[0] >> 4, adb_commands[buf[0] & 0xf], len);
+
+    assert(s->autopoll_blocked);
+
+    ret = do_adb_request(s, obuf, buf, len);
+
+    trace_adb_bus_request_done(buf[0] >> 4, adb_commands[buf[0] & 0xf], ret);
+    return ret;
+}
+
 int adb_poll(ADBBusState *s, uint8_t *obuf, uint16_t poll_mask)
 {
     ADBDevice *d;
@@ -69,18 +113,20 @@ int adb_poll(ADBBusState *s, uint8_t *obuf, uint16_t poll_mask)
     uint8_t buf[1];
 
     olen = 0;
-    for(i = 0; i < s->nb_devices; i++) {
-        if (s->poll_index >= s->nb_devices)
+    for (i = 0; i < s->nb_devices; i++) {
+        if (s->poll_index >= s->nb_devices) {
             s->poll_index = 0;
+        }
         d = s->devices[s->poll_index];
         if ((1 << d->devaddr) & poll_mask) {
             buf[0] = ADB_READREG | (d->devaddr << 4);
-            olen = adb_request(s, obuf + 1, buf, 1);
+            olen = do_adb_request(s, obuf + 1, buf, 1);
             /* if there is data, we poll again the same device */
             if (olen > 0) {
+                s->status |= ADB_STATUS_POLLREPLY;
                 obuf[0] = buf[0];
                 olen++;
-                break;
+                return olen;
             }
         }
         s->poll_index++;
@@ -88,10 +134,145 @@ int adb_poll(ADBBusState *s, uint8_t *obuf, uint16_t poll_mask)
     return olen;
 }
 
+void adb_set_autopoll_enabled(ADBBusState *s, bool enabled)
+{
+    if (s->autopoll_enabled != enabled) {
+        s->autopoll_enabled = enabled;
+        if (s->autopoll_enabled) {
+            timer_mod(s->autopoll_timer,
+                      qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+                      s->autopoll_rate_ms);
+        } else {
+            timer_del(s->autopoll_timer);
+        }
+    }
+}
+
+void adb_set_autopoll_rate_ms(ADBBusState *s, int rate_ms)
+{
+    s->autopoll_rate_ms = rate_ms;
+
+    if (s->autopoll_enabled) {
+        timer_mod(s->autopoll_timer,
+                  qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+                  s->autopoll_rate_ms);
+    }
+}
+
+void adb_set_autopoll_mask(ADBBusState *s, uint16_t mask)
+{
+    if (s->autopoll_mask != mask) {
+        s->autopoll_mask = mask;
+        if (s->autopoll_enabled && s->autopoll_mask) {
+            timer_mod(s->autopoll_timer,
+                      qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+                      s->autopoll_rate_ms);
+        } else {
+            timer_del(s->autopoll_timer);
+        }
+    }
+}
+
+void adb_autopoll_block(ADBBusState *s)
+{
+    s->autopoll_blocked = true;
+    trace_adb_bus_autopoll_block(s->autopoll_blocked);
+
+    if (s->autopoll_enabled) {
+        timer_del(s->autopoll_timer);
+    }
+}
+
+void adb_autopoll_unblock(ADBBusState *s)
+{
+    s->autopoll_blocked = false;
+    trace_adb_bus_autopoll_block(s->autopoll_blocked);
+
+    if (s->autopoll_enabled) {
+        timer_mod(s->autopoll_timer,
+                  qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+                  s->autopoll_rate_ms);
+    }
+}
+
+static void adb_autopoll(void *opaque)
+{
+    ADBBusState *s = opaque;
+
+    if (!s->autopoll_blocked) {
+        trace_adb_bus_autopoll_cb(s->autopoll_mask);
+        s->autopoll_cb(s->autopoll_cb_opaque);
+        trace_adb_bus_autopoll_cb_done(s->autopoll_mask);
+    }
+
+    timer_mod(s->autopoll_timer,
+              qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+              s->autopoll_rate_ms);
+}
+
+void adb_register_autopoll_callback(ADBBusState *s, void (*cb)(void *opaque),
+                                    void *opaque)
+{
+    s->autopoll_cb = cb;
+    s->autopoll_cb_opaque = opaque;
+}
+
+static const VMStateDescription vmstate_adb_bus = {
+    .name = "adb_bus",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .fields = (VMStateField[]) {
+        VMSTATE_TIMER_PTR(autopoll_timer, ADBBusState),
+        VMSTATE_BOOL(autopoll_enabled, ADBBusState),
+        VMSTATE_UINT8(autopoll_rate_ms, ADBBusState),
+        VMSTATE_UINT16(autopoll_mask, ADBBusState),
+        VMSTATE_BOOL(autopoll_blocked, ADBBusState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void adb_bus_reset(BusState *qbus)
+{
+    ADBBusState *adb_bus = ADB_BUS(qbus);
+
+    adb_bus->autopoll_enabled = false;
+    adb_bus->autopoll_mask = 0xffff;
+    adb_bus->autopoll_rate_ms = 20;
+}
+
+static void adb_bus_realize(BusState *qbus, Error **errp)
+{
+    ADBBusState *adb_bus = ADB_BUS(qbus);
+
+    adb_bus->autopoll_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, adb_autopoll,
+                                           adb_bus);
+
+    vmstate_register(NULL, -1, &vmstate_adb_bus, adb_bus);
+}
+
+static void adb_bus_unrealize(BusState *qbus)
+{
+    ADBBusState *adb_bus = ADB_BUS(qbus);
+
+    timer_del(adb_bus->autopoll_timer);
+
+    vmstate_unregister(NULL, &vmstate_adb_bus, adb_bus);
+}
+
+static void adb_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->realize = adb_bus_realize;
+    k->unrealize = adb_bus_unrealize;
+    k->reset = adb_bus_reset;
+}
+
 static const TypeInfo adb_bus_type_info = {
     .name = TYPE_ADB_BUS,
     .parent = TYPE_BUS,
     .instance_size = sizeof(ADBBusState),
+    .class_init = adb_bus_class_init,
 };
 
 const VMStateDescription vmstate_adb_device = {
@@ -117,18 +298,11 @@ static void adb_device_realizefn(DeviceState *dev, Error **errp)
     bus->devices[bus->nb_devices++] = d;
 }
 
-static Property adb_device_properties[] = {
-    DEFINE_PROP_BOOL("disable-direct-reg3-writes", ADBDevice,
-                     disable_direct_reg3_writes, false),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void adb_device_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
 
     dc->realize = adb_device_realizefn;
-    device_class_set_props(dc, adb_device_properties);
     dc->bus_type = TYPE_ADB_BUS;
 }
 
diff --git a/hw/input/trace-events b/hw/input/trace-events
index a2888fd..1dd8ad6 100644
--- a/hw/input/trace-events
+++ b/hw/input/trace-events
@@ -1,18 +1,25 @@
 # See docs/devel/tracing.txt for syntax documentation.
 
 # adb-kbd.c
-adb_kbd_no_key(void) "Ignoring NO_KEY"
-adb_kbd_writereg(int reg, uint8_t val) "reg %d val 0x%2.2x"
-adb_kbd_readreg(int reg, uint8_t val0, uint8_t val1) "reg %d obuf[0] 0x%2.2x obuf[1] 0x%2.2x"
-adb_kbd_request_change_addr(int devaddr) "change addr to 0x%x"
-adb_kbd_request_change_addr_and_handler(int devaddr, int handler) "change addr and handler to 0x%x, 0x%x"
+adb_device_kbd_no_key(void) "Ignoring NO_KEY"
+adb_device_kbd_writereg(int reg, uint8_t val) "reg %d val 0x%2.2x"
+adb_device_kbd_readreg(int reg, uint8_t val0, uint8_t val1) "reg %d obuf[0] 0x%2.2x obuf[1] 0x%2.2x"
+adb_device_kbd_request_change_addr(int devaddr) "change addr to 0x%x"
+adb_device_kbd_request_change_addr_and_handler(int devaddr, int handler) "change addr and handler to 0x%x, 0x%x"
 
 # adb-mouse.c
-adb_mouse_flush(void) "flush"
-adb_mouse_writereg(int reg, uint8_t val) "reg %d val 0x%2.2x"
-adb_mouse_readreg(int reg, uint8_t val0, uint8_t val1) "reg %d obuf[0] 0x%2.2x obuf[1] 0x%2.2x"
-adb_mouse_request_change_addr(int devaddr) "change addr to 0x%x"
-adb_mouse_request_change_addr_and_handler(int devaddr, int handler) "change addr and handler to 0x%x, 0x%x"
+adb_device_mouse_flush(void) "flush"
+adb_device_mouse_writereg(int reg, uint8_t val) "reg %d val 0x%2.2x"
+adb_device_mouse_readreg(int reg, uint8_t val0, uint8_t val1) "reg %d obuf[0] 0x%2.2x obuf[1] 0x%2.2x"
+adb_device_mouse_request_change_addr(int devaddr) "change addr to 0x%x"
+adb_device_mouse_request_change_addr_and_handler(int devaddr, int handler) "change addr and handler to 0x%x, 0x%x"
+
+# adb.c
+adb_bus_request(uint8_t addr, const char *cmd, int size) "device 0x%x %s cmdsize=%d"
+adb_bus_request_done(uint8_t addr, const char *cmd, int size) "device 0x%x %s replysize=%d"
+adb_bus_autopoll_block(bool blocked) "blocked: %d"
+adb_bus_autopoll_cb(uint16_t mask) "executing autopoll_cb with autopoll mask 0x%x"
+adb_bus_autopoll_cb_done(uint16_t mask) "done executing autopoll_cb with autopoll mask 0x%x"
 
 # pckbd.c
 pckbd_kbd_read_data(uint32_t val) "0x%02x"
diff --git a/hw/misc/mac_via.c b/hw/misc/mac_via.c
index 9cd313c..d76d7b2 100644
--- a/hw/misc/mac_via.c
+++ b/hw/misc/mac_via.c
@@ -599,179 +599,310 @@ static void via1_rtc_update(MacVIAState *m)
     m->cmd = REG_EMPTY;
 }
 
-static int adb_via_poll(MacVIAState *s, int state, uint8_t *data)
+static void adb_via_poll(void *opaque)
 {
-    if (state != ADB_STATE_IDLE) {
-        return 0;
-    }
+    MacVIAState *m = opaque;
+    MOS6522Q800VIA1State *v1s = MOS6522_Q800_VIA1(&m->mos6522_via1);
+    MOS6522State *s = MOS6522(v1s);
+    ADBBusState *adb_bus = &m->adb_bus;
+    uint8_t obuf[9];
+    uint8_t *data = &s->sr;
+    int olen;
+    uint16_t pending;
 
-    if (s->adb_data_in_size < s->adb_data_in_index) {
-        return 0;
-    }
+    /*
+     * Setting vADBInt below indicates that an autopoll reply has been
+     * received, however we must block autopoll until the point where
+     * the entire reply has been read back to the host
+     */
+    adb_autopoll_block(adb_bus);
+
+    m->adb_data_in_index = 0;
+    m->adb_data_out_index = 0;
+    olen = adb_poll(adb_bus, obuf, adb_bus->autopoll_mask);
+
+    if (olen > 0) {
+        /* Autopoll response */
+        *data = obuf[0];
+        olen--;
+        memcpy(m->adb_data_in, &obuf[1], olen);
+        m->adb_data_in_size = olen;
+
+        s->b &= ~VIA1B_vADBInt;
+        qemu_irq_raise(m->adb_data_ready);
+    } else if (olen < 0) {
+        /* Bus timeout (device does not exist) */
+        *data = 0xff;
+        s->b |= VIA1B_vADBInt;
+        adb_autopoll_unblock(adb_bus);
+    } else {
+        pending = adb_bus->pending & ~(1 << (m->adb_autopoll_cmd >> 4));
+
+        if (pending) {
+            /*
+             * Bus timeout (device exists but another device has data). Block
+             * autopoll so the OS can read out the first EVEN and first ODD
+             * byte to determine bus timeout and SRQ status
+             */
+            *data = m->adb_autopoll_cmd;
+            s->b &= ~VIA1B_vADBInt;
 
-    if (s->adb_data_out_index != 0) {
-        return 0;
-    }
+            obuf[0] = 0xff;
+            obuf[1] = 0xff;
+            olen = 2;
 
-    s->adb_data_in_index = 0;
-    s->adb_data_out_index = 0;
-    s->adb_data_in_size = adb_poll(&s->adb_bus, s->adb_data_in, 0xffff);
+            memcpy(m->adb_data_in, obuf, olen);
+            m->adb_data_in_size = olen;
 
-    if (s->adb_data_in_size) {
-        *data = s->adb_data_in[s->adb_data_in_index++];
-        qemu_irq_raise(s->adb_data_ready);
+            qemu_irq_raise(m->adb_data_ready);
+        } else {
+            /* Bus timeout (device exists but no other device has data) */
+            *data = 0;
+            s->b |= VIA1B_vADBInt;
+            adb_autopoll_unblock(adb_bus);
+        }
     }
 
-    return s->adb_data_in_size;
+    trace_via1_adb_poll(*data, (s->b & VIA1B_vADBInt) ? "+" : "-",
+                        adb_bus->status, m->adb_data_in_index, olen);
 }
 
-static int adb_via_send(MacVIAState *s, int state, uint8_t data)
+static int adb_via_send_len(uint8_t data)
 {
-    switch (state) {
-    case ADB_STATE_NEW:
-        s->adb_data_out_index = 0;
-        break;
-    case ADB_STATE_EVEN:
-        if ((s->adb_data_out_index & 1) == 0) {
-            return 0;
-        }
-        break;
-    case ADB_STATE_ODD:
-        if (s->adb_data_out_index & 1) {
-            return 0;
+    /* Determine the send length from the given ADB command */
+    uint8_t cmd = data & 0xc;
+    uint8_t reg = data & 0x3;
+
+    switch (cmd) {
+    case 0x8:
+        /* Listen command */
+        switch (reg) {
+        case 2:
+            /* Register 2 is only used for the keyboard */
+            return 3;
+        case 3:
+            /*
+             * Fortunately our devices only implement writes
+             * to register 3 which is fixed at 2 bytes
+             */
+            return 3;
+        default:
+            qemu_log_mask(LOG_UNIMP, "ADB unknown length for register %d\n",
+                          reg);
+            return 1;
         }
-        break;
-    case ADB_STATE_IDLE:
-        return 0;
+    default:
+        /* Talk, BusReset */
+        return 1;
     }
-
-    assert(s->adb_data_out_index < sizeof(s->adb_data_out) - 1);
-
-    s->adb_data_out[s->adb_data_out_index++] = data;
-    qemu_irq_raise(s->adb_data_ready);
-    return 1;
 }
 
-static int adb_via_receive(MacVIAState *s, int state, uint8_t *data)
+static void adb_via_send(MacVIAState *s, int state, uint8_t data)
 {
+    MOS6522Q800VIA1State *v1s = MOS6522_Q800_VIA1(&s->mos6522_via1);
+    MOS6522State *ms = MOS6522(v1s);
+    ADBBusState *adb_bus = &s->adb_bus;
+    uint16_t autopoll_mask;
+
     switch (state) {
     case ADB_STATE_NEW:
-        return 0;
-
-    case ADB_STATE_EVEN:
-        if (s->adb_data_in_size <= 0) {
-            qemu_irq_raise(s->adb_data_ready);
-            return 0;
-        }
-
-        if (s->adb_data_in_index >= s->adb_data_in_size) {
-            *data = 0;
-            qemu_irq_raise(s->adb_data_ready);
-            return 1;
-        }
-
-        if ((s->adb_data_in_index & 1) == 0) {
-            return 0;
+        /*
+         * Command byte: vADBInt tells host autopoll data already present
+         * in VIA shift register and ADB transceiver
+         */
+        adb_autopoll_block(adb_bus);
+
+        if (adb_bus->status & ADB_STATUS_POLLREPLY) {
+            /* Tell the host the existing data is from autopoll */
+            ms->b &= ~VIA1B_vADBInt;
+        } else {
+            ms->b |= VIA1B_vADBInt;
+            s->adb_data_out_index = 0;
+            s->adb_data_out[s->adb_data_out_index++] = data;
         }
 
+        trace_via1_adb_send(" NEW", data, (ms->b & VIA1B_vADBInt) ? "+" : "-");
+        qemu_irq_raise(s->adb_data_ready);
         break;
 
+    case ADB_STATE_EVEN:
     case ADB_STATE_ODD:
-        if (s->adb_data_in_size <= 0) {
-            qemu_irq_raise(s->adb_data_ready);
-            return 0;
-        }
-
-        if (s->adb_data_in_index >= s->adb_data_in_size) {
-            *data = 0;
-            qemu_irq_raise(s->adb_data_ready);
-            return 1;
-        }
-
-        if (s->adb_data_in_index & 1) {
-            return 0;
-        }
+        ms->b |= VIA1B_vADBInt;
+        s->adb_data_out[s->adb_data_out_index++] = data;
 
+        trace_via1_adb_send(state == ADB_STATE_EVEN ? "EVEN" : " ODD",
+                            data, (ms->b & VIA1B_vADBInt) ? "+" : "-");
+        qemu_irq_raise(s->adb_data_ready);
         break;
 
     case ADB_STATE_IDLE:
-        if (s->adb_data_out_index == 0) {
-            return 0;
-        }
+        return;
+    }
 
-        s->adb_data_in_size = adb_request(&s->adb_bus, s->adb_data_in,
+    /* If the command is complete, execute it */
+    if (s->adb_data_out_index == adb_via_send_len(s->adb_data_out[0])) {
+        s->adb_data_in_size = adb_request(adb_bus, s->adb_data_in,
                                           s->adb_data_out,
                                           s->adb_data_out_index);
-        s->adb_data_out_index = 0;
         s->adb_data_in_index = 0;
-        if (s->adb_data_in_size < 0) {
-            *data = 0xff;
-            qemu_irq_raise(s->adb_data_ready);
-            return -1;
-        }
 
-        if (s->adb_data_in_size == 0) {
-            return 0;
+        if (adb_bus->status & ADB_STATUS_BUSTIMEOUT) {
+            /*
+             * Bus timeout (but allow first EVEN and ODD byte to indicate
+             * timeout via vADBInt and SRQ status)
+             */
+            s->adb_data_in[0] = 0xff;
+            s->adb_data_in[1] = 0xff;
+            s->adb_data_in_size = 2;
         }
 
-        break;
-    }
-
-    assert(s->adb_data_in_index < sizeof(s->adb_data_in) - 1);
+        /*
+         * If last command is TALK, store it for use by autopoll and adjust
+         * the autopoll mask accordingly
+         */
+        if ((s->adb_data_out[0] & 0xc) == 0xc) {
+            s->adb_autopoll_cmd = s->adb_data_out[0];
 
-    *data = s->adb_data_in[s->adb_data_in_index++];
-    qemu_irq_raise(s->adb_data_ready);
-    if (*data == 0xff || *data == 0) {
-        return 0;
+            autopoll_mask = 1 << (s->adb_autopoll_cmd >> 4);
+            adb_set_autopoll_mask(adb_bus, autopoll_mask);
+        }
     }
-    return 1;
 }
 
-static void via1_adb_update(MacVIAState *m)
+static void adb_via_receive(MacVIAState *s, int state, uint8_t *data)
 {
-    MOS6522Q800VIA1State *v1s = MOS6522_Q800_VIA1(&m->mos6522_via1);
-    MOS6522State *s = MOS6522(v1s);
-    int state;
-    int ret;
+    MOS6522Q800VIA1State *v1s = MOS6522_Q800_VIA1(&s->mos6522_via1);
+    MOS6522State *ms = MOS6522(v1s);
+    ADBBusState *adb_bus = &s->adb_bus;
+    uint16_t pending;
 
-    state = (s->b & VIA1B_vADB_StateMask) >> VIA1B_vADB_StateShift;
+    switch (state) {
+    case ADB_STATE_NEW:
+        ms->b |= VIA1B_vADBInt;
+        return;
 
-    if (s->acr & VIA1ACR_vShiftOut) {
-        /* output mode */
-        ret = adb_via_send(m, state, s->sr);
-        if (ret > 0) {
-            s->b &= ~VIA1B_vADBInt;
+    case ADB_STATE_IDLE:
+        /*
+         * Since adb_request() will have already consumed the data from the
+         * device, we must detect this extra state change and re-inject the
+         * reponse as either a "fake" autopoll reply or bus timeout
+         * accordingly
+         */
+        if (s->adb_data_in_index == 0) {
+            if (adb_bus->status & ADB_STATUS_BUSTIMEOUT) {
+                *data = 0xff;
+                ms->b |= VIA1B_vADBInt;
+                qemu_irq_raise(s->adb_data_ready);
+            } else if (s->adb_data_in_size > 0) {
+                adb_bus->status = ADB_STATUS_POLLREPLY;
+                *data = s->adb_autopoll_cmd;
+                ms->b &= ~VIA1B_vADBInt;
+                qemu_irq_raise(s->adb_data_ready);
+            }
         } else {
-            s->b |= VIA1B_vADBInt;
+            ms->b |= VIA1B_vADBInt;
+            adb_autopoll_unblock(adb_bus);
         }
-    } else {
-        /* input mode */
-        ret = adb_via_receive(m, state, &s->sr);
-        if (ret > 0 && s->sr != 0xff) {
-            s->b &= ~VIA1B_vADBInt;
-        } else {
-            s->b |= VIA1B_vADBInt;
+
+        trace_via1_adb_receive("IDLE", *data,
+                        (ms->b & VIA1B_vADBInt) ? "+" : "-", adb_bus->status,
+                        s->adb_data_in_index, s->adb_data_in_size);
+
+        break;
+
+    case ADB_STATE_EVEN:
+    case ADB_STATE_ODD:
+        switch (s->adb_data_in_index) {
+        case 0:
+            /* First EVEN byte: vADBInt indicates bus timeout */
+            trace_via1_adb_receive(state == ADB_STATE_EVEN ? "EVEN" : " ODD",
+                                   *data, (ms->b & VIA1B_vADBInt) ? "+" : "-",
+                                   adb_bus->status, s->adb_data_in_index,
+                                   s->adb_data_in_size);
+
+            *data = s->adb_data_in[s->adb_data_in_index++];
+            if (adb_bus->status & ADB_STATUS_BUSTIMEOUT) {
+                ms->b &= ~VIA1B_vADBInt;
+            } else {
+                ms->b |= VIA1B_vADBInt;
+            }
+            break;
+
+        case 1:
+            /* First ODD byte: vADBInt indicates SRQ */
+            trace_via1_adb_receive(state == ADB_STATE_EVEN ? "EVEN" : " ODD",
+                                   *data, (ms->b & VIA1B_vADBInt) ? "+" : "-",
+                                   adb_bus->status, s->adb_data_in_index,
+                                   s->adb_data_in_size);
+
+            *data = s->adb_data_in[s->adb_data_in_index++];
+            pending = adb_bus->pending & ~(1 << (s->adb_autopoll_cmd >> 4));
+            if (pending) {
+                ms->b &= ~VIA1B_vADBInt;
+            } else {
+                ms->b |= VIA1B_vADBInt;
+            }
+            break;
+
+        default:
+            /*
+             * Otherwise vADBInt indicates end of data. Note that Linux
+             * specifically checks for the sequence 0x0 0xff to confirm the
+             * end of the poll reply, so provide these extra bytes below to
+             * keep it happy
+             */
+            trace_via1_adb_receive(state == ADB_STATE_EVEN ? "EVEN" : " ODD",
+                                   *data, (ms->b & VIA1B_vADBInt) ? "+" : "-",
+                                   adb_bus->status, s->adb_data_in_index,
+                                   s->adb_data_in_size);
+
+            if (s->adb_data_in_index < s->adb_data_in_size) {
+                /* Next data byte */
+                *data = s->adb_data_in[s->adb_data_in_index++];
+                ms->b |= VIA1B_vADBInt;
+            } else if (s->adb_data_in_index == s->adb_data_in_size) {
+                if (adb_bus->status & ADB_STATUS_BUSTIMEOUT) {
+                    /* Bus timeout (no more data) */
+                    *data = 0xff;
+                } else {
+                    /* Return 0x0 after reply */
+                    *data = 0;
+                }
+                s->adb_data_in_index++;
+                ms->b &= ~VIA1B_vADBInt;
+            } else {
+                /* Bus timeout (no more data) */
+                *data = 0xff;
+                ms->b &= ~VIA1B_vADBInt;
+                adb_bus->status = 0;
+                adb_autopoll_unblock(adb_bus);
+            }
+            break;
         }
+
+        qemu_irq_raise(s->adb_data_ready);
+        break;
     }
 }
 
-static void via_adb_poll(void *opaque)
+static void via1_adb_update(MacVIAState *m)
 {
-    MacVIAState *m = opaque;
     MOS6522Q800VIA1State *v1s = MOS6522_Q800_VIA1(&m->mos6522_via1);
     MOS6522State *s = MOS6522(v1s);
-    int state;
+    int oldstate, state;
 
-    if (s->b & VIA1B_vADBInt) {
-        state = (s->b & VIA1B_vADB_StateMask) >> VIA1B_vADB_StateShift;
-        if (adb_via_poll(m, state, &s->sr)) {
-            s->b &= ~VIA1B_vADBInt;
+    oldstate = (v1s->last_b & VIA1B_vADB_StateMask) >> VIA1B_vADB_StateShift;
+    state = (s->b & VIA1B_vADB_StateMask) >> VIA1B_vADB_StateShift;
+
+    if (state != oldstate) {
+        if (s->acr & VIA1ACR_vShiftOut) {
+            /* output mode */
+            adb_via_send(m, state, s->sr);
+        } else {
+            /* input mode */
+            adb_via_receive(m, state, &s->sr);
         }
     }
-
-    timer_mod(m->adb_poll_timer,
-              qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
-              (NANOSECONDS_PER_SECOND / VIA_ADB_POLL_FREQ));
 }
 
 static uint64_t mos6522_q800_via1_read(void *opaque, hwaddr addr, unsigned size)
@@ -802,11 +933,21 @@ static void mos6522_q800_via1_write(void *opaque, hwaddr addr, uint64_t val,
                                     unsigned size)
 {
     MOS6522Q800VIA1State *v1s = MOS6522_Q800_VIA1(opaque);
+    MacVIAState *m = container_of(v1s, MacVIAState, mos6522_via1);
     MOS6522State *ms = MOS6522(v1s);
 
     addr = (addr >> 9) & 0xf;
     mos6522_write(ms, addr, val, size);
 
+    switch (addr) {
+    case VIA_REG_B:
+        via1_rtc_update(m);
+        via1_adb_update(m);
+
+        v1s->last_b = ms->b;
+        break;
+    }
+
     via1_one_second_update(v1s);
     via1_VBL_update(v1s);
 }
@@ -854,10 +995,9 @@ static void mac_via_reset(DeviceState *dev)
 {
     MacVIAState *m = MAC_VIA(dev);
     MOS6522Q800VIA1State *v1s = &m->mos6522_via1;
+    ADBBusState *adb_bus = &m->adb_bus;
 
-    timer_mod(m->adb_poll_timer,
-              qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
-              (NANOSECONDS_PER_SECOND / VIA_ADB_POLL_FREQ));
+    adb_set_autopoll_enabled(adb_bus, true);
 
     timer_del(v1s->VBL_timer);
     v1s->next_VBL = 0;
@@ -872,6 +1012,7 @@ static void mac_via_realize(DeviceState *dev, Error **errp)
 {
     MacVIAState *m = MAC_VIA(dev);
     MOS6522State *ms;
+    ADBBusState *adb_bus = &m->adb_bus;
     struct tm tm;
     int ret;
 
@@ -907,7 +1048,7 @@ static void mac_via_realize(DeviceState *dev, Error **errp)
     qemu_get_timedate(&tm, 0);
     m->tick_offset = (uint32_t)mktimegm(&tm) + RTC_OFFSET;
 
-    m->adb_poll_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, via_adb_poll, m);
+    adb_register_autopoll_callback(adb_bus, adb_via_poll, m);
     m->adb_data_ready = qdev_get_gpio_in_named(dev, "via1-irq",
                                                VIA1_IRQ_ADB_READY_BIT);
 
@@ -980,8 +1121,8 @@ static int mac_via_post_load(void *opaque, int version_id)
 
 static const VMStateDescription vmstate_mac_via = {
     .name = "mac-via",
-    .version_id = 1,
-    .minimum_version_id = 1,
+    .version_id = 2,
+    .minimum_version_id = 2,
     .post_load = mac_via_post_load,
     .fields = (VMStateField[]) {
         /* VIAs */
@@ -1005,12 +1146,12 @@ static const VMStateDescription vmstate_mac_via = {
         VMSTATE_INT32(wprotect, MacVIAState),
         VMSTATE_INT32(alt, MacVIAState),
         /* ADB */
-        VMSTATE_TIMER_PTR(adb_poll_timer, MacVIAState),
         VMSTATE_INT32(adb_data_in_size, MacVIAState),
         VMSTATE_INT32(adb_data_in_index, MacVIAState),
         VMSTATE_INT32(adb_data_out_index, MacVIAState),
         VMSTATE_BUFFER(adb_data_in, MacVIAState),
         VMSTATE_BUFFER(adb_data_out, MacVIAState),
+        VMSTATE_UINT8(adb_autopoll_cmd, MacVIAState),
         VMSTATE_END_OF_LIST()
     }
 };
@@ -1039,18 +1180,6 @@ static TypeInfo mac_via_info = {
 };
 
 /* VIA 1 */
-static void mos6522_q800_via1_portB_write(MOS6522State *s)
-{
-    MOS6522Q800VIA1State *v1s = container_of(s, MOS6522Q800VIA1State,
-                                             parent_obj);
-    MacVIAState *m = container_of(v1s, MacVIAState, mos6522_via1);
-
-    via1_rtc_update(m);
-    via1_adb_update(m);
-
-    v1s->last_b = s->b;
-}
-
 static void mos6522_q800_via1_reset(DeviceState *dev)
 {
     MOS6522State *ms = MOS6522(dev);
@@ -1073,10 +1202,8 @@ static void mos6522_q800_via1_init(Object *obj)
 static void mos6522_q800_via1_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
-    MOS6522DeviceClass *mdc = MOS6522_DEVICE_CLASS(oc);
 
     dc->reset = mos6522_q800_via1_reset;
-    mdc->portB_write = mos6522_q800_via1_portB_write;
 }
 
 static const TypeInfo mos6522_q800_via1_type_info = {
diff --git a/hw/misc/macio/cuda.c b/hw/misc/macio/cuda.c
index 47aa3b0..5bbc777 100644
--- a/hw/misc/macio/cuda.c
+++ b/hw/misc/macio/cuda.c
@@ -116,6 +116,7 @@ static void cuda_update(CUDAState *s)
 {
     MOS6522CUDAState *mcs = &s->mos6522_cuda;
     MOS6522State *ms = MOS6522(mcs);
+    ADBBusState *adb_bus = &s->adb_bus;
     int packet_received, len;
 
     packet_received = 0;
@@ -126,6 +127,9 @@ static void cuda_update(CUDAState *s)
             /* data output */
             if ((ms->b & (TACK | TIP)) != (s->last_b & (TACK | TIP))) {
                 if (s->data_out_index < sizeof(s->data_out)) {
+                    if (s->data_out_index == 0) {
+                        adb_autopoll_block(adb_bus);
+                    }
                     trace_cuda_data_send(ms->sr);
                     s->data_out[s->data_out_index++] = ms->sr;
                     cuda_delay_set_sr_int(s);
@@ -140,6 +144,7 @@ static void cuda_update(CUDAState *s)
                     /* indicate end of transfer */
                     if (s->data_in_index >= s->data_in_size) {
                         ms->b = (ms->b | TREQ);
+                        adb_autopoll_unblock(adb_bus);
                     }
                     cuda_delay_set_sr_int(s);
                 }
@@ -201,17 +206,16 @@ static void cuda_send_packet_to_host(CUDAState *s,
 static void cuda_adb_poll(void *opaque)
 {
     CUDAState *s = opaque;
+    ADBBusState *adb_bus = &s->adb_bus;
     uint8_t obuf[ADB_MAX_OUT_LEN + 2];
     int olen;
 
-    olen = adb_poll(&s->adb_bus, obuf + 2, s->adb_poll_mask);
+    olen = adb_poll(adb_bus, obuf + 2, adb_bus->autopoll_mask);
     if (olen > 0) {
         obuf[0] = ADB_PACKET;
         obuf[1] = 0x40; /* polled data */
         cuda_send_packet_to_host(s, obuf, olen + 2);
     }
-    timer_mod(s->adb_poll_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
-              (NANOSECONDS_PER_SECOND / (1000 / s->autopoll_rate_ms)));
 }
 
 /* description of commands */
@@ -227,23 +231,16 @@ static bool cuda_cmd_autopoll(CUDAState *s,
                               const uint8_t *in_data, int in_len,
                               uint8_t *out_data, int *out_len)
 {
-    int autopoll;
+    ADBBusState *adb_bus = &s->adb_bus;
+    bool autopoll;
 
     if (in_len != 1) {
         return false;
     }
 
-    autopoll = (in_data[0] != 0);
-    if (autopoll != s->autopoll) {
-        s->autopoll = autopoll;
-        if (autopoll) {
-            timer_mod(s->adb_poll_timer,
-                      qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
-                      (NANOSECONDS_PER_SECOND / (1000 / s->autopoll_rate_ms)));
-        } else {
-            timer_del(s->adb_poll_timer);
-        }
-    }
+    autopoll = (in_data[0] != 0) ? true : false;
+
+    adb_set_autopoll_enabled(adb_bus, autopoll);
     return true;
 }
 
@@ -251,6 +248,8 @@ static bool cuda_cmd_set_autorate(CUDAState *s,
                                   const uint8_t *in_data, int in_len,
                                   uint8_t *out_data, int *out_len)
 {
+    ADBBusState *adb_bus = &s->adb_bus;
+
     if (in_len != 1) {
         return false;
     }
@@ -261,12 +260,7 @@ static bool cuda_cmd_set_autorate(CUDAState *s,
         return false;
     }
 
-    s->autopoll_rate_ms = in_data[0];
-    if (s->autopoll) {
-        timer_mod(s->adb_poll_timer,
-                  qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
-                  (NANOSECONDS_PER_SECOND / (1000 / s->autopoll_rate_ms)));
-    }
+    adb_set_autopoll_rate_ms(adb_bus, in_data[0]);
     return true;
 }
 
@@ -274,11 +268,16 @@ static bool cuda_cmd_set_device_list(CUDAState *s,
                                      const uint8_t *in_data, int in_len,
                                      uint8_t *out_data, int *out_len)
 {
+    ADBBusState *adb_bus = &s->adb_bus;
+    uint16_t mask;
+
     if (in_len != 2) {
         return false;
     }
 
-    s->adb_poll_mask = (((uint16_t)in_data[0]) << 8) | in_data[1];
+    mask = (((uint16_t)in_data[0]) << 8) | in_data[1];
+
+    adb_set_autopoll_mask(adb_bus, mask);
     return true;
 }
 
@@ -489,8 +488,8 @@ static const MemoryRegionOps mos6522_cuda_ops = {
 
 static const VMStateDescription vmstate_cuda = {
     .name = "cuda",
-    .version_id = 5,
-    .minimum_version_id = 5,
+    .version_id = 6,
+    .minimum_version_id = 6,
     .fields = (VMStateField[]) {
         VMSTATE_STRUCT(mos6522_cuda.parent_obj, CUDAState, 0, vmstate_mos6522,
                        MOS6522State),
@@ -499,13 +498,9 @@ static const VMStateDescription vmstate_cuda = {
         VMSTATE_INT32(data_in_size, CUDAState),
         VMSTATE_INT32(data_in_index, CUDAState),
         VMSTATE_INT32(data_out_index, CUDAState),
-        VMSTATE_UINT8(autopoll, CUDAState),
-        VMSTATE_UINT8(autopoll_rate_ms, CUDAState),
-        VMSTATE_UINT16(adb_poll_mask, CUDAState),
         VMSTATE_BUFFER(data_in, CUDAState),
         VMSTATE_BUFFER(data_out, CUDAState),
         VMSTATE_UINT32(tick_offset, CUDAState),
-        VMSTATE_TIMER_PTR(adb_poll_timer, CUDAState),
         VMSTATE_TIMER_PTR(sr_delay_timer, CUDAState),
         VMSTATE_END_OF_LIST()
     }
@@ -514,11 +509,13 @@ static const VMStateDescription vmstate_cuda = {
 static void cuda_reset(DeviceState *dev)
 {
     CUDAState *s = CUDA(dev);
+    ADBBusState *adb_bus = &s->adb_bus;
 
     s->data_in_size = 0;
     s->data_in_index = 0;
     s->data_out_index = 0;
-    s->autopoll = 0;
+
+    adb_set_autopoll_enabled(adb_bus, false);
 }
 
 static void cuda_realize(DeviceState *dev, Error **errp)
@@ -526,6 +523,7 @@ static void cuda_realize(DeviceState *dev, Error **errp)
     CUDAState *s = CUDA(dev);
     Error *err = NULL;
     SysBusDevice *sbd;
+    ADBBusState *adb_bus = &s->adb_bus;
     struct tm tm;
 
     sysbus_realize(SYS_BUS_DEVICE(&s->mos6522_cuda), &err);
@@ -544,9 +542,7 @@ static void cuda_realize(DeviceState *dev, Error **errp)
     s->sr_delay_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, cuda_set_sr_int, s);
     s->sr_delay_ns = 20 * SCALE_US;
 
-    s->adb_poll_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, cuda_adb_poll, s);
-    s->adb_poll_mask = 0xffff;
-    s->autopoll_rate_ms = 20;
+    adb_register_autopoll_callback(adb_bus, cuda_adb_poll, s);
 }
 
 static void cuda_init(Object *obj)
diff --git a/hw/misc/macio/pmu.c b/hw/misc/macio/pmu.c
index 41b626c..598d8e7 100644
--- a/hw/misc/macio/pmu.c
+++ b/hw/misc/macio/pmu.c
@@ -92,10 +92,11 @@ static void pmu_update_extirq(PMUState *s)
 static void pmu_adb_poll(void *opaque)
 {
     PMUState *s = opaque;
+    ADBBusState *adb_bus = &s->adb_bus;
     int olen;
 
     if (!(s->intbits & PMU_INT_ADB)) {
-        olen = adb_poll(&s->adb_bus, s->adb_reply, s->adb_poll_mask);
+        olen = adb_poll(adb_bus, s->adb_reply, adb_bus->autopoll_mask);
         trace_pmu_adb_poll(olen);
 
         if (olen > 0) {
@@ -104,9 +105,6 @@ static void pmu_adb_poll(void *opaque)
             pmu_update_extirq(s);
         }
     }
-
-    timer_mod(s->adb_poll_timer,
-              qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 30);
 }
 
 static void pmu_one_sec_timer(void *opaque)
@@ -173,18 +171,15 @@ static void pmu_cmd_set_int_mask(PMUState *s,
 
 static void pmu_cmd_set_adb_autopoll(PMUState *s, uint16_t mask)
 {
-    trace_pmu_cmd_set_adb_autopoll(mask);
+    ADBBusState *adb_bus = &s->adb_bus;
 
-    if (s->autopoll_mask == mask) {
-        return;
-    }
+    trace_pmu_cmd_set_adb_autopoll(mask);
 
-    s->autopoll_mask = mask;
     if (mask) {
-        timer_mod(s->adb_poll_timer,
-                  qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 30);
+        adb_set_autopoll_mask(adb_bus, mask);
+        adb_set_autopoll_enabled(adb_bus, true);
     } else {
-        timer_del(s->adb_poll_timer);
+        adb_set_autopoll_enabled(adb_bus, false);
     }
 }
 
@@ -267,6 +262,8 @@ static void pmu_cmd_adb_poll_off(PMUState *s,
                                  const uint8_t *in_data, uint8_t in_len,
                                  uint8_t *out_data, uint8_t *out_len)
 {
+    ADBBusState *adb_bus = &s->adb_bus;
+
     if (in_len != 0) {
         qemu_log_mask(LOG_GUEST_ERROR,
                       "PMU: ADB POLL OFF command, invalid len: %d want: 0\n",
@@ -274,9 +271,8 @@ static void pmu_cmd_adb_poll_off(PMUState *s,
         return;
     }
 
-    if (s->has_adb && s->autopoll_mask) {
-        timer_del(s->adb_poll_timer);
-        s->autopoll_mask = false;
+    if (s->has_adb) {
+        adb_set_autopoll_enabled(adb_bus, false);
     }
 }
 
@@ -521,6 +517,7 @@ static void pmu_update(PMUState *s)
 {
     MOS6522PMUState *mps = &s->mos6522_pmu;
     MOS6522State *ms = MOS6522(mps);
+    ADBBusState *adb_bus = &s->adb_bus;
 
     /* Only react to changes in reg B */
     if (ms->b == s->last_b) {
@@ -582,6 +579,7 @@ static void pmu_update(PMUState *s)
         s->cmd_rsp_pos = 0;
         s->cmd_state = pmu_state_cmd;
 
+        adb_autopoll_block(adb_bus);
         trace_pmu_debug_protocol_cmd(s->cmd, s->cmdlen, s->rsplen);
         break;
 
@@ -640,6 +638,7 @@ static void pmu_update(PMUState *s)
     if (s->cmd_state == pmu_state_rsp && s->rsplen == s->cmd_rsp_pos) {
         trace_pmu_debug_protocol_cmd_resp_complete(ms->ier);
 
+        adb_autopoll_unblock(adb_bus);
         s->cmd_state = pmu_state_idle;
     }
 }
@@ -684,12 +683,10 @@ static bool pmu_adb_state_needed(void *opaque)
 
 static const VMStateDescription vmstate_pmu_adb = {
     .name = "pmu/adb",
-    .version_id = 0,
-    .minimum_version_id = 0,
+    .version_id = 1,
+    .minimum_version_id = 1,
     .needed = pmu_adb_state_needed,
     .fields = (VMStateField[]) {
-        VMSTATE_UINT16(adb_poll_mask, PMUState),
-        VMSTATE_TIMER_PTR(adb_poll_timer, PMUState),
         VMSTATE_UINT8(adb_reply_size, PMUState),
         VMSTATE_BUFFER(adb_reply, PMUState),
         VMSTATE_END_OF_LIST()
@@ -698,8 +695,8 @@ static const VMStateDescription vmstate_pmu_adb = {
 
 static const VMStateDescription vmstate_pmu = {
     .name = "pmu",
-    .version_id = 0,
-    .minimum_version_id = 0,
+    .version_id = 1,
+    .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_STRUCT(mos6522_pmu.parent_obj, PMUState, 0, vmstate_mos6522,
                        MOS6522State),
@@ -714,8 +711,6 @@ static const VMStateDescription vmstate_pmu = {
         VMSTATE_BUFFER(cmd_rsp, PMUState),
         VMSTATE_UINT8(intbits, PMUState),
         VMSTATE_UINT8(intmask, PMUState),
-        VMSTATE_UINT8(autopoll_rate_ms, PMUState),
-        VMSTATE_UINT8(autopoll_mask, PMUState),
         VMSTATE_UINT32(tick_offset, PMUState),
         VMSTATE_TIMER_PTR(one_sec_timer, PMUState),
         VMSTATE_INT64(one_sec_target, PMUState),
@@ -735,7 +730,6 @@ static void pmu_reset(DeviceState *dev)
     s->intbits = 0;
 
     s->cmd_state = pmu_state_idle;
-    s->autopoll_mask = 0;
 }
 
 static void pmu_realize(DeviceState *dev, Error **errp)
@@ -743,6 +737,7 @@ static void pmu_realize(DeviceState *dev, Error **errp)
     PMUState *s = VIA_PMU(dev);
     Error *err = NULL;
     SysBusDevice *sbd;
+    ADBBusState *adb_bus = &s->adb_bus;
     struct tm tm;
 
     sysbus_realize(SYS_BUS_DEVICE(&s->mos6522_pmu), &err);
@@ -764,9 +759,7 @@ static void pmu_realize(DeviceState *dev, Error **errp)
     if (s->has_adb) {
         qbus_create_inplace(&s->adb_bus, sizeof(s->adb_bus), TYPE_ADB_BUS,
                             dev, "adb.0");
-        s->adb_poll_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, pmu_adb_poll, s);
-        s->adb_poll_mask = 0xffff;
-        s->autopoll_rate_ms = 20;
+        adb_register_autopoll_callback(adb_bus, pmu_adb_poll, s);
     }
 }
 
diff --git a/hw/misc/trace-events b/hw/misc/trace-events
index 5561746..68a6d9f 100644
--- a/hw/misc/trace-events
+++ b/hw/misc/trace-events
@@ -202,6 +202,9 @@ via1_rtc_cmd_pram_read(int addr, int value) "addr=%u value=0x%02x"
 via1_rtc_cmd_pram_write(int addr, int value) "addr=%u value=0x%02x"
 via1_rtc_cmd_pram_sect_read(int sector, int offset, int addr, int value) "sector=%u offset=%u addr=%d value=0x%02x"
 via1_rtc_cmd_pram_sect_write(int sector, int offset, int addr, int value) "sector=%u offset=%u addr=%d value=0x%02x"
+via1_adb_send(const char *state, uint8_t data, const char *vadbint) "state %s data=0x%02x vADBInt=%s"
+via1_adb_receive(const char *state, uint8_t data, const char *vadbint, int status, int index, int size) "state %s data=0x%02x vADBInt=%s status=0x%x index=%d size=%d"
+via1_adb_poll(uint8_t data, const char *vadbint, int status, int index, int size) "data=0x%02x vADBInt=%s status=0x%x index=%d size=%d"
 
 # grlib_ahb_apb_pnp.c
 grlib_ahb_pnp_read(uint64_t addr, uint32_t value) "AHB PnP read addr:0x%03"PRIx64" data:0x%08x"
diff --git a/hw/ppc/mac_newworld.c b/hw/ppc/mac_newworld.c
index 5f3a028..828c599 100644
--- a/hw/ppc/mac_newworld.c
+++ b/hw/ppc/mac_newworld.c
@@ -404,11 +404,9 @@ static void ppc_core99_init(MachineState *machine)
 
         adb_bus = qdev_get_child_bus(dev, "adb.0");
         dev = qdev_new(TYPE_ADB_KEYBOARD);
-        qdev_prop_set_bit(dev, "disable-direct-reg3-writes", true);
         qdev_realize_and_unref(dev, adb_bus, &error_fatal);
 
         dev = qdev_new(TYPE_ADB_MOUSE);
-        qdev_prop_set_bit(dev, "disable-direct-reg3-writes", true);
         qdev_realize_and_unref(dev, adb_bus, &error_fatal);
     }
 
diff --git a/include/hw/input/adb.h b/include/hw/input/adb.h
index b7b32e2..bb75a7b 100644
--- a/include/hw/input/adb.h
+++ b/include/hw/input/adb.h
@@ -39,6 +39,8 @@ typedef struct ADBDevice ADBDevice;
 typedef int ADBDeviceRequest(ADBDevice *d, uint8_t *buf_out,
                               const uint8_t *buf, int len);
 
+typedef bool ADBDeviceHasData(ADBDevice *d);
+
 #define TYPE_ADB_DEVICE "adb-device"
 #define ADB_DEVICE(obj) OBJECT_CHECK(ADBDevice, (obj), TYPE_ADB_DEVICE)
 
@@ -49,7 +51,6 @@ struct ADBDevice {
 
     int devaddr;
     int handler;
-    bool disable_direct_reg3_writes;
 };
 
 #define ADB_DEVICE_CLASS(cls) \
@@ -63,25 +64,48 @@ typedef struct ADBDeviceClass {
     /*< public >*/
 
     ADBDeviceRequest *devreq;
+    ADBDeviceHasData *devhasdata;
 } ADBDeviceClass;
 
 #define TYPE_ADB_BUS "apple-desktop-bus"
 #define ADB_BUS(obj) OBJECT_CHECK(ADBBusState, (obj), TYPE_ADB_BUS)
 
+#define ADB_STATUS_BUSTIMEOUT  0x1
+#define ADB_STATUS_POLLREPLY   0x2
+
 struct ADBBusState {
     /*< private >*/
     BusState parent_obj;
     /*< public >*/
 
     ADBDevice *devices[MAX_ADB_DEVICES];
+    uint16_t pending;
     int nb_devices;
     int poll_index;
+    uint8_t status;
+
+    QEMUTimer *autopoll_timer;
+    bool autopoll_enabled;
+    bool autopoll_blocked;
+    uint8_t autopoll_rate_ms;
+    uint16_t autopoll_mask;
+    void (*autopoll_cb)(void *opaque);
+    void *autopoll_cb_opaque;
 };
 
 int adb_request(ADBBusState *s, uint8_t *buf_out,
                 const uint8_t *buf, int len);
 int adb_poll(ADBBusState *s, uint8_t *buf_out, uint16_t poll_mask);
 
+void adb_autopoll_block(ADBBusState *s);
+void adb_autopoll_unblock(ADBBusState *s);
+
+void adb_set_autopoll_enabled(ADBBusState *s, bool enabled);
+void adb_set_autopoll_rate_ms(ADBBusState *s, int rate_ms);
+void adb_set_autopoll_mask(ADBBusState *s, uint16_t mask);
+void adb_register_autopoll_callback(ADBBusState *s, void (*cb)(void *opaque),
+                                    void *opaque);
+
 #define TYPE_ADB_KEYBOARD "adb-keyboard"
 #define TYPE_ADB_MOUSE "adb-mouse"
 
diff --git a/include/hw/misc/mac_via.h b/include/hw/misc/mac_via.h
index e74f85b..0be05d6 100644
--- a/include/hw/misc/mac_via.h
+++ b/include/hw/misc/mac_via.h
@@ -106,13 +106,13 @@ typedef struct MacVIAState {
 
     /* ADB */
     ADBBusState adb_bus;
-    QEMUTimer *adb_poll_timer;
     qemu_irq adb_data_ready;
     int adb_data_in_size;
     int adb_data_in_index;
     int adb_data_out_index;
     uint8_t adb_data_in[128];
     uint8_t adb_data_out[16];
+    uint8_t adb_autopoll_cmd;
 } MacVIAState;
 
 #endif
diff --git a/include/hw/misc/macio/cuda.h b/include/hw/misc/macio/cuda.h
index 5768075..a8cf0be 100644
--- a/include/hw/misc/macio/cuda.h
+++ b/include/hw/misc/macio/cuda.h
@@ -95,12 +95,8 @@ typedef struct CUDAState {
     int data_out_index;
 
     qemu_irq irq;
-    uint16_t adb_poll_mask;
-    uint8_t autopoll_rate_ms;
-    uint8_t autopoll;
     uint8_t data_in[128];
     uint8_t data_out[16];
-    QEMUTimer *adb_poll_timer;
 } CUDAState;
 
 #endif /* CUDA_H */
diff --git a/include/hw/misc/macio/pmu.h b/include/hw/misc/macio/pmu.h
index 7ef83de..72f7561 100644
--- a/include/hw/misc/macio/pmu.h
+++ b/include/hw/misc/macio/pmu.h
@@ -218,10 +218,6 @@ typedef struct PMUState {
     /* ADB */
     bool has_adb;
     ADBBusState adb_bus;
-    uint16_t adb_poll_mask;
-    uint8_t autopoll_rate_ms;
-    uint8_t autopoll_mask;
-    QEMUTimer *adb_poll_timer;
     uint8_t adb_reply_size;
     uint8_t adb_reply[ADB_MAX_OUT_LEN];