hw/gpio/pl061: Convert to 3-phase reset and assert GPIO lines correctly on reset

The PL061 comes out of reset with all its lines configured as input,
which means they might need to be pulled to 0 or 1 depending on the
'pullups' and 'pulldowns' properties.  Currently we do not assert
these lines on reset; they will only be set whenever the guest first
touches a register that triggers a call to pl061_update().

Convert the device to three-phase reset so we have a place where we
can safely call qemu_set_irq() to set the floating lines to their
correct values.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

2 files changed, 26 insertions, 4 deletions

diff --git a/hw/gpio/pl061.c b/hw/gpio/pl061.c
index 5ba398f..4002ab5 100644
--- a/hw/gpio/pl061.c
+++ b/hw/gpio/pl061.c
@@ -446,13 +446,14 @@ static void pl061_write(void *opaque, hwaddr offset,
     return;
 }
 
-static void pl061_reset(DeviceState *dev)
+static void pl061_enter_reset(Object *obj, ResetType type)
 {
-    PL061State *s = PL061(dev);
+    PL061State *s = PL061(obj);
+
+    trace_pl061_reset(DEVICE(s)->canonical_path);
 
     /* reset values from PL061 TRM, Stellaris LM3S5P31 & LM3S8962 Data Sheet */
     s->data = 0;
-    s->old_out_data = 0;
     s->old_in_data = 0;
     s->dir = 0;
     s->isense = 0;
@@ -474,6 +475,24 @@ static void pl061_reset(DeviceState *dev)
     s->amsel = 0;
 }
 
+static void pl061_hold_reset(Object *obj)
+{
+    PL061State *s = PL061(obj);
+    int i, level;
+    uint8_t floating = pl061_floating(s);
+    uint8_t pullups = pl061_pullups(s);
+
+    for (i = 0; i < N_GPIOS; i++) {
+        if (extract32(floating, i, 1)) {
+            continue;
+        }
+        level = extract32(pullups, i, 1);
+        trace_pl061_set_output(DEVICE(s)->canonical_path, i, level);
+        qemu_set_irq(s->out[i], level);
+    }
+    s->old_out_data = pullups;
+}
+
 static void pl061_set_irq(void * opaque, int irq, int level)
 {
     PL061State *s = (PL061State *)opaque;
@@ -543,11 +562,13 @@ static Property pl061_props[] = {
 static void pl061_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
+    ResettableClass *rc = RESETTABLE_CLASS(klass);
 
     dc->vmsd = &vmstate_pl061;
-    dc->reset = &pl061_reset;
     dc->realize = pl061_realize;
     device_class_set_props(dc, pl061_props);
+    rc->phases.enter = pl061_enter_reset;
+    rc->phases.hold = pl061_hold_reset;
 }
 
 static const TypeInfo pl061_info = {
diff --git a/hw/gpio/trace-events b/hw/gpio/trace-events
index eb5fb47..1dab99c 100644
--- a/hw/gpio/trace-events
+++ b/hw/gpio/trace-events
@@ -20,6 +20,7 @@ pl061_input_change(const char *id, int gpio, int level) "%s input %d changed to
 pl061_update_istate(const char *id, uint32_t istate, uint32_t im, int level) "%s GPIORIS 0x%x GPIOIE 0x%x interrupt level %d"
 pl061_read(const char *id, uint64_t offset, uint64_t r) "%s offset 0x%" PRIx64 " value 0x%" PRIx64
 pl061_write(const char *id, uint64_t offset, uint64_t value) "%s offset 0x%" PRIx64 " value 0x%" PRIx64
+pl061_reset(const char *id) "%s reset"
 
 # sifive_gpio.c
 sifive_gpio_read(uint64_t offset, uint64_t r) "offset 0x%" PRIx64 " value 0x%" PRIx64