[PATCH v4 3/8] hw/misc/pca9552: Use the PCA9552_PIN_COUNT definition

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

The current code models the PCA9552, but there are comments
saying the code could be easily adapted for the rest of the
PCA955x family.
Since we assume we have at most 16 pins (for the PCA9552),
add a definition and check the instance doesn't use more than
this number. This makes the code a bit safer in case other
PCA955x devices are added.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/misc/pca9552.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c
index cfefb8fce8..b97fc2893c 100644
--- a/hw/misc/pca9552.c
+++ b/hw/misc/pca9552.c
@@ -303,6 +303,17 @@ static void pca9552_initfn(Object *obj)
     }
 }
 
+static void pca9552_realize(DeviceState *dev, Error **errp)
+{
+    PCA9552State *s = PCA9552(dev);
+
+    if (s->nr_leds > PCA9552_PIN_COUNT) {
+        error_setg(errp, "%s invalid led count %u (max: %u)",
+                   __func__, s->nr_leds, PCA9552_PIN_COUNT);
+        return;
+    }
+}
+
 static void pca9552_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -311,6 +322,7 @@ static void pca9552_class_init(ObjectClass *klass, void *data)
     k->event = pca9552_event;
     k->recv = pca9552_recv;
     k->send = pca9552_send;
+    dc->realize = pca9552_realize;
     dc->reset = pca9552_reset;
     dc->vmsd = &pca9552_vmstate;
 }
-- 
2.21.3