hw/i2c: Enable an id for the pca954x devices

This allows the devices to be more readily found and specified.
Without setting the name field, they can only be found by device type
name, which doesn't let you specify the second of the same device type
behind a bus.

Tested: Verified that by default the device was findable with the name
'pca954x[77]', for an instance attached at that address.

Signed-off-by: Patrick Venture <venture@google.com>
Reviewed-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Corey Minyard <cminyard@mvista.com>
Message-Id: <20230322172136.48010-1-venture@google.com>
[PMD: Fix typo in property name]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

hw/i2c/i2c_mux_pca954x.c

@@ -20,6 +20,7 @@
 #include "hw/i2c/i2c_mux_pca954x.h"
 #include "hw/i2c/smbus_slave.h"
 #include "hw/qdev-core.h"
+#include "hw/qdev-properties.h"
 #include "hw/sysbus.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
@@ -43,6 +44,8 @@ typedef struct Pca954xState {
 
     bool enabled[PCA9548_CHANNEL_COUNT];
     I2CBus *bus[PCA9548_CHANNEL_COUNT];
+
+    char *name;
 } Pca954xState;
 
 /*
@@ -181,6 +184,17 @@ static void pca9548_class_init(ObjectClass *klass, void *data)
     s->nchans = PCA9548_CHANNEL_COUNT;
 }
 
+static void pca954x_realize(DeviceState *dev, Error **errp)
+{
+    Pca954xState *s = PCA954X(dev);
+    DeviceState *d = DEVICE(s);
+    if (s->name) {
+        d->id = g_strdup(s->name);
+    } else {
+        d->id = g_strdup_printf("pca954x[%x]", s->parent.i2c.address);
+    }
+}
+
 static void pca954x_init(Object *obj)
 {
     Pca954xState *s = PCA954X(obj);
@@ -197,6 +211,11 @@ static void pca954x_init(Object *obj)
     }
 }
 
+static Property pca954x_props[] = {
+    DEFINE_PROP_STRING("name", Pca954xState, name),
+    DEFINE_PROP_END_OF_LIST()
+};
+
 static void pca954x_class_init(ObjectClass *klass, void *data)
 {
     I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass);
@@ -209,9 +228,12 @@ static void pca954x_class_init(ObjectClass *klass, void *data)
     rc->phases.enter = pca954x_enter_reset;
 
     dc->desc = "Pca954x i2c-mux";
+    dc->realize = pca954x_realize;
 
     k->write_data = pca954x_write_data;
     k->receive_byte = pca954x_read_byte;
+
+    device_class_set_props(dc, pca954x_props);
 }
 
 static const TypeInfo pca954x_info[] = {