hw/i2c: Enable an id for the pca954x devices

Commit Message

Patrick Venture March 17, 2022, 11:53 p.m. UTC

This allows the devices to be more readily found and specified.
Without setting the id 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 id
'pca954x[77]', for an instance attached at that address.

Signed-off-by: Patrick Venture <[e-mail]>
Reviewed-by: Hao Wu <[e-mail]>
---
 hw/i2c/i2c_mux_pca954x.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

Patch

diff --git a/hw/i2c/i2c_mux_pca954x.c b/hw/i2c/i2c_mux_pca954x.c
index a9517b612a..4f8c2d6ae1 100644
--- a/hw/i2c/i2c_mux_pca954x.c
+++ b/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 *id;
 } 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->id) {
+        d->id = g_strdup(s->id);
+    } 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("id", Pca954xState, id),
+    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[] = {