[RFC PATCH 02/17] hw/misc/temp-sensor: Add 'query-temperature-sensors' QMP command

[Philippe Mathieu-Daudé]

Add a command to query current temperature from all sensors able
to report it:

  { "execute": "query-temperature-sensors" }
  {
      "return": [
          {
              "temperature": 25,
              "name": "videocore"
          },
          {
              "temperature": 25,
              "name": "bcm2835-thermal-0"
          }
      ]
  }

Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
 qapi/misc.json        | 24 ++++++++++++++++++++++
 hw/misc/temp-sensor.c | 48 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/qapi/misc.json b/qapi/misc.json
index 99b90ac80b..51881931e2 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -1550,3 +1550,27 @@
 ##
 { 'command': 'query-vm-generation-id', 'returns': 'GuidInfo' }
 
+##
+# @TemperatureSensor:
+#
+# Temperature sensor information.
+#
+# @name: the name of the sensor
+#
+# @temperature: the current temperature of the sensor (in C)
+#
+# Since: 5.1
+##
+{ 'struct': 'TemperatureSensor',
+  'data': { 'name': 'str',
+            'temperature': 'number' } }
+
+##
+# @query-temperature-sensors:
+#
+# Return a list of TemperatureSensor for devices that support
+# the TYPE_TEMPSENSOR_INTERFACE.
+#
+# Since: 5.1
+##
+{ 'command': 'query-temperature-sensors', 'returns': ['TemperatureSensor']}
diff --git a/hw/misc/temp-sensor.c b/hw/misc/temp-sensor.c
index b7c1eb2d87..27750c533d 100644
--- a/hw/misc/temp-sensor.c
+++ b/hw/misc/temp-sensor.c
@@ -10,6 +10,54 @@
 
 #include "qemu/osdep.h"
 #include "hw/misc/temp-sensor.h"
+#include "qapi/qapi-commands-misc.h"
+#include "qapi/error.h"
+
+static int query_temperature_sensors_foreach(Object *obj, void *opaque)
+{
+    TemperatureSensorList **list = opaque;
+    TempSensor *sensor;
+    TempSensorClass *k;
+
+    if (!object_dynamic_cast(obj, TYPE_TEMPSENSOR_INTERFACE)) {
+        return 0;
+    }
+
+    k = TEMPSENSOR_INTERFACE_GET_CLASS(obj);
+    if (!k->get_temperature) {
+        return 0;
+    }
+
+    sensor = TEMPSENSOR_INTERFACE(obj);
+    for (size_t i = 0; i < k->sensor_count; i++) {
+        TemperatureSensorList *info = g_malloc0(sizeof(*info));
+        TemperatureSensor *value = g_malloc0(sizeof(*value));
+
+        if (k->get_name) {
+            value->name = g_strdup(k->get_name(sensor, i));
+        } else {
+            value->name = g_strdup_printf("%s-%zu",
+                                          object_get_typename(obj), i);
+        }
+        value->temperature = k->get_temperature(sensor, i);
+
+        info->value = value;
+        info->next = *list;
+        *list = info;
+    }
+
+    return 0;
+}
+
+TemperatureSensorList *qmp_query_temperature_sensors(Error **errp)
+{
+    TemperatureSensorList *list = NULL;
+
+    object_child_foreach_recursive(object_get_root(),
+                                   query_temperature_sensors_foreach,
+                                   &list);
+    return list;
+}
 
 static TypeInfo tempsensor_interface_type_info = {
     .name = TYPE_TEMPSENSOR_INTERFACE,
-- 
2.21.1