[Qemu-devel] [RFC PATCH v2 05/12] Add function to control reset with gpio inputs

[Damien Hedde <damien.hedde@greensocs.com>]

It adds the possibility to add 2 gpios to control the warm and cold reset.
With theses ios, the reset can be maintained during some time.
Each io is associated with a state to detect level changes.

The cold reset io function is named power_gate as it is really the
meaning of this io.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
---
 hw/core/qdev.c         | 57 ++++++++++++++++++++++++++++++++++++++++++
 include/hw/qdev-core.h | 44 ++++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+)

diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 8c3911c2bd..89405398ae 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -429,6 +429,61 @@ void qdev_init_gpio_in(DeviceState *dev, qemu_irq_handler handler, int n)
     qdev_init_gpio_in_named(dev, handler, NULL, n);
 }
 
+static void device_reset_handler(DeviceState *dev, bool cold, bool level)
+{
+    DeviceResetInputState *dris;
+
+    dris = cold ? &dev->cold_reset_input : &dev->warm_reset_input;
+
+    if (level == dris->state) {
+        /* io state has not changed */
+        return;
+    }
+
+    dris->state = level;
+    switch (dris->type) {
+    case DEVICE_ACTIVE_LOW:
+        level = !level;
+    case DEVICE_ACTIVE_HIGH:
+        if (level) {
+            resettable_assert_reset(OBJECT(dev), cold);
+        } else {
+            resettable_deassert_reset(OBJECT(dev));
+        }
+        break;
+    }
+}
+
+static void device_cold_reset_handler(void *opaque, int n, int level)
+{
+    device_reset_handler((DeviceState *) opaque, true, level);
+}
+
+static void device_warm_reset_handler(void *opaque, int n, int level)
+{
+    device_reset_handler((DeviceState *) opaque, false, level);
+}
+
+void qdev_init_reset_gpio_in_named(DeviceState *dev, const char *name,
+                                   bool cold, DeviceActiveType type)
+{
+    qemu_irq_handler handler;
+
+    if (cold) {
+        assert(!dev->cold_reset_input.exists);
+        dev->cold_reset_input.exists = true;
+        dev->cold_reset_input.type = type;
+        handler = device_cold_reset_handler;
+    } else {
+        assert(!dev->warm_reset_input.exists);
+        dev->warm_reset_input.exists = true;
+        dev->warm_reset_input.type = type;
+        handler = device_warm_reset_handler;
+    }
+
+    qdev_init_gpio_in_named(dev, handler, name, 1);
+}
+
 void qdev_init_gpio_out_named(DeviceState *dev, qemu_irq *pins,
                               const char *name, int n)
 {
@@ -986,6 +1041,8 @@ static void device_initfn(Object *obj)
     dev->instance_id_alias = -1;
     dev->realized = false;
     dev->resetting = 0;
+    dev->cold_reset_input.exists = false;
+    dev->warm_reset_input.exists = false;
 
     object_property_add_bool(obj, "realized",
                              device_get_realized, device_set_realized, NULL);
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 658a419350..693f79b385 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -134,6 +134,17 @@ struct NamedGPIOList {
     QLIST_ENTRY(NamedGPIOList) node;
 };
 
+typedef enum DeviceActiveType {
+    DEVICE_ACTIVE_LOW,
+    DEVICE_ACTIVE_HIGH,
+} DeviceActiveType;
+
+typedef struct DeviceResetInputState {
+    bool exists;
+    DeviceActiveType type;
+    bool state;
+} DeviceResetInputState;
+
 /**
  * DeviceState:
  * @realized: Indicates whether the device has been fully constructed.
@@ -161,6 +172,8 @@ struct DeviceState {
     int instance_id_alias;
     int alias_required_for_version;
     uint32_t resetting;
+    DeviceResetInputState cold_reset_input;
+    DeviceResetInputState warm_reset_input;
 };
 
 struct DeviceListener {
@@ -362,6 +375,37 @@ static inline void qdev_init_gpio_in_named(DeviceState *dev,
 void qdev_pass_gpios(DeviceState *dev, DeviceState *container,
                      const char *name);
 
+/**
+ * qdev_init_reset_gpio_in_named:
+ * Create a gpio controlling the warm or cold reset of the device.
+ * @cold specify whether it triggers cold or warm reset
+ * @type what kind of reset io it is
+ */
+void qdev_init_reset_gpio_in_named(DeviceState *dev, const char *name,
+                                   bool cold, DeviceActiveType type);
+
+/**
+ * qdev_init_warm_reset_gpio:
+ * Create a reset input to control the device warm reset.
+ */
+static inline void qdev_init_warm_reset_gpio(DeviceState *dev,
+                                             const char *name,
+                                             DeviceActiveType type)
+{
+    qdev_init_reset_gpio_in_named(dev, name, false, type);
+}
+
+/**
+ * qdev_init_power_gate_gpio:
+ * Create a power gate input to control the device cold reset.
+ */
+static inline void qdev_init_power_gate_gpio(DeviceState *dev,
+                                             const char *name,
+                                             DeviceActiveType type)
+{
+    qdev_init_reset_gpio_in_named(dev, name, true, type);
+}
+
 BusState *qdev_get_parent_bus(DeviceState *dev);
 
 /*** BUS API. ***/
-- 
2.21.0