Make the direction qdev_pass_gpios() pass the GPIOs more obvious
by renaming its arguments as 'from_dev' and 'to_container'.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 include/hw/qdev-core.h | 10 +++++-----
 hw/core/qdev.c         | 14 +++++++-------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index ea3f73a282d..c72d4db2d26 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -643,8 +643,8 @@ static inline void qdev_init_gpio_in_named(DeviceState *dev,
 
 /**
  * qdev_pass_gpios: create GPIO lines on container which pass through to device
- * @dev: Device which has GPIO lines
- * @container: Container device which needs to expose them
+ * @from_dev: Device which has GPIO lines
+ * @to_container: Container device which needs to expose them
  * @name: Name of GPIO array to pass through (NULL for the anonymous GPIO array)
  *
  * In QEMU, complicated devices like SoCs are often modelled with a
@@ -653,14 +653,14 @@ static inline void qdev_init_gpio_in_named(DeviceState *dev,
  * to create GPIO arrays on itself which simply pass through to a GPIO
  * array of one of its internal devices.
  *
- * If @dev has both input and output GPIOs named @name then both will
+ * If @from_dev has both input and output GPIOs named @name then both will
  * be passed through. It is not possible to pass a subset of the array
  * with this function.
  *
- * To users of the container device, the GPIO array created on @container
+ * To users of the container device, the GPIO array created on @to_container
  * behaves exactly like any other.
  */
-void qdev_pass_gpios(DeviceState *dev, DeviceState *container,
+void qdev_pass_gpios(DeviceState *from_dev, DeviceState *to_container,
                      const char *name);
 
 BusState *qdev_get_parent_bus(DeviceState *dev);
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 96772a15bd5..79cbd990114 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -576,30 +576,30 @@ void qdev_connect_gpio_out(DeviceState * dev, int n, qemu_irq pin)
     qdev_connect_gpio_out_named(dev, NULL, n, pin);
 }
 
-void qdev_pass_gpios(DeviceState *dev, DeviceState *container,
+void qdev_pass_gpios(DeviceState *from_dev, DeviceState *to_container,
                      const char *name)
 {
     int i;
-    NamedGPIOList *ngl = qdev_get_named_gpio_list(dev, name);
+    NamedGPIOList *ngl = qdev_get_named_gpio_list(from_dev, name);
 
     for (i = 0; i < ngl->num_in; i++) {
         const char *nm = ngl->name ? ngl->name : "unnamed-gpio-in";
         char *propname = g_strdup_printf("%s[%d]", nm, i);
 
-        object_property_add_alias(OBJECT(container), propname,
-                                  OBJECT(dev), propname);
+        object_property_add_alias(OBJECT(to_container), propname,
+                                  OBJECT(from_dev), propname);
         g_free(propname);
     }
     for (i = 0; i < ngl->num_out; i++) {
         const char *nm = ngl->name ? ngl->name : "unnamed-gpio-out";
         char *propname = g_strdup_printf("%s[%d]", nm, i);
 
-        object_property_add_alias(OBJECT(container), propname,
-                                  OBJECT(dev), propname);
+        object_property_add_alias(OBJECT(to_container), propname,
+                                  OBJECT(from_dev), propname);
         g_free(propname);
     }
     QLIST_REMOVE(ngl, node);
-    QLIST_INSERT_HEAD(&container->gpios, ngl, node);
+    QLIST_INSERT_HEAD(&to_container->gpios, ngl, node);
 }
 
 BusState *qdev_get_child_bus(DeviceState *dev, const char *name)
-- 
2.26.2

On Tue, 18 Aug 2020 at 15:38, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>
> Make the direction qdev_pass_gpios() pass the GPIOs more obvious
> by renaming its arguments as 'from_dev' and 'to_container'.
>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  include/hw/qdev-core.h | 10 +++++-----
>  hw/core/qdev.c         | 14 +++++++-------
>  2 files changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index ea3f73a282d..c72d4db2d26 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -643,8 +643,8 @@ static inline void qdev_init_gpio_in_named(DeviceState *dev,
>
>  /**
>   * qdev_pass_gpios: create GPIO lines on container which pass through to device

In the line above we say that the pass through is from the container
to the device...

> - * @dev: Device which has GPIO lines
> - * @container: Container device which needs to expose them
> + * @from_dev: Device which has GPIO lines
> + * @to_container: Container device which needs to expose them

...but here we say that it is from the device to the container.

You could make an argument for either convention of from/to,
but we should be consistent. The most useful part of the name
is the part we already have, because 'dev' vs 'container'
is unambiguous, whereas 'to' vs 'from' depends on your
point of view and doesn't really help in working out which
way round the arguments should go.

thanks
-- PMM