Add a helper macro for the situations where a non-MC driver needs to
call a state-operation (operation which takes a subdev state as a
parameter) in try-context in another subdev.
The macro allocates a new subdev state for the called subdev and frees
the state afterwards.
An example use case is a media platform driver testing if a
v4l2_subdev_format would be accepted by a source subdev.
This should not be used in MC drivers.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
---
include/media/v4l2-subdev.h | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index b661e1817470..9689f38a0af1 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -1433,6 +1433,40 @@ extern const struct v4l2_subdev_ops v4l2_subdev_call_wrappers;
__result; \
})
+/**
+ * v4l2_subdev_call_state_try - call an operation of a v4l2_subdev which
+ * takes state as a parameter, passing the
+ * subdev a newly allocated try state.
+ *
+ * @sd: pointer to the &struct v4l2_subdev
+ * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
+ * Each element there groups a set of callbacks functions.
+ * @f: callback function to be called.
+ * The callback functions are defined in groups, according to
+ * each element at &struct v4l2_subdev_ops.
+ * @args: arguments for @f.
+ *
+ * This is similar to v4l2_subdev_call_state_active(), except that as this
+ * version allocates a new state, this is only usable for
+ * V4L2_SUBDEV_FORMAT_TRY use cases.
+ *
+ * Note: only legacy non-MC drivers may need this macro.
+ */
+#define v4l2_subdev_call_state_try(sd, o, f, args...) \
+ ({ \
+ int __result; \
+ static struct lock_class_key __key; \
+ const char *name = KBUILD_BASENAME \
+ ":" __stringify(__LINE__) ":state->lock"; \
+ struct v4l2_subdev_state *state = \
+ __v4l2_subdev_state_alloc(sd, name, &__key); \
+ v4l2_subdev_lock_state(state); \
+ __result = v4l2_subdev_call(sd, o, f, state, ##args); \
+ v4l2_subdev_unlock_state(state); \
+ __v4l2_subdev_state_free(state); \
+ __result; \
+ })
+
/**
* v4l2_subdev_has_op - Checks if a subdev defines a certain operation.
*
--
2.34.1
