Hi,
On 07/07/2022 13:27, Tomasz Figa wrote:
Hi Tomi, Laurent,
On Tue, Mar 01, 2022 at 06:11:54PM +0200, Tomi Valkeinen wrote:
From: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Add a helper function to translate streams between two pads of a subdev,
using the subdev's internal routing table.
Thanks for the patch! Please see my comments inline.
Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-subdev.c | 25 +++++++++++++++++++++++++
include/media/v4l2-subdev.h | 23 +++++++++++++++++++++++
2 files changed, 48 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index e30338a53088..6a9fc62dacbf 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -1529,6 +1529,31 @@ v4l2_subdev_state_get_opposite_stream_format(struct v4l2_subdev_state *state,
}
EXPORT_SYMBOL_GPL(v4l2_subdev_state_get_opposite_stream_format);
+u64 v4l2_subdev_state_xlate_streams(const struct v4l2_subdev_state *state,
+ u32 pad0, u32 pad1, u64 *streams)
+{
+ const struct v4l2_subdev_krouting *routing = &state->routing;
+ struct v4l2_subdev_route *route;
+ u64 streams0 = 0;
+ u64 streams1 = 0;
+
+ for_each_active_route(routing, route) {
+ if (route->sink_pad == pad0 && route->source_pad == pad1 &&
+ (*streams & BIT(route->sink_stream))) {
+ streams0 |= BIT(route->sink_stream);
+ streams1 |= BIT(route->source_stream);
+ }
+ if (route->source_pad == pad0 && route->sink_pad == pad1 &&
+ (*streams & BIT(route->source_stream))) {
+ streams0 |= BIT(route->source_stream);
+ streams1 |= BIT(route->sink_stream);
+ }
+ }
+
+ *streams = streams0;
+ return streams1;
+}
+
int v4l2_subdev_get_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_state *state,
struct v4l2_subdev_format *format)
{
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 1eced0f47296..992debe116ac 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -1497,6 +1497,29 @@ struct v4l2_mbus_framefmt *
v4l2_subdev_state_get_opposite_stream_format(struct v4l2_subdev_state *state,
u32 pad, u32 stream);
+/**
+ * v4l2_subdev_state_xlate_streams() - Translate streams from one pad to another
+ *
+ * @state: Subdevice state
+ * @pad0: The first pad
+ * @pad1: The second pad
+ * @streams: Streams bitmask on the first pad
+ *
+ * Streams on sink pads of a subdev are routed to source pads as expressed in
+ * the subdev state routing table. Stream numbers don't necessarily match on
+ * the sink and source side of a route. This function translates stream numbers
+ * on @pad0, expressed as a bitmask in @streams, to the corresponding streams
+ * on @pad1 using the routing table from the @state. It returns the stream mask
+ * on @pad1, and updates @streams with the streams that have been found in the
+ * routing table.
+ *
+ * @pad0 and @pad1 must be a sink and a source, in any order.
+ *
+ * Return: The bitmask of streams of @pad1 that are routed to @streams on @pad0.
It might be just me, but somehow I associate "translate" with turning a
name from one namespace into a corresponding name from another
namespace. In this case I initially assumed that this function is
supposed to accept stream IDs from pad0 and return corresponding
stream IDs from pad1. However, it looks like this is move like - "tell
me which streams on pad1 are connected to the given pad0 streams". Is
this correct?
So is your point that as the function returns a bitmask, and not a
mapping of the stream IDs, this is not a translate function?
If yes, maybe v4l2_subdev_state_get_routed_streams() be a better name?
I think this name would also fit quite well for a function that returns
a mapping of the streams. So... I don't have a strong opinion on this.
To me, neither the current name nor the proposed one clearly explains
alone what the function does.
Tomi
