From 0567d3ad75422c99e574a351dafb4f7a7447e0fe Mon Sep 17 00:00:00 2001
From: Phi-Bang Nguyen <pnguyen@baylibre.com>
Date: Thu, 11 Feb 2021 16:26:37 +0100
Subject: libcamera: v4l2_subdevice: Add VIDIOC_SUBDEV_G_ROUTING ioctl

Signed-off-by: Phi-Bang Nguyen <pnguyen@baylibre.com>
---
 src/libcamera/v4l2_subdevice.cpp | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

(limited to 'src')

diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
index 023e2328..a0cc5eb4 100644
--- a/src/libcamera/v4l2_subdevice.cpp
+++ b/src/libcamera/v4l2_subdevice.cpp
@@ -442,6 +442,46 @@ int V4L2Subdevice::setFormat(unsigned int pad, V4L2SubdeviceFormat *format,
 	return 0;
 }
 
+/**
+ * \brief Retrieve the subdevice's internal routing table
+ * \param[out] routes The routing table
+ * \param[in] whence The routing table to get, \ref V4L2Subdevice::ActiveFormat
+ * "ActiveFormat" or \ref V4L2Subdevice::TryFormat "TryFormat"
+ *
+ * \return 0 on success or a negative error code otherwise
+ */
+int V4L2Subdevice::getRouting(std::vector<struct v4l2_subdev_route> *routes,
+			      Whence whence)
+{
+	struct v4l2_subdev_routing rt = {};
+
+	rt.which = whence == ActiveFormat ? V4L2_SUBDEV_FORMAT_ACTIVE
+		 : V4L2_SUBDEV_FORMAT_TRY;
+
+	int ret = ioctl(VIDIOC_SUBDEV_G_ROUTING, &rt);
+	if (ret == 0 || ret == -ENOTTY)
+		return ret;
+
+	if (ret != -ENOSPC) {
+		LOG(V4L2, Error)
+			<< "Failed to retrieve number of routes: "
+			<< strerror(-ret);
+		return ret;
+	}
+
+	routes->resize(rt.num_routes);
+	rt.routes = reinterpret_cast<uintptr_t>(routes->data());
+
+	ret = ioctl(VIDIOC_SUBDEV_G_ROUTING, &rt);
+	if (ret) {
+		LOG(V4L2, Error)
+			<< "Failed to retrieve routes: " << strerror(-ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 /**
  * \brief Create a new video subdevice instance from \a entity in media device
  * \a media
-- 
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