[libcamera-devel] [PATCH 06/12] libcamera: deviceenumerator: add DeviceEnumeratorUdev class
Niklas Söderlund
niklas.soderlund at ragnatech.se
Sun Dec 23 00:00:35 CET 2018
Provide a DeviceEnumeratorUdev class which is a specialization
of DeviceEnumerator which uses udev to enumerate information in the
system.
Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
src/libcamera/deviceenumerator.cpp | 100 +++++++++++++++++++++++
src/libcamera/include/deviceenumerator.h | 15 ++++
2 files changed, 115 insertions(+)
diff --git a/src/libcamera/deviceenumerator.cpp b/src/libcamera/deviceenumerator.cpp
index b2f59017e94d14aa..f4c40bf0376ab453 100644
--- a/src/libcamera/deviceenumerator.cpp
+++ b/src/libcamera/deviceenumerator.cpp
@@ -6,6 +6,7 @@
*/
#include <fcntl.h>
+#include <libudev.h>
#include <sys/ioctl.h>
#include <unistd.h>
@@ -273,4 +274,103 @@ DeviceInfo *DeviceEnumerator::search(DeviceMatch &dm) const
return info;
}
+/* -----------------------------------------------------------------------------
+ * Enumerator Udev
+ */
+
+DeviceEnumeratorUdev::DeviceEnumeratorUdev()
+ : udev_(NULL)
+{
+}
+
+DeviceEnumeratorUdev::~DeviceEnumeratorUdev()
+{
+ if (udev_)
+ udev_unref(udev_);
+}
+
+int DeviceEnumeratorUdev::init()
+{
+ if (udev_)
+ return -EBUSY;
+
+ udev_ = udev_new();
+ if (!udev_)
+ return -ENODEV;
+
+ return 0;
+}
+
+int DeviceEnumeratorUdev::enumerate()
+{
+ struct udev_enumerate *udev_enum = NULL;
+ struct udev_list_entry *ents, *ent;
+ int ret;
+
+ udev_enum = udev_enumerate_new(udev_);
+ if (udev_enum == NULL)
+ return -ENOMEM;
+
+ ret = udev_enumerate_add_match_subsystem(udev_enum, "media");
+ if (ret < 0)
+ goto done;
+
+ ret = udev_enumerate_scan_devices(udev_enum);
+ if (ret < 0)
+ goto done;
+
+ ents = udev_enumerate_get_list_entry(udev_enum);
+ if (ents == NULL)
+ goto done;
+
+ udev_list_entry_foreach(ent, ents) {
+ struct udev_device *dev;
+ const char *devnode;
+ const char *syspath = udev_list_entry_get_name(ent);
+
+ dev = udev_device_new_from_syspath(udev_, syspath);
+ if (dev == NULL) {
+ LOG(Error) << "Failed to device for '" << syspath << "', skipping";
+ continue;
+ }
+
+ devnode = udev_device_get_devnode(dev);
+ if (devnode == NULL) {
+ udev_device_unref(dev);
+ ret = -ENODEV;
+ goto done;
+ }
+
+ addDevice(devnode);
+
+ udev_device_unref(dev);
+ }
+done:
+ udev_enumerate_unref(udev_enum);
+ return ret >= 0 ? 0 : ret;
+}
+
+int DeviceEnumeratorUdev::lookupDevnode(std::string &devnode, int major, int minor)
+{
+ struct udev_device *device;
+ const char *name;
+ dev_t devnum;
+ int ret = 0;
+
+ devnum = makedev(major, minor);
+ device = udev_device_new_from_devnum(udev_, 'c', devnum);
+ if (!device)
+ return -ENODEV;
+
+ name = udev_device_get_devnode(device);
+ if (name)
+ devnode = name;
+ else
+ ret = -ENODEV;
+
+ udev_device_unref(device);
+
+ return ret;
+}
+
} /* namespace libcamera */
diff --git a/src/libcamera/include/deviceenumerator.h b/src/libcamera/include/deviceenumerator.h
index cbe17774edb7fcc5..2c7ff3f336ba127d 100644
--- a/src/libcamera/include/deviceenumerator.h
+++ b/src/libcamera/include/deviceenumerator.h
@@ -78,6 +78,21 @@ private:
virtual int lookupDevnode(std::string &devnode, int major, int minor) = 0;
};
+class DeviceEnumeratorUdev: public DeviceEnumerator
+{
+public:
+ DeviceEnumeratorUdev();
+ ~DeviceEnumeratorUdev();
+
+ int init() final;
+ int enumerate() final;
+
+private:
+ struct udev *udev_;
+
+ int lookupDevnode(std::string &devnode, int major, int minor) final;
+};
+
} /* namespace libcamera */
#endif /* __LIBCAMERA_DEVICEENUMERATE_H__ */
--
2.20.1
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