| Message ID | 20220526133025.18746-1-laurent.pinchart@ideasonboard.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series |
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| Related | show |
Quoting Laurent Pinchart via libcamera-devel (2022-05-26 14:30:25) > Use the removable attribute exposed by the USB device in sysfs to infer > if the camera is an external (when removable) or front (when > non-removable) camera. This is likely not perfect as the removable > attribute is derived from ACPI data which may not always be accurate, > and non-ACPI platforms likely report all devices as removable. Still, > this is a first step upon which a better method could be built. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 33 +++++++++++++++++--- > 1 file changed, 28 insertions(+), 5 deletions(-) > > diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > index 2ebf2788c3b4..53b2f23ab029 100644 > --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > @@ -501,13 +501,36 @@ int UVCCameraData::init(MediaDevice *media) > > video_->bufferReady.connect(this, &UVCCameraData::bufferReady); > > - /* > - * \todo Find a way to tell internal and external UVC cameras apart. > - * Until then, treat all UVC cameras as external. > - */ > - properties_.set(properties::Location, properties::CameraLocationExternal); > properties_.set(properties::Model, utils::toAscii(media->model())); > > + /* > + * Derive the location from the device removable attribute in sysfs. > + * Non-removable devices are assumed to be front as we lack detailed > + * location information, and removable device are considered external. > + * > + * The sysfs removable attribute is derived from the ACPI _UPC attribute > + * if available, or from the USB hub descriptors otherwise. ACPI data > + * may not be very reliable, and the USB hub descriptors may not be > + * accurate on DT-based platforms. A heuristic may need to be > + * implemented later if too many devices end up being miscategorized. > + * > + * \todo Find a way to tell front and back devices apart. This could > + * come from the ACPI _PLD, but that may be even more unreliable than > + * the _UPC. > + */ > + properties::LocationEnum location = properties::CameraLocationExternal; > + std::ifstream file(video_->devicePath() + "/../removable"); I expected this devicePath() to be /dev/video0 ... but given the above, I presume it's mapping elsewhere. Is it guaranteed to map to the sysfs path? or do we need to build it with the information we have? Anyway, if it fails, it will fail to what we have anyway so - if it works in some cases, that's still 'progress'... With the path understood, (which I'm sure you do anyway...) Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> > + if (file.is_open()) { > + std::string value; > + std::getline(file, value); > + file.close(); > + > + if (value == "fixed") > + location = properties::CameraLocationFront; > + } > + > + properties_.set(properties::Location, location); > + > /* > * Get the current format in order to initialize the sensor array > * properties. > > base-commit: f8e4649680303ce9b7dace5ad1344fcb450013ac > prerequisite-patch-id: edbf31ed9d7f5374e17b34936fe1aa8dea2eac44 > -- > Regards, > > Laurent Pinchart >
On Thu, May 26, 2022 at 03:03:47PM +0100, Kieran Bingham wrote: > Quoting Laurent Pinchart via libcamera-devel (2022-05-26 14:30:25) > > Use the removable attribute exposed by the USB device in sysfs to infer > > if the camera is an external (when removable) or front (when > > non-removable) camera. This is likely not perfect as the removable > > attribute is derived from ACPI data which may not always be accurate, > > and non-ACPI platforms likely report all devices as removable. Still, > > this is a first step upon which a better method could be built. > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > --- > > src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 33 +++++++++++++++++--- > > 1 file changed, 28 insertions(+), 5 deletions(-) > > > > diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > > index 2ebf2788c3b4..53b2f23ab029 100644 > > --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > > +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > > @@ -501,13 +501,36 @@ int UVCCameraData::init(MediaDevice *media) > > > > video_->bufferReady.connect(this, &UVCCameraData::bufferReady); > > > > - /* > > - * \todo Find a way to tell internal and external UVC cameras apart. > > - * Until then, treat all UVC cameras as external. > > - */ > > - properties_.set(properties::Location, properties::CameraLocationExternal); > > properties_.set(properties::Model, utils::toAscii(media->model())); > > > > + /* > > + * Derive the location from the device removable attribute in sysfs. > > + * Non-removable devices are assumed to be front as we lack detailed > > + * location information, and removable device are considered external. > > + * > > + * The sysfs removable attribute is derived from the ACPI _UPC attribute > > + * if available, or from the USB hub descriptors otherwise. ACPI data > > + * may not be very reliable, and the USB hub descriptors may not be > > + * accurate on DT-based platforms. A heuristic may need to be > > + * implemented later if too many devices end up being miscategorized. > > + * > > + * \todo Find a way to tell front and back devices apart. This could > > + * come from the ACPI _PLD, but that may be even more unreliable than > > + * the _UPC. > > + */ > > + properties::LocationEnum location = properties::CameraLocationExternal; > > + std::ifstream file(video_->devicePath() + "/../removable"); > > I expected this devicePath() to be /dev/video0 ... but given the above, > I presume it's mapping elsewhere. Is it guaranteed to map to the sysfs > path? or do we need to build it with the information we have? Quoting https://libcamera.org/api-html/classlibcamera_1_1V4L2Device.html#a8454df564fffa7ad160468709aa172ff, "This function returns the sysfs path to the physical device backing the V4L2 device. The path is guaranteed to be an absolute path, without any symbolic link." So we're good :-) > Anyway, if it fails, it will fail to what we have anyway so - if it > works in some cases, that's still 'progress'... > > With the path understood, (which I'm sure you do anyway...) > > Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> > > > + if (file.is_open()) { > > + std::string value; > > + std::getline(file, value); > > + file.close(); > > + > > + if (value == "fixed") > > + location = properties::CameraLocationFront; > > + } > > + > > + properties_.set(properties::Location, location); > > + > > /* > > * Get the current format in order to initialize the sensor array > > * properties. > > > > base-commit: f8e4649680303ce9b7dace5ad1344fcb450013ac > > prerequisite-patch-id: edbf31ed9d7f5374e17b34936fe1aa8dea2eac44
Hi Laurent, On Thu, May 26, 2022 at 04:30:25PM +0300, Laurent Pinchart via libcamera-devel wrote: > Use the removable attribute exposed by the USB device in sysfs to infer > if the camera is an external (when removable) or front (when > non-removable) camera. This is likely not perfect as the removable > attribute is derived from ACPI data which may not always be accurate, > and non-ACPI platforms likely report all devices as removable. Still, > this is a first step upon which a better method could be built. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> > --- > src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 33 +++++++++++++++++--- > 1 file changed, 28 insertions(+), 5 deletions(-) > > diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > index 2ebf2788c3b4..53b2f23ab029 100644 > --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > @@ -501,13 +501,36 @@ int UVCCameraData::init(MediaDevice *media) > > video_->bufferReady.connect(this, &UVCCameraData::bufferReady); > > - /* > - * \todo Find a way to tell internal and external UVC cameras apart. > - * Until then, treat all UVC cameras as external. > - */ > - properties_.set(properties::Location, properties::CameraLocationExternal); > properties_.set(properties::Model, utils::toAscii(media->model())); > > + /* > + * Derive the location from the device removable attribute in sysfs. > + * Non-removable devices are assumed to be front as we lack detailed > + * location information, and removable device are considered external. > + * > + * The sysfs removable attribute is derived from the ACPI _UPC attribute > + * if available, or from the USB hub descriptors otherwise. ACPI data > + * may not be very reliable, and the USB hub descriptors may not be > + * accurate on DT-based platforms. A heuristic may need to be > + * implemented later if too many devices end up being miscategorized. > + * > + * \todo Find a way to tell front and back devices apart. This could > + * come from the ACPI _PLD, but that may be even more unreliable than > + * the _UPC. > + */ > + properties::LocationEnum location = properties::CameraLocationExternal; > + std::ifstream file(video_->devicePath() + "/../removable"); > + if (file.is_open()) { > + std::string value; > + std::getline(file, value); > + file.close(); > + > + if (value == "fixed") > + location = properties::CameraLocationFront; > + } > + > + properties_.set(properties::Location, location); > + > /* > * Get the current format in order to initialize the sensor array > * properties. > > base-commit: f8e4649680303ce9b7dace5ad1344fcb450013ac > prerequisite-patch-id: edbf31ed9d7f5374e17b34936fe1aa8dea2eac44
Hi Laurent, On Thu, 2022-05-26 at 16:30 +0300, Laurent Pinchart wrote: > Use the removable attribute exposed by the USB device in sysfs to infer > if the camera is an external (when removable) or front (when > non-removable) camera. This is likely not perfect as the removable > attribute is derived from ACPI data which may not always be accurate, > and non-ACPI platforms likely report all devices as removable. Still, > this is a first step upon which a better method could be built. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Thanks, this makes my internal laptop uvc webcam be reported properly as a "front" camera instead of an external one. Tested-by: George Kiagiadakis <george.kiagiadakis@collabora.com> > --- > src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 33 +++++++++++++++++--- > 1 file changed, 28 insertions(+), 5 deletions(-) > > diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > index 2ebf2788c3b4..53b2f23ab029 100644 > --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > @@ -501,13 +501,36 @@ int UVCCameraData::init(MediaDevice *media) > > video_->bufferReady.connect(this, &UVCCameraData::bufferReady); > > - /* > - * \todo Find a way to tell internal and external UVC cameras apart. > - * Until then, treat all UVC cameras as external. > - */ > - properties_.set(properties::Location, properties::CameraLocationExternal); > properties_.set(properties::Model, utils::toAscii(media->model())); > > + /* > + * Derive the location from the device removable attribute in sysfs. > + * Non-removable devices are assumed to be front as we lack detailed > + * location information, and removable device are considered external. > + * > + * The sysfs removable attribute is derived from the ACPI _UPC attribute > + * if available, or from the USB hub descriptors otherwise. ACPI data > + * may not be very reliable, and the USB hub descriptors may not be > + * accurate on DT-based platforms. A heuristic may need to be > + * implemented later if too many devices end up being miscategorized. > + * > + * \todo Find a way to tell front and back devices apart. This could > + * come from the ACPI _PLD, but that may be even more unreliable than > + * the _UPC. > + */ > + properties::LocationEnum location = properties::CameraLocationExternal; > + std::ifstream file(video_->devicePath() + "/../removable"); > + if (file.is_open()) { > + std::string value; > + std::getline(file, value); > + file.close(); > + > + if (value == "fixed") > + location = properties::CameraLocationFront; > + } > + > + properties_.set(properties::Location, location); > + > /* > * Get the current format in order to initialize the sensor array > * properties. > > base-commit: f8e4649680303ce9b7dace5ad1344fcb450013ac > prerequisite-patch-id: edbf31ed9d7f5374e17b34936fe1aa8dea2eac44
diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp index 2ebf2788c3b4..53b2f23ab029 100644 --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp @@ -501,13 +501,36 @@ int UVCCameraData::init(MediaDevice *media) video_->bufferReady.connect(this, &UVCCameraData::bufferReady); - /* - * \todo Find a way to tell internal and external UVC cameras apart. - * Until then, treat all UVC cameras as external. - */ - properties_.set(properties::Location, properties::CameraLocationExternal); properties_.set(properties::Model, utils::toAscii(media->model())); + /* + * Derive the location from the device removable attribute in sysfs. + * Non-removable devices are assumed to be front as we lack detailed + * location information, and removable device are considered external. + * + * The sysfs removable attribute is derived from the ACPI _UPC attribute + * if available, or from the USB hub descriptors otherwise. ACPI data + * may not be very reliable, and the USB hub descriptors may not be + * accurate on DT-based platforms. A heuristic may need to be + * implemented later if too many devices end up being miscategorized. + * + * \todo Find a way to tell front and back devices apart. This could + * come from the ACPI _PLD, but that may be even more unreliable than + * the _UPC. + */ + properties::LocationEnum location = properties::CameraLocationExternal; + std::ifstream file(video_->devicePath() + "/../removable"); + if (file.is_open()) { + std::string value; + std::getline(file, value); + file.close(); + + if (value == "fixed") + location = properties::CameraLocationFront; + } + + properties_.set(properties::Location, location); + /* * Get the current format in order to initialize the sensor array * properties.
Use the removable attribute exposed by the USB device in sysfs to infer if the camera is an external (when removable) or front (when non-removable) camera. This is likely not perfect as the removable attribute is derived from ACPI data which may not always be accurate, and non-ACPI platforms likely report all devices as removable. Still, this is a first step upon which a better method could be built. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> --- src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 33 +++++++++++++++++--- 1 file changed, 28 insertions(+), 5 deletions(-) base-commit: f8e4649680303ce9b7dace5ad1344fcb450013ac prerequisite-patch-id: edbf31ed9d7f5374e17b34936fe1aa8dea2eac44