| Message ID | 20200728234225.3505868-2-niklas.soderlund@ragnatech.se |
|---|---|
| State | Superseded |
| Headers | show |
| Series |
|
| Related | show |
Hi Niklas, On Wed, Jul 29, 2020 at 01:42:22AM +0200, Niklas Söderlund wrote: > Generate a constant and unique string ID for the sensor. The ID is > generated from firmware information fetched from the hardware that backs > the sensor. The ID is unique and persistent across reboots of the nit: I would drop "fetched from the hardwaware ..." and replace it with "from the firwmare descritpion of the camera image sensor". > system. > > For OF based systems the ID is the full path of the sensors in the > device tree description. For ACPI bases systems the ID is the ACPI s/bases/based/ > firmware nodes path. Both ID sources are guaranteed to be unique and > persistent as long as the firmware of the system is not changed. > > A special case is needed to deal with the VIMC pipeline that implements > a virtual pipeline that is not backed by any hardware device and is > therefore not described in the device firmware. > > Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> > --- > include/libcamera/internal/camera_sensor.h | 4 + > src/libcamera/camera_sensor.cpp | 85 ++++++++++++++++++++++ > 2 files changed, 89 insertions(+) > > diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h > index 06c8292ca30129de..e0d2d9f63b47c2fe 100644 > --- a/include/libcamera/internal/camera_sensor.h > +++ b/include/libcamera/internal/camera_sensor.h > @@ -47,6 +47,7 @@ public: > int init(); > > const std::string &model() const { return model_; } > + const std::string &id() const { return id_; } > const MediaEntity *entity() const { return entity_; } > const std::vector<unsigned int> &mbusCodes() const { return mbusCodes_; } > const std::vector<Size> &sizes() const { return sizes_; } > @@ -67,11 +68,14 @@ protected: > std::string logPrefix() const override; > > private: > + int generateID(); > + > const MediaEntity *entity_; > std::unique_ptr<V4L2Subdevice> subdev_; > unsigned int pad_; > > std::string model_; > + std::string id_; > > V4L2Subdevice::Formats formats_; > Size resolution_; > diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp > index 350f49accad99c7b..a4339759bc847ff0 100644 > --- a/src/libcamera/camera_sensor.cpp > +++ b/src/libcamera/camera_sensor.cpp > @@ -9,10 +9,12 @@ > > #include <algorithm> > #include <float.h> > +#include <fstream> > #include <iomanip> > #include <limits.h> > #include <math.h> > #include <regex> > +#include <sys/stat.h> > > #include <libcamera/property_ids.h> > > @@ -204,6 +206,11 @@ int CameraSensor::init() > if (ret < 0) > return ret; > > + /* Generate a unique ID for the sensor. */ > + ret = generateID(); > + if (ret) > + return ret; > + > /* Retrieve and store the camera sensor properties. */ > const ControlInfoMap &controls = subdev_->controls(); > int32_t propertyValue; > @@ -283,6 +290,17 @@ int CameraSensor::init() > * \return The sensor model name > */ > > +/** > + * \fn CameraSensor::id() > + * \brief Retrieve the sensor ID > + * > + * The sensor ID is a free-formed string that uniquely identifies the sensor in > + * the system. The ID is persisted between different instances of libcamera and s/persisted/persistent/ > + * between resets of the system. You know, I would copy part of the commit message here that tells how a sensor ID is composed. > + * > + * \return The sensor ID > + */ > + > /** > * \fn CameraSensor::entity() > * \brief Retrieve the sensor media entity > @@ -541,4 +559,71 @@ std::string CameraSensor::logPrefix() const > return "'" + entity_->name() + "'"; > } > > +int CameraSensor::generateID() > +{ > + std::string path, devPath = subdev_->devicePath(); nit: can devPath be a const reference ? > + struct stat statbuf; > + > + /* Try to generate ID from OF device tree path. */ > + path = devPath + "/of_node"; > + if (stat(path.c_str(), &statbuf) == 0) { > + char ofPath[PATH_MAX]; > + > + if (!realpath(path.c_str(), ofPath)) { > + LOG(CameraSensor, Error) << "Failed to read sensor OF based ID"; > + return -EINVAL; > + } > + > + id_ = ofPath; > + const std::string dropStr = "/sys/firmware/devicetree/"; Have you considered dropping '/base' too ? > + if (id_.find(dropStr) == 0) > + id_.erase(0, dropStr.length()); > + > + return 0; > + } > + > + /* Try to generate ID from ACPI path. */ > + path = devPath + "/firmware_node/path"; > + if (stat(path.c_str(), &statbuf) == 0) { > + std::ifstream file(path.c_str()); > + > + if (!file.is_open()) { > + LOG(CameraSensor, Error) << "Failed to read sensor ACPI based ID"; > + return -EINVAL; > + } > + > + std::getline(file, id_); > + file.close(); > + > + return 0; > + } I'm now worried about file permission. Opening a file in RO mode would help avoiding permission issues ? > + > + /* > + * VIMC is a virtual video pipeline not backed hardware and have no OF > + * or ACPI firmware nodes. Handle this pipeline as a special case and > + * generate IDs based on the sensor model. > + */ > + path = devPath + "/modalias"; > + if (stat(path.c_str(), &statbuf) == 0) { > + std::ifstream file(path.c_str()); > + > + if (!file.is_open()) { > + LOG(CameraSensor, Error) << "Failed to read sensor ACPI based ID"; > + return -EINVAL; > + } > + > + std::string modalias; > + std::getline(file, modalias); > + file.close(); > + > + if (modalias == "platform:vimc") { > + id_ = "VIMC " + model(); > + return 0; > + } > + } > + > + LOG(CameraSensor, Error) << "Unknown sensor device type, can not generate ID"; I would however set id_ to a default. Maybe with an increasing counter appended. This looks very nice to me and a really good way to address this thorny issue Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Thanks j > + return -EINVAL; > +} > + > } /* namespace libcamera */ > -- > 2.27.0 > > _______________________________________________ > libcamera-devel mailing list > libcamera-devel@lists.libcamera.org > https://lists.libcamera.org/listinfo/libcamera-devel
Hi Jacopo, Thanks for your feedback. On 2020-07-29 09:56:44 +0200, Jacopo Mondi wrote: > Hi Niklas, > > On Wed, Jul 29, 2020 at 01:42:22AM +0200, Niklas Söderlund wrote: > > Generate a constant and unique string ID for the sensor. The ID is > > generated from firmware information fetched from the hardware that backs > > the sensor. The ID is unique and persistent across reboots of the > > nit: I would drop "fetched from the hardwaware ..." and replace it > with "from the firwmare descritpion of the camera image sensor". > > > system. > > > > For OF based systems the ID is the full path of the sensors in the > > device tree description. For ACPI bases systems the ID is the ACPI > > s/bases/based/ > > > firmware nodes path. Both ID sources are guaranteed to be unique and > > persistent as long as the firmware of the system is not changed. > > > > A special case is needed to deal with the VIMC pipeline that implements > > a virtual pipeline that is not backed by any hardware device and is > > therefore not described in the device firmware. > > > > Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> > > --- > > include/libcamera/internal/camera_sensor.h | 4 + > > src/libcamera/camera_sensor.cpp | 85 ++++++++++++++++++++++ > > 2 files changed, 89 insertions(+) > > > > diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h > > index 06c8292ca30129de..e0d2d9f63b47c2fe 100644 > > --- a/include/libcamera/internal/camera_sensor.h > > +++ b/include/libcamera/internal/camera_sensor.h > > @@ -47,6 +47,7 @@ public: > > int init(); > > > > const std::string &model() const { return model_; } > > + const std::string &id() const { return id_; } > > const MediaEntity *entity() const { return entity_; } > > const std::vector<unsigned int> &mbusCodes() const { return mbusCodes_; } > > const std::vector<Size> &sizes() const { return sizes_; } > > @@ -67,11 +68,14 @@ protected: > > std::string logPrefix() const override; > > > > private: > > + int generateID(); > > + > > const MediaEntity *entity_; > > std::unique_ptr<V4L2Subdevice> subdev_; > > unsigned int pad_; > > > > std::string model_; > > + std::string id_; > > > > V4L2Subdevice::Formats formats_; > > Size resolution_; > > diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp > > index 350f49accad99c7b..a4339759bc847ff0 100644 > > --- a/src/libcamera/camera_sensor.cpp > > +++ b/src/libcamera/camera_sensor.cpp > > @@ -9,10 +9,12 @@ > > > > #include <algorithm> > > #include <float.h> > > +#include <fstream> > > #include <iomanip> > > #include <limits.h> > > #include <math.h> > > #include <regex> > > +#include <sys/stat.h> > > > > #include <libcamera/property_ids.h> > > > > @@ -204,6 +206,11 @@ int CameraSensor::init() > > if (ret < 0) > > return ret; > > > > + /* Generate a unique ID for the sensor. */ > > + ret = generateID(); > > + if (ret) > > + return ret; > > + > > /* Retrieve and store the camera sensor properties. */ > > const ControlInfoMap &controls = subdev_->controls(); > > int32_t propertyValue; > > @@ -283,6 +290,17 @@ int CameraSensor::init() > > * \return The sensor model name > > */ > > > > +/** > > + * \fn CameraSensor::id() > > + * \brief Retrieve the sensor ID > > + * > > + * The sensor ID is a free-formed string that uniquely identifies the sensor in > > + * the system. The ID is persisted between different instances of libcamera and > > s/persisted/persistent/ > > > + * between resets of the system. > > You know, I would copy part of the commit message here that tells how > a sensor ID is composed. > > > + * > > + * \return The sensor ID > > + */ > > + > > /** > > * \fn CameraSensor::entity() > > * \brief Retrieve the sensor media entity > > @@ -541,4 +559,71 @@ std::string CameraSensor::logPrefix() const > > return "'" + entity_->name() + "'"; > > } > > > > +int CameraSensor::generateID() > > +{ > > + std::string path, devPath = subdev_->devicePath(); > > nit: can devPath be a const reference ? No, devicePath() returns a value and not a reference. > > > + struct stat statbuf; > > + > > + /* Try to generate ID from OF device tree path. */ > > + path = devPath + "/of_node"; > > + if (stat(path.c_str(), &statbuf) == 0) { > > + char ofPath[PATH_MAX]; > > + > > + if (!realpath(path.c_str(), ofPath)) { > > + LOG(CameraSensor, Error) << "Failed to read sensor OF based ID"; > > + return -EINVAL; > > + } > > + > > + id_ = ofPath; > > + const std::string dropStr = "/sys/firmware/devicetree/"; > > Have you considered dropping '/base' too ? I thought about it but decided again it. If we ever get proper runtime DT overlay support which could used to add cameras at runtime we need to keep the /base prefix to distinguish it as far as I understand it. > > > + if (id_.find(dropStr) == 0) > > + id_.erase(0, dropStr.length()); > > + > > + return 0; > > + } > > + > > + /* Try to generate ID from ACPI path. */ > > + path = devPath + "/firmware_node/path"; > > + if (stat(path.c_str(), &statbuf) == 0) { > > + std::ifstream file(path.c_str()); > > + > > + if (!file.is_open()) { > > + LOG(CameraSensor, Error) << "Failed to read sensor ACPI based ID"; > > + return -EINVAL; > > + } > > + > > + std::getline(file, id_); > > + file.close(); > > + > > + return 0; > > + } > > I'm now worried about file permission. Opening a file in RO mode would > help avoiding permission issues ? std::ifstream is RO :-) > > > + > > + /* > > + * VIMC is a virtual video pipeline not backed hardware and have no OF > > + * or ACPI firmware nodes. Handle this pipeline as a special case and > > + * generate IDs based on the sensor model. > > + */ > > + path = devPath + "/modalias"; > > + if (stat(path.c_str(), &statbuf) == 0) { > > + std::ifstream file(path.c_str()); > > + > > + if (!file.is_open()) { > > + LOG(CameraSensor, Error) << "Failed to read sensor ACPI based ID"; > > + return -EINVAL; > > + } > > + > > + std::string modalias; > > + std::getline(file, modalias); > > + file.close(); > > + > > + if (modalias == "platform:vimc") { > > + id_ = "VIMC " + model(); > > + return 0; > > + } > > + } > > + > > + LOG(CameraSensor, Error) << "Unknown sensor device type, can not generate ID"; > > I would however set id_ to a default. Maybe with an increasing counter > appended. I think that is a bad idea, here we error out with -EINVAL and as this is a private function the only caller is CameraSensor::init() which will propagate the error. I don't think its a good idea to hide and try to recover if we encounter a new device type, what would that even be? Maybe we should even make the error fatal as it really should not happen. > > This looks very nice to me and a really good way to address this > thorny issue > > Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Thanks! > > Thanks > j > > > + return -EINVAL; > > +} > > + > > } /* namespace libcamera */ > > -- > > 2.27.0 > > > > _______________________________________________ > > libcamera-devel mailing list > > libcamera-devel@lists.libcamera.org > > https://lists.libcamera.org/listinfo/libcamera-devel
diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h index 06c8292ca30129de..e0d2d9f63b47c2fe 100644 --- a/include/libcamera/internal/camera_sensor.h +++ b/include/libcamera/internal/camera_sensor.h @@ -47,6 +47,7 @@ public: int init(); const std::string &model() const { return model_; } + const std::string &id() const { return id_; } const MediaEntity *entity() const { return entity_; } const std::vector<unsigned int> &mbusCodes() const { return mbusCodes_; } const std::vector<Size> &sizes() const { return sizes_; } @@ -67,11 +68,14 @@ protected: std::string logPrefix() const override; private: + int generateID(); + const MediaEntity *entity_; std::unique_ptr<V4L2Subdevice> subdev_; unsigned int pad_; std::string model_; + std::string id_; V4L2Subdevice::Formats formats_; Size resolution_; diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp index 350f49accad99c7b..a4339759bc847ff0 100644 --- a/src/libcamera/camera_sensor.cpp +++ b/src/libcamera/camera_sensor.cpp @@ -9,10 +9,12 @@ #include <algorithm> #include <float.h> +#include <fstream> #include <iomanip> #include <limits.h> #include <math.h> #include <regex> +#include <sys/stat.h> #include <libcamera/property_ids.h> @@ -204,6 +206,11 @@ int CameraSensor::init() if (ret < 0) return ret; + /* Generate a unique ID for the sensor. */ + ret = generateID(); + if (ret) + return ret; + /* Retrieve and store the camera sensor properties. */ const ControlInfoMap &controls = subdev_->controls(); int32_t propertyValue; @@ -283,6 +290,17 @@ int CameraSensor::init() * \return The sensor model name */ +/** + * \fn CameraSensor::id() + * \brief Retrieve the sensor ID + * + * The sensor ID is a free-formed string that uniquely identifies the sensor in + * the system. The ID is persisted between different instances of libcamera and + * between resets of the system. + * + * \return The sensor ID + */ + /** * \fn CameraSensor::entity() * \brief Retrieve the sensor media entity @@ -541,4 +559,71 @@ std::string CameraSensor::logPrefix() const return "'" + entity_->name() + "'"; } +int CameraSensor::generateID() +{ + std::string path, devPath = subdev_->devicePath(); + struct stat statbuf; + + /* Try to generate ID from OF device tree path. */ + path = devPath + "/of_node"; + if (stat(path.c_str(), &statbuf) == 0) { + char ofPath[PATH_MAX]; + + if (!realpath(path.c_str(), ofPath)) { + LOG(CameraSensor, Error) << "Failed to read sensor OF based ID"; + return -EINVAL; + } + + id_ = ofPath; + const std::string dropStr = "/sys/firmware/devicetree/"; + if (id_.find(dropStr) == 0) + id_.erase(0, dropStr.length()); + + return 0; + } + + /* Try to generate ID from ACPI path. */ + path = devPath + "/firmware_node/path"; + if (stat(path.c_str(), &statbuf) == 0) { + std::ifstream file(path.c_str()); + + if (!file.is_open()) { + LOG(CameraSensor, Error) << "Failed to read sensor ACPI based ID"; + return -EINVAL; + } + + std::getline(file, id_); + file.close(); + + return 0; + } + + /* + * VIMC is a virtual video pipeline not backed hardware and have no OF + * or ACPI firmware nodes. Handle this pipeline as a special case and + * generate IDs based on the sensor model. + */ + path = devPath + "/modalias"; + if (stat(path.c_str(), &statbuf) == 0) { + std::ifstream file(path.c_str()); + + if (!file.is_open()) { + LOG(CameraSensor, Error) << "Failed to read sensor ACPI based ID"; + return -EINVAL; + } + + std::string modalias; + std::getline(file, modalias); + file.close(); + + if (modalias == "platform:vimc") { + id_ = "VIMC " + model(); + return 0; + } + } + + LOG(CameraSensor, Error) << "Unknown sensor device type, can not generate ID"; + return -EINVAL; +} + } /* namespace libcamera */
Generate a constant and unique string ID for the sensor. The ID is generated from firmware information fetched from the hardware that backs the sensor. The ID is unique and persistent across reboots of the system. For OF based systems the ID is the full path of the sensors in the device tree description. For ACPI bases systems the ID is the ACPI firmware nodes path. Both ID sources are guaranteed to be unique and persistent as long as the firmware of the system is not changed. A special case is needed to deal with the VIMC pipeline that implements a virtual pipeline that is not backed by any hardware device and is therefore not described in the device firmware. Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> --- include/libcamera/internal/camera_sensor.h | 4 + src/libcamera/camera_sensor.cpp | 85 ++++++++++++++++++++++ 2 files changed, 89 insertions(+)