diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libcamera/include/v4l2_device.h | 9 | ||||
| -rw-r--r-- | src/libcamera/v4l2_device.cpp | 190 |
2 files changed, 199 insertions, 0 deletions
diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h index 55696046..24a0134a 100644 --- a/src/libcamera/include/v4l2_device.h +++ b/src/libcamera/include/v4l2_device.h @@ -10,11 +10,14 @@ #include <map> #include <string> +#include <linux/videodev2.h> + #include "log.h" namespace libcamera { class V4L2ControlInfo; +class V4L2ControlList; class V4L2Device : protected Loggable { @@ -23,6 +26,8 @@ public: bool isOpen() const { return fd_ != -1; } const V4L2ControlInfo *getControlInfo(unsigned int id) const; + int getControls(V4L2ControlList *ctrls); + int setControls(V4L2ControlList *ctrls); const std::string &deviceNode() const { return deviceNode_; } @@ -38,6 +43,10 @@ protected: private: void listControls(); + void updateControls(V4L2ControlList *ctrls, + const V4L2ControlInfo **controlInfo, + const struct v4l2_ext_control *v4l2Ctrls, + unsigned int count); std::map<unsigned int, V4L2ControlInfo> controls_; std::string deviceNode_; diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp index 51764b44..84758a81 100644 --- a/src/libcamera/v4l2_device.cpp +++ b/src/libcamera/v4l2_device.cpp @@ -126,6 +126,163 @@ const V4L2ControlInfo *V4L2Device::getControlInfo(unsigned int id) const } /** + * \brief Read controls from the device + * \param[inout] ctrls The list of controls to read + * + * This method reads the value of all controls contained in \a ctrls, and stores + * their values in the corresponding \a ctrls entry. + * + * If any control in \a ctrls is not supported by the device, is disabled (i.e. + * has the V4L2_CTRL_FLAG_DISABLED flag set), is a compound control, or if any + * other error occurs during validation of the requested controls, no control is + * read and this method returns -EINVAL. + * + * If an error occurs while reading the controls, the index of the first control + * that couldn't be read is returned. The value of all controls below that index + * are updated in \a ctrls, while the value of all the other controls are not + * changed. + * + * \return 0 on success or an error code otherwise + * \retval -EINVAL One of the control is not supported or not accessible + * \retval i The index of the control that failed + */ +int V4L2Device::getControls(V4L2ControlList *ctrls) +{ + unsigned int count = ctrls->size(); + if (count == 0) + return 0; + + const V4L2ControlInfo *controlInfo[count] = {}; + struct v4l2_ext_control v4l2Ctrls[count] = {}; + for (unsigned int i = 0; i < count; ++i) { + const V4L2Control *ctrl = ctrls->getByIndex(i); + const V4L2ControlInfo *info = getControlInfo(ctrl->id()); + if (!info) { + LOG(V4L2, Error) + << "Control '" << ctrl->id() << "' not found"; + return -EINVAL; + } + + controlInfo[i] = info; + v4l2Ctrls[i].id = info->id(); + } + + struct v4l2_ext_controls v4l2ExtCtrls = {}; + v4l2ExtCtrls.which = V4L2_CTRL_WHICH_CUR_VAL; + v4l2ExtCtrls.controls = v4l2Ctrls; + v4l2ExtCtrls.count = count; + + int ret = ioctl(VIDIOC_G_EXT_CTRLS, &v4l2ExtCtrls); + if (ret) { + unsigned int errorIdx = v4l2ExtCtrls.error_idx; + + /* Generic validation error. */ + if (errorIdx == 0 || errorIdx >= count) { + LOG(V4L2, Error) << "Unable to read controls: " + << strerror(ret); + return -EINVAL; + } + + /* A specific control failed. */ + LOG(V4L2, Error) << "Unable to read control " << errorIdx + << ": " << strerror(ret); + count = errorIdx - 1; + ret = errorIdx; + } + + updateControls(ctrls, controlInfo, v4l2Ctrls, count); + + return ret; +} + +/** + * \brief Write controls to the device + * \param[in] ctrls The list of controls to write + * + * This method writes the value of all controls contained in \a ctrls, and + * stores the values actually applied to the device in the corresponding + * \a ctrls entry. + * + * If any control in \a ctrls is not supported by the device, is disabled (i.e. + * has the V4L2_CTRL_FLAG_DISABLED flag set), is read-only, is a + * compound control, or if any other error occurs during validation of + * the requested controls, no control is written and this method returns + * -EINVAL. + * + * If an error occurs while writing the controls, the index of the first + * control that couldn't be written is returned. All controls below that index + * are written and their values are updated in \a ctrls, while all other + * controls are not written and their values are not changed. + * + * \return 0 on success or an error code otherwise + * \retval -EINVAL One of the control is not supported or not accessible + * \retval i The index of the control that failed + */ +int V4L2Device::setControls(V4L2ControlList *ctrls) +{ + unsigned int count = ctrls->size(); + if (count == 0) + return 0; + + const V4L2ControlInfo *controlInfo[count] = {}; + struct v4l2_ext_control v4l2Ctrls[count] = {}; + + for (unsigned int i = 0; i < count; ++i) { + const V4L2Control *ctrl = ctrls->getByIndex(i); + const V4L2ControlInfo *info = getControlInfo(ctrl->id()); + if (!info) { + LOG(V4L2, Error) + << "Control '" << ctrl->id() << "' not found"; + return -EINVAL; + } + + controlInfo[i] = info; + v4l2Ctrls[i].id = info->id(); + + /* Set the v4l2_ext_control value for the write operation. */ + switch (info->type()) { + case V4L2_CTRL_TYPE_INTEGER64: + v4l2Ctrls[i].value64 = ctrl->value(); + break; + default: + /* + * \todo To be changed when support for string and + * compound controls will be added. + */ + v4l2Ctrls[i].value = ctrl->value(); + break; + } + } + + struct v4l2_ext_controls v4l2ExtCtrls = {}; + v4l2ExtCtrls.which = V4L2_CTRL_WHICH_CUR_VAL; + v4l2ExtCtrls.controls = v4l2Ctrls; + v4l2ExtCtrls.count = count; + + int ret = ioctl(VIDIOC_S_EXT_CTRLS, &v4l2ExtCtrls); + if (ret) { + unsigned int errorIdx = v4l2ExtCtrls.error_idx; + + /* Generic validation error. */ + if (errorIdx == 0 || errorIdx >= count) { + LOG(V4L2, Error) << "Unable to read controls: " + << strerror(ret); + return -EINVAL; + } + + /* A specific control failed. */ + LOG(V4L2, Error) << "Unable to read control " << errorIdx + << ": " << strerror(ret); + count = errorIdx - 1; + ret = errorIdx; + } + + updateControls(ctrls, controlInfo, v4l2Ctrls, count); + + return ret; +} + +/** * \brief Perform an IOCTL system call on the device node * \param[in] request The IOCTL request code * \param[in] argp A pointer to the IOCTL argument @@ -194,4 +351,37 @@ void V4L2Device::listControls() } } +/* + * \brief Update the value of the first \a count V4L2 controls in \a ctrls using + * values in \a v4l2Ctrls + * \param[inout] ctrls List of V4L2 controls to update + * \param[in] controlInfo List of V4L2 control information + * \param[in] v4l2Ctrls List of V4L2 extended controls as returned by the driver + * \param[in] count The number of controls to update + */ +void V4L2Device::updateControls(V4L2ControlList *ctrls, + const V4L2ControlInfo **controlInfo, + const struct v4l2_ext_control *v4l2Ctrls, + unsigned int count) +{ + for (unsigned int i = 0; i < count; ++i) { + const struct v4l2_ext_control *v4l2Ctrl = &v4l2Ctrls[i]; + const V4L2ControlInfo *info = controlInfo[i]; + V4L2Control *ctrl = ctrls->getByIndex(i); + + switch (info->type()) { + case V4L2_CTRL_TYPE_INTEGER64: + ctrl->setValue(v4l2Ctrl->value64); + break; + default: + /* + * \todo To be changed when support for string and + * compound controls will be added. + */ + ctrl->setValue(v4l2Ctrl->value); + break; + } + } +} + } /* namespace libcamera */ |