[libcamera-devel] [PATCH 2/2] libcamera: v4l2_device: Simplify usage of getControls()
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Sun Apr 26 01:16:23 CEST 2020
The V4L2Device::getControls() function takes a ControlList that needs to
be pre-populated with dummy entries for the controls that need to be
read. This is a cumbersome API, especially when reading a single
control. Make it nicer by passing the list of V4L2 controls as a vector
of control IDs, and returning a ControlList.
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
src/libcamera/camera_sensor.cpp | 23 ++++++---------
src/libcamera/include/camera_sensor.h | 2 +-
src/libcamera/include/v4l2_device.h | 2 +-
src/libcamera/v4l2_device.cpp | 42 ++++++++++++---------------
test/v4l2_videodevice/controls.cpp | 20 +++++++------
5 files changed, 41 insertions(+), 48 deletions(-)
diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index 2219a4307436..ce585cab1a4f 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -299,30 +299,25 @@ const ControlInfoMap &CameraSensor::controls() const
/**
* \brief Read controls from the sensor
- * \param[inout] ctrls The list of controls to read
+ * \param[in] ids The list of control to read, specified by their ID
*
- * This method reads the value of all controls contained in \a ctrls, and stores
- * their values in the corresponding \a ctrls entry.
+ * This method reads the value of all controls contained in \a ids, and returns
+ * their values as a ControlList.
*
- * If any control in \a ctrls is not supported by the device, is disabled (i.e.
+ * If any control in \a ids 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.
+ * read and this method returns an empty control list.
*
- * 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.
+ * If an error occurs while reading the controls, an empty list is returned.
*
* \sa V4L2Device::getControls()
*
- * \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
+ * \return The control values in a ControlList
*/
-int CameraSensor::getControls(ControlList *ctrls)
+ControlList CameraSensor::getControls(const std::vector<uint32_t> &ids)
{
- return subdev_->getControls(ctrls);
+ return subdev_->getControls(ids);
}
/**
diff --git a/src/libcamera/include/camera_sensor.h b/src/libcamera/include/camera_sensor.h
index 99cff98128dc..5277f7f7fe87 100644
--- a/src/libcamera/include/camera_sensor.h
+++ b/src/libcamera/include/camera_sensor.h
@@ -43,7 +43,7 @@ public:
int setFormat(V4L2SubdeviceFormat *format);
const ControlInfoMap &controls() const;
- int getControls(ControlList *ctrls);
+ ControlList getControls(const std::vector<uint32_t> &ids);
int setControls(ControlList *ctrls);
const ControlList &properties() const { return properties_; }
diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h
index ce8edd98a01d..e604a40df4c9 100644
--- a/src/libcamera/include/v4l2_device.h
+++ b/src/libcamera/include/v4l2_device.h
@@ -26,7 +26,7 @@ public:
const ControlInfoMap &controls() const { return controls_; }
- int getControls(ControlList *ctrls);
+ ControlList getControls(const std::vector<uint32_t> &ids);
int setControls(ControlList *ctrls);
const std::string &deviceNode() const { return deviceNode_; }
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 03e305165096..989ed05c9692 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -147,46 +147,42 @@ void V4L2Device::close()
/**
* \brief Read controls from the device
- * \param[inout] ctrls The list of controls to read
+ * \param[in] ids The list of control to read, specified by their ID
*
- * This method reads the value of all controls contained in \a ctrls, and stores
- * their values in the corresponding \a ctrls entry.
+ * This method reads the value of all controls contained in \a ids, and returns
+ * their values as a ControlList.
*
- * If any control in \a ctrls is not supported by the device, is disabled (i.e.
+ * If any control in \a ids 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.
+ * read and this method returns an empty control list.
*
- * 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.
+ * If an error occurs while reading the controls, an empty list is returned.
*
- * \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
+ * \return The control values in a ControlList
*/
-int V4L2Device::getControls(ControlList *ctrls)
+ControlList V4L2Device::getControls(const std::vector<uint32_t> &ids)
{
- unsigned int count = ctrls->size();
+ unsigned int count = ids.size();
if (count == 0)
- return 0;
+ return {};
+
+ ControlList ctrls{ controls_ };
struct v4l2_ext_control v4l2Ctrls[count];
memset(v4l2Ctrls, 0, sizeof(v4l2Ctrls));
unsigned int i = 0;
- for (auto &ctrl : *ctrls) {
- unsigned int id = ctrl.first;
+ for (uint32_t id : ids) {
const auto iter = controls_.find(id);
if (iter == controls_.end()) {
LOG(V4L2, Error)
<< "Control " << utils::hex(id) << " not found";
- return -EINVAL;
+ return {};
}
const struct v4l2_query_ext_ctrl &info = controlInfo_[id];
- ControlValue &value = ctrl.second;
+ ControlValue &value = ctrls.set(id, {});
if (info.flags & V4L2_CTRL_FLAG_HAS_PAYLOAD) {
ControlType type;
@@ -200,7 +196,7 @@ int V4L2Device::getControls(ControlList *ctrls)
LOG(V4L2, Error)
<< "Unsupported payload control type "
<< info.type;
- return -EINVAL;
+ return {};
}
value.reserve(type, true, info.elems);
@@ -227,7 +223,7 @@ int V4L2Device::getControls(ControlList *ctrls)
if (errorIdx == 0 || errorIdx >= count) {
LOG(V4L2, Error) << "Unable to read controls: "
<< strerror(-ret);
- return -EINVAL;
+ return {};
}
/* A specific control failed. */
@@ -237,9 +233,9 @@ int V4L2Device::getControls(ControlList *ctrls)
ret = errorIdx;
}
- updateControls(ctrls, v4l2Ctrls, count);
+ updateControls(&ctrls, v4l2Ctrls, count);
- return ret;
+ return ctrls;
}
/**
diff --git a/test/v4l2_videodevice/controls.cpp b/test/v4l2_videodevice/controls.cpp
index da9e0111e221..347af2112f1a 100644
--- a/test/v4l2_videodevice/controls.cpp
+++ b/test/v4l2_videodevice/controls.cpp
@@ -57,18 +57,20 @@ protected:
const ControlInfo &u8 = infoMap.find(VIVID_CID_U8_4D_ARRAY)->second;
/* Test getting controls. */
- ControlList ctrls(infoMap);
- ctrls.set(V4L2_CID_BRIGHTNESS, -1);
- ctrls.set(V4L2_CID_CONTRAST, -1);
- ctrls.set(V4L2_CID_SATURATION, -1);
- ctrls.set(VIVID_CID_U8_4D_ARRAY, 0);
-
- int ret = capture_->getControls(&ctrls);
- if (ret) {
+ ControlList ctrls = capture_->getControls({ V4L2_CID_BRIGHTNESS,
+ V4L2_CID_CONTRAST,
+ V4L2_CID_SATURATION,
+ VIVID_CID_U8_4D_ARRAY });
+ if (ctrls.empty()) {
cerr << "Failed to get controls" << endl;
return TestFail;
}
+ if (ctrls.infoMap() != &infoMap) {
+ cerr << "Incorrect infoMap for retrieved controls" << endl;
+ return TestFail;
+ }
+
if (ctrls.get(V4L2_CID_BRIGHTNESS).get<int32_t>() == -1 ||
ctrls.get(V4L2_CID_CONTRAST).get<int32_t>() == -1 ||
ctrls.get(V4L2_CID_SATURATION).get<int32_t>() == -1) {
@@ -97,7 +99,7 @@ protected:
std::fill(u8Values.begin(), u8Values.end(), u8.min().get<uint8_t>());
ctrls.set(VIVID_CID_U8_4D_ARRAY, Span<const uint8_t>(u8Values));
- ret = capture_->setControls(&ctrls);
+ int ret = capture_->setControls(&ctrls);
if (ret) {
cerr << "Failed to set controls" << endl;
return TestFail;
--
Regards,
Laurent Pinchart
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