[libcamera-devel,v3,1/2] libcamera: controls: Add read-only flag to ControlInfo
diff mbox series

Message ID 20231102172439.3543870-2-kieran.bingham@ideasonboard.com
State New
Headers show
Series
  • Add read-only flag to ControlInfo
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Commit Message

Kieran Bingham Nov. 2, 2023, 5:24 p.m. UTC 
From: Naushir Patuck <naush@raspberrypi.com>

Add a read-only flag to the ControlInfo flag to indicate whether a V4L2 control
is read-only or not. This flag only makes sense for V2L2 controls at preset, so
only update the ControlInfo constructor signature used by the V4L2Device class
to set the value of the flag.

Add a ControlInfo::readOnly() member function to retrive this flag.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
---
v2:
 - Initialised readOnly_ for ControlInfo(Span<>)
 - Improved documentation


 include/libcamera/controls.h  |  5 ++++-
 src/libcamera/controls.cpp    | 22 ++++++++++++++++++----
 src/libcamera/v4l2_device.cpp | 12 ++++++++----
 3 files changed, 30 insertions(+), 9 deletions(-)

Patch
diff mbox series 

diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
index cf94205577a5..488663a7ba04 100644
--- a/include/libcamera/controls.h
+++ b/include/libcamera/controls.h
@@ -270,7 +270,8 @@  class ControlInfo
 public:
 	explicit ControlInfo(const ControlValue &min = {},
 			     const ControlValue &max = {},
-			     const ControlValue &def = {});
+			     const ControlValue &def = {},
+			     bool readOnly = false);
 	explicit ControlInfo(Span<const ControlValue> values,
 			     const ControlValue &def = {});
 	explicit ControlInfo(std::set<bool> values, bool def);
@@ -279,6 +280,7 @@  public:
 	const ControlValue &min() const { return min_; }
 	const ControlValue &max() const { return max_; }
 	const ControlValue &def() const { return def_; }
+	bool readOnly() const { return readOnly_; }
 	const std::vector<ControlValue> &values() const { return values_; }
 
 	std::string toString() const;
@@ -297,6 +299,7 @@  private:
 	ControlValue min_;
 	ControlValue max_;
 	ControlValue def_;
+	bool readOnly_;
 	std::vector<ControlValue> values_;
 };
 
diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index b808116c01e5..8af304bdeac9 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -484,11 +484,13 @@  void ControlValue::reserve(ControlType type, bool isArray, std::size_t numElemen
  * \param[in] min The control minimum value
  * \param[in] max The control maximum value
  * \param[in] def The control default value
+ * \param[in] readOnly True if the control reports a dynamic property
  */
 ControlInfo::ControlInfo(const ControlValue &min,
 			 const ControlValue &max,
-			 const ControlValue &def)
-	: min_(min), max_(max), def_(def)
+			 const ControlValue &def,
+			 bool readOnly)
+	: min_(min), max_(max), def_(def), readOnly_(readOnly)
 {
 }
 
@@ -508,6 +510,7 @@  ControlInfo::ControlInfo(Span<const ControlValue> values,
 	min_ = values.front();
 	max_ = values.back();
 	def_ = !def.isNone() ? def : values.front();
+	readOnly_ = false;
 
 	values_.reserve(values.size());
 	for (const ControlValue &value : values)
@@ -525,7 +528,8 @@  ControlInfo::ControlInfo(Span<const ControlValue> values,
  * default value is \a def.
  */
 ControlInfo::ControlInfo(std::set<bool> values, bool def)
-	: min_(false), max_(true), def_(def), values_({ false, true })
+	: min_(false), max_(true), def_(def), readOnly_(false),
+	  values_({ false, true })
 {
 	ASSERT(values.count(def) && values.size() == 2);
 }
@@ -538,7 +542,7 @@  ControlInfo::ControlInfo(std::set<bool> values, bool def)
  * value. The minimum, maximum, and default values will all be \a value.
  */
 ControlInfo::ControlInfo(bool value)
-	: min_(value), max_(value), def_(value)
+	: min_(value), max_(value), def_(value), readOnly_(true)
 {
 	values_ = { value };
 }
@@ -571,6 +575,16 @@  ControlInfo::ControlInfo(bool value)
  * \return A ControlValue with the default value for the control
  */
 
+/**
+ * \fn ControlInfo::readOnly()
+ * \brief Identifies if a control is flagged as read-only
+ * \return True if the control is read-only, false otherwise
+ *
+ * Read-only controls may signify that the control is a volatile property and
+ * can not be set. Adding a read-only control to a control list may cause the
+ * list to fail when the list is submitted.
+ */
+
 /**
  * \fn ControlInfo::values()
  * \brief Retrieve the list of valid values
diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
index 24d208ef77dc..8563bbd2595f 100644
--- a/src/libcamera/v4l2_device.cpp
+++ b/src/libcamera/v4l2_device.cpp
@@ -536,17 +536,20 @@  std::optional<ControlInfo> V4L2Device::v4l2ControlInfo(const v4l2_query_ext_ctrl
 	case V4L2_CTRL_TYPE_U8:
 		return ControlInfo(static_cast<uint8_t>(ctrl.minimum),
 				   static_cast<uint8_t>(ctrl.maximum),
-				   static_cast<uint8_t>(ctrl.default_value));
+				   static_cast<uint8_t>(ctrl.default_value),
+				   !!(ctrl.flags & V4L2_CTRL_FLAG_READ_ONLY));
 
 	case V4L2_CTRL_TYPE_BOOLEAN:
 		return ControlInfo(static_cast<bool>(ctrl.minimum),
 				   static_cast<bool>(ctrl.maximum),
-				   static_cast<bool>(ctrl.default_value));
+				   static_cast<bool>(ctrl.default_value),
+				   !!(ctrl.flags & V4L2_CTRL_FLAG_READ_ONLY));
 
 	case V4L2_CTRL_TYPE_INTEGER64:
 		return ControlInfo(static_cast<int64_t>(ctrl.minimum),
 				   static_cast<int64_t>(ctrl.maximum),
-				   static_cast<int64_t>(ctrl.default_value));
+				   static_cast<int64_t>(ctrl.default_value),
+				   !!(ctrl.flags & V4L2_CTRL_FLAG_READ_ONLY));
 
 	case V4L2_CTRL_TYPE_INTEGER_MENU:
 	case V4L2_CTRL_TYPE_MENU:
@@ -555,7 +558,8 @@  std::optional<ControlInfo> V4L2Device::v4l2ControlInfo(const v4l2_query_ext_ctrl
 	default:
 		return ControlInfo(static_cast<int32_t>(ctrl.minimum),
 				   static_cast<int32_t>(ctrl.maximum),
-				   static_cast<int32_t>(ctrl.default_value));
+				   static_cast<int32_t>(ctrl.default_value),
+				   !!(ctrl.flags & V4L2_CTRL_FLAG_READ_ONLY));
 	}
 }