ipa: rpi: Defer initialising AF LensPosition ControlInfo and value

This fixes two small bugs:

We previously populated LensPosition's ControlInfo with hard-coded
values, ignoring the tuning file. Now we query the AfAlgorithm to
get limits (over all AF ranges) and default (for AfRangeNormal).

We previously sent a default position to the lens driver, even when
a user-specified starting position would follow. Defer doing this,
to reduce unnecessary lens movement at startup (for some drivers).

Bug: https://bugs.libcamera.org/show_bug.cgi?id=258
Signed-off-by: Nick Hollinghurst <nick.hollinghurst@raspberrypi.com>
Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/ipa/rpi/controller/af_algorithm.h

@@ -33,6 +33,10 @@ public:
 	 *
 	 * getMode() is provided mainly for validating controls.
 	 * getLensPosition() is provided for populating DeviceStatus.
+	 *
+	 * getDefaultlensPosition() and getLensLimits() were added for
+	 * populating ControlInfoMap. They return the static API limits
+	 * which should be independent of the current range or mode.
 	 */
 
 	enum AfRange { AfRangeNormal = 0,
@@ -66,7 +70,9 @@ public:
 	}
 	virtual void setMode(AfMode mode) = 0;
 	virtual AfMode getMode() const = 0;
-	virtual bool setLensPosition(double dioptres, int32_t *hwpos) = 0;
+	virtual double getDefaultLensPosition() const = 0;
+	virtual void getLensLimits(double &min, double &max) const = 0;
+	virtual bool setLensPosition(double dioptres, int32_t *hwpos, bool force = false) = 0;
 	virtual std::optional<double> getLensPosition() const = 0;
 	virtual void triggerScan() = 0;
 	virtual void cancelScan() = 0;

src/ipa/rpi/controller/rpi/af.cpp

@@ -715,11 +715,23 @@ void Af::setWindows(libcamera::Span<libcamera::Rectangle const> const &wins)
 		invalidateWeights();
 }
 
-bool Af::setLensPosition(double dioptres, int *hwpos)
+double Af::getDefaultLensPosition() const
+{
+	return cfg_.ranges[AfRangeNormal].focusDefault;
+}
+
+void Af::getLensLimits(double &min, double &max) const
+{
+	/* Limits for manual focus are set by map, not by ranges */
+	min = cfg_.map.domain().start;
+	max = cfg_.map.domain().end;
+}
+
+bool Af::setLensPosition(double dioptres, int *hwpos, bool force)
 {
 	bool changed = false;
 
-	if (mode_ == AfModeManual) {
+	if (mode_ == AfModeManual || force) {
 		LOG(RPiAf, Debug) << "setLensPosition: " << dioptres;
 		ftarget_ = cfg_.map.domain().clamp(dioptres);
 		changed = !(initted_ && fsmooth_ == ftarget_);

src/ipa/rpi/controller/rpi/af.h

@@ -54,7 +54,9 @@ public:
 	void setWindows(libcamera::Span<libcamera::Rectangle const> const &wins) override;
 	void setMode(AfMode mode) override;
 	AfMode getMode() const override;
-	bool setLensPosition(double dioptres, int32_t *hwpos) override;
+	double getDefaultLensPosition() const override;
+	void getLensLimits(double &min, double &max) const override;
+	bool setLensPosition(double dioptres, int32_t *hwpos, bool force) override;
 	std::optional<double> getLensPosition() const override;
 	void triggerScan() override;
 	void cancelScan() override;