diff --git a/Documentation/sensor_driver_requirements.rst b/Documentation/sensor_driver_requirements.rst
index b0854be3328a..3abc8f35924a 100644
--- a/Documentation/sensor_driver_requirements.rst
+++ b/Documentation/sensor_driver_requirements.rst
@@ -24,16 +24,23 @@ The sensor driver is assumed to be fully compliant with the V4L2 specification.
 
 For RAW sensors, the sensor driver shall support the following V4L2 controls:
 
+* `V4L2_CID_ANALOGUE_GAIN`_
 * `V4L2_CID_EXPOSURE`_
 * `V4L2_CID_HBLANK`_
 * `V4L2_CID_PIXEL_RATE`_
 * `V4L2_CID_VBLANK`_
 
+.. _V4L2_CID_ANALOGUE_GAIN: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-source.html
 .. _V4L2_CID_EXPOSURE: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/control.html
 .. _V4L2_CID_HBLANK: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-source.html
 .. _V4L2_CID_PIXEL_RATE: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-process.html
 .. _V4L2_CID_VBLANK: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-source.html
 
+The ``ANALOGUE_GAIN`` control units are sensor-specific. libcamera requires
+a sensor-specific CameraSensorHelper implementation to translate between the
+sensor specific ``gain code`` and the analogue ``gain value`` expressed as an
+absolute number as defined by ``controls::AnalogueGain``.
+
 While V4L2 doesn't specify a unit for the ``EXPOSURE`` control, libcamera
 requires it to be expressed as a number of image lines. Camera sensor drivers
 that do not comply with this requirement will need to be adapted or will produce
diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
index a9a2b49ca95b..08ee6eb30cc5 100644
--- a/src/ipa/ipu3/ipu3.cpp
+++ b/src/ipa/ipu3/ipu3.cpp
@@ -171,8 +171,6 @@ private:
 			    ControlInfoMap *ipaControls);
 	void updateSessionConfiguration(const ControlInfoMap &sensorControls);
 
-	bool validateSensorControls();
-
 	void setControls(unsigned int frame);
 	void calculateBdsGrid(const Size &bdsOutputSize);
 
@@ -292,28 +290,6 @@ void IPAIPU3::updateControls(const IPACameraSensorInfo &sensorInfo,
 	*ipaControls = ControlInfoMap(std::move(controls), controls::controls);
 }
 
-/**
- * \brief Validate that the sensor controls mandatory for the IPA exists
- */
-bool IPAIPU3::validateSensorControls()
-{
-	static const uint32_t ctrls[] = {
-		V4L2_CID_ANALOGUE_GAIN,
-		V4L2_CID_EXPOSURE,
-		V4L2_CID_VBLANK,
-	};
-
-	for (auto c : ctrls) {
-		if (sensorCtrls_.find(c) == sensorCtrls_.end()) {
-			LOG(IPAIPU3, Error) << "Unable to find sensor control "
-					    << utils::hex(c);
-			return false;
-		}
-	}
-
-	return true;
-}
-
 /**
  * \brief Initialize the IPA module and its controls
  *
@@ -512,11 +488,6 @@ int IPAIPU3::configure(const IPAConfigInfo &configInfo,
 
 	calculateBdsGrid(configInfo.bdsOutputSize);
 
-	if (!validateSensorControls()) {
-		LOG(IPAIPU3, Error) << "Sensor control validation failed.";
-		return -EINVAL;
-	}
-
 	/* Update the camera controls using the new sensor settings. */
 	updateControls(sensorInfo_, sensorCtrls_, ipaControls);
 
diff --git a/src/ipa/rkisp1/rkisp1.cpp b/src/ipa/rkisp1/rkisp1.cpp
index fcb9dacccc3c..d237758f7bf0 100644
--- a/src/ipa/rkisp1/rkisp1.cpp
+++ b/src/ipa/rkisp1/rkisp1.cpp
@@ -216,20 +216,10 @@ int IPARkISP1::configure([[maybe_unused]] const IPACameraSensorInfo &info,
 	ctrls_ = entityControls.at(0);
 
 	const auto itExp = ctrls_.find(V4L2_CID_EXPOSURE);
-	if (itExp == ctrls_.end()) {
-		LOG(IPARkISP1, Error) << "Can't find exposure control";
-		return -EINVAL;
-	}
-
-	const auto itGain = ctrls_.find(V4L2_CID_ANALOGUE_GAIN);
-	if (itGain == ctrls_.end()) {
-		LOG(IPARkISP1, Error) << "Can't find gain control";
-		return -EINVAL;
-	}
-
 	int32_t minExposure = itExp->second.min().get<int32_t>();
 	int32_t maxExposure = itExp->second.max().get<int32_t>();
 
+	const auto itGain = ctrls_.find(V4L2_CID_ANALOGUE_GAIN);
 	int32_t minGain = itGain->second.min().get<int32_t>();
 	int32_t maxGain = itGain->second.max().get<int32_t>();
 
diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index 572a313a8f99..ea373458a164 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -301,6 +301,7 @@ int CameraSensor::validateSensorDriver()
 	 * required by the CameraSensor class.
 	 */
 	static constexpr uint32_t mandatoryControls[] = {
+		V4L2_CID_ANALOGUE_GAIN,
 		V4L2_CID_EXPOSURE,
 		V4L2_CID_HBLANK,
 		V4L2_CID_PIXEL_RATE,