pipeline: rpi: Add support for Raspberry Pi 5

Add the Raspberry Pi 5 ISP (PiSP) pipeline handler to libcamera. To
include this pipeline handler in the build, set the following meson
option:

meson configure -Dpipelines=rpi/pisp

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: David Plowman <david.plowman@raspberrypi.com>

8 files changed, 2292 insertions, 1 deletions

diff --git a/Documentation/guides/pipeline-handler.rst b/Documentation/guides/pipeline-handler.rst
index 10b9c75c..7ca22ef8 100644
--- a/Documentation/guides/pipeline-handler.rst
+++ b/Documentation/guides/pipeline-handler.rst
@@ -183,7 +183,7 @@ to the libcamera build options in the top level ``meson_options.txt``.
 
    option('pipelines',
            type : 'array',
-           choices : ['ipu3', 'rkisp1', 'rpi/vc4', 'simple', 'uvcvideo', 'vimc', 'vivid'],
+           choices : ['ipu3', 'rkisp1', 'rpi/pisp', 'rpi/vc4', 'simple', 'uvcvideo', 'vimc', 'vivid'],
            description : 'Select which pipeline handlers to include')
 
 
diff --git a/include/libcamera/ipa/meson.build b/include/libcamera/ipa/meson.build
index f3b4881c..c1d913f5 100644
--- a/include/libcamera/ipa/meson.build
+++ b/include/libcamera/ipa/meson.build
@@ -64,6 +64,7 @@ libcamera_generated_ipa_headers += custom_target('core_ipa_serializer_h',
 pipeline_ipa_mojom_mapping = {
     'ipu3': 'ipu3.mojom',
     'rkisp1': 'rkisp1.mojom',
+    'rpi/pisp': 'raspberrypi.mojom',
     'rpi/vc4': 'raspberrypi.mojom',
     'vimc': 'vimc.mojom',
 }
diff --git a/meson.build b/meson.build
index e9a1c7e3..a0c27edb 100644
--- a/meson.build
+++ b/meson.build
@@ -199,6 +199,7 @@ pipelines_support = {
     'imx8-isi':     arch_arm,
     'ipu3':         arch_x86,
     'rkisp1':       arch_arm,
+    'rpi/pisp':     arch_arm,
     'rpi/vc4':      arch_arm,
     'simple':       arch_arm,
     'uvcvideo':     ['any'],
diff --git a/meson_options.txt b/meson_options.txt
index fad928af..0426f7f0 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -44,6 +44,7 @@ option('pipelines',
             'imx8-isi',
             'ipu3',
             'rkisp1',
+            'rpi/pisp',
             'rpi/vc4',
             'simple',
             'uvcvideo',
diff --git a/src/libcamera/pipeline/rpi/pisp/data/example.yaml b/src/libcamera/pipeline/rpi/pisp/data/example.yaml
new file mode 100644
index 00000000..7b8e51f7
--- /dev/null
+++ b/src/libcamera/pipeline/rpi/pisp/data/example.yaml
@@ -0,0 +1,45 @@
+{
+        "version": 1.0,
+        "target": "pisp",
+
+        "pipeline_handler":
+        {
+                # Number of CFE config and stats buffers to allocate and use. A
+                # larger number minimises the possibility of dropping frames,
+                # but increases the latency for updating the HW configuration.
+                #
+                # "num_cfe_config_stats_buffers": 12,
+
+		# Number of jobs to queue ahead to the CFE on startup. A larger
+                # number will increase latency for 3A changes, but may reduce 
+                # avoidable frame drops.
+                #
+                # "num_cfe_config_queue": 2,
+
+                # Override any request from the IPA to drop a number of startup
+                # frames.
+                #
+                # "disable_startup_frame_drops": false,
+
+                # Custom timeout value (in ms) for camera to use. This overrides
+                # the value computed by the pipeline handler based on frame
+                # durations.
+                #
+                # Set this value to 0 to use the pipeline handler computed
+                # timeout value.
+                #
+                # "camera_timeout_value_ms": 0,
+
+                # Disables temporal denoise functionality in the ISP pipeline.
+                # Disabling temporal denoise avoids allocating 2 additional
+                # Bayer framebuffers required for its operation.
+                #
+                # "disable_tdn": false,
+
+                # Disables multiframe HDR functionality in the ISP pipeline.
+                # Disabling multiframe HDR avoids allocating 2 additional Bayer
+                # framebuffers required for its operation.
+                #
+                # "disable_hdr": false,
+        }
+}
diff --git a/src/libcamera/pipeline/rpi/pisp/data/meson.build b/src/libcamera/pipeline/rpi/pisp/data/meson.build
new file mode 100644
index 00000000..17dfc435
--- /dev/null
+++ b/src/libcamera/pipeline/rpi/pisp/data/meson.build
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: CC0-1.0
+
+conf_files = files([
+    'example.yaml',
+])
+
+install_data(conf_files,
+             install_dir : pipeline_data_dir / 'rpi' / 'pisp')
diff --git a/src/libcamera/pipeline/rpi/pisp/meson.build b/src/libcamera/pipeline/rpi/pisp/meson.build
new file mode 100644
index 00000000..1f0ca3ca
--- /dev/null
+++ b/src/libcamera/pipeline/rpi/pisp/meson.build
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: CC0-1.0
+
+libcamera_sources += files([
+    'pisp.cpp',
+])
+
+librt = cc.find_library('rt', required : true)
+libpisp_dep = dependency('libpisp', fallback : ['libpisp', 'libpisp_dep'])
+
+libcamera_deps += [libpisp_dep, librt]
+
+subdir('data')
diff --git a/src/libcamera/pipeline/rpi/pisp/pisp.cpp b/src/libcamera/pipeline/rpi/pisp/pisp.cpp
new file mode 100644
index 00000000..a977ed01
--- /dev/null
+++ b/src/libcamera/pipeline/rpi/pisp/pisp.cpp
@@ -0,0 +1,2223 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2023, Raspberry Pi Ltd
+ *
+ * pisp.cpp - Pipeline handler for PiSP based Raspberry Pi devices
+ */
+
+#include <algorithm>
+#include <fstream>
+#include <memory>
+#include <mutex>
+#include <numeric>
+#include <queue>
+#include <set>
+#include <sstream>
+#include <string>
+#include <sys/ioctl.h>
+#include <unordered_map>
+#include <vector>
+
+#include <linux/dma-buf.h>
+#include <linux/v4l2-controls.h>
+#include <linux/videodev2.h>
+
+#include <libcamera/base/shared_fd.h>
+#include <libcamera/formats.h>
+
+#include "libcamera/internal/device_enumerator.h"
+
+#include "libpisp/backend/backend.hpp"
+#include "libpisp/common/logging.hpp"
+#include "libpisp/common/utils.hpp"
+#include "libpisp/common/version.hpp"
+#include "libpisp/frontend/frontend.hpp"
+#include "libpisp/variants/variant.hpp"
+
+#include "../common/pipeline_base.h"
+#include "../common/rpi_stream.h"
+#include "../common/shared_mem_object.h"
+
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(RPI)
+
+using StreamFlag = RPi::Stream::StreamFlag;
+using StreamParams = RPi::RPiCameraConfiguration::StreamParams;
+
+namespace {
+
+enum class Cfe : unsigned int { Output0, Embedded, Stats, Config };
+enum class Isp : unsigned int { Input, Output0, Output1, TdnInput, TdnOutput,
+				StitchInput, StitchOutput, Config };
+
+/* Offset for all compressed buffers; mode for TDN and Stitch. */
+constexpr unsigned int DefaultCompressionOffset = 2048;
+constexpr unsigned int DefaultCompressionMode = 1;
+
+const std::vector<std::pair<BayerFormat, unsigned int>> BayerToMbusCodeMap{
+	{ { BayerFormat::BGGR, 8, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SBGGR8_1X8, },
+	{ { BayerFormat::GBRG, 8, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGBRG8_1X8, },
+	{ { BayerFormat::GRBG, 8, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGRBG8_1X8, },
+	{ { BayerFormat::RGGB, 8, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SRGGB8_1X8, },
+	{ { BayerFormat::BGGR, 10, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SBGGR10_1X10, },
+	{ { BayerFormat::GBRG, 10, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGBRG10_1X10, },
+	{ { BayerFormat::GRBG, 10, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGRBG10_1X10, },
+	{ { BayerFormat::RGGB, 10, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SRGGB10_1X10, },
+	{ { BayerFormat::BGGR, 12, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SBGGR12_1X12, },
+	{ { BayerFormat::GBRG, 12, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGBRG12_1X12, },
+	{ { BayerFormat::GRBG, 12, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGRBG12_1X12, },
+	{ { BayerFormat::RGGB, 12, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SRGGB12_1X12, },
+	{ { BayerFormat::BGGR, 14, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SBGGR14_1X14, },
+	{ { BayerFormat::GBRG, 14, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGBRG14_1X14, },
+	{ { BayerFormat::GRBG, 14, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGRBG14_1X14, },
+	{ { BayerFormat::RGGB, 14, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SRGGB14_1X14, },
+	{ { BayerFormat::BGGR, 16, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SBGGR16_1X16, },
+	{ { BayerFormat::GBRG, 16, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGBRG16_1X16, },
+	{ { BayerFormat::GRBG, 16, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SGRBG16_1X16, },
+	{ { BayerFormat::RGGB, 16, BayerFormat::Packing::None }, MEDIA_BUS_FMT_SRGGB16_1X16, },
+	{ { BayerFormat::BGGR, 16, BayerFormat::Packing::PISP1 }, MEDIA_BUS_FMT_SBGGR16_1X16, },
+	{ { BayerFormat::GBRG, 16, BayerFormat::Packing::PISP1 }, MEDIA_BUS_FMT_SGBRG16_1X16, },
+	{ { BayerFormat::GRBG, 16, BayerFormat::Packing::PISP1 }, MEDIA_BUS_FMT_SGRBG16_1X16, },
+	{ { BayerFormat::RGGB, 16, BayerFormat::Packing::PISP1 }, MEDIA_BUS_FMT_SRGGB16_1X16, },
+};
+
+unsigned int bayerToMbusCode(const BayerFormat &bayer)
+{
+	const auto it = std::find_if(BayerToMbusCodeMap.begin(), BayerToMbusCodeMap.end(),
+				     [bayer](const std::pair<BayerFormat, unsigned int> &match) {
+						return bayer == match.first;
+				     });
+
+	if (it != BayerToMbusCodeMap.end())
+		return it->second;
+
+	return 0;
+}
+
+uint32_t mbusCodeUnpacked16(unsigned int mbus_code)
+{
+	BayerFormat bayer = BayerFormat::fromMbusCode(mbus_code);
+	BayerFormat bayer16(bayer.order, 16, BayerFormat::Packing::None);
+
+	return bayerToMbusCode(bayer16);
+}
+
+uint8_t toPiSPBayerOrder(V4L2PixelFormat format)
+{
+	BayerFormat bayer = BayerFormat::fromV4L2PixelFormat(format);
+
+	switch (bayer.order) {
+	case BayerFormat::Order::BGGR:
+		return PISP_BAYER_ORDER_BGGR;
+	case BayerFormat::Order::GBRG:
+		return PISP_BAYER_ORDER_GBRG;
+	case BayerFormat::Order::GRBG:
+		return PISP_BAYER_ORDER_GRBG;
+	case BayerFormat::Order::RGGB:
+		return PISP_BAYER_ORDER_RGGB;
+	default:
+		ASSERT(0);
+		return -1;
+	}
+}
+
+pisp_image_format_config toPiSPImageFormat(V4L2DeviceFormat &format)
+{
+	pisp_image_format_config image = {};
+
+	image.width = format.size.width;
+	image.height = format.size.height;
+	image.stride = format.planes[0].bpl;
+
+	PixelFormat pix = format.fourcc.toPixelFormat();
+
+	if (RPi::PipelineHandlerBase::isRaw(pix)) {
+		BayerFormat bayer = BayerFormat::fromPixelFormat(pix);
+		switch (bayer.packing) {
+		case BayerFormat::Packing::None:
+			image.format = PISP_IMAGE_FORMAT_BPS_16 +
+				       PISP_IMAGE_FORMAT_UNCOMPRESSED;
+			break;
+		case BayerFormat::Packing::PISP1:
+			image.format = PISP_IMAGE_FORMAT_COMPRESSION_MODE_1;
+			break;
+		case BayerFormat::Packing::PISP2:
+			image.format = PISP_IMAGE_FORMAT_COMPRESSION_MODE_2;
+			break;
+		default:
+			ASSERT(0);
+		}
+		return image;
+	}
+
+	switch (pix) {
+	case formats::YUV420:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL +
+			       PISP_IMAGE_FORMAT_BPS_8 +
+			       PISP_IMAGE_FORMAT_SAMPLING_420 +
+			       PISP_IMAGE_FORMAT_PLANARITY_PLANAR;
+		image.stride2 = image.stride / 2;
+		break;
+	case formats::NV12:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL +
+			       PISP_IMAGE_FORMAT_BPS_8 +
+			       PISP_IMAGE_FORMAT_SAMPLING_420 +
+			       PISP_IMAGE_FORMAT_PLANARITY_SEMI_PLANAR;
+		image.stride2 = image.stride;
+		break;
+	case formats::NV21:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL +
+			       PISP_IMAGE_FORMAT_BPS_8 +
+			       PISP_IMAGE_FORMAT_SAMPLING_420 +
+			       PISP_IMAGE_FORMAT_PLANARITY_SEMI_PLANAR +
+			       PISP_IMAGE_FORMAT_ORDER_SWAPPED;
+		image.stride2 = image.stride;
+		break;
+	case formats::YUYV:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL +
+			       PISP_IMAGE_FORMAT_BPS_8 +
+			       PISP_IMAGE_FORMAT_SAMPLING_422 +
+			       PISP_IMAGE_FORMAT_PLANARITY_INTERLEAVED;
+		break;
+	case formats::UYVY:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL +
+			       PISP_IMAGE_FORMAT_BPS_8 +
+			       PISP_IMAGE_FORMAT_SAMPLING_422 +
+			       PISP_IMAGE_FORMAT_PLANARITY_INTERLEAVED +
+			       PISP_IMAGE_FORMAT_ORDER_SWAPPED;
+		break;
+	case formats::NV16:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL +
+			       PISP_IMAGE_FORMAT_BPS_8 +
+			       PISP_IMAGE_FORMAT_SAMPLING_422 +
+			       PISP_IMAGE_FORMAT_PLANARITY_SEMI_PLANAR;
+		image.stride2 = image.stride;
+		break;
+	case formats::NV61:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL +
+			       PISP_IMAGE_FORMAT_BPS_8 +
+			       PISP_IMAGE_FORMAT_SAMPLING_422 +
+			       PISP_IMAGE_FORMAT_PLANARITY_SEMI_PLANAR +
+			       PISP_IMAGE_FORMAT_ORDER_SWAPPED;
+		image.stride2 = image.stride;
+		break;
+	case formats::RGB888:
+	case formats::BGR888:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL;
+		break;
+	case formats::XRGB8888:
+	case formats::XBGR8888:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL + PISP_IMAGE_FORMAT_BPP_32;
+		break;
+	case formats::RGBX8888:
+	case formats::BGRX8888:
+		image.format = PISP_IMAGE_FORMAT_THREE_CHANNEL + PISP_IMAGE_FORMAT_BPP_32 +
+			       PISP_IMAGE_FORMAT_ORDER_SWAPPED;
+		break;
+	default:
+		LOG(RPI, Error) << "Pixel format " << pix << " unsupported";
+		ASSERT(0);
+	}
+
+	return image;
+}
+
+void computeOptimalStride(V4L2DeviceFormat &format)
+{
+	pisp_image_format_config fmt = toPiSPImageFormat(format);
+
+	libpisp::compute_optimal_stride(fmt);
+
+	uint32_t fourcc = format.fourcc.fourcc();
+
+	/*
+	 * For YUV420/422 non-multiplanar formats, double the U/V stride for the
+	 * Y-plane to ensure we get the optimal alignment on all three planes.
+	 */
+	if (fourcc == V4L2_PIX_FMT_YUV420 || fourcc == V4L2_PIX_FMT_YUV422P ||
+	    fourcc == V4L2_PIX_FMT_YVU420)
+		fmt.stride = fmt.stride2 * 2;
+
+	format.planes[0].bpl = fmt.stride;
+	format.planes[1].bpl = fmt.stride2;
+	format.planes[2].bpl = fmt.stride2;
+
+	/*
+	 * Need to set planesCount correctly so that V4L2VideoDevice::trySetFormatMultiplane()
+	 * copies the bpl fields correctly.
+	 */
+	const PixelFormat &pixFormat = format.fourcc.toPixelFormat();
+	const PixelFormatInfo &info = PixelFormatInfo::info(pixFormat);
+	format.planesCount = info.numPlanes();
+}
+
+void setupOutputClipping(const V4L2DeviceFormat &v4l2Format,
+			 pisp_be_output_format_config &outputFormat)
+{
+	const PixelFormat &pixFormat = v4l2Format.fourcc.toPixelFormat();
+	const PixelFormatInfo &info = PixelFormatInfo::info(pixFormat);
+
+	if (info.colourEncoding != PixelFormatInfo::ColourEncodingYUV)
+		return;
+
+	if (v4l2Format.colorSpace == ColorSpace::Sycc) {
+		outputFormat.lo = 0;
+		outputFormat.hi = 65535;
+		outputFormat.lo2 = 0;
+		outputFormat.hi2 = 65535;
+	} else if (v4l2Format.colorSpace == ColorSpace::Smpte170m ||
+			v4l2Format.colorSpace == ColorSpace::Rec709) {
+		outputFormat.lo = 16 << 8;
+		outputFormat.hi = 235 << 8;
+		outputFormat.lo2 = 16 << 8;
+		outputFormat.hi2 = 240 << 8;
+	} else {
+		LOG(RPI, Warning)
+			<< "Unrecognised colour space "
+			<< ColorSpace::toString(v4l2Format.colorSpace)
+			<< ", using full range";
+		outputFormat.lo = 0;
+		outputFormat.hi = 65535;
+		outputFormat.lo2 = 0;
+		outputFormat.hi2 = 65535;
+	}
+}
+
+int dmabufSyncStart(const SharedFD &fd)
+{
+	struct dma_buf_sync dma_sync {};
+	dma_sync.flags = DMA_BUF_SYNC_START | DMA_BUF_SYNC_RW;
+
+	int ret = ::ioctl(fd.get(), DMA_BUF_IOCTL_SYNC, &dma_sync);
+	if (ret)
+		LOG(RPI, Error) << "failed to lock-sync-write dma buf";
+
+	return ret;
+}
+
+int dmabufSyncEnd(const SharedFD &fd)
+{
+	struct dma_buf_sync dma_sync {};
+	dma_sync.flags = DMA_BUF_SYNC_END | DMA_BUF_SYNC_RW;
+
+	int ret = ::ioctl(fd.get(), DMA_BUF_IOCTL_SYNC, &dma_sync);
+
+	if (ret)
+		LOG(RPI, Error) << "failed to unlock-sync-write dma buf";
+
+	return ret;
+}
+
+void do32BitConversion(void *mem, unsigned int width, unsigned int height,
+		       unsigned int stride)
+{
+	/*
+	 * The arm64 version is actually not that much quicker because the
+	 * vast bulk of the time is spent waiting for memory.
+	 */
+#if __aarch64__
+	for (unsigned int j = 0; j < height; j++) {
+		uint8_t *ptr = (uint8_t *)mem + j * stride;
+		unsigned int count = (width + 15) / 16;
+		uint8_t *dest = ptr + count * 64;
+		uint8_t *src = ptr + count * 48;
+
+		/* Pre-decrement would have been nice. */
+		asm volatile("movi v3.16b, #255 \n"
+				"1: \n"
+				"sub %[src], %[src], #48 \n"
+				"sub %[dest], %[dest], #64 \n"
+				"subs %[count], %[count], #1 \n"
+				"ld3 {v0.16b, v1.16b, v2.16b}, [%[src]] \n"
+				"st4 {v0.16b, v1.16b, v2.16b, v3.16b}, [%[dest]] \n"
+				"b.gt 1b \n"
+				: [count]"+r" (count)
+				: [src]"r" (src), [dest]"r" (dest)
+				: "cc", "v1", "v2", "v3", "v4", "memory"
+				);
+	}
+#else
+	std::vector<uint8_t> incache(3 * width);
+	std::vector<uint8_t> outcache(4 * width);
+
+	memcpy(incache.data(), mem, 3 * width);
+	for (unsigned int j = 0; j < height; j++) {
+		uint8_t *ptr = (uint8_t *)mem + j * stride;
+
+		uint8_t *ptr3 = incache.data();
+		uint8_t *ptr4 = outcache.data();
+		for (unsigned int i = 0; i < width; i++) {
+			*(ptr4++) = *(ptr3++);
+			*(ptr4++) = *(ptr3++);
+			*(ptr4++) = *(ptr3++);
+			*(ptr4++) = 255;
+		}
+
+		if (j < height - 1)
+			memcpy(incache.data(), ptr + stride, 3 * width);
+		memcpy(ptr, outcache.data(), 4 * width);
+	}
+#endif
+}
+
+void downscaleInterleaved3(void *mem, unsigned int height, unsigned int src_width,
+			   unsigned int stride)
+{
+	std::vector<uint8_t> incache(3 * src_width);
+	unsigned int dst_width = src_width / 2;
+	std::vector<uint8_t> outcache(3 * dst_width);
+
+	memcpy(incache.data(), mem, 3 * src_width);
+	for (unsigned int j = 0; j < height; j++) {
+		uint8_t *ptr = (uint8_t *)mem + j * stride;
+
+		uint8_t *src = incache.data(), *dst = outcache.data();
+		for (unsigned int i = 0; i < dst_width; i++, src += 6, dst += 3) {
+			dst[0] = ((int)src[0] + (int)src[3] + 1) >> 1;
+			dst[1] = ((int)src[1] + (int)src[4] + 1) >> 1;
+			dst[2] = ((int)src[2] + (int)src[5] + 1) >> 1;
+		}
+
+		if (j < height - 1)
+			memcpy(incache.data(), ptr + stride, 3 * src_width);
+		memcpy(ptr, outcache.data(), 3 * dst_width);
+	}
+}
+
+void downscaleInterleaved4(void *mem, unsigned int height, unsigned int src_width,
+			   unsigned int stride)
+{
+	std::vector<uint8_t> incache(4 * src_width);
+	unsigned int dst_width = src_width / 2;
+	std::vector<uint8_t> outcache(4 * dst_width);
+
+	memcpy(incache.data(), mem, 4 * src_width);
+	for (unsigned int j = 0; j < height; j++) {
+		uint8_t *ptr = (uint8_t *)mem + j * stride;
+
+		uint8_t *src = incache.data(), *dst = outcache.data();
+		for (unsigned int i = 0; i < dst_width; i++, src += 8, dst += 4) {
+			dst[0] = ((int)src[0] + (int)src[4] + 1) >> 1;
+			dst[1] = ((int)src[1] + (int)src[5] + 1) >> 1;
+			dst[2] = ((int)src[2] + (int)src[6] + 1) >> 1;
+			dst[3] = ((int)src[3] + (int)src[7] + 1) >> 1;
+		}
+
+		if (j < height - 1)
+			memcpy(incache.data(), ptr + stride, 4 * src_width);
+		memcpy(ptr, outcache.data(), 4 * dst_width);
+	}
+}
+
+void downscalePlaneInternal(void *mem, unsigned int height, unsigned int src_width,
+			    unsigned int stride, std::vector<uint8_t> &incache,
+			    std::vector<uint8_t> &outcache)
+{
+	unsigned int dst_width = src_width / 2;
+	memcpy(incache.data(), mem, src_width);
+	for (unsigned int j = 0; j < height; j++) {
+		uint8_t *ptr = (uint8_t *)mem + j * stride;
+
+		uint8_t *src = incache.data(), *dst = outcache.data();
+		for (unsigned int i = 0; i < dst_width; i++, src += 2, dst++)
+			*dst = ((int)src[0] + (int)src[1] + 1) >> 1;
+
+		if (j < height - 1)
+			memcpy(incache.data(), ptr + stride, src_width);
+		memcpy(ptr, outcache.data(), dst_width);
+	}
+}
+
+void downscalePlanar420(void *memY, void *memU, void *memV, unsigned int height,
+			unsigned int src_width, unsigned int stride)
+{
+	std::vector<uint8_t> incache(src_width);
+	std::vector<uint8_t> outcache(src_width / 2);
+
+	downscalePlaneInternal(memY, height, src_width, stride, incache, outcache);
+	downscalePlaneInternal(memU, height / 2, src_width / 2, stride / 2, incache, outcache);
+	downscalePlaneInternal(memV, height / 2, src_width / 2, stride / 2, incache, outcache);
+}
+
+void downscalePlanar422(void *memY, void *memU, void *memV,
+			unsigned int height, unsigned int src_width, unsigned int stride)
+{
+	std::vector<uint8_t> incache(src_width);
+	std::vector<uint8_t> outcache(src_width / 2);
+
+	downscalePlaneInternal(memY, height, src_width, stride, incache, outcache);
+	downscalePlaneInternal(memU, height, src_width / 2, stride / 2, incache, outcache);
+	downscalePlaneInternal(memV, height, src_width / 2, stride / 2, incache, outcache);
+}
+
+void downscaleInterleavedYuyv(void *mem, unsigned int height, unsigned int src_width,
+			      unsigned int stride)
+{
+	std::vector<uint8_t> incache(2 * src_width);
+	unsigned int dst_width = src_width / 2;
+	std::vector<uint8_t> outcache(2 * dst_width);
+
+	memcpy(incache.data(), mem, 2 * src_width);
+	for (unsigned int j = 0; j < height; j++) {
+		uint8_t *ptr = (uint8_t *)mem + j * stride;
+
+		uint8_t *src = incache.data(), *dst = outcache.data();
+		for (unsigned int i = 0; i < dst_width; i++, src += 8, dst += 4) {
+			dst[0] = ((int)src[0] + (int)src[2] + 1) >> 1;
+			dst[1] = ((int)src[1] + (int)src[5] + 1) >> 1;
+			dst[2] = ((int)src[4] + (int)src[6] + 1) >> 1;
+			dst[3] = ((int)src[3] + (int)src[7] + 1) >> 1;
+		}
+
+		if (j < height - 1)
+			memcpy(incache.data(), ptr + stride, 4 * src_width);
+		memcpy(ptr, outcache.data(), 2 * dst_width);
+	}
+}
+
+void downscaleInterleavedUyvy(void *mem, unsigned int height, unsigned int src_width,
+			      unsigned int stride)
+{
+	std::vector<uint8_t> incache(2 * src_width);
+	unsigned int dst_width = src_width / 2;
+	std::vector<uint8_t> outcache(2 * dst_width);
+
+	memcpy(incache.data(), mem, 2 * src_width);
+	for (unsigned int j = 0; j < height; j++) {
+		uint8_t *ptr = (uint8_t *)mem + j * stride;
+
+		uint8_t *src = incache.data(), *dst = outcache.data();
+		for (unsigned int i = 0; i < dst_width; i++, src += 8, dst += 4) {
+			dst[0] = ((int)src[0] + (int)src[4] + 1) >> 1;
+			dst[1] = ((int)src[1] + (int)src[3] + 1) >> 1;
+			dst[2] = ((int)src[2] + (int)src[6] + 1) >> 1;
+			dst[3] = ((int)src[5] + (int)src[7] + 1) >> 1;
+		}
+
+		if (j < height - 1)
+			memcpy(incache.data(), ptr + stride, 4 * src_width);
+		memcpy(ptr, outcache.data(), 2 * dst_width);
+	}
+}
+
+void downscaleInterleaved2Internal(void *mem, unsigned int height, unsigned int src_width,
+				   unsigned int stride, std::vector<uint8_t> &incache,
+				   std::vector<uint8_t> &outcache)
+{
+	unsigned int dst_width = src_width / 2;
+	memcpy(incache.data(), mem, 2 * src_width);
+	for (unsigned int j = 0; j < height; j++) {
+		uint8_t *ptr = (uint8_t *)mem + j * stride;
+
+		uint8_t *src = incache.data(), *dst = outcache.data();
+		for (unsigned int i = 0; i < dst_width; i++, src += 4, dst += 2) {
+			dst[0] = ((int)src[0] + (int)src[2] + 1) >> 1;
+			dst[1] = ((int)src[1] + (int)src[3] + 1) >> 1;
+		}
+
+		if (j < height - 1)
+			memcpy(incache.data(), ptr + stride, 2 * src_width);
+		memcpy(ptr, outcache.data(), 2 * dst_width);
+	}
+}
+
+void downscaleSemiPlanar420(void *memY, void *memUV, unsigned int height,
+			    unsigned int src_width, unsigned int stride)
+{
+	std::vector<uint8_t> incache(src_width);
+	std::vector<uint8_t> outcache(src_width / 2);
+
+	downscalePlaneInternal(memY, height, src_width, stride, incache, outcache);
+	downscaleInterleaved2Internal(memUV, height / 2, src_width / 2, stride,
+				      incache, outcache);
+}
+
+void downscaleStreamBuffer(RPi::Stream *stream, int index)
+{
+	unsigned int downscale = stream->swDownscale();
+	/* Must be a power of 2. */
+	ASSERT((downscale & (downscale - 1)) == 0);
+
+	unsigned int stride = stream->configuration().stride;
+	unsigned int dst_width = stream->configuration().size.width;
+	unsigned int height = stream->configuration().size.height;
+	const PixelFormat &pixFormat = stream->configuration().pixelFormat;
+	const RPi::BufferObject &b = stream->getBuffer(index);
+	void *mem = b.mapped->planes()[0].data();
+	ASSERT(b.mapped);
+
+	/* Do repeated downscale-by-2 in place until we're done. */
+	for (; downscale > 1; downscale >>= 1) {
+		unsigned int src_width = downscale * dst_width;
+
+		if (pixFormat == formats::RGB888 || pixFormat == formats::BGR888) {
+			downscaleInterleaved3(mem, height, src_width, stride);
+		} else if (pixFormat == formats::XRGB8888 || pixFormat == formats::XBGR8888) {
+			/* On some devices these may actually be 24bpp at this point. */
+			if (stream->getFlags() & StreamFlag::Needs32bitConv)
+				downscaleInterleaved3(mem, height, src_width, stride);
+			else
+				downscaleInterleaved4(mem, height, src_width, stride);
+		} else if (pixFormat == formats::YUV420 || pixFormat == formats::YVU420) {
+			/*
+			 * These look "multiplanar" even when they're a single allocation,
+			 * so the following should work for everyone.
+			 */
+			void *mem1 = b.mapped->planes()[1].data();
+			void *mem2 = b.mapped->planes()[2].data();
+			downscalePlanar420(mem, mem1, mem2, height, src_width, stride);
+		} else if (pixFormat == formats::YUV422 || pixFormat == formats::YVU422) {
+			/*
+			 * These look "multiplanar" even when they're a single allocation,
+			 * so the following should work for everyone.
+			 */
+			void *mem1 = b.mapped->planes()[1].data();
+			void *mem2 = b.mapped->planes()[2].data();
+			downscalePlanar422(mem, mem1, mem2, height, src_width, stride);
+		} else if (pixFormat == formats::YUYV || pixFormat == formats::YVYU) {
+			downscaleInterleavedYuyv(mem, height, src_width, stride);
+		} else if (pixFormat == formats::UYVY || pixFormat == formats::VYUY) {
+			downscaleInterleavedUyvy(mem, height, src_width, stride);
+		} else if (pixFormat == formats::NV12 || pixFormat == formats::NV21) {
+			/*
+			 * These look "multiplanar" even when they're a single allocation,
+			 * so the following should work for everyone.
+			 */
+			void *mem1 = b.mapped->planes()[1].data();
+			downscaleSemiPlanar420(mem, mem1, height, src_width, stride);
+		} else {
+			LOG(RPI, Error) << "Sw downscale unsupported for " << pixFormat;
+			ASSERT(0);
+		}
+	}
+}
+
+/* Return largest width of any of these streams (or of the camera input). */
+unsigned int getLargestWidth(const V4L2SubdeviceFormat &sensorFormat,
+			     const std::vector<StreamParams> &outStreams)
+{
+	unsigned int largestWidth = sensorFormat.size.width;
+
+	for (const auto &stream : outStreams)
+		largestWidth = std::max(largestWidth, stream.cfg->size.width);
+
+	return largestWidth;
+}
+
+/* Return the minimum number of pixels required to write out multiples of 16 bytes. */
+unsigned int getFormatAlignment(const V4L2PixelFormat &fourcc)
+{
+	const PixelFormatInfo &info = PixelFormatInfo::info(fourcc);
+	unsigned int formatAlignment = 0;
+	for (const auto &plane : info.planes) {
+		if (plane.bytesPerGroup) {
+			/* How many pixels we need in this plane for a multiple of 16 bytes (??). */
+			unsigned int align = 16 * info.pixelsPerGroup /
+						std::gcd(16u, plane.bytesPerGroup);
+			formatAlignment = std::max(formatAlignment, align);
+		}
+	}
+
+	return formatAlignment;
+}
+
+/* Calculate the amount of software downscale required (which is a power of 2). */
+unsigned int calculateSwDownscale(const V4L2DeviceFormat &format, unsigned int largestWidth,
+				  unsigned int platformMaxDownscale)
+{
+	unsigned int formatAlignment = getFormatAlignment(format.fourcc);
+	unsigned int maxDownscale = platformMaxDownscale * 16 / formatAlignment;
+	unsigned int limitWidth = largestWidth / maxDownscale;
+
+	unsigned int hwWidth = format.size.width;
+	unsigned int swDownscale = 1;
+	for (; hwWidth < limitWidth; hwWidth *= 2, swDownscale *= 2);
+
+	return swDownscale;
+}
+
+} /* namespace */
+
+using ::libpisp::BackEnd;
+using ::libpisp::FrontEnd;
+
+class PiSPCameraData final : public RPi::CameraData
+{
+public:
+	PiSPCameraData(PipelineHandler *pipe, const libpisp::PiSPVariant &variant)
+		: RPi::CameraData(pipe), pispVariant_(variant)
+	{
+		/* Initialise internal libpisp logging. */
+		::libpisp::logging_init();
+		LOG(RPI, Info) << "libpisp version " << ::libpisp::version();
+	}
+
+	~PiSPCameraData()
+	{
+		freeBuffers();
+	}
+
+	V4L2VideoDevice::Formats ispFormats() const override
+	{
+		return isp_[Isp::Output0].dev()->formats();
+	}
+
+	V4L2VideoDevice::Formats rawFormats() const override
+	{
+		return cfe_[Cfe::Output0].dev()->formats();
+	}
+
+	V4L2VideoDevice *frontendDevice() override
+	{
+		return cfe_[Cfe::Output0].dev();
+	}
+
+	CameraConfiguration::Status
+	platformValidate(RPi::RPiCameraConfiguration *rpiConfig) const override;
+
+	int platformPipelineConfigure(const std::unique_ptr<YamlObject> &root) override;
+
+	void platformStart() override;
+	void platformStop() override;
+	void platformFreeBuffers() override;
+
+	void cfeBufferDequeue(FrameBuffer *buffer);
+	void beInputDequeue(FrameBuffer *buffer);
+	void beOutputDequeue(FrameBuffer *buffer);
+
+	void processStatsComplete(const ipa::RPi::BufferIds &buffers);
+	void prepareIspComplete(const ipa::RPi::BufferIds &buffers, bool stitchSwapBuffers);
+	void setCameraTimeout(uint32_t maxFrameLengthMs);
+
+	/* Array of CFE and ISP device streams and associated buffers/streams. */
+	RPi::Device<Cfe, 4> cfe_;
+	RPi::Device<Isp, 8> isp_;
+
+	const libpisp::PiSPVariant &pispVariant_;
+
+	/* Frontend/Backend objects shared with the IPA. */
+	RPi::SharedMemObject<FrontEnd> fe_;
+	RPi::SharedMemObject<BackEnd> be_;
+	bool beEnabled_;
+
+	std::unique_ptr<V4L2Subdevice> csi2Subdev_;
+	std::unique_ptr<V4L2Subdevice> feSubdev_;
+
+	std::vector<FrameBuffer *> tdnBuffers_;
+	std::vector<FrameBuffer *> stitchBuffers_;
+	unsigned int tdnInputIndex_;
+	unsigned int stitchInputIndex_;
+
+	struct Config {
+		/*
+		 * Number of CFE config and stats buffers to allocate and use. A
+		 * larger number minimises the possibility of dropping frames,
+		 * but increases the latency for updating the HW configuration.
+		 */
+		unsigned int numCfeConfigStatsBuffers;
+		/*
+		 * Number of jobs to queue ahead to the CFE on startup.
+		 * A larger number will increase latency for 3A changes.
+		 */
+		unsigned int numCfeConfigQueue;
+		/* Don't use BE temporal denoise and free some memory resources. */
+		bool disableTdn;
+		/* Don't use BE HDR and free some memory resources. */
+		bool disableHdr;
+	};
+
+	Config config_;
+
+	bool adjustDeviceFormat(V4L2DeviceFormat &format) const;
+
+private:
+	int platformConfigure(const RPi::RPiCameraConfiguration *rpiConfig) override;
+
+	int platformConfigureIpa([[maybe_unused]] ipa::RPi::ConfigParams &params) override
+	{
+		return 0;
+	}
+
+	int platformInitIpa(ipa::RPi::InitParams &params) override;
+
+	int configureEntities(V4L2SubdeviceFormat sensorFormat,
+			      V4L2SubdeviceFormat &embeddedFormat);
+	int configureCfe();
+	bool calculateCscConfiguration(const V4L2DeviceFormat &v4l2Format, pisp_be_ccm_config &csc);
+	int configureBe(const std::optional<ColorSpace> &yuvColorSpace);
+
+	void platformSetIspCrop() override;
+
+	void prepareCfe();
+	void prepareBe(uint32_t bufferId, bool stitchSwapBuffers);
+
+	void tryRunPipeline() override;
+
+	struct CfeJob {
+		ControlList sensorControls;
+		unsigned int delayContext;
+		std::unordered_map<const RPi::Stream *, FrameBuffer *> buffers;
+	};
+
+	std::queue<CfeJob> cfeJobQueue_;
+
+	bool cfeJobComplete() const
+	{
+		if (cfeJobQueue_.empty())
+			return false;
+
+		const CfeJob &job = cfeJobQueue_.back();
+		return job.buffers.count(&cfe_[Cfe::Output0]) &&
+		       job.buffers.count(&cfe_[Cfe::Stats]) &&
+		       (!sensorMetadata_ ||
+				job.buffers.count(&cfe_[Cfe::Embedded]));
+	}
+
+	std::string last_dump_file_;
+};
+
+class PipelineHandlerPiSP : public RPi::PipelineHandlerBase
+{
+public:
+	PipelineHandlerPiSP(CameraManager *manager)
+		: RPi::PipelineHandlerBase(manager)
+	{
+	}
+
+	~PipelineHandlerPiSP()
+	{
+	}
+
+	bool match(DeviceEnumerator *enumerator) override;
+
+private:
+	PiSPCameraData *cameraData(Camera *camera)
+	{
+		return static_cast<PiSPCameraData *>(camera->_d());
+	}
+
+	int prepareBuffers(Camera *camera) override;
+	int platformRegister(std::unique_ptr<RPi::CameraData> &cameraData,
+			     MediaDevice *cfe, MediaDevice *isp) override;
+};
+
+bool PipelineHandlerPiSP::match(DeviceEnumerator *enumerator)
+{
+	constexpr unsigned int numCfeDevices = 2;
+
+	/*
+	 * Loop over all CFE instances, but return out once a match is found.
+	 * This is to ensure we correctly enumerate the camera when an instance
+	 * of the CFE has registered with media controller, but has not registered
+	 * device nodes due to a sensor subdevice failure.
+	 */
+	for (unsigned int i = 0; i < numCfeDevices; i++) {
+		DeviceMatch cfe("rp1-cfe");
+		cfe.add("rp1-cfe-fe_image0");
+		cfe.add("rp1-cfe-fe_stats");
+		cfe.add("rp1-cfe-fe_config");
+		MediaDevice *cfeDevice = acquireMediaDevice(enumerator, cfe);
+
+		if (!cfeDevice) {
+			LOG(RPI, Debug) << "Unable to acquire a CFE instance";
+			break;
+		}
+
+		DeviceMatch isp("pispbe");
+		isp.add("pispbe-input");
+		isp.add("pispbe-config");
+		isp.add("pispbe-output0");
+		isp.add("pispbe-output1");
+		isp.add("pispbe-tdn_output");
+		isp.add("pispbe-tdn_input");
+		isp.add("pispbe-stitch_output");
+		isp.add("pispbe-stitch_input");
+		MediaDevice *ispDevice = acquireMediaDevice(enumerator, isp);
+
+		if (!ispDevice) {
+			LOG(RPI, Debug) << "Unable to acquire ISP instance";
+			break;
+		}
+
+		/*
+		 * The loop below is used to register multiple cameras behind
+		 * one or more video mux devices that are attached to a
+		 * particular CFE instance. Obviously these cameras cannot be
+		 * used simultaneously.
+		 */
+		unsigned int numCameras = 0;
+		for (MediaEntity *entity : cfeDevice->entities()) {
+			if (entity->function() != MEDIA_ENT_F_CAM_SENSOR)
+				continue;
+
+			const libpisp::PiSPVariant &variant =
+				libpisp::get_variant(cfeDevice->hwRevision(),
+						     ispDevice->hwRevision());
+			if (!variant.NumFrontEnds() || !variant.NumBackEnds()) {
+				LOG(RPI, Error) << "Unsupported PiSP variant";
+				break;
+			}
+
+			std::unique_ptr<RPi::CameraData> cameraData =
+				std::make_unique<PiSPCameraData>(this, variant);
+			PiSPCameraData *pisp =
+				static_cast<PiSPCameraData *>(cameraData.get());
+
+			pisp->fe_ = RPi::SharedMemObject<FrontEnd>
+					("pisp_frontend", true, pisp->pispVariant_);
+			pisp->be_ = RPi::SharedMemObject<BackEnd>
+					("pisp_backend", BackEnd::Config({}), pisp->pispVariant_);
+
+			if (!pisp->fe_.fd().isValid() || !pisp->be_.fd().isValid()) {
+				LOG(RPI, Error) << "Failed to create ISP shared objects";
+				break;
+			}
+
+			int ret = registerCamera(cameraData, cfeDevice, "csi2",
+						 ispDevice, entity);
+			if (ret)
+				LOG(RPI, Error) << "Failed to register camera "
+						<< entity->name() << ": " << ret;
+			else
+				numCameras++;
+		}
+
+		if (numCameras)
+			return true;
+	}
+
+	return false;
+}
+
+int PipelineHandlerPiSP::prepareBuffers(Camera *camera)
+{
+	PiSPCameraData *data = cameraData(camera);
+	unsigned int numRawBuffers = 0;
+	int ret;
+
+	for (Stream *s : camera->streams()) {
+		if (PipelineHandlerBase::isRaw(s->configuration().pixelFormat)) {
+			numRawBuffers = s->configuration().bufferCount;
+			break;
+		}
+	}
+
+	/* Decide how many internal buffers to allocate. */
+	for (auto const stream : data->streams_) {
+		unsigned int numBuffers;
+		/*
+		 * For CFE, allocate a minimum of 4 buffers as we want
+		 * to avoid any frame drops.
+		 */
+		constexpr unsigned int minBuffers = 4;
+		if (stream == &data->cfe_[Cfe::Output0]) {
+			/*
+			 * If an application has configured a RAW stream, allocate
+			 * additional buffers to make up the minimum, but ensure
+			 * we have at least 2 sets of internal buffers to use to
+			 * minimise frame drops.
+			 */
+			numBuffers = std::max<int>(2, minBuffers - numRawBuffers);
+		} else if (stream == &data->isp_[Isp::Input]) {
+			/*
+			 * ISP input buffers are imported from the CFE, so follow
+			 * similar logic as above to count all the RAW buffers
+			 * available.
+			 */
+			numBuffers = numRawBuffers +
+					std::max<int>(2, minBuffers - numRawBuffers);
+		} else if (stream == &data->cfe_[Cfe::Embedded]) {
+			/*
+			 * Embedded data buffers are (currently) for internal use,
+			 * so allocate a reasonably large amount.
+			 */
+			numBuffers = 12;
+		} else if (stream == &data->cfe_[Cfe::Stats] ||
+			   stream == &data->cfe_[Cfe::Config]) {
+			numBuffers = data->config_.numCfeConfigStatsBuffers;
+		} else if (!data->beEnabled_) {
+			/* Backend not enabled, we don't need to allocate buffers. */
+			numBuffers = 0;
+		} else if (stream == &data->isp_[Isp::TdnOutput] && data->config_.disableTdn) {
+			/* TDN is explicitly disabled. */
+			continue;
+		} else if (stream == &data->isp_[Isp::StitchOutput] && data->config_.disableHdr) {
+			/* Stitch/HDR is explicitly disabled. */
+			continue;
+		} else {
+			/* Allocate 2 sets of all other Backend buffers */
+			numBuffers = 2;
+		}
+
+		LOG(RPI, Debug) << "Preparing " << numBuffers
+				<< " buffers for stream " << stream->name();
+
+		ret = stream->prepareBuffers(numBuffers);
+		if (ret < 0)
+			return ret;
+	}
+
+	/*
+	 * Store the Framebuffer pointers for convenience as we will ping-pong
+	 * these buffers between the input and output nodes for TDN and Stitch.
+	 *
+	 * The buffer size needs to be setup here as well. Conveniently this is
+	 * the same for both TDN and stitch.
+	 */
+	pisp_image_format_config tdn;
+	data->be_->GetTdnOutputFormat(tdn);
+	unsigned int size = tdn.stride * tdn.height;
+	for (auto const &buffer : data->isp_[Isp::TdnOutput].getBuffers()) {
+		FrameBuffer *b = buffer.second.buffer;
+		b->_d()->metadata().planes()[0].bytesused = size;
+		data->tdnBuffers_.push_back(b);
+	}
+	for (auto const &buffer : data->isp_[Isp::StitchOutput].getBuffers()) {
+		FrameBuffer *b = buffer.second.buffer;
+		b->_d()->metadata().planes()[0].bytesused = size;
+		data->stitchBuffers_.push_back(b);
+	}
+
+	/* Size up the config buffers as well. */
+	for (auto &b : data->isp_[Isp::Config].getBuffers()) {
+		FrameMetadata::Plane &plane = b.second.buffer->_d()->metadata().planes()[0];
+		plane.bytesused = sizeof(pisp_be_tiles_config);
+	}
+
+	/*
+	 * Pass the stats and embedded data buffers to the IPA. No other
+	 * buffers need to be passed.
+	 */
+	mapBuffers(camera, data->cfe_[Cfe::Stats].getBuffers(), RPi::MaskStats);
+	if (data->sensorMetadata_)
+		mapBuffers(camera, data->cfe_[Cfe::Embedded].getBuffers(),
+			   RPi::MaskEmbeddedData);
+
+	return 0;
+}
+
+int PipelineHandlerPiSP::platformRegister(std::unique_ptr<RPi::CameraData> &cameraData,
+					  MediaDevice *cfe, MediaDevice *isp)
+{
+	PiSPCameraData *data = static_cast<PiSPCameraData *>(cameraData.get());
+	int ret;
+
+	MediaEntity *cfeImage = cfe->getEntityByName("rp1-cfe-fe_image0");
+	MediaEntity *cfeEmbedded = cfe->getEntityByName("rp1-cfe-embedded");
+	MediaEntity *cfeStats = cfe->getEntityByName("rp1-cfe-fe_stats");
+	MediaEntity *cfeConfig = cfe->getEntityByName("rp1-cfe-fe_config");
+	MediaEntity *ispInput = isp->getEntityByName("pispbe-input");
+	MediaEntity *IpaPrepare = isp->getEntityByName("pispbe-config");
+	MediaEntity *ispOutput0 = isp->getEntityByName("pispbe-output0");
+	MediaEntity *ispOutput1 = isp->getEntityByName("pispbe-output1");
+	MediaEntity *ispTdnOutput = isp->getEntityByName("pispbe-tdn_output");
+	MediaEntity *ispTdnInput = isp->getEntityByName("pispbe-tdn_input");
+	MediaEntity *ispStitchOutput = isp->getEntityByName("pispbe-stitch_output");
+	MediaEntity *ispStitchInput = isp->getEntityByName("pispbe-stitch_input");
+
+	/* Locate and open the cfe video streams. */
+	data->cfe_[Cfe::Output0] = RPi::Stream("CFE Image", cfeImage);
+	data->cfe_[Cfe::Embedded] = RPi::Stream("CFE Embedded", cfeEmbedded);
+	data->cfe_[Cfe::Stats] = RPi::Stream("CFE Stats", cfeStats);
+	data->cfe_[Cfe::Config] = RPi::Stream("CFE Config", cfeConfig,
+					      StreamFlag::Recurrent | StreamFlag::RequiresMmap);
+
+	/* Tag the ISP input stream as an import stream. */
+	data->isp_[Isp::Input] =
+		RPi::Stream("ISP Input", ispInput, StreamFlag::ImportOnly);
+	data->isp_[Isp::Config] =
+		RPi::Stream("ISP Config", IpaPrepare, StreamFlag::Recurrent |
+						      StreamFlag::RequiresMmap);
+	data->isp_[Isp::Output0] =
+		RPi::Stream("ISP Output0", ispOutput0, StreamFlag::RequiresMmap);
+	data->isp_[Isp::Output1] =
+		RPi::Stream("ISP Output1", ispOutput1, StreamFlag::RequiresMmap);
+	data->isp_[Isp::TdnOutput] =
+		RPi::Stream("ISP TDN Output", ispTdnOutput, StreamFlag::Recurrent);
+	data->isp_[Isp::TdnInput] =
+		RPi::Stream("ISP TDN Input", ispTdnInput, StreamFlag::ImportOnly |
+							  StreamFlag::Recurrent);
+	data->isp_[Isp::StitchOutput] =
+		RPi::Stream("ISP Stitch Output", ispStitchOutput, StreamFlag::Recurrent);
+	data->isp_[Isp::StitchInput] =
+		RPi::Stream("ISP Stitch Input", ispStitchInput, StreamFlag::ImportOnly |
+								StreamFlag::Recurrent);
+
+	/* Wire up all the buffer connections. */
+	data->cfe_[Cfe::Output0].dev()->bufferReady.connect(data, &PiSPCameraData::cfeBufferDequeue);
+	data->cfe_[Cfe::Stats].dev()->bufferReady.connect(data, &PiSPCameraData::cfeBufferDequeue);
+	data->cfe_[Cfe::Config].dev()->bufferReady.connect(data, &PiSPCameraData::cfeBufferDequeue);
+	data->isp_[Isp::Input].dev()->bufferReady.connect(data, &PiSPCameraData::beInputDequeue);
+	data->isp_[Isp::Config].dev()->bufferReady.connect(data, &PiSPCameraData::beOutputDequeue);
+	data->isp_[Isp::Output0].dev()->bufferReady.connect(data, &PiSPCameraData::beOutputDequeue);
+	data->isp_[Isp::Output1].dev()->bufferReady.connect(data, &PiSPCameraData::beOutputDequeue);
+	data->cfe_[Cfe::Embedded].dev()->bufferReady.connect(data, &PiSPCameraData::cfeBufferDequeue);
+
+	data->csi2Subdev_ = std::make_unique<V4L2Subdevice>(cfe->getEntityByName("csi2"));
+	data->feSubdev_ = std::make_unique<V4L2Subdevice>(cfe->getEntityByName("pisp-fe"));
+	data->csi2Subdev_->open();
+	data->feSubdev_->open();
+
+	/*
+	 * Open all CFE and ISP streams. The exception is the embedded data
+	 * stream, which only gets opened below if the IPA reports that the sensor
+	 * supports embedded data.
+	 *
+	 * The below grouping is just for convenience so that we can easily
+	 * iterate over all streams in one go.
+	 */
+	data->streams_.push_back(&data->cfe_[Cfe::Output0]);
+	data->streams_.push_back(&data->cfe_[Cfe::Config]);
+	data->streams_.push_back(&data->cfe_[Cfe::Stats]);
+	if (data->sensorMetadata_)
+		data->streams_.push_back(&data->cfe_[Cfe::Embedded]);
+
+	data->streams_.push_back(&data->isp_[Isp::Input]);
+	data->streams_.push_back(&data->isp_[Isp::Output0]);
+	data->streams_.push_back(&data->isp_[Isp::Output1]);
+	data->streams_.push_back(&data->isp_[Isp::Config]);
+	data->streams_.push_back(&data->isp_[Isp::TdnInput]);
+	data->streams_.push_back(&data->isp_[Isp::TdnOutput]);
+	data->streams_.push_back(&data->isp_[Isp::StitchInput]);
+	data->streams_.push_back(&data->isp_[Isp::StitchOutput]);
+
+	for (auto stream : data->streams_) {
+		ret = stream->dev()->open();
+		if (ret)
+			return ret;
+	}
+
+	/* Write up all the IPA connections. */
+	data->ipa_->prepareIspComplete.connect(data, &PiSPCameraData::prepareIspComplete);
+	data->ipa_->processStatsComplete.connect(data, &PiSPCameraData::processStatsComplete);
+	data->ipa_->setCameraTimeout.connect(data, &PiSPCameraData::setCameraTimeout);
+
+	/*
+	 * List the available streams an application may request. At present, we
+	 * do not advertise CFE Embedded and ISP Statistics streams, as there
+	 * is no mechanism for the application to request non-image buffer formats.
+	 */
+	std::set<Stream *> streams;
+	streams.insert(&data->cfe_[Cfe::Output0]);
+	streams.insert(&data->isp_[Isp::Output0]);
+	streams.insert(&data->isp_[Isp::Output1]);
+
+	/* Create and register the camera. */
+	const std::string &id = data->sensor_->id();
+	std::shared_ptr<Camera> camera =
+		Camera::create(std::move(cameraData), id, streams);
+	PipelineHandler::registerCamera(std::move(camera));
+
+	LOG(RPI, Info) << "Registered camera " << id
+		       << " to CFE device " << cfe->deviceNode()
+		       << " and ISP device " << isp->deviceNode()
+		       << " using PiSP variant " << data->pispVariant_.Name();
+
+	return 0;
+}
+
+CameraConfiguration::Status
+PiSPCameraData::platformValidate(RPi::RPiCameraConfiguration *rpiConfig) const
+{
+	std::vector<StreamParams> &rawStreams = rpiConfig->rawStreams_;
+	std::vector<StreamParams> &outStreams = rpiConfig->outStreams_;
+
+	CameraConfiguration::Status status = CameraConfiguration::Status::Valid;
+
+	/* Can only output 1 RAW stream and/or 2 YUV/RGB streams for now. */
+	if (rawStreams.size() > 1 || outStreams.size() > 2) {
+		LOG(RPI, Error) << "Invalid number of streams requested";
+		return CameraConfiguration::Status::Invalid;
+	}
+
+	if (!rawStreams.empty()) {
+		rawStreams[0].dev = cfe_[Cfe::Output0].dev();
+
+		StreamConfiguration *rawStream = rawStreams[0].cfg;
+		BayerFormat bayer = BayerFormat::fromPixelFormat(rawStream->pixelFormat);
+		/*
+		 * We cannot output CSI2 packed or non 16-bit output from the frontend,
+		 * so signal the output as unpacked 16-bits in these cases.
+		 */
+		if (bayer.packing == BayerFormat::Packing::CSI2 || bayer.bitDepth != 16) {
+			bayer.packing = bayer.packing == BayerFormat::Packing::CSI2 ?
+						BayerFormat::Packing::PISP1 : BayerFormat::Packing::None;
+			bayer.bitDepth = 16;
+		}
+
+		/* The RAW stream size cannot exceed the sensor frame output - for now. */
+		if (rawStream->size != rpiConfig->sensorFormat_.size ||
+		    rawStream->pixelFormat != bayer.toPixelFormat()) {
+			rawStream->size = rpiConfig->sensorFormat_.size;
+			rawStream->pixelFormat = bayer.toPixelFormat();
+			status = CameraConfiguration::Adjusted;
+		}
+
+		rawStreams[0].format =
+			RPi::PipelineHandlerBase::toV4L2DeviceFormat(cfe_[Cfe::Output0].dev(), rawStream);
+
+		computeOptimalStride(rawStreams[0].format);
+	}
+
+	/*
+	 * For the two ISP outputs, the lower resolution must be routed from
+	 * Output 1
+	 *
+	 * Index 0 contains the largest requested resolution.
+	 */
+	unsigned int largestWidth = getLargestWidth(rpiConfig->sensorFormat_,
+						    rpiConfig->outStreams_);
+
+	for (unsigned int i = 0; i < outStreams.size(); i++) {
+		StreamConfiguration *cfg = outStreams[i].cfg;
+
+		/*
+		 * Output 1 must be for the smallest resolution. We will
+		 * have that fixed up in the code above.
+		 */
+		auto ispOutput = i == 1 || outStreams.size() == 1 ? Isp::Output1
+								  : Isp::Output0;
+		outStreams[i].dev = isp_[ispOutput].dev();
+
+		/*
+		 * Don't let The output streams downscale by more than 64x when
+		 * a downscaler block is available, or 16x when there's only the
+		 * resampler.
+		 */
+		Size rawSize = rpiConfig->sensorFormat_.size.boundedToAspectRatio(cfg->size);
+		unsigned int outputIndex = ispOutput == Isp::Output0 ? 0 : 1;
+		Size minSize;
+		if (pispVariant_.BackEndDownscalerAvailable(0, outputIndex)) {
+			/*
+			 * Downscaler available. Allow up to 64x downscale. If not a multiple of
+			 * 64, round up to the next integer, but also ensure the result is even.
+			 */
+			const unsigned int downscale = 64;
+			minSize.width = (rawSize.width + downscale - 1) / downscale;
+			minSize.width = (minSize.width + 1) & ~1; /* ensure even */
+			minSize.height = (rawSize.height + downscale - 1) / downscale;
+			minSize.height = (minSize.height + 1) & ~1; /* ensure even */
+		} else {
+			/* No downscale. Resampler requires: (output_dim - 1) * 16 <= input_dim - 1 */
+			const unsigned int downscale = 16;
+			minSize.width = (rawSize.width - 1 + downscale - 1) / downscale + 1;
+			minSize.width = (minSize.width + 1) & ~1; /* ensure even */
+			minSize.height = (rawSize.height - 1 + downscale - 1) / downscale + 1;
+			minSize.height = (minSize.height + 1) & ~1; /* ensure even */
+		}
+		LOG(RPI, Debug) << "minSize: width " << minSize.width << " height " << minSize.height;
+
+		/* Bound the output size to minSize, preserve aspect ratio, and ensure even numbers. */
+		if (cfg->size.width < minSize.width) {
+			cfg->size.height = (cfg->size.height * minSize.width / cfg->size.width + 1) & ~1;
+			cfg->size.width = minSize.width;
+			status = CameraConfiguration::Status::Adjusted;
+		}
+
+		if (cfg->size.height < minSize.height) {
+			cfg->size.width = (cfg->size.width * minSize.height / cfg->size.height + 1) & ~1;
+			cfg->size.height = minSize.height;
+			status = CameraConfiguration::Status::Adjusted;
+		}
+
+		/* Make sure output1 is no larger than output 0. */
+		Size size = cfg->size.boundedTo(outStreams[0].cfg->size);
+
+		/* \todo Warn if upscaling: reduces image quality. */
+
+		if (cfg->size != size) {
+			cfg->size = size;
+			status = CameraConfiguration::Status::Adjusted;
+		}
+
+		outStreams[i].format =
+			RPi::PipelineHandlerBase::toV4L2DeviceFormat(outStreams[i].dev, outStreams[i].cfg);
+
+		/* Compute the optimal stride for the BE output buffers. */
+		computeOptimalStride(outStreams[i].format);
+
+		/*
+		 * We need to check for software downscaling. This must happen
+		 * after adjusting the device format so that we can choose the
+		 * largest stride - which might have been the original
+		 * unadjusted format, or the adjusted one (if software
+		 * downscaling means it's larger).
+		 */
+		V4L2DeviceFormat adjustedFormat = outStreams[i].format;
+		adjustDeviceFormat(adjustedFormat);
+
+		unsigned int swDownscale =
+			calculateSwDownscale(adjustedFormat, largestWidth,
+					     be_->GetMaxDownscale());
+		LOG(RPI, Debug) << "For stream " << adjustedFormat
+				<< " swDownscale is " << swDownscale;
+		if (swDownscale > 1) {
+			adjustedFormat.size.width *= swDownscale;
+			computeOptimalStride(adjustedFormat);
+			for (unsigned int p = 0; p < outStreams[i].format.planesCount; p++)
+				outStreams[i].format.planes[p].bpl =
+					std::max(outStreams[i].format.planes[p].bpl, adjustedFormat.planes[p].bpl);
+		}
+	}
+
+	return status;
+}
+
+int PiSPCameraData::platformPipelineConfigure(const std::unique_ptr<YamlObject> &root)
+{
+	config_ = {
+		.numCfeConfigStatsBuffers = 12,
+		.numCfeConfigQueue = 2,
+		.disableTdn = false,
+		.disableHdr = false,
+	};
+
+	if (!root)
+		return 0;
+
+	std::optional<double> ver = (*root)["version"].get<double>();
+	if (!ver || *ver != 1.0) {
+		LOG(RPI, Error) << "Unexpected configuration file version reported";
+		return -EINVAL;
+	}
+
+	std::optional<std::string> target = (*root)["target"].get<std::string>();
+	if (!target || *target != "pisp") {
+		LOG(RPI, Error) << "Unexpected target reported: expected \"pisp\", got "
+				<< *target;
+		return -EINVAL;
+	}
+
+	const YamlObject &phConfig = (*root)["pipeline_handler"];
+	config_.numCfeConfigStatsBuffers =
+		phConfig["num_cfe_config_stats_buffers"].get<unsigned int>(config_.numCfeConfigStatsBuffers);
+	config_.numCfeConfigQueue =
+		phConfig["num_cfe_config_queue"].get<unsigned int>(config_.numCfeConfigQueue);
+	config_.disableTdn = phConfig["disable_tdn"].get<bool>(config_.disableTdn);
+	config_.disableHdr = phConfig["disable_hdr"].get<bool>(config_.disableHdr);
+
+	if (config_.disableTdn) {
+		LOG(RPI, Info) << "TDN disabled by user config";
+		streams_.erase(std::remove_if(streams_.begin(), streams_.end(),
+			       [this] (const RPi::Stream *s) { return s == &isp_[Isp::TdnInput] ||
+								      s == &isp_[Isp::TdnInput]; }),
+			       streams_.end());
+	}
+
+	if (config_.disableHdr) {
+		LOG(RPI, Info) << "HDR disabled by user config";
+		streams_.erase(std::remove_if(streams_.begin(), streams_.end(),
+			       [this] (const RPi::Stream *s) { return s == &isp_[Isp::StitchInput] ||
+								      s == &isp_[Isp::StitchOutput]; }),
+			       streams_.end());
+	}
+
+	if (config_.numCfeConfigStatsBuffers < 1) {
+		LOG(RPI, Error)
+			<< "Invalid configuration: num_cfe_config_stats_buffers must be >= 1";
+		return -EINVAL;
+	}
+
+	if (config_.numCfeConfigQueue < 1) {
+		LOG(RPI, Error)
+			<< "Invalid configuration: numCfeConfigQueue must be >= 1";
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+std::unordered_map<uint32_t, uint32_t> deviceAdjustTable = {
+	{ V4L2_PIX_FMT_RGBX32, V4L2_PIX_FMT_RGB24 },
+	{ V4L2_PIX_FMT_XBGR32, V4L2_PIX_FMT_BGR24 }
+};
+
+bool PiSPCameraData::adjustDeviceFormat(V4L2DeviceFormat &format) const
+{
+	auto it = deviceAdjustTable.find(format.fourcc.fourcc());
+
+	if (pispVariant_.BackendRGB32Supported(0))
+		return false;
+
+	if (it != deviceAdjustTable.end()) {
+		LOG(RPI, Debug) << "Swapping 32-bit for 24-bit format";
+		format.fourcc = V4L2PixelFormat(it->second);
+		return true;
+	}
+
+	return false;
+}
+
+int PiSPCameraData::platformConfigure(const RPi::RPiCameraConfiguration *rpiConfig)
+{
+	const std::vector<RPi::RPiCameraConfiguration::StreamParams> &rawStreams = rpiConfig->rawStreams_;
+	const std::vector<RPi::RPiCameraConfiguration::StreamParams> &outStreams = rpiConfig->outStreams_;
+	int ret;
+
+	V4L2VideoDevice *cfe = cfe_[Cfe::Output0].dev();
+	V4L2DeviceFormat cfeFormat;
+
+	/*
+	 * See which streams are requested, and route the user
+	 * StreamConfiguration appropriately.
+	 */
+	if (rawStreams.empty()) {
+		/*
+		 * The CFE Frontend output will always be 16-bits unpacked, so adjust the
+		 * mbus code right at the start.
+		 */
+		V4L2SubdeviceFormat sensorFormatMod = rpiConfig->sensorFormat_;
+		sensorFormatMod.mbus_code = mbusCodeUnpacked16(sensorFormatMod.mbus_code);
+		cfeFormat = RPi::PipelineHandlerBase::toV4L2DeviceFormat(cfe,
+									 sensorFormatMod,
+									 BayerFormat::Packing::PISP1);
+		computeOptimalStride(cfeFormat);
+	} else {
+		rawStreams[0].cfg->setStream(&cfe_[Cfe::Output0]);
+		cfe_[Cfe::Output0].setFlags(StreamFlag::External);
+		cfeFormat = rawStreams[0].format;
+	}
+
+	ret = cfe->setFormat(&cfeFormat);
+	if (ret)
+		return ret;
+
+	/* Set the TDN and Stitch node formats in case they are turned on. */
+	isp_[Isp::TdnOutput].dev()->setFormat(&cfeFormat);
+	isp_[Isp::TdnInput].dev()->setFormat(&cfeFormat);
+	isp_[Isp::StitchOutput].dev()->setFormat(&cfeFormat);
+	isp_[Isp::StitchInput].dev()->setFormat(&cfeFormat);
+
+	ret = isp_[Isp::Input].dev()->setFormat(&cfeFormat);
+	if (ret)
+		return ret;
+
+	LOG(RPI, Info) << "Sensor: " << sensor_->id()
+		       << " - Selected sensor format: " << rpiConfig->sensorFormat_
+		       << " - Selected CFE format: " << cfeFormat;
+
+	/*
+	 * Find the largest width of any stream; we'll use it later to check for
+	 * excessive downscaling.
+	 */
+	unsigned int largestWidth = getLargestWidth(rpiConfig->sensorFormat_, outStreams);
+
+	unsigned int beEnables = 0;
+	V4L2DeviceFormat format;
+
+	/*
+	 * First thing is to remove Isp::Output0 and Isp::Output1 from streams_
+	 * as they may be unused depending on the configuration. Add them back
+	 * only if needed.
+	 */
+	streams_.erase(std::remove_if(streams_.begin(), streams_.end(),
+		       [this] (const RPi::Stream *s) { return s == &isp_[Isp::Output0] ||
+							      s == &isp_[Isp::Output1]; }),
+		       streams_.end());
+
+	for (unsigned int i = 0; i < outStreams.size(); i++) {
+		StreamConfiguration *cfg = outStreams[i].cfg;
+
+		/*
+		 * Output 1 must be for the smallest resolution. We will
+		 * have that fixed up in the code above.
+		 */
+		RPi::Stream *stream;
+		if (i == 1 || outStreams.size() == 1) {
+			stream = &isp_[Isp::Output1];
+			beEnables |= PISP_BE_RGB_ENABLE_OUTPUT1;
+		} else {
+			stream = &isp_[Isp::Output0];
+			beEnables |= PISP_BE_RGB_ENABLE_OUTPUT0;
+		}
+
+		format = outStreams[i].format;
+		bool needs32BitConversion = adjustDeviceFormat(format);
+
+		/*
+		 * This pixel format may not be the same as the configured
+		 * pixel format if adjustDeviceFormat() above has reqused a change.
+		 */
+		PixelFormat pixFmt = format.fourcc.toPixelFormat();
+
+		/* If there's excessive downscaling we'll do some of it in software. */
+		unsigned int swDownscale = calculateSwDownscale(format, largestWidth,
+								be_->GetMaxDownscale());
+		unsigned int hwWidth = format.size.width * swDownscale;
+		format.size.width = hwWidth;
+
+		LOG(RPI, Debug) << "Setting " << stream->name() << " to "
+				<< format << " (sw downscale " << swDownscale << ")";
+
+		ret = stream->dev()->setFormat(&format);
+		if (ret)
+			return -EINVAL;
+		LOG(RPI, Debug) << "After setFormat, stride " << format.planes[0].bpl;
+
+		if (format.size.height != cfg->size.height ||
+		    format.size.width != hwWidth || format.fourcc.toPixelFormat() != pixFmt) {
+			LOG(RPI, Error)
+				<< "Failed to set requested format on " << stream->name()
+				<< ", returned " << format;
+			return -EINVAL;
+		}
+
+		LOG(RPI, Debug)
+			<< "Stream " << stream->name() << " has color space "
+			<< ColorSpace::toString(cfg->colorSpace);
+
+		libcamera::RPi::Stream::StreamFlags flags = StreamFlag::External;
+
+		stream->clearFlags(StreamFlag::Needs32bitConv);
+		if (needs32BitConversion)
+			flags |= StreamFlag::Needs32bitConv;
+
+		cfg->setStream(stream);
+		stream->setFlags(flags);
+		stream->setSwDownscale(swDownscale);
+		streams_.push_back(stream);
+	}
+
+	pisp_be_global_config global;
+	be_->GetGlobal(global);
+	global.rgb_enables &= ~(PISP_BE_RGB_ENABLE_OUTPUT0 + PISP_BE_RGB_ENABLE_OUTPUT1);
+	global.rgb_enables |= beEnables;
+	be_->SetGlobal(global);
+
+	beEnabled_ = beEnables & (PISP_BE_RGB_ENABLE_OUTPUT0 | PISP_BE_RGB_ENABLE_OUTPUT1);
+
+	/* CFE statistics output format. */
+	format = {};
+	format.fourcc = V4L2PixelFormat(V4L2_META_FMT_RPI_FE_STATS);
+	ret = cfe_[Cfe::Stats].dev()->setFormat(&format);
+	if (ret) {
+		LOG(RPI, Error) << "Failed to set format on CFE stats stream: "
+				<< format.toString();
+		return ret;
+	}
+
+	/* CFE config format. */
+	format = {};
+	format.fourcc = V4L2PixelFormat(V4L2_META_FMT_RPI_FE_CFG);
+	ret = cfe_[Cfe::Config].dev()->setFormat(&format);
+	if (ret) {
+		LOG(RPI, Error) << "Failed to set format on CFE config stream: "
+				<< format.toString();
+		return ret;
+	}
+
+	/*
+	 * Configure the CFE embedded data output format only if the sensor
+	 * supports it.
+	 */
+	V4L2SubdeviceFormat embeddedFormat;
+	if (sensorMetadata_) {
+		sensor_->device()->getFormat(1, &embeddedFormat);
+		format = {};
+		format.fourcc = V4L2PixelFormat(V4L2_META_FMT_SENSOR_DATA);
+		format.planes[0].size = embeddedFormat.size.width * embeddedFormat.size.height;
+
+		LOG(RPI, Debug) << "Setting embedded data format " << format.toString();
+		ret = cfe_[Cfe::Embedded].dev()->setFormat(&format);
+		if (ret) {
+			LOG(RPI, Error) << "Failed to set format on CFE embedded: "
+					<< format;
+			return ret;
+		}
+	}
+
+	/* Set smallest selection the ISP will allow. */
+	ispMinCropSize_ = Size(32, 32);
+
+	if (!outStreams.empty()) {
+		/* Adjust aspect ratio by providing crops on the input image. */
+		Size size = cfeFormat.size.boundedToAspectRatio(outStreams[0].cfg->size);
+		ispCrop_ = size.centeredTo(Rectangle(cfeFormat.size).center());
+
+		/*
+		 * Calculate the minimum crop. The rule is that (output_dim - 1) / (input_dim - 1)
+		 * must be strictly < 16. We add 2 after dividing because +1
+		 * comes from the division that rounds down, and +1 because we
+		 * had (input_dim - 1).
+		 */
+		Size scalingMinSize = outStreams[0].cfg->size.shrunkBy({ 1, 1 }) / 16;
+		scalingMinSize.growBy({ 2, 2 });
+		ispMinCropSize_.expandTo(scalingMinSize);
+	}
+
+	configureEntities(rpiConfig->sensorFormat_, embeddedFormat);
+	configureCfe();
+
+	if (beEnabled_)
+		configureBe(rpiConfig->yuvColorSpace_);
+
+	platformSetIspCrop();
+
+	return 0;
+}
+
+void PiSPCameraData::platformStart()
+{
+	/*
+	 * We don't need to worry about dequeue events for the TDN and Stitch
+	 * nodes as the buffers are simply ping-ponged every frame. But we do
+	 * want to track the currently used input index.
+	 */
+	tdnInputIndex_ = 0;
+	stitchInputIndex_ = 0;
+
+	cfeJobQueue_ = {};
+
+	for (unsigned int i = 0; i < config_.numCfeConfigQueue; i++)
+		prepareCfe();
+
+	/* Clear the debug dump file history. */
+	last_dump_file_.clear();
+}
+
+void PiSPCameraData::platformStop()
+{
+	cfeJobQueue_ = {};
+}
+
+void PiSPCameraData::platformFreeBuffers()
+{
+	tdnBuffers_.clear();
+	stitchBuffers_.clear();
+}
+
+void PiSPCameraData::cfeBufferDequeue(FrameBuffer *buffer)
+{
+	RPi::Stream *stream = nullptr;
+	int index;
+
+	if (!isRunning())
+		return;
+
+	for (RPi::Stream &s : cfe_) {
+		index = s.getBufferId(buffer);
+		if (index) {
+			stream = &s;
+			break;
+		}
+	}
+
+	/* If the last CFE job has completed, we need a new job entry in the queue. */
+	if (cfeJobQueue_.empty() || cfeJobComplete())
+		cfeJobQueue_.push({});
+
+	CfeJob &job = cfeJobQueue_.back();
+
+	/* The buffer must belong to one of our streams. */
+	ASSERT(stream);
+
+	LOG(RPI, Debug) << "Stream " << stream->name() << " buffer dequeue"
+			<< ", buffer id " << index
+			<< ", timestamp: " << buffer->metadata().timestamp;
+
+	job.buffers[stream] = buffer;
+
+	if (stream == &cfe_[Cfe::Output0]) {
+		/*
+		 * Lookup the sensor controls used for this frame sequence from
+		 * DelayedControl and queue them along with the frame buffer.
+		 */
+		auto [ctrl, delayContext] = delayedCtrls_->get(buffer->metadata().sequence);
+		/*
+		 * Add the frame timestamp to the ControlList for the IPA to use
+		 * as it does not receive the FrameBuffer object.
+		 */
+		ctrl.set(controls::SensorTimestamp, buffer->metadata().timestamp);
+		job.sensorControls = std::move(ctrl);
+		job.delayContext = delayContext;
+	} else if (stream == &cfe_[Cfe::Config]) {
+		/* The config buffer can be re-queued back straight away. */
+		handleStreamBuffer(buffer, &cfe_[Cfe::Config]);
+		prepareCfe();
+	}
+
+	handleState();
+}
+
+void PiSPCameraData::beInputDequeue(FrameBuffer *buffer)
+{
+	if (!isRunning())
+		return;
+
+	LOG(RPI, Debug) << "Stream ISP Input buffer complete"
+			<< ", buffer id " << cfe_[Cfe::Output0].getBufferId(buffer)
+			<< ", timestamp: " << buffer->metadata().timestamp;
+
+	/* The ISP input buffer gets re-queued into CFE. */
+	handleStreamBuffer(buffer, &cfe_[Cfe::Output0]);
+	handleState();
+}
+
+void PiSPCameraData::beOutputDequeue(FrameBuffer *buffer)
+{
+	RPi::Stream *stream = nullptr;
+	int index;
+
+	if (!isRunning())
+		return;
+
+	for (RPi::Stream &s : isp_) {
+		index = s.getBufferId(buffer);
+		if (index) {
+			stream = &s;
+			break;
+		}
+	}
+
+	/* The buffer must belong to one of our ISP output streams. */
+	ASSERT(stream);
+
+	LOG(RPI, Debug) << "Stream " << stream->name() << " buffer complete"
+			<< ", buffer id " << index
+			<< ", timestamp: " << buffer->metadata().timestamp;
+
+	bool downscale = stream->swDownscale() > 1;
+	bool needs32bitConv = !!(stream->getFlags() & StreamFlag::Needs32bitConv);
+
+	if (downscale || needs32bitConv)
+		dmabufSyncStart(buffer->planes()[0].fd);
+
+	if (downscale) {
+		/* Further software downscaling must be applied. */
+		downscaleStreamBuffer(stream, index);
+	}
+
+	/* Convert 24bpp outputs to 32bpp outputs where necessary. */
+	if (needs32bitConv) {
+		unsigned int stride = stream->configuration().stride;
+		unsigned int width = stream->configuration().size.width;
+		unsigned int height = stream->configuration().size.height;
+
+		const RPi::BufferObject &b = stream->getBuffer(index);
+
+		ASSERT(b.mapped);
+		void *mem = b.mapped->planes()[0].data();
+		do32BitConversion(mem, width, height, stride);
+	}
+
+	if (downscale || needs32bitConv)
+		dmabufSyncEnd(buffer->planes()[0].fd);
+
+	handleStreamBuffer(buffer, stream);
+
+	/*
+	 * Increment the number of ISP outputs generated.
+	 * This is needed to track dropped frames.
+	 */
+	ispOutputCount_++;
+	handleState();
+}
+
+void PiSPCameraData::processStatsComplete(const ipa::RPi::BufferIds &buffers)
+{
+	if (!isRunning())
+		return;
+
+	handleStreamBuffer(cfe_[Cfe::Stats].getBuffers().at(buffers.stats & RPi::MaskID).buffer,
+			   &cfe_[Cfe::Stats]);
+}
+
+void PiSPCameraData::setCameraTimeout(uint32_t maxFrameLengthMs)
+{
+	/*
+	 * Set the dequeue timeout to the larger of 5x the maximum reported
+	 * frame length advertised by the IPA over a number of frames. Allow
+	 * a minimum timeout value of 1s.
+	 */
+	utils::Duration timeout =
+		std::max<utils::Duration>(1s, 5 * maxFrameLengthMs * 1ms);
+
+	LOG(RPI, Debug) << "Setting CFE timeout to " << timeout;
+	cfe_[Cfe::Output0].dev()->setDequeueTimeout(timeout);
+}
+
+void PiSPCameraData::prepareIspComplete(const ipa::RPi::BufferIds &buffers, bool stitchSwapBuffers)
+{
+	unsigned int embeddedId = buffers.embedded & RPi::MaskID;
+	unsigned int bayerId = buffers.bayer & RPi::MaskID;
+	FrameBuffer *buffer;
+
+	if (!isRunning())
+		return;
+
+	if (sensorMetadata_ && embeddedId) {
+		buffer = cfe_[Cfe::Embedded].getBuffers().at(embeddedId).buffer;
+		handleStreamBuffer(buffer, &cfe_[Cfe::Embedded]);
+	}
+
+	if (!beEnabled_) {
+		/*
+		 * If there is no need to run the Backend, just signal that the
+		 * input buffer is completed and all Backend outputs are ready.
+		 */
+		ispOutputCount_ = ispOutputTotal_;
+		buffer = cfe_[Cfe::Output0].getBuffers().at(bayerId).buffer;
+		handleStreamBuffer(buffer, &cfe_[Cfe::Output0]);
+	} else
+		prepareBe(bayerId, stitchSwapBuffers);
+
+	state_ = State::IpaComplete;
+	handleState();
+}
+
+int PiSPCameraData::configureCfe()
+{
+	V4L2DeviceFormat cfeFormat;
+	cfe_[Cfe::Output0].dev()->getFormat(&cfeFormat);
+
+	std::scoped_lock<FrontEnd> l(*fe_);
+
+	pisp_fe_global_config global;
+	fe_->GetGlobal(global);
+	global.enables &= ~PISP_FE_ENABLE_COMPRESS0;
+
+	global.enables |= PISP_FE_ENABLE_OUTPUT0;
+	global.bayer_order = toPiSPBayerOrder(cfeFormat.fourcc);
+
+	pisp_image_format_config image = toPiSPImageFormat(cfeFormat);
+	pisp_fe_input_config input = {};
+
+	input.streaming = 1;
+	input.format = image;
+	input.format.format = PISP_IMAGE_FORMAT_BPS_16;
+
+	if (PISP_IMAGE_FORMAT_compressed(image.format)) {
+		pisp_compress_config compress;
+		compress.offset = DefaultCompressionOffset;
+		compress.mode =	(image.format & PISP_IMAGE_FORMAT_COMPRESSION_MASK) /
+					PISP_IMAGE_FORMAT_COMPRESSION_MODE_1;
+		global.enables |= PISP_FE_ENABLE_COMPRESS0;
+		fe_->SetCompress(0, compress);
+	}
+
+	if (input.format.width > pispVariant_.FrontEndDownscalerMaxWidth(0, 0))
+		global.enables |= PISP_FE_ENABLE_DECIMATE;
+
+	fe_->SetGlobal(global);
+	fe_->SetInput(input);
+	fe_->SetOutputFormat(0, image);
+
+	return 0;
+}
+
+bool PiSPCameraData::calculateCscConfiguration(const V4L2DeviceFormat &v4l2Format, pisp_be_ccm_config &csc)
+{
+	const PixelFormat &pixFormat = v4l2Format.fourcc.toPixelFormat();
+	const PixelFormatInfo &info = PixelFormatInfo::info(pixFormat);
+	memset(&csc, 0, sizeof(csc));
+
+	if (info.colourEncoding == PixelFormatInfo::ColourEncodingYUV) {
+		/* Look up the correct YCbCr conversion matrix for this colour space. */
+		if (v4l2Format.colorSpace == ColorSpace::Sycc)
+			be_->InitialiseYcbcr(csc, "jpeg");
+		else if (v4l2Format.colorSpace == ColorSpace::Smpte170m)
+			be_->InitialiseYcbcr(csc, "smpte170m");
+		else if (v4l2Format.colorSpace == ColorSpace::Rec709)
+			be_->InitialiseYcbcr(csc, "rec709");
+		else {
+			LOG(RPI, Warning)
+				<< "Unrecognised colour space "
+				<< ColorSpace::toString(v4l2Format.colorSpace)
+				<< ", defaulting to sYCC";
+			be_->InitialiseYcbcr(csc, "jpeg");
+		}
+		return true;
+	}
+	/* There will be more formats to check for in due course. */
+	else if (pixFormat == formats::RGB888) {
+		/* Identity matrix but with RB colour swap. */
+		csc.coeffs[2] = csc.coeffs[4] = csc.coeffs[6] = 1 << 10;
+		return true;
+	}
+
+	return false;
+}
+
+int PiSPCameraData::configureBe(const std::optional<ColorSpace> &yuvColorSpace)
+{
+	pisp_image_format_config inputFormat;
+	V4L2DeviceFormat cfeFormat;
+
+	isp_[Isp::Input].dev()->getFormat(&cfeFormat);
+	inputFormat = toPiSPImageFormat(cfeFormat);
+
+	pisp_be_global_config global;
+	be_->GetGlobal(global);
+	global.bayer_enables &= ~(PISP_BE_BAYER_ENABLE_DECOMPRESS +
+				  PISP_BE_BAYER_ENABLE_TDN_DECOMPRESS +
+				  PISP_BE_BAYER_ENABLE_TDN_COMPRESS +
+				  PISP_BE_BAYER_ENABLE_STITCH_DECOMPRESS +
+				  PISP_BE_BAYER_ENABLE_STITCH_COMPRESS);
+	global.rgb_enables &= ~(PISP_BE_RGB_ENABLE_RESAMPLE0 +
+				PISP_BE_RGB_ENABLE_RESAMPLE1 +
+				PISP_BE_RGB_ENABLE_DOWNSCALE0 +
+				PISP_BE_RGB_ENABLE_DOWNSCALE1 +
+				PISP_BE_RGB_ENABLE_CSC0 +
+				PISP_BE_RGB_ENABLE_CSC1);
+
+	global.bayer_enables |= PISP_BE_BAYER_ENABLE_INPUT;
+	global.bayer_order = toPiSPBayerOrder(cfeFormat.fourcc);
+
+	ispOutputTotal_ = 1; /* Config buffer */
+	if (PISP_IMAGE_FORMAT_compressed(inputFormat.format)) {
+		pisp_decompress_config decompress;
+		decompress.offset = DefaultCompressionOffset;
+		decompress.mode = (inputFormat.format & PISP_IMAGE_FORMAT_COMPRESSION_MASK)
+					/ PISP_IMAGE_FORMAT_COMPRESSION_MODE_1;
+		global.bayer_enables |= PISP_BE_BAYER_ENABLE_DECOMPRESS;
+		be_->SetDecompress(decompress);
+	}
+
+	if (global.rgb_enables & PISP_BE_RGB_ENABLE_OUTPUT0) {
+		pisp_be_output_format_config outputFormat0 = {};
+		V4L2DeviceFormat ispFormat0 = {};
+
+		isp_[Isp::Output0].dev()->getFormat(&ispFormat0);
+		outputFormat0.image = toPiSPImageFormat(ispFormat0);
+
+		pisp_be_ccm_config csc;
+		if (calculateCscConfiguration(ispFormat0, csc)) {
+			global.rgb_enables |= PISP_BE_RGB_ENABLE_CSC0;
+			be_->SetCsc(0, csc);
+		}
+
+		BackEnd::SmartResize resize = {};
+		resize.width = ispFormat0.size.width;
+		resize.height = ispFormat0.size.height;
+		be_->SetSmartResize(0, resize);
+
+		setupOutputClipping(ispFormat0, outputFormat0);
+
+		be_->SetOutputFormat(0, outputFormat0);
+		ispOutputTotal_++;
+	}
+
+	if (global.rgb_enables & PISP_BE_RGB_ENABLE_OUTPUT1) {
+		pisp_be_output_format_config outputFormat1 = {};
+		V4L2DeviceFormat ispFormat1 = {};
+
+		isp_[Isp::Output1].dev()->getFormat(&ispFormat1);
+		outputFormat1.image = toPiSPImageFormat(ispFormat1);
+
+		pisp_be_ccm_config csc;
+		if (calculateCscConfiguration(ispFormat1, csc)) {
+			global.rgb_enables |= PISP_BE_RGB_ENABLE_CSC1;
+			be_->SetCsc(1, csc);
+		}
+
+		BackEnd::SmartResize resize = {};
+		resize.width = ispFormat1.size.width;
+		resize.height = ispFormat1.size.height;
+		be_->SetSmartResize(1, resize);
+
+		setupOutputClipping(ispFormat1, outputFormat1);
+
+		be_->SetOutputFormat(1, outputFormat1);
+		ispOutputTotal_++;
+	}
+
+	/* Setup the TDN I/O blocks in case TDN gets turned on later. */
+	V4L2DeviceFormat tdnV4L2Format;
+	isp_[Isp::TdnOutput].dev()->getFormat(&tdnV4L2Format);
+	pisp_image_format_config tdnFormat = toPiSPImageFormat(tdnV4L2Format);
+	be_->SetTdnOutputFormat(tdnFormat);
+	be_->SetTdnInputFormat(tdnFormat);
+
+	if (PISP_IMAGE_FORMAT_compressed(tdnFormat.format)) {
+		pisp_decompress_config tdnDecompress;
+		pisp_compress_config tdnCompress;
+
+		tdnDecompress.offset = tdnCompress.offset = DefaultCompressionOffset;
+		tdnDecompress.mode = tdnCompress.mode = DefaultCompressionMode;
+		be_->SetTdnDecompress(tdnDecompress);
+		be_->SetTdnCompress(tdnCompress);
+		global.bayer_enables |= PISP_BE_BAYER_ENABLE_TDN_DECOMPRESS +
+					PISP_BE_BAYER_ENABLE_TDN_COMPRESS;
+	}
+
+	/* Likewise for the Stitch block. */
+	V4L2DeviceFormat stitchV4L2Format;
+	isp_[Isp::StitchOutput].dev()->getFormat(&stitchV4L2Format);
+	pisp_image_format_config stitchFormat = toPiSPImageFormat(stitchV4L2Format);
+	be_->SetStitchOutputFormat(stitchFormat);
+	be_->SetStitchInputFormat(stitchFormat);
+
+	if (PISP_IMAGE_FORMAT_compressed(stitchFormat.format)) {
+		pisp_decompress_config stitchDecompress;
+		pisp_compress_config stitchCompress;
+
+		/* Stitch block is after BLC, so compression offset should be 0. */
+		stitchDecompress.offset = stitchCompress.offset = 0;
+		stitchDecompress.mode = stitchCompress.mode = DefaultCompressionMode;
+		be_->SetStitchDecompress(stitchDecompress);
+		be_->SetStitchCompress(stitchCompress);
+		global.bayer_enables |= PISP_BE_BAYER_ENABLE_STITCH_DECOMPRESS +
+					PISP_BE_BAYER_ENABLE_STITCH_COMPRESS;
+	}
+
+	/*
+	 * For the bit of the pipeline where we go temporarily into YCbCr, we'll use the
+	 * same flavour of YCbCr as dictated by the headline colour space. But there's
+	 * no benefit from compressing and shifting the range, so we'll stick with the
+	 * full range version of whatever that colour space is.
+	 */
+	if (yuvColorSpace) {
+		pisp_be_ccm_config ccm;
+		if (yuvColorSpace == ColorSpace::Sycc) {
+			be_->InitialiseYcbcr(ccm, "jpeg");
+			be_->SetYcbcr(ccm);
+			be_->InitialiseYcbcrInverse(ccm, "jpeg");
+			be_->SetYcbcrInverse(ccm);
+		} else if (yuvColorSpace == ColorSpace::Smpte170m) {
+			/* We want the full range version of smpte170m, aka. jpeg */
+			be_->InitialiseYcbcr(ccm, "jpeg");
+			be_->SetYcbcr(ccm);
+			be_->InitialiseYcbcrInverse(ccm, "jpeg");
+			be_->SetYcbcrInverse(ccm);
+		} else if (yuvColorSpace == ColorSpace::Rec709) {
+			be_->InitialiseYcbcr(ccm, "rec709_full");
+			be_->SetYcbcr(ccm);
+			be_->InitialiseYcbcrInverse(ccm, "rec709_full");
+			be_->SetYcbcrInverse(ccm);
+		} else {
+			/* Validation should have ensured this can't happen. */
+			LOG(RPI, Error)
+				<< "Invalid colour space "
+				<< ColorSpace::toString(yuvColorSpace);
+			ASSERT(0);
+		}
+	} else {
+		/* Again, validation should have prevented this. */
+		LOG(RPI, Error) << "No YUV colour space";
+		ASSERT(0);
+	}
+
+	be_->SetGlobal(global);
+	be_->SetInputFormat(inputFormat);
+
+	return 0;
+}
+
+void PiSPCameraData::platformSetIspCrop()
+{
+	pisp_be_crop_config beCrop = {
+		static_cast<uint16_t>(ispCrop_.x),
+		static_cast<uint16_t>(ispCrop_.y),
+		static_cast<uint16_t>(ispCrop_.width),
+		static_cast<uint16_t>(ispCrop_.height)
+	};
+
+	be_->SetCrop(beCrop);
+}
+
+int PiSPCameraData::platformInitIpa(ipa::RPi::InitParams &params)
+{
+	params.fe = fe_.fd();
+	params.be = be_.fd();
+	return 0;
+}
+
+int PiSPCameraData::configureEntities(V4L2SubdeviceFormat sensorFormat,
+				      V4L2SubdeviceFormat &embeddedFormat)
+{
+	int ret = 0;
+
+	constexpr unsigned int csiVideoSinkPad = 0;
+	constexpr unsigned int csiMetaSinkPad = 1;
+	constexpr unsigned int csiVideoSourcePad = 4;
+	constexpr unsigned int csiMetaSourcePad = 5;
+
+	constexpr unsigned int feVideoSinkPad = 0;
+	constexpr unsigned int feConfigSinkPad = 1;
+	constexpr unsigned int feVideo0SourcePad = 2;
+	constexpr unsigned int feVideo1SourcePad = 3;
+	constexpr unsigned int feStatsSourcePad = 4;
+
+	const MediaEntity *csi2 = csi2Subdev_->entity();
+	const MediaEntity *fe = feSubdev_->entity();
+
+	for (MediaLink *link : csi2->pads()[csiVideoSourcePad]->links()) {
+		if (link->sink()->entity()->name() == "rp1-cfe-csi2_ch0")
+			link->setEnabled(false);
+		else if (link->sink()->entity()->name() == "pisp-fe")
+			link->setEnabled(true);
+	}
+
+	csi2->pads()[csiMetaSourcePad]->links()[0]->setEnabled(sensorMetadata_);
+
+	fe->pads()[feConfigSinkPad]->links()[0]->setEnabled(true);
+	fe->pads()[feVideo0SourcePad]->links()[0]->setEnabled(true);
+	fe->pads()[feVideo1SourcePad]->links()[0]->setEnabled(false);
+	fe->pads()[feStatsSourcePad]->links()[0]->setEnabled(true);
+
+	ret = csi2Subdev_->setFormat(csiVideoSinkPad, &sensorFormat);
+	if (ret)
+		return ret;
+
+	if (sensorMetadata_) {
+		ret = csi2Subdev_->setFormat(csiMetaSinkPad, &embeddedFormat);
+		if (ret)
+			return ret;
+
+		ret = csi2Subdev_->setFormat(csiMetaSourcePad, &embeddedFormat);
+		if (ret)
+			return ret;
+	}
+
+	V4L2SubdeviceFormat feFormat = sensorFormat;
+	feFormat.mbus_code = mbusCodeUnpacked16(sensorFormat.mbus_code);
+	ret = feSubdev_->setFormat(feVideoSinkPad, &feFormat);
+	if (ret)
+		return ret;
+
+	ret = csi2Subdev_->setFormat(csiVideoSourcePad, &feFormat);
+	if (ret)
+		return ret;
+
+	V4L2DeviceFormat feOutputFormat;
+	cfe_[Cfe::Output0].dev()->getFormat(&feOutputFormat);
+	BayerFormat feOutputBayer = BayerFormat::fromV4L2PixelFormat(feOutputFormat.fourcc);
+
+	feFormat.mbus_code = bayerToMbusCode(feOutputBayer);
+	ret = feSubdev_->setFormat(feVideo0SourcePad, &feFormat);
+
+	return ret;
+}
+
+void PiSPCameraData::prepareCfe()
+{
+	/* Fetch an unused config buffer from the stream .*/
+	const RPi::BufferObject &config = cfe_[Cfe::Config].acquireBuffer();
+	ASSERT(config.mapped);
+
+	{
+		std::scoped_lock<FrontEnd> l(*fe_);
+		Span<uint8_t> configBuffer = config.mapped->planes()[0];
+		fe_->Prepare(reinterpret_cast<pisp_fe_config *>(configBuffer.data()));
+	}
+
+	config.buffer->_d()->metadata().planes()[0].bytesused = sizeof(pisp_fe_config);
+	cfe_[Cfe::Config].queueBuffer(config.buffer);
+}
+
+void PiSPCameraData::prepareBe(uint32_t bufferId, bool stitchSwapBuffers)
+{
+	ispOutputCount_ = 0;
+
+	FrameBuffer *buffer = cfe_[Cfe::Output0].getBuffers().at(bufferId).buffer;
+
+	LOG(RPI, Debug) << "Input re-queue to ISP, buffer id " << bufferId
+			<< ", timestamp: " << buffer->metadata().timestamp;
+
+	isp_[Isp::Input].queueBuffer(buffer);
+
+	/* Ping-pong between input/output buffers for the TDN and Stitch nodes. */
+	if (!config_.disableTdn) {
+		isp_[Isp::TdnInput].queueBuffer(tdnBuffers_[tdnInputIndex_]);
+		isp_[Isp::TdnOutput].queueBuffer(tdnBuffers_[tdnInputIndex_ ^ 1]);
+		tdnInputIndex_ ^= 1;
+	}
+
+	if (!config_.disableHdr) {
+		if (stitchSwapBuffers)
+			stitchInputIndex_ ^= 1;
+		isp_[Isp::StitchInput].queueBuffer(stitchBuffers_[stitchInputIndex_]);
+		isp_[Isp::StitchOutput].queueBuffer(stitchBuffers_[stitchInputIndex_ ^ 1]);
+	}
+
+	/* Fetch an unused config buffer from the stream .*/
+	const RPi::BufferObject &config = isp_[Isp::Config].acquireBuffer();
+	ASSERT(config.mapped);
+
+	Span<uint8_t> configBufferSpan = config.mapped->planes()[0];
+	pisp_be_tiles_config *configBuffer = reinterpret_cast<pisp_be_tiles_config *>(configBufferSpan.data());
+	be_->Prepare(configBuffer);
+
+	/*
+	 * If the LIBCAMERA_RPI_PISP_CONFIG_DUMP environment variable is set,
+	 * dump the Backend config to the given file. This is a one-shot
+	 * operation, so log the filename that was provided and allow the
+	 * application to change the filename for multiple dumps in a single
+	 * run.
+	 *
+	 * \todo Using an environment variable is only a temporary solution
+	 * until we have support for vendor specific controls in libcamera.
+	 */
+	const char *config_dump = utils::secure_getenv("LIBCAMERA_RPI_PISP_CONFIG_DUMP");
+	if (config_dump && last_dump_file_ != config_dump) {
+		std::ofstream of(config_dump);
+		if (of.is_open()) {
+			of << be_->GetJsonConfig(configBuffer);
+			last_dump_file_ = config_dump;
+		}
+	}
+
+	isp_[Isp::Config].queueBuffer(config.buffer);
+}
+
+void PiSPCameraData::tryRunPipeline()
+{
+	/* If any of our request or buffer queues are empty, we cannot proceed. */
+	if (state_ != State::Idle || requestQueue_.empty() || !cfeJobComplete())
+		return;
+
+	CfeJob &job = cfeJobQueue_.front();
+
+	/* Take the first request from the queue and action the IPA. */
+	Request *request = requestQueue_.front();
+
+	/* See if a new ScalerCrop value needs to be applied. */
+	applyScalerCrop(request->controls());
+
+	/*
+	 * Clear the request metadata and fill it with some initial non-IPA
+	 * related controls. We clear it first because the request metadata
+	 * may have been populated if we have dropped the previous frame.
+	 */
+	request->metadata().clear();
+	fillRequestMetadata(job.sensorControls, request);
+
+	/* Set our state to say the pipeline is active. */
+	state_ = State::Busy;
+
+	unsigned int bayerId = cfe_[Cfe::Output0].getBufferId(job.buffers[&cfe_[Cfe::Output0]]);
+	unsigned int statsId = cfe_[Cfe::Stats].getBufferId(job.buffers[&cfe_[Cfe::Stats]]);
+	ASSERT(bayerId && statsId);
+
+	std::stringstream ss;
+	ss << "Signalling IPA processStats and prepareIsp:"
+	   << " Bayer buffer id: " << bayerId
+	   << " Stats buffer id: " << statsId;
+
+	ipa::RPi::PrepareParams params;
+	params.buffers.bayer = RPi::MaskBayerData | bayerId;
+	params.buffers.stats = RPi::MaskStats | statsId;
+	params.ipaContext = requestQueue_.front()->sequence();
+	params.delayContext = job.delayContext;
+	params.sensorControls = std::move(job.sensorControls);
+	params.requestControls = request->controls();
+
+	if (sensorMetadata_) {
+		unsigned int embeddedId =
+			cfe_[Cfe::Embedded].getBufferId(job.buffers[&cfe_[Cfe::Embedded]]);
+
+		ASSERT(embeddedId);
+		params.buffers.embedded = RPi::MaskEmbeddedData | embeddedId;
+		ss << " Embedded buffer id: " << embeddedId;
+	}
+
+	LOG(RPI, Debug) << ss.str();
+
+	cfeJobQueue_.pop();
+	ipa_->prepareIsp(params);
+}
+
+REGISTER_PIPELINE_HANDLER(PipelineHandlerPiSP)
+
+} /* namespace libcamera */