libcamera: internal: Move dma_heaps.[h, cpp] to common directories

DmaHeap class is useful outside the RPi pipeline handler too.

Move dma_heaps.h and dma_heaps.cpp to common directories. Update
the build files and RPi vc4 pipeline handler accordingly.

Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> # sc8280xp Lenovo x13s
Tested-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/internal/dma_heaps.h

@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Raspberry Pi Ltd
+ *
+ * dma_heaps.h - Helper class for dma-heap allocations.
+ */
+
+#pragma once
+
+#include <stddef.h>
+
+#include <libcamera/base/unique_fd.h>
+
+namespace libcamera {
+
+class DmaHeap
+{
+public:
+	DmaHeap();
+	~DmaHeap();
+	bool isValid() const { return dmaHeapHandle_.isValid(); }
+	UniqueFD alloc(const char *name, std::size_t size);
+
+private:
+	UniqueFD dmaHeapHandle_;
+};
+
+} /* namespace libcamera */

include/libcamera/internal/meson.build

@@ -25,6 +25,7 @@ libcamera_internal_headers = files([
     'device_enumerator.h',
     'device_enumerator_sysfs.h',
     'device_enumerator_udev.h',
+    'dma_heaps.h',
     'formats.h',
     'framebuffer.h',
     'ipa_manager.h',