linux/Documentation/devicetree/bindings/media/s5p-mfc.txt
Marek Szyprowski 60641e2259 [media] s5p-mfc: Use preallocated block allocator always for MFC v6+
It turned out that all versions of MFC v6+ hardware doesn't have a strict
requirement for ALL buffers to be allocated on higher addresses than the
firmware base like it was documented for MFC v5. This requirement is true
only for the device and per-context buffers. All video data buffers can be
allocated anywhere for all MFC v6+ versions. Basing on this fact, the
special DMA configuration based on two reserved memory regions is not
really needed for MFC v6+ devices, because the memory requirements for the
firmware, device and per-context buffers can be fulfilled by the simple
probe-time pre-allocated block allocator introduced in previous patch.

This patch enables support for such pre-allocated block based allocator
always for MFC v6+ devices. Due to the limitations of the memory management
subsystem the largest supported size of the pre-allocated buffer when no
CMA (Contiguous Memory Allocator) is enabled is 4 MiB.

This patch also removes the requirement to provide two reserved memory
regions for MFC v6+ devices in device tree. Now the driver is fully
functional without them.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Andrzej Hajda <a.hajda@samsung.com>
Tested-by: Smitha T Murthy <smitha.t@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-04-05 16:34:47 -03:00

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* Samsung Multi Format Codec (MFC)
Multi Format Codec (MFC) is the IP present in Samsung SoCs which
supports high resolution decoding and encoding functionalities.
The MFC device driver is a v4l2 driver which can encode/decode
video raw/elementary streams and has support for all popular
video codecs.
Required properties:
- compatible : value should be either one among the following
(a) "samsung,mfc-v5" for MFC v5 present in Exynos4 SoCs
(b) "samsung,mfc-v6" for MFC v6 present in Exynos5 SoCs
(c) "samsung,mfc-v7" for MFC v7 present in Exynos5420 SoC
(d) "samsung,mfc-v8" for MFC v8 present in Exynos5800 SoC
(e) "samsung,exynos5433-mfc" for MFC v8 present in Exynos5433 SoC
- reg : Physical base address of the IP registers and length of memory
mapped region.
- interrupts : MFC interrupt number to the CPU.
- clocks : from common clock binding: handle to mfc clock.
- clock-names : from common clock binding: must contain "mfc",
corresponding to entry in the clocks property.
Optional properties:
- power-domains : power-domain property defined with a phandle
to respective power domain.
- memory-region : from reserved memory binding: phandles to two reserved
memory regions, first is for "left" mfc memory bus interfaces,
second if for the "right" mfc memory bus, used when no SYSMMU
support is available; used only by MFC v5 present in Exynos4 SoCs
Obsolete properties:
- samsung,mfc-r, samsung,mfc-l : support removed, please use memory-region
property instead
Example:
SoC specific DT entry:
mfc: codec@13400000 {
compatible = "samsung,mfc-v5";
reg = <0x13400000 0x10000>;
interrupts = <0 94 0>;
power-domains = <&pd_mfc>;
clocks = <&clock 273>;
clock-names = "mfc";
};
Reserved memory specific DT entry for given board (see reserved memory binding
for more information):
reserved-memory {
#address-cells = <1>;
#size-cells = <1>;
ranges;
mfc_left: region@51000000 {
compatible = "shared-dma-pool";
no-map;
reg = <0x51000000 0x800000>;
};
mfc_right: region@43000000 {
compatible = "shared-dma-pool";
no-map;
reg = <0x43000000 0x800000>;
};
};
Board specific DT entry:
codec@13400000 {
memory-region = <&mfc_left>, <&mfc_right>;
};