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author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-19 13:14:34 -0700 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-19 13:14:34 -0700 |
commit | f7a0fd56e4f58aec3300082fc10433052e2f1863 (patch) | |
tree | 4b3348f4866f6b3417f456a298229d63d4581424 /Documentation/devicetree | |
parent | 5e1e704a7de14ae79dc4d983dbbcab67064960c9 (diff) | |
parent | 31d141e3a666269a3b6fcccddb0351caf7454240 (diff) | |
download | linux-f7a0fd56e4f58aec3300082fc10433052e2f1863.tar.bz2 |
Merge 3.12-rc6 into staging-next.
We want these fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r-- | Documentation/devicetree/bindings/memory.txt | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/Documentation/devicetree/bindings/memory.txt b/Documentation/devicetree/bindings/memory.txt deleted file mode 100644 index eb2469365593..000000000000 --- a/Documentation/devicetree/bindings/memory.txt +++ /dev/null @@ -1,168 +0,0 @@ -*** Memory binding *** - -The /memory node provides basic information about the address and size -of the physical memory. This node is usually filled or updated by the -bootloader, depending on the actual memory configuration of the given -hardware. - -The memory layout is described by the following node: - -/ { - #address-cells = <(n)>; - #size-cells = <(m)>; - memory { - device_type = "memory"; - reg = <(baseaddr1) (size1) - (baseaddr2) (size2) - ... - (baseaddrN) (sizeN)>; - }; - ... -}; - -A memory node follows the typical device tree rules for "reg" property: -n: number of cells used to store base address value -m: number of cells used to store size value -baseaddrX: defines a base address of the defined memory bank -sizeX: the size of the defined memory bank - - -More than one memory bank can be defined. - - -*** Reserved memory regions *** - -In /memory/reserved-memory node one can create child nodes describing -particular reserved (excluded from normal use) memory regions. Such -memory regions are usually designed for the special usage by various -device drivers. A good example are contiguous memory allocations or -memory sharing with other operating system on the same hardware board. -Those special memory regions might depend on the board configuration and -devices used on the target system. - -Parameters for each memory region can be encoded into the device tree -with the following convention: - -[(label):] (name) { - compatible = "linux,contiguous-memory-region", "reserved-memory-region"; - reg = <(address) (size)>; - (linux,default-contiguous-region); -}; - -compatible: one or more of: - - "linux,contiguous-memory-region" - enables binding of this - region to Contiguous Memory Allocator (special region for - contiguous memory allocations, shared with movable system - memory, Linux kernel-specific). - - "reserved-memory-region" - compatibility is defined, given - region is assigned for exclusive usage for by the respective - devices. - -reg: standard property defining the base address and size of - the memory region - -linux,default-contiguous-region: property indicating that the region - is the default region for all contiguous memory - allocations, Linux specific (optional) - -It is optional to specify the base address, so if one wants to use -autoconfiguration of the base address, '0' can be specified as a base -address in the 'reg' property. - -The /memory/reserved-memory node must contain the same #address-cells -and #size-cells value as the root node. - - -*** Device node's properties *** - -Once regions in the /memory/reserved-memory node have been defined, they -may be referenced by other device nodes. Bindings that wish to reference -memory regions should explicitly document their use of the following -property: - -memory-region = <&phandle_to_defined_region>; - -This property indicates that the device driver should use the memory -region pointed by the given phandle. - - -*** Example *** - -This example defines a memory consisting of 4 memory banks. 3 contiguous -regions are defined for Linux kernel, one default of all device drivers -(named contig_mem, placed at 0x72000000, 64MiB), one dedicated to the -framebuffer device (labelled display_mem, placed at 0x78000000, 8MiB) -and one for multimedia processing (labelled multimedia_mem, placed at -0x77000000, 64MiB). 'display_mem' region is then assigned to fb@12300000 -device for DMA memory allocations (Linux kernel drivers will use CMA is -available or dma-exclusive usage otherwise). 'multimedia_mem' is -assigned to scaler@12500000 and codec@12600000 devices for contiguous -memory allocations when CMA driver is enabled. - -The reason for creating a separate region for framebuffer device is to -match the framebuffer base address to the one configured by bootloader, -so once Linux kernel drivers starts no glitches on the displayed boot -logo appears. Scaller and codec drivers should share the memory -allocations. - -/ { - #address-cells = <1>; - #size-cells = <1>; - - /* ... */ - - memory { - reg = <0x40000000 0x10000000 - 0x50000000 0x10000000 - 0x60000000 0x10000000 - 0x70000000 0x10000000>; - - reserved-memory { - #address-cells = <1>; - #size-cells = <1>; - - /* - * global autoconfigured region for contiguous allocations - * (used only with Contiguous Memory Allocator) - */ - contig_region@0 { - compatible = "linux,contiguous-memory-region"; - reg = <0x0 0x4000000>; - linux,default-contiguous-region; - }; - - /* - * special region for framebuffer - */ - display_region: region@78000000 { - compatible = "linux,contiguous-memory-region", "reserved-memory-region"; - reg = <0x78000000 0x800000>; - }; - - /* - * special region for multimedia processing devices - */ - multimedia_region: region@77000000 { - compatible = "linux,contiguous-memory-region"; - reg = <0x77000000 0x4000000>; - }; - }; - }; - - /* ... */ - - fb0: fb@12300000 { - status = "okay"; - memory-region = <&display_region>; - }; - - scaler: scaler@12500000 { - status = "okay"; - memory-region = <&multimedia_region>; - }; - - codec: codec@12600000 { - status = "okay"; - memory-region = <&multimedia_region>; - }; -}; |