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ARC: [axs10x] Specify reserved memory for frame buffer 

Allocation of a frame buffer memory in a special memory region
allows bypassing of so-called IO Coherency aperture
which is typically set as a range 0x8z-0xAz.

I.e. all data traffic to PGU bypasses IO Coherency block
and saves its bandwidth for other peripherals.

Even though for AXS101 (which sorts ARC770 CPU) IOC is not
an option for a sake of keeping one DT description for the
base-board (axs10x_mb.dtsi) we're still defining reserved
memory location in the very end of DDR.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Cc: devicetree@vger.kernel.org
This commit is contained in:
Alexey Brodkin 2016-04-27 16:59:50 +03:00
parent 8aeab995fa
commit cb2ad5e533
4 changed files with 49 additions and 3 deletions
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22
arch/arc/boot/dts/axc001.dtsi
View File

@ -93,8 +93,26 @@
memory {
#address-cells = <1>;
#size-cells = <1>;
ranges = <0x00000000 0x80000000 0x40000000>;
ranges = <0x00000000 0x80000000 0x20000000>;
device_type = "memory";
reg = <0x80000000 0x20000000>; /* 512MiB */
reg = <0x80000000 0x1b000000>; /* (512 - 32) MiB */
};
reserved-memory {
#address-cells = <1>;
#size-cells = <1>;
ranges;
/*
* We just move frame buffer area to the very end of
* available DDR. And even though in case of ARC770 there's
* no strict requirement for a frame-buffer to be in any
* particular location it allows us to use the same
* base board's DT node for ARC PGU as for ARc HS38.
*/
frame_buffer: frame_buffer@9e000000 {
compatible = "shared-dma-pool";
reg = <0x9e000000 0x2000000>;
no-map;
};
};
};

14
arch/arc/boot/dts/axc003.dtsi
View File

@ -100,4 +100,18 @@
device_type = "memory";
reg = <0x80000000 0x20000000>; /* 512MiB */
};
reserved-memory {
#address-cells = <1>;
#size-cells = <1>;
ranges;
/*
* Move frame buffer out of IOC aperture (0x8z-0xAz).
*/
frame_buffer: frame_buffer@be000000 {
compatible = "shared-dma-pool";
reg = <0xbe000000 0x2000000>;
no-map;
};
};
};

14
arch/arc/boot/dts/axc003_idu.dtsi
View File

@ -123,4 +123,18 @@
device_type = "memory";
reg = <0x80000000 0x20000000>; /* 512MiB */
};
reserved-memory {
#address-cells = <1>;
#size-cells = <1>;
ranges;
/*
* Move frame buffer out of IOC aperture (0x8z-0xAz).
*/
frame_buffer: frame_buffer@be000000 {
compatible = "shared-dma-pool";
reg = <0xbe000000 0x2000000>;
no-map;
};
};
};

2
arch/arc/boot/dts/axs10x_mb.dtsi
View File

@ -283,7 +283,7 @@
encoder-slave = <&adv7511>;
clocks = <&pguclk>;
clock-names = "pxlclk";
memory-region = <&frame_buffer>;
port {
pgu_output: endpoint {
remote-endpoint = <&adv7511_input>;