linux/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.txt
Matthias Brugger f5e489e6ee dt-bindings: mediatek: Add bindig for MT7623 IOMMU and SMI
This patch add the binding documentation for the iommu and smi
devices on the MT7623 SoC.

Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
2018-10-05 10:11:33 +02:00

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SMI (Smart Multimedia Interface) Common
The hardware block diagram please check bindings/iommu/mediatek,iommu.txt
Mediatek SMI have two generations of HW architecture, mt2712 and mt8173 use
the second generation of SMI HW while mt2701 uses the first generation HW of
SMI.
There's slight differences between the two SMI, for generation 2, the
register which control the iommu port is at each larb's register base. But
for generation 1, the register is at smi ao base(smi always on register
base). Besides that, the smi async clock should be prepared and enabled for
SMI generation 1 to transform the smi clock into emi clock domain, but that is
not needed for SMI generation 2.
Required properties:
- compatible : must be one of :
"mediatek,mt2701-smi-common"
"mediatek,mt2712-smi-common"
"mediatek,mt7623-smi-common", "mediatek,mt2701-smi-common"
"mediatek,mt8173-smi-common"
- reg : the register and size of the SMI block.
- power-domains : a phandle to the power domain of this local arbiter.
- clocks : Must contain an entry for each entry in clock-names.
- clock-names : must contain 3 entries for generation 1 smi HW and 2 entries
for generation 2 smi HW as follows:
- "apb" : Advanced Peripheral Bus clock, It's the clock for setting
the register.
- "smi" : It's the clock for transfer data and command.
They may be the same if both source clocks are the same.
- "async" : asynchronous clock, it help transform the smi clock into the emi
clock domain, this clock is only needed by generation 1 smi HW.
Example:
smi_common: smi@14022000 {
compatible = "mediatek,mt8173-smi-common";
reg = <0 0x14022000 0 0x1000>;
power-domains = <&scpsys MT8173_POWER_DOMAIN_MM>;
clocks = <&mmsys CLK_MM_SMI_COMMON>,
<&mmsys CLK_MM_SMI_COMMON>;
clock-names = "apb", "smi";
};