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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml b/Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml new file mode 100644 index 000000000..af51b91c8 --- /dev/null +++ b/Documentation/devicetree/bindings/iommu/samsung,sysmmu.yaml @@ -0,0 +1,110 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iommu/samsung,sysmmu.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Samsung Exynos IOMMU H/W, System MMU (System Memory Management Unit) + +maintainers: + - Marek Szyprowski <m.szyprowski@samsung.com> + +description: |+ + Samsung's Exynos architecture contains System MMUs that enables scattered + physical memory chunks visible as a contiguous region to DMA-capable peripheral + devices like MFC, FIMC, FIMD, GScaler, FIMC-IS and so forth. + + System MMU is an IOMMU and supports identical translation table format to + ARMv7 translation tables with minimum set of page properties including access + permissions, shareability and security protection. In addition, System MMU has + another capabilities like L2 TLB or block-fetch buffers to minimize translation + latency. + + System MMUs are in many to one relation with peripheral devices, i.e. single + peripheral device might have multiple System MMUs (usually one for each bus + master), but one System MMU can handle transactions from only one peripheral + device. The relation between a System MMU and the peripheral device needs to be + defined in device node of the peripheral device. + + MFC in all Exynos SoCs and FIMD, M2M Scalers and G2D in Exynos5420 has 2 System + MMUs. + * MFC has one System MMU on its left and right bus. + * FIMD in Exynos5420 has one System MMU for window 0 and 4, the other system MMU + for window 1, 2 and 3. + * M2M Scalers and G2D in Exynos5420 has one System MMU on the read channel and + the other System MMU on the write channel. + + For information on assigning System MMU controller to its peripheral devices, + see generic IOMMU bindings. + +properties: + compatible: + const: samsung,exynos-sysmmu + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + + clocks: + minItems: 1 + maxItems: 2 + + clock-names: + oneOf: + - items: + - const: sysmmu + - items: + - const: sysmmu + - const: master + - items: + - const: aclk + - const: pclk + + "#iommu-cells": + const: 0 + + power-domains: + description: | + Required if the System MMU is needed to gate its power. + Please refer to the following document: + Documentation/devicetree/bindings/power/pd-samsung.yaml + maxItems: 1 + +required: + - compatible + - reg + - interrupts + - clocks + - clock-names + - "#iommu-cells" + +additionalProperties: false + +examples: + - | + #include <dt-bindings/clock/exynos5250.h> + + gsc_0: scaler@13e00000 { + compatible = "samsung,exynos5-gsc"; + reg = <0x13e00000 0x1000>; + interrupts = <0 85 0>; + power-domains = <&pd_gsc>; + clocks = <&clock CLK_GSCL0>; + clock-names = "gscl"; + iommus = <&sysmmu_gsc0>; + }; + + sysmmu_gsc0: iommu@13e80000 { + compatible = "samsung,exynos-sysmmu"; + reg = <0x13E80000 0x1000>; + interrupt-parent = <&combiner>; + interrupts = <2 0>; + clock-names = "sysmmu", "master"; + clocks = <&clock CLK_SMMU_GSCL0>, + <&clock CLK_GSCL0>; + power-domains = <&pd_gsc>; + #iommu-cells = <0>; + }; + |