This patch adds the documentation of the device-tree binding for MediaTek Common DRAM Controller. Signed-off-by: Po-Kai Chi <pk.chi@xxxxxxxxxxxx> --- .../memory-controllers/mediatek,dramc.yaml | 155 ++++++++++++++++++++ 1 file changed, 155 insertions(+) create mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,dramc.yaml diff --git a/Documentation/devicetree/bindings/memory-controllers/mediatek,dramc.yaml b/Documentation/devicetree/bindings/memory-controllers/mediatek,dramc.yaml new file mode 100644 index 0000000..0217ce0 --- /dev/null +++ b/Documentation/devicetree/bindings/memory-controllers/mediatek,dramc.yaml @@ -0,0 +1,155 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +# Copyright (c) 2021 MediaTek Inc. +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/memory-controllers/mediatek,dramc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: MediaTek DRAM Controller + +maintainers: + - Po-Kai Chi <pk.chi@xxxxxxxxxxxx> + +description: | + MediaTek DRAM controller (DRAMC) provides an interface to query information + about DRAM which collected from bootloader and device tree. + This is mainly used by MediaTek Extended Memory Interface (EMI) and DVFS Resource + Control (DVFSRC). + +properties: + compatible: + items: + - enum: + - mediatek,mt6779-dramc + + reg: + description: + Base address of MediaTek DRAM related hardware modules, each channel has + its own base address in order of + DRAMC_AO_{CH}, DRAMC_NAO_{CH}, DDRPHY_AO_{CH}. + minItems: 3 # 3 * N channels + maxItems: 6 + + dram_type: + description: + The DRAM type of current DRAM chip. + This property is filled in by bootloader according to the board hardware + configuration. + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 0 + maximum: 7 + + support_channel_cnt: + description: + The maximum DRAM channel count supported by SoC. + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 1 + maximum: 4 + + channel_cnt: + description: + The DRAM channel count of current DRAM chip. + This property is filled in by bootloader according to the board hardware + configuration. + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 1 + maximum: 4 + + rank_cnt: + description: + The DRAM rank count of current DRAM chip. + This property is filled in by bootloader according to the board hardware + configuration. + $ref: /schemas/types.yaml#/definitions/uint32 + minimum: 1 + maximum: 2 + + rank_size: + description: + The size of each DRAM rank. + This property is filled in by bootloader according to the board hardware + configuration. + $ref: /schemas/types.yaml#/definitions/uint64 + minItems: 1 + maxItems: 2 + items: + minimum: 0x0 + maximum: 0x100000000 # support up to 4GB in single rank + + mr_cnt: + description: + Specifies how many sets of DRAM mode register information to provide. + This property is filled in by bootloader according to the board hardware + configuration. + $ref: /schemas/types.yaml#/definitions/uint32 + maximum: 40 # total 40 MRs for JEDEC LPDDR4X + + mr: + description: + Pair of DRAM mode register information. + This property is filled in by bootloader according to the board hardware + configuration. + $ref: /schemas/types.yaml#/definitions/uint32-matrix + maxItems: 40 # align with mr_cnt + items: + items: + - description: + Mode register index + - description: + Mode register value + + freq_cnt: + description: + Specifies how many sets of DRAM data clock rate supported by SoC. + $ref: /schemas/types.yaml#/definitions/uint32 + + freq_step: + description: + The DRAM data clock rate may be slightly different from those defined + by the specification due to errors in multiples of the base frequency. + This describe the mapping from real data clock rate measured by + frequency meter to JEDEC data clock rate. + $ref: /schemas/types.yaml#/definitions/uint32-matrix + items: + items: + - description: + Real data rate + - description: + Spec data rate + +required: + - compatible + - reg + - dram_type + - support_channel_cnt + - channel_cnt + - rank_cnt + - mr_cnt + - freq_cnt + +additionalProperties: false + +examples: + - | + dramc@10230000 { + compatible = "mediatek,mt6779-dramc"; + reg = <0 0x10230000 0 0x2000>, /* DRAMC AO CHA */ + <0 0x10240000 0 0x2000>, /* DRAMC AO CHB */ + <0 0x10234000 0 0x1000>, /* DRAMC NAO CHA */ + <0 0x10244000 0 0x1000>, /* DRAMC NAO CHB */ + <0 0x10238000 0 0x2000>, /* DDRPHY AO CHA */ + <0 0x10248000 0 0x2000>; /* DDRPHY AO CHB */ + dram_type = <0>; + support_channel_cnt = <2>; + channel_cnt = <2>; + rank_cnt = <2>; + rank_size = <0x40000000 0x40000000>; + mr_cnt = <1>; + mr = <0x5 0xff>; + freq_cnt = <6>; + freq_step = <3718 3733>, + <3094 3200>, + <2392 2400>, + <1534 1600>, + <1196 1200>, + <754 800>; + }; -- 1.7.9.5
