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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /Documentation/devicetree/bindings/spi/sprd,spi-adi.yaml | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/devicetree/bindings/spi/sprd,spi-adi.yaml')
-rw-r--r-- | Documentation/devicetree/bindings/spi/sprd,spi-adi.yaml | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/spi/sprd,spi-adi.yaml b/Documentation/devicetree/bindings/spi/sprd,spi-adi.yaml new file mode 100644 index 000000000..a3ab1a1f1 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/sprd,spi-adi.yaml @@ -0,0 +1,104 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) + +%YAML 1.2 +--- +$id: "http://devicetree.org/schemas/spi/sprd,spi-adi.yaml#" +$schema: "http://devicetree.org/meta-schemas/core.yaml#" + +title: Spreadtrum ADI controller + +maintainers: + - Orson Zhai <orsonzhai@gmail.com> + - Baolin Wang <baolin.wang7@gmail.com> + - Chunyan Zhang <zhang.lyra@gmail.com> + +description: | + ADI is the abbreviation of Anolog-Digital interface, which is used to access + analog chip (such as PMIC) from digital chip. ADI controller follows the SPI + framework for its hardware implementation is alike to SPI bus and its timing + is compatile to SPI timing. + + ADI controller has 50 channels including 2 software read/write channels and + 48 hardware channels to access analog chip. For 2 software read/write channels, + users should set ADI registers to access analog chip. For hardware channels, + we can configure them to allow other hardware components to use it independently, + which means we can just link one analog chip address to one hardware channel, + then users can access the mapped analog chip address by this hardware channel + triggered by hardware components instead of ADI software channels. + + Thus we introduce one property named "sprd,hw-channels" to configure hardware + channels, the first value specifies the hardware channel id which is used to + transfer data triggered by hardware automatically, and the second value specifies + the analog chip address where user want to access by hardware components. + + Since we have multi-subsystems will use unique ADI to access analog chip, when + one system is reading/writing data by ADI software channels, that should be under + one hardware spinlock protection to prevent other systems from reading/writing + data by ADI software channels at the same time, or two parallel routine of setting + ADI registers will make ADI controller registers chaos to lead incorrect results. + Then we need one hardware spinlock to synchronize between the multiple subsystems. + + The new version ADI controller supplies multiple master channels for different + subsystem accessing, that means no need to add hardware spinlock to synchronize, + thus change the hardware spinlock support to be optional to keep backward + compatibility. + +allOf: + - $ref: /schemas/spi/spi-controller.yaml# + +properties: + compatible: + enum: + - sprd,sc9860-adi + - sprd,sc9863-adi + - sprd,ums512-adi + + reg: + maxItems: 1 + + hwlocks: + maxItems: 1 + + hwlock-names: + const: adi + + sprd,hw-channels: + $ref: /schemas/types.yaml#/definitions/uint32-matrix + description: A list of hardware channels + minItems: 1 + maxItems: 48 + items: + items: + - description: The hardware channel id which is used to transfer data + triggered by hardware automatically, channel id 0-1 are for software + use, 2-49 are hardware channels. + minimum: 2 + maximum: 49 + - description: The analog chip address where user want to access by + hardware components. + +required: + - compatible + - reg + - '#address-cells' + - '#size-cells' + +unevaluatedProperties: false + +examples: + - | + aon { + #address-cells = <2>; + #size-cells = <2>; + + adi_bus: spi@40030000 { + compatible = "sprd,sc9860-adi"; + reg = <0 0x40030000 0 0x10000>; + hwlocks = <&hwlock1 0>; + hwlock-names = "adi"; + #address-cells = <1>; + #size-cells = <0>; + sprd,hw-channels = <30 0x8c20>; + }; + }; +... |