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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /Documentation/devicetree/bindings/spi/sprd,spi-adi.yaml
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
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Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+# 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>;
+ };
+ };
+...