dt-bindings: soc: samsung: Add Exynos USI bindings

Add constants for choosing USIv2 configuration mode in device tree.
Those are further used in USI driver to figure out which value to write
into SW_CONF register. Also document USIv2 IP-core bindings.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211204195757.8600-2-semen.protsenko@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
This commit is contained in:
Sam Protsenko 2021-12-04 21:57:53 +02:00 committed by Krzysztof Kozlowski
parent fa55b7dcdc
commit e522ae91b8
2 changed files with 176 additions and 0 deletions

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/soc/samsung/exynos-usi.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Samsung's Exynos USI (Universal Serial Interface) binding
maintainers:
- Sam Protsenko <semen.protsenko@linaro.org>
- Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
description: |
USI IP-core provides selectable serial protocol (UART, SPI or High-Speed I2C).
USI shares almost all internal circuits within each protocol, so only one
protocol can be chosen at a time. USI is modeled as a node with zero or more
child nodes, each representing a serial sub-node device. The mode setting
selects which particular function will be used.
Refer to next bindings documentation for information on protocol subnodes that
can exist under USI node:
[1] Documentation/devicetree/bindings/serial/samsung_uart.yaml
[2] Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
[3] Documentation/devicetree/bindings/spi/spi-samsung.txt
properties:
$nodename:
pattern: "^usi@[0-9a-f]+$"
compatible:
enum:
- samsung,exynos850-usi # for USIv2 (Exynos850, ExynosAutoV9)
reg: true
clocks: true
clock-names: true
ranges: true
"#address-cells":
const: 1
"#size-cells":
const: 1
samsung,sysreg:
$ref: /schemas/types.yaml#/definitions/phandle-array
description:
Should be phandle/offset pair. The phandle to System Register syscon node
(for the same domain where this USI controller resides) and the offset
of SW_CONF register for this USI controller.
samsung,mode:
$ref: /schemas/types.yaml#/definitions/uint32
description:
Selects USI function (which serial protocol to use). Refer to
<include/dt-bindings/soc/samsung,exynos-usi.h> for valid USI mode values.
samsung,clkreq-on:
type: boolean
description:
Enable this property if underlying protocol requires the clock to be
continuously provided without automatic gating. As suggested by SoC
manual, it should be set in case of SPI/I2C slave, UART Rx and I2C
multi-master mode. Usually this property is needed if USI mode is set
to "UART".
This property is optional.
patternProperties:
# All other properties should be child nodes
"^(serial|spi|i2c)@[0-9a-f]+$":
type: object
description: Child node describing underlying USI serial protocol
required:
- compatible
- ranges
- "#address-cells"
- "#size-cells"
- samsung,sysreg
- samsung,mode
if:
properties:
compatible:
contains:
enum:
- samsung,exynos850-usi
then:
properties:
reg:
maxItems: 1
clocks:
items:
- description: Bus (APB) clock
- description: Operating clock for UART/SPI/I2C protocol
clock-names:
items:
- const: pclk
- const: ipclk
required:
- reg
- clocks
- clock-names
else:
properties:
reg: false
clocks: false
clock-names: false
samsung,clkreq-on: false
additionalProperties: false
examples:
- |
#include <dt-bindings/interrupt-controller/arm-gic.h>
#include <dt-bindings/soc/samsung,exynos-usi.h>
usi0: usi@138200c0 {
compatible = "samsung,exynos850-usi";
reg = <0x138200c0 0x20>;
samsung,sysreg = <&sysreg_peri 0x1010>;
samsung,mode = <USI_V2_UART>;
samsung,clkreq-on; /* needed for UART mode */
#address-cells = <1>;
#size-cells = <1>;
ranges;
clocks = <&cmu_peri 32>, <&cmu_peri 31>;
clock-names = "pclk", "ipclk";
serial_0: serial@13820000 {
compatible = "samsung,exynos850-uart";
reg = <0x13820000 0xc0>;
interrupts = <GIC_SPI 227 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&cmu_peri 32>, <&cmu_peri 31>;
clock-names = "uart", "clk_uart_baud0";
status = "disabled";
};
hsi2c_0: i2c@13820000 {
compatible = "samsung,exynosautov9-hsi2c";
reg = <0x13820000 0xc0>;
interrupts = <GIC_SPI 227 IRQ_TYPE_LEVEL_HIGH>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&cmu_peri 32>, <&cmu_peri 31>;
clock-names = "hsi2c_pclk", "hsi2c";
status = "disabled";
};
};

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/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
/*
* Copyright (c) 2021 Linaro Ltd.
* Author: Sam Protsenko <semen.protsenko@linaro.org>
*
* Device Tree bindings for Samsung Exynos USI (Universal Serial Interface).
*/
#ifndef __DT_BINDINGS_SAMSUNG_EXYNOS_USI_H
#define __DT_BINDINGS_SAMSUNG_EXYNOS_USI_H
#define USI_V2_NONE 0
#define USI_V2_UART 1
#define USI_V2_SPI 2
#define USI_V2_I2C 3
#endif /* __DT_BINDINGS_SAMSUNG_EXYNOS_USI_H */