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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 */
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> --- Changes in v3: - Removed usi0 "status" property from the example - Made child nodes pattern allow only serial/spi/i2c node names - Moved all USIv2 specific properties under corresponding "if:" - Renamed compatible from samsung,exynos-usi-v2 to samsung,exynos850-usi - Related: submitted separate patch removing warning on "make dt_binding_check" for USI bindings Changes in v2: - Combined dt-bindings doc and dt-bindings header patches - Added i2c node to example in bindings doc - Added mentioning of shared internal circuits - Added USI_V2_NONE value to bindings header .../bindings/soc/samsung/exynos-usi.yaml | 159 ++++++++++++++++++ include/dt-bindings/soc/samsung,exynos-usi.h | 17 ++ 2 files changed, 176 insertions(+) create mode 100644 Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml create mode 100644 include/dt-bindings/soc/samsung,exynos-usi.h