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Diffstat (limited to 'Documentation/devicetree/bindings/fsi')
6 files changed, 311 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/fsi/fsi-master-aspeed.txt b/Documentation/devicetree/bindings/fsi/fsi-master-aspeed.txt new file mode 100644 index 000000000..9853fefff --- /dev/null +++ b/Documentation/devicetree/bindings/fsi/fsi-master-aspeed.txt @@ -0,0 +1,36 @@ +Device-tree bindings for AST2600 FSI master +------------------------------------------- + +The AST2600 contains two identical FSI masters. They share a clock and have a +separate interrupt line and output pins. + +Required properties: + - compatible: "aspeed,ast2600-fsi-master" + - reg: base address and length + - clocks: phandle and clock number + - interrupts: platform dependent interrupt description + - pinctrl-0: phandle to pinctrl node + - pinctrl-names: pinctrl state + +Optional properties: + - cfam-reset-gpios: GPIO for CFAM reset + + - fsi-routing-gpios: GPIO for setting the FSI mux (internal or cabled) + - fsi-mux-gpios: GPIO for detecting the desired FSI mux state + + +Examples: + + fsi-master { + compatible = "aspeed,ast2600-fsi-master", "fsi-master"; + reg = <0x1e79b000 0x94>; + interrupts = <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>; + pinctrl-names = "default"; + pinctrl-0 = <&pinctrl_fsi1_default>; + clocks = <&syscon ASPEED_CLK_GATE_FSICLK>; + + fsi-routing-gpios = <&gpio0 ASPEED_GPIO(Q, 7) GPIO_ACTIVE_HIGH>; + fsi-mux-gpios = <&gpio0 ASPEED_GPIO(B, 0) GPIO_ACTIVE_HIGH>; + + cfam-reset-gpios = <&gpio0 ASPEED_GPIO(Q, 0) GPIO_ACTIVE_LOW>; + }; diff --git a/Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt b/Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt new file mode 100644 index 000000000..3dc752db7 --- /dev/null +++ b/Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt @@ -0,0 +1,36 @@ +Device-tree bindings for ColdFire offloaded gpio-based FSI master driver +------------------------------------------------------------------------ + +Required properties: + - compatible = + "aspeed,ast2400-cf-fsi-master" for an AST2400 based system + or + "aspeed,ast2500-cf-fsi-master" for an AST2500 based system + + - clock-gpios = <gpio-descriptor>; : GPIO for FSI clock + - data-gpios = <gpio-descriptor>; : GPIO for FSI data signal + - enable-gpios = <gpio-descriptor>; : GPIO for enable signal + - trans-gpios = <gpio-descriptor>; : GPIO for voltage translator enable + - mux-gpios = <gpio-descriptor>; : GPIO for pin multiplexing with other + functions (eg, external FSI masters) + - memory-region = <phandle>; : Reference to the reserved memory for + the ColdFire. Must be 2M aligned on + AST2400 and 1M aligned on AST2500 + - aspeed,sram = <phandle>; : Reference to the SRAM node. + - aspeed,cvic = <phandle>; : Reference to the CVIC node. + +Examples: + + fsi-master { + compatible = "aspeed,ast2500-cf-fsi-master", "fsi-master"; + + clock-gpios = <&gpio 0>; + data-gpios = <&gpio 1>; + enable-gpios = <&gpio 2>; + trans-gpios = <&gpio 3>; + mux-gpios = <&gpio 4>; + + memory-region = <&coldfire_memory>; + aspeed,sram = <&sram>; + aspeed,cvic = <&cvic>; + } diff --git a/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt new file mode 100644 index 000000000..1e4424507 --- /dev/null +++ b/Documentation/devicetree/bindings/fsi/fsi-master-gpio.txt @@ -0,0 +1,28 @@ +Device-tree bindings for gpio-based FSI master driver +----------------------------------------------------- + +Required properties: + - compatible = "fsi-master-gpio"; + - clock-gpios = <gpio-descriptor>; : GPIO for FSI clock + - data-gpios = <gpio-descriptor>; : GPIO for FSI data signal + +Optional properties: + - enable-gpios = <gpio-descriptor>; : GPIO for enable signal + - trans-gpios = <gpio-descriptor>; : GPIO for voltage translator enable + - mux-gpios = <gpio-descriptor>; : GPIO for pin multiplexing with other + functions (eg, external FSI masters) + - no-gpio-delays; : Don't add extra delays between GPIO + accesses. This is useful when the HW + GPIO block is running at a low enough + frequency. + +Examples: + + fsi-master { + compatible = "fsi-master-gpio", "fsi-master"; + clock-gpios = <&gpio 0>; + data-gpios = <&gpio 1>; + enable-gpios = <&gpio 2>; + trans-gpios = <&gpio 3>; + mux-gpios = <&gpio 4>; + } diff --git a/Documentation/devicetree/bindings/fsi/fsi.txt b/Documentation/devicetree/bindings/fsi/fsi.txt new file mode 100644 index 000000000..afb4eccab --- /dev/null +++ b/Documentation/devicetree/bindings/fsi/fsi.txt @@ -0,0 +1,156 @@ +FSI bus & engine generic device tree bindings +============================================= + +The FSI bus is probe-able, so the OS is able to enumerate FSI slaves, and +engines within those slaves. However, we have a facility to match devicetree +nodes to probed engines. This allows for fsi engines to expose non-probeable +busses, which are then exposed by the device tree. For example, an FSI engine +that is an I2C master - the I2C bus can be described by the device tree under +the engine's device tree node. + +FSI masters may require their own DT nodes (to describe the master HW itself); +that requirement is defined by the master's implementation, and is described by +the fsi-master-* binding specifications. + +Under the masters' nodes, we can describe the bus topology using nodes to +represent the FSI slaves and their slave engines. As a basic outline: + + fsi-master { + /* top-level of FSI bus topology, bound to an FSI master driver and + * exposes an FSI bus */ + + fsi-slave@<link,id> { + /* this node defines the FSI slave device, and is handled + * entirely with FSI core code */ + + fsi-slave-engine@<addr> { + /* this node defines the engine endpoint & address range, which + * is bound to the relevant fsi device driver */ + ... + }; + + fsi-slave-engine@<addr> { + ... + }; + + }; + }; + +Note that since the bus is probe-able, some (or all) of the topology may +not be described; this binding only provides an optional facility for +adding subordinate device tree nodes as children of FSI engines. + +FSI masters +----------- + +FSI master nodes declare themselves as such with the "fsi-master" compatible +value. It's likely that an implementation-specific compatible value will +be needed as well, for example: + + compatible = "fsi-master-gpio", "fsi-master"; + +Since the master nodes describe the top-level of the FSI topology, they also +need to declare the FSI-standard addressing scheme. This requires two cells for +addresses (link index and slave ID), and no size: + + #address-cells = <2>; + #size-cells = <0>; + +An optional boolean property can be added to indicate that a particular master +should not scan for connected devices at initialization time. This is +necessary in cases where a scan could cause arbitration issues with other +masters that may be present on the bus. + + no-scan-on-init; + +FSI slaves +---------- + +Slaves are identified by a (link-index, slave-id) pair, so require two cells +for an address identifier. Since these are not a range, no size cells are +required. For an example, a slave on link 1, with ID 2, could be represented +as: + + cfam@1,2 { + reg = <1 2>; + [...]; + } + +Each slave provides an address-space, under which the engines are accessible. +That address space has a maximum of 23 bits, so we use one cell to represent +addresses and sizes in the slave address space: + + #address-cells = <1>; + #size-cells = <1>; + +Optionally, a slave can provide a global unique chip ID which is used to +identify the physical location of the chip in a system specific way + + chip-id = <0>; + +FSI engines (devices) +--------------------- + +Engines are identified by their address under the slaves' address spaces. We +use a single cell for address and size. Engine nodes represent the endpoint +FSI device, and are passed to those FSI device drivers' ->probe() functions. + +For example, for a slave using a single 0x400-byte page starting at address +0xc00: + + engine@c00 { + reg = <0xc00 0x400>; + }; + + +Full example +------------ + +Here's an example that illustrates: + - an FSI master + - connected to an FSI slave + - that contains an engine that is an I2C master + - connected to an I2C EEPROM + +The FSI master may be connected to additional slaves, and slaves may have +additional engines, but they don't necessarily need to be describe in the +device tree if no extra platform information is required. + + /* The GPIO-based FSI master node, describing the top level of the + * FSI bus + */ + gpio-fsi { + compatible = "fsi-master-gpio", "fsi-master"; + #address-cells = <2>; + #size-cells = <0>; + + /* A FSI slave (aka. CFAM) at link 0, ID 0. */ + cfam@0,0 { + reg = <0 0>; + #address-cells = <1>; + #size-cells = <1>; + chip-id = <0>; + + /* FSI engine at 0xc00, using a single page. In this example, + * it's an I2C master controller, so subnodes describe the + * I2C bus. + */ + i2c-controller@c00 { + reg = <0xc00 0x400>; + + /* Engine-specific data. In this case, we're describing an + * I2C bus, so we're conforming to the generic I2C binding + */ + compatible = "some-vendor,fsi-i2c-controller"; + #address-cells = <1>; + #size-cells = <1>; + + /* I2C endpoint device: an Atmel EEPROM */ + eeprom@50 { + compatible = "atmel,24c256"; + reg = <0x50>; + pagesize = <64>; + }; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/fsi/ibm,fsi2spi.yaml b/Documentation/devicetree/bindings/fsi/ibm,fsi2spi.yaml new file mode 100644 index 000000000..e42527865 --- /dev/null +++ b/Documentation/devicetree/bindings/fsi/ibm,fsi2spi.yaml @@ -0,0 +1,39 @@ +# SPDX-License-Identifier: (GPL-2.0-or-later) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/fsi/ibm,fsi2spi.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: IBM FSI-attached SPI controllers + +maintainers: + - Eddie James <eajames@linux.ibm.com> + +description: | + This binding describes an FSI CFAM engine called the FSI2SPI. Therefore this + node will always be a child of an FSI CFAM node; see fsi.txt for details on + FSI slave and CFAM nodes. This FSI2SPI engine provides access to a number of + SPI controllers. + +properties: + compatible: + enum: + - ibm,fsi2spi + - ibm,fsi2spi-restricted + + reg: + items: + - description: FSI slave address + +required: + - compatible + - reg + +additionalProperties: false + +examples: + - | + fsi2spi@1c00 { + compatible = "ibm,fsi2spi"; + reg = <0x1c00 0x400>; + }; diff --git a/Documentation/devicetree/bindings/fsi/ibm,p9-occ.txt b/Documentation/devicetree/bindings/fsi/ibm,p9-occ.txt new file mode 100644 index 000000000..99ca9862a --- /dev/null +++ b/Documentation/devicetree/bindings/fsi/ibm,p9-occ.txt @@ -0,0 +1,16 @@ +Device-tree bindings for FSI-attached POWER9 On-Chip Controller (OCC) +--------------------------------------------------------------------- + +This is the binding for the P9 On-Chip Controller accessed over FSI from a +service processor. See fsi.txt for details on bindings for FSI slave and CFAM +nodes. The OCC is not an FSI slave device itself, rather it is accessed +through the SBE fifo. + +Required properties: + - compatible = "ibm,p9-occ" + +Examples: + + occ { + compatible = "ibm,p9-occ"; + }; |