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Diffstat (limited to 'Documentation/devicetree/bindings/gpio/nvidia,tegra186-gpio.yaml')
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diff --git a/Documentation/devicetree/bindings/gpio/nvidia,tegra186-gpio.yaml b/Documentation/devicetree/bindings/gpio/nvidia,tegra186-gpio.yaml new file mode 100644 index 000000000..4ef06b2ff --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/nvidia,tegra186-gpio.yaml @@ -0,0 +1,214 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gpio/nvidia,tegra186-gpio.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: NVIDIA Tegra GPIO Controller (Tegra186 and later) + +maintainers: + - Thierry Reding <thierry.reding@gmail.com> + - Jon Hunter <jonathanh@nvidia.com> + +description: | + Tegra186 contains two GPIO controllers; a main controller and an "AON" + controller. This binding document applies to both controllers. The register + layouts for the controllers share many similarities, but also some + significant differences. Hence, this document describes closely related but + different bindings and compatible values. + + The Tegra186 GPIO controller allows software to set the IO direction of, + and read/write the value of, numerous GPIO signals. Routing of GPIO signals + to package balls is under the control of a separate pin controller hardware + block. Two major sets of registers exist: + + a) Security registers, which allow configuration of allowed access to the + GPIO register set. These registers exist in a single contiguous block + of physical address space. The size of this block, and the security + features available, varies between the different GPIO controllers. + + Access to this set of registers is not necessary in all circumstances. + Code that wishes to configure access to the GPIO registers needs access + to these registers to do so. Code which simply wishes to read or write + GPIO data does not need access to these registers. + + b) GPIO registers, which allow manipulation of the GPIO signals. In some + GPIO controllers, these registers are exposed via multiple "physical + aliases" in address space, each of which access the same underlying + state. See the hardware documentation for rationale. Any particular + GPIO client is expected to access just one of these physical aliases. + + Tegra HW documentation describes a unified naming convention for all GPIOs + implemented by the SoC. Each GPIO is assigned to a port, and a port may + control a number of GPIOs. Thus, each GPIO is named according to an + alphabetical port name and an integer GPIO name within the port. For + example, GPIO_PA0, GPIO_PN6, or GPIO_PCC3. + + The number of ports implemented by each GPIO controller varies. The number + of implemented GPIOs within each port varies. GPIO registers within a + controller are grouped and laid out according to the port they affect. + + The mapping from port name to the GPIO controller that implements that + port, and the mapping from port name to register offset within a + controller, are both extremely non-linear. The header file + <dt-bindings/gpio/tegra186-gpio.h> describes the port-level mapping. In + that file, the naming convention for ports matches the HW documentation. + The values chosen for the names are alphabetically sorted within a + particular controller. Drivers need to map between the DT GPIO IDs and HW + register offsets using a lookup table. + + Each GPIO controller can generate a number of interrupt signals. Each + signal represents the aggregate status for all GPIOs within a set of + ports. Thus, the number of interrupt signals generated by a controller + varies as a rough function of the number of ports it implements. Note + that the HW documentation refers to both the overall controller HW + module and the sets-of-ports as "controllers". + + Each GPIO controller in fact generates multiple interrupts signals for + each set of ports. Each GPIO may be configured to feed into a specific + one of the interrupt signals generated by a set-of-ports. The intent is + for each generated signal to be routed to a different CPU, thus allowing + different CPUs to each handle subsets of the interrupts within a port. + The status of each of these per-port-set signals is reported via a + separate register. Thus, a driver needs to know which status register to + observe. This binding currently defines no configuration mechanism for + this. By default, drivers should use register + GPIO_${port}_INTERRUPT_STATUS_G1_0. Future revisions to the binding could + define a property to configure this. + +properties: + compatible: + enum: + - nvidia,tegra186-gpio + - nvidia,tegra186-gpio-aon + - nvidia,tegra194-gpio + - nvidia,tegra194-gpio-aon + - nvidia,tegra234-gpio + - nvidia,tegra234-gpio-aon + + reg-names: + items: + - const: security + - const: gpio + minItems: 1 + + reg: + items: + - description: Security configuration registers. + - description: | + GPIO control registers. This may cover either: + + a) The single physical alias that this OS should use. + b) All physical aliases that exist in the controller. This is + appropriate when the OS is responsible for managing assignment + of the physical aliases. + minItems: 1 + + interrupts: + description: The interrupt outputs from the HW block, one per set of + ports, in the order the HW manual describes them. The number of entries + required varies depending on compatible value. + + gpio-controller: true + + "#gpio-cells": + description: | + Indicates how many cells are used in a consumer's GPIO specifier. In the + specifier: + + - The first cell is the pin number. + See <dt-bindings/gpio/tegra186-gpio.h>. + - The second cell contains flags: + - Bit 0 specifies polarity + - 0: Active-high (normal). + - 1: Active-low (inverted). + const: 2 + + interrupt-controller: true + + "#interrupt-cells": + description: | + Indicates how many cells are used in a consumer's interrupt specifier. + In the specifier: + + - The first cell is the GPIO number. + See <dt-bindings/gpio/tegra186-gpio.h>. + - The second cell is contains flags: + - Bits [3:0] indicate trigger type and level: + - 1: Low-to-high edge triggered. + - 2: High-to-low edge triggered. + - 4: Active high level-sensitive. + - 8: Active low level-sensitive. + + Valid combinations are 1, 2, 3, 4, 8. + const: 2 + +allOf: + - if: + properties: + compatible: + contains: + enum: + - nvidia,tegra186-gpio + - nvidia,tegra194-gpio + - nvidia,tegra234-gpio + then: + properties: + interrupts: + minItems: 6 + maxItems: 48 + + - if: + properties: + compatible: + contains: + enum: + - nvidia,tegra186-gpio-aon + - nvidia,tegra194-gpio-aon + - nvidia,tegra234-gpio-aon + then: + properties: + interrupts: + minItems: 1 + maxItems: 4 + +required: + - compatible + - reg + - reg-names + - interrupts + +additionalProperties: false + +examples: + - | + #include <dt-bindings/interrupt-controller/irq.h> + + gpio@2200000 { + compatible = "nvidia,tegra186-gpio"; + reg-names = "security", "gpio"; + reg = <0x2200000 0x10000>, + <0x2210000 0x10000>; + interrupts = <0 47 IRQ_TYPE_LEVEL_HIGH>, + <0 50 IRQ_TYPE_LEVEL_HIGH>, + <0 53 IRQ_TYPE_LEVEL_HIGH>, + <0 56 IRQ_TYPE_LEVEL_HIGH>, + <0 59 IRQ_TYPE_LEVEL_HIGH>, + <0 180 IRQ_TYPE_LEVEL_HIGH>; + gpio-controller; + #gpio-cells = <2>; + interrupt-controller; + #interrupt-cells = <2>; + }; + + gpio@c2f0000 { + compatible = "nvidia,tegra186-gpio-aon"; + reg-names = "security", "gpio"; + reg = <0xc2f0000 0x1000>, + <0xc2f1000 0x1000>; + interrupts = <0 60 IRQ_TYPE_LEVEL_HIGH>; + gpio-controller; + #gpio-cells = <2>; + interrupt-controller; + #interrupt-cells = <2>; + }; |