# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
# Copyright 2022 Unisoc Inc.
%YAML 1.2
---
$id: http://devicetree.org/schemas/gpio/sprd,gpio-eic.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Unisoc EIC controller
maintainers:
- Orson Zhai <[email protected]>
- Baolin Wang <[email protected]>
- Chunyan Zhang <[email protected]>
description: |
The EIC is the abbreviation of external interrupt controller, which can
be used only in input mode. The Spreadtrum platform has 2 EIC controllers,
one is in digital chip, and another one is in PMIC. The digital chip EIC
controller contains 4 sub-modules, i.e. EIC-debounce, EIC-latch, EIC-async and
EIC-sync. But the PMIC EIC controller contains only one EIC-debounce sub-
module.
The EIC-debounce sub-module provides up to 8 source input signal
connections. A debounce mechanism is used to capture the input signals'
stable status (millisecond resolution) and a single-trigger mechanism
is introduced into this sub-module to enhance the input event detection
reliability. In addition, this sub-module's clock can be shut off
automatically to reduce power dissipation. Moreover the debounce range
is from 1ms to 4s with a step size of 1ms. The input signal will be
ignored if it is asserted for less than 1 ms.
The EIC-latch sub-module is used to latch some special power down signals
and generate interrupts, since the EIC-latch does not depend on the APB
clock to capture signals.
The EIC-async sub-module uses a 32kHz clock to capture the short signals
(microsecond resolution) to generate interrupts by level or edge trigger.
The EIC-sync is similar with GPIO's input function, which is a synchronized
signal input register. It can generate interrupts by level or edge trigger
when detecting input signals.
properties:
compatible:
oneOf:
- enum:
- sprd,sc9860-eic-debounce
- sprd,sc9860-eic-latch
- sprd,sc9860-eic-async
- sprd,sc9860-eic-sync
- sprd,sc2731-eic
- items:
- enum:
- sprd,ums512-eic-debounce
- const: sprd,sc9860-eic-debounce
- items:
- enum:
- sprd,ums512-eic-latch
- const: sprd,sc9860-eic-latch
- items:
- enum:
- sprd,ums512-eic-async
- const: sprd,sc9860-eic-async
- items:
- enum:
- sprd,ums512-eic-sync
- const: sprd,sc9860-eic-sync
- items:
- enum:
- sprd,sc2730-eic
- const: sprd,sc2731-eic
reg:
minItems: 1
maxItems: 3
description:
EIC controller can support maximum 3 banks which has its own
address base.
gpio-controller: true
"#gpio-cells":
const: 2
interrupt-controller: true
"#interrupt-cells":
const: 2
interrupts:
maxItems: 1
description:
The interrupt shared by all GPIO lines for this controller.
required:
- compatible
- reg
- gpio-controller
- "#gpio-cells"
- interrupt-controller
- "#interrupt-cells"
- interrupts
additionalProperties: false
examples:
- |
#include <dt-bindings/interrupt-controller/arm-gic.h>
soc {
#address-cells = <2>;
#size-cells = <2>;
eic_debounce: gpio@40210000 {
compatible = "sprd,sc9860-eic-debounce";
reg = <0 0x40210000 0 0x80>;
gpio-controller;
#gpio-cells = <2>;
interrupt-controller;
#interrupt-cells = <2>;
interrupts = <GIC_SPI 52 IRQ_TYPE_LEVEL_HIGH>;
};
};
...
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