linux/Documentation/devicetree/bindings/timer/xlnx,xps-timer.yaml
Sean Anderson f643490e1b dt-bindings: pwm: Add Xilinx AXI Timer
This adds a binding for the Xilinx LogiCORE IP AXI Timer. This device is a
"soft" block, so it has some parameters which would not be configurable in
most hardware. This binding is usually automatically generated by Xilinx's
tools, so the names and values of some properties should be kept as they
are, if possible. In addition, this binding is already in the kernel at
arch/microblaze/boot/dts/system.dts, and in user software such as QEMU.

The existing driver uses the clock-frequency property, or alternatively the
/cpus/timebase-frequency property as its frequency input. Because these
properties are deprecated, they have not been included with this schema.
All new bindings should use the clocks/clock-names properties to specify
the parent clock.

Because we need to init timer devices so early in boot, we determine if we
should use the PWM driver or the clocksource/clockevent driver by the
presence/absence, respectively, of #pwm-cells. Because both counters are
used by the PWM, there is no need for a separate property specifying which
counters are to be used for the PWM.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-04-22 18:21:10 +02:00

93 lines
1.8 KiB
YAML

# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/timer/xlnx,xps-timer.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Xilinx LogiCORE IP AXI Timer Device Tree Binding
maintainers:
- Sean Anderson <sean.anderson@seco.com>
properties:
compatible:
contains:
const: xlnx,xps-timer-1.00.a
clocks:
maxItems: 1
clock-names:
const: s_axi_aclk
interrupts:
maxItems: 1
reg:
maxItems: 1
'#pwm-cells': true
xlnx,count-width:
$ref: /schemas/types.yaml#/definitions/uint32
enum: [8, 16, 32]
default: 32
description:
The width of the counter(s), in bits.
xlnx,one-timer-only:
$ref: /schemas/types.yaml#/definitions/uint32
enum: [ 0, 1 ]
description:
Whether only one timer is present in this block.
required:
- compatible
- reg
- xlnx,one-timer-only
allOf:
- if:
required:
- '#pwm-cells'
then:
allOf:
- required:
- clocks
- properties:
xlnx,one-timer-only:
const: 0
else:
required:
- interrupts
- if:
required:
- clocks
then:
required:
- clock-names
additionalProperties: false
examples:
- |
timer@800e0000 {
clock-names = "s_axi_aclk";
clocks = <&zynqmp_clk 71>;
compatible = "xlnx,xps-timer-1.00.a";
reg = <0x800e0000 0x10000>;
interrupts = <0 39 2>;
xlnx,count-width = <16>;
xlnx,one-timer-only = <0x0>;
};
timer@800f0000 {
#pwm-cells = <0>;
clock-names = "s_axi_aclk";
clocks = <&zynqmp_clk 71>;
compatible = "xlnx,xps-timer-1.00.a";
reg = <0x800e0000 0x10000>;
xlnx,count-width = <32>;
xlnx,one-timer-only = <0x0>;
};