Commit 4d2bb3e6 authored by Rob Herring's avatar Rob Herring

dt-bindings: timer: Convert ARM timer bindings to json-schema

Convert ARM timers to DT schema format using json-schema.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent 0175ce4a
* ARM architected timer
ARM cores may have a per-core architected timer, which provides per-cpu timers,
or a memory mapped architected timer, which provides up to 8 frames with a
physical and optional virtual timer per frame.
The per-core architected timer is attached to a GIC to deliver its
per-processor interrupts via PPIs. The memory mapped timer is attached to a GIC
to deliver its interrupts via SPIs.
** CP15 Timer node properties:
- compatible : Should at least contain one of
"arm,armv7-timer"
"arm,armv8-timer"
- interrupts : Interrupt list for secure, non-secure, virtual and
hypervisor timers, in that order.
- clock-frequency : The frequency of the main counter, in Hz. Should be present
only where necessary to work around broken firmware which does not configure
CNTFRQ on all CPUs to a uniform correct value. Use of this property is
strongly discouraged; fix your firmware unless absolutely impossible.
- always-on : a boolean property. If present, the timer is powered through an
always-on power domain, therefore it never loses context.
- fsl,erratum-a008585 : A boolean property. Indicates the presence of
QorIQ erratum A-008585, which says that reading the counter is
unreliable unless the same value is returned by back-to-back reads.
This also affects writes to the tval register, due to the implicit
counter read.
- hisilicon,erratum-161010101 : A boolean property. Indicates the
presence of Hisilicon erratum 161010101, which says that reading the
counters is unreliable in some cases, and reads may return a value 32
beyond the correct value. This also affects writes to the tval
registers, due to the implicit counter read.
** Optional properties:
- arm,cpu-registers-not-fw-configured : Firmware does not initialize
any of the generic timer CPU registers, which contain their
architecturally-defined reset values. Only supported for 32-bit
systems which follow the ARMv7 architected reset values.
- arm,no-tick-in-suspend : The main counter does not tick when the system is in
low-power system suspend on some SoCs. This behavior does not match the
Architecture Reference Manual's specification that the system counter "must
be implemented in an always-on power domain."
Example:
timer {
compatible = "arm,cortex-a15-timer",
"arm,armv7-timer";
interrupts = <1 13 0xf08>,
<1 14 0xf08>,
<1 11 0xf08>,
<1 10 0xf08>;
clock-frequency = <100000000>;
};
** Memory mapped timer node properties:
- compatible : Should at least contain "arm,armv7-timer-mem".
- clock-frequency : The frequency of the main counter, in Hz. Should be present
only when firmware has not configured the MMIO CNTFRQ registers.
- reg : The control frame base address.
Note that #address-cells, #size-cells, and ranges shall be present to ensure
the CPU can address a frame's registers.
A timer node has up to 8 frame sub-nodes, each with the following properties:
- frame-number: 0 to 7.
- interrupts : Interrupt list for physical and virtual timers in that order.
The virtual timer interrupt is optional.
- reg : The first and second view base addresses in that order. The second view
base address is optional.
- status : "disabled" indicates the frame is not available for use. Optional.
Example:
timer@f0000000 {
compatible = "arm,armv7-timer-mem";
#address-cells = <1>;
#size-cells = <1>;
ranges;
reg = <0xf0000000 0x1000>;
clock-frequency = <50000000>;
frame@f0001000 {
frame-number = <0>
interrupts = <0 13 0x8>,
<0 14 0x8>;
reg = <0xf0001000 0x1000>,
<0xf0002000 0x1000>;
};
frame@f0003000 {
frame-number = <1>
interrupts = <0 15 0x8>;
reg = <0xf0003000 0x1000>;
};
};
# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/timer/arm,arch_timer.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: ARM architected timer
maintainers:
- Marc Zyngier <marc.zyngier@arm.com>
- Mark Rutland <mark.rutland@arm.com>
description: |+
ARM cores may have a per-core architected timer, which provides per-cpu timers,
or a memory mapped architected timer, which provides up to 8 frames with a
physical and optional virtual timer per frame.
The per-core architected timer is attached to a GIC to deliver its
per-processor interrupts via PPIs. The memory mapped timer is attached to a GIC
to deliver its interrupts via SPIs.
properties:
compatible:
oneOf:
- items:
- enum:
- arm,cortex-a15-timer
- enum:
- arm,armv7-timer
- items:
- enum:
- arm,armv7-timer
- items:
- enum:
- arm,armv8-timer
interrupts:
items:
- description: secure timer irq
- description: non-secure timer irq
- description: virtual timer irq
- description: hypervisor timer irq
clock-frequency:
description: The frequency of the main counter, in Hz. Should be present
only where necessary to work around broken firmware which does not configure
CNTFRQ on all CPUs to a uniform correct value. Use of this property is
strongly discouraged; fix your firmware unless absolutely impossible.
always-on:
type: boolean
description: If present, the timer is powered through an always-on power
domain, therefore it never loses context.
fsl,erratum-a008585:
type: boolean
description: Indicates the presence of QorIQ erratum A-008585, which says
that reading the counter is unreliable unless the same value is returned
by back-to-back reads. This also affects writes to the tval register, due
to the implicit counter read.
hisilicon,erratum-161010101:
type: boolean
description: Indicates the presence of Hisilicon erratum 161010101, which
says that reading the counters is unreliable in some cases, and reads may
return a value 32 beyond the correct value. This also affects writes to
the tval registers, due to the implicit counter read.
arm,cpu-registers-not-fw-configured:
type: boolean
description: Firmware does not initialize any of the generic timer CPU
registers, which contain their architecturally-defined reset values. Only
supported for 32-bit systems which follow the ARMv7 architected reset
values.
arm,no-tick-in-suspend:
type: boolean
description: The main counter does not tick when the system is in
low-power system suspend on some SoCs. This behavior does not match the
Architecture Reference Manual's specification that the system counter "must
be implemented in an always-on power domain."
required:
- compatible
oneOf:
- required:
- interrupts
- required:
- interrupts-extended
examples:
- |
timer {
compatible = "arm,cortex-a15-timer",
"arm,armv7-timer";
interrupts = <1 13 0xf08>,
<1 14 0xf08>,
<1 11 0xf08>,
<1 10 0xf08>;
clock-frequency = <100000000>;
};
...
# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/timer/arm,arch_timer_mmio.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: ARM memory mapped architected timer
maintainers:
- Marc Zyngier <marc.zyngier@arm.com>
- Mark Rutland <mark.rutland@arm.com>
description: |+
ARM cores may have a memory mapped architected timer, which provides up to 8
frames with a physical and optional virtual timer per frame.
The memory mapped timer is attached to a GIC to deliver its interrupts via SPIs.
properties:
compatible:
items:
- enum:
- arm,armv7-timer-mem
reg:
maxItems: 1
description: The control frame base address
'#address-cells':
enum: [1, 2]
'#size-cells':
const: 1
clock-frequency:
description: The frequency of the main counter, in Hz. Should be present
only where necessary to work around broken firmware which does not configure
CNTFRQ on all CPUs to a uniform correct value. Use of this property is
strongly discouraged; fix your firmware unless absolutely impossible.
always-on:
type: boolean
description: If present, the timer is powered through an always-on power
domain, therefore it never loses context.
arm,cpu-registers-not-fw-configured:
type: boolean
description: Firmware does not initialize any of the generic timer CPU
registers, which contain their architecturally-defined reset values. Only
supported for 32-bit systems which follow the ARMv7 architected reset
values.
arm,no-tick-in-suspend:
type: boolean
description: The main counter does not tick when the system is in
low-power system suspend on some SoCs. This behavior does not match the
Architecture Reference Manual's specification that the system counter "must
be implemented in an always-on power domain."
patternProperties:
'^frame@[0-9a-z]*$':
description: A timer node has up to 8 frame sub-nodes, each with the following properties.
properties:
frame-number:
allOf:
- $ref: "/schemas/types.yaml#/definitions/uint32"
- minimum: 0
maximum: 7
interrupts:
minItems: 1
maxItems: 2
items:
- description: physical timer irq
- description: virtual timer irq
reg :
minItems: 1
maxItems: 2
items:
- description: 1st view base address
- description: 2nd optional view base address
required:
- frame-number
- interrupts
- reg
required:
- compatible
- reg
- '#address-cells'
- '#size-cells'
examples:
- |
timer@f0000000 {
compatible = "arm,armv7-timer-mem";
#address-cells = <1>;
#size-cells = <1>;
ranges;
reg = <0xf0000000 0x1000>;
clock-frequency = <50000000>;
frame@f0001000 {
frame-number = <0>;
interrupts = <0 13 0x8>,
<0 14 0x8>;
reg = <0xf0001000 0x1000>,
<0xf0002000 0x1000>;
};
frame@f0003000 {
frame-number = <1>;
interrupts = <0 15 0x8>;
reg = <0xf0003000 0x1000>;
};
};
...
* ARM Global Timer
Cortex-A9 are often associated with a per-core Global timer.
** Timer node required properties:
- compatible : should contain
* "arm,cortex-a5-global-timer" for Cortex-A5 global timers.
* "arm,cortex-a9-global-timer" for Cortex-A9 global
timers or any compatible implementation. Note: driver
supports versions r2p0 and above.
- interrupts : One interrupt to each core
- reg : Specify the base address and the size of the GT timer
register window.
- clocks : Should be phandle to a clock.
Example:
timer@2c000600 {
compatible = "arm,cortex-a9-global-timer";
reg = <0x2c000600 0x20>;
interrupts = <1 13 0xf01>;
clocks = <&arm_periph_clk>;
};
# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/timer/arm,global_timer.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: ARM Global Timer
maintainers:
- Stuart Menefy <stuart.menefy@st.com>
description:
Cortex-A9 are often associated with a per-core Global timer.
properties:
compatible:
items:
- enum:
- arm,cortex-a5-global-timer
- arm,cortex-a9-global-timer
description: driver supports versions r2p0 and above.
reg:
maxItems: 1
interrupts:
maxItems: 1
clocks:
maxItems: 1
required:
- compatible
- reg
- clocks
examples:
- |
timer@2c000600 {
compatible = "arm,cortex-a9-global-timer";
reg = <0x2c000600 0x20>;
interrupts = <1 13 0xf01>;
clocks = <&arm_periph_clk>;
};
...
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