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# SPDX-License-Identifier: GPL-2.0-only
%YAML 1.2
---
$id: http://devicetree.org/schemas/clock/ti/ti,divider-clock.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Texas Instruments divider clock
maintainers:
- Tero Kristo <kristo@kernel.org>
description: |
This clock It assumes a register-mapped adjustable clock rate divider
that does not gate and has only one input clock or parent. By default the
value programmed into the register is one less than the actual divisor value.
E.g:
register value actual divisor value
0 1
1 2
2 3
This assumption may be modified by the following optional properties:
ti,index-starts-at-one - valid divisor values start at 1, not the default
of 0. E.g:
register value actual divisor value
1 1
2 2
3 3
ti,index-power-of-two - valid divisor values are powers of two. E.g:
register value actual divisor value
0 1
1 2
2 4
Additionally an array of valid dividers may be supplied like so:
ti,dividers = <4>, <8>, <0>, <16>;
Which will map the resulting values to a divisor table by their index:
register value actual divisor value
0 4
1 8
2 <invalid divisor, skipped>
3 16
Any zero value in this array means the corresponding bit-value is invalid
and must not be used.
The binding must also provide the register to control the divider and
unless the divider array is provided, min and max dividers. Optionally
the number of bits to shift that mask, if necessary. If the shift value
is missing it is the same as supplying a zero shift.
This binding can also optionally provide support to the hardware autoidle
feature, see [1].
[1] Documentation/devicetree/bindings/clock/ti/autoidle.txt
properties:
compatible:
enum:
- ti,divider-clock
- ti,composite-divider-clock
"#clock-cells":
const: 0
clocks:
maxItems: 1
clock-output-names:
maxItems: 1
reg:
maxItems: 1
ti,dividers:
$ref: /schemas/types.yaml#/definitions/uint32-array
description:
array of integers defining divisors
ti,bit-shift:
$ref: /schemas/types.yaml#/definitions/uint32
description:
number of bits to shift the divider value
maximum: 31
default: 0
ti,min-div:
$ref: /schemas/types.yaml#/definitions/uint32
description:
min divisor for dividing the input clock rate, only
needed if the first divisor is offset from the default value (1)
minimum: 1
default: 1
ti,max-div:
$ref: /schemas/types.yaml#/definitions/uint32
description:
max divisor for dividing the input clock rate, only needed
if ti,dividers is not defined.
ti,index-starts-at-one:
type: boolean
description:
valid divisor programming starts at 1, not zero,
only valid if ti,dividers is not defined
ti,index-power-of-two:
type: boolean
description:
valid divisor programming must be a power of two,
only valid if ti,dividers is not defined.
ti,autoidle-shift:
$ref: /schemas/types.yaml#/definitions/uint32
description:
bit shift of the autoidle enable bit for the clock,
see [1].
maximum: 31
default: 0
ti,invert-autoidle-bit:
type: boolean
description:
autoidle is enabled by setting the bit to 0,
see [1]
ti,set-rate-parent:
type: boolean
description:
clk_set_rate is propagated to parent |
ti,latch-bit:
$ref: /schemas/types.yaml#/definitions/uint32
description:
latch the divider value to HW, only needed if the register
compatible access requires this. As an example dra76x DPLL_GMAC
H14 divider implements such behavior.
dependentSchemas:
ti,dividers:
properties:
ti,min-div: false
ti,max-div: false
ti,index-power-of-two: false
ti,index-starts-at-one: false
required:
- compatible
- "#clock-cells"
- clocks
- reg
additionalProperties: false
examples:
- |
bus {
#address-cells = <1>;
#size-cells = <0>;
clock-controller@190 {
#clock-cells = <0>;
compatible = "ti,divider-clock";
clocks = <&dpll_usb_ck>;
ti,max-div = <127>;
reg = <0x190>;
ti,index-starts-at-one;
};
clock-controller@528 {
#clock-cells = <0>;
compatible = "ti,divider-clock";
clocks = <&abe_clk>;
ti,bit-shift = <24>;
reg = <0x528>;
ti,max-div = <2>;
};
clock-controller@a40 {
#clock-cells = <0>;
compatible = "ti,composite-divider-clock";
clocks = <&corex2_fck>;
ti,bit-shift = <8>;
reg = <0x0a40>;
ti,dividers = <0>, <1>, <2>, <3>, <4>, <0>, <6>, <0>, <8>;
};
};
|
