linux-zen-desktop/Documentation/devicetree/bindings/clock/renesas,rcar-usb2-clock-sel...

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YAML

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/clock/renesas,rcar-usb2-clock-sel.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Renesas R-Car USB 2.0 clock selector
maintainers:
- Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
description: |
If you connect an external clock to the USB_EXTAL pin only, you should set
the clock rate to "usb_extal" node only.
If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module
is not needed because this is default setting. (Of course, you can set the
clock rates to both "usb_extal" and "usb_xtal" nodes.
Case 1: An external clock connects to R-Car SoC
+----------+ +--- R-Car ---------------------+
|External |---|USB_EXTAL ---> all usb channels|
|clock | |USB_XTAL |
+----------+ +-------------------------------+
In this case, we need this driver with "usb_extal" clock.
Case 2: An oscillator connects to R-Car SoC
+----------+ +--- R-Car ---------------------+
|Oscillator|---|USB_EXTAL -+-> all usb channels|
| |---|USB_XTAL --+ |
+----------+ +-------------------------------+
In this case, we don't need this selector.
properties:
compatible:
items:
- enum:
- renesas,r8a774a1-rcar-usb2-clock-sel # RZ/G2M
- renesas,r8a774b1-rcar-usb2-clock-sel # RZ/G2N
- renesas,r8a774e1-rcar-usb2-clock-sel # RZ/G2H
- renesas,r8a7795-rcar-usb2-clock-sel # R-Car H3
- renesas,r8a7796-rcar-usb2-clock-sel # R-Car M3-W
- renesas,r8a77961-rcar-usb2-clock-sel # R-Car M3-W+
- const: renesas,rcar-gen3-usb2-clock-sel
reg:
maxItems: 1
clocks:
maxItems: 4
clock-names:
items:
- const: ehci_ohci
- const: hs-usb-if
- const: usb_extal
- const: usb_xtal
'#clock-cells':
const: 0
power-domains:
maxItems: 1
resets:
maxItems: 2
reset-names:
items:
- const: ehci_ohci
- const: hs-usb-if
required:
- compatible
- reg
- clocks
- clock-names
- '#clock-cells'
- power-domains
- resets
- reset-names
additionalProperties: false
examples:
- |
#include <dt-bindings/clock/r8a7795-cpg-mssr.h>
#include <dt-bindings/power/r8a7795-sysc.h>
usb2_clksel: clock-controller@e6590630 {
compatible = "renesas,r8a7795-rcar-usb2-clock-sel",
"renesas,rcar-gen3-usb2-clock-sel";
reg = <0xe6590630 0x02>;
clocks = <&cpg CPG_MOD 703>, <&cpg CPG_MOD 704>,
<&usb_extal>, <&usb_xtal>;
clock-names = "ehci_ohci", "hs-usb-if", "usb_extal", "usb_xtal";
#clock-cells = <0>;
power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;
resets = <&cpg 703>, <&cpg 704>;
reset-names = "ehci_ohci", "hs-usb-if";
};