linux-zen-desktop/Documentation/devicetree/bindings/spi/brcm,bcm63xx-hsspi.yaml

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2023-08-30 17:31:07 +02:00
# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/spi/brcm,bcm63xx-hsspi.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Broadcom Broadband SoC High Speed SPI controller
maintainers:
- William Zhang <william.zhang@broadcom.com>
- Kursad Oney <kursad.oney@broadcom.com>
- Jonas Gorski <jonas.gorski@gmail.com>
description: |
Broadcom Broadband SoC supports High Speed SPI master controller since the
early MIPS based chips such as BCM6328 and BCM63268. This initial rev 1.0
controller was carried over to recent ARM based chips, such as BCM63138,
BCM4908 and BCM6858. The old MIPS based chip should continue to use the
brcm,bcm6328-hsspi compatible string. The recent ARM based chip is required to
use the brcm,bcmbca-hsspi-v1.0 as part of its compatible string list as
defined below to match the specific chip along with ip revision info.
This rev 1.0 controller has a limitation that can not keep the chip select line
active between the SPI transfers within the same SPI message. This can
terminate the transaction to some SPI devices prematurely. The issue can be
worked around by either the controller's prepend mode or using the dummy chip
select workaround. Driver automatically picks the suitable mode based on
transfer type so it is transparent to the user.
The newer SoCs such as BCM6756, BCM4912 and BCM6855 include an updated SPI
controller rev 1.1 that add the capability to allow the driver to control chip
select explicitly. This solves the issue in the old controller.
properties:
compatible:
oneOf:
- const: brcm,bcm6328-hsspi
- items:
- enum:
- brcm,bcm47622-hsspi
- brcm,bcm4908-hsspi
- brcm,bcm63138-hsspi
- brcm,bcm63146-hsspi
- brcm,bcm63148-hsspi
- brcm,bcm63158-hsspi
- brcm,bcm63178-hsspi
- brcm,bcm6846-hsspi
- brcm,bcm6856-hsspi
- brcm,bcm6858-hsspi
- brcm,bcm6878-hsspi
- const: brcm,bcmbca-hsspi-v1.0
- items:
- enum:
- brcm,bcm4912-hsspi
- brcm,bcm6756-hsspi
- brcm,bcm6813-hsspi
- brcm,bcm6855-hsspi
- const: brcm,bcmbca-hsspi-v1.1
reg:
items:
- description: main registers
- description: miscellaneous control registers
minItems: 1
reg-names:
items:
- const: hsspi
- const: spim-ctrl
minItems: 1
clocks:
items:
- description: SPI master reference clock
- description: SPI master pll clock
clock-names:
items:
- const: hsspi
- const: pll
interrupts:
maxItems: 1
required:
- compatible
- reg
- clocks
- clock-names
- interrupts
allOf:
- $ref: spi-controller.yaml#
- if:
properties:
compatible:
contains:
enum:
- brcm,bcm6328-hsspi
- brcm,bcmbca-hsspi-v1.0
then:
properties:
reg:
maxItems: 1
reg-names:
maxItems: 1
else:
properties:
reg:
minItems: 2
maxItems: 2
reg-names:
minItems: 2
maxItems: 2
required:
- reg-names
unevaluatedProperties: false
examples:
- |
#include <dt-bindings/interrupt-controller/arm-gic.h>
spi@ff801000 {
compatible = "brcm,bcm6756-hsspi", "brcm,bcmbca-hsspi-v1.1";
reg = <0xff801000 0x1000>,
<0xff802610 0x4>;
reg-names = "hsspi", "spim-ctrl";
interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&hsspi>, <&hsspi_pll>;
clock-names = "hsspi", "pll";
num-cs = <8>;
#address-cells = <1>;
#size-cells = <0>;
};