181 lines
5.8 KiB
YAML
181 lines
5.8 KiB
YAML
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
|
|
%YAML 1.2
|
|
---
|
|
$id: http://devicetree.org/schemas/i3c/i3c.yaml#
|
|
$schema: http://devicetree.org/meta-schemas/core.yaml#
|
|
|
|
title: I3C bus binding
|
|
|
|
maintainers:
|
|
- Alexandre Belloni <alexandre.belloni@bootlin.com>
|
|
- Miquel Raynal <miquel.raynal@bootlin.com>
|
|
|
|
description: |
|
|
I3C busses can be described with a node for the primary I3C controller device
|
|
and a set of child nodes for each I2C or I3C slave on the bus. Each of them
|
|
may, during the life of the bus, request mastership.
|
|
|
|
properties:
|
|
$nodename:
|
|
pattern: "^i3c-master@[0-9a-f]+$"
|
|
|
|
"#address-cells":
|
|
const: 3
|
|
description: |
|
|
Each I2C device connected to the bus should be described in a subnode.
|
|
|
|
All I3C devices are supposed to support DAA (Dynamic Address Assignment),
|
|
and are thus discoverable. So, by default, I3C devices do not have to be
|
|
described in the device tree. This being said, one might want to attach
|
|
extra resources to these devices, and those resources may have to be
|
|
described in the device tree, which in turn means we have to describe
|
|
I3C devices.
|
|
|
|
Another use case for describing an I3C device in the device tree is when
|
|
this I3C device has a static I2C address and we want to assign it a
|
|
specific I3C dynamic address before the DAA takes place (so that other
|
|
devices on the bus can't take this dynamic address).
|
|
|
|
"#size-cells":
|
|
const: 0
|
|
|
|
i3c-scl-hz:
|
|
description: |
|
|
Frequency of the SCL signal used for I3C transfers. When undefined, the
|
|
default value should be 12.5MHz.
|
|
|
|
May not be supported by all controllers.
|
|
|
|
i2c-scl-hz:
|
|
description: |
|
|
Frequency of the SCL signal used for I2C transfers. When undefined, the
|
|
default should be to look at LVR (Legacy Virtual Register) values of
|
|
I2C devices described in the device tree to determine the maximum I2C
|
|
frequency.
|
|
|
|
May not be supported by all controllers.
|
|
|
|
required:
|
|
- "#address-cells"
|
|
- "#size-cells"
|
|
|
|
patternProperties:
|
|
"@[0-9a-f]+$":
|
|
type: object
|
|
description: |
|
|
I2C child, should be named: <device-type>@<i2c-address>
|
|
|
|
All properties described in Documentation/devicetree/bindings/i2c/i2c.txt
|
|
are valid here, except the reg property whose content is changed.
|
|
|
|
properties:
|
|
compatible:
|
|
description:
|
|
Compatible of the I2C device.
|
|
|
|
reg:
|
|
items:
|
|
- items:
|
|
- description: |
|
|
I2C address. 10 bit addressing is not supported. Devices with
|
|
10-bit address can't be properly passed through DEFSLVS
|
|
command.
|
|
minimum: 0
|
|
maximum: 0x7f
|
|
- const: 0
|
|
- description: |
|
|
Shall encode the I3C LVR (Legacy Virtual Register):
|
|
bit[31:8]: unused/ignored
|
|
bit[7:5]: I2C device index. Possible values:
|
|
* 0: I2C device has a 50 ns spike filter
|
|
* 1: I2C device does not have a 50 ns spike filter but
|
|
supports high frequency on SCL
|
|
* 2: I2C device does not have a 50 ns spike filter and is
|
|
not tolerant to high frequencies
|
|
* 3-7: reserved
|
|
bit[4]: tell whether the device operates in FM (Fast Mode)
|
|
or FM+ mode:
|
|
* 0: FM+ mode
|
|
* 1: FM mode
|
|
bit[3:0]: device type
|
|
* 0-15: reserved
|
|
|
|
required:
|
|
- compatible
|
|
- reg
|
|
|
|
"@[0-9a-f]+,[0-9a-f]+$":
|
|
type: object
|
|
description: |
|
|
I3C child, should be named: <device-type>@<static-i2c-address>,<i3c-pid>
|
|
|
|
properties:
|
|
reg:
|
|
items:
|
|
- items:
|
|
- description: |
|
|
Encodes the static I2C address. Should be 0 if the device does
|
|
not have one (0 is not a valid I2C address).
|
|
minimum: 0
|
|
maximum: 0x7f
|
|
- description: |
|
|
First half of the Provisional ID (following the PID
|
|
definition provided by the I3C specification).
|
|
|
|
Contains the manufacturer ID left-shifted by 1.
|
|
- description: |
|
|
Second half of the Provisional ID (following the PID
|
|
definition provided by the I3C specification).
|
|
|
|
Contains the ORing of the part ID left-shifted by 16,
|
|
the instance ID left-shifted by 12 and extra information.
|
|
|
|
assigned-address:
|
|
$ref: /schemas/types.yaml#/definitions/uint32
|
|
minimum: 0x1
|
|
maximum: 0xff
|
|
description: |
|
|
Dynamic address to be assigned to this device. This property is only
|
|
valid if the I3C device has a static address (first cell of the reg
|
|
property != 0).
|
|
|
|
required:
|
|
- reg
|
|
|
|
additionalProperties: true
|
|
|
|
examples:
|
|
- |
|
|
i3c-master@d040000 {
|
|
compatible = "cdns,i3c-master";
|
|
clocks = <&coreclock>, <&i3csysclock>;
|
|
clock-names = "pclk", "sysclk";
|
|
interrupts = <3 0>;
|
|
reg = <0x0d040000 0x1000>;
|
|
#address-cells = <3>;
|
|
#size-cells = <0>;
|
|
i2c-scl-hz = <100000>;
|
|
|
|
/* I2C device. */
|
|
eeprom@57 {
|
|
compatible = "atmel,24c01";
|
|
reg = <0x57 0x0 0x10>;
|
|
pagesize = <0x8>;
|
|
};
|
|
|
|
/* I3C device with a static I2C address. */
|
|
thermal_sensor: sensor@68,39200144004 {
|
|
reg = <0x68 0x392 0x144004>;
|
|
assigned-address = <0xa>;
|
|
};
|
|
|
|
/*
|
|
* I3C device without a static I2C address but requiring
|
|
* resources described in the DT.
|
|
*/
|
|
sensor@0,39200154004 {
|
|
reg = <0x0 0x392 0x154004>;
|
|
clocks = <&clock_provider 0>;
|
|
};
|
|
};
|