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author | Miquel Raynal <miquel.raynal@bootlin.com> | 2021-01-21 13:18:03 +0300 |
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committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2021-02-06 02:43:29 +0300 |
commit | 5e4cdca887fdb445f962b3dbc2a2514d7c025d9b (patch) | |
tree | c8f1473801c0e09bbdc145fc1da98e99ecab620b /Documentation/devicetree/bindings | |
parent | dd9267034c0e364b49261c3e0070b863286d1242 (diff) | |
download | linux-5e4cdca887fdb445f962b3dbc2a2514d7c025d9b.tar.xz |
dt-bindings: i3c: Convert the bus description to yaml
Attempting a conversion of the i3c.txt file to yaml schema with
minimal content changes.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210121101808.14654-2-miquel.raynal@bootlin.com
Diffstat (limited to 'Documentation/devicetree/bindings')
-rw-r--r-- | Documentation/devicetree/bindings/i3c/i3c.txt | 140 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/i3c/i3c.yaml | 179 |
2 files changed, 179 insertions, 140 deletions
diff --git a/Documentation/devicetree/bindings/i3c/i3c.txt b/Documentation/devicetree/bindings/i3c/i3c.txt deleted file mode 100644 index 4ffe059f0fec..000000000000 --- a/Documentation/devicetree/bindings/i3c/i3c.txt +++ /dev/null @@ -1,140 +0,0 @@ -Generic device tree bindings for I3C busses -=========================================== - -This document describes generic bindings that should be used to describe I3C -busses in a device tree. - -Required properties -------------------- - -- #address-cells - should be <3>. Read more about addresses below. -- #size-cells - should be <0>. -- compatible - name of the I3C master controller driving the I3C bus - -For other required properties e.g. to describe register sets, -clocks, etc. check the binding documentation of the specific driver. -The node describing an I3C bus should be named i3c-master. - -Optional properties -------------------- - -These properties may not be supported by all I3C master drivers. Each I3C -master bindings should specify which of them are supported. - -- i3c-scl-hz: frequency of the SCL signal used for I3C transfers. - When undefined the core sets it to 12.5MHz. - -- i2c-scl-hz: frequency of the SCL signal used for I2C transfers. - When undefined, the core looks at LVR (Legacy Virtual Register) - values of I2C devices described in the device tree to determine - the maximum I2C frequency. - -I2C devices -=========== - -Each I2C device connected to the bus should be described in a subnode. All -properties described in Documentation/devicetree/bindings/i2c/i2c.txt are -valid here, but several new properties have been added. - -New constraint on existing properties: --------------------------------------- -- reg: contains 3 cells - + first cell : still encoding the I2C address. 10 bit addressing is not - supported. Devices with 10 bit address can't be properly passed through - DEFSLVS command. - - + second cell: shall be 0 - - + third cell: 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 - -The I2C node unit-address should always match the first cell of the reg -property: <device-type>@<i2c-address>. - -I3C devices -=========== - -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). - -The I3C device should be names <device-type>@<static-i2c-address>,<i3c-pid>, -where device-type is describing the type of device connected on the bus -(gpio-controller, sensor, ...). - -Required properties -------------------- -- reg: contains 3 cells - + first cell : encodes the static I2C address. Should be 0 if the device does - not have one (0 is not a valid I2C address). - - + second and third cells: should encode the ProvisionalID. The second cell - contains the manufacturer ID left-shifted by 1. - The third cell contains ORing of the part ID - left-shifted by 16, the instance ID left-shifted - by 12 and the extra information. This encoding is - following the PID definition provided by the I3C - specification. - -Optional properties -------------------- -- assigned-address: 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). - - -Example: - - 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. */ - nunchuk: nunchuk@52 { - compatible = "nintendo,nunchuk"; - reg = <0x52 0x0 0x10>; - }; - - /* 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>; - }; - }; diff --git a/Documentation/devicetree/bindings/i3c/i3c.yaml b/Documentation/devicetree/bindings/i3c/i3c.yaml new file mode 100644 index 000000000000..52042aa44d19 --- /dev/null +++ b/Documentation/devicetree/bindings/i3c/i3c.yaml @@ -0,0 +1,179 @@ +# 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. */ + nunchuk: nunchuk@52 { + compatible = "nintendo,nunchuk"; + reg = <0x52 0x0 0x10>; + }; + + /* 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>; + }; + }; |