On Thu, Jan 14, 2021 at 06:55:53PM +0100, Miquel Raynal wrote: > Attempting a conversion of the i3c.txt file to yaml schema with > minimal content changes. > > Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> > --- > Documentation/devicetree/bindings/i3c/i3c.txt | 140 ------------- > .../devicetree/bindings/i3c/i3c.yaml | 186 ++++++++++++++++++ > 2 files changed, 186 insertions(+), 140 deletions(-) > delete mode 100644 Documentation/devicetree/bindings/i3c/i3c.txt > create mode 100644 Documentation/devicetree/bindings/i3c/i3c.yaml > diff --git a/Documentation/devicetree/bindings/i3c/i3c.yaml b/Documentation/devicetree/bindings/i3c/i3c.yaml > new file mode 100644 > index 000000000000..79df533ab094 > --- /dev/null > +++ b/Documentation/devicetree/bindings/i3c/i3c.yaml > @@ -0,0 +1,186 @@ > +# 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@xxxxxxxxxxx> > + - Miquel Raynal <miquel.raynal@xxxxxxxxxxx> > + > +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: > + $ref: /schemas/types.yaml#/definitions/uint32 With a unit suffix, you don't need the type. > + 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: > + $ref: /schemas/types.yaml#/definitions/uint32 > + description: | > + Frequency of the SCL signal used for I2C transfers. When undefined, the > + default should be to look at LVR (Legacy Virtual Register) values of > + I2C devices described in the device tree to determine the maximum I2C > + frequency. > + > + May not be supported by all controllers. > + > +required: > + - "#address-cells" > + - "#size-cells" > + > +patternProperties: > + "^.*@[0-9a-f]+$": You can drop '^.*': "@[0-9a-f]+$" > + type: object > + description: | > + I2C child, should be named: <device-type>@<i2c-address> > + > + All properties described in Documentation/devicetree/bindings/i2c/i2c.txt > + are valid here, except the reg property whose content is changed. > + > + properties: > + compatible: > + description: > + Compatible of the I2C device. > + > + reg: > + items: > + - description: | > + 1st cell > + ======== > + > + I2C address. 10 bit addressing is not supported. Devices with > + 10-bit address can't be properly passed through DEFSLVS command. > + > + 2nd cell > + ======== > + > + Should be 0. > + > + 3rd cell > + ======== > + > + Shall encode the I3C LVR (Legacy Virtual Register): > + bit[31:8]: unused/ignored > + bit[7:5]: I2C device index. Possible values: > + * 0: I2C device has a 50 ns spike filter > + * 1: I2C device does not have a 50 ns spike filter but supports > + high frequency on SCL > + * 2: I2C device does not have a 50 ns spike filter and is not > + tolerant to high frequencies > + * 3-7: reserved > + bit[4]: tell whether the device operates in FM (Fast Mode) or > + FM+ mode: > + * 0: FM+ mode > + * 1: FM mode > + bit[3:0]: device type > + * 0-15: reserved We can do a bit better: reg: items: - items: # Note: drop the '-' if we support more than 1 entry - description: I2C address... maximum: 0x7f # Not sure this works, do we support the high # flag bits here? - const: 0 - description: I3C LVR (Legacy Virtual Register)... > + > + required: > + - compatible > + - reg > + > + "^.*@[0-9a-f]+,[0-9a-f]+$": > + type: object > + description: | > + I3C child, should be named: <device-type>@<static-i2c-address>,<i3c-pid> > + > + properties: > + reg: > + items: > + - description: | > + 1st cell > + ======== > + > + Encodes the static I2C address. Should be 0 if the device does not > + have one (0 is not a valid I2C address). > + > + 2nd and 3rd cells > + ================= > + > + ProvisionalID (following the PID definition provided by the I3C > + specification). > + > + Cell 2 contains the manufacturer ID left-shifted by 1. Cell 3 > + contains the ORing of the part ID left-shifted by 16, the instance > + ID left-shifted by 12 and extra information. Similar rework here. > + > + assigned-address: > + $ref: /schemas/types.yaml#/definitions/uint32 > + minimum: 0x01 > + 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>; > + }; > + }; > -- > 2.20.1 >
