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Diffstat (limited to 'dts/Bindings/i3c/i3c.txt')
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diff --git a/dts/Bindings/i3c/i3c.txt b/dts/Bindings/i3c/i3c.txt deleted file mode 100644 index 4ffe059f0f..0000000000 --- a/dts/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>; - }; - }; |