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diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt deleted file mode 100644 index fc3dd7ec04..0000000000 --- a/Documentation/devicetree/bindings/i2c/i2c.txt +++ /dev/null @@ -1,151 +0,0 @@ -Generic device tree bindings for I2C busses -=========================================== - -This document describes generic bindings which can be used to describe I2C -busses and their child devices in a device tree. - -Required properties (per bus) ------------------------------ - -- #address-cells - should be <1>. Read more about addresses below. -- #size-cells - should be <0>. -- compatible - name of I2C bus controller - -For other required properties e.g. to describe register sets, -clocks, etc. check the binding documentation of the specific driver. - -The cells properties above define that an address of children of an I2C bus -are described by a single value. - -Optional properties (per bus) ------------------------------ - -These properties may not be supported by all drivers. However, if a driver -wants to support one of the below features, it should adapt these bindings. - -- clock-frequency - frequency of bus clock in Hz. - -- i2c-bus - For I2C adapters that have child nodes that are a mixture of both I2C - devices and non-I2C devices, the 'i2c-bus' subnode can be used for - populating I2C devices. If the 'i2c-bus' subnode is present, only - subnodes of this will be considered as I2C slaves. The properties, - '#address-cells' and '#size-cells' must be defined under this subnode - if present. - -- i2c-scl-falling-time-ns - Number of nanoseconds the SCL signal takes to fall; t(f) in the I2C - specification. - -- i2c-scl-internal-delay-ns - Number of nanoseconds the IP core additionally needs to setup SCL. - -- i2c-scl-rising-time-ns - Number of nanoseconds the SCL signal takes to rise; t(r) in the I2C - specification. - -- i2c-sda-falling-time-ns - Number of nanoseconds the SDA signal takes to fall; t(f) in the I2C - specification. - -- i2c-analog-filter - Enable analog filter for i2c lines. - -- i2c-digital-filter - Enable digital filter for i2c lines. - -- i2c-digital-filter-width-ns - Width of spikes which can be filtered by digital filter - (i2c-digital-filter). This width is specified in nanoseconds. - -- i2c-analog-filter-cutoff-frequency - Frequency that the analog filter (i2c-analog-filter) uses to distinguish - which signal to filter. Signal with higher frequency than specified will - be filtered out. Only lower frequency will pass (this is applicable to - a low-pass analog filter). Typical value should be above the normal - i2c bus clock frequency (clock-frequency). - Specified in Hz. - -- multi-master - states that there is another master active on this bus. The OS can use - this information to adapt power management to keep the arbitration awake - all the time, for example. Can not be combined with 'single-master'. - -- pinctrl - add extra pinctrl to configure SCL/SDA pins to GPIO function for bus - recovery, call it "gpio" or "recovery" (deprecated) state - -- scl-gpios - specify the gpio related to SCL pin. Used for GPIO bus recovery. - -- sda-gpios - specify the gpio related to SDA pin. Optional for GPIO bus recovery. - -- single-master - states that there is no other master active on this bus. The OS can use - this information to detect a stalled bus more reliably, for example. - Can not be combined with 'multi-master'. - -- smbus - states that additional SMBus restrictions and features apply to this bus. - An example of feature is SMBusHostNotify. Examples of restrictions are - more reserved addresses and timeout definitions. - -- smbus-alert - states that the optional SMBus-Alert feature apply to this bus. - -- mctp-controller - indicates that the system is accessible via this bus as an endpoint for - MCTP over I2C transport. - -Required properties (per child device) --------------------------------------- - -- compatible - name of I2C slave device - -- reg - One or many I2C slave addresses. These are usually a 7 bit addresses. - However, flags can be attached to an address. I2C_TEN_BIT_ADDRESS is - used to mark a 10 bit address. It is needed to avoid the ambiguity - between e.g. a 7 bit address of 0x50 and a 10 bit address of 0x050 - which, in theory, can be on the same bus. - Another flag is I2C_OWN_SLAVE_ADDRESS to mark addresses on which we - listen to be devices ourselves. - -Optional properties (per child device) --------------------------------------- - -These properties may not be supported by all drivers. However, if a driver -wants to support one of the below features, it should adapt these bindings. - -- host-notify - device uses SMBus host notify protocol instead of interrupt line. - -- interrupts - interrupts used by the device. - -- interrupt-names - "irq", "wakeup" and "smbus_alert" names are recognized by I2C core, - other names are left to individual drivers. - -- reg-names - Names of map programmable addresses. - It can contain any map needing another address than default one. - -- wakeup-source - device can be used as a wakeup source. - -Binding may contain optional "interrupts" property, describing interrupts -used by the device. I2C core will assign "irq" interrupt (or the very first -interrupt if not using interrupt names) as primary interrupt for the slave. - -Alternatively, devices supporting SMBus Host Notify, and connected to -adapters that support this feature, may use "host-notify" property. I2C -core will create a virtual interrupt for Host Notify and assign it as -primary interrupt for the slave. - -Also, if device is marked as a wakeup source, I2C core will set up "wakeup" -interrupt for the device. If "wakeup" interrupt name is not present in the -binding, then primary interrupt will be used as wakeup interrupt. |