:orphan: .. _atmel_sam_i2c_twim: atmel,sam-i2c-twim ################## Vendor: :ref:`Atmel Corporation ` Description *********** These nodes are "i2c" bus nodes. .. code-block:: none Atmel SAM4L Family I2C (TWIM) node The Atmel Two-wire Master Interface (TWIM) interconnects components on a unique two-wire bus, made up of one clock line and one data line with speeds of up to 3.4 Mbit/s, based on a byte-oriented transfer format. The TWIM is always a bus master and can transfer sequential or single bytes. Multiple master capability is supported. Arbitration of the bus is performed internally and relinquishes the bus automatically if the bus arbitration is lost. When using speeds above standard mode, user may need adjust clock and data lines slew and strength parameters. In general, slew 0 and minimal strength is enougth for short buses and light loads. As reference, the below is the lowest power configuration: std-clk-slew-lim = <0>; std-clk-strength-low = "0.5"; std-data-slew-lim = <0>; std-data-strength-low = "0.5"; hs-clk-slew-lim = <0>; hs-clk-strength-high = "0.5"; hs-clk-strength-low = "0.5"; hs-data-slew-lim = <0>; hs-data-strength-low = "0.5"; For best performances, user can tune the slope curves using an osciloscope. The tuning should be performed by groups defined -. The prefix std- configures fast/fast-plus mode speeds and hs- selects the high speed mode. The tune should be performed for both clock and data lines on both speed modes. Properties ********** .. tabs:: .. group-tab:: Node specific properties Properties not inherited from the base binding file. .. list-table:: :widths: 1 1 4 :header-rows: 1 * - Name - Type - Details * - ``peripheral-id`` - ``int`` - .. code-block:: none peripheral ID This property is **required**. * - ``std-clk-slew-lim`` - ``int`` - .. code-block:: none Slew limit of the TWCK output buffer. This should be adjusted with std-clk-strength-low to fine tune the TWCK slope. This property is **required**. Legal values: ``0``, ``1``, ``2``, ``3`` * - ``std-clk-strength-low`` - ``string`` - .. code-block:: none Pull-down drive strength of the TWCK output buffer in fast/fast plus mode. This should be adjusted to provide proper TWCK line fall time. The value represents the port output current in mA when signal on low level. This property is **required**. Legal values: ``'0.5'``, ``'1.0'``, ``'1.6'``, ``'3.1'``, ``'6.2'``, ``'9.3'``, ``'15.5'``, ``'21.8'`` * - ``std-data-slew-lim`` - ``int`` - .. code-block:: none Slew limit of the TWD output buffer. This should be adjusted with std-data-strength-low to fine tune the TWD slope. This property is **required**. Legal values: ``0``, ``1``, ``2``, ``3`` * - ``std-data-strength-low`` - ``string`` - .. code-block:: none Pull-down drive strength of the TWD output buffer in fast/fast plus mode. This should be adjusted to provide proper TWD line fall time. The value represents the port output current in mA when signal on low level. This property is **required**. Legal values: ``'0.5'``, ``'1.0'``, ``'1.6'``, ``'3.1'``, ``'6.2'``, ``'9.3'``, ``'15.5'``, ``'21.8'`` * - ``hs-clk-slew-lim`` - ``int`` - .. code-block:: none Slew limit of the TWCK output buffer in high speed mode. This should be adjusted with both hs-clk-strength-high and hs-clk-strength-low to fine tune the TWCK slope. This property is **required**. Legal values: ``0``, ``1``, ``2``, ``3`` * - ``hs-clk-strength-high`` - ``string`` - .. code-block:: none Pull-up drive strength of the TWCK output buffer in high speed mode. This should be adjusted to provide proper TWCK line rise time. The value represents the port output current in mA when signal on high level. This property is **required**. Legal values: ``'0.5'``, ``'1.0'``, ``'1.5'``, ``'3.0'`` * - ``hs-clk-strength-low`` - ``string`` - .. code-block:: none Pull-down drive strength of the TWCK output buffer in high speed mode. This should be adjusted to provide proper TWCK line fall time. The value represents the port output current in mA when signal on low level. This property is **required**. Legal values: ``'0.5'``, ``'1.0'``, ``'1.6'``, ``'3.1'``, ``'6.2'``, ``'9.3'``, ``'15.5'``, ``'21.8'`` * - ``hs-data-slew-lim`` - ``int`` - .. code-block:: none Slew limit of the TWD output buffer in high speed mode. This should be adjusted with hs-data-strength-low to fine tune the TWD slope. This property is **required**. Legal values: ``0``, ``1``, ``2``, ``3`` * - ``hs-data-strength-low`` - ``string`` - .. code-block:: none Pull-down drive strength of the TWD output buffer in high speed mode. This should be adjusted to provide proper TWD line fall time. The value represents the port output current in mA when signal on low level. Legal values: ``'0.5'``, ``'1.0'``, ``'1.6'``, ``'3.1'``, ``'6.2'``, ``'9.3'``, ``'15.5'``, ``'21.8'`` * - ``hs-master-code`` - ``int`` - .. code-block:: none 3-bit code to be prefixed with 0b00001 to form a unique 8-bit HS-mode master code (0000 1XXX) This property is **required**. Legal values: ``0``, ``1``, ``2``, ``3``, ``4``, ``5``, ``6``, ``7`` * - ``pinctrl-0`` - ``phandles`` - .. code-block:: none GPIO pin configuration for TWCK & TWD signals. We expect that the phandles will reference pinctrl nodes. These nodes will have a nodelabel that matches the Atmel SoC HAL defines and be of the form p__. For example the I2C on SAM4L would be pinctrl-0 = <&pb0a_twi1_twd1 &pb1a_twi1_twck1>; This property is **required**. * - ``clock-frequency`` - ``int`` - .. code-block:: none Initial clock frequency in Hz .. group-tab:: Deprecated node specific properties Deprecated properties not inherited from the base binding file. (None) .. group-tab:: Base properties Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the "atmel,sam-i2c-twim" compatible. .. list-table:: :widths: 1 1 4 :header-rows: 1 * - Name - Type - Details * - ``reg`` - ``array`` - .. code-block:: none register space This property is **required**. See :ref:`dt-important-props` for more information. * - ``interrupts`` - ``array`` - .. code-block:: none interrupts for device This property is **required**. See :ref:`dt-important-props` for more information. * - ``#address-cells`` - ``int`` - .. code-block:: none number of address cells in reg property This property is **required**. Constant value: ``1`` * - ``#size-cells`` - ``int`` - .. code-block:: none number of size cells in reg property This property is **required**. * - ``label`` - ``string`` - .. code-block:: none Human readable string describing the device (used as device_get_binding() argument) This property is **required**. See :ref:`dt-important-props` for more information. * - ``status`` - ``string`` - .. code-block:: none indicates the operational status of a device Legal values: ``'ok'``, ``'okay'``, ``'disabled'``, ``'reserved'``, ``'fail'``, ``'fail-sss'`` See :ref:`dt-important-props` for more information. * - ``compatible`` - ``string-array`` - .. code-block:: none compatible strings This property is **required**. See :ref:`dt-important-props` for more information. * - ``reg-names`` - ``string-array`` - .. code-block:: none name of each register space * - ``interrupts-extended`` - ``compound`` - .. code-block:: none extended interrupt specifier for device * - ``interrupt-names`` - ``string-array`` - .. code-block:: none name of each interrupt * - ``interrupt-parent`` - ``phandle`` - .. code-block:: none phandle to interrupt controller node * - ``clocks`` - ``phandle-array`` - .. code-block:: none Clock gate information * - ``clock-names`` - ``string-array`` - .. code-block:: none name of each clock * - ``dmas`` - ``phandle-array`` - .. code-block:: none DMA channels specifiers * - ``dma-names`` - ``string-array`` - .. code-block:: none Provided names of DMA channel specifiers * - ``io-channels`` - ``phandle-array`` - .. code-block:: none IO channels specifiers * - ``io-channel-names`` - ``string-array`` - .. code-block:: none Provided names of IO channel specifiers