| # Copyright (c) 2023 Cypress Semiconductor Corporation (an Infineon company) or |
| # an affiliate of Cypress Semiconductor Corporation |
| # |
| # SPDX-License-Identifier: Apache-2.0 |
| |
| description: | |
| |
| Infineon XMC4XXX I2C |
| |
| This driver configures the USIC as an I2C device. |
| |
| Example devicetree configuration with an adt7420 temperature sensor |
| connected on the bus: |
| |
| &usic1ch1 { |
| compatible = "infineon,xmc4xxx-i2c"; |
| status = "okay"; |
| |
| pinctrl-0 = <&i2c_scl_p0_13_u1c1 &i2c_sda_p3_15_u1c1>; |
| pinctrl-names = "default"; |
| scl-src = "DX1B"; |
| sda-src = "DX0A"; |
| interrupts = <94 1>; |
| |
| #address-cells = <1>; |
| #size-cells = <0>; |
| |
| clock-frequency = <I2C_BITRATE_STANDARD>; |
| adt7420@48 { |
| compatible = "adi,adt7420"; |
| reg = <0x48>; |
| }; |
| }; |
| |
| The pinctrl nodes need to be configured as open-drain and |
| hwctrl should be disabled: |
| |
| &i2c_scl_p0_13_u1c1 { |
| drive-strength = "strong-sharp-edge"; |
| drive-open-drain; |
| hwctrl = "disabled"; |
| }; |
| |
| &i2c_sda_p3_15_u1c1 { |
| drive-strength = "strong-soft-edge"; |
| drive-open-drain; |
| hwctrl = "disabled"; |
| }; |
| |
| compatible: "infineon,xmc4xxx-i2c" |
| |
| include: [i2c-controller.yaml, pinctrl-device.yaml] |
| |
| properties: |
| reg: |
| type: array |
| required: true |
| |
| scl-src: |
| description: | |
| Connects the I2C clock line (USIC DX1 input) to a specific GPIO pin. |
| The USIC DX1 input is a multiplexer which connects to different GPIO pins. |
| Refer to the XMC4XXX reference manual for the GPIO pin/mux mappings. |
| type: string |
| required: true |
| enum: |
| - "DX1A" |
| - "DX1B" |
| - "DX1C" |
| - "DX1D" |
| - "DX1E" |
| - "DX1F" |
| - "DX1G" |
| |
| sda-src: |
| description: | |
| Connects the I2C data line (USIC DX0 input) to a specific GPIO pin. |
| The USIC DX0 input is a multiplexer which connects to different GPIO pins. |
| Refer to the XMC4XXX reference manual for the GPIO pin/mux mappings. |
| type: string |
| required: true |
| enum: |
| - "DX0A" |
| - "DX0B" |
| - "DX0C" |
| - "DX0D" |
| - "DX0E" |
| - "DX0F" |
| - "DX0G" |
| |
| interrupts: |
| required: true |
| description: | |
| IRQ number and priority to use for interrupt driven by I2C. |
| Each USIC must use a certain interrupt range: |
| USIC0 = [84, 89] |
| USIC1 = [90, 95] |
| USIC2 = [96, 101] |
| |
| pinctrl-0: |
| description: | |
| PORT pin configuration for SCL, SDA signals. |
| We expect that the phandles will reference pinctrl nodes. These |
| nodes will have a nodelabel that matches the Infineon SoC Pinctrl |
| defines and have following |
| format: i2c_<signal>_p<port>_<pin>_<peripheral inst> |
| |
| Examples: |
| pinctrl-0 = <&i2c_scl_p5_2_u2c0 &i2c_sda_p5_0_u2c0>; |
| |
| The pins should set to open-drain and hwctrl should be disabled. |
| |
| &i2c_scl_p5_2_u2c0 { |
| drive-strength = "strong-sharp-edge"; |
| drive-open-drain; |
| hwctrl = "disabled"; |
| }; |
| |
| In the above example, the pin is both an input and output (as is |
| required for I2C setup). It is internally connected to both DX0 |
| and DOUT0 of USIC2 channel 0. (See XMC4700/4800 reference manual |
| page 18-110, Figure 18-50 for more details). |
| This limits the number of pins that can be used for the I2C module. |
| |
| To get around this pin limitation, it is possible to use pins |
| that do not have this internal connection, and instead connect the |
| pins externally on the board. |
| For example, for the SDA line on USIC2 channel 0, P3.8 may be used |
| for DOUT0 and P6.5 for DX0. These type of pinctrl nodes will have |
| labels: |
| i2c_sda_dout0_p3_8_u2c0 and i2c_sda_dx0_p6_5_u2c0. |
| The generalized format is: i2c_<signal>_<type>_p<port>_<pin>_<peripheral inst> |
| |
| An example for SCL and SDA signals on the xmc4700: |
| pinctrl-0 = <&i2c_sda_dout0_p3_8_u2c0 &i2c_sda_dx0_p6_5_u2c0 |
| &i2c_scl_dout1_p3_9_u2c0 &i2c_scl_p5_2_u2c0>; |
| |
| Externally P3.8 should be connected to P6.5; P3.9 should be connected |
| to P5.2. |
| |
| Note that any pins that do not have dout0/dx0 or dout1/dx1 can have either |
| function. Thus node i2c_scl_p5_0_u2c0 can be both dout1 and dx1. |
| |
| For the pin configurations, the output pins (dout0 and dout1) should be set |
| to open-drain while the input pins (dx0 and dx1) should not include this setting. |
| |
| &i2c_sda_dout0_p3_8_u2c0 { |
| drive-strength = "strong-sharp-edge"; |
| drive-open-drain; |
| hwctrl = "disabled"; |
| }; |
| |
| &i2c_scl_dout1_p3_9_u2c0 { |
| drive-strength = "strong-sharp-edge"; |
| drive-open-drain; |
| hwctrl = "disabled"; |
| }; |
| |
| &i2c_sda_dx0_p6_5_u2c0 { /* will require USIC setting sda-src = DX0D */ |
| hwctrl = "disabled"; |
| }; |
| |
| &i2c_scl_p5_2_u2c0 { /* will require USIC scl-src = DX1A */ |
| hwctrl = "disabled"; |
| }; |
| |
| required: true |
| |
| pinctrl-names: |
| required: true |
