SNLA443 December   2023 DP83869HM

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1DP83869 Application Overview
  5. 2Troubleshooting the Application
    1. 2.1 Configuring Correct Operational Mode
    2. 2.2 Schematic and Layout Checklist
    3. 2.3 Component Checklist
    4. 2.4 Peripheral Pin Checks
      1. 2.4.1 Power Supplies
      2. 2.4.2 RBIAS Voltage and Resistance
      3. 2.4.3 Probe the XI Clock
      4. 2.4.4 Probe the RESET_N Signal
      5. 2.4.5 Probe the Strap Pins During Initialization
      6. 2.4.6 Probe the Serial Management Interface Signals (MDC, MDIO)
      7. 2.4.7 Probe the MDI Signals
    5. 2.5 Built-In Self Test with Various Loopback Modes
    6. 2.6 Debugging MAC Interface
      1. 2.6.1 RGMII
      2. 2.6.2 SGMII
  6. 3Operational Mode Clarification
    1. 3.1 Bridge Modes
    2. 3.2 Fiber Configuration
      1. 3.2.1 Fiber Registers
  7. 4Tools and References
    1. 4.1 DP83869HM Register Access
    2. 4.2 Extended Register Access
      1. 4.2.1 Read (No Post Increment) Operation
      2. 4.2.2 Write (No Post Increment) Operation
    3. 4.3 Software and Driver Debug on Linux
      1. 4.3.1 Common Terminal Outputs
  8. 5Summary
  9. 6References

4.3 Software and Driver Debug on Linux

The two essential components required for the PHY to function on a Linux system are the device tree and driver file, for which the DP83869HM drivers can be found here. Below is a sample format of what a device tree looks like. This can be found on any open source kernal under the following path: root/Documentation/devicetree/bindings/net/ti.

 #include <dt-bindings/net/ti-dp83869.h>
    mdio0 {
      #address-cells = <1>;
      #size-cells = <0>;
      ethphy0: ethernet-phy@0 {
        reg = <0>;
        tx-fifo-depth = <DP83869_PHYCR_FIFO_DEPTH_4_B_NIB>;
        rx-fifo-depth = <DP83869_PHYCR_FIFO_DEPTH_4_B_NIB>;
        ti,op-mode = <DP83869_RGMII_COPPER_ETHERNET>;
        ti,max-output-impedance;
        ti,clk-output-sel = <DP83869_CLK_O_SEL_CHN_A_RCLK>;
        rx-internal-delay-ps = <2000>;
        tx-internal-delay-ps = <2000>;
      };
    };