Changes between Version 14 and Version 15 of canbus


Ignore:
Timestamp:
09/12/2022 09:56:29 PM (20 months ago)
Author:
Tim Harvey
Comment:

updated GPIO STBY pin configuration notes

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  • canbus

    v14 v15  
    6767|| ||
    6868|| Ventana  || GW551x+GW16111 || IMX6 || flexcan || N/A || N/A || ^^^2^^^ ||
    69 ||          || GW54xx    || IMX6 / [http://dev.gateworks.com/datasheets/MCP2562.pdf MCP2562] || flexcan || R123 (not loaded) || GPIO1_IO02 / gpio-2 || ||
    70 ||          || GW53xx    || IMX6 / [http://dev.gateworks.com/datasheets/MCP2562.pdf MCP2562] || flexcan || R50 (not loaded) || GPIO1_IO02 / gpio-2 || ||
    71 ||          || GW52xx    || IMX6 / [http://dev.gateworks.com/datasheets/MCP2562.pdf MCP2562] || flexcan || R168 (not loaded) || GPIO1_IO09 / gpio-9 || ||
    72 
     69||          || GW54xx    || IMX6 / [http://dev.gateworks.com/datasheets/MCP2562.pdf MCP2562] || flexcan || GPIO1_IO02 / gpio-2 || R123 (not loaded) || ^^^4^^^ ||
     70||          || GW53xx    || IMX6 / [http://dev.gateworks.com/datasheets/MCP2562.pdf MCP2562] || flexcan || GPIO1_IO02 / gpio-2 || R50 (not loaded) || ^^^4^^^ ||
     71||          || GW52xx    || IMX6 / [http://dev.gateworks.com/datasheets/MCP2562.pdf MCP2562] || flexcan || GPIO1_IO09 / gpio-9 || R168 (not loaded) || ^^^4^^^ ||
    7372
    7473 1. The Newport product family uses the MCP25625 CAN over SPI device thus the spi--thunderx (SPI_THUNDERX) driver is required in addition to the mcp251x (CAN_MCP251X) driver. Also, note the Thunderx SPI controller only supports half-duplex transactions requiring a patch to the mcp251x driver to make it operating as half-duplex: [https://github.com/Gateworks/linux-newport/commit/f284504b771b8741222ac54fd2d773d88e53de39 can: mcp251x: convert driver to half-duplex SPI]
    7574 2. The GW551x does not have a transceiver on board; CAN_RXD / CAN_TXD go to application connector
    7675 3. A Mini-PCIe expansion card may be used. See the [#minipcie Mini-PCIe] section at the end of this wiki page.
     76 4. On newer kernels this is configured via device-tree and thus manual gpio manipulation (described below) is not necessary
    7777
    7878Note the Termination resistor options in the table above and remember that a properly terminated CAN network will have 120ohm termination across CAN_L and CAN_H at each end of the bus for a total measured resistance of 60ohm.
    … …  
    8383[=#stby]
    8484=== CAN Transceiver STBY
    85 For boards that have a CAN STBY signal connected to a GPIO, the signal must be driven high to enable CAN:
     85For boards that have a CAN STBY signal connected to a GPIO and an older kernel where this is not configured in the device-tree and thus not handled automatically by the drivers, the signal must be driven LOW to enable CAN:
    8686 * For example on a GW53xx/GW54xx which use GPIO1_I02:
    8787{{{