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Last Post 17 Sep 2007 10:26 AM by  davek
UARTB under Linux
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davek
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16 Jul 2007 05:25 PM
    Has anyone been able to use UARTB (/dev/ttymxc1) successfully under linux?

    Here's what I've been able to use:
    - UART A - works
    - UART B - doesn't work
    - UART C - works
    - UART D - overlaps with IDE pins - disabled
    - UART E - seems to be USB Host Pins

    More specifically, the UART B pins on the expansion board seem to be at the wrong logic levels. The TX pin should sit high, and it seems to be always low. Any suggestions? Thanks
    thehexa@gmail.com
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    20 Jul 2007 01:22 PM
    Posted By davek on 16 Jul 2007 5:25 PM
    Has anyone been able to use UARTB (/dev/ttymxc1) successfully under linux?

    Here''s what I''ve been able to use:
    - UART A - works
    - UART B - doesn''t work
    - UART C - works
    - UART D - overlaps with IDE pins - disabled
    - UART E - seems to be USB Host Pins

    More specifically, the UART B pins on the expansion board seem to be at the wrong logic levels. The TX pin should sit high, and it seems to be always low. Any suggestions? Thanks




    in the board-mx31lite.h UARTB is defined as an irda port. You should try editing that header with what u need.

    In another note, have u been able to use RTS/CTS/DSR etc pins in any of the uarts?

    regards
    davek
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    24 Jul 2007 11:07 AM
    Hi there. I have tried making changes to board-mx31lite.h already. It currently looks like:

    /* UART 2 configuration */
    #define UART2_MODE MODE_DTE /* DAVE: was DCE */
    #define UART2_IR NO_IRDA /* DAVE: was IRDA */
    #define UART2_ENABLED 1
    /* UART 3 configuration */
    #define UART3_MODE MODE_DTE
    #define UART3_IR NO_IRDA
    #define UART3_ENABLED 1
    /* UART 4 configuration */
    #define UART4_MODE MODE_DTE
    #define UART4_IR NO_IRDA
    #define UART4_ENABLED 0 /* Disable UART 4 as its pins are shared with ATA */
    /* UART 5 configuration */
    #define UART5_MODE MODE_DTE
    #define UART5_IR NO_IRDA
    #define UART5_ENABLED 1

    Making these changes had no effect. Any other suggestions? I haven't tried using the flow control pins, so I don't know if they work
    richh@logicpd.com
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    Posts:52


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    14 Sep 2007 10:49 AM
    David,
    Did you solve your problem? We found that in LOLO, the GPR at 0x43FAC008 is set as 0xd, but it should be 0xC to enable UART2. Try typing

    w /w 0x43FAC008 0xC

    at the LOLO prompt before starting your linux image.
    davek
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    17 Sep 2007 10:26 AM
    Hello,

    Thanks for your help. I tried it out, and that solved the problem. Wonderful! Thanks

    Dave
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