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74 lines
2.4 KiB
Plaintext
74 lines
2.4 KiB
Plaintext
How to configure modem support in U-Boot :
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1. Define modem initialization strings:
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---------------------------------------
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The modem initialization strings have following format:
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mdm_init1=<AT-command>
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mdm_init2=<AT-command>
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...
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Turning off modem verbose responses with ATV0 or ATQ1 is not allowed;
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U-Boot analyzes only verbose (not numeric) result codes. Modem local
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command echo can be turned off (ATE0).
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2. RTS/CTS hardware flow control:
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---------------------------------
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You may wish to enable RTS/CTS hardware flow control, if the board's
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UART driver supports it (see CONFIG_HWFLOW compile-time flag in
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config/<board>.h). This is controlled by the 'mdm_flow_control'
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environment variable:
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'mdm_flow_control=rts/cts' - to enable RTS/CTS flow control.
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'mdm_flow_control=none ' - to disable.
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The following are the examples using a Rockwell OEM modem
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configuration:
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SAMSUNG # setenv mdm_init1 ATZ - reset the modem to
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the factory defaults.
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SAMSUNG # setenv mdm_init2 ATS0=1 - set modem into
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answer mode.
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SAMSUNG # setenv mdm_flow_control rts/cts - enable serial port
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flow control
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SAMSUNG # saveenv
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The example above initializes modem into answer mode to wait for the
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incoming call. RTS/CTS flow control is enabled for the serial port.
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(The RTS/CTS flow control is enabled by default on the modem).
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SAMSUNG # setenv mdm_init1 ATZ
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SAMSUNG # setenv mdm_init2 ATS39=0+IFC=0,0 - disable modem
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RTS/CTS flow control
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SAMSUNG # setenv mdm_init3 ATDT1643973 - dial out the number
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SAMSUNG # setenv mdm_flow_control none
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SAMSUNG # saveenv
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The example above initializes modem to dial-up connection on the
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number 1643973. Flow control is disabled.
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Note that flow control must be turned both off or both on for the
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board serial port and for the modem.
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If the connection was set up successfully, the U-Boot prompt appears
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on the terminal console. If not (U-Boot modem was configured for
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originating the call and connection was not established) - the board
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should be reset for another dial-up try.
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Note on the SMDK2400 board:
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---------------------------
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Since the board serial ports does not have DTR signal wired, modem
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should be told to ignore port DTR setting prior to connection to the
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SMDK board, and this setting should be stored in modem NVRAM. For the
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Rockwell OEM modem this can to be done with the following command:
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AT&D0&W
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