Changes between Version 37 and Version 38 of expansion/gw16130

Timestamp:

07/08/2020 06:47:52 PM (5 years ago)

Author:

Tim Harvey

Comment:

updated eeprom config with new default

expansion/gw16130

@@ -68 +68 @@
  * CBUS3: not connected
 
-By default the FTDI EEPROM is configured by gateworks such that all 4 of the CBUS pins are configured for IOMODE/GPIO mode which means that you need to enable CBUS0 gpio to enable the modem.
+By default (for all GW16130 boards manufactured after Jul 8, 2020) the FTDI EEPROM is configured by Gateworks such that CBUS0 is configured to always drive a logic high level (DRIVE1) to enable the modem at powerup and the other CBUS pins are configured as GPIO.
 
-'''Important''' Run the following to configure GPIO & enable the modem (requires a 4.20 kernel or newer) :
-{{{
+If you wish to be able to disable the modem you can use the {{{ftx_prog}}} utility to alter the EEPROM configuration for CBUS0 and make it a GPIO then use either Linux gpiolib (/sys/class/gpio) as shown below or some other means (such as an application using libftdi) to manipulate it. If you change CBUS0 to a GPIO the modem will by default be disabled (due to the 10k pull-down on that signal) until you configure the GPIO to output a logic high.
+
+The {{{ftx_prog}}} utility is an open source program that uses libftdi and can be easily built:
+{{{#!bash
+sudo apt-get install git build-essential gcc make libftdi-dev
+git clone https://github.com/richardeoin/ftx-prog.git
+cd ftx-prog
+make
+}}}
+
+The following commands are used to configure the FTDI EEPROM such that the CBUS0 is a GPIO:
+{{{#!bash
+sudo ./ftx_prog --cbus 0 GPIO # configure CBUS0 as GPIO
+}}}
+
+And if you want to re-configure it to change it back to Drive_1 to make the modem always enabled at power-up:
+{{{#!bash
+sudo ./ftx_prog --cbus 0 Drive_1 # configure CBUS0 as always output high
+}}}
+
+You will need to either power-cycle your board or reload the ftdi_sio kernel module to make this take effect:
+{{{#!bash
+rmmod ftdi_sio
+modprobe ftdi_sio
+}}}
+
+If CBUS0 is configured as GPIO you can use the following commands (on a 4.20 or newer kernel) to configure GPIO & enable the modem:
+{{{#!bash
 base=$(for i in $(ls -1d /sys/class/gpio/gpiochip*); do [ "ftdi-cbus" = "$(cat $i/label)" ] && cat $i/base; done)
 [ "$base" ] || { echo "Error: could not find ftdi-cbus device"; }
@@ -83 +109 @@
 }}}
 
-Note that exporting the gpio's above will fail if you have used something like {{{ftx_prog}}} (below) to re-configure the CBUS pins to a mode other than IOMODE/GPIO.
+Note that exporting the GPIO will fail if it was configured for 'Drive_1'.
 
-=== Procedure for kernels prior to Linux 4.20
-Because support for controlling the FTDI GPIOs was introduced in Kernel 4.20, a program (ftx_prog) can be used to configure the FTDI io-pins in the EEPROM on the FTDI chip on earlier kernels. Configuring CBUS0 as 'drive-1' makes it always output a logic high enabling the modem and removes the need (and ability) to manipulate the gpio to turn the modem on/off.
-
-This is an open source program located here: https://github.com/richardeoin/ftx-prog
-
-Building:
-{{{#!bash
-sudo apt-get install git build-essential gcc make libftdi-dev
-git clone https://github.com/richardeoin/ftx-prog.git
-cd ftx-prog
-make
-}}}
-
-The following commands are used to re-configure the CBUS0 pin to keep the modem always enabled:
-{{{#!bash
-sudo ./ftx_prog --cbus 0 Drive_1 # configure CBUS0 as always output high
-}}}
-
-And if you want to re-configure it to change it back to a GPIO (in which case you will need a Linux 4.20 kernel or newer or a userspace application to configure the ftdi-cbus gpio):
-{{{#!bash
-sudo ./ftx_prog --cbus 0 GPIO # configure CBUS0 as GPIO
-}}}
-
-Note: Power cycle board after running commands. 
 
 == Modem AT Commands