+Some adapters require that the GPIO chip number is set in addition to the GPIO
+number. The configuration options enable signals to be defined as active-high or
+active-low. The output drive mode can be set to push-pull, open-drain or
+open-source. Most adapters will have to emulate open-drain or open-source drive
+modes by switching between an input and output. Input and output signals can be
+instructed to use a pull-up or pull-down resistor, assuming it is supported by
+the adaptor driver and hardware. The initial state of outputs may also be set,
+"active" state means 1 for active-high outputs and 0 for active-low outputs.
+Bidirectional signals may also be initialized as an input. If the swdio signal
+is buffered the buffer direction can be controlled with the swdio_dir signal;
+the active state means that the buffer should be set as an output with respect
+to the adapter. The command options are cumulative with later commands able to
+override settings defined by earlier ones. The two commands @command{gpio led 7
+-active-high} and @command{gpio led -chip 1 -active-low} sent sequentially are
+equivalent to issuing the single command @command{gpio led 7 -chip 1
+-active-low}. It is not permissible to set the drive mode or initial state for
+signals which are inputs. The drive mode for the srst and trst signals must be
+set with the @command{adapter reset_config} command. It is not permissible to
+set the initial state of swdio_dir as it is derived from the initial state of
+swdio. The command @command{adapter gpio} prints the current configuration for
+all GPIOs while the command @command{adapter gpio gpio_name} prints the current
+configuration for gpio_name. Not all adapters support this generic GPIO mapping,
+some require their own commands to define the GPIOs used. Adapters that support
+the generic mapping may not support all of the listed options.
+@end deffn