doc: Document linuxgpiod driver commands

Change-Id: I84ad5dba9ab2099137595b46822bc10a0b089524
Signed-off-by: Steve Marple <stevemarple@googlemail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6962
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

1 files changed, 78 insertions, 1 deletions

diff --git a/doc/openocd.texi b/doc/openocd.texi
index 9681cf5..be9e5ac 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -3419,9 +3419,86 @@ speed_coeff defaults to 600000 and speed_offset defaults to 575.
 
 @deffn {Interface Driver} {linuxgpiod}
 Linux provides userspace access to GPIO through libgpiod since Linux kernel version v4.6.
-The driver emulates either JTAG and SWD transport through bitbanging.
+The driver emulates either JTAG or SWD transport through bitbanging.
 
 See @file{interface/dln-2-gpiod.cfg} for a sample config.
+
+@deffn {Config Command} {linuxgpiod gpiochip} @var{chip}
+Set the GPIO chip number for all GPIOs used by linuxgpiod. If GPIOs use
+different GPIO chips then the individual GPIO configuration commands (i.e., not
+@command{linuxgpiod jtag_nums} or @command{linuxgpiod swd_nums}) can be used to
+set chip numbers independently for each GPIO.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod jtag_nums} @var{tck} @var{tms} @var{tdi} @var{tdo}
+Set JTAG transport GPIO numbers for TCK, TMS, TDI, and TDO (in that order). Must
+be specified to enable JTAG transport. These pins can also be specified
+individually.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod tck_num} [@var{chip}] @var{tck}
+Set TCK GPIO number, and optionally TCK chip number. Must be specified to enable
+JTAG transport. Can also be specified using the configuration command
+@command{linuxgpiod jtag_nums}.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod tms_num} [@var{chip}] @var{tms}
+Set TMS GPIO number, and optionally TMS chip number. Must be specified to enable
+JTAG transport. Can also be specified using the configuration command
+@command{linuxgpiod jtag_nums}.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod tdo_num} [@var{chip}] @var{tdo}
+Set TDO GPIO number, and optionally TDO chip number. Must be specified to enable
+JTAG transport. Can also be specified using the configuration command
+@command{linuxgpiod jtag_nums}.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod tdi_num} [@var{chip}] @var{tdi}
+Set TDI GPIO number, and optionally TDI chip number. Must be specified to enable
+JTAG transport. Can also be specified using the configuration command
+@command{linuxgpiod jtag_nums}.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod trst_num} [@var{chip}] @var{trst}
+Set TRST GPIO number, and optionally TRST chip number. Must be specified to
+enable TRST.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod swd_nums} @var{swclk} @var{swdio}
+Set SWD transport GPIO numbers for SWCLK and SWDIO (in that order). Must be
+specified to enable SWD transport. These pins can also be specified
+individually.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod swclk_num} [@var{chip}] @var{swclk}
+Set SWCLK GPIO number, and optionally SWCLK chip number. Must be specified to
+enable SWD transport. Can also be specified using the configuration command
+@command{linuxgpiod swd_nums}.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod swdio_num} [@var{chip}] @var{swdio}
+Set SWDIO GPIO number, and optionally SWDIO chip number. Must be specified to
+enable SWD transport. Can also be specified using the configuration command
+@command{linuxgpiod swd_nums}.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod swdio_dir_num} [@var{chip}] @var{swdio_dir}
+Set SWDIO direction control GPIO number, and optionally SWDIO direction control
+chip number. If specified, this GPIO can be used to control the direction of an
+external buffer connected to the SWDIO GPIO (set=output mode, clear=input mode).
+@end deffn
+
+@deffn {Config Command} {linuxgpiod srst_num} [@var{chip}] @var{srst}
+Set SRST GPIO number, and optionally SRST chip number. Must be specified to
+enable SRST.
+@end deffn
+
+@deffn {Config Command} {linuxgpiod led_num} [@var{chip}] @var{led}
+Set activity LED GPIO number, and optionally activity LED chip number. If not
+specified an activity LED is not enabled.
+@end deffn
+
 @end deffn