interesting
/
riscv-openocd
mirror of https://github.com/riscv/riscv-openocd.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Steve Marple 2022-05-01 22:29:43 +01:00 committed by Antonio Borneo
parent dac90163a2
commit 62cea61237
1 changed files with 78 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

79
doc/openocd.texi
View File

@ -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