* [libgpiod][PATCH] tools: gpioget: add new --dir-as-is option for GPO read-back
@ 2021-04-27 15:42 Ahmad Fatoum
2021-04-30 20:02 ` Bartosz Golaszewski
0 siblings, 1 reply; 2+ messages in thread
From: Ahmad Fatoum @ 2021-04-27 15:42 UTC (permalink / raw)
To: Linus Walleij, Bartosz Golaszewski, linux-gpio; +Cc: kernel, Ahmad Fatoum
Both legacy sysfs and new character device API support querying line
state of a GPIO configured as output. But while sysfs /value can
be read for these output GPIOs, gpioget unconditionally muxes the
line as input. To ease migration to the new user API, add a new
--dir-as-is parameter that doesn't force the line to input.
This is especially useful for GPIO controllers that maintain their
last configured output state.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
-n is chosen for the short option because it's the customary short
option for dry runs, which sounds similar to what a gpio get without
line state configuration is doing.
---
tools/gpioget.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/tools/gpioget.c b/tools/gpioget.c
index ceeec566683a..bfbf5ea748be 100644
--- a/tools/gpioget.c
+++ b/tools/gpioget.c
@@ -13,11 +13,12 @@ static const struct option longopts[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'v' },
{ "active-low", no_argument, NULL, 'l' },
+ { "dir-as-is", no_argument, NULL, 'n' },
{ "bias", required_argument, NULL, 'B' },
{ GETOPT_NULL_LONGOPT },
};
-static const char *const shortopts = "+hvlB:";
+static const char *const shortopts = "+hvlnB:";
static void print_help(void)
{
@@ -30,6 +31,7 @@ static void print_help(void)
printf(" -h, --help:\t\tdisplay this message and exit\n");
printf(" -v, --version:\tdisplay the version and exit\n");
printf(" -l, --active-low:\tset the line active state to low\n");
+ printf(" -n, --dir-as-is:\tdon't force-reconfigure line direction\n");
printf(" -B, --bias=[as-is|disable|pull-down|pull-up] (defaults to 'as-is'):\n");
printf(" set the line bias\n");
printf("\n");
@@ -40,6 +42,7 @@ int main(int argc, char **argv)
{
struct gpiod_line_request_config config;
int *values, optc, opti, rv, flags = 0;
+ int request_type = GPIOD_LINE_REQUEST_DIRECTION_INPUT;
unsigned int *offsets, i, num_lines;
struct gpiod_line_bulk *lines;
struct gpiod_chip *chip;
@@ -60,6 +63,9 @@ int main(int argc, char **argv)
case 'l':
flags |= GPIOD_LINE_REQUEST_FLAG_ACTIVE_LOW;
break;
+ case 'n':
+ request_type = GPIOD_LINE_REQUEST_DIRECTION_AS_IS;
+ break;
case 'B':
flags |= bias_flags(optarg);
break;
@@ -104,7 +110,7 @@ int main(int argc, char **argv)
memset(&config, 0, sizeof(config));
config.consumer = "gpioget";
- config.request_type = GPIOD_LINE_REQUEST_DIRECTION_INPUT;
+ config.request_type = request_type;
config.flags = flags;
rv = gpiod_line_request_bulk(lines, &config, NULL);
--
2.29.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [libgpiod][PATCH] tools: gpioget: add new --dir-as-is option for GPO read-back
2021-04-27 15:42 [libgpiod][PATCH] tools: gpioget: add new --dir-as-is option for GPO read-back Ahmad Fatoum
@ 2021-04-30 20:02 ` Bartosz Golaszewski
0 siblings, 0 replies; 2+ messages in thread
From: Bartosz Golaszewski @ 2021-04-30 20:02 UTC (permalink / raw)
To: Ahmad Fatoum; +Cc: Linus Walleij, linux-gpio, Sascha Hauer
On Tue, Apr 27, 2021 at 5:42 PM Ahmad Fatoum <a.fatoum@pengutronix.de> wrote:
>
> Both legacy sysfs and new character device API support querying line
> state of a GPIO configured as output. But while sysfs /value can
> be read for these output GPIOs, gpioget unconditionally muxes the
> line as input. To ease migration to the new user API, add a new
> --dir-as-is parameter that doesn't force the line to input.
>
> This is especially useful for GPIO controllers that maintain their
> last configured output state.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
> -n is chosen for the short option because it's the customary short
> option for dry runs, which sounds similar to what a gpio get without
> line state configuration is doing.
> ---
> tools/gpioget.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/tools/gpioget.c b/tools/gpioget.c
> index ceeec566683a..bfbf5ea748be 100644
> --- a/tools/gpioget.c
> +++ b/tools/gpioget.c
> @@ -13,11 +13,12 @@ static const struct option longopts[] = {
> { "help", no_argument, NULL, 'h' },
> { "version", no_argument, NULL, 'v' },
> { "active-low", no_argument, NULL, 'l' },
> + { "dir-as-is", no_argument, NULL, 'n' },
> { "bias", required_argument, NULL, 'B' },
> { GETOPT_NULL_LONGOPT },
> };
>
> -static const char *const shortopts = "+hvlB:";
> +static const char *const shortopts = "+hvlnB:";
>
> static void print_help(void)
> {
> @@ -30,6 +31,7 @@ static void print_help(void)
> printf(" -h, --help:\t\tdisplay this message and exit\n");
> printf(" -v, --version:\tdisplay the version and exit\n");
> printf(" -l, --active-low:\tset the line active state to low\n");
> + printf(" -n, --dir-as-is:\tdon't force-reconfigure line direction\n");
> printf(" -B, --bias=[as-is|disable|pull-down|pull-up] (defaults to 'as-is'):\n");
> printf(" set the line bias\n");
> printf("\n");
> @@ -40,6 +42,7 @@ int main(int argc, char **argv)
> {
> struct gpiod_line_request_config config;
> int *values, optc, opti, rv, flags = 0;
> + int request_type = GPIOD_LINE_REQUEST_DIRECTION_INPUT;
> unsigned int *offsets, i, num_lines;
> struct gpiod_line_bulk *lines;
> struct gpiod_chip *chip;
> @@ -60,6 +63,9 @@ int main(int argc, char **argv)
> case 'l':
> flags |= GPIOD_LINE_REQUEST_FLAG_ACTIVE_LOW;
> break;
> + case 'n':
> + request_type = GPIOD_LINE_REQUEST_DIRECTION_AS_IS;
> + break;
> case 'B':
> flags |= bias_flags(optarg);
> break;
> @@ -104,7 +110,7 @@ int main(int argc, char **argv)
> memset(&config, 0, sizeof(config));
>
> config.consumer = "gpioget";
> - config.request_type = GPIOD_LINE_REQUEST_DIRECTION_INPUT;
> + config.request_type = request_type;
> config.flags = flags;
>
> rv = gpiod_line_request_bulk(lines, &config, NULL);
> --
> 2.29.2
>
Makes sense, applied to master.
It'll take some time until this is released though, libgpiod v2 is in
the making and I no longer add new features to the v1.6.x branch
anymore.
Thanks!
Bartosz
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