[libgpiod][PATCH v4 16/20] tools: gpioset: add support for drive flags

[Kent Gibson <warthog618@gmail.com>]

Add support for drive flags to gpioset so that line drive flags
(open-drain,open-source) can be set from the command line.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
 tools/gpioset.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/tools/gpioset.c b/tools/gpioset.c
index 347fb2e..610ff75 100644
--- a/tools/gpioset.c
+++ b/tools/gpioset.c
@@ -24,6 +24,7 @@ static const struct option longopts[] = {
 	{ "version",		no_argument,		NULL,	'v' },
 	{ "active-low",		no_argument,		NULL,	'l' },
 	{ "bias",		required_argument,	NULL,	'B' },
+	{ "drive",		required_argument,	NULL,	'D' },
 	{ "mode",		required_argument,	NULL,	'm' },
 	{ "sec",		required_argument,	NULL,	's' },
 	{ "usec",		required_argument,	NULL,	'u' },
@@ -31,7 +32,7 @@ static const struct option longopts[] = {
 	{ GETOPT_NULL_LONGOPT },
 };
 
-static const char *const shortopts = "+hvlB:m:s:u:b";
+static const char *const shortopts = "+hvlB:D:m:s:u:b";
 
 static void print_help(void)
 {
@@ -45,6 +46,8 @@ static void print_help(void)
 	printf("  -l, --active-low:\tset the line active state to low\n");
 	printf("  -B, --bias=[as-is|disable|pull-down|pull-up] (defaults to 'as-is'):\n");
 	printf("		set the line bias\n");
+	printf("  -D, --drive=[push-pull|open-drain|open-source] (defaults to 'push-pull'):\n");
+	printf("		set the line drive mode\n");
 	printf("  -m, --mode=[exit|wait|time|signal] (defaults to 'exit'):\n");
 	printf("		tell the program what to do after setting values\n");
 	printf("  -s, --sec=SEC:\tspecify the number of seconds to wait (only valid for --mode=time)\n");
@@ -53,6 +56,11 @@ static void print_help(void)
 	printf("\n");
 	print_bias_help();
 	printf("\n");
+	printf("Drives:\n");
+	printf("  push-pull:\tdrive the line both high and low\n");
+	printf("  open-drain:\tdrive the line low or go high impedance\n");
+	printf("  open-source:\tdrive the line high or go high impedance\n");
+	printf("\n");
 	printf("Modes:\n");
 	printf("  exit:\t\tset values and exit immediately\n");
 	printf("  wait:\t\tset values and wait for user to press ENTER\n");
@@ -183,6 +191,17 @@ static const struct mode_mapping *parse_mode(const char *mode)
 	return NULL;
 }
 
+static int drive_flags(const char *option)
+{
+	if (strcmp(option, "open-drain") == 0)
+		return GPIOD_CTXLESS_FLAG_OPEN_DRAIN;
+	if (strcmp(option, "open-source") == 0)
+		return GPIOD_CTXLESS_FLAG_OPEN_SOURCE;
+	if (strcmp(option, "push-pull") != 0)
+		die("invalid drive: %s", option);
+	return 0;
+}
+
 int main(int argc, char **argv)
 {
 	const struct mode_mapping *mode = &modes[MODE_EXIT];
@@ -212,6 +231,9 @@ int main(int argc, char **argv)
 		case 'B':
 			flags |= bias_flags(optarg);
 			break;
+		case 'D':
+			flags |= drive_flags(optarg);
+			break;
 		case 'm':
 			mode = parse_mode(optarg);
 			if (!mode)
-- 
2.24.0