gpioget: allow reading multiple lines at once

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>

diff --git a/src/tools/gpioget.c b/src/tools/gpioget.c
index e0f20a480876a870d6b42e63b554941ef747ab02..ce64030375551b214f668c8117c849755c77245a 100644 (file)
--- a/src/tools/gpioget.c
+++ b/src/tools/gpioget.c
@@ -14,6 +14,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <getopt.h>
+#include <limits.h>
 
 static const struct option longopts[] = {
        { "help",       no_argument,    NULL,   'h' },
@@ -26,9 +27,9 @@ static const char *const shortopts = "+hvl";
 
 static void print_help(void)
 {
-       printf("Usage: %s [OPTIONS] <chip name/number> <line offset>\n",
+       printf("Usage: %s [OPTIONS] <chip name/number> <offset 1> <offset 2> ...\n",
               get_progname());
-       printf("Read value from a GPIO line\n");
+       printf("Read line value(s) from a GPIO chip\n");
        printf("Options:\n");
        printf("  -h, --help:\t\tdisplay this message and exit\n");
        printf("  -v, --version:\tdisplay the version and exit\n");
@@ -37,9 +38,9 @@ static void print_help(void)
 
 int main(int argc, char **argv)
 {
+       unsigned int *offsets, i, num_lines;
+       int *values, optc, opti, status;
        bool active_low = false;
-       int value, optc, opti;
-       unsigned int offset;
        char *device, *end;
 
        set_progname(argv[0]);
@@ -73,19 +74,36 @@ int main(int argc, char **argv)
                die("gpiochip must be specified");
 
        if (argc < 2)
-               die("gpio line offset must be specified");
+               die("at least one gpio line offset must be specified");
 
        device = argv[0];
+       num_lines = argc - 1;
 
-       offset = strtoul(argv[1], &end, 10);
-       if (*end != '\0')
-               die("invalid GPIO offset: %s", argv[1]);
+       values = malloc(sizeof(*values) * num_lines);
+       offsets = malloc(sizeof(*offsets) * num_lines);
+       if (!values || !offsets)
+               die("out of memory");
 
-       value = gpiod_simple_get_value(device, offset, active_low);
-       if (value < 0)
-               die_perror("error reading GPIO value");
+       for (i = 0; i < num_lines; i++) {
+               offsets[i] = strtoul(argv[i + 1], &end, 10);
+               if (*end != '\0' || offsets[i] > INT_MAX)
+                       die("invalid GPIO offset: %s", argv[i + 1]);
+       }
+
+       status = gpiod_simple_get_value_multiple(device, offsets, values,
+                                                num_lines, active_low);
+       if (status < 0)
+               die_perror("error reading GPIO values");
+
+       for (i = 0; i < num_lines; i++) {
+               printf("%d", values[i]);
+               if (i != num_lines - 1)
+                       printf(" ");
+       }
+       printf("\n");
 
-       printf("%d\n", value);
+       free(values);
+       free(offsets);
 
        return EXIT_SUCCESS;
 }