gpio: libgpiod 2.0: port gpiod_chip_open_by_label

src/gpio.c

@@ -8,6 +8,8 @@
 #include "gpio.h"
 
 #include <unistd.h>
+#include <dirent.h>
+#include <sys/stat.h>
 
 /* Those defines are used for legacy config files only */
 #define GPIO_CHIP1_LABEL "1c20800.pinctrl"
@@ -133,6 +135,90 @@ struct gpiod_line *gpio_get_input_line(struct EG25Manager *manager, int chip, in
     return gpio_line;
 }
 
+static int gpio_chip_dir_filter(const struct dirent *entry)
+{
+    struct stat sb;
+    int ret = 0;
+    char *path;
+
+    if (asprintf(&path, "/dev/%s", entry->d_name) < 0)
+        return 0;
+
+    if ((lstat(path, &sb) == 0) && (!S_ISLNK(sb.st_mode)) &&
+        gpiod_is_gpiochip_device(path))
+        ret = 1;
+
+    free(path);
+
+    return ret;
+}
+
+int gpio_all_chip_paths(char ***paths_ptr)
+{
+    int i, j, num_chips, ret = 0;
+    struct dirent **entries;
+    char **paths;
+
+    num_chips = scandir("/dev/", &entries, gpio_chip_dir_filter, alphasort);
+    if (num_chips < 0)
+        g_error("gpio: unable to scan /dev: %s", g_strerror(errno));
+
+    paths = calloc(num_chips, sizeof(*paths));
+    if (paths == NULL)
+        g_error("gpio: out of memory");
+
+    for (i = 0; i < num_chips; i++) {
+        if (asprintf(&paths[i], "/dev/%s", entries[i]->d_name) < 0) {
+            for (j = 0; j < i; j++)
+                free(paths[j]);
+
+            free(paths);
+            return 0;
+        }
+    }
+
+    *paths_ptr = paths;
+    ret = num_chips;
+
+    for (i = 0; i < num_chips; i++)
+        free(entries[i]);
+
+    free(entries);
+    return ret;
+}
+
+struct gpiod_chip *gpio_chip_open_by_label(const char *label)
+{
+    int num_chips, i;
+    char **paths;
+    const char *clabel;
+    struct gpiod_chip *chip;
+    struct gpiod_chip_info *cinfo;
+
+    num_chips = gpio_all_chip_paths(&paths);
+
+    for (i = 0; i < num_chips; i++) {
+        chip = gpiod_chip_open(paths[i]);
+        if (!chip)
+            continue;
+
+        cinfo = gpiod_chip_get_info(chip);
+        if (!cinfo)
+            goto clean_chip_open;
+
+        clabel = gpiod_chip_info_get_label(cinfo);
+
+        if (strcmp(label, clabel) == 0) {
+            return chip;
+        }
+
+clean_chip_open:
+        gpiod_chip_close(chip);
+    }
+
+    return NULL;
+}
+
 int gpio_init(struct EG25Manager *manager, toml_table_t *config[])
 {
     int i;
@@ -169,7 +255,7 @@ int gpio_init(struct EG25Manager *manager, toml_table_t *config[])
             toml_datum_t data = toml_string_at(chipslist, i);
             if (!data.ok)
                 continue;
-            manager->gpiochip[i] = gpiod_chip_open_by_label(data.u.s);
+            manager->gpiochip[i] = gpio_chip_open_by_label(data.u.s);
             if (!manager->gpiochip[i])
                 g_error("Unable to find GPIO chip '%s'", data.u.s);
         }
@@ -220,11 +306,11 @@ int gpio_init(struct EG25Manager *manager, toml_table_t *config[])
         guint offset, chipidx, gpio_idx;
 
         /* Legacy config file, only used on the OG PinePhone */
-        manager->gpiochip[0] = gpiod_chip_open_by_label(GPIO_CHIP1_LABEL);
+        manager->gpiochip[0] = gpio_chip_open_by_label(GPIO_CHIP1_LABEL);
         if (!manager->gpiochip[0])
             g_error("Unable to open GPIO chip " GPIO_CHIP1_LABEL);
 
-        manager->gpiochip[1] = gpiod_chip_open_by_label(GPIO_CHIP2_LABEL);
+        manager->gpiochip[1] = gpio_chip_open_by_label(GPIO_CHIP2_LABEL);
         if (!manager->gpiochip[1])
             g_error("Unable to open GPIO chip " GPIO_CHIP2_LABEL);