1 files changed, 97 insertions, 0 deletions
diff --git a/src/detection/gamepad/gamepad_linux.c b/src/detection/gamepad/gamepad_linux.c
new file mode 100644
index 0000000..6bb4ee2
--- /dev/null
+++ b/src/detection/gamepad/gamepad_linux.c
@@ -0,0 +1,97 @@
+#include "gamepad.h"
+#include "common/io.h"
+#include "common/strutil.h"
+
+static void detectGamepad(FFlist* devices, FFstrbuf* name, FFstrbuf* path) {
+    uint32_t baseLen = path->length;
+    FFGamepadDevice* device = FF_LIST_ADD(FFGamepadDevice, *devices);
+    ffStrbufInit(&device->serial);
+    ffStrbufInitMove(&device->name, name);
+    device->battery = 0;
+
+    ffStrbufAppendS(path, "uniq");
+    if (ffAppendFileBuffer(path->chars, &device->serial)) {
+        ffStrbufTrimRightSpace(&device->serial);
+    }
+
+    ffStrbufSubstrBefore(path, baseLen);
+    ffStrbufAppendS(path, "device/power_supply/"); // /sys/class/input/jsX/device/device/power_supply
+
+    FF_AUTO_CLOSE_DIR DIR* dirp = opendir(path->chars);
+    if (dirp) {
+        struct dirent* entry;
+        while ((entry = readdir(dirp)) != NULL) {
+            if (entry->d_name[0] == '.' || (entry->d_type != DT_DIR && entry->d_type != DT_UNKNOWN)) {
+                continue;
+            }
+            ffStrbufAppendS(path, entry->d_name);
+            ffStrbufAppendS(path, "/capacity"); // /sys/class/input/jsX/device/device/power_supply/XXX/capacity
+            char capacity[32];
+            ssize_t nRead = ffReadFileData(path->chars, ARRAY_SIZE(capacity) - 1, capacity);
+            if (nRead > 0) // Tested with a PS4 controller
+            {
+                capacity[nRead] = '\0';
+                device->battery = (uint8_t) strtoul(capacity, NULL, 10);
+                break;
+            }
+
+            ffStrbufAppendS(path, "_level");
+            nRead = ffReadFileData(path->chars, ARRAY_SIZE(capacity) - 1, capacity);
+            if (nRead > 0) // Tested with a NS Pro controller
+            {
+                // https://github.com/torvalds/linux/blob/52b1853b080a082ec3749c3a9577f6c71b1d4a90/drivers/power/supply/power_supply_sysfs.c#L124
+                switch (capacity[0]) {
+                    case 'C':
+                        device->battery = 1;
+                        break; // Critical
+                    case 'L':
+                        device->battery = 25;
+                        break; // Low
+                    case 'N':
+                        device->battery = 50;
+                        break; // Normal
+                    case 'H':
+                        device->battery = 75;
+                        break; // High
+                    case 'F':
+                        device->battery = 100;
+                        break; // Full
+                }
+            }
+        }
+    }
+}
+
+const char* ffDetectGamepad(FFlist* devices /* List of FFGamepadDevice */) {
+    FF_AUTO_CLOSE_DIR DIR* dirp = opendir("/sys/class/input/");
+    if (dirp == NULL) {
+        return "opendir(\"/sys/class/input/\") == NULL";
+    }
+
+    FF_STRBUF_AUTO_DESTROY path = ffStrbufCreateS("/sys/class/input/");
+    uint32_t baseLen = path.length;
+
+    struct dirent* entry;
+    while ((entry = readdir(dirp)) != NULL) {
+        if (!ffStrStartsWith(entry->d_name, "js")) {
+            continue;
+        }
+        if (!ffCharIsDigit(entry->d_name[strlen("js")])) {
+            continue;
+        }
+
+        ffStrbufAppendS(&path, entry->d_name);
+        ffStrbufAppendS(&path, "/device/name");
+
+        FF_STRBUF_AUTO_DESTROY name = ffStrbufCreate();
+        if (ffAppendFileBuffer(path.chars, &name)) {
+            ffStrbufTrimRightSpace(&name);
+            ffStrbufSubstrBefore(&path, path.length - 4);
+            detectGamepad(devices, &name, &path);
+        }
+
+        ffStrbufSubstrBefore(&path, baseLen);
+    }
+
+    return NULL;
+}