From a8cff314204d6893c014dd5ca65322683f1407e9 Mon Sep 17 00:00:00 2001
From: Tony Jansson <tony@pihaus.org>
Date: Sun, 5 Jun 2022 08:27:41 +0300
Subject: [PATCH] (X11) Add LED keyboard driver

---
 Makefile.common                |   4 +
 led/drivers/led_x11_keyboard.c | 156 +++++++++++++++++++++++++++++++++
 led/led_driver.c               |   2 +-
 3 files changed, 161 insertions(+), 1 deletion(-)
 create mode 100644 led/drivers/led_x11_keyboard.c

diff --git a/Makefile.common b/Makefile.common
index 6a07e0c9b0..c0f8d82581 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -2434,6 +2434,10 @@ ifneq ($(findstring Win32,$(OS)),)
    OBJ += led/drivers/led_win32_keyboard.o
 endif
 
+ifeq ($(HAVE_X11), 1)
+   OBJ += led/drivers/led_x11_keyboard.o
+endif
+
 ifeq ($(HAVE_VITAGLES), 1)
    DEFINES += -DHAVE_VITAGLES
    INCLUDE_DIRS += -I$(DEPS_DIR)/Pigs-In-A-Blanket/include
diff --git a/led/drivers/led_x11_keyboard.c b/led/drivers/led_x11_keyboard.c
new file mode 100644
index 0000000000..a36bed799d
--- /dev/null
+++ b/led/drivers/led_x11_keyboard.c
@@ -0,0 +1,156 @@
+#include <stdio.h>
+#include "../led_driver.h"
+#include "../led_defines.h"
+
+#include "../../configuration.h"
+#include "../../retroarch.h"
+
+#include <X11/Xlib.h>
+#include <X11/XKBlib.h>
+
+/* Keys when setting in XKeyboardControl.led */
+#define XK_NUMLOCK    2
+#define XK_CAPSLOCK   1
+#define XK_SCROLLLOCK 3
+
+/* Keys when reading from XKeyboardState.led_mask */
+#define XM_NUMLOCK    2
+#define XM_CAPSLOCK   1
+#define XM_SCROLLLOCK 4
+
+static void key_translate(int *key)
+{
+   switch (*key)
+   {
+      case 0:
+         *key = XK_NUMLOCK;
+         break;
+      case 1:
+         *key = XK_CAPSLOCK;
+         break;
+      case 2:
+         *key = XK_SCROLLLOCK;
+         break;
+      default:
+         *key = 0;
+         break;
+   }
+}
+
+typedef struct
+{
+   int setup[MAX_LEDS];
+   int state[MAX_LEDS];
+   int map[MAX_LEDS];
+   bool init;
+} keyboard_led_t;
+
+/* TODO/FIXME - static globals */
+static keyboard_led_t x11kb_curins;
+static keyboard_led_t *x11kb_cur = &x11kb_curins;
+
+static int get_led(int led)
+{
+   Display *dpy = XOpenDisplay(0);
+   XKeyboardState state;
+   XGetKeyboardControl(dpy, &state);
+   XCloseDisplay(dpy);
+
+   switch (led)
+   {
+      case XK_NUMLOCK:
+         return (state.led_mask & XM_NUMLOCK) ? 1 : 0;
+         break;
+      case XK_CAPSLOCK:
+         return (state.led_mask & XM_CAPSLOCK) ? 1 : 0;
+         break;
+      case XK_SCROLLLOCK:
+         return (state.led_mask & XM_SCROLLLOCK) ? 1 : 0;
+         break;
+      default:
+         break;
+   }
+   return 0;
+}
+
+static void set_led(int led, int state)
+{
+   Display *dpy = XOpenDisplay(0);
+   XKeyboardControl values;
+   values.led = led;
+   values.led_mode = state ? LedModeOn : LedModeOff;
+   XChangeKeyboardControl(dpy, KBLed | KBLedMode, &values);
+   XCloseDisplay(dpy);
+}
+
+static int keyboard_led(int led, int state)
+{
+   int status = 0;
+   int key    = led;
+
+   if ((led < 0) || (led >= MAX_LEDS))
+      return -1;
+
+   key_translate(&key);
+   if (!key)
+      return -1;
+
+   status = get_led(key);
+
+   if (state == -1)
+      return status;
+
+   if ((state && !status) ||
+       (!state && status))
+   {
+      set_led(key, state);
+      x11kb_cur->state[led] = state;
+   }
+   return -1;
+}
+
+static void keyboard_init(void)
+{
+   int i;
+   settings_t *settings = config_get_ptr();
+
+   if (!settings || x11kb_cur->init)
+      return;
+
+   for (i = 0; i < MAX_LEDS; i++)
+   {
+      x11kb_cur->setup[i] = keyboard_led(i, -1);
+      x11kb_cur->state[i] = -1;
+      x11kb_cur->map[i]   = settings->uints.led_map[i];
+      if (x11kb_cur->map[i] < 0)
+         x11kb_cur->map[i] = i;
+   }
+   x11kb_cur->init = true;
+}
+
+static void keyboard_free(void)
+{
+   int i;
+
+   for (i = 0; i < MAX_LEDS; i++)
+   {
+      if (x11kb_cur->state[i] != -1 &&
+          x11kb_cur->state[i] != x11kb_cur->setup[i])
+         keyboard_led(i, x11kb_cur->setup[i]);
+   }
+}
+
+static void keyboard_set(int led, int state)
+{
+   if ((led < 0) || (led >= MAX_LEDS))
+      return;
+
+   keyboard_led(x11kb_cur->map[led], state);
+}
+
+const led_driver_t keyboard_led_driver = {
+   keyboard_init,
+   keyboard_free,
+   keyboard_set,
+   "Keyboard"
+};
diff --git a/led/led_driver.c b/led/led_driver.c
index d2dfbbe9d5..c7a6987d1c 100644
--- a/led/led_driver.c
+++ b/led/led_driver.c
@@ -49,7 +49,7 @@ void led_driver_init(const char *led_driver)
       current_led_driver  = &rpi_led_driver;
 #endif
 
-#if defined(_WIN32) && !defined(_XBOX) && !defined(__WINRT__)
+#if (defined(_WIN32) && !defined(_XBOX) && !defined(__WINRT__)) || defined(HAVE_X11)
    if (string_is_equal("keyboard", drivername))
       current_led_driver  = &keyboard_led_driver;
 #endif