wsdisplay: disable keyboard backlight with screen burner

[Tobias Heider]

Hi,

the diff below disables and restores the keyboard backlight together with
the screen on idle timeout to save a bit of battery.

ok?

diff 848795b17df6d7aac8fe7242132657e294ce39df 
0bb6b11cdeac4d4755e336594acf830b859e9d34
commit - 848795b17df6d7aac8fe7242132657e294ce39df
commit + 0bb6b11cdeac4d4755e336594acf830b859e9d34
blob - a0a3fd25717cce5888c4488c8fc8f35a5e43afe3
blob + bb5bb0ae7c868750c9f598a5bf6ef1142ab2942a
--- sys/dev/wscons/wsdisplay.c
+++ sys/dev/wscons/wsdisplay.c
@@ -156,6 +156,11 @@ struct wsdisplay_softc {
 void   wsdisplay_burner_setup(struct wsdisplay_softc *, struct wsscreen *);
 void   wsdisplay_burner(void *v);
 
+extern int (*wskbd_get_backlight)(struct wskbd_backlight *);
+extern int (*wskbd_set_backlight)(struct wskbd_backlight *);
+
+void   wsdisplay_burn_kbd(struct wsdisplay_softc *, int);
+
 struct wsdisplay_softc {
        struct device sc_dv;
 
@@ -177,6 +182,7 @@ struct wsdisplay_softc {
        int     sc_burnout;             /* current sc_burner delay (ms) */
        int     sc_burnman;             /* nonzero if screen blanked */
        int     sc_burnflags;
+       struct wskbd_backlight  sc_kbdbl_saved;
 #endif
 
        int     sc_isconsole;
@@ -1224,6 +1230,7 @@ wsdisplay_internal_ioctl(struct wsdisplay_softc *sc, s
                        return (EOPNOTSUPP);
                (*sc->sc_accessops->burn_screen)(sc->sc_accesscookie,
                     *(u_int *)data, sc->sc_burnflags);
+               wsdisplay_burn_kbd(sc, *(u_int *)data == WSDISPLAYIO_VIDEO_ON);
                sc->sc_burnman = *(u_int *)data == WSDISPLAYIO_VIDEO_OFF;
                break;
 
@@ -2409,6 +2416,7 @@ wsdisplay_burner(void *v)
        if (sc->sc_accessops->burn_screen) {
                (*sc->sc_accessops->burn_screen)(sc->sc_accesscookie,
                    sc->sc_burnman, sc->sc_burnflags);
+               wsdisplay_burn_kbd(sc, sc->sc_burnman);
                s = spltty();
                if (sc->sc_burnman) {
                        sc->sc_burnout = sc->sc_burnoutintvl;
@@ -2533,6 +2541,30 @@ wsdisplay_brightness_cycle(struct device *dev)
                wsdisplay_brightness_step(dev, 1);
 }
 
+#ifdef HAVE_BURNER_SUPPORT
+void
+wsdisplay_burn_kbd(struct wsdisplay_softc *sc, int on)
+{
+       struct wskbd_backlight bl;
+
+       if (wskbd_set_backlight == NULL ||
+           wskbd_get_backlight == NULL)
+               return;
+
+       if (!on) {
+               (*wskbd_get_backlight)(&sc->sc_kbdbl_saved);
+               bl = sc->sc_kbdbl_saved;
+               bl.curval = bl.min;
+       } else {
+               bl = sc->sc_kbdbl_saved;
+               if (bl.max == 0)
+                       return;
+       }
+
+       (*wskbd_set_backlight)(&bl);
+}
+#endif
+
 #ifdef HAVE_WSMOUSED_SUPPORT
 /*
  * wsmoused(8) support functions