Add display brightness support. This is available on the last few generations

of Thinkpads (x220 and later) and using means the brightness level is
coordinated properly with the firmware.  This gets rid of the surprising
brightness changes that would sometimes happen if you used the brightness
keys or if the firmware decided to reset the brightness level for some
other reason.

ok tedu@, jung@, naddy@

1 files changed, 83 insertions, 3 deletions

diff --git a/sys/dev/acpi/acpithinkpad.c b/sys/dev/acpi/acpithinkpad.c
index ebc4f3e48f2..740c47cc2ee 100644
--- a/sys/dev/acpi/acpithinkpad.c
+++ b/sys/dev/acpi/acpithinkpad.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: acpithinkpad.c,v 1.49 2015/12/16 15:43:14 kettenis Exp $	*/
+/*	$OpenBSD: acpithinkpad.c,v 1.50 2015/12/17 12:17:14 kettenis Exp $	*/
 /*
  * Copyright (c) 2008 joshua stein <jcs@openbsd.org>
  *
@@ -122,6 +122,8 @@ struct acpithinkpad_softc {
 	uint64_t		 sc_thinklight;
 	const char		*sc_thinklight_get;
 	const char		*sc_thinklight_set;
+
+	uint64_t		 sc_brightness;
 };
 
 extern void acpiec_read(struct acpiec_softc *, u_int8_t, int, u_int8_t *);
@@ -141,13 +143,19 @@ int	thinkpad_brightness_down(struct acpithinkpad_softc *);
 int	thinkpad_adaptive_change(struct acpithinkpad_softc *);
 int	thinkpad_activate(struct device *, int);
 
-/* wskbd hook functions */
+/* wscons hook functions */
 void	thinkpad_get_thinklight(struct acpithinkpad_softc *);
 void	thinkpad_set_thinklight(void *, int);
 int	thinkpad_get_backlight(struct wskbd_backlight *);
 int	thinkpad_set_backlight(struct wskbd_backlight *);
 extern int (*wskbd_get_backlight)(struct wskbd_backlight *);
 extern int (*wskbd_set_backlight)(struct wskbd_backlight *);
+void	thinkpad_get_brightness(struct acpithinkpad_softc *);
+void	thinkpad_set_brightness(void *, int);
+int	thinkpad_get_param(struct wsdisplay_param *);
+int	thinkpad_set_param(struct wsdisplay_param *);
+extern int (*ws_get_param)(struct wsdisplay_param *);
+extern int (*ws_set_param)(struct wsdisplay_param *);
 
 void    thinkpad_sensor_attach(struct acpithinkpad_softc *sc);
 void    thinkpad_sensor_refresh(void *);
@@ -267,6 +275,12 @@ thinkpad_attach(struct device *parent, struct device *self, void *aux)
 		wskbd_set_backlight = thinkpad_set_backlight;
 	}
 
+	if (aml_evalinteger(sc->sc_acpi, sc->sc_devnode, "PBLG",
+	    0, NULL, &sc->sc_brightness) == 0) {
+		ws_get_param = thinkpad_get_param;
+		ws_set_param = thinkpad_set_param;
+	}
+
 	/* Run thinkpad_hotkey on button presses */
 	aml_register_notify(sc->sc_devnode, aa->aaa_dev,
 	    thinkpad_hotkey, sc, ACPIDEV_POLL);
@@ -391,6 +405,9 @@ thinkpad_hotkey(struct aml_node *node, int notify_type, void *arg)
 			thinkpad_adaptive_change(sc);
 			handled = 1;
 			break;
+		case THINKPAD_BACKLIGHT_CHANGED:
+			thinkpad_get_brightness(sc);
+			break;
 		case THINKPAD_ADAPTIVE_BACK:
 		case THINKPAD_ADAPTIVE_GESTURES:
 		case THINKPAD_ADAPTIVE_REFRESH:
@@ -398,7 +415,6 @@ thinkpad_hotkey(struct aml_node *node, int notify_type, void *arg)
 		case THINKPAD_ADAPTIVE_SNIP:
 		case THINKPAD_ADAPTIVE_TAB:
 		case THINKPAD_ADAPTIVE_VOICE:
-		case THINKPAD_BACKLIGHT_CHANGED:
 		case THINKPAD_KEYLIGHT_CHANGED:
 		case THINKPAD_BRIGHTNESS_CHANGED:
 		case THINKPAD_BUTTON_BATTERY_INFO:
@@ -631,3 +647,67 @@ thinkpad_set_backlight(struct wskbd_backlight *kbl)
 	acpi_wakeup(sc->sc_acpi);
 	return 0;
 }
+
+void
+thinkpad_get_brightness(struct acpithinkpad_softc *sc)
+{
+	aml_evalinteger(sc->sc_acpi, sc->sc_devnode,
+	    "PBLG", 0, NULL, &sc->sc_brightness);
+}
+
+void
+thinkpad_set_brightness(void *arg0, int arg1)
+{
+	struct acpithinkpad_softc *sc = arg0;
+	struct aml_value arg;
+
+	memset(&arg, 0, sizeof(arg));
+	arg.type = AML_OBJTYPE_INTEGER;
+	arg.v_integer = sc->sc_brightness & 0xff;
+	aml_evalname(sc->sc_acpi, sc->sc_devnode,
+	    "PBLS", 1, &arg, NULL);
+}
+
+int
+thinkpad_get_param(struct wsdisplay_param *dp)
+{
+	struct acpithinkpad_softc *sc = acpithinkpad_cd.cd_devs[0];
+
+	if (sc == NULL)
+		return -1;
+
+	switch (dp->param) {
+	case WSDISPLAYIO_PARAM_BRIGHTNESS:
+		dp->min = 0;
+		dp->max = (sc->sc_brightness >> 8) & 0xff;
+		dp->curval = sc->sc_brightness & 0xff;
+		return 0;
+	default:
+		return -1;
+	}
+}
+
+int
+thinkpad_set_param(struct wsdisplay_param *dp)
+{
+	struct acpithinkpad_softc *sc = acpithinkpad_cd.cd_devs[0];
+	int maxval = (sc->sc_brightness >> 8) & 0xff;
+
+	if (sc == NULL)
+		return -1;
+
+	switch (dp->param) {
+	case WSDISPLAYIO_PARAM_BRIGHTNESS:
+		if (dp->curval < 0)
+			dp->curval = 0;
+		if (dp->curval > maxval)
+			dp->curval = maxval;
+		sc->sc_brightness &= ~0xff;
+		sc->sc_brightness |= dp->curval;
+		acpi_addtask(sc->sc_acpi, thinkpad_set_brightness, sc, 0);
+		acpi_wakeup(sc->sc_acpi);
+		return 0;
+	default:
+		return -1;
+	}
+}