add a simple keyboard backlight driver for some chromebooks,

adjustable with wsconsctl keyboard.backlight

ok bmercer, kettenis

3 files changed, 148 insertions, 2 deletions

diff --git a/sys/arch/amd64/conf/GENERIC b/sys/arch/amd64/conf/GENERIC
index c9d46faa1a0..7cb016a2139 100644
--- a/sys/arch/amd64/conf/GENERIC
+++ b/sys/arch/amd64/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.422 2016/06/28 04:41:37 jmatthew Exp $
+#	$OpenBSD: GENERIC,v 1.423 2016/07/01 15:02:49 jcs Exp $
 #
 # For further information on compiling OpenBSD kernels, see the config(8)
 # man page.
@@ -64,6 +64,7 @@ aibs*		at acpi?
 bytgpio*	at acpi?
 chvgpio*	at acpi?
 sdhc*		at acpi?
+acpicbkbd*	at acpi?
 
 mpbios0		at bios0
 
diff --git a/sys/dev/acpi/acpicbkbd.c b/sys/dev/acpi/acpicbkbd.c
new file mode 100644
index 00000000000..b0951a792f0
--- /dev/null
+++ b/sys/dev/acpi/acpicbkbd.c
@@ -0,0 +1,140 @@
+/* $OpenBSD: acpicbkbd.c,v 1.1 2016/07/01 15:02:49 jcs Exp $ */
+/*
+ * Copyright (c) 2016 joshua stein <jcs@openbsd.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+
+#include <dev/acpi/acpivar.h>
+#include <dev/acpi/amltypes.h>
+#include <dev/acpi/dsdt.h>
+
+#include <dev/wscons/wsconsio.h>
+
+#ifdef ACPICBKBD_DEBUG
+#define DPRINTF(x)	printf x
+#else
+#define DPRINTF(x)
+#endif
+
+#define ACPICBKBD_MAX_BACKLIGHT	100
+
+struct acpicbkbd_softc {
+	struct device		sc_dev;
+	struct acpi_softc	*sc_acpi;
+	struct aml_node		*sc_devnode;
+
+	uint64_t		sc_backlight;
+};
+
+int	acpicbkbd_match(struct device *, void *, void *);
+void	acpicbkbd_attach(struct device *, struct device *, void *);
+
+int	acpicbkbd_get_backlight(struct wskbd_backlight *);
+int	acpicbkbd_set_backlight(struct wskbd_backlight *);
+void	acpicbkbd_write_backlight(void *, int);
+extern int (*wskbd_get_backlight)(struct wskbd_backlight *);
+extern int (*wskbd_set_backlight)(struct wskbd_backlight *);
+
+struct cfattach acpicbkbd_ca = {
+	sizeof(struct acpicbkbd_softc), acpicbkbd_match, acpicbkbd_attach
+};
+
+struct cfdriver acpicbkbd_cd = {
+	NULL, "acpicbkbd", DV_DULL
+};
+
+const char *acpicbkbd_hids[] = {
+	"GOOG0002",
+	NULL
+};
+
+int
+acpicbkbd_match(struct device *parent, void *match, void *aux)
+{
+	struct acpi_attach_args *aaa = aux;
+	struct cfdata *cf = match;
+
+	return acpi_matchhids(aaa, acpicbkbd_hids, cf->cf_driver->cd_name);
+}
+
+void
+acpicbkbd_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct acpicbkbd_softc	*sc = (struct acpicbkbd_softc *)self;
+	struct acpi_attach_args *aa = aux;
+
+	sc->sc_acpi = (struct acpi_softc *)parent;
+	sc->sc_devnode = aa->aaa_node;
+
+	printf(": %s", sc->sc_devnode->name);
+
+	if (aml_evalinteger(sc->sc_acpi, sc->sc_devnode, "KBQC",
+	    0, NULL, &sc->sc_backlight) == 0) {
+		wskbd_get_backlight = acpicbkbd_get_backlight;
+		wskbd_set_backlight = acpicbkbd_set_backlight;
+	} else
+		printf(", no backlight control");
+
+	printf("\n");
+}
+
+int
+acpicbkbd_get_backlight(struct wskbd_backlight *kbl)
+{
+	struct acpicbkbd_softc *sc = acpicbkbd_cd.cd_devs[0];
+
+	KASSERT(sc != NULL);
+
+	kbl->min = 0;
+	kbl->max = ACPICBKBD_MAX_BACKLIGHT;
+	kbl->curval = sc->sc_backlight;
+
+	return 0;
+}
+
+int
+acpicbkbd_set_backlight(struct wskbd_backlight *kbl)
+{
+	struct acpicbkbd_softc *sc = acpicbkbd_cd.cd_devs[0];
+
+	KASSERT(sc != NULL);
+
+	if (kbl->curval > ACPICBKBD_MAX_BACKLIGHT)
+		return EINVAL;
+
+	sc->sc_backlight = kbl->curval;
+
+	acpi_addtask(sc->sc_acpi, acpicbkbd_write_backlight, sc, 0);
+	acpi_wakeup(sc->sc_acpi);
+
+	return 0;
+}
+
+void
+acpicbkbd_write_backlight(void *arg0, int arg1)
+{
+	struct acpicbkbd_softc *sc = arg0;
+	struct aml_value arg;
+
+	DPRINTF(("%s: writing backlight of %lld\n", DEVNAME(sc),
+	    sc->sc_backlight));
+
+	memset(&arg, 0, sizeof(arg));
+	arg.type = AML_OBJTYPE_INTEGER;
+	arg.v_integer = sc->sc_backlight;
+	aml_evalname(sc->sc_acpi, sc->sc_devnode, "KBCM", 1, &arg, NULL);
+}
diff --git a/sys/dev/acpi/files.acpi b/sys/dev/acpi/files.acpi
index 0798ca324e7..076596a3848 100644
--- a/sys/dev/acpi/files.acpi
+++ b/sys/dev/acpi/files.acpi
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.acpi,v 1.32 2016/05/07 23:10:50 kettenis Exp $
+#	$OpenBSD: files.acpi,v 1.33 2016/07/01 15:02:49 jcs Exp $
 #
 # Config file and device description for machine-independent ACPI code.
 # Included by ports that need it.
@@ -130,3 +130,8 @@ file	dev/acpi/sdhc_acpi.c		sdhc_acpi
 device	dwiic: i2cbus
 attach	dwiic at acpi
 file	dev/acpi/dwiic.c		dwiic
+
+# Chromebook keyboard backlight
+device	acpicbkbd
+attach	acpicbkbd at acpi
+file	dev/acpi/acpicbkbd.c		acpicbkbd