Add a very simple dpms(4) driver that uses the VESA BIOS DPMS calls to

turn off the external display during suspend and restore it to its
original state on resume.

MFC after:	2 weeks

1 files changed, 230 insertions, 0 deletions

diff --git a/sys/i386/isa/dpms.c b/sys/i386/isa/dpms.c
new file mode 100644
index 0000000..723a6c0
--- /dev/null
+++ b/sys/i386/isa/dpms.c
@@ -0,0 +1,230 @@
+/*-
+ * Copyright (c) 2008 Yahoo!, Inc.
+ * All rights reserved.
+ * Written by: John Baldwin <jhb@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Copyright (c) 2004 Benjamin Close <Benjamin.Close@clearchain.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Support for managing the display via DPMS for suspend/resume.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/bus.h>
+#include <sys/kernel.h>
+#include <sys/libkern.h>
+#include <sys/module.h>
+
+#include <machine/vm86.h>
+
+/*
+ * VESA DPMS States 
+ */
+#define DPMS_ON		0x00
+#define DPMS_STANDBY	0x01
+#define DPMS_SUSPEND	0x02
+#define DPMS_OFF	0x04
+#define DPMS_REDUCEDON	0x08
+
+#define	VBE_DPMS_FUNCTION	0x4F10
+#define	VBE_DPMS_GET_SUPPORTED_STATES 0x00
+#define	VBE_DPMS_GET_STATE	0x02
+#define	VBE_DPMS_SET_STATE	0x01
+#define VBE_MAJORVERSION_MASK	0x0F
+#define VBE_MINORVERSION_MASK	0xF0
+
+struct dpms_softc {
+	int	dpms_supported_states;
+	int	dpms_initial_state;
+};
+
+static int	dpms_attach(device_t);
+static int	dpms_detach(device_t);
+static int	dpms_get_supported_states(int *);
+static int	dpms_get_current_state(int *);
+static void	dpms_identify(driver_t *, device_t);
+static int	dpms_probe(device_t);
+static int	dpms_resume(device_t);
+static int	dpms_set_state(int);
+static int	dpms_suspend(device_t);
+
+static device_method_t dpms_methods[] = {
+	DEVMETHOD(device_identify,	dpms_identify),
+	DEVMETHOD(device_probe,		dpms_probe),
+	DEVMETHOD(device_attach,	dpms_attach),
+	DEVMETHOD(device_detach,	dpms_detach),
+	DEVMETHOD(device_suspend,	dpms_suspend),
+	DEVMETHOD(device_resume,	dpms_resume),
+	{ 0, 0 }
+};
+
+static driver_t dpms_driver = {
+	"dpms",
+	dpms_methods,
+	sizeof(struct dpms_softc),
+};
+
+static devclass_t dpms_devclass;
+
+DRIVER_MODULE(dpms, vgapci, dpms_driver, dpms_devclass, NULL, NULL);
+
+static void
+dpms_identify(driver_t *driver, device_t parent)
+{
+
+	/*
+	 * XXX: The DPMS VBE only allows for manipulating a single
+	 * monitor, but we don't know which one.  Just attach to the
+	 * first vgapci(4) device we encounter and hope it is the
+	 * right one.
+	 */
+	if (devclass_get_device(dpms_devclass, 0) == NULL)
+		device_add_child(parent, "dpms", 0);
+}
+
+static int
+dpms_probe(device_t dev)
+{
+	int error, states;
+
+	error = dpms_get_supported_states(&states);
+	if (error)
+		return (error);
+	device_set_desc(dev, "DPMS suspend/resume");
+	device_quiet(dev);
+	return (BUS_PROBE_DEFAULT);
+}
+
+static int
+dpms_attach(device_t dev)
+{
+	struct dpms_softc *sc;
+	int error;
+
+	sc = device_get_softc(dev);
+	error = dpms_get_supported_states(&sc->dpms_supported_states);
+	if (error)
+		return (error);
+	error = dpms_get_current_state(&sc->dpms_initial_state);
+	return (error);
+}
+
+static int
+dpms_detach(device_t dev)
+{
+
+	return (0);
+}
+
+static int
+dpms_suspend(device_t dev)
+{
+
+	dpms_set_state(DPMS_OFF);
+	return (0);
+}
+
+static int
+dpms_resume(device_t dev)
+{
+	struct dpms_softc *sc;
+
+	sc = device_get_softc(dev);
+	dpms_set_state(sc->dpms_initial_state);
+	return (0);
+}
+
+static int
+dpms_call_bios(int subfunction, int *bh)
+{
+	struct vm86frame vmf;
+	int error;
+
+	bzero(&vmf, sizeof(vmf));
+	vmf.vmf_ax = VBE_DPMS_FUNCTION;
+	vmf.vmf_bl = subfunction;
+	vmf.vmf_bh = *bh;
+	vmf.vmf_es = 0;
+	vmf.vmf_di = 0;
+	error = vm86_intcall(0x10, &vmf);
+	if (error == 0 && (vmf.vmf_eax & 0xffff) != 0x004f)
+		error = ENXIO;
+	if (error == 0)
+		*bh = vmf.vmf_bh;
+	return (error);
+}
+
+static int
+dpms_get_supported_states(int *states)
+{
+
+	*states = 0;
+	return (dpms_call_bios(VBE_DPMS_GET_SUPPORTED_STATES, states));
+}
+
+static int
+dpms_get_current_state(int *state)
+{
+
+	*state = 0;
+	return (dpms_call_bios(VBE_DPMS_GET_STATE, state));
+}
+
+static int
+dpms_set_state(int state)
+{
+
+	return (dpms_call_bios(VBE_DPMS_SET_STATE, &state));
+}