Add backlight support for nVidia-based PowerBooks/iBooks/iMacs.

Approved by:	nwhitehorn (mentor)
MFC after:	9.1-RELEASE

1 files changed, 197 insertions, 0 deletions

diff --git a/sys/powerpc/powermac/nvbl.c b/sys/powerpc/powermac/nvbl.c
new file mode 100644
index 0000000..3317075
--- /dev/null
+++ b/sys/powerpc/powermac/nvbl.c
@@ -0,0 +1,197 @@
+/*-
+ * Copyright (c) 2012 Justin Hibbits
+ * 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 ``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 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/bus.h>
+#include <sys/systm.h>
+#include <sys/module.h>
+#include <sys/kernel.h>
+#include <sys/rman.h>
+#include <sys/sysctl.h>
+
+#include <machine/bus.h>
+
+#include <dev/ofw/openfirm.h>
+
+#define NVIDIA_BRIGHT_MIN     (0x0ec)
+#define NVIDIA_BRIGHT_MAX     (0x538)
+#define NVIDIA_BRIGHT_SCALE   ((NVIDIA_BRIGHT_MAX - NVIDIA_BRIGHT_MIN)/100)
+/* nVidia's MMIO registers are at PCI BAR[0] */
+#define NVIDIA_MMIO_PMC       (0x0)
+#define  NVIDIA_PMC_OFF         (NVIDIA_MMIO_PMC + 0x10f0)
+#define   NVIDIA_PMC_BL_SHIFT    (16)
+#define   NVIDIA_PMC_BL_EN       (1 << 31)
+
+
+struct nvbl_softc {
+	device_t	 dev;
+	struct resource *sc_memr;
+};
+
+static void nvbl_identify(driver_t *driver, device_t parent);
+static int nvbl_probe(device_t dev);
+static int nvbl_attach(device_t dev);
+static int nvbl_setlevel(struct nvbl_softc *sc, int newlevel);
+static int nvbl_getlevel(struct nvbl_softc *sc);
+static int nvbl_sysctl(SYSCTL_HANDLER_ARGS);
+
+static device_method_t nvbl_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_identify, nvbl_identify),
+	DEVMETHOD(device_probe, nvbl_probe),
+	DEVMETHOD(device_attach, nvbl_attach),
+	{0, 0},
+};
+
+static driver_t	nvbl_driver = {
+	"backlight",
+	nvbl_methods,
+	sizeof(struct nvbl_softc)
+};
+
+static devclass_t nvbl_devclass;
+
+DRIVER_MODULE(nvbl, vgapci, nvbl_driver, nvbl_devclass, 0, 0);
+
+static void
+nvbl_identify(driver_t *driver, device_t parent)
+{
+	if (device_find_child(parent, "backlight", -1) == NULL)
+		device_add_child(parent, "backlight", -1);
+}
+
+static int
+nvbl_probe(device_t dev)
+{
+	char		control[8];
+	phandle_t	handle;
+
+	handle = OF_finddevice("mac-io/backlight");
+
+	if (handle <= 0)
+		return (ENXIO);
+
+	if (OF_getprop(handle, "backlight-control", &control, sizeof(control)) < 0)
+		return (ENXIO);
+
+	if (strcmp(control, "mnca") != 0)
+		return (ENXIO);
+
+	device_set_desc(dev, "PowerBook backlight for nVidia graphics");
+
+	return (0);
+}
+
+static int
+nvbl_attach(device_t dev)
+{
+	struct nvbl_softc	*sc;
+	struct sysctl_ctx_list *ctx;
+	struct sysctl_oid *tree;
+	int			 rid;
+
+	sc = device_get_softc(dev);
+
+	rid = 0x10;	/* BAR[0], for the MMIO register */
+	sc->sc_memr = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
+			RF_ACTIVE | RF_SHAREABLE);
+	if (sc->sc_memr == NULL) {
+		device_printf(dev, "Could not alloc mem resource!\n");
+		return (ENXIO);
+	}
+
+	/* Turn on big-endian mode */
+	if (!(bus_read_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4) & 0x01000001)) {
+		bus_write_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4, 0x01000001);
+		mb();
+	}
+
+	ctx = device_get_sysctl_ctx(dev);
+	tree = device_get_sysctl_tree(dev);
+
+	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
+			"level", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
+			nvbl_sysctl, "I", "Backlight level (0-100)");
+
+	return (0);
+}
+
+static int
+nvbl_setlevel(struct nvbl_softc *sc, int newlevel)
+{
+	uint32_t pmc_reg;
+
+	if (newlevel > 100)
+		newlevel = 100;
+
+	if (newlevel < 0)
+		newlevel = 0;
+
+	if (newlevel > 0)
+		newlevel = (newlevel * NVIDIA_BRIGHT_SCALE) + NVIDIA_BRIGHT_MIN;
+
+	pmc_reg = bus_read_stream_4(sc->sc_memr, NVIDIA_PMC_OFF) & 0xffff;
+	pmc_reg |= NVIDIA_PMC_BL_EN | (newlevel << NVIDIA_PMC_BL_SHIFT);
+	bus_write_stream_4(sc->sc_memr, NVIDIA_PMC_OFF, pmc_reg);
+
+	return (0);
+}
+
+static int
+nvbl_getlevel(struct nvbl_softc *sc)
+{
+	uint16_t level;
+
+	level = bus_read_stream_2(sc->sc_memr, NVIDIA_PMC_OFF) & 0x7fff;
+
+	if (level  < NVIDIA_BRIGHT_MIN)
+		return 0;
+
+	level = (level - NVIDIA_BRIGHT_MIN) / NVIDIA_BRIGHT_SCALE;
+
+	return (level);
+}
+
+static int
+nvbl_sysctl(SYSCTL_HANDLER_ARGS)
+{
+	struct nvbl_softc *sc;
+	int newlevel, error;
+
+	sc = arg1;
+
+	newlevel = nvbl_getlevel(sc);
+
+	error = sysctl_handle_int(oidp, &newlevel, 0, req);
+
+	if (error || !req->newptr)
+		return (error);
+
+	return (nvbl_setlevel(sc, newlevel));
+}