Add backlight control to ATI-graphics PowerBooks and iBooks.

Approved by:	nwhitehorn (mentor)
MFC after:	1 week

1 files changed, 196 insertions, 0 deletions

diff --git a/sys/powerpc/powermac/atibl.c b/sys/powerpc/powermac/atibl.c
new file mode 100644
index 0000000..ff26dfe
--- /dev/null
+++ b/sys/powerpc/powermac/atibl.c
@@ -0,0 +1,196 @@
+/*-
+ * 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>
+
+/* From the xf86-video-ati driver's radeon_reg.h */
+#define RADEON_LVDS_GEN_CNTL         0x02d0
+#define  RADEON_LVDS_ON               (1   <<  0)
+#define  RADEON_LVDS_DISPLAY_DIS      (1   <<  1)
+#define  RADEON_LVDS_PANEL_TYPE       (1   <<  2)
+#define  RADEON_LVDS_PANEL_FORMAT     (1   <<  3)
+#define  RADEON_LVDS_RST_FM           (1   <<  6)
+#define  RADEON_LVDS_EN               (1   <<  7)
+#define  RADEON_LVDS_BL_MOD_LEVEL_SHIFT 8
+#define  RADEON_LVDS_BL_MOD_LEVEL_MASK (0xff << 8)
+#define  RADEON_LVDS_BL_MOD_EN        (1   << 16)
+#define  RADEON_LVDS_DIGON            (1   << 18)
+#define  RADEON_LVDS_BLON             (1   << 19)
+
+struct atibl_softc {
+	device_t	 dev;
+	struct resource *sc_memr;
+};
+
+static void atibl_identify(driver_t *driver, device_t parent);
+static int atibl_probe(device_t dev);
+static int atibl_attach(device_t dev);
+static int atibl_setlevel(struct atibl_softc *sc, int newlevel);
+static int atibl_getlevel(struct atibl_softc *sc);
+static int atibl_sysctl(SYSCTL_HANDLER_ARGS);
+
+static device_method_t atibl_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_identify, atibl_identify),
+	DEVMETHOD(device_probe, atibl_probe),
+	DEVMETHOD(device_attach, atibl_attach),
+	{0, 0},
+};
+
+static driver_t	atibl_driver = {
+	"backlight",
+	atibl_methods,
+	sizeof(struct atibl_softc)
+};
+
+static devclass_t atibl_devclass;
+
+DRIVER_MODULE(atibl, vgapci, atibl_driver, atibl_devclass, 0, 0);
+
+static void
+atibl_identify(driver_t *driver, device_t parent)
+{
+	if (device_find_child(parent, "backlight", -1) == NULL)
+		device_add_child(parent, "backlight", -1);
+}
+
+static int
+atibl_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, "ati") != 0)
+		return (ENXIO);
+
+	device_set_desc(dev, "PowerBook backlight");
+
+	return (0);
+}
+
+static int
+atibl_attach(device_t dev)
+{
+	struct atibl_softc	*sc;
+	struct sysctl_ctx_list *ctx;
+	struct sysctl_oid *tree;
+	int			 rid;
+
+	sc = device_get_softc(dev);
+
+	rid = 0x18;	/* BAR[2], 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);
+	}
+
+	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,
+			atibl_sysctl, "I", "Backlight level (0-100)");
+
+	return (0);
+}
+
+static int
+atibl_setlevel(struct atibl_softc *sc, int newlevel)
+{
+	uint32_t lvds_gen_cntl;
+
+	if (newlevel > 100)
+		newlevel = 100;
+
+	if (newlevel < 0)
+		newlevel = 0;
+
+	newlevel = (newlevel * 5) / 2 + 5;
+	lvds_gen_cntl = bus_read_4(sc->sc_memr, RADEON_LVDS_GEN_CNTL);
+	lvds_gen_cntl |= RADEON_LVDS_BL_MOD_EN;
+	lvds_gen_cntl &= ~RADEON_LVDS_BL_MOD_LEVEL_MASK;
+	lvds_gen_cntl |= (newlevel << RADEON_LVDS_BL_MOD_LEVEL_SHIFT) &
+		RADEON_LVDS_BL_MOD_LEVEL_MASK;
+	bus_write_4(sc->sc_memr, RADEON_LVDS_GEN_CNTL, lvds_gen_cntl);
+
+	return (0);
+}
+
+static int
+atibl_getlevel(struct atibl_softc *sc)
+{
+	uint32_t	lvds_gen_cntl;
+	int			level;
+
+	lvds_gen_cntl = bus_read_4(sc->sc_memr, RADEON_LVDS_GEN_CNTL);
+
+	level = ((lvds_gen_cntl & RADEON_LVDS_BL_MOD_LEVEL_MASK) >>
+			RADEON_LVDS_BL_MOD_LEVEL_SHIFT);
+	level = ((level - 5) * 2) / 5;
+
+	return (level);
+}
+
+static int
+atibl_sysctl(SYSCTL_HANDLER_ARGS)
+{
+	struct atibl_softc *sc;
+	int newlevel, error;
+
+	sc = arg1;
+
+	newlevel = atibl_getlevel(sc);
+
+	error = sysctl_handle_int(oidp, &newlevel, 0, req);
+
+	if (error || !req->newptr)
+		return (error);
+
+	return (atibl_setlevel(sc, newlevel));
+}