nvbl.c revision 261455 
1/*-
2 * Copyright (c) 2012 Justin Hibbits
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/10/sys/powerpc/powermac/nvbl.c 261455 2014-02-04 03:36:42Z eadler $");
29
30#include <sys/param.h>
31#include <sys/bus.h>
32#include <sys/systm.h>
33#include <sys/module.h>
34#include <sys/kernel.h>
35#include <sys/rman.h>
36#include <sys/sysctl.h>
37
38#include <machine/bus.h>
39
40#include <dev/ofw/openfirm.h>
41
42#define NVIDIA_BRIGHT_MIN     (0x0ec)
43#define NVIDIA_BRIGHT_MAX     (0x538)
44#define NVIDIA_BRIGHT_SCALE   ((NVIDIA_BRIGHT_MAX - NVIDIA_BRIGHT_MIN)/100)
45/* nVidia's MMIO registers are at PCI BAR[0] */
46#define NVIDIA_MMIO_PMC       (0x0)
47#define  NVIDIA_PMC_OFF         (NVIDIA_MMIO_PMC + 0x10f0)
48#define   NVIDIA_PMC_BL_SHIFT    (16)
49#define   NVIDIA_PMC_BL_EN       (1U << 31)
50
51
52struct nvbl_softc {
53	device_t	 dev;
54	struct resource *sc_memr;
55};
56
57static void nvbl_identify(driver_t *driver, device_t parent);
58static int nvbl_probe(device_t dev);
59static int nvbl_attach(device_t dev);
60static int nvbl_setlevel(struct nvbl_softc *sc, int newlevel);
61static int nvbl_getlevel(struct nvbl_softc *sc);
62static int nvbl_sysctl(SYSCTL_HANDLER_ARGS);
63
64static device_method_t nvbl_methods[] = {
65	/* Device interface */
66	DEVMETHOD(device_identify, nvbl_identify),
67	DEVMETHOD(device_probe, nvbl_probe),
68	DEVMETHOD(device_attach, nvbl_attach),
69	{0, 0},
70};
71
72static driver_t	nvbl_driver = {
73	"backlight",
74	nvbl_methods,
75	sizeof(struct nvbl_softc)
76};
77
78static devclass_t nvbl_devclass;
79
80DRIVER_MODULE(nvbl, vgapci, nvbl_driver, nvbl_devclass, 0, 0);
81
82static void
83nvbl_identify(driver_t *driver, device_t parent)
84{
85	if (OF_finddevice("mac-io/backlight") == -1)
86		return;
87	if (device_find_child(parent, "backlight", -1) == NULL)
88		device_add_child(parent, "backlight", -1);
89}
90
91static int
92nvbl_probe(device_t dev)
93{
94	char		control[8];
95	phandle_t	handle;
96
97	handle = OF_finddevice("mac-io/backlight");
98
99	if (handle == -1)
100		return (ENXIO);
101
102	if (OF_getprop(handle, "backlight-control", &control, sizeof(control)) < 0)
103		return (ENXIO);
104
105	if (strcmp(control, "mnca") != 0)
106		return (ENXIO);
107
108	device_set_desc(dev, "PowerBook backlight for nVidia graphics");
109
110	return (0);
111}
112
113static int
114nvbl_attach(device_t dev)
115{
116	struct nvbl_softc	*sc;
117	struct sysctl_ctx_list *ctx;
118	struct sysctl_oid *tree;
119	int			 rid;
120
121	sc = device_get_softc(dev);
122
123	rid = 0x10;	/* BAR[0], for the MMIO register */
124	sc->sc_memr = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
125			RF_ACTIVE | RF_SHAREABLE);
126	if (sc->sc_memr == NULL) {
127		device_printf(dev, "Could not alloc mem resource!\n");
128		return (ENXIO);
129	}
130
131	/* Turn on big-endian mode */
132	if (!(bus_read_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4) & 0x01000001)) {
133		bus_write_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4, 0x01000001);
134		mb();
135	}
136
137	ctx = device_get_sysctl_ctx(dev);
138	tree = device_get_sysctl_tree(dev);
139
140	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
141			"level", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
142			nvbl_sysctl, "I", "Backlight level (0-100)");
143
144	return (0);
145}
146
147static int
148nvbl_setlevel(struct nvbl_softc *sc, int newlevel)
149{
150	uint32_t pmc_reg;
151
152	if (newlevel > 100)
153		newlevel = 100;
154
155	if (newlevel < 0)
156		newlevel = 0;
157
158	if (newlevel > 0)
159		newlevel = (newlevel * NVIDIA_BRIGHT_SCALE) + NVIDIA_BRIGHT_MIN;
160
161	pmc_reg = bus_read_stream_4(sc->sc_memr, NVIDIA_PMC_OFF) & 0xffff;
162	pmc_reg |= NVIDIA_PMC_BL_EN | (newlevel << NVIDIA_PMC_BL_SHIFT);
163	bus_write_stream_4(sc->sc_memr, NVIDIA_PMC_OFF, pmc_reg);
164
165	return (0);
166}
167
168static int
169nvbl_getlevel(struct nvbl_softc *sc)
170{
171	uint16_t level;
172
173	level = bus_read_stream_2(sc->sc_memr, NVIDIA_PMC_OFF) & 0x7fff;
174
175	if (level  < NVIDIA_BRIGHT_MIN)
176		return 0;
177
178	level = (level - NVIDIA_BRIGHT_MIN) / NVIDIA_BRIGHT_SCALE;
179
180	return (level);
181}
182
183static int
184nvbl_sysctl(SYSCTL_HANDLER_ARGS)
185{
186	struct nvbl_softc *sc;
187	int newlevel, error;
188
189	sc = arg1;
190
191	newlevel = nvbl_getlevel(sc);
192
193	error = sysctl_handle_int(oidp, &newlevel, 0, req);
194
195	if (error || !req->newptr)
196		return (error);
197
198	return (nvbl_setlevel(sc, newlevel));
199}
200