nvbl.c revision 331722 
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/11/sys/powerpc/powermac/nvbl.c 331722 2018-03-29 02:50:57Z 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#include <dev/pci/pcivar.h>
42
43#define PCI_VENDOR_ID_NVIDIA	0x10de
44
45#define NVIDIA_BRIGHT_MIN     (0x0ec)
46#define NVIDIA_BRIGHT_MAX     (0x538)
47#define NVIDIA_BRIGHT_SCALE   ((NVIDIA_BRIGHT_MAX - NVIDIA_BRIGHT_MIN)/100)
48/* nVidia's MMIO registers are at PCI BAR[0] */
49#define NVIDIA_MMIO_PMC       (0x0)
50#define  NVIDIA_PMC_OFF         (NVIDIA_MMIO_PMC + 0x10f0)
51#define   NVIDIA_PMC_BL_SHIFT    (16)
52#define   NVIDIA_PMC_BL_EN       (1U << 31)
53
54
55struct nvbl_softc {
56	device_t	 dev;
57	struct resource *sc_memr;
58};
59
60static void nvbl_identify(driver_t *driver, device_t parent);
61static int nvbl_probe(device_t dev);
62static int nvbl_attach(device_t dev);
63static int nvbl_setlevel(struct nvbl_softc *sc, int newlevel);
64static int nvbl_getlevel(struct nvbl_softc *sc);
65static int nvbl_sysctl(SYSCTL_HANDLER_ARGS);
66
67static device_method_t nvbl_methods[] = {
68	/* Device interface */
69	DEVMETHOD(device_identify, nvbl_identify),
70	DEVMETHOD(device_probe, nvbl_probe),
71	DEVMETHOD(device_attach, nvbl_attach),
72	{0, 0},
73};
74
75static driver_t	nvbl_driver = {
76	"backlight",
77	nvbl_methods,
78	sizeof(struct nvbl_softc)
79};
80
81static devclass_t nvbl_devclass;
82
83DRIVER_MODULE(nvbl, vgapci, nvbl_driver, nvbl_devclass, 0, 0);
84
85static void
86nvbl_identify(driver_t *driver, device_t parent)
87{
88	if (OF_finddevice("mac-io/backlight") == -1)
89		return;
90	if (device_find_child(parent, "backlight", -1) == NULL)
91		device_add_child(parent, "backlight", -1);
92}
93
94static int
95nvbl_probe(device_t dev)
96{
97	char		control[8];
98	phandle_t	handle;
99
100	handle = OF_finddevice("mac-io/backlight");
101
102	if (handle == -1)
103		return (ENXIO);
104
105	if (OF_getprop(handle, "backlight-control", &control, sizeof(control)) < 0)
106		return (ENXIO);
107
108	if ((strcmp(control, "mnca") != 0) ||
109	    pci_get_vendor(device_get_parent(dev)) != PCI_VENDOR_ID_NVIDIA)
110		return (ENXIO);
111
112	device_set_desc(dev, "PowerBook backlight for nVidia graphics");
113
114	return (0);
115}
116
117static int
118nvbl_attach(device_t dev)
119{
120	struct nvbl_softc	*sc;
121	struct sysctl_ctx_list *ctx;
122	struct sysctl_oid *tree;
123	int			 rid;
124
125	sc = device_get_softc(dev);
126
127	rid = 0x10;	/* BAR[0], for the MMIO register */
128	sc->sc_memr = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
129			RF_ACTIVE | RF_SHAREABLE);
130	if (sc->sc_memr == NULL) {
131		device_printf(dev, "Could not alloc mem resource!\n");
132		return (ENXIO);
133	}
134
135	/* Turn on big-endian mode */
136	if (!(bus_read_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4) & 0x01000001)) {
137		bus_write_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4, 0x01000001);
138		mb();
139	}
140
141	ctx = device_get_sysctl_ctx(dev);
142	tree = device_get_sysctl_tree(dev);
143
144	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
145			"level", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
146			nvbl_sysctl, "I", "Backlight level (0-100)");
147
148	return (0);
149}
150
151static int
152nvbl_setlevel(struct nvbl_softc *sc, int newlevel)
153{
154	uint32_t pmc_reg;
155
156	if (newlevel > 100)
157		newlevel = 100;
158
159	if (newlevel < 0)
160		newlevel = 0;
161
162	if (newlevel > 0)
163		newlevel = (newlevel * NVIDIA_BRIGHT_SCALE) + NVIDIA_BRIGHT_MIN;
164
165	pmc_reg = bus_read_stream_4(sc->sc_memr, NVIDIA_PMC_OFF) & 0xffff;
166	pmc_reg |= NVIDIA_PMC_BL_EN | (newlevel << NVIDIA_PMC_BL_SHIFT);
167	bus_write_stream_4(sc->sc_memr, NVIDIA_PMC_OFF, pmc_reg);
168
169	return (0);
170}
171
172static int
173nvbl_getlevel(struct nvbl_softc *sc)
174{
175	uint16_t level;
176
177	level = bus_read_stream_2(sc->sc_memr, NVIDIA_PMC_OFF) & 0x7fff;
178
179	if (level  < NVIDIA_BRIGHT_MIN)
180		return 0;
181
182	level = (level - NVIDIA_BRIGHT_MIN) / NVIDIA_BRIGHT_SCALE;
183
184	return (level);
185}
186
187static int
188nvbl_sysctl(SYSCTL_HANDLER_ARGS)
189{
190	struct nvbl_softc *sc;
191	int newlevel, error;
192
193	sc = arg1;
194
195	newlevel = nvbl_getlevel(sc);
196
197	error = sysctl_handle_int(oidp, &newlevel, 0, req);
198
199	if (error || !req->newptr)
200		return (error);
201
202	return (nvbl_setlevel(sc, newlevel));
203}
204