1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2012 Justin Hibbits
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
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 struct nvbl_softc {
55 device_t dev;
56 struct resource *sc_memr;
57 };
58
59 static void nvbl_identify(driver_t *driver, device_t parent);
60 static int nvbl_probe(device_t dev);
61 static int nvbl_attach(device_t dev);
62 static int nvbl_setlevel(struct nvbl_softc *sc, int newlevel);
63 static int nvbl_getlevel(struct nvbl_softc *sc);
64 static int nvbl_sysctl(SYSCTL_HANDLER_ARGS);
65
66 static device_method_t nvbl_methods[] = {
67 /* Device interface */
68 DEVMETHOD(device_identify, nvbl_identify),
69 DEVMETHOD(device_probe, nvbl_probe),
70 DEVMETHOD(device_attach, nvbl_attach),
71 {0, 0},
72 };
73
74 static driver_t nvbl_driver = {
75 "backlight",
76 nvbl_methods,
77 sizeof(struct nvbl_softc)
78 };
79
80 DRIVER_MODULE(nvbl, vgapci, nvbl_driver, 0, 0);
81
82 static void
nvbl_identify(driver_t * driver,device_t parent)83 nvbl_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
91 static int
nvbl_probe(device_t dev)92 nvbl_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 pci_get_vendor(device_get_parent(dev)) != PCI_VENDOR_ID_NVIDIA)
107 return (ENXIO);
108
109 device_set_desc(dev, "PowerBook backlight for nVidia graphics");
110
111 return (0);
112 }
113
114 static int
nvbl_attach(device_t dev)115 nvbl_attach(device_t dev)
116 {
117 struct nvbl_softc *sc;
118 struct sysctl_ctx_list *ctx;
119 struct sysctl_oid *tree;
120 int rid;
121
122 sc = device_get_softc(dev);
123
124 rid = 0x10; /* BAR[0], for the MMIO register */
125 sc->sc_memr = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
126 RF_ACTIVE | RF_SHAREABLE);
127 if (sc->sc_memr == NULL) {
128 device_printf(dev, "Could not alloc mem resource!\n");
129 return (ENXIO);
130 }
131
132 /* Turn on big-endian mode */
133 if (!(bus_read_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4) & 0x01000001)) {
134 bus_write_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4, 0x01000001);
135 mb();
136 }
137
138 ctx = device_get_sysctl_ctx(dev);
139 tree = device_get_sysctl_tree(dev);
140
141 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
142 "level", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc, 0,
143 nvbl_sysctl, "I", "Backlight level (0-100)");
144
145 return (0);
146 }
147
148 static int
nvbl_setlevel(struct nvbl_softc * sc,int newlevel)149 nvbl_setlevel(struct nvbl_softc *sc, int newlevel)
150 {
151 uint32_t pmc_reg;
152
153 if (newlevel > 100)
154 newlevel = 100;
155
156 if (newlevel < 0)
157 newlevel = 0;
158
159 if (newlevel > 0)
160 newlevel = (newlevel * NVIDIA_BRIGHT_SCALE) + NVIDIA_BRIGHT_MIN;
161
162 pmc_reg = bus_read_stream_4(sc->sc_memr, NVIDIA_PMC_OFF) & 0xffff;
163 pmc_reg |= NVIDIA_PMC_BL_EN | (newlevel << NVIDIA_PMC_BL_SHIFT);
164 bus_write_stream_4(sc->sc_memr, NVIDIA_PMC_OFF, pmc_reg);
165
166 return (0);
167 }
168
169 static int
nvbl_getlevel(struct nvbl_softc * sc)170 nvbl_getlevel(struct nvbl_softc *sc)
171 {
172 uint16_t level;
173
174 level = bus_read_stream_2(sc->sc_memr, NVIDIA_PMC_OFF) & 0x7fff;
175
176 if (level < NVIDIA_BRIGHT_MIN)
177 return 0;
178
179 level = (level - NVIDIA_BRIGHT_MIN) / NVIDIA_BRIGHT_SCALE;
180
181 return (level);
182 }
183
184 static int
nvbl_sysctl(SYSCTL_HANDLER_ARGS)185 nvbl_sysctl(SYSCTL_HANDLER_ARGS)
186 {
187 struct nvbl_softc *sc;
188 int newlevel, error;
189
190 sc = arg1;
191
192 newlevel = nvbl_getlevel(sc);
193
194 error = sysctl_handle_int(oidp, &newlevel, 0, req);
195
196 if (error || !req->newptr)
197 return (error);
198
199 return (nvbl_setlevel(sc, newlevel));
200 }
201