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/param.h>
30 #include <sys/bus.h>
31 #include <sys/systm.h>
32 #include <sys/module.h>
33 #include <sys/kernel.h>
34 #include <sys/rman.h>
35 #include <sys/sysctl.h>
36
37 #include <machine/bus.h>
38
39 #include <dev/ofw/openfirm.h>
40 #include <dev/pci/pcivar.h>
41
42 #define PCI_VENDOR_ID_NVIDIA 0x10de
43
44 #define NVIDIA_BRIGHT_MIN (0x0ec)
45 #define NVIDIA_BRIGHT_MAX (0x538)
46 #define NVIDIA_BRIGHT_SCALE ((NVIDIA_BRIGHT_MAX - NVIDIA_BRIGHT_MIN)/100)
47 /* nVidia's MMIO registers are at PCI BAR[0] */
48 #define NVIDIA_MMIO_PMC (0x0)
49 #define NVIDIA_PMC_OFF (NVIDIA_MMIO_PMC + 0x10f0)
50 #define NVIDIA_PMC_BL_SHIFT (16)
51 #define NVIDIA_PMC_BL_EN (1U << 31)
52
53 struct nvbl_softc {
54 device_t dev;
55 struct resource *sc_memr;
56 };
57
58 static void nvbl_identify(driver_t *driver, device_t parent);
59 static int nvbl_probe(device_t dev);
60 static int nvbl_attach(device_t dev);
61 static int nvbl_setlevel(struct nvbl_softc *sc, int newlevel);
62 static int nvbl_getlevel(struct nvbl_softc *sc);
63 static int nvbl_sysctl(SYSCTL_HANDLER_ARGS);
64
65 static device_method_t nvbl_methods[] = {
66 /* Device interface */
67 DEVMETHOD(device_identify, nvbl_identify),
68 DEVMETHOD(device_probe, nvbl_probe),
69 DEVMETHOD(device_attach, nvbl_attach),
70 {0, 0},
71 };
72
73 static driver_t nvbl_driver = {
74 "backlight",
75 nvbl_methods,
76 sizeof(struct nvbl_softc)
77 };
78
79 DRIVER_MODULE(nvbl, vgapci, nvbl_driver, 0, 0);
80
81 static void
nvbl_identify(driver_t * driver,device_t parent)82 nvbl_identify(driver_t *driver, device_t parent)
83 {
84 if (OF_finddevice("mac-io/backlight") == -1)
85 return;
86 if (device_find_child(parent, "backlight", -1) == NULL)
87 device_add_child(parent, "backlight", -1);
88 }
89
90 static int
nvbl_probe(device_t dev)91 nvbl_probe(device_t dev)
92 {
93 char control[8];
94 phandle_t handle;
95
96 handle = OF_finddevice("mac-io/backlight");
97
98 if (handle == -1)
99 return (ENXIO);
100
101 if (OF_getprop(handle, "backlight-control", &control, sizeof(control)) < 0)
102 return (ENXIO);
103
104 if ((strcmp(control, "mnca") != 0) ||
105 pci_get_vendor(device_get_parent(dev)) != PCI_VENDOR_ID_NVIDIA)
106 return (ENXIO);
107
108 device_set_desc(dev, "PowerBook backlight for nVidia graphics");
109
110 return (0);
111 }
112
113 static int
nvbl_attach(device_t dev)114 nvbl_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 | CTLFLAG_NEEDGIANT, sc, 0,
142 nvbl_sysctl, "I", "Backlight level (0-100)");
143
144 return (0);
145 }
146
147 static int
nvbl_setlevel(struct nvbl_softc * sc,int newlevel)148 nvbl_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
168 static int
nvbl_getlevel(struct nvbl_softc * sc)169 nvbl_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
183 static int
nvbl_sysctl(SYSCTL_HANDLER_ARGS)184 nvbl_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