xref: /freebsd/sys/powerpc/powermac/nvbl.c (revision 7afb8adff33d47f10a11368ff54bb2eec5b30165)
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("$FreeBSD$");
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 
55 struct nvbl_softc {
56 	device_t	 dev;
57 	struct resource *sc_memr;
58 };
59 
60 static void nvbl_identify(driver_t *driver, device_t parent);
61 static int nvbl_probe(device_t dev);
62 static int nvbl_attach(device_t dev);
63 static int nvbl_setlevel(struct nvbl_softc *sc, int newlevel);
64 static int nvbl_getlevel(struct nvbl_softc *sc);
65 static int nvbl_sysctl(SYSCTL_HANDLER_ARGS);
66 
67 static 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 
75 static driver_t	nvbl_driver = {
76 	"backlight",
77 	nvbl_methods,
78 	sizeof(struct nvbl_softc)
79 };
80 
81 static devclass_t nvbl_devclass;
82 
83 DRIVER_MODULE(nvbl, vgapci, nvbl_driver, nvbl_devclass, 0, 0);
84 
85 static void
86 nvbl_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 
94 static int
95 nvbl_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 
117 static int
118 nvbl_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 
151 static int
152 nvbl_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 
172 static int
173 nvbl_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 
187 static int
188 nvbl_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