nvbl.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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__FBSDID("$FreeBSD: stable/11/sys/powerpc/powermac/nvbl.c 330897 2018-03-14 03:19:51Z eadler $");
31
32#include <sys/param.h>
33#include <sys/bus.h>
34#include <sys/systm.h>
35#include <sys/module.h>
36#include <sys/kernel.h>
37#include <sys/rman.h>
38#include <sys/sysctl.h>
39
40#include <machine/bus.h>
41
42#include <dev/ofw/openfirm.h>
43#include <dev/pci/pcivar.h>
44
45#define PCI_VENDOR_ID_NVIDIA	0x10de
46
47#define NVIDIA_BRIGHT_MIN     (0x0ec)
48#define NVIDIA_BRIGHT_MAX     (0x538)
49#define NVIDIA_BRIGHT_SCALE   ((NVIDIA_BRIGHT_MAX - NVIDIA_BRIGHT_MIN)/100)
50/* nVidia's MMIO registers are at PCI BAR[0] */
51#define NVIDIA_MMIO_PMC       (0x0)
52#define  NVIDIA_PMC_OFF         (NVIDIA_MMIO_PMC + 0x10f0)
53#define   NVIDIA_PMC_BL_SHIFT    (16)
54#define   NVIDIA_PMC_BL_EN       (1U << 31)
55
56
57struct nvbl_softc {
58	device_t	 dev;
59	struct resource *sc_memr;
60};
61
62static void nvbl_identify(driver_t *driver, device_t parent);
63static int nvbl_probe(device_t dev);
64static int nvbl_attach(device_t dev);
65static int nvbl_setlevel(struct nvbl_softc *sc, int newlevel);
66static int nvbl_getlevel(struct nvbl_softc *sc);
67static int nvbl_sysctl(SYSCTL_HANDLER_ARGS);
68
69static device_method_t nvbl_methods[] = {
70	/* Device interface */
71	DEVMETHOD(device_identify, nvbl_identify),
72	DEVMETHOD(device_probe, nvbl_probe),
73	DEVMETHOD(device_attach, nvbl_attach),
74	{0, 0},
75};
76
77static driver_t	nvbl_driver = {
78	"backlight",
79	nvbl_methods,
80	sizeof(struct nvbl_softc)
81};
82
83static devclass_t nvbl_devclass;
84
85DRIVER_MODULE(nvbl, vgapci, nvbl_driver, nvbl_devclass, 0, 0);
86
87static void
88nvbl_identify(driver_t *driver, device_t parent)
89{
90	if (OF_finddevice("mac-io/backlight") == -1)
91		return;
92	if (device_find_child(parent, "backlight", -1) == NULL)
93		device_add_child(parent, "backlight", -1);
94}
95
96static int
97nvbl_probe(device_t dev)
98{
99	char		control[8];
100	phandle_t	handle;
101
102	handle = OF_finddevice("mac-io/backlight");
103
104	if (handle == -1)
105		return (ENXIO);
106
107	if (OF_getprop(handle, "backlight-control", &control, sizeof(control)) < 0)
108		return (ENXIO);
109
110	if ((strcmp(control, "mnca") != 0) ||
111	    pci_get_vendor(device_get_parent(dev)) != PCI_VENDOR_ID_NVIDIA)
112		return (ENXIO);
113
114	device_set_desc(dev, "PowerBook backlight for nVidia graphics");
115
116	return (0);
117}
118
119static int
120nvbl_attach(device_t dev)
121{
122	struct nvbl_softc	*sc;
123	struct sysctl_ctx_list *ctx;
124	struct sysctl_oid *tree;
125	int			 rid;
126
127	sc = device_get_softc(dev);
128
129	rid = 0x10;	/* BAR[0], for the MMIO register */
130	sc->sc_memr = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
131			RF_ACTIVE | RF_SHAREABLE);
132	if (sc->sc_memr == NULL) {
133		device_printf(dev, "Could not alloc mem resource!\n");
134		return (ENXIO);
135	}
136
137	/* Turn on big-endian mode */
138	if (!(bus_read_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4) & 0x01000001)) {
139		bus_write_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4, 0x01000001);
140		mb();
141	}
142
143	ctx = device_get_sysctl_ctx(dev);
144	tree = device_get_sysctl_tree(dev);
145
146	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
147			"level", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
148			nvbl_sysctl, "I", "Backlight level (0-100)");
149
150	return (0);
151}
152
153static int
154nvbl_setlevel(struct nvbl_softc *sc, int newlevel)
155{
156	uint32_t pmc_reg;
157
158	if (newlevel > 100)
159		newlevel = 100;
160
161	if (newlevel < 0)
162		newlevel = 0;
163
164	if (newlevel > 0)
165		newlevel = (newlevel * NVIDIA_BRIGHT_SCALE) + NVIDIA_BRIGHT_MIN;
166
167	pmc_reg = bus_read_stream_4(sc->sc_memr, NVIDIA_PMC_OFF) & 0xffff;
168	pmc_reg |= NVIDIA_PMC_BL_EN | (newlevel << NVIDIA_PMC_BL_SHIFT);
169	bus_write_stream_4(sc->sc_memr, NVIDIA_PMC_OFF, pmc_reg);
170
171	return (0);
172}
173
174static int
175nvbl_getlevel(struct nvbl_softc *sc)
176{
177	uint16_t level;
178
179	level = bus_read_stream_2(sc->sc_memr, NVIDIA_PMC_OFF) & 0x7fff;
180
181	if (level  < NVIDIA_BRIGHT_MIN)
182		return 0;
183
184	level = (level - NVIDIA_BRIGHT_MIN) / NVIDIA_BRIGHT_SCALE;
185
186	return (level);
187}
188
189static int
190nvbl_sysctl(SYSCTL_HANDLER_ARGS)
191{
192	struct nvbl_softc *sc;
193	int newlevel, error;
194
195	sc = arg1;
196
197	newlevel = nvbl_getlevel(sc);
198
199	error = sysctl_handle_int(oidp, &newlevel, 0, req);
200
201	if (error || !req->newptr)
202		return (error);
203
204	return (nvbl_setlevel(sc, newlevel));
205}
206