atibl.c revision 239548 
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: head/sys/powerpc/powermac/atibl.c 239548 2012-08-21 23:55:29Z jhibbits $");
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
42/* From the xf86-video-ati driver's radeon_reg.h */
43#define RADEON_LVDS_GEN_CNTL         0x02d0
44#define  RADEON_LVDS_ON               (1   <<  0)
45#define  RADEON_LVDS_DISPLAY_DIS      (1   <<  1)
46#define  RADEON_LVDS_PANEL_TYPE       (1   <<  2)
47#define  RADEON_LVDS_PANEL_FORMAT     (1   <<  3)
48#define  RADEON_LVDS_RST_FM           (1   <<  6)
49#define  RADEON_LVDS_EN               (1   <<  7)
50#define  RADEON_LVDS_BL_MOD_LEVEL_SHIFT 8
51#define  RADEON_LVDS_BL_MOD_LEVEL_MASK (0xff << 8)
52#define  RADEON_LVDS_BL_MOD_EN        (1   << 16)
53#define  RADEON_LVDS_DIGON            (1   << 18)
54#define  RADEON_LVDS_BLON             (1   << 19)
55
56struct atibl_softc {
57	device_t	 dev;
58	struct resource *sc_memr;
59};
60
61static void atibl_identify(driver_t *driver, device_t parent);
62static int atibl_probe(device_t dev);
63static int atibl_attach(device_t dev);
64static int atibl_setlevel(struct atibl_softc *sc, int newlevel);
65static int atibl_getlevel(struct atibl_softc *sc);
66static int atibl_sysctl(SYSCTL_HANDLER_ARGS);
67
68static device_method_t atibl_methods[] = {
69	/* Device interface */
70	DEVMETHOD(device_identify, atibl_identify),
71	DEVMETHOD(device_probe, atibl_probe),
72	DEVMETHOD(device_attach, atibl_attach),
73	{0, 0},
74};
75
76static driver_t	atibl_driver = {
77	"backlight",
78	atibl_methods,
79	sizeof(struct atibl_softc)
80};
81
82static devclass_t atibl_devclass;
83
84DRIVER_MODULE(atibl, vgapci, atibl_driver, atibl_devclass, 0, 0);
85
86static void
87atibl_identify(driver_t *driver, device_t parent)
88{
89	if (device_find_child(parent, "backlight", -1) == NULL)
90		device_add_child(parent, "backlight", -1);
91}
92
93static int
94atibl_probe(device_t dev)
95{
96	char		control[8];
97	phandle_t	handle;
98
99	handle = OF_finddevice("mac-io/backlight");
100
101	if (handle == -1)
102		return (ENXIO);
103
104	if (OF_getprop(handle, "backlight-control", &control, sizeof(control)) < 0)
105		return (ENXIO);
106
107	if (strcmp(control, "ati") != 0)
108		return (ENXIO);
109
110	device_set_desc(dev, "PowerBook backlight for ATI graphics");
111
112	return (0);
113}
114
115static int
116atibl_attach(device_t dev)
117{
118	struct atibl_softc	*sc;
119	struct sysctl_ctx_list *ctx;
120	struct sysctl_oid *tree;
121	int			 rid;
122
123	sc = device_get_softc(dev);
124
125	rid = 0x18;	/* BAR[2], for the MMIO register */
126	sc->sc_memr = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
127			RF_ACTIVE | RF_SHAREABLE);
128	if (sc->sc_memr == NULL) {
129		device_printf(dev, "Could not alloc mem resource!\n");
130		return (ENXIO);
131	}
132
133	ctx = device_get_sysctl_ctx(dev);
134	tree = device_get_sysctl_tree(dev);
135
136	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
137			"level", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
138			atibl_sysctl, "I", "Backlight level (0-100)");
139
140	return (0);
141}
142
143static int
144atibl_setlevel(struct atibl_softc *sc, int newlevel)
145{
146	uint32_t lvds_gen_cntl;
147
148	if (newlevel > 100)
149		newlevel = 100;
150
151	if (newlevel < 0)
152		newlevel = 0;
153
154	newlevel = (newlevel * 5) / 2 + 5;
155	lvds_gen_cntl = bus_read_4(sc->sc_memr, RADEON_LVDS_GEN_CNTL);
156	lvds_gen_cntl |= RADEON_LVDS_BL_MOD_EN;
157	lvds_gen_cntl &= ~RADEON_LVDS_BL_MOD_LEVEL_MASK;
158	lvds_gen_cntl |= (newlevel << RADEON_LVDS_BL_MOD_LEVEL_SHIFT) &
159		RADEON_LVDS_BL_MOD_LEVEL_MASK;
160	bus_write_4(sc->sc_memr, RADEON_LVDS_GEN_CNTL, lvds_gen_cntl);
161
162	return (0);
163}
164
165static int
166atibl_getlevel(struct atibl_softc *sc)
167{
168	uint32_t	lvds_gen_cntl;
169	int			level;
170
171	lvds_gen_cntl = bus_read_4(sc->sc_memr, RADEON_LVDS_GEN_CNTL);
172
173	level = ((lvds_gen_cntl & RADEON_LVDS_BL_MOD_LEVEL_MASK) >>
174			RADEON_LVDS_BL_MOD_LEVEL_SHIFT);
175	level = ((level - 5) * 2) / 5;
176
177	return (level);
178}
179
180static int
181atibl_sysctl(SYSCTL_HANDLER_ARGS)
182{
183	struct atibl_softc *sc;
184	int newlevel, error;
185
186	sc = arg1;
187
188	newlevel = atibl_getlevel(sc);
189
190	error = sysctl_handle_int(oidp, &newlevel, 0, req);
191
192	if (error || !req->newptr)
193		return (error);
194
195	return (atibl_setlevel(sc, newlevel));
196}
197