1/*
2 * Backlight code for nVidia based graphic cards
3 *
4 * Copyright 2004 Antonino Daplas <adaplas@pol.net>
5 * Copyright (c) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/backlight.h>
13#include <linux/fb.h>
14#include <linux/pci.h>
15
16#ifdef CONFIG_PMAC_BACKLIGHT
17#include <asm/backlight.h>
18#endif
19
20#include "nv_local.h"
21#include "nv_type.h"
22#include "nv_proto.h"
23
24/* We do not have any information about which values are allowed, thus
25 * we used safe values.
26 */
27#define MIN_LEVEL 0x158
28#define MAX_LEVEL 0x534
29#define LEVEL_STEP ((MAX_LEVEL - MIN_LEVEL) / FB_BACKLIGHT_MAX)
30
31static int nvidia_bl_get_level_brightness(struct nvidia_par *par,
32		int level)
33{
34	struct fb_info *info = pci_get_drvdata(par->pci_dev);
35	int nlevel;
36
37	/* Get and convert the value */
38	/* No locking of bl_curve since we read a single value */
39	nlevel = MIN_LEVEL + info->bl_curve[level] * LEVEL_STEP;
40
41	if (nlevel < 0)
42		nlevel = 0;
43	else if (nlevel < MIN_LEVEL)
44		nlevel = MIN_LEVEL;
45	else if (nlevel > MAX_LEVEL)
46		nlevel = MAX_LEVEL;
47
48	return nlevel;
49}
50
51static int nvidia_bl_update_status(struct backlight_device *bd)
52{
53	struct nvidia_par *par = bl_get_data(bd);
54	u32 tmp_pcrt, tmp_pmc, fpcontrol;
55	int level;
56
57	if (!par->FlatPanel)
58		return 0;
59
60	if (bd->props.power != FB_BLANK_UNBLANK ||
61	    bd->props.fb_blank != FB_BLANK_UNBLANK)
62		level = 0;
63	else
64		level = bd->props.brightness;
65
66	tmp_pmc = NV_RD32(par->PMC, 0x10F0) & 0x0000FFFF;
67	tmp_pcrt = NV_RD32(par->PCRTC0, 0x081C) & 0xFFFFFFFC;
68	fpcontrol = NV_RD32(par->PRAMDAC, 0x0848) & 0xCFFFFFCC;
69
70	if (level > 0) {
71		tmp_pcrt |= 0x1;
72		tmp_pmc |= (1 << 31); /* backlight bit */
73		tmp_pmc |= nvidia_bl_get_level_brightness(par, level) << 16;
74		fpcontrol |= par->fpSyncs;
75	} else
76		fpcontrol |= 0x20000022;
77
78	NV_WR32(par->PCRTC0, 0x081C, tmp_pcrt);
79	NV_WR32(par->PMC, 0x10F0, tmp_pmc);
80	NV_WR32(par->PRAMDAC, 0x848, fpcontrol);
81
82	return 0;
83}
84
85static const struct backlight_ops nvidia_bl_ops = {
86	.update_status	= nvidia_bl_update_status,
87};
88
89void nvidia_bl_init(struct nvidia_par *par)
90{
91	struct backlight_properties props;
92	struct fb_info *info = pci_get_drvdata(par->pci_dev);
93	struct backlight_device *bd;
94	char name[12];
95
96	if (!par->FlatPanel)
97		return;
98
99#ifdef CONFIG_PMAC_BACKLIGHT
100	if (!machine_is(powermac) ||
101	    !pmac_has_backlight_type("mnca"))
102		return;
103#endif
104
105	snprintf(name, sizeof(name), "nvidiabl%d", info->node);
106
107	memset(&props, 0, sizeof(struct backlight_properties));
108	props.type = BACKLIGHT_RAW;
109	props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
110	bd = backlight_device_register(name, info->dev, par, &nvidia_bl_ops,
111				       &props);
112	if (IS_ERR(bd)) {
113		info->bl_dev = NULL;
114		printk(KERN_WARNING "nvidia: Backlight registration failed\n");
115		goto error;
116	}
117
118	info->bl_dev = bd;
119	fb_bl_default_curve(info, 0,
120		0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL,
121		0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
122
123	bd->props.brightness = bd->props.max_brightness;
124	bd->props.power = FB_BLANK_UNBLANK;
125	backlight_update_status(bd);
126
127	printk("nvidia: Backlight initialized (%s)\n", name);
128
129	return;
130
131error:
132	return;
133}
134
135void nvidia_bl_exit(struct nvidia_par *par)
136{
137	struct fb_info *info = pci_get_drvdata(par->pci_dev);
138	struct backlight_device *bd = info->bl_dev;
139
140	backlight_device_unregister(bd);
141	printk("nvidia: Backlight unloaded\n");
142}
143