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 = class_get_devdata(&bd->class_dev);
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 int nvidia_bl_get_brightness(struct backlight_device *bd)
86{
87	return bd->props.brightness;
88}
89
90static struct backlight_ops nvidia_bl_ops = {
91	.get_brightness = nvidia_bl_get_brightness,
92	.update_status	= nvidia_bl_update_status,
93};
94
95void nvidia_bl_init(struct nvidia_par *par)
96{
97	struct fb_info *info = pci_get_drvdata(par->pci_dev);
98	struct backlight_device *bd;
99	char name[12];
100
101	if (!par->FlatPanel)
102		return;
103
104#ifdef CONFIG_PMAC_BACKLIGHT
105	if (!machine_is(powermac) ||
106	    !pmac_has_backlight_type("mnca"))
107		return;
108#endif
109
110	snprintf(name, sizeof(name), "nvidiabl%d", info->node);
111
112	bd = backlight_device_register(name, info->dev, par, &nvidia_bl_ops);
113	if (IS_ERR(bd)) {
114		info->bl_dev = NULL;
115		printk(KERN_WARNING "nvidia: Backlight registration failed\n");
116		goto error;
117	}
118
119	info->bl_dev = bd;
120	fb_bl_default_curve(info, 0,
121		0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL,
122		0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
123
124	bd->props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
125	bd->props.brightness = bd->props.max_brightness;
126	bd->props.power = FB_BLANK_UNBLANK;
127	backlight_update_status(bd);
128
129	printk("nvidia: Backlight initialized (%s)\n", name);
130
131	return;
132
133error:
134	return;
135}
136
137void nvidia_bl_exit(struct nvidia_par *par)
138{
139	struct fb_info *info = pci_get_drvdata(par->pci_dev);
140	struct backlight_device *bd = info->bl_dev;
141
142	backlight_device_unregister(bd);
143	printk("nvidia: Backlight unloaded\n");
144}
145