ahci: pp->active_link is not reliable when FBS is enabled
[kernel.git] / drivers / video / nvidia / nv_backlight.c
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
31 static 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
51 static 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
85 static int nvidia_bl_get_brightness(struct backlight_device *bd)
86 {
87         return bd->props.brightness;
88 }
89
90 static struct backlight_ops nvidia_bl_ops = {
91         .get_brightness = nvidia_bl_get_brightness,
92         .update_status  = nvidia_bl_update_status,
93 };
94
95 void 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
133 error:
134         return;
135 }
136
137 void 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 }