1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Backlight code for nVidia based graphic cards
4 *
5 * Copyright 2004 Antonino Daplas <adaplas@pol.net>
6 * Copyright (c) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
7 */
8
9 #include <linux/backlight.h>
10 #include <linux/fb.h>
11 #include <linux/pci.h>
12
13 #ifdef CONFIG_PMAC_BACKLIGHT
14 #include <asm/backlight.h>
15 #endif
16
17 #include "nv_local.h"
18 #include "nv_type.h"
19 #include "nv_proto.h"
20
21 /* We do not have any information about which values are allowed, thus
22 * we used safe values.
23 */
24 #define MIN_LEVEL 0x158
25 #define MAX_LEVEL 0x534
26 #define LEVEL_STEP ((MAX_LEVEL - MIN_LEVEL) / FB_BACKLIGHT_MAX)
27
nvidia_bl_get_level_brightness(struct nvidia_par * par,int level)28 static int nvidia_bl_get_level_brightness(struct nvidia_par *par,
29 int level)
30 {
31 struct fb_info *info = pci_get_drvdata(par->pci_dev);
32 int nlevel;
33
34 /* Get and convert the value */
35 /* No locking of bl_curve since we read a single value */
36 nlevel = MIN_LEVEL + info->bl_curve[level] * LEVEL_STEP;
37
38 if (nlevel < 0)
39 nlevel = 0;
40 else if (nlevel < MIN_LEVEL)
41 nlevel = MIN_LEVEL;
42 else if (nlevel > MAX_LEVEL)
43 nlevel = MAX_LEVEL;
44
45 return nlevel;
46 }
47
nvidia_bl_update_status(struct backlight_device * bd)48 static int nvidia_bl_update_status(struct backlight_device *bd)
49 {
50 struct nvidia_par *par = bl_get_data(bd);
51 u32 tmp_pcrt, tmp_pmc, fpcontrol;
52 int level;
53
54 if (!par->FlatPanel)
55 return 0;
56
57 if (bd->props.power != FB_BLANK_UNBLANK ||
58 bd->props.fb_blank != FB_BLANK_UNBLANK)
59 level = 0;
60 else
61 level = bd->props.brightness;
62
63 tmp_pmc = NV_RD32(par->PMC, 0x10F0) & 0x0000FFFF;
64 tmp_pcrt = NV_RD32(par->PCRTC0, 0x081C) & 0xFFFFFFFC;
65 fpcontrol = NV_RD32(par->PRAMDAC, 0x0848) & 0xCFFFFFCC;
66
67 if (level > 0) {
68 tmp_pcrt |= 0x1;
69 tmp_pmc |= (1 << 31); /* backlight bit */
70 tmp_pmc |= nvidia_bl_get_level_brightness(par, level) << 16;
71 fpcontrol |= par->fpSyncs;
72 } else
73 fpcontrol |= 0x20000022;
74
75 NV_WR32(par->PCRTC0, 0x081C, tmp_pcrt);
76 NV_WR32(par->PMC, 0x10F0, tmp_pmc);
77 NV_WR32(par->PRAMDAC, 0x848, fpcontrol);
78
79 return 0;
80 }
81
82 static const struct backlight_ops nvidia_bl_ops = {
83 .update_status = nvidia_bl_update_status,
84 };
85
nvidia_bl_init(struct nvidia_par * par)86 void nvidia_bl_init(struct nvidia_par *par)
87 {
88 struct backlight_properties props;
89 struct fb_info *info = pci_get_drvdata(par->pci_dev);
90 struct backlight_device *bd;
91 char name[12];
92
93 if (!par->FlatPanel)
94 return;
95
96 #ifdef CONFIG_PMAC_BACKLIGHT
97 if (!machine_is(powermac) ||
98 !pmac_has_backlight_type("mnca"))
99 return;
100 #endif
101
102 snprintf(name, sizeof(name), "nvidiabl%d", info->node);
103
104 memset(&props, 0, sizeof(struct backlight_properties));
105 props.type = BACKLIGHT_RAW;
106 props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
107 bd = backlight_device_register(name, info->dev, par, &nvidia_bl_ops,
108 &props);
109 if (IS_ERR(bd)) {
110 info->bl_dev = NULL;
111 printk(KERN_WARNING "nvidia: Backlight registration failed\n");
112 goto error;
113 }
114
115 info->bl_dev = bd;
116 fb_bl_default_curve(info, 0,
117 0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL,
118 0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
119
120 bd->props.brightness = bd->props.max_brightness;
121 bd->props.power = FB_BLANK_UNBLANK;
122 backlight_update_status(bd);
123
124 printk("nvidia: Backlight initialized (%s)\n", name);
125
126 error:
127 return;
128 }
129
nvidia_bl_exit(struct nvidia_par * par)130 void nvidia_bl_exit(struct nvidia_par *par)
131 {
132 struct fb_info *info = pci_get_drvdata(par->pci_dev);
133 struct backlight_device *bd = info->bl_dev;
134
135 backlight_device_unregister(bd);
136 printk("nvidia: Backlight unloaded\n");
137 }
138