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131 lines · 3.1 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Backlight code for nVidia based graphic cards
4 *
5 * Copyright 2004 Antonino Daplas <[email protected]>
6 * Copyright (c) 2006 Michael Hanselmann <[email protected]>
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
28static 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
48static 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 = backlight_get_brightness(bd);
53
54 if (!par->FlatPanel)
55 return 0;
56
57 tmp_pmc = NV_RD32(par->PMC, 0x10F0) & 0x0000FFFF;
58 tmp_pcrt = NV_RD32(par->PCRTC0, 0x081C) & 0xFFFFFFFC;
59 fpcontrol = NV_RD32(par->PRAMDAC, 0x0848) & 0xCFFFFFCC;
60
61 if (level > 0) {
62 tmp_pcrt |= 0x1;
63 tmp_pmc |= (1 << 31); /* backlight bit */
64 tmp_pmc |= nvidia_bl_get_level_brightness(par, level) << 16;
65 fpcontrol |= par->fpSyncs;
66 } else
67 fpcontrol |= 0x20000022;
68
69 NV_WR32(par->PCRTC0, 0x081C, tmp_pcrt);
70 NV_WR32(par->PMC, 0x10F0, tmp_pmc);
71 NV_WR32(par->PRAMDAC, 0x848, fpcontrol);
72
73 return 0;
74}
75
76static const struct backlight_ops nvidia_bl_ops = {
77 .update_status = nvidia_bl_update_status,
78};
79
80void nvidia_bl_init(struct nvidia_par *par)
81{
82 struct backlight_properties props;
83 struct fb_info *info = pci_get_drvdata(par->pci_dev);
84 struct backlight_device *bd;
85 char name[12];
86
87 if (!par->FlatPanel)
88 return;
89
90#ifdef CONFIG_PMAC_BACKLIGHT
91 if (!machine_is(powermac) ||
92 !pmac_has_backlight_type("mnca"))
93 return;
94#endif
95
96 snprintf(name, sizeof(name), "nvidiabl%d", info->node);
97
98 memset(&props, 0, sizeof(struct backlight_properties));
99 props.type = BACKLIGHT_RAW;
100 props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
101 bd = backlight_device_register(name, info->device, par, &nvidia_bl_ops,
102 &props);
103 if (IS_ERR(bd)) {
104 info->bl_dev = NULL;
105 printk(KERN_WARNING "nvidia: Backlight registration failed\n");
106 goto error;
107 }
108
109 info->bl_dev = bd;
110 fb_bl_default_curve(info, 0,
111 0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL,
112 0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
113
114 bd->props.brightness = bd->props.max_brightness;
115 bd->props.power = BACKLIGHT_POWER_ON;
116 backlight_update_status(bd);
117
118 printk("nvidia: Backlight initialized (%s)\n", name);
119
120error:
121 return;
122}
123
124void nvidia_bl_exit(struct nvidia_par *par)
125{
126 struct fb_info *info = pci_get_drvdata(par->pci_dev);
127 struct backlight_device *bd = info->bl_dev;
128
129 backlight_device_unregister(bd);
130 printk("nvidia: Backlight unloaded\n");
131}