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
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 = FB_BLANK_UNBLANK;
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}
132