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