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 const 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 backlight_properties props;
  98         struct fb_info *info = pci_get_drvdata(par->pci_dev);
  99         struct backlight_device *bd;
 100         char name[12];
 101
 102         if (!par->FlatPanel)
 103                 return;
 104
 105 #ifdef CONFIG_PMAC_BACKLIGHT
 106         if (!machine_is(powermac) ||
 107             !pmac_has_backlight_type("mnca"))
 108                 return;
 109 #endif
 110
 111         snprintf(name, sizeof(name), "nvidiabl%d", info->node);
 112
 113         memset(&props, 0, sizeof(struct backlight_properties));
 114         props.type = BACKLIGHT_RAW;
 115         props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
 116         bd = backlight_device_register(name, info->dev, par, &nvidia_bl_ops,
 117                                        &props);
 118         if (IS_ERR(bd)) {
 119                 info->bl_dev = NULL;
 120                 printk(KERN_WARNING "nvidia: Backlight registration failed\n");
 121                 goto error;
 122         }
 123
 124         info->bl_dev = bd;
 125         fb_bl_default_curve(info, 0,
 126                 0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL,
 127                 0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
 128
 129         bd->props.brightness = bd->props.max_brightness;
 130         bd->props.power = FB_BLANK_UNBLANK;
 131         backlight_update_status(bd);
 132
 133         printk("nvidia: Backlight initialized (%s)\n", name);
 134
 135         return;
 136
 137 error:
 138         return;
 139 }
 140
 141 void nvidia_bl_exit(struct nvidia_par *par)
 142 {
 143         struct fb_info *info = pci_get_drvdata(par->pci_dev);
 144         struct backlight_device *bd = info->bl_dev;
 145
 146         backlight_device_unregister(bd);
 147         printk("nvidia: Backlight unloaded\n");
 148 }