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 #include "nv_local.h"
  16 #include "nv_type.h"
  17 #include "nv_proto.h"
  18
  19 /* We do not have any information about which values are allowed, thus
  20  * we used safe values.
  21  */
  22 #define MIN_LEVEL 0x158
  23 #define MAX_LEVEL 0x534
  24 #define LEVEL_STEP ((MAX_LEVEL - MIN_LEVEL) / FB_BACKLIGHT_MAX)
  25
  26 static int nvidia_bl_get_level_brightness(struct nvidia_par *par,
  27                 int level)
  28 {
  29         struct fb_info *info = pci_get_drvdata(par->pci_dev);
  30         int nlevel;
  31
  32         /* Get and convert the value */
  33         /* No locking of bl_curve since we read a single value */
  34         nlevel = MIN_LEVEL + info->bl_curve[level] * LEVEL_STEP;
  35
  36         if (nlevel < 0)
  37                 nlevel = 0;
  38         else if (nlevel < MIN_LEVEL)
  39                 nlevel = MIN_LEVEL;
  40         else if (nlevel > MAX_LEVEL)
  41                 nlevel = MAX_LEVEL;
  42
  43         return nlevel;
  44 }
  45
  46 static int nvidia_bl_update_status(struct backlight_device *bd)
  47 {
  48         struct nvidia_par *par = class_get_devdata(&bd->class_dev);
  49         u32 tmp_pcrt, tmp_pmc, fpcontrol;
  50         int level;
  51
  52         if (!par->FlatPanel)
  53                 return 0;
  54
  55         if (bd->props.power != FB_BLANK_UNBLANK ||
  56             bd->props.fb_blank != FB_BLANK_UNBLANK)
  57                 level = 0;
  58         else
  59                 level = bd->props.brightness;
  60
  61         tmp_pmc = NV_RD32(par->PMC, 0x10F0) & 0x0000FFFF;
  62         tmp_pcrt = NV_RD32(par->PCRTC0, 0x081C) & 0xFFFFFFFC;
  63         fpcontrol = NV_RD32(par->PRAMDAC, 0x0848) & 0xCFFFFFCC;
  64
  65         if (level > 0) {
  66                 tmp_pcrt |= 0x1;
  67                 tmp_pmc |= (1 << 31); /* backlight bit */
  68                 tmp_pmc |= nvidia_bl_get_level_brightness(par, level) << 16;
  69                 fpcontrol |= par->fpSyncs;
  70         } else
  71                 fpcontrol |= 0x20000022;
  72
  73         NV_WR32(par->PCRTC0, 0x081C, tmp_pcrt);
  74         NV_WR32(par->PMC, 0x10F0, tmp_pmc);
  75         NV_WR32(par->PRAMDAC, 0x848, fpcontrol);
  76
  77         return 0;
  78 }
  79
  80 static int nvidia_bl_get_brightness(struct backlight_device *bd)
  81 {
  82         return bd->props.brightness;
  83 }
  84
  85 static struct backlight_ops nvidia_bl_ops = {
  86         .get_brightness = nvidia_bl_get_brightness,
  87         .update_status  = nvidia_bl_update_status,
  88 };
  89
  90 void nvidia_bl_init(struct nvidia_par *par)
  91 {
  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         bd = backlight_device_register(name, info->dev, par, &nvidia_bl_ops);
 108         if (IS_ERR(bd)) {
 109                 info->bl_dev = NULL;
 110                 printk(KERN_WARNING "nvidia: Backlight registration failed\n");
 111                 goto error;
 112         }
 113
 114         info->bl_dev = bd;
 115         fb_bl_default_curve(info, 0,
 116                 0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL,
 117                 0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
 118
 119         bd->props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
 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         return;
 127
 128 error:
 129         return;
 130 }
 131
 132 void nvidia_bl_exit(struct nvidia_par *par)
 133 {
 134         struct fb_info *info = pci_get_drvdata(par->pci_dev);
 135         struct backlight_device *bd = info->bl_dev;
 136
 137         backlight_device_unregister(bd);
 138         printk("nvidia: Backlight unloaded\n");
 139 }