drivers/macintosh/via-pmu-backlight.c

   1 /*
   2  * Backlight code for via-pmu
   3  *
   4  * Copyright (C) 1998 Paul Mackerras and Fabio Riccardi.
   5  * Copyright (C) 2001-2002 Benjamin Herrenschmidt
   6  * Copyright (C) 2006      Michael Hanselmann <linux-kernel@hansmi.ch>
   7  *
   8  */
   9
  10 #include <asm/ptrace.h>
  11 #include <linux/adb.h>
  12 #include <linux/pmu.h>
  13 #include <asm/backlight.h>
  14 #include <asm/prom.h>
  15
  16 #define MAX_PMU_LEVEL 0xFF
  17
  18 static struct device_node *vias;
  19 static struct backlight_properties pmu_backlight_data;
  20
  21 static int pmu_backlight_get_level_brightness(struct fb_info *info,
  22                 int level)
  23 {
  24         int pmulevel;
  25
  26         /* Get and convert the value */
  27         mutex_lock(&info->bl_mutex);
  28         pmulevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
  29         mutex_unlock(&info->bl_mutex);
  30
  31         if (pmulevel < 0)
  32                 pmulevel = 0;
  33         else if (pmulevel > MAX_PMU_LEVEL)
  34                 pmulevel = MAX_PMU_LEVEL;
  35
  36         return pmulevel;
  37 }
  38
  39 static int pmu_backlight_update_status(struct backlight_device *bd)
  40 {
  41         struct fb_info *info = class_get_devdata(&bd->class_dev);
  42         struct adb_request req;
  43         int pmulevel, level = bd->props->brightness;
  44
  45         if (vias == NULL)
  46                 return -ENODEV;
  47
  48         if (bd->props->power != FB_BLANK_UNBLANK ||
  49             bd->props->fb_blank != FB_BLANK_UNBLANK)
  50                 level = 0;
  51
  52         pmulevel = pmu_backlight_get_level_brightness(info, level);
  53
  54         pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
  55         pmu_wait_complete(&req);
  56
  57         pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
  58                 PMU_POW_BACKLIGHT | (level > 0 ? PMU_POW_ON : PMU_POW_OFF));
  59         pmu_wait_complete(&req);
  60
  61         return 0;
  62 }
  63
  64 static int pmu_backlight_get_brightness(struct backlight_device *bd)
  65 {
  66         return bd->props->brightness;
  67 }
  68
  69 static struct backlight_properties pmu_backlight_data = {
  70         .owner          = THIS_MODULE,
  71         .get_brightness = pmu_backlight_get_brightness,
  72         .update_status  = pmu_backlight_update_status,
  73         .max_brightness = (FB_BACKLIGHT_LEVELS - 1),
  74 };
  75
  76 void __init pmu_backlight_init(struct device_node *in_vias)
  77 {
  78         struct backlight_device *bd;
  79         struct fb_info *info;
  80         char name[10];
  81         int level, autosave;
  82
  83         vias = in_vias;
  84
  85         /* Special case for the old PowerBook since I can't test on it */
  86         autosave =
  87                 machine_is_compatible("AAPL,3400/2400") ||
  88                 machine_is_compatible("AAPL,3500");
  89
  90         if (!autosave &&
  91             !pmac_has_backlight_type("pmu") &&
  92             !machine_is_compatible("AAPL,PowerBook1998") &&
  93             !machine_is_compatible("PowerBook1,1"))
  94                 return;
  95
  96         /* Actually, this is a hack, but I don't know of a better way
  97          * to get the first framebuffer device.
  98          */
  99         info = registered_fb[0];
 100         if (!info) {
 101                 printk("pmubl: No framebuffer found\n");
 102                 goto error;
 103         }
 104
 105         snprintf(name, sizeof(name), "pmubl%d", info->node);
 106
 107         bd = backlight_device_register(name, info, &pmu_backlight_data);
 108         if (IS_ERR(bd)) {
 109                 printk("pmubl: Backlight registration failed\n");
 110                 goto error;
 111         }
 112
 113         mutex_lock(&info->bl_mutex);
 114         info->bl_dev = bd;
 115         fb_bl_default_curve(info, 0x7F, 0x46, 0x0E);
 116         mutex_unlock(&info->bl_mutex);
 117
 118         level = pmu_backlight_data.max_brightness;
 119
 120         if (autosave) {
 121                 /* read autosaved value if available */
 122                 struct adb_request req;
 123                 pmu_request(&req, NULL, 2, 0xd9, 0);
 124                 pmu_wait_complete(&req);
 125
 126                 mutex_lock(&info->bl_mutex);
 127                 level = pmac_backlight_curve_lookup(info,
 128                                 (req.reply[0] >> 4) *
 129                                 pmu_backlight_data.max_brightness / 15);
 130                 mutex_unlock(&info->bl_mutex);
 131         }
 132
 133         up(&bd->sem);
 134         bd->props->brightness = level;
 135         bd->props->power = FB_BLANK_UNBLANK;
 136         bd->props->update_status(bd);
 137         down(&bd->sem);
 138
 139         mutex_lock(&pmac_backlight_mutex);
 140         if (!pmac_backlight)
 141                 pmac_backlight = bd;
 142         mutex_unlock(&pmac_backlight_mutex);
 143
 144         printk("pmubl: Backlight initialized (%s)\n", name);
 145
 146         return;
 147
 148 error:
 149         return;
 150 }