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 backlight_properties pmu_backlight_data;
  19 static spinlock_t pmu_backlight_lock;
  20 static int sleeping;
  21
  22 static int pmu_backlight_get_level_brightness(struct fb_info *info,
  23                 int level)
  24 {
  25         int pmulevel;
  26
  27         /* Get and convert the value */
  28         mutex_lock(&info->bl_mutex);
  29         pmulevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
  30         mutex_unlock(&info->bl_mutex);
  31
  32         if (pmulevel < 0)
  33                 pmulevel = 0;
  34         else if (pmulevel > MAX_PMU_LEVEL)
  35                 pmulevel = MAX_PMU_LEVEL;
  36
  37         return pmulevel;
  38 }
  39
  40 static int pmu_backlight_update_status(struct backlight_device *bd)
  41 {
  42         struct fb_info *info = class_get_devdata(&bd->class_dev);
  43         struct adb_request req;
  44         unsigned long flags;
  45         int level = bd->props->brightness;
  46
  47         spin_lock_irqsave(&pmu_backlight_lock, flags);
  48
  49         /* Don't update brightness when sleeping */
  50         if (sleeping)
  51                 goto out;
  52
  53         if (bd->props->power != FB_BLANK_UNBLANK ||
  54             bd->props->fb_blank != FB_BLANK_UNBLANK)
  55                 level = 0;
  56
  57         if (level > 0) {
  58                 int pmulevel = pmu_backlight_get_level_brightness(info, level);
  59
  60                 pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
  61                 pmu_wait_complete(&req);
  62
  63                 pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
  64                         PMU_POW_BACKLIGHT | PMU_POW_ON);
  65                 pmu_wait_complete(&req);
  66         } else {
  67                 pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
  68                         PMU_POW_BACKLIGHT | PMU_POW_OFF);
  69                 pmu_wait_complete(&req);
  70         }
  71
  72 out:
  73         spin_unlock_irqrestore(&pmu_backlight_lock, flags);
  74
  75         return 0;
  76 }
  77
  78 static int pmu_backlight_get_brightness(struct backlight_device *bd)
  79 {
  80         return bd->props->brightness;
  81 }
  82
  83 static struct backlight_properties pmu_backlight_data = {
  84         .owner          = THIS_MODULE,
  85         .get_brightness = pmu_backlight_get_brightness,
  86         .update_status  = pmu_backlight_update_status,
  87         .max_brightness = (FB_BACKLIGHT_LEVELS - 1),
  88 };
  89
  90 #ifdef CONFIG_PM
  91 static int pmu_backlight_sleep_call(struct pmu_sleep_notifier *self, int when)
  92 {
  93         unsigned long flags;
  94
  95         spin_lock_irqsave(&pmu_backlight_lock, flags);
  96
  97         switch (when) {
  98         case PBOOK_SLEEP_REQUEST:
  99                 sleeping = 1;
 100                 break;
 101         case PBOOK_WAKE:
 102                 sleeping = 0;
 103                 break;
 104         }
 105
 106         spin_unlock_irqrestore(&pmu_backlight_lock, flags);
 107
 108         return PBOOK_SLEEP_OK;
 109 }
 110
 111 static struct pmu_sleep_notifier pmu_backlight_sleep_notif = {
 112         .notifier_call = pmu_backlight_sleep_call,
 113 };
 114 #endif
 115
 116 void __init pmu_backlight_init()
 117 {
 118         struct backlight_device *bd;
 119         struct fb_info *info;
 120         char name[10];
 121         int level, autosave;
 122
 123         /* Special case for the old PowerBook since I can't test on it */
 124         autosave =
 125                 machine_is_compatible("AAPL,3400/2400") ||
 126                 machine_is_compatible("AAPL,3500");
 127
 128         if (!autosave &&
 129             !pmac_has_backlight_type("pmu") &&
 130             !machine_is_compatible("AAPL,PowerBook1998") &&
 131             !machine_is_compatible("PowerBook1,1"))
 132                 return;
 133
 134         /* Actually, this is a hack, but I don't know of a better way
 135          * to get the first framebuffer device.
 136          */
 137         info = registered_fb[0];
 138         if (!info) {
 139                 printk("pmubl: No framebuffer found\n");
 140                 goto error;
 141         }
 142
 143         snprintf(name, sizeof(name), "pmubl%d", info->node);
 144
 145         bd = backlight_device_register(name, info, &pmu_backlight_data);
 146         if (IS_ERR(bd)) {
 147                 printk("pmubl: Backlight registration failed\n");
 148                 goto error;
 149         }
 150
 151         mutex_lock(&info->bl_mutex);
 152         info->bl_dev = bd;
 153         fb_bl_default_curve(info, 0x7F, 0x46, 0x0E);
 154         mutex_unlock(&info->bl_mutex);
 155
 156         level = pmu_backlight_data.max_brightness;
 157
 158         if (autosave) {
 159                 /* read autosaved value if available */
 160                 struct adb_request req;
 161                 pmu_request(&req, NULL, 2, 0xd9, 0);
 162                 pmu_wait_complete(&req);
 163
 164                 mutex_lock(&info->bl_mutex);
 165                 level = pmac_backlight_curve_lookup(info,
 166                                 (req.reply[0] >> 4) *
 167                                 pmu_backlight_data.max_brightness / 15);
 168                 mutex_unlock(&info->bl_mutex);
 169         }
 170
 171         up(&bd->sem);
 172         bd->props->brightness = level;
 173         bd->props->power = FB_BLANK_UNBLANK;
 174         bd->props->update_status(bd);
 175         down(&bd->sem);
 176
 177         mutex_lock(&pmac_backlight_mutex);
 178         if (!pmac_backlight)
 179                 pmac_backlight = bd;
 180         mutex_unlock(&pmac_backlight_mutex);
 181
 182 #ifdef CONFIG_PM
 183         pmu_register_sleep_notifier(&pmu_backlight_sleep_notif);
 184 #endif
 185
 186         printk("pmubl: Backlight initialized (%s)\n", name);
 187
 188         return;
 189
 190 error:
 191         return;
 192 }