arch/ppc/platforms/pmac_backlight.c

   1 /*
   2  * Miscellaneous procedures for dealing with the PowerMac hardware.
   3  * Contains support for the backlight.
   4  *
   5  *   Copyright (C) 2000 Benjamin Herrenschmidt
   6  *
   7  */
   8
   9 #include <linux/config.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/stddef.h>
  13 #include <linux/reboot.h>
  14 #include <linux/nvram.h>
  15 #include <asm/sections.h>
  16 #include <asm/ptrace.h>
  17 #include <asm/io.h>
  18 #include <asm/pgtable.h>
  19 #include <asm/system.h>
  20 #include <asm/prom.h>
  21 #include <asm/machdep.h>
  22 #include <asm/nvram.h>
  23 #include <asm/backlight.h>
  24
  25 #include <linux/adb.h>
  26 #include <linux/pmu.h>
  27
  28 static struct backlight_controller *backlighter = NULL;
  29 static void* backlighter_data = NULL;
  30 static int backlight_autosave = 0;
  31 static int backlight_level = BACKLIGHT_MAX;
  32 static int backlight_enabled = 1;
  33
  34 void __pmac
  35 register_backlight_controller(struct backlight_controller *ctrler, void *data, char *type)
  36 {
  37         struct device_node* bk_node;
  38         char *prop;
  39         int valid = 0;
  40
  41         /* There's already a matching controller, bail out */
  42         if (backlighter != NULL)
  43                 return;
  44
  45         bk_node = find_devices("backlight");
  46
  47 #ifdef CONFIG_ADB_PMU
  48         /* Special case for the old PowerBook since I can't test on it */
  49         backlight_autosave = machine_is_compatible("AAPL,3400/2400")
  50                 || machine_is_compatible("AAPL,3500");
  51         if ((backlight_autosave
  52              || machine_is_compatible("AAPL,PowerBook1998")
  53              || machine_is_compatible("PowerBook1,1"))
  54             && !strcmp(type, "pmu"))
  55                 valid = 1;
  56 #endif
  57         if (bk_node) {
  58                 prop = get_property(bk_node, "backlight-control", NULL);
  59                 if (prop && !strncmp(prop, type, strlen(type)))
  60                         valid = 1;
  61         }
  62         if (!valid)
  63                 return;
  64         backlighter = ctrler;
  65         backlighter_data = data;
  66
  67         if (bk_node && !backlight_autosave)
  68                 prop = get_property(bk_node, "bklt", NULL);
  69         else
  70                 prop = NULL;
  71         if (prop) {
  72                 backlight_level = ((*prop)+1) >> 1;
  73                 if (backlight_level > BACKLIGHT_MAX)
  74                         backlight_level = BACKLIGHT_MAX;
  75         }
  76
  77 #ifdef CONFIG_ADB_PMU
  78         if (backlight_autosave) {
  79                 struct adb_request req;
  80                 pmu_request(&req, NULL, 2, 0xd9, 0);
  81                 while (!req.complete)
  82                         pmu_poll();
  83                 backlight_level = req.reply[0] >> 4;
  84         }
  85 #endif
  86         if (!backlighter->set_enable(1, backlight_level, data))
  87                 backlight_enabled = 1;
  88
  89         printk(KERN_INFO "Registered \"%s\" backlight controller, level: %d/15\n",
  90                 type, backlight_level);
  91 }
  92 EXPORT_SYMBOL(register_backlight_controller);
  93
  94 void __pmac
  95 unregister_backlight_controller(struct backlight_controller *ctrler, void *data)
  96 {
  97         /* We keep the current backlight level (for now) */
  98         if (ctrler == backlighter && data == backlighter_data)
  99                 backlighter = NULL;
 100 }
 101 EXPORT_SYMBOL(unregister_backlight_controller);
 102
 103 int __pmac
 104 set_backlight_enable(int enable)
 105 {
 106         int rc;
 107
 108         if (!backlighter)
 109                 return -ENODEV;
 110         rc = backlighter->set_enable(enable, backlight_level, backlighter_data);
 111         if (!rc)
 112                 backlight_enabled = enable;
 113         return rc;
 114 }
 115 EXPORT_SYMBOL(set_backlight_enable);
 116
 117 int __pmac
 118 get_backlight_enable(void)
 119 {
 120         if (!backlighter)
 121                 return -ENODEV;
 122         return backlight_enabled;
 123 }
 124 EXPORT_SYMBOL(get_backlight_enable);
 125
 126 int __pmac
 127 set_backlight_level(int level)
 128 {
 129         int rc = 0;
 130
 131         if (!backlighter)
 132                 return -ENODEV;
 133         if (level < BACKLIGHT_MIN)
 134                 level = BACKLIGHT_OFF;
 135         if (level > BACKLIGHT_MAX)
 136                 level = BACKLIGHT_MAX;
 137         if (backlight_enabled)
 138                 rc = backlighter->set_level(level, backlighter_data);
 139         if (!rc)
 140                 backlight_level = level;
 141         if (!rc && !backlight_autosave) {
 142                 level <<=1;
 143                 if (level & 0x10)
 144                         level |= 0x01;
 145                 // -- todo: save to property "bklt"
 146         }
 147         return rc;
 148 }
 149 EXPORT_SYMBOL(set_backlight_level);
 150
 151 int __pmac
 152 get_backlight_level(void)
 153 {
 154         if (!backlighter)
 155                 return -ENODEV;
 156         return backlight_level;
 157 }
 158 EXPORT_SYMBOL(get_backlight_level);