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