arch/arm/mach-rockchip/rk_system_status.c

   1 #include <linux/mutex.h>
   2 #include <linux/notifier.h>
   3
   4 static unsigned long system_status = 0;
   5 static unsigned long ref_count[32] = {0};
   6 static DEFINE_MUTEX(system_status_mutex);
   7
   8 static BLOCKING_NOTIFIER_HEAD(rk_system_status_chain_head);
   9
  10 int rockchip_register_system_status_notifier(struct notifier_block *nb)
  11 {
  12         return blocking_notifier_chain_register(&rk_system_status_chain_head, nb);
  13 }
  14 EXPORT_SYMBOL_GPL(rockchip_register_system_status_notifier);
  15
  16 int rockchip_unregister_system_status_notifier(struct notifier_block *nb)
  17 {
  18         return blocking_notifier_chain_unregister(&rk_system_status_chain_head, nb);
  19 }
  20 EXPORT_SYMBOL_GPL(rockchip_unregister_system_status_notifier);
  21
  22 static int rockchip_system_status_notifier_call_chain(unsigned long val)
  23 {
  24         int ret = blocking_notifier_call_chain(&rk_system_status_chain_head, val, NULL);
  25
  26         return notifier_to_errno(ret);
  27 }
  28
  29 int rockchip_set_system_status(unsigned long status)
  30 {
  31         unsigned long old_system_status;
  32         unsigned int single_status_offset;
  33
  34         mutex_lock(&system_status_mutex);
  35
  36         old_system_status = system_status;
  37
  38         while (status) {
  39                 single_status_offset = fls(status) - 1;
  40                 status &= ~(1<<single_status_offset);
  41                 if (ref_count[single_status_offset] == 0) {
  42                         system_status |= 1 << single_status_offset;
  43                 }
  44                 ref_count[single_status_offset]++;
  45         }
  46         if (old_system_status != system_status)
  47                 rockchip_system_status_notifier_call_chain(system_status);
  48
  49         mutex_unlock(&system_status_mutex);
  50         return 0;
  51 }
  52
  53 int rockchip_clear_system_status(unsigned long status)
  54 {
  55         unsigned long old_system_status;
  56         unsigned int single_status_offset;
  57         mutex_lock(&system_status_mutex);
  58
  59         old_system_status = system_status;
  60
  61         while (status) {
  62                 single_status_offset = fls(status) - 1;
  63                 status &= ~(1<<single_status_offset);
  64                 if (ref_count[single_status_offset] == 0) {
  65                         continue;
  66                 } else {
  67                         if (ref_count[single_status_offset] == 1) {
  68                                 system_status &= ~(1<<single_status_offset);
  69                         }
  70                         ref_count[single_status_offset]--;
  71                 }
  72         }
  73         if (old_system_status != system_status)
  74                 rockchip_system_status_notifier_call_chain(system_status);
  75
  76         mutex_unlock(&system_status_mutex);
  77
  78         return 0;
  79 }
  80
  81 unsigned long rockchip_get_system_status(void)
  82 {
  83         unsigned long ret;
  84
  85         mutex_lock(&system_status_mutex);
  86         ret = system_status;
  87         mutex_unlock(&system_status_mutex);
  88
  89         return ret;
  90 }