/*
* Set the DDR, AHB to 24MHz.
* This mode will be activated only when none of the modules that
* need a higher DDR or AHB frequency are active.
*/
int set_low_bus_freq(void)
{
if (busfreq_suspended)
return 0;
if (!bus_freq_scaling_initialized || !bus_freq_scaling_is_active)
return 0;
/*
* Check to see if we need to got from
* low bus freq mode to audio bus freq mode.
* If so, the change needs to be done immediately.
*/
if (audio_bus_count && (low_bus_freq_mode || ultra_low_bus_freq_mode))
reduce_bus_freq();
else
/*
* Don't lower the frequency immediately. Instead
* scheduled a delayed work and drop the freq if
* the conditions still remain the same.
*/
schedule_delayed_work(&low_bus_freq_handler,
usecs_to_jiffies(3000000));
return 0;
}
static void reduce_bus_freq_handler(struct work_struct *work)
{
mutex_lock(&bus_freq_mutex);
if (!low_freq_bus_used()) {
mutex_unlock(&bus_freq_mutex);
return;
}
/* If we are already in audio bus freq mode,
* just return if lp_audio_freq is true.
*/
if (audio_bus_freq_mode && lp_audio_freq) {
mutex_unlock(&bus_freq_mutex);
return;
}
/* If we dont want to transition from low bus to
* audio bus mode and are already in
*low bus mode, then return.
*/
if (!lp_audio_freq && low_bus_freq_mode) {
mutex_unlock(&bus_freq_mutex);
return;
}
reduce_bus_freq();
mutex_unlock(&bus_freq_mutex);
}
static void reduce_bus_freq_handler(struct work_struct *work)
{
mutex_lock(&bus_freq_mutex);
reduce_bus_freq();
mutex_unlock(&bus_freq_mutex);
}
