andrius
/
arm-trusted-firmware
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

juno: Implement PM ops to power down CPUs 

Signed-off-by: Jon Medhurst <tixy@linaro.org>
This commit is contained in:
Jon Medhurst 2014-02-11 14:07:59 +00:00 committed by Sandrine Bailleux
parent 7441ac3a24
commit a0d586ea45
1 changed files with 51 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
plat/juno/plat_pm.c
View File

@ -93,12 +93,62 @@ int pm_on_finish(unsigned long mpidr, unsigned int afflvl, unsigned int state)
return PSCI_E_SUCCESS;
}
/*******************************************************************************
* Handler called when an affinity instance is about to be turned off. The
* level and mpidr determine the affinity instance. The 'state' arg. allows the
* platform to decide whether the cluster is being turned off and take apt
* actions.
*
* CAUTION: This function is called with coherent stacks so that caches can be
* turned off, flushed and coherency disabled. There is no guarantee that caches
* will remain turned on across calls to this function as each affinity level is
* dealt with. So do not write & read global variables across calls. It will be
* wise to do flush a write to the global to prevent unpredictable results.
******************************************************************************/
int pm_off(unsigned long mpidr, unsigned int afflvl, unsigned int state)
{
/* We're only interested in power off states */
if (state != PSCI_STATE_OFF)
return PSCI_E_SUCCESS;
switch (afflvl) {
case MPIDR_AFFLVL1:
/* Cluster is to be turned off, so disable coherency */
cci_disable_coherency(mpidr);
break;
case MPIDR_AFFLVL0:
/* Turn off intra-cluster coherency */
write_cpuectlr(read_cpuectlr() & ~CPUECTLR_SMP_BIT);
/* Prevent interrupts from spuriously waking up this cpu */
gic_cpuif_deactivate(GICC_BASE);
/*
* Ask SCP to power down CPU.
*
* Note, we also ask for cluster power down as well because we
* know the SCP will only actually do that if this is the last
* CPU going down, and also, that final power down won't happen
* until this CPU executes the WFI instruction after the PSCI
* framework has done it's thing.
*/
scpi_set_css_power_state(mpidr, scpi_power_off, scpi_power_off,
scpi_power_retention);
break;
}
return PSCI_E_SUCCESS;
}
/*******************************************************************************
* Export the platform handlers to enable psci to invoke them
******************************************************************************/
static plat_pm_ops pm_ops = {
.affinst_on = pm_on,
.affinst_on_finish = pm_on_finish
.affinst_on_finish = pm_on_finish,
.affinst_off = pm_off
};
/*******************************************************************************