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| author | Vikram Kanigiri <vikram.kanigiri@arm.com> | 2014-07-01 15:34:11 +0100 |
|---|---|---|
| committer | Vikram Kanigiri <vikram.kanigiri@arm.com> | 2014-10-21 11:39:27 +0100 |
| commit | fc680456cf5507a8f5267f5cc44283fb7ad404e6 (patch) | |
| tree | 37ba3eaf02168d0298ac8f6e4f9fec3bbfbead4b | |
| parent | 7e998c42ce1ffa16101cc712a3b914c311e29788 (diff) | |
Juno: Support entry into a standby state
This patch adds support on the Juno platform for entering a wfi in
response to a PSCI CPU_SUSPEND call where the state type is a
standby state.
Change-Id: I0a102dee1f8d2ad936c63ad1d1d3ad001a4a4768
| -rw-r--r-- | plat/juno/plat_pm.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/plat/juno/plat_pm.c b/plat/juno/plat_pm.c index 74ce89fd..a3f6bdd5 100644 --- a/plat/juno/plat_pm.c +++ b/plat/juno/plat_pm.c @@ -275,12 +275,47 @@ static void __dead2 juno_system_reset(void) } /******************************************************************************* + * Handler called when an affinity instance is about to enter standby. + ******************************************************************************/ +int32_t juno_affinst_standby(unsigned int power_state) +{ + unsigned int target_afflvl; + unsigned int scr; + + /* Sanity check the requested state */ + target_afflvl = psci_get_pstate_afflvl(power_state); + + /* + * It's possible to enter standby only on affinity level 0 i.e. a cpu + * on the Juno. Ignore any other affinity level. + */ + if (target_afflvl != MPIDR_AFFLVL0) + return PSCI_E_INVALID_PARAMS; + + scr = read_scr_el3(); + /* Enable PhysicalIRQ bit for NS world to wake the CPU */ + write_scr_el3(scr | SCR_IRQ_BIT); + isb(); + dsb(); + wfi(); + + /* + * Restore SCR to the original value, synchronisation of scr_el3 is + * done by eret while el3_exit to save some execution cycles. + */ + write_scr_el3(scr); + + return PSCI_E_SUCCESS; +} + +/******************************************************************************* * Export the platform handlers to enable psci to invoke them ******************************************************************************/ static const plat_pm_ops_t juno_ops = { .affinst_on = juno_affinst_on, .affinst_on_finish = juno_affinst_on_finish, .affinst_off = juno_affinst_off, + .affinst_standby = juno_affinst_standby, .affinst_suspend = juno_affinst_suspend, .affinst_suspend_finish = juno_affinst_suspend_finish, .system_off = juno_system_off, |