rpi3: Prepare for supporting a GIC (in RPi4)

As the PSCI "power" management functions for the Raspberry Pi 3 port
will be shared with the upcoming RPi4 support, we need to prepare them
for dealing with the GIC interrupt controller.
Splitting this code just for those simple calls to the generic GIC
routines does not seem worthwhile, so just use a #define the protect the
GIC code from being included by the existing RPi3 code.

Change-Id: Iaca6b0214563852b28ad4a088ec45348ae8be40d
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/plat/rpi/common/rpi3_pm.c b/plat/rpi/common/rpi3_pm.c
index b79e273..8c2d070 100644
--- a/plat/rpi/common/rpi3_pm.c
+++ b/plat/rpi/common/rpi3_pm.c
@@ -17,6 +17,10 @@
 
 #include <rpi_hw.h>
 
+#ifdef RPI_HAVE_GIC
+#include <drivers/arm/gicv2.h>
+#endif
+
 /* Make composite power state parameter till power level 0 */
 #if PSCI_EXTENDED_STATE_ID
 
@@ -112,6 +116,13 @@
 	wfi();
 }
 
+static void rpi3_pwr_domain_off(const psci_power_state_t *target_state)
+{
+#ifdef RPI_HAVE_GIC
+	gicv2_cpuif_disable();
+#endif
+}
+
 /*******************************************************************************
  * Platform handler called when a power domain is about to be turned on. The
  * mpidr determines the CPU to be turned on.
@@ -144,6 +155,11 @@
 {
 	assert(target_state->pwr_domain_state[MPIDR_AFFLVL0] ==
 					PLAT_LOCAL_STATE_OFF);
+
+#ifdef RPI_HAVE_GIC
+	gicv2_pcpu_distif_init();
+	gicv2_cpuif_enable();
+#endif
 }
 
 /*******************************************************************************
@@ -207,6 +223,7 @@
  ******************************************************************************/
 static const plat_psci_ops_t plat_rpi3_psci_pm_ops = {
 	.cpu_standby = rpi3_cpu_standby,
+	.pwr_domain_off = rpi3_pwr_domain_off,
 	.pwr_domain_on = rpi3_pwr_domain_on,
 	.pwr_domain_on_finish = rpi3_pwr_domain_on_finish,
 	.system_off = rpi3_system_off,