rockchip: on rk3399 enable Schmitt trigger on 32 kHz clock
If we don't enable the Schmitt trigger on the 32 kHz clock then systems
won't always resume from suspend properly. Presumably anything else in
the system that relies on the 32 kHz clock also will have problems
without the Schmitt trigger enabled.
Enable it always since having the 32 kHz clock on GPIO0_A0 isn't
exactly an optional feature, so all boards using rk3399 will need this.
Change-Id: Idc18c6cd1adc5be5f60efd9cb805d83d5cd40129
diff --git a/plat/rockchip/rk3399/drivers/pmu/pmu.c b/plat/rockchip/rk3399/drivers/pmu/pmu.c
index 9fc796c..00df085 100644
--- a/plat/rockchip/rk3399/drivers/pmu/pmu.c
+++ b/plat/rockchip/rk3399/drivers/pmu/pmu.c
@@ -1078,6 +1078,12 @@
CPU_BOOT_ADDR_WMASK);
mmio_write_32(PMU_BASE + PMU_NOC_AUTO_ENA, NOC_AUTO_ENABLE);
+ /*
+ * Enable Schmitt trigger for better 32 kHz input signal, which is
+ * important for suspend/resume reliability among other things.
+ */
+ mmio_write_32(PMUGRF_BASE + PMUGRF_GPIO0A_SMT, GPIO0A0_SMT_ENABLE);
+
init_pmu_counts();
nonboot_cpus_off();