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 9fc796cc4e93672dc0832c8fecca6e45e7fbf0c0..00df0858d9e82dfa2d9d7da26c2ecce46777ab81 100644 (file)
--- a/plat/rockchip/rk3399/drivers/pmu/pmu.c
+++ b/plat/rockchip/rk3399/drivers/pmu/pmu.c
@@ -1078,6 +1078,12 @@ void plat_rockchip_pmu_init(void)
                      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();

diff --git a/plat/rockchip/rk3399/drivers/pmu/pmu.h b/plat/rockchip/rk3399/drivers/pmu/pmu.h
index c821efc0f60eb28dfb395f5e69a35e8cd7d305c5..65fe7dbe027eb2e93eb02c7ddfed9898ea9bcee2 100644 (file)
--- a/plat/rockchip/rk3399/drivers/pmu/pmu.h
+++ b/plat/rockchip/rk3399/drivers/pmu/pmu.h
@@ -819,6 +819,7 @@ enum pmu_core_pwr_st {
 
 #define AP_PWROFF              0x0a
 
+#define GPIO0A0_SMT_ENABLE     BITS_WITH_WMASK(1, 3, 0)
 #define GPIO1A6_IOMUX          BITS_WITH_WMASK(0, 3, 12)
 
 #define TSADC_INT_PIN          38
@@ -876,6 +877,7 @@ enum pmu_core_pwr_st {
 #define        GRF_SOC_CON4            0x0e210
 #define GRF_GPIO4C_IOMUX       0x0e028
 
+#define PMUGRF_GPIO0A_SMT      0x0120
 #define PMUGRF_SOC_CON0                0x0180
 
 #define CCI_FORCE_WAKEUP       WMSK_BIT(8)