Tegra210: wait for 512 timer ticks before retention entry
This patch programs the CPUECTLR_EL1 and L2ECTLR_EL1 registers,
so that the core waits for 512 generic timer CNTVALUEB ticks before
entering retention state, after executing a WFI instruction.
This functionality is configurable and can be enabled for platforms
by setting the newly defined 'ENABLE_L2_DYNAMIC_RETENTION' and
'ENABLE_CPU_DYNAMIC_RETENTION' flag.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/nvidia/tegra/common/aarch64/tegra_helpers.S b/plat/nvidia/tegra/common/aarch64/tegra_helpers.S
index 2979b32..d9f287c 100644
--- a/plat/nvidia/tegra/common/aarch64/tegra_helpers.S
+++ b/plat/nvidia/tegra/common/aarch64/tegra_helpers.S
@@ -57,6 +57,28 @@
*/
.macro cpu_init_common
+#if ENABLE_L2_DYNAMIC_RETENTION
+ /* ---------------------------
+ * Enable processor retention
+ * ---------------------------
+ */
+ mrs x0, L2ECTLR_EL1
+ mov x1, #RETENTION_ENTRY_TICKS_512 << L2ECTLR_RET_CTRL_SHIFT
+ bic x0, x0, #L2ECTLR_RET_CTRL_MASK
+ orr x0, x0, x1
+ msr L2ECTLR_EL1, x0
+ isb
+#endif
+
+#if ENABLE_CPU_DYNAMIC_RETENTION
+ mrs x0, CPUECTLR_EL1
+ mov x1, #RETENTION_ENTRY_TICKS_512 << CPUECTLR_CPU_RET_CTRL_SHIFT
+ bic x0, x0, #CPUECTLR_CPU_RET_CTRL_MASK
+ orr x0, x0, x1
+ msr CPUECTLR_EL1, x0
+ isb
+#endif
+
#if ENABLE_NS_L2_CPUECTRL_RW_ACCESS
/* -------------------------------------------------------
* Enable L2 and CPU ECTLR RW access from non-secure world
diff --git a/plat/nvidia/tegra/soc/t210/platform_t210.mk b/plat/nvidia/tegra/soc/t210/platform_t210.mk
index ca7718c..5001629 100644
--- a/plat/nvidia/tegra/soc/t210/platform_t210.mk
+++ b/plat/nvidia/tegra/soc/t210/platform_t210.mk
@@ -40,6 +40,12 @@
ENABLE_NS_L2_CPUECTRL_RW_ACCESS := 1
$(eval $(call add_define,ENABLE_NS_L2_CPUECTRL_RW_ACCESS))
+ENABLE_L2_DYNAMIC_RETENTION := 1
+$(eval $(call add_define,ENABLE_L2_DYNAMIC_RETENTION))
+
+ENABLE_CPU_DYNAMIC_RETENTION := 1
+$(eval $(call add_define,ENABLE_CPU_DYNAMIC_RETENTION))
+
PLATFORM_CLUSTER_COUNT := 2
$(eval $(call add_define,PLATFORM_CLUSTER_COUNT))