Tegra210: se: disable SMMU before suspending SE block

This patch disables SMMU hardware before suspending the SE
block, for the context save operation to complete. The NS
word will re-enable SMMU when we exit System Suspend.

Change-Id: I4d5cd982ea6780db5c38b124550d847e3928c60d
Signed-off-by: Samuel Payne <spayne@nvidia.com>

plat/nvidia/tegra/include/t210/tegra_def.h

@@ -153,6 +153,10 @@
 #define MC_VIDEO_PROTECT_BASE_LO	U(0x648)
 #define MC_VIDEO_PROTECT_SIZE_MB	U(0x64c)
 
+/* SMMU configuration registers*/
+#define MC_SMMU_PPCS_ASID_0		0x270UL
+#define  PPCS_SMMU_ENABLE		(0x1U << 31)
+
 /*******************************************************************************
  * Tegra SE constants
  ******************************************************************************/

plat/nvidia/tegra/soc/t210/drivers/se/security_engine.c

@@ -401,6 +401,14 @@ void tegra_se_init(void)
 int32_t tegra_se_suspend(void)
 {
 	int32_t ret = 0;
+	uint32_t val = 0;
+
+	/* SE does not use SMMU in EL3, disable SMMU.
+	 * This will be re-enabled by kernel on resume */
+	val = mmio_read_32(TEGRA_MC_BASE + MC_SMMU_PPCS_ASID_0);
+	val &= ~PPCS_SMMU_ENABLE;
+	mmio_write_32(TEGRA_MC_BASE + MC_SMMU_PPCS_ASID_0, val);
+
 
 	/* Atomic context save se2 and pka1 */
 	INFO("%s: SE2/PKA1 atomic context save\n", __func__);