[U-Boot] [PATCH 08/11] Exynos542x: add L2 control register configuration

[Akshay Saraswat]

This patch does 3 things:
1. Enables ECC by setting 21st bit of L2CTLR.
2. Restore data and tag RAM latencies to 3 cycles because iROM sets
   0x3000400 L2CTLR value during switching.
3. Disable clean/evict push to external by setting 3rd bit of L2ACTLR.
   We need to restore this here due to switching.

Signed-off-by: Abhilash Kesavan <a.kesavan at samsung.com>
Signed-off-by: Akshay Saraswat <akshay.s at samsung.com>
---
 arch/arm/cpu/armv7/exynos/lowlevel_init.c | 53 +++++++++++++++++++++++--------
 arch/arm/cpu/armv7/exynos/soc.c           |  7 ++++
 2 files changed, 46 insertions(+), 14 deletions(-)

diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
index 688972b..57b4c66 100644
--- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c
+++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c
@@ -67,24 +67,40 @@ static void enable_smp(void)
 }
 
 /*
+ * Enable ECC by setting L2CTLR[21].
+ * Set L2CTLR[7] to make tag ram latency 3 cycles and
+ * set L2CTLR[1] to make data ram latency 3 cycles.
+ * We need to make RAM latency of 3 cycles here because cores
+ * power ON and OFF while switching. And everytime a core powers
+ * ON, iROM provides it a default L2CTLR value 0x400 which stands
+ * for TAG RAM setup of 1 cycle. Hence, we face a need of
+ * restoring data and tag latency values.
+ */
+static void configure_l2_ctlr(void)
+{
+	uint32_t val;
+
+	mrc_l2_ctlr(val);
+	val |= (1 << 21);
+	val |= (1 << 7);
+	val |= (1 << 1);
+	mcr_l2_ctlr(val);
+}
+
+/*
  * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been
  * stalled for 1024 cycles to verify that its hazard condition still exists.
+ * Disable clean/evict push to external by setting L2ACTLR[3].
  */
-static void configure_l2actlr(void)
+static void configure_l2_actlr(void)
 {
 	uint32_t val;
 
-	/* Read MIDR for Primary Part Number*/
-	mrc_midr(val);
-	val = (val >> 4);
-	val &= 0xf;
-
-	/* L2ACTLR[7]: Enable hazard detect timeout for A15 */
-	if (val == 0xf) {
-		mrc_l2_aux_ctlr(val);
-		val |= (1 << 7);
-		mcr_l2_aux_ctlr(val);
-	}
+	mrc_l2_aux_ctlr(val);
+	val |= (1 << 27);
+	val |= (1 << 7);
+	val |= (1 << 3);
+	mcr_l2_aux_ctlr(val);
 }
 
 /*
@@ -121,7 +137,16 @@ static void low_power_start(void)
 
 	/* Set the CPU to SVC32 mode */
 	svc32_mode_en();
-	configure_l2actlr();
+
+	/* Read MIDR for Primary Part Number*/
+	mrc_midr(val);
+	val = (val >> 4);
+	val &= 0xf;
+
+	if (val == 0xf) {
+		configure_l2_ctlr();
+		configure_l2_actlr();
+	}
 
 	/* Invalidate L1 & TLB */
 	val = 0x0;
@@ -174,7 +199,7 @@ static void power_down_core(void)
 static void secondary_cores_configure(void)
 {
 	/* Setup L2 cache */
-	configure_l2actlr();
+	configure_l2_ctlr();
 
 	/* Clear secondary boot iRAM base */
 	writel(0x0, (CONFIG_EXYNOS_RELOCATE_CODE_BASE + 0x1C));
diff --git a/arch/arm/cpu/armv7/exynos/soc.c b/arch/arm/cpu/armv7/exynos/soc.c
index 7268b9b..ea201e7 100644
--- a/arch/arm/cpu/armv7/exynos/soc.c
+++ b/arch/arm/cpu/armv7/exynos/soc.c
@@ -10,8 +10,10 @@
 #include <asm/system.h>
 
 enum l2_cache_params {
+#ifndef CONFIG_EXYNOS5420
 	CACHE_TAG_RAM_SETUP = (1 << 9),
 	CACHE_DATA_RAM_SETUP = (1 << 5),
+#endif
 	CACHE_TAG_RAM_LATENCY = (2 << 6),
 	CACHE_DATA_RAM_LATENCY = (2 << 0)
 };
@@ -39,10 +41,15 @@ static void exynos5_set_l2cache_params(void)
 
 	asm volatile("mrc p15, 1, %0, c9, c0, 2\n" : "=r"(val));
 
+#ifndef CONFIG_EXYNOS5420
 	val |= CACHE_TAG_RAM_SETUP |
 		CACHE_DATA_RAM_SETUP |
 		CACHE_TAG_RAM_LATENCY |
 		CACHE_DATA_RAM_LATENCY;
+#else
+	val |= CACHE_TAG_RAM_LATENCY |
+		CACHE_DATA_RAM_LATENCY;
+#endif
 
 	asm volatile("mcr p15, 1, %0, c9, c0, 2\n" : : "r"(val));
 
-- 
1.9.1