ARM: tegra: emc: add eack_disable functionality

Bug 946110

Signed-off-by: Ray Poudrier <rapoudrier@nvidia.com>

Change-Id: I0d4c716c4ab7a60011018d6c13be4265cc9f7290
Reviewed-on: http://git-master/r/87061
(cherry picked from commit a7dad880dcea36fcb8223cf0b34cc1091d725a9f)
Reviewed-on: http://git-master/r/102360
Reviewed-by: Raymond Poudrier <rapoudrier@nvidia.com>
Tested-by: Raymond Poudrier <rapoudrier@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>

2 files changed, 50 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/tegra3_emc.c b/arch/arm/mach-tegra/tegra3_emc.c
index 0725980bfa40..83136e3c08d1 100644
--- a/arch/arm/mach-tegra/tegra3_emc.c
+++ b/arch/arm/mach-tegra/tegra3_emc.c
@@ -350,6 +350,12 @@ static inline void disable_early_ack(u32 mc_override)
 	override_val |= mc_override & MC_EMEM_ARB_OVERRIDE_EACK_MASK;
 }
 
+static inline void enable_early_ack(u32 mc_override)
+{
+	mc_writel((mc_override | MC_EMEM_ARB_OVERRIDE_EACK_MASK),
+			MC_EMEM_ARB_OVERRIDE);
+}
+
 static inline bool dqs_preset(const struct tegra_emc_table *next_timing,
 			      const struct tegra_emc_table *last_timing)
 {
@@ -1163,6 +1169,24 @@ int tegra_emc_set_over_temp_state(unsigned long state)
 	return 0;
 }
 
+int tegra_emc_set_eack_state(unsigned long state)
+{
+	unsigned long flags;
+	u32 mc_override;
+
+	spin_lock_irqsave(&emc_access_lock, flags);
+
+	mc_override = mc_readl(MC_EMEM_ARB_OVERRIDE);
+
+	if (state)
+		enable_early_ack(mc_override);
+	else
+		disable_early_ack(mc_override);
+
+	spin_unlock_irqrestore(&emc_access_lock, flags);
+	return 0;
+}
+
 #ifdef CONFIG_DEBUG_FS
 
 static struct dentry *emc_debugfs_root;
@@ -1222,6 +1246,27 @@ static int over_temp_state_set(void *data, u64 val)
 DEFINE_SIMPLE_ATTRIBUTE(over_temp_state_fops, over_temp_state_get,
 			over_temp_state_set, "%llu\n");
 
+static int eack_state_get(void *data, u64 *val)
+{
+	unsigned long flags;
+	u32 mc_override;
+
+	spin_lock_irqsave(&emc_access_lock, flags);
+	mc_override = mc_readl(MC_EMEM_ARB_OVERRIDE);
+	spin_unlock_irqrestore(&emc_access_lock, flags);
+
+	*val = (mc_override & MC_EMEM_ARB_OVERRIDE_EACK_MASK);
+	return 0;
+}
+
+static int eack_state_set(void *data, u64 val)
+{
+	tegra_emc_set_eack_state(val);
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(eack_state_fops, eack_state_get,
+			eack_state_set, "%llu\n");
+
 static int __init tegra_emc_debug_init(void)
 {
 	if (!tegra_emc_table)
@@ -1243,6 +1288,10 @@ static int __init tegra_emc_debug_init(void)
 				 emc_debugfs_root, NULL, &over_temp_state_fops))
 		goto err_out;
 
+	if (!debugfs_create_file(
+		"eack_state", S_IRUGO | S_IWUGO, emc_debugfs_root, NULL, &eack_state_fops))
+		goto err_out;
+
 	return 0;
 
 err_out:
diff --git a/arch/arm/mach-tegra/tegra3_emc.h b/arch/arm/mach-tegra/tegra3_emc.h
index cfde92c1355a..03bde19c4a7b 100644
--- a/arch/arm/mach-tegra/tegra3_emc.h
+++ b/arch/arm/mach-tegra/tegra3_emc.h
@@ -59,6 +59,7 @@ void tegra_emc_dram_type_init(struct clk *c);
 int tegra_emc_get_dram_type(void);
 int tegra_emc_get_dram_temperature(void);
 int tegra_emc_set_over_temp_state(unsigned long state);
+int tegra_emc_set_eack_state(unsigned long state);
 
 #ifdef CONFIG_PM_SLEEP
 void tegra_mc_timing_restore(void);