From 2abd2a45ab2fc6df6cf8602a9be1f2633edbee43 Mon Sep 17 00:00:00 2001
From: Mikko Perttunen <mperttunen@nvidia.com>
Date: Thu, 12 Mar 2015 15:48:06 +0100
Subject: [PATCH] memory: tegra: Add debugfs entry for getting and setting the
 EMC rate

Will be very useful when tuning memory scaling.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/memory/tegra/tegra124-emc.c | 36 +++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
index 7f73fd31e201..26010adce667 100644
--- a/drivers/memory/tegra/tegra124-emc.c
+++ b/drivers/memory/tegra/tegra124-emc.c
@@ -18,6 +18,7 @@
 #include <linux/clk-provider.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/of_address.h>
 #include <linux/of_platform.h>
@@ -1013,6 +1014,38 @@ static struct device_node *tegra_emc_find_node_by_ram_code(
 	return NULL;
 }
 
+/* Debugfs entry */
+
+static int emc_debug_rate_get(void *data, u64 *rate)
+{
+	struct clk *c = data;
+
+	*rate = clk_get_rate(c);
+
+	return 0;
+}
+
+static int emc_debug_rate_set(void *data, u64 rate)
+{
+	struct clk *c = data;
+
+	return clk_set_rate(c, rate);
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(emc_debug_rate_fops, emc_debug_rate_get,
+			emc_debug_rate_set, "%lld\n");
+
+static void emc_debugfs_init(void)
+{
+	struct dentry *d;
+
+	d = debugfs_create_file("emc_rate", S_IRUGO | S_IWUSR, NULL,
+				clk_get_sys("tegra-clk-debug", "emc"),
+				&emc_debug_rate_fops);
+	if (!d)
+		pr_warn("failed to create debugfs entries\n");
+}
+
 static int tegra_emc_probe(struct platform_device *pdev)
 {
 	struct tegra_emc *tegra;
@@ -1082,6 +1115,9 @@ static int tegra_emc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, tegra);
 
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		emc_debugfs_init();
+
 	return 0;
 };
 
-- 
2.39.5