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>

diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
index 7f73fd31e20160411ece8d3bf54f3ed6c03cb038..26010adce667327bc96219d5a2223668df24e271 100644 (file)
--- 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;
 };