[PATCH v4 3/7] interconnect: Add debugfs support

[Georgi Djakov]

Add a functionality to provide information about the current constraints
per each node and provider.

Signed-off-by: Georgi Djakov <georgi.dja...@linaro.org>
---
 drivers/interconnect/core.c | 70 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 6306e258b9b9..a06f752a6aaa 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -6,6 +6,7 @@
  * Author: Georgi Djakov <georgi.dja...@linaro.org>
  */
 
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/idr.h>
 #include <linux/init.h>
@@ -15,11 +16,13 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/uaccess.h>
 
 static DEFINE_IDR(icc_idr);
 static LIST_HEAD(icc_provider_list);
 static DEFINE_MUTEX(icc_provider_list_mutex);
 static DEFINE_MUTEX(icc_path_mutex);
+static struct dentry *icc_debugfs_dir;
 
 /**
  * struct icc_req - constraints that are attached to each node
@@ -46,6 +49,73 @@ struct icc_path {
        struct icc_req reqs[0];
 };
 
+#ifdef CONFIG_DEBUG_FS
+
+static void icc_summary_show_one(struct seq_file *s, struct icc_node *n)
+{
+       if (!n)
+               return;
+
+       seq_printf(s, "%-30s %12d %12d\n",
+                  n->name, n->avg_bw, n->peak_bw);
+}
+
+static int icc_summary_show(struct seq_file *s, void *data)
+{
+       struct icc_provider *provider;
+
+       seq_puts(s, " node                                   avg         
peak\n");
+       seq_puts(s, 
"--------------------------------------------------------\n");
+
+       mutex_lock(&icc_provider_list_mutex);
+
+       list_for_each_entry(provider, &icc_provider_list, provider_list) {
+               struct icc_node *n;
+
+               mutex_lock(&provider->lock);
+               list_for_each_entry(n, &provider->nodes, node_list) {
+                       icc_summary_show_one(s, n);
+               }
+               mutex_unlock(&provider->lock);
+       }
+
+       mutex_unlock(&icc_provider_list_mutex);
+
+       return 0;
+}
+
+static int icc_summary_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, icc_summary_show, inode->i_private);
+}
+
+static const struct file_operations icc_summary_fops = {
+       .open           = icc_summary_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+static int __init icc_debugfs_init(void)
+{
+       struct dentry *file;
+
+       icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
+       if (!icc_debugfs_dir) {
+               pr_err("interconnect: error creating debugfs directory\n");
+               return -ENODEV;
+       }
+
+       file = debugfs_create_file("interconnect_summary", 0444,
+                                  icc_debugfs_dir, NULL, &icc_summary_fops);
+       if (!file)
+               return -ENODEV;
+
+       return 0;
+}
+late_initcall(icc_debugfs_init);
+#endif
+
 static struct icc_node *node_find(const int id)
 {
        struct icc_node *node;