[PATCH] clk: add clk_possible_parents debugfs file

From: Peter De Schrijver
Date: Tue Mar 21 2017 - 09:21:53 EST


For validation purposes, it's often useful to be able to retrieve the list
of possible parents in userspace. Add a debugfs file for every clock which
has more than 1 possible parent.

Signed-off-by: Peter De Schrijver <pdeschrijver@xxxxxxxxxx>
Reviewed-by: Jon Mayo <jmayo@xxxxxxxxxx>
---
drivers/clk/clk.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index f5f2bcd..2fa2fb8 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2128,6 +2128,34 @@ static int clk_dump_open(struct inode *inode, struct file *file)
.release = single_release,
};

+static int possible_parents_dump(struct seq_file *s, void *data)
+{
+ struct clk_core *core;
+ int i;
+
+ core = (struct clk_core *)s->private;
+
+ for (i = 0; i < core->num_parents - 1; i++)
+ seq_printf(s, "%s ", core->parent_names[i]);
+
+ seq_printf(s, "%s\n", core->parent_names[i]);
+
+ return 0;
+}
+
+static int possible_parents_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, possible_parents_dump, inode->i_private);
+}
+
+
+static const struct file_operations possible_parents_fops = {
+ .open = possible_parents_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
{
struct dentry *d;
@@ -2179,6 +2207,13 @@ static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
if (!d)
goto err_out;

+ if (core->num_parents > 1) {
+ d = debugfs_create_file("clk_possible_parents", S_IRUGO,
+ core->dentry, core, &possible_parents_fops);
+ if (!d)
+ goto err_out;
+ }
+
if (core->ops->debug_init) {
ret = core->ops->debug_init(core->hw, core->dentry);
if (ret)
--
1.9.1