[PATCH v2 RESEND] clk: support hardware-specific debugfs entries

[Alex Elder]

Add a new clk_ops->debug_init method to allow a clock hardware
driver to populate the clock's debugfs directory with entries
beyond those common for every clock.

Signed-off-by: Alex Elder <elder at linaro.org>
---
v2: - Define debug_init unconditionally (suggested by Gerhard Sittig).

 drivers/clk/clk.c            |    4 ++++
 include/linux/clk-provider.h |    8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index e3e0327..8769b01 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -277,6 +277,10 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry)
 	if (!d)
 		goto err_out;
 
+	if (clk->ops->debug_init)
+		if (clk->ops->debug_init(clk->hw, clk->dentry))
+			goto err_out;
+
 	ret = 0;
 	goto out;
 
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 5429f5d..b91674d 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -32,6 +32,7 @@
 #define CLK_GET_ACCURACY_NOCACHE BIT(8) /* do not use the cached clk accuracy */
 
 struct clk_hw;
+struct dentry;
 
 /**
  * struct clk_ops -  Callback operations for hardware clocks; these are to
@@ -116,6 +117,12 @@ struct clk_hw;
  *		set then clock accuracy will be initialized to parent accuracy
  *		or 0 (perfect clock) if clock has no parent.
  *
+ * @debug_init:	Set up type-specific debugfs entries for this clock.  This
+ *		is called once, after the debugfs directory entry for this
+ *		clock has been created.  The dentry pointer representing that
+ *		directory is provided as an argument.  Called with
+ *		prepare_lock held.  Returns 0 on success, -EERROR otherwise.
+ *
  * The clk_enable/clk_disable and clk_prepare/clk_unprepare pairs allow
  * implementations to split any work between atomic (enable) and sleepable
  * (prepare) contexts.  If enabling a clock requires code that might sleep,
@@ -150,6 +157,7 @@ struct clk_ops {
 	unsigned long	(*recalc_accuracy)(struct clk_hw *hw,
 					   unsigned long parent_accuracy);
 	void		(*init)(struct clk_hw *hw);
+	int		(*debug_init)(struct clk_hw *hw, struct dentry *dentry);
 };
 
 /**
-- 
1.7.9.5