clk: add accuracy support for fixed clock

This patch adds support for accuracy retrieval on fixed clocks.
It also adds a new dt property called 'clock-accuracy' to define the clock
accuracy.

This can be usefull for oscillator (RC, crystal, ...) definitions which are
always given an accuracy characteristic.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

1 files changed, 37 insertions, 6 deletions

diff --git a/drivers/clk/clk-fixed-rate.c b/drivers/clk/clk-fixed-rate.c
index 1ed591a..0fc56ab 100644
--- a/drivers/clk/clk-fixed-rate.c
+++ b/drivers/clk/clk-fixed-rate.c
@@ -34,22 +34,31 @@ static unsigned long clk_fixed_rate_recalc_rate(struct clk_hw *hw,
 	return to_clk_fixed_rate(hw)->fixed_rate;
 }
 
+static unsigned long clk_fixed_rate_recalc_accuracy(struct clk_hw *hw,
+		unsigned long parent_accuracy)
+{
+	return to_clk_fixed_rate(hw)->fixed_accuracy;
+}
+
 const struct clk_ops clk_fixed_rate_ops = {
 	.recalc_rate = clk_fixed_rate_recalc_rate,
+	.recalc_accuracy = clk_fixed_rate_recalc_accuracy,
 };
 EXPORT_SYMBOL_GPL(clk_fixed_rate_ops);
 
 /**
- * clk_register_fixed_rate - register fixed-rate clock with the clock framework
+ * clk_register_fixed_rate_with_accuracy - register fixed-rate clock with the
+ *					   clock framework
  * @dev: device that is registering this clock
  * @name: name of this clock
  * @parent_name: name of clock's parent
  * @flags: framework-specific flags
  * @fixed_rate: non-adjustable clock rate
+ * @fixed_accuracy: non-adjustable clock rate
  */
-struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
-		const char *parent_name, unsigned long flags,
-		unsigned long fixed_rate)
+struct clk *clk_register_fixed_rate_with_accuracy(struct device *dev,
+		const char *name, const char *parent_name, unsigned long flags,
+		unsigned long fixed_rate, unsigned long fixed_accuracy)
 {
 	struct clk_fixed_rate *fixed;
 	struct clk *clk;
@@ -70,16 +79,33 @@ struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
 
 	/* struct clk_fixed_rate assignments */
 	fixed->fixed_rate = fixed_rate;
+	fixed->fixed_accuracy = fixed_accuracy;
 	fixed->hw.init = &init;
 
 	/* register the clock */
 	clk = clk_register(dev, &fixed->hw);
-
 	if (IS_ERR(clk))
 		kfree(fixed);
 
 	return clk;
 }
+EXPORT_SYMBOL_GPL(clk_register_fixed_rate_with_accuracy);
+
+/**
+ * clk_register_fixed_rate - register fixed-rate clock with the clock framework
+ * @dev: device that is registering this clock
+ * @name: name of this clock
+ * @parent_name: name of clock's parent
+ * @flags: framework-specific flags
+ * @fixed_rate: non-adjustable clock rate
+ */
+struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
+		const char *parent_name, unsigned long flags,
+		unsigned long fixed_rate)
+{
+	return clk_register_fixed_rate_with_accuracy(dev, name, parent_name,
+						     flags, fixed_rate, 0);
+}
 EXPORT_SYMBOL_GPL(clk_register_fixed_rate);
 
 #ifdef CONFIG_OF
@@ -91,13 +117,18 @@ void of_fixed_clk_setup(struct device_node *node)
 	struct clk *clk;
 	const char *clk_name = node->name;
 	u32 rate;
+	u32 accuracy = 0;
 
 	if (of_property_read_u32(node, "clock-frequency", &rate))
 		return;
 
+	of_property_read_u32(node, "clock-accuracy", &accuracy);
+
 	of_property_read_string(node, "clock-output-names", &clk_name);
 
-	clk = clk_register_fixed_rate(NULL, clk_name, NULL, CLK_IS_ROOT, rate);
+	clk = clk_register_fixed_rate_with_accuracy(NULL, clk_name, NULL,
+						    CLK_IS_ROOT, rate,
+						    accuracy);
 	if (!IS_ERR(clk))
 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
 }