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>
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 16d182c..5429f5d 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -204,6 +204,7 @@
 struct clk_fixed_rate {
 	struct		clk_hw hw;
 	unsigned long	fixed_rate;
+	unsigned long	fixed_accuracy;
 	u8		flags;
 };
 
@@ -211,6 +212,9 @@
 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);
 
 void of_fixed_clk_setup(struct device_node *np);