[PATCH] clk: Add device tree binding to clk-fixed-factor

[Christian Ruppert]

This patch adds a device tree binding for the simple fixed factor clock
divider/multiplier of the common clock tree binding.

Signed-off-by: Christian Ruppert <christian.ruppert at abilis.com>
---
 .../bindings/clock/fixed-factor-clkdiv.txt         |   24 +++++++++++++++
 drivers/clk/clk-fixed-factor.c                     |   32 ++++++++++++++++++++
 include/linux/clk-provider.h                       |    1 +
 3 files changed, 57 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/fixed-factor-clkdiv.txt

diff --git a/Documentation/devicetree/bindings/clock/fixed-factor-clkdiv.txt b/Documentation/devicetree/bindings/clock/fixed-factor-clkdiv.txt
new file mode 100644
index 0000000..352bac4
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/fixed-factor-clkdiv.txt
@@ -0,0 +1,24 @@
+Device Tree Clock bindings for plat-tb10x
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be "fixed-factor-clkdiv"
+- #clock-cells: from common clock binding; shall be set to 0
+- clocks: shall be the input parent clock phandle for the clock.
+- clock-mult: defines the multiplication factor of the output clock frequency
+  wrt. the input clock frequency.
+- clock-div: defines the division factor of the output clock frequency wrt.
+  the input clock frequency.
+
+Example:
+cpu_clk: clkdiv_cpu {	/* CPU clock derived from pll0. 1/2 of pll frequency */
+	compatible = "fixed-factor-clkdiv";
+	#clock-cells = <0>;
+	clocks = <&pll0>;
+	clock-mult = <1>;
+	clock-div = <2>;
+	clock-output-names = "cpu_clk";
+};
diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index 1ef271e..85e45f1 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -11,6 +11,7 @@
 #include <linux/clk-provider.h>
 #include <linux/slab.h>
 #include <linux/err.h>
+#include <linux/of.h>
 
 /*
  * DOC: basic fixed multiplier and divider clock that cannot gate
@@ -96,3 +97,34 @@ struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
 
 	return clk;
 }
+
+#ifdef CONFIG_OF
+/**
+ * of_fixed_factor_clkdiv_setup() - Set up simple fixed factor clock divider
+ */
+void of_fixed_factor_clkdiv_setup(struct device_node *node)
+{
+	struct clk *clk;
+	const char *clk_name = node->name;
+	const char *parent_name;
+	u32 mult, div;
+
+	if (of_property_read_u32(node, "clock-mult", &mult))
+		return;
+
+	if (of_property_read_u32(node, "clock-div", &div))
+		return;
+
+	parent_name = of_clk_get_parent_name(node, 0);
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
+					mult, div);
+	if (!IS_ERR(clk))
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+}
+EXPORT_SYMBOL_GPL(of_fixed_factor_clkdiv_setup);
+CLK_OF_DECLARE(fixed_clkdiv, "fixed-factor-clkdiv",
+		of_fixed_factor_clkdiv_setup);
+#endif
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 7f197d7..d4937cf 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -184,6 +184,7 @@ struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
 		unsigned long fixed_rate);
 
 void of_fixed_clk_setup(struct device_node *np);
+void of_fixed_factor_clkdiv_setup(struct device_node *node);
 
 /**
  * struct clk_gate - gating clock
-- 
1.7.1