[2/3] clk: add ICST307 driver

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 4864407..32e745e 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -34,4 +34,9 @@  config COMMON_CLK_DEBUG
 	  clk_flags, clk_prepare_count, clk_enable_count &
 	  clk_notifier_count.
 
+config CLK_ICST
+	bool "ICST307 VCO clock driver"
+	depends on COMMON_CLK
+	depends on ICST
+
 endmenu
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index b9a5158..a7a7cf8 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -5,3 +5,4 @@  obj-$(CONFIG_COMMON_CLK)	+= clk.o clk-fixed-rate.o clk-gate.o \
 # SoCs specific
 obj-$(CONFIG_ARCH_MXS)		+= mxs/
 obj-$(CONFIG_PLAT_SPEAR)	+= spear/
+obj-$(CONFIG_CLK_ICST)		+= clk-icst.o
diff --git a/drivers/clk/clk-icst.c b/drivers/clk/clk-icst.c
new file mode 100644
index 0000000..ba003de
--- /dev/null
+++ b/drivers/clk/clk-icst.c
@@ -0,0 +1,99 @@ 
+/*
+ * Driver for the ICST307 VCO clock found in the ARM Reference designs.
+ * We wrap the custom interface from <asm/hardware/icst.h> into the generic
+ * clock framework.
+ *
+ * TODO: when all ARM reference designs are migrated to generic clocks, the
+ * ICST clock code from the ARM tree should probably be merged into this
+ * file.
+ */
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/err.h>
+#include <linux/clk-provider.h>
+
+#include "clk-icst.h"
+
+/**
+ * struct clk_icst - ICST VCO clock wrapper
+ * @hw: corresponding clock hardware entry
+ * @params: parameters for this ICST instance
+ * @rate: current rate
+ * @setvco: function to commit ICST settings to hardware
+ */
+struct clk_icst {
+	struct clk_hw hw;
+	const struct icst_params *params;
+	unsigned long rate;
+	struct icst_vco (*getvco)(void);
+	void (*setvco)(struct icst_vco);
+};
+
+#define to_icst(_hw) container_of(_hw, struct clk_icst, hw)
+
+static unsigned long icst_recalc_rate(struct clk_hw *hw,
+				      unsigned long parent_rate)
+{
+	struct clk_icst *icst = to_icst(hw);
+	struct icst_vco vco;
+
+	vco = icst->getvco();
+	icst->rate = icst_hz(icst->params, vco);
+	return icst->rate;
+}
+
+static long icst_round_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long *prate)
+{
+	struct clk_icst *icst = to_icst(hw);
+	struct icst_vco vco;
+
+	vco = icst_hz_to_vco(icst->params, rate);
+	return icst_hz(icst->params, vco);
+}
+
+static int icst_set_rate(struct clk_hw *hw, unsigned long rate,
+			 unsigned long parent_rate)
+{
+	struct clk_icst *icst = to_icst(hw);
+	struct icst_vco vco;
+
+	vco = icst_hz_to_vco(icst->params, rate);
+	icst->rate = icst_hz(icst->params, vco);
+	icst->setvco(vco);
+	return 0;
+}
+
+static const struct clk_ops icst_ops = {
+	.recalc_rate = icst_recalc_rate,
+	.round_rate = icst_round_rate,
+	.set_rate = icst_set_rate,
+};
+
+struct clk * __init icst_clk_init(struct device *dev, const struct clk_icst_desc *desc)
+{
+	struct clk *clk;
+	struct clk_icst *icst;
+	struct clk_init_data init;
+
+	icst = kzalloc(sizeof(struct clk_icst), GFP_KERNEL);
+	if (!icst) {
+		pr_err("could not allocate ICST clock!\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	init.name = "icst";
+	init.ops = &icst_ops;
+	init.flags = CLK_IS_ROOT;
+	init.parent_names = NULL;
+	init.num_parents = 0;
+	icst->hw.init = &init;
+	icst->params = desc->params;
+	icst->getvco = desc->getvco;
+	icst->setvco = desc->setvco;
+
+	clk = clk_register(dev, &icst->hw);
+	if (IS_ERR(clk))
+		kfree(icst);
+
+	return clk;
+}
diff --git a/drivers/clk/clk-icst.h b/drivers/clk/clk-icst.h
new file mode 100644
index 0000000..1deaa86
--- /dev/null
+++ b/drivers/clk/clk-icst.h
@@ -0,0 +1,10 @@ 
+#include <asm/hardware/icst.h>
+
+struct clk_icst_desc {
+	const struct icst_params *params;
+	struct icst_vco (*getvco)(void);
+	void (*setvco)(struct icst_vco);
+};
+
+struct clk *icst_clk_init(struct device *dev,
+			  const struct clk_icst_desc *desc);