clk: Add clk gate support

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 82 insertions, 1 deletions

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 39a75a4e4a..3cc7163829 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -1,2 +1,3 @@
-obj-$(CONFIG_COMMON_CLK)	+= clk.o clk-fixed.o clk-divider.o clk-fixed-factor.o clk-mux.o
+obj-$(CONFIG_COMMON_CLK)	+= clk.o clk-fixed.o clk-divider.o clk-fixed-factor.o \
+				clk-mux.o clk-gate.o
 obj-$(CONFIG_CLKDEV_LOOKUP)	+= clkdev.o
diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c
new file mode 100644
index 0000000000..cf1bb1af62
--- /dev/null
+++ b/drivers/clk/clk-gate.c
@@ -0,0 +1,78 @@
+/*
+ * clk-gate.c - generic barebox clock support. Based on Linux clk support
+ *
+ * Copyright (c) 2012 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <common.h>
+#include <io.h>
+#include <malloc.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+struct clk_gate {
+	struct clk clk;
+	void __iomem *reg;
+	int shift;
+	const char *parent;
+};
+
+static int clk_gate_enable(struct clk *clk)
+{
+	struct clk_gate *g = container_of(clk, struct clk_gate, clk);
+	u32 val;
+
+	val = readl(g->reg);
+	val |= 1 << g->shift;
+	writel(val, g->reg);
+
+	return 0;
+}
+
+static void clk_gate_disable(struct clk *clk)
+{
+	struct clk_gate *g = container_of(clk, struct clk_gate, clk);
+	u32 val;
+
+	val = readl(g->reg);
+	val &= ~(1 << g->shift);
+	writel(val, g->reg);
+}
+
+struct clk_ops clk_gate_ops = {
+	.enable = clk_gate_enable,
+	.disable = clk_gate_disable,
+};
+
+struct clk *clk_gate(const char *name, const char *parent, void __iomem *reg,
+		u8 shift)
+{
+	struct clk_gate *g = xzalloc(sizeof(*g));
+	int ret;
+
+	g->parent = parent;
+	g->reg = reg;
+	g->shift = shift;
+	g->clk.ops = &clk_gate_ops;
+	g->clk.name = name;
+	g->clk.parent_names = &g->parent;
+	g->clk.num_parents = 1;
+
+	ret = clk_register(&g->clk);
+	if (ret) {
+		free(g);
+		return ERR_PTR(ret);
+	}
+
+	return &g->clk;
+}
diff --git a/include/linux/clk.h b/include/linux/clk.h
index e9031dd17a..00588bff05 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -188,6 +188,8 @@ struct clk *clk_fixed_factor(const char *name,
 		const char *parent, unsigned int mult, unsigned int div);
 struct clk *clk_mux(const char *name, void __iomem *reg,
 		u8 shift, u8 width, const char **parents, u8 num_parents);
+struct clk *clk_gate(const char *name, const char *parent, void __iomem *reg,
+		u8 shift);
 
 int clk_register(struct clk *clk);