[PATCH 02/18] CLK: Add support for composite clock from Linux kernel.

[Andrey Panov]

Arch Kconfig should select CLK_NEED_COMPOSITE to have this support
compiled in.

Signed-off-by: Andrey Panov <rockford at yandex.ru>
---
 drivers/clk/Kconfig         |   3 +
 drivers/clk/Makefile        |   1 +
 drivers/clk/clk-composite.c | 146 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/clk.h         |   6 ++
 4 files changed, 156 insertions(+)
 create mode 100644 drivers/clk/clk-composite.c

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 1cf0ccb..6db1f33 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -8,6 +8,9 @@ config COMMON_CLK
 	select HAVE_CLK
 	bool
 
+config CLK_NEED_COMPOSITE
+	bool
+
 config COMMON_CLK_OF_PROVIDER
 	bool
 	help
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index fa707dd..bdd93f5 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -1,6 +1,7 @@
 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
+obj-$(CONFIG_CLK_NEED_COMPOSITE)	+= clk-composite.o
 
 obj-$(CONFIG_ARCH_MVEBU)	+= mvebu/
 obj-$(CONFIG_ARCH_MXS)		+= mxs/
diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c
new file mode 100644
index 0000000..a4fc03d
--- /dev/null
+++ b/drivers/clk/clk-composite.c
@@ -0,0 +1,146 @@
+/*
+ * Taken from linux/drivers/clk/
+ *
+ * Copyright (c) 2013 NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <common.h>
+#include <io.h>
+#include <malloc.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+struct clk_composite {
+	struct clk	clk;
+
+	struct clk	*mux_clk;
+	struct clk	*rate_clk;
+	struct clk	*gate_clk;
+};
+
+static int clk_composite_get_parent(struct clk *clk)
+{
+	struct clk_composite *composite = container_of(clk, struct clk_composite, clk);
+	struct clk *mux_clk = composite->mux_clk;
+
+	return mux_clk?mux_clk->ops->get_parent(mux_clk):0;
+}
+
+static int clk_composite_set_parent(struct clk *clk, u8 index)
+{
+	struct clk_composite *composite = container_of(clk, struct clk_composite, clk);
+	struct clk *mux_clk = composite->mux_clk;
+
+	return mux_clk?mux_clk->ops->set_parent(mux_clk, index):0;
+}
+
+static unsigned long clk_composite_recalc_rate(struct clk *clk,
+					    unsigned long parent_rate)
+{
+	struct clk_composite *composite = container_of(clk, struct clk_composite, clk);
+	struct clk *rate_clk = composite->rate_clk;
+
+	return rate_clk?rate_clk->ops->recalc_rate(rate_clk, parent_rate):0;
+}
+
+static long clk_composite_round_rate(struct clk *clk, unsigned long rate,
+				  unsigned long *prate)
+{
+	struct clk_composite *composite = container_of(clk, struct clk_composite, clk);
+	struct clk *rate_clk = composite->rate_clk;
+
+	return rate_clk?rate_clk->ops->round_rate(rate_clk, rate, prate):0;
+}
+
+static int clk_composite_set_rate(struct clk *clk, unsigned long rate,
+			       unsigned long parent_rate)
+{
+	struct clk_composite *composite = container_of(clk, struct clk_composite, clk);
+	struct clk *rate_clk = composite->rate_clk;
+
+	return rate_clk?rate_clk->ops->set_rate(rate_clk, rate, parent_rate):0;
+}
+
+static int clk_composite_is_enabled(struct clk *clk)
+{
+	struct clk_composite *composite = container_of(clk, struct clk_composite, clk);
+	struct clk *gate_clk = composite->gate_clk;
+
+	return gate_clk?gate_clk->ops->is_enabled(gate_clk):0;
+}
+
+static int clk_composite_enable(struct clk *clk)
+{
+	struct clk_composite *composite = container_of(clk, struct clk_composite, clk);
+	struct clk *gate_clk = composite->gate_clk;
+
+	return gate_clk?gate_clk->ops->enable(gate_clk):0;
+}
+
+static void clk_composite_disable(struct clk *clk)
+{
+	struct clk_composite *composite = container_of(clk, struct clk_composite, clk);
+	struct clk *gate_clk = composite->gate_clk;
+
+	if(gate_clk)
+		gate_clk->ops->disable(gate_clk);
+}
+
+static struct clk_ops clk_composite_ops = {
+        .get_parent = clk_composite_get_parent,
+        .set_parent = clk_composite_set_parent,
+	.recalc_rate = clk_composite_recalc_rate,
+        .round_rate = clk_composite_round_rate,
+	.set_rate = clk_composite_set_rate,
+	.is_enabled = clk_composite_is_enabled,
+	.enable = clk_composite_enable,
+	.disable = clk_composite_disable,
+};
+
+struct clk *clk_register_composite(const char *name,
+			const char **parent_names, int num_parents,
+			struct clk *mux_clk,
+			struct clk *rate_clk,
+			struct clk *gate_clk,
+			unsigned long flags)
+{
+	struct clk_composite *composite;
+	int ret;
+
+	composite = kzalloc(sizeof(*composite), GFP_KERNEL);
+	if (!composite) {
+		pr_err("%s: could not allocate composite clk\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	composite->clk.name = name;
+	composite->clk.ops = &clk_composite_ops;
+	composite->clk.flags = flags;
+	composite->clk.parent_names = parent_names;
+	composite->clk.num_parents = num_parents;
+	composite->mux_clk = mux_clk;
+	composite->rate_clk = rate_clk;
+	composite->gate_clk = gate_clk;
+
+	ret = clk_register(&composite->clk);
+	if (ret)
+		goto err;
+
+	return &composite->clk;
+
+err:
+	kfree(composite);
+	return 0;
+}
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 49cb5a2..fe8ae5c 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -291,6 +291,12 @@ struct clk *clk_lookup(const char *name);
 
 void clk_dump(int verbose);
 
+struct clk *clk_register_composite(const char *name,
+			const char **parent_names, int num_parents,
+			struct clk *mux_clk,
+			struct clk *rate_clk,
+			struct clk *gate_clk,
+			unsigned long flags);
 #endif
 
 struct device_node;
-- 
2.1.4