clk: mediatek: Add initial common clock support for Mediatek SoCs.

This patch adds common clock support for Mediatek SoCs, including plls,
muxes and clock gates.

Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Signed-off-by: Henry Chen <henryc.chen@mediatek.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
[sboyd@codeaurora.org: Squelch checkpatch warning in clk-mtk.h]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 137 insertions, 0 deletions

diff --git a/drivers/clk/mediatek/clk-gate.c b/drivers/clk/mediatek/clk-gate.c
new file mode 100644
index 000000000000..9d77ee3256f2
--- /dev/null
+++ b/drivers/clk/mediatek/clk-gate.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: James Liao <jamesjj.liao@mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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 <linux/of.h>
+#include <linux/of_address.h>
+
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/clkdev.h>
+
+#include "clk-mtk.h"
+#include "clk-gate.h"
+
+static int mtk_cg_bit_is_cleared(struct clk_hw *hw)
+{
+	struct mtk_clk_gate *cg = to_clk_gate(hw);
+	u32 val;
+
+	regmap_read(cg->regmap, cg->sta_ofs, &val);
+
+	val &= BIT(cg->bit);
+
+	return val == 0;
+}
+
+static int mtk_cg_bit_is_set(struct clk_hw *hw)
+{
+	struct mtk_clk_gate *cg = to_clk_gate(hw);
+	u32 val;
+
+	regmap_read(cg->regmap, cg->sta_ofs, &val);
+
+	val &= BIT(cg->bit);
+
+	return val != 0;
+}
+
+static void mtk_cg_set_bit(struct clk_hw *hw)
+{
+	struct mtk_clk_gate *cg = to_clk_gate(hw);
+
+	regmap_write(cg->regmap, cg->set_ofs, BIT(cg->bit));
+}
+
+static void mtk_cg_clr_bit(struct clk_hw *hw)
+{
+	struct mtk_clk_gate *cg = to_clk_gate(hw);
+
+	regmap_write(cg->regmap, cg->clr_ofs, BIT(cg->bit));
+}
+
+static int mtk_cg_enable(struct clk_hw *hw)
+{
+	mtk_cg_clr_bit(hw);
+
+	return 0;
+}
+
+static void mtk_cg_disable(struct clk_hw *hw)
+{
+	mtk_cg_set_bit(hw);
+}
+
+static int mtk_cg_enable_inv(struct clk_hw *hw)
+{
+	mtk_cg_set_bit(hw);
+
+	return 0;
+}
+
+static void mtk_cg_disable_inv(struct clk_hw *hw)
+{
+	mtk_cg_clr_bit(hw);
+}
+
+const struct clk_ops mtk_clk_gate_ops_setclr = {
+	.is_enabled	= mtk_cg_bit_is_cleared,
+	.enable		= mtk_cg_enable,
+	.disable	= mtk_cg_disable,
+};
+
+const struct clk_ops mtk_clk_gate_ops_setclr_inv = {
+	.is_enabled	= mtk_cg_bit_is_set,
+	.enable		= mtk_cg_enable_inv,
+	.disable	= mtk_cg_disable_inv,
+};
+
+struct clk *mtk_clk_register_gate(
+		const char *name,
+		const char *parent_name,
+		struct regmap *regmap,
+		int set_ofs,
+		int clr_ofs,
+		int sta_ofs,
+		u8 bit,
+		const struct clk_ops *ops)
+{
+	struct mtk_clk_gate *cg;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	cg = kzalloc(sizeof(*cg), GFP_KERNEL);
+	if (!cg)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.flags = CLK_SET_RATE_PARENT;
+	init.parent_names = parent_name ? &parent_name : NULL;
+	init.num_parents = parent_name ? 1 : 0;
+	init.ops = ops;
+
+	cg->regmap = regmap;
+	cg->set_ofs = set_ofs;
+	cg->clr_ofs = clr_ofs;
+	cg->sta_ofs = sta_ofs;
+	cg->bit = bit;
+
+	cg->hw.init = &init;
+
+	clk = clk_register(NULL, &cg->hw);
+	if (IS_ERR(clk))
+		kfree(cg);
+
+	return clk;
+}