clk: uniphier: add core support code for UniPhier clock driver

This includes UniPhier clock driver code, except SoC-specific
data arrays.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

MAINTAINERS

@@ -1828,6 +1828,7 @@ F:	arch/arm/mach-uniphier/
 F:	arch/arm/mm/cache-uniphier.c
 F:	arch/arm64/boot/dts/socionext/
 F:	drivers/bus/uniphier-system-bus.c
+F:	drivers/clk/uniphier/
 F:	drivers/i2c/busses/i2c-uniphier*
 F:	drivers/pinctrl/uniphier/
 F:	drivers/tty/serial/8250/8250_uniphier.c

drivers/clk/Kconfig

@@ -209,5 +209,6 @@ source "drivers/clk/samsung/Kconfig"
 source "drivers/clk/sunxi-ng/Kconfig"
 source "drivers/clk/tegra/Kconfig"
 source "drivers/clk/ti/Kconfig"
+source "drivers/clk/uniphier/Kconfig"
 
 endmenu

drivers/clk/Makefile

@@ -84,6 +84,7 @@ obj-$(CONFIG_ARCH_SUNXI)		+= sunxi/
 obj-$(CONFIG_ARCH_SUNXI)		+= sunxi-ng/
 obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
 obj-y					+= ti/
+obj-$(CONFIG_CLK_UNIPHIER)		+= uniphier/
 obj-$(CONFIG_ARCH_U8500)		+= ux500/
 obj-$(CONFIG_COMMON_CLK_VERSATILE)	+= versatile/
 obj-$(CONFIG_X86)			+= x86/

drivers/clk/uniphier/Kconfig

@@ -0,0 +1,9 @@
+config CLK_UNIPHIER
+	bool "Clock driver for UniPhier SoCs"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on OF && MFD_SYSCON
+	default ARCH_UNIPHIER
+	help
+	  Support for clock controllers on UniPhier SoCs.
+	  Say Y if you want to control clocks provided by System Control
+	  block, Media I/O block, Peripheral Block.

drivers/clk/uniphier/Makefile

@@ -0,0 +1,5 @@
+obj-y	+= clk-uniphier-core.o
+obj-y	+= clk-uniphier-fixed-factor.o
+obj-y	+= clk-uniphier-fixed-rate.o
+obj-y	+= clk-uniphier-gate.o
+obj-y	+= clk-uniphier-mux.o

drivers/clk/uniphier/clk-uniphier-core.c

@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2016 Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * 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 <linux/clk-provider.h>
+#include <linux/init.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#include "clk-uniphier.h"
+
+static struct clk_hw *uniphier_clk_register(struct device *dev,
+					    struct regmap *regmap,
+					const struct uniphier_clk_data *data)
+{
+	switch (data->type) {
+	case UNIPHIER_CLK_TYPE_FIXED_FACTOR:
+		return uniphier_clk_register_fixed_factor(dev, data->name,
+							  &data->data.factor);
+	case UNIPHIER_CLK_TYPE_FIXED_RATE:
+		return uniphier_clk_register_fixed_rate(dev, data->name,
+							&data->data.rate);
+	case UNIPHIER_CLK_TYPE_GATE:
+		return uniphier_clk_register_gate(dev, regmap, data->name,
+						  &data->data.gate);
+	case UNIPHIER_CLK_TYPE_MUX:
+		return uniphier_clk_register_mux(dev, regmap, data->name,
+						 &data->data.mux);
+	default:
+		dev_err(dev, "unsupported clock type\n");
+		return ERR_PTR(-EINVAL);
+	}
+}
+
+static int uniphier_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct clk_hw_onecell_data *hw_data;
+	const struct uniphier_clk_data *p, *data;
+	struct regmap *regmap;
+	struct device_node *parent;
+	int clk_num = 0;
+
+	data = of_device_get_match_data(dev);
+	if (WARN_ON(!data))
+		return -EINVAL;
+
+	parent = of_get_parent(dev->of_node); /* parent should be syscon node */
+	regmap = syscon_node_to_regmap(parent);
+	of_node_put(parent);
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "failed to get regmap (error %ld)\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	for (p = data; p->name; p++)
+		clk_num = max(clk_num, p->idx + 1);
+
+	hw_data = devm_kzalloc(dev,
+			sizeof(*hw_data) + clk_num * sizeof(struct clk_hw *),
+			GFP_KERNEL);
+	if (!hw_data)
+		return -ENOMEM;
+
+	hw_data->num = clk_num;
+
+	/* avoid returning NULL for unused idx */
+	for (; clk_num >= 0; clk_num--)
+		hw_data->hws[clk_num] = ERR_PTR(-EINVAL);
+
+	for (p = data; p->name; p++) {
+		struct clk_hw *hw;
+
+		dev_dbg(dev, "register %s (index=%d)\n", p->name, p->idx);
+		hw = uniphier_clk_register(dev, regmap, p);
+		if (IS_ERR(hw)) {
+			dev_err(dev, "failed to register %s (error %ld)\n",
+				p->name, PTR_ERR(hw));
+			return PTR_ERR(hw);
+		}
+
+		if (p->idx >= 0)
+			hw_data->hws[p->idx] = hw;
+	}
+
+	return of_clk_add_hw_provider(dev->of_node, of_clk_hw_onecell_get,
+				      hw_data);
+}
+
+static int uniphier_clk_remove(struct platform_device *pdev)
+{
+	of_clk_del_provider(pdev->dev.of_node);
+
+	return 0;
+}
+
+static const struct of_device_id uniphier_clk_match[] = {
+	{ /* sentinel */ }
+};
+
+static struct platform_driver uniphier_clk_driver = {
+	.probe = uniphier_clk_probe,
+	.remove = uniphier_clk_remove,
+	.driver = {
+		.name = "uniphier-clk",
+		.of_match_table = uniphier_clk_match,
+	},
+};
+builtin_platform_driver(uniphier_clk_driver);

drivers/clk/uniphier/clk-uniphier-fixed-factor.c

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2016 Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * 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 <linux/clk-provider.h>
+#include <linux/device.h>
+
+#include "clk-uniphier.h"
+
+struct clk_hw *uniphier_clk_register_fixed_factor(struct device *dev,
+						  const char *name,
+			const struct uniphier_clk_fixed_factor_data *data)
+{
+	struct clk_fixed_factor *fix;
+	struct clk_init_data init;
+	int ret;
+
+	fix = devm_kzalloc(dev, sizeof(*fix), GFP_KERNEL);
+	if (!fix)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &clk_fixed_factor_ops;
+	init.flags = data->parent_name ? CLK_SET_RATE_PARENT : 0;
+	init.parent_names = data->parent_name ? &data->parent_name : NULL;
+	init.num_parents = data->parent_name ? 1 : 0;
+
+	fix->mult = data->mult;
+	fix->div = data->div;
+	fix->hw.init = &init;
+
+	ret = devm_clk_hw_register(dev, &fix->hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return &fix->hw;
+}

drivers/clk/uniphier/clk-uniphier-fixed-rate.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2016 Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * 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 <linux/clk-provider.h>
+#include <linux/device.h>
+
+#include "clk-uniphier.h"
+
+struct clk_hw *uniphier_clk_register_fixed_rate(struct device *dev,
+						const char *name,
+				const struct uniphier_clk_fixed_rate_data *data)
+{
+	struct clk_fixed_rate *fixed;
+	struct clk_init_data init;
+	int ret;
+
+	/* allocate fixed-rate clock */
+	fixed = devm_kzalloc(dev, sizeof(*fixed), GFP_KERNEL);
+	if (!fixed)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &clk_fixed_rate_ops;
+	init.parent_names = NULL;
+	init.num_parents = 0;
+
+	fixed->fixed_rate = data->fixed_rate;
+	fixed->hw.init = &init;
+
+	ret = devm_clk_hw_register(dev, &fixed->hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return &fixed->hw;
+}

drivers/clk/uniphier/clk-uniphier-gate.c

@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2016 Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * 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 <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/regmap.h>
+
+#include "clk-uniphier.h"
+
+struct uniphier_clk_gate {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	unsigned int reg;
+	unsigned int bit;
+};
+
+#define to_uniphier_clk_gate(_hw) \
+				container_of(_hw, struct uniphier_clk_gate, hw)
+
+static int uniphier_clk_gate_endisable(struct clk_hw *hw, int enable)
+{
+	struct uniphier_clk_gate *gate = to_uniphier_clk_gate(hw);
+
+	return regmap_write_bits(gate->regmap, gate->reg, BIT(gate->bit),
+				 enable ? BIT(gate->bit) : 0);
+}
+
+static int uniphier_clk_gate_enable(struct clk_hw *hw)
+{
+	return uniphier_clk_gate_endisable(hw, 1);
+}
+
+static void uniphier_clk_gate_disable(struct clk_hw *hw)
+{
+	if (uniphier_clk_gate_endisable(hw, 0) < 0)
+		pr_warn("failed to disable clk\n");
+}
+
+static int uniphier_clk_gate_is_enabled(struct clk_hw *hw)
+{
+	struct uniphier_clk_gate *gate = to_uniphier_clk_gate(hw);
+	unsigned int val;
+
+	if (regmap_read(gate->regmap, gate->reg, &val) < 0)
+		pr_warn("is_enabled() may return wrong result\n");
+
+	return !!(val & BIT(gate->bit));
+}
+
+static const struct clk_ops uniphier_clk_gate_ops = {
+	.enable = uniphier_clk_gate_enable,
+	.disable = uniphier_clk_gate_disable,
+	.is_enabled = uniphier_clk_gate_is_enabled,
+};
+
+struct clk_hw *uniphier_clk_register_gate(struct device *dev,
+					  struct regmap *regmap,
+					  const char *name,
+				const struct uniphier_clk_gate_data *data)
+{
+	struct uniphier_clk_gate *gate;
+	struct clk_init_data init;
+	int ret;
+
+	gate = devm_kzalloc(dev, sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &uniphier_clk_gate_ops;
+	init.flags = data->parent_name ? CLK_SET_RATE_PARENT : 0;
+	init.parent_names = data->parent_name ? &data->parent_name : NULL;
+	init.num_parents = data->parent_name ? 1 : 0;
+
+	gate->regmap = regmap;
+	gate->reg = data->reg;
+	gate->bit = data->bit;
+	gate->hw.init = &init;
+
+	ret = devm_clk_hw_register(dev, &gate->hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return &gate->hw;
+}