clk: actions: Add common clock driver support

Add support for Actions Semi common clock driver with generic structures
and interface functions.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/Kconfig

@@ -238,6 +238,7 @@ config COMMON_CLK_VC5
 	  This driver supports the IDT VersaClock 5 and VersaClock 6
 	  programmable clock generators.
 
+source "drivers/clk/actions/Kconfig"
 source "drivers/clk/bcm/Kconfig"
 source "drivers/clk/hisilicon/Kconfig"
 source "drivers/clk/imgtec/Kconfig"

drivers/clk/Makefile

@@ -56,6 +56,7 @@ obj-$(CONFIG_COMMON_CLK_WM831X)		+= clk-wm831x.o
 obj-$(CONFIG_COMMON_CLK_XGENE)		+= clk-xgene.o
 
 # please keep this section sorted lexicographically by directory path name
+obj-y					+= actions/
 obj-$(CONFIG_COMMON_CLK_AT91)		+= at91/
 obj-$(CONFIG_ARCH_ARTPEC)		+= axis/
 obj-$(CONFIG_ARC_PLAT_AXS10X)		+= axs10x/

drivers/clk/actions/Kconfig

@@ -0,0 +1,4 @@
+config CLK_ACTIONS
+	bool "Clock driver for Actions Semi SoCs"
+	depends on ARCH_ACTIONS || COMPILE_TEST
+	default ARCH_ACTIONS

drivers/clk/actions/Makefile

@@ -0,0 +1,3 @@
+obj-$(CONFIG_CLK_ACTIONS)	+= clk-owl.o
+
+clk-owl-y			+= owl-common.o

drivers/clk/actions/owl-common.c

@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// OWL common clock driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <liuwei@actions-semi.com>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "owl-common.h"
+
+static const struct regmap_config owl_regmap_config = {
+	.reg_bits	= 32,
+	.reg_stride	= 4,
+	.val_bits	= 32,
+	.max_register	= 0x00cc,
+	.fast_io	= true,
+};
+
+static void owl_clk_set_regmap(const struct owl_clk_desc *desc,
+			 struct regmap *regmap)
+{
+	int i;
+	struct owl_clk_common *clks;
+
+	for (i = 0; i < desc->num_clks; i++) {
+		clks = desc->clks[i];
+		if (!clks)
+			continue;
+
+		clks->regmap = regmap;
+	}
+}
+
+int owl_clk_regmap_init(struct platform_device *pdev,
+			 const struct owl_clk_desc *desc)
+{
+	void __iomem *base;
+	struct regmap *regmap;
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(&pdev->dev, base, &owl_regmap_config);
+	if (IS_ERR(regmap)) {
+		pr_err("failed to init regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	owl_clk_set_regmap(desc, regmap);
+
+	return 0;
+}
+
+int owl_clk_probe(struct device *dev, struct clk_hw_onecell_data *hw_clks)
+{
+	int i, ret;
+	struct clk_hw *hw;
+
+	for (i = 0; i < hw_clks->num; i++) {
+
+		hw = hw_clks->hws[i];
+
+		if (IS_ERR_OR_NULL(hw))
+			continue;
+
+		ret = devm_clk_hw_register(dev, hw);
+		if (ret) {
+			dev_err(dev, "Couldn't register clock %d - %s\n",
+				i, hw->init->name);
+			return ret;
+		}
+	}
+
+	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, hw_clks);
+	if (ret)
+		dev_err(dev, "Failed to add clock provider\n");
+
+	return ret;
+}

drivers/clk/actions/owl-common.h

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// OWL common clock driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <liuwei@actions-semi.com>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+#ifndef _OWL_COMMON_H_
+#define _OWL_COMMON_H_
+
+#include <linux/clk-provider.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+
+struct device_node;
+
+struct owl_clk_common {
+	struct regmap			*regmap;
+	struct clk_hw			hw;
+};
+
+struct owl_clk_desc {
+	struct owl_clk_common		**clks;
+	unsigned long			num_clks;
+	struct clk_hw_onecell_data	*hw_clks;
+};
+
+static inline struct owl_clk_common *
+	hw_to_owl_clk_common(const struct clk_hw *hw)
+{
+	return container_of(hw, struct owl_clk_common, hw);
+}
+
+int owl_clk_regmap_init(struct platform_device *pdev,
+			 const struct owl_clk_desc *desc);
+int owl_clk_probe(struct device *dev, struct clk_hw_onecell_data *hw_clks);
+
+#endif /* _OWL_COMMON_H_ */