drivers/clk/samsung/clk.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
  * Copyright (c) 2013 Linaro Ltd.
  * Author: Thomas Abraham <thomas.ab@samsung.com>
  *
  * This file includes utility functions to register clocks to common
  * clock framework for Samsung platforms.
 */

 #include <linux/slab.h>
 #include <linux/clkdev.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/io.h>
 #include <linux/of_address.h>
 #include <linux/syscore_ops.h>

 #include "clk.h"

 static LIST_HEAD(clock_reg_cache_list);

 void samsung_clk_save(void __iomem *base,
 				    struct samsung_clk_reg_dump *rd,
 				    unsigned int num_regs)
 {
 	for (; num_regs > 0; --num_regs, ++rd)
 		rd->value = readl(base + rd->offset);
 }

 void samsung_clk_restore(void __iomem *base,
 				      const struct samsung_clk_reg_dump *rd,
 				      unsigned int num_regs)
 {
 	for (; num_regs > 0; --num_regs, ++rd)
 		writel(rd->value, base + rd->offset);
 }

 struct samsung_clk_reg_dump *samsung_clk_alloc_reg_dump(
 						const unsigned long *rdump,
 						unsigned long nr_rdump)
 {
 	struct samsung_clk_reg_dump *rd;
 	unsigned int i;

 	rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL);
 	if (!rd)
 		return NULL;

 	for (i = 0; i < nr_rdump; ++i)
 		rd[i].offset = rdump[i];

 	return rd;
 }

 /* setup the essentials required to support clock lookup using ccf */
 struct samsung_clk_provider *__init samsung_clk_init(struct device_node *np,
 			void __iomem *base, unsigned long nr_clks)
 {
 	struct samsung_clk_provider *ctx;
 	int i;

 	ctx = kzalloc(struct_size(ctx, clk_data.hws, nr_clks), GFP_KERNEL);
 	if (!ctx)
 		panic("could not allocate clock provider context.\n");

 	for (i = 0; i < nr_clks; ++i)
 		ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);

 	ctx->reg_base = base;
 	ctx->clk_data.num = nr_clks;
 	spin_lock_init(&ctx->lock);

 	return ctx;
 }

 void __init samsung_clk_of_add_provider(struct device_node *np,
 				struct samsung_clk_provider *ctx)
 {
 	if (np) {
 		if (of_clk_add_hw_provider(np, of_clk_hw_onecell_get,
 					&ctx->clk_data))
 			panic("could not register clk provider\n");
 	}
 }

 /* add a clock instance to the clock lookup table used for dt based lookup */
 void samsung_clk_add_lookup(struct samsung_clk_provider *ctx,
 			    struct clk_hw *clk_hw, unsigned int id)
 {
 	if (id)
 		ctx->clk_data.hws[id] = clk_hw;
 }

 /* register a list of aliases */
 void __init samsung_clk_register_alias(struct samsung_clk_provider *ctx,
 				const struct samsung_clock_alias *list,
 				unsigned int nr_clk)
 {
 	struct clk_hw *clk_hw;
 	unsigned int idx, ret;

 	for (idx = 0; idx < nr_clk; idx++, list++) {
 		if (!list->id) {
 			pr_err("%s: clock id missing for index %d\n", __func__,
 				idx);
 			continue;
 		}

 		clk_hw = ctx->clk_data.hws[list->id];
 		if (!clk_hw) {
 			pr_err("%s: failed to find clock %d\n", __func__,
 				list->id);
 			continue;
 		}

 		ret = clk_hw_register_clkdev(clk_hw, list->alias,
 					     list->dev_name);
 		if (ret)
 			pr_err("%s: failed to register lookup %s\n",
 					__func__, list->alias);
 	}
 }

 /* register a list of fixed clocks */
 void __init samsung_clk_register_fixed_rate(struct samsung_clk_provider *ctx,
 		const struct samsung_fixed_rate_clock *list,
 		unsigned int nr_clk)
 {
 	struct clk_hw *clk_hw;
 	unsigned int idx, ret;

 	for (idx = 0; idx < nr_clk; idx++, list++) {
 		clk_hw = clk_hw_register_fixed_rate(ctx->dev, list->name,
 			list->parent_name, list->flags, list->fixed_rate);
 		if (IS_ERR(clk_hw)) {
 			pr_err("%s: failed to register clock %s\n", __func__,
 				list->name);
 			continue;
 		}

 		samsung_clk_add_lookup(ctx, clk_hw, list->id);

 		/*
 		 * Unconditionally add a clock lookup for the fixed rate clocks.
 		 * There are not many of these on any of Samsung platforms.
 		 */
 		ret = clk_hw_register_clkdev(clk_hw, list->name, NULL);
 		if (ret)
 			pr_err("%s: failed to register clock lookup for %s",
 				__func__, list->name);
 	}
 }

 /* register a list of fixed factor clocks */
 void __init samsung_clk_register_fixed_factor(struct samsung_clk_provider *ctx,
 		const struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
 {
 	struct clk_hw *clk_hw;
 	unsigned int idx;

 	for (idx = 0; idx < nr_clk; idx++, list++) {
 		clk_hw = clk_hw_register_fixed_factor(ctx->dev, list->name,
 			list->parent_name, list->flags, list->mult, list->div);
 		if (IS_ERR(clk_hw)) {
 			pr_err("%s: failed to register clock %s\n", __func__,
 				list->name);
 			continue;
 		}

 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
 	}
 }

 /* register a list of mux clocks */
 void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx,
 				const struct samsung_mux_clock *list,
 				unsigned int nr_clk)
 {
 	struct clk_hw *clk_hw;
 	unsigned int idx;

 	for (idx = 0; idx < nr_clk; idx++, list++) {
 		clk_hw = clk_hw_register_mux(ctx->dev, list->name,
 			list->parent_names, list->num_parents, list->flags,
 			ctx->reg_base + list->offset,
 			list->shift, list->width, list->mux_flags, &ctx->lock);
 		if (IS_ERR(clk_hw)) {
 			pr_err("%s: failed to register clock %s\n", __func__,
 				list->name);
 			continue;
 		}

 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
 	}
 }

 /* register a list of div clocks */
 void __init samsung_clk_register_div(struct samsung_clk_provider *ctx,
 				const struct samsung_div_clock *list,
 				unsigned int nr_clk)
 {
 	struct clk_hw *clk_hw;
 	unsigned int idx;

 	for (idx = 0; idx < nr_clk; idx++, list++) {
 		if (list->table)
 			clk_hw = clk_hw_register_divider_table(ctx->dev,
 				list->name, list->parent_name, list->flags,
 				ctx->reg_base + list->offset,
 				list->shift, list->width, list->div_flags,
 				list->table, &ctx->lock);
 		else
 			clk_hw = clk_hw_register_divider(ctx->dev, list->name,
 				list->parent_name, list->flags,
 				ctx->reg_base + list->offset, list->shift,
 				list->width, list->div_flags, &ctx->lock);
 		if (IS_ERR(clk_hw)) {
 			pr_err("%s: failed to register clock %s\n", __func__,
 				list->name);
 			continue;
 		}

 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
 	}
 }

 /* register a list of gate clocks */
 void __init samsung_clk_register_gate(struct samsung_clk_provider *ctx,
 				const struct samsung_gate_clock *list,
 				unsigned int nr_clk)
 {
 	struct clk_hw *clk_hw;
 	unsigned int idx;

 	for (idx = 0; idx < nr_clk; idx++, list++) {
 		clk_hw = clk_hw_register_gate(ctx->dev, list->name, list->parent_name,
 				list->flags, ctx->reg_base + list->offset,
 				list->bit_idx, list->gate_flags, &ctx->lock);
 		if (IS_ERR(clk_hw)) {
 			pr_err("%s: failed to register clock %s\n", __func__,
 				list->name);
 			continue;
 		}

 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
 	}
 }

 /*
  * obtain the clock speed of all external fixed clock sources from device
  * tree and register it
  */
 void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx,
 			struct samsung_fixed_rate_clock *fixed_rate_clk,
 			unsigned int nr_fixed_rate_clk,
 			const struct of_device_id *clk_matches)
 {
 	const struct of_device_id *match;
 	struct device_node *clk_np;
 	u32 freq;

 	for_each_matching_node_and_match(clk_np, clk_matches, &match) {
 		if (of_property_read_u32(clk_np, "clock-frequency", &freq))
 			continue;
 		fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq;
 	}
 	samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk);
 }

 /* utility function to get the rate of a specified clock */
 unsigned long _get_rate(const char *clk_name)
 {
 	struct clk *clk;

 	clk = __clk_lookup(clk_name);
 	if (!clk) {
 		pr_err("%s: could not find clock %s\n", __func__, clk_name);
 		return 0;
 	}

 	return clk_get_rate(clk);
 }

 #ifdef CONFIG_PM_SLEEP
 static int samsung_clk_suspend(void)
 {
 	struct samsung_clock_reg_cache *reg_cache;

 	list_for_each_entry(reg_cache, &clock_reg_cache_list, node) {
 		samsung_clk_save(reg_cache->reg_base, reg_cache->rdump,
 				reg_cache->rd_num);
 		samsung_clk_restore(reg_cache->reg_base, reg_cache->rsuspend,
 				reg_cache->rsuspend_num);
 	}
 	return 0;
 }

 static void samsung_clk_resume(void)
 {
 	struct samsung_clock_reg_cache *reg_cache;

 	list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
 		samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump,
 				reg_cache->rd_num);
 }

 static struct syscore_ops samsung_clk_syscore_ops = {
 	.suspend = samsung_clk_suspend,
 	.resume = samsung_clk_resume,
 };

 void samsung_clk_extended_sleep_init(void __iomem *reg_base,
 			const unsigned long *rdump,
 			unsigned long nr_rdump,
 			const struct samsung_clk_reg_dump *rsuspend,
 			unsigned long nr_rsuspend)
 {
 	struct samsung_clock_reg_cache *reg_cache;

 	reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache),
 			GFP_KERNEL);
 	if (!reg_cache)
 		panic("could not allocate register reg_cache.\n");
 	reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump);

 	if (!reg_cache->rdump)
 		panic("could not allocate register dump storage.\n");

 	if (list_empty(&clock_reg_cache_list))
 		register_syscore_ops(&samsung_clk_syscore_ops);

 	reg_cache->reg_base = reg_base;
 	reg_cache->rd_num = nr_rdump;
 	reg_cache->rsuspend = rsuspend;
 	reg_cache->rsuspend_num = nr_rsuspend;
 	list_add_tail(&reg_cache->node, &clock_reg_cache_list);
 }
 #endif

 /*
  * Common function which registers plls, muxes, dividers and gates
  * for each CMU. It also add CMU register list to register cache.
  */
 struct samsung_clk_provider * __init samsung_cmu_register_one(
 			struct device_node *np,
 			const struct samsung_cmu_info *cmu)
 {
 	void __iomem *reg_base;
 	struct samsung_clk_provider *ctx;

 	reg_base = of_iomap(np, 0);
 	if (!reg_base) {
 		panic("%s: failed to map registers\n", __func__);
 		return NULL;
 	}

 	ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids);
 	if (!ctx) {
 		panic("%s: unable to allocate ctx\n", __func__);
 		return ctx;
 	}

 	if (cmu->pll_clks)
 		samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks,
 			reg_base);
 	if (cmu->mux_clks)
 		samsung_clk_register_mux(ctx, cmu->mux_clks,
 			cmu->nr_mux_clks);
 	if (cmu->div_clks)
 		samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks);
 	if (cmu->gate_clks)
 		samsung_clk_register_gate(ctx, cmu->gate_clks,
 			cmu->nr_gate_clks);
 	if (cmu->fixed_clks)
 		samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks,
 			cmu->nr_fixed_clks);
 	if (cmu->fixed_factor_clks)
 		samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks,
 			cmu->nr_fixed_factor_clks);
 	if (cmu->clk_regs)
 		samsung_clk_extended_sleep_init(reg_base,
 			cmu->clk_regs, cmu->nr_clk_regs,
 			cmu->suspend_regs, cmu->nr_suspend_regs);

 	samsung_clk_of_add_provider(np, ctx);

 	return ctx;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (c) 2013 Samsung Electronics Co., Ltd.
	* Copyright (c) 2013 Linaro Ltd.
	* Author: Thomas Abraham <thomas.ab@samsung.com>
	*
	* This file includes utility functions to register clocks to common
	* clock framework for Samsung platforms.
	*/

	#include <linux/slab.h>
	#include <linux/clkdev.h>
	#include <linux/clk.h>
	#include <linux/clk-provider.h>
	#include <linux/io.h>
	#include <linux/of_address.h>
	#include <linux/syscore_ops.h>

	#include "clk.h"

	static LIST_HEAD(clock_reg_cache_list);

	void samsung_clk_save(void __iomem *base,
	struct samsung_clk_reg_dump *rd,
	unsigned int num_regs)
	{
	for (; num_regs > 0; --num_regs, ++rd)
	rd->value = readl(base + rd->offset);
	}

	void samsung_clk_restore(void __iomem *base,
	const struct samsung_clk_reg_dump *rd,
	unsigned int num_regs)
	{
	for (; num_regs > 0; --num_regs, ++rd)
	writel(rd->value, base + rd->offset);
	}

	struct samsung_clk_reg_dump *samsung_clk_alloc_reg_dump(
	const unsigned long *rdump,
	unsigned long nr_rdump)
	{
	struct samsung_clk_reg_dump *rd;
	unsigned int i;

	rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL);
	if (!rd)
	return NULL;

	for (i = 0; i < nr_rdump; ++i)
	rd[i].offset = rdump[i];

	return rd;
	}

	/* setup the essentials required to support clock lookup using ccf */
	struct samsung_clk_provider __init samsung_clk_init(struct device_node np,
	void __iomem *base, unsigned long nr_clks)
	{
	struct samsung_clk_provider *ctx;
	int i;

	ctx = kzalloc(struct_size(ctx, clk_data.hws, nr_clks), GFP_KERNEL);
	if (!ctx)
	panic("could not allocate clock provider context.\n");

	for (i = 0; i < nr_clks; ++i)
	ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);

	ctx->reg_base = base;
	ctx->clk_data.num = nr_clks;
	spin_lock_init(&ctx->lock);

	return ctx;
	}

	void __init samsung_clk_of_add_provider(struct device_node *np,
	struct samsung_clk_provider *ctx)
	{
	if (np) {
	if (of_clk_add_hw_provider(np, of_clk_hw_onecell_get,
	&ctx->clk_data))
	panic("could not register clk provider\n");
	}
	}

	/* add a clock instance to the clock lookup table used for dt based lookup */
	void samsung_clk_add_lookup(struct samsung_clk_provider *ctx,
	struct clk_hw *clk_hw, unsigned int id)
	{
	if (id)
	ctx->clk_data.hws[id] = clk_hw;
	}

	/* register a list of aliases */
	void __init samsung_clk_register_alias(struct samsung_clk_provider *ctx,
	const struct samsung_clock_alias *list,
	unsigned int nr_clk)
	{
	struct clk_hw *clk_hw;
	unsigned int idx, ret;

	for (idx = 0; idx < nr_clk; idx++, list++) {
	if (!list->id) {
	pr_err("%s: clock id missing for index %d\n", __func__,
	idx);
	continue;
	}

	clk_hw = ctx->clk_data.hws[list->id];
	if (!clk_hw) {
	pr_err("%s: failed to find clock %d\n", __func__,
	list->id);
	continue;
	}

	ret = clk_hw_register_clkdev(clk_hw, list->alias,
	list->dev_name);
	if (ret)
	pr_err("%s: failed to register lookup %s\n",
	__func__, list->alias);
	}
	}

	/* register a list of fixed clocks */
	void __init samsung_clk_register_fixed_rate(struct samsung_clk_provider *ctx,
	const struct samsung_fixed_rate_clock *list,
	unsigned int nr_clk)
	{
	struct clk_hw *clk_hw;
	unsigned int idx, ret;

	for (idx = 0; idx < nr_clk; idx++, list++) {
	clk_hw = clk_hw_register_fixed_rate(ctx->dev, list->name,
	list->parent_name, list->flags, list->fixed_rate);
	if (IS_ERR(clk_hw)) {
	pr_err("%s: failed to register clock %s\n", __func__,
	list->name);
	continue;
	}

	samsung_clk_add_lookup(ctx, clk_hw, list->id);

	/*
	* Unconditionally add a clock lookup for the fixed rate clocks.
	* There are not many of these on any of Samsung platforms.
	*/
	ret = clk_hw_register_clkdev(clk_hw, list->name, NULL);
	if (ret)
	pr_err("%s: failed to register clock lookup for %s",
	__func__, list->name);
	}
	}

	/* register a list of fixed factor clocks */
	void __init samsung_clk_register_fixed_factor(struct samsung_clk_provider *ctx,
	const struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
	{
	struct clk_hw *clk_hw;
	unsigned int idx;

	for (idx = 0; idx < nr_clk; idx++, list++) {
	clk_hw = clk_hw_register_fixed_factor(ctx->dev, list->name,
	list->parent_name, list->flags, list->mult, list->div);
	if (IS_ERR(clk_hw)) {
	pr_err("%s: failed to register clock %s\n", __func__,
	list->name);
	continue;
	}

	samsung_clk_add_lookup(ctx, clk_hw, list->id);
	}
	}

	/* register a list of mux clocks */
	void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx,
	const struct samsung_mux_clock *list,
	unsigned int nr_clk)
	{
	struct clk_hw *clk_hw;
	unsigned int idx;

	for (idx = 0; idx < nr_clk; idx++, list++) {
	clk_hw = clk_hw_register_mux(ctx->dev, list->name,
	list->parent_names, list->num_parents, list->flags,
	ctx->reg_base + list->offset,
	list->shift, list->width, list->mux_flags, &ctx->lock);
	if (IS_ERR(clk_hw)) {
	pr_err("%s: failed to register clock %s\n", __func__,
	list->name);
	continue;
	}

	samsung_clk_add_lookup(ctx, clk_hw, list->id);
	}
	}

	/* register a list of div clocks */
	void __init samsung_clk_register_div(struct samsung_clk_provider *ctx,
	const struct samsung_div_clock *list,
	unsigned int nr_clk)
	{
	struct clk_hw *clk_hw;
	unsigned int idx;

	for (idx = 0; idx < nr_clk; idx++, list++) {
	if (list->table)
	clk_hw = clk_hw_register_divider_table(ctx->dev,
	list->name, list->parent_name, list->flags,
	ctx->reg_base + list->offset,
	list->shift, list->width, list->div_flags,
	list->table, &ctx->lock);
	else
	clk_hw = clk_hw_register_divider(ctx->dev, list->name,
	list->parent_name, list->flags,
	ctx->reg_base + list->offset, list->shift,
	list->width, list->div_flags, &ctx->lock);
	if (IS_ERR(clk_hw)) {
	pr_err("%s: failed to register clock %s\n", __func__,
	list->name);
	continue;
	}

	samsung_clk_add_lookup(ctx, clk_hw, list->id);
	}
	}

	/* register a list of gate clocks */
	void __init samsung_clk_register_gate(struct samsung_clk_provider *ctx,
	const struct samsung_gate_clock *list,
	unsigned int nr_clk)
	{
	struct clk_hw *clk_hw;
	unsigned int idx;

	for (idx = 0; idx < nr_clk; idx++, list++) {
	clk_hw = clk_hw_register_gate(ctx->dev, list->name, list->parent_name,
	list->flags, ctx->reg_base + list->offset,
	list->bit_idx, list->gate_flags, &ctx->lock);
	if (IS_ERR(clk_hw)) {
	pr_err("%s: failed to register clock %s\n", __func__,
	list->name);
	continue;
	}

	samsung_clk_add_lookup(ctx, clk_hw, list->id);
	}
	}

	/*
	* obtain the clock speed of all external fixed clock sources from device
	* tree and register it
	*/
	void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx,
	struct samsung_fixed_rate_clock *fixed_rate_clk,
	unsigned int nr_fixed_rate_clk,
	const struct of_device_id *clk_matches)
	{
	const struct of_device_id *match;
	struct device_node *clk_np;
	u32 freq;

	for_each_matching_node_and_match(clk_np, clk_matches, &match) {
	if (of_property_read_u32(clk_np, "clock-frequency", &freq))
	continue;
	fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq;
	}
	samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk);
	}

	/* utility function to get the rate of a specified clock */
	unsigned long _get_rate(const char *clk_name)
	{
	struct clk *clk;

	clk = __clk_lookup(clk_name);
	if (!clk) {
	pr_err("%s: could not find clock %s\n", __func__, clk_name);
	return 0;
	}

	return clk_get_rate(clk);
	}

	#ifdef CONFIG_PM_SLEEP
	static int samsung_clk_suspend(void)
	{
	struct samsung_clock_reg_cache *reg_cache;

	list_for_each_entry(reg_cache, &clock_reg_cache_list, node) {
	samsung_clk_save(reg_cache->reg_base, reg_cache->rdump,
	reg_cache->rd_num);
	samsung_clk_restore(reg_cache->reg_base, reg_cache->rsuspend,
	reg_cache->rsuspend_num);
	}
	return 0;
	}

	static void samsung_clk_resume(void)
	{
	struct samsung_clock_reg_cache *reg_cache;

	list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
	samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump,
	reg_cache->rd_num);
	}

	static struct syscore_ops samsung_clk_syscore_ops = {
	.suspend = samsung_clk_suspend,
	.resume = samsung_clk_resume,
	};

	void samsung_clk_extended_sleep_init(void __iomem *reg_base,
	const unsigned long *rdump,
	unsigned long nr_rdump,
	const struct samsung_clk_reg_dump *rsuspend,
	unsigned long nr_rsuspend)
	{
	struct samsung_clock_reg_cache *reg_cache;

	reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache),
	GFP_KERNEL);
	if (!reg_cache)
	panic("could not allocate register reg_cache.\n");
	reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump);

	if (!reg_cache->rdump)
	panic("could not allocate register dump storage.\n");

	if (list_empty(&clock_reg_cache_list))
	register_syscore_ops(&samsung_clk_syscore_ops);

	reg_cache->reg_base = reg_base;
	reg_cache->rd_num = nr_rdump;
	reg_cache->rsuspend = rsuspend;
	reg_cache->rsuspend_num = nr_rsuspend;
	list_add_tail(&reg_cache->node, &clock_reg_cache_list);
	}
	#endif

	/*
	* Common function which registers plls, muxes, dividers and gates
	* for each CMU. It also add CMU register list to register cache.
	*/
	struct samsung_clk_provider * __init samsung_cmu_register_one(
	struct device_node *np,
	const struct samsung_cmu_info *cmu)
	{
	void __iomem *reg_base;
	struct samsung_clk_provider *ctx;

	reg_base = of_iomap(np, 0);
	if (!reg_base) {
	panic("%s: failed to map registers\n", __func__);
	return NULL;
	}

	ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids);
	if (!ctx) {
	panic("%s: unable to allocate ctx\n", __func__);
	return ctx;
	}

	if (cmu->pll_clks)
	samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks,
	reg_base);
	if (cmu->mux_clks)
	samsung_clk_register_mux(ctx, cmu->mux_clks,
	cmu->nr_mux_clks);
	if (cmu->div_clks)
	samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks);
	if (cmu->gate_clks)
	samsung_clk_register_gate(ctx, cmu->gate_clks,
	cmu->nr_gate_clks);
	if (cmu->fixed_clks)
	samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks,
	cmu->nr_fixed_clks);
	if (cmu->fixed_factor_clks)
	samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks,
	cmu->nr_fixed_factor_clks);
	if (cmu->clk_regs)
	samsung_clk_extended_sleep_init(reg_base,
	cmu->clk_regs, cmu->nr_clk_regs,
	cmu->suspend_regs, cmu->nr_suspend_regs);

	samsung_clk_of_add_provider(np, ctx);

	return ctx;
	}