drivers/clk/clk-xgene.c - kernel/msm-4.19 - Gitiles

 /*
  * clk-xgene.c - AppliedMicro X-Gene Clock Interface
  *
  * Copyright (c) 2013, Applied Micro Circuits Corporation
  * Author: Loc Ho <lho@apm.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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  * MA 02111-1307 USA
  *
  */
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/clkdev.h>
 #include <linux/clk-provider.h>
 #include <linux/of_address.h>
 #include <asm/setup.h>

 /* Register SCU_PCPPLL bit fields */
 #define N_DIV_RD(src)			(((src) & 0x000001ff))

 /* Register SCU_SOCPLL bit fields */
 #define CLKR_RD(src)			(((src) & 0x07000000)>>24)
 #define CLKOD_RD(src)			(((src) & 0x00300000)>>20)
 #define REGSPEC_RESET_F1_MASK		0x00010000
 #define CLKF_RD(src)			(((src) & 0x000001ff))

 #define XGENE_CLK_DRIVER_VER		"0.1"

 static DEFINE_SPINLOCK(clk_lock);

 static inline u32 xgene_clk_read(void __iomem *csr)
 {
 	return readl_relaxed(csr);
 }

 static inline void xgene_clk_write(u32 data, void __iomem *csr)
 {
 	return writel_relaxed(data, csr);
 }

 /* PLL Clock */
 enum xgene_pll_type {
 	PLL_TYPE_PCP = 0,
 	PLL_TYPE_SOC = 1,
 };

 struct xgene_clk_pll {
 	struct clk_hw	hw;
 	void __iomem	*reg;
 	spinlock_t	*lock;
 	u32		pll_offset;
 	enum xgene_pll_type	type;
 };

 #define to_xgene_clk_pll(_hw) container_of(_hw, struct xgene_clk_pll, hw)

 static int xgene_clk_pll_is_enabled(struct clk_hw *hw)
 {
 	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
 	u32 data;

 	data = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
 	pr_debug("%s pll %s\n", __clk_get_name(hw->clk),
 		data & REGSPEC_RESET_F1_MASK ? "disabled" : "enabled");

 	return data & REGSPEC_RESET_F1_MASK ? 0 : 1;
 }

 static unsigned long xgene_clk_pll_recalc_rate(struct clk_hw *hw,
 				unsigned long parent_rate)
 {
 	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
 	unsigned long fref;
 	unsigned long fvco;
 	u32 pll;
 	u32 nref;
 	u32 nout;
 	u32 nfb;

 	pll = xgene_clk_read(pllclk->reg + pllclk->pll_offset);

 	if (pllclk->type == PLL_TYPE_PCP) {
 		/*
 		 * PLL VCO = Reference clock * NF
 		 * PCP PLL = PLL_VCO / 2
 		 */
 		nout = 2;
 		fvco = parent_rate * (N_DIV_RD(pll) + 4);
 	} else {
 		/*
 		 * Fref = Reference Clock / NREF;
 		 * Fvco = Fref * NFB;
 		 * Fout = Fvco / NOUT;
 		 */
 		nref = CLKR_RD(pll) + 1;
 		nout = CLKOD_RD(pll) + 1;
 		nfb = CLKF_RD(pll);
 		fref = parent_rate / nref;
 		fvco = fref * nfb;
 	}
 	pr_debug("%s pll recalc rate %ld parent %ld\n", __clk_get_name(hw->clk),
 		fvco / nout, parent_rate);

 	return fvco / nout;
 }

 static const struct clk_ops xgene_clk_pll_ops = {
 	.is_enabled = xgene_clk_pll_is_enabled,
 	.recalc_rate = xgene_clk_pll_recalc_rate,
 };

 static struct clk *xgene_register_clk_pll(struct device *dev,
 	const char *name, const char *parent_name,
 	unsigned long flags, void __iomem *reg, u32 pll_offset,
 	u32 type, spinlock_t *lock)
 {
 	struct xgene_clk_pll *apmclk;
 	struct clk *clk;
 	struct clk_init_data init;

 	/* allocate the APM clock structure */
 	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
 	if (!apmclk) {
 		pr_err("%s: could not allocate APM clk\n", __func__);
 		return ERR_PTR(-ENOMEM);
 	}

 	init.name = name;
 	init.ops = &xgene_clk_pll_ops;
 	init.flags = flags;
 	init.parent_names = parent_name ? &parent_name : NULL;
 	init.num_parents = parent_name ? 1 : 0;

 	apmclk->reg = reg;
 	apmclk->lock = lock;
 	apmclk->pll_offset = pll_offset;
 	apmclk->type = type;
 	apmclk->hw.init = &init;

 	/* Register the clock */
 	clk = clk_register(dev, &apmclk->hw);
 	if (IS_ERR(clk)) {
 		pr_err("%s: could not register clk %s\n", __func__, name);
 		kfree(apmclk);
 		return NULL;
 	}
 	return clk;
 }

 static void xgene_pllclk_init(struct device_node *np, enum xgene_pll_type pll_type)
 {
         const char *clk_name = np->full_name;
         struct clk *clk;
         void __iomem *reg;

         reg = of_iomap(np, 0);
         if (reg == NULL) {
                 pr_err("Unable to map CSR register for %s\n", np->full_name);
                 return;
         }
         of_property_read_string(np, "clock-output-names", &clk_name);
         clk = xgene_register_clk_pll(NULL,
                         clk_name, of_clk_get_parent_name(np, 0),
                         CLK_IS_ROOT, reg, 0, pll_type, &clk_lock);
         if (!IS_ERR(clk)) {
                 of_clk_add_provider(np, of_clk_src_simple_get, clk);
                 clk_register_clkdev(clk, clk_name, NULL);
                 pr_debug("Add %s clock PLL\n", clk_name);
         }
 }

 static void xgene_socpllclk_init(struct device_node *np)
 {
 	xgene_pllclk_init(np, PLL_TYPE_SOC);
 }

 static void xgene_pcppllclk_init(struct device_node *np)
 {
 	xgene_pllclk_init(np, PLL_TYPE_PCP);
 }

 /* IP Clock */
 struct xgene_dev_parameters {
 	void __iomem *csr_reg;		/* CSR for IP clock */
 	u32 reg_clk_offset;		/* Offset to clock enable CSR */
 	u32 reg_clk_mask;		/* Mask bit for clock enable */
 	u32 reg_csr_offset;		/* Offset to CSR reset */
 	u32 reg_csr_mask;		/* Mask bit for disable CSR reset */
 	void __iomem *divider_reg;	/* CSR for divider */
 	u32 reg_divider_offset;		/* Offset to divider register */
 	u32 reg_divider_shift;		/* Bit shift to divider field */
 	u32 reg_divider_width;		/* Width of the bit to divider field */
 };

 struct xgene_clk {
 	struct clk_hw	hw;
 	spinlock_t	*lock;
 	struct xgene_dev_parameters	param;
 };

 #define to_xgene_clk(_hw) container_of(_hw, struct xgene_clk, hw)

 static int xgene_clk_enable(struct clk_hw *hw)
 {
 	struct xgene_clk *pclk = to_xgene_clk(hw);
 	unsigned long flags = 0;
 	u32 data;
 	phys_addr_t reg;

 	if (pclk->lock)
 		spin_lock_irqsave(pclk->lock, flags);

 	if (pclk->param.csr_reg != NULL) {
 		pr_debug("%s clock enabled\n", __clk_get_name(hw->clk));
 		reg = __pa(pclk->param.csr_reg);
 		/* First enable the clock */
 		data = xgene_clk_read(pclk->param.csr_reg +
 					pclk->param.reg_clk_offset);
 		data |= pclk->param.reg_clk_mask;
 		xgene_clk_write(data, pclk->param.csr_reg +
 					pclk->param.reg_clk_offset);
 		pr_debug("%s clock PADDR base %pa clk offset 0x%08X mask 0x%08X value 0x%08X\n",
 			__clk_get_name(hw->clk), &reg,
 			pclk->param.reg_clk_offset, pclk->param.reg_clk_mask,
 			data);

 		/* Second enable the CSR */
 		data = xgene_clk_read(pclk->param.csr_reg +
 					pclk->param.reg_csr_offset);
 		data &= ~pclk->param.reg_csr_mask;
 		xgene_clk_write(data, pclk->param.csr_reg +
 					pclk->param.reg_csr_offset);
 		pr_debug("%s CSR RESET PADDR base %pa csr offset 0x%08X mask 0x%08X value 0x%08X\n",
 			__clk_get_name(hw->clk), &reg,
 			pclk->param.reg_csr_offset, pclk->param.reg_csr_mask,
 			data);
 	}

 	if (pclk->lock)
 		spin_unlock_irqrestore(pclk->lock, flags);

 	return 0;
 }

 static void xgene_clk_disable(struct clk_hw *hw)
 {
 	struct xgene_clk *pclk = to_xgene_clk(hw);
 	unsigned long flags = 0;
 	u32 data;

 	if (pclk->lock)
 		spin_lock_irqsave(pclk->lock, flags);

 	if (pclk->param.csr_reg != NULL) {
 		pr_debug("%s clock disabled\n", __clk_get_name(hw->clk));
 		/* First put the CSR in reset */
 		data = xgene_clk_read(pclk->param.csr_reg +
 					pclk->param.reg_csr_offset);
 		data |= pclk->param.reg_csr_mask;
 		xgene_clk_write(data, pclk->param.csr_reg +
 					pclk->param.reg_csr_offset);

 		/* Second disable the clock */
 		data = xgene_clk_read(pclk->param.csr_reg +
 					pclk->param.reg_clk_offset);
 		data &= ~pclk->param.reg_clk_mask;
 		xgene_clk_write(data, pclk->param.csr_reg +
 					pclk->param.reg_clk_offset);
 	}

 	if (pclk->lock)
 		spin_unlock_irqrestore(pclk->lock, flags);
 }

 static int xgene_clk_is_enabled(struct clk_hw *hw)
 {
 	struct xgene_clk *pclk = to_xgene_clk(hw);
 	u32 data = 0;

 	if (pclk->param.csr_reg != NULL) {
 		pr_debug("%s clock checking\n", __clk_get_name(hw->clk));
 		data = xgene_clk_read(pclk->param.csr_reg +
 					pclk->param.reg_clk_offset);
 		pr_debug("%s clock is %s\n", __clk_get_name(hw->clk),
 			data & pclk->param.reg_clk_mask ? "enabled" :
 							"disabled");
 	}

 	if (pclk->param.csr_reg == NULL)
 		return 1;
 	return data & pclk->param.reg_clk_mask ? 1 : 0;
 }

 static unsigned long xgene_clk_recalc_rate(struct clk_hw *hw,
 				unsigned long parent_rate)
 {
 	struct xgene_clk *pclk = to_xgene_clk(hw);
 	u32 data;

 	if (pclk->param.divider_reg) {
 		data = xgene_clk_read(pclk->param.divider_reg +
 					pclk->param.reg_divider_offset);
 		data >>= pclk->param.reg_divider_shift;
 		data &= (1 << pclk->param.reg_divider_width) - 1;

 		pr_debug("%s clock recalc rate %ld parent %ld\n",
 			__clk_get_name(hw->clk),
 			parent_rate / data, parent_rate);

 		return parent_rate / data;
 	} else {
 		pr_debug("%s clock recalc rate %ld parent %ld\n",
 			__clk_get_name(hw->clk), parent_rate, parent_rate);
 		return parent_rate;
 	}
 }

 static int xgene_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 				unsigned long parent_rate)
 {
 	struct xgene_clk *pclk = to_xgene_clk(hw);
 	unsigned long flags = 0;
 	u32 data;
 	u32 divider;
 	u32 divider_save;

 	if (pclk->lock)
 		spin_lock_irqsave(pclk->lock, flags);

 	if (pclk->param.divider_reg) {
 		/* Let's compute the divider */
 		if (rate > parent_rate)
 			rate = parent_rate;
 		divider_save = divider = parent_rate / rate; /* Rounded down */
 		divider &= (1 << pclk->param.reg_divider_width) - 1;
 		divider <<= pclk->param.reg_divider_shift;

 		/* Set new divider */
 		data = xgene_clk_read(pclk->param.divider_reg +
 				pclk->param.reg_divider_offset);
 		data &= ~((1 << pclk->param.reg_divider_width) - 1);
 		data |= divider;
 		xgene_clk_write(data, pclk->param.divider_reg +
 					pclk->param.reg_divider_offset);
 		pr_debug("%s clock set rate %ld\n", __clk_get_name(hw->clk),
 			parent_rate / divider_save);
 	} else {
 		divider_save = 1;
 	}

 	if (pclk->lock)
 		spin_unlock_irqrestore(pclk->lock, flags);

 	return parent_rate / divider_save;
 }

 static long xgene_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 				unsigned long *prate)
 {
 	struct xgene_clk *pclk = to_xgene_clk(hw);
 	unsigned long parent_rate = *prate;
 	u32 divider;

 	if (pclk->param.divider_reg) {
 		/* Let's compute the divider */
 		if (rate > parent_rate)
 			rate = parent_rate;
 		divider = parent_rate / rate;   /* Rounded down */
 	} else {
 		divider = 1;
 	}

 	return parent_rate / divider;
 }

 static const struct clk_ops xgene_clk_ops = {
 	.enable = xgene_clk_enable,
 	.disable = xgene_clk_disable,
 	.is_enabled = xgene_clk_is_enabled,
 	.recalc_rate = xgene_clk_recalc_rate,
 	.set_rate = xgene_clk_set_rate,
 	.round_rate = xgene_clk_round_rate,
 };

 static struct clk *xgene_register_clk(struct device *dev,
 		const char *name, const char *parent_name,
 		struct xgene_dev_parameters *parameters, spinlock_t *lock)
 {
 	struct xgene_clk *apmclk;
 	struct clk *clk;
 	struct clk_init_data init;
 	int rc;

 	/* allocate the APM clock structure */
 	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
 	if (!apmclk) {
 		pr_err("%s: could not allocate APM clk\n", __func__);
 		return ERR_PTR(-ENOMEM);
 	}

 	init.name = name;
 	init.ops = &xgene_clk_ops;
 	init.flags = 0;
 	init.parent_names = parent_name ? &parent_name : NULL;
 	init.num_parents = parent_name ? 1 : 0;

 	apmclk->lock = lock;
 	apmclk->hw.init = &init;
 	apmclk->param = *parameters;

 	/* Register the clock */
 	clk = clk_register(dev, &apmclk->hw);
 	if (IS_ERR(clk)) {
 		pr_err("%s: could not register clk %s\n", __func__, name);
 		kfree(apmclk);
 		return clk;
 	}

 	/* Register the clock for lookup */
 	rc = clk_register_clkdev(clk, name, NULL);
 	if (rc != 0) {
 		pr_err("%s: could not register lookup clk %s\n",
 			__func__, name);
 	}
 	return clk;
 }

 static void __init xgene_devclk_init(struct device_node *np)
 {
 	const char *clk_name = np->full_name;
 	struct clk *clk;
 	struct resource res;
 	int rc;
 	struct xgene_dev_parameters parameters;
 	int i;

 	/* Check if the entry is disabled */
         if (!of_device_is_available(np))
                 return;

 	/* Parse the DTS register for resource */
 	parameters.csr_reg = NULL;
 	parameters.divider_reg = NULL;
 	for (i = 0; i < 2; i++) {
 		void __iomem *map_res;
 		rc = of_address_to_resource(np, i, &res);
 		if (rc != 0) {
 			if (i == 0) {
 				pr_err("no DTS register for %s\n",
 					np->full_name);
 				return;
 			}
 			break;
 		}
 		map_res = of_iomap(np, i);
 		if (map_res == NULL) {
 			pr_err("Unable to map resource %d for %s\n",
 				i, np->full_name);
 			goto err;
 		}
 		if (strcmp(res.name, "div-reg") == 0)
 			parameters.divider_reg = map_res;
 		else /* if (strcmp(res->name, "csr-reg") == 0) */
 			parameters.csr_reg = map_res;
 	}
 	if (of_property_read_u32(np, "csr-offset", &parameters.reg_csr_offset))
 		parameters.reg_csr_offset = 0;
 	if (of_property_read_u32(np, "csr-mask", &parameters.reg_csr_mask))
 		parameters.reg_csr_mask = 0xF;
 	if (of_property_read_u32(np, "enable-offset",
 				&parameters.reg_clk_offset))
 		parameters.reg_clk_offset = 0x8;
 	if (of_property_read_u32(np, "enable-mask", &parameters.reg_clk_mask))
 		parameters.reg_clk_mask = 0xF;
 	if (of_property_read_u32(np, "divider-offset",
 				&parameters.reg_divider_offset))
 		parameters.reg_divider_offset = 0;
 	if (of_property_read_u32(np, "divider-width",
 				&parameters.reg_divider_width))
 		parameters.reg_divider_width = 0;
 	if (of_property_read_u32(np, "divider-shift",
 				&parameters.reg_divider_shift))
 		parameters.reg_divider_shift = 0;
 	of_property_read_string(np, "clock-output-names", &clk_name);

 	clk = xgene_register_clk(NULL, clk_name,
 		of_clk_get_parent_name(np, 0), &parameters, &clk_lock);
 	if (IS_ERR(clk))
 		goto err;
 	pr_debug("Add %s clock\n", clk_name);
 	rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);
 	if (rc != 0)
 		pr_err("%s: could register provider clk %s\n", __func__,
 			np->full_name);

 	return;

 err:
 	if (parameters.csr_reg)
 		iounmap(parameters.csr_reg);
 	if (parameters.divider_reg)
 		iounmap(parameters.divider_reg);
 }

 CLK_OF_DECLARE(xgene_socpll_clock, "apm,xgene-socpll-clock", xgene_socpllclk_init);
 CLK_OF_DECLARE(xgene_pcppll_clock, "apm,xgene-pcppll-clock", xgene_pcppllclk_init);
 CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);
	/*
	* clk-xgene.c - AppliedMicro X-Gene Clock Interface
	*
	* Copyright (c) 2013, Applied Micro Circuits Corporation
	* Author: Loc Ho <lho@apm.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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	* MA 02111-1307 USA
	*
	*/
	#include <linux/module.h>
	#include <linux/spinlock.h>
	#include <linux/io.h>
	#include <linux/of.h>
	#include <linux/clkdev.h>
	#include <linux/clk-provider.h>
	#include <linux/of_address.h>
	#include <asm/setup.h>

	/* Register SCU_PCPPLL bit fields */
	#define N_DIV_RD(src) (((src) & 0x000001ff))

	/* Register SCU_SOCPLL bit fields */
	#define CLKR_RD(src) (((src) & 0x07000000)>>24)
	#define CLKOD_RD(src) (((src) & 0x00300000)>>20)
	#define REGSPEC_RESET_F1_MASK 0x00010000
	#define CLKF_RD(src) (((src) & 0x000001ff))

	#define XGENE_CLK_DRIVER_VER "0.1"

	static DEFINE_SPINLOCK(clk_lock);

	static inline u32 xgene_clk_read(void __iomem *csr)
	{
	return readl_relaxed(csr);
	}

	static inline void xgene_clk_write(u32 data, void __iomem *csr)
	{
	return writel_relaxed(data, csr);
	}

	/* PLL Clock */
	enum xgene_pll_type {
	PLL_TYPE_PCP = 0,
	PLL_TYPE_SOC = 1,
	};

	struct xgene_clk_pll {
	struct clk_hw hw;
	void __iomem *reg;
	spinlock_t *lock;
	u32 pll_offset;
	enum xgene_pll_type type;
	};

	#define to_xgene_clk_pll(_hw) container_of(_hw, struct xgene_clk_pll, hw)

	static int xgene_clk_pll_is_enabled(struct clk_hw *hw)
	{
	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
	u32 data;

	data = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
	pr_debug("%s pll %s\n", __clk_get_name(hw->clk),
	data & REGSPEC_RESET_F1_MASK ? "disabled" : "enabled");

	return data & REGSPEC_RESET_F1_MASK ? 0 : 1;
	}

	static unsigned long xgene_clk_pll_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
	unsigned long fref;
	unsigned long fvco;
	u32 pll;
	u32 nref;
	u32 nout;
	u32 nfb;

	pll = xgene_clk_read(pllclk->reg + pllclk->pll_offset);

	if (pllclk->type == PLL_TYPE_PCP) {
	/*
	* PLL VCO = Reference clock * NF
	* PCP PLL = PLL_VCO / 2
	*/
	nout = 2;
	fvco = parent_rate * (N_DIV_RD(pll) + 4);
	} else {
	/*
	* Fref = Reference Clock / NREF;
	* Fvco = Fref * NFB;
	* Fout = Fvco / NOUT;
	*/
	nref = CLKR_RD(pll) + 1;
	nout = CLKOD_RD(pll) + 1;
	nfb = CLKF_RD(pll);
	fref = parent_rate / nref;
	fvco = fref * nfb;
	}
	pr_debug("%s pll recalc rate %ld parent %ld\n", __clk_get_name(hw->clk),
	fvco / nout, parent_rate);

	return fvco / nout;
	}

	static const struct clk_ops xgene_clk_pll_ops = {
	.is_enabled = xgene_clk_pll_is_enabled,
	.recalc_rate = xgene_clk_pll_recalc_rate,
	};

	static struct clk xgene_register_clk_pll(struct device dev,
	const char name, const char parent_name,
	unsigned long flags, void __iomem *reg, u32 pll_offset,
	u32 type, spinlock_t *lock)
	{
	struct xgene_clk_pll *apmclk;
	struct clk *clk;
	struct clk_init_data init;

	/* allocate the APM clock structure */
	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
	if (!apmclk) {
	pr_err("%s: could not allocate APM clk\n", __func__);
	return ERR_PTR(-ENOMEM);
	}

	init.name = name;
	init.ops = &xgene_clk_pll_ops;
	init.flags = flags;
	init.parent_names = parent_name ? &parent_name : NULL;
	init.num_parents = parent_name ? 1 : 0;

	apmclk->reg = reg;
	apmclk->lock = lock;
	apmclk->pll_offset = pll_offset;
	apmclk->type = type;
	apmclk->hw.init = &init;

	/* Register the clock */
	clk = clk_register(dev, &apmclk->hw);
	if (IS_ERR(clk)) {
	pr_err("%s: could not register clk %s\n", __func__, name);
	kfree(apmclk);
	return NULL;
	}
	return clk;
	}

	static void xgene_pllclk_init(struct device_node *np, enum xgene_pll_type pll_type)
	{
	const char *clk_name = np->full_name;
	struct clk *clk;
	void __iomem *reg;

	reg = of_iomap(np, 0);
	if (reg == NULL) {
	pr_err("Unable to map CSR register for %s\n", np->full_name);
	return;
	}
	of_property_read_string(np, "clock-output-names", &clk_name);
	clk = xgene_register_clk_pll(NULL,
	clk_name, of_clk_get_parent_name(np, 0),
	CLK_IS_ROOT, reg, 0, pll_type, &clk_lock);
	if (!IS_ERR(clk)) {
	of_clk_add_provider(np, of_clk_src_simple_get, clk);
	clk_register_clkdev(clk, clk_name, NULL);
	pr_debug("Add %s clock PLL\n", clk_name);
	}
	}

	static void xgene_socpllclk_init(struct device_node *np)
	{
	xgene_pllclk_init(np, PLL_TYPE_SOC);
	}

	static void xgene_pcppllclk_init(struct device_node *np)
	{
	xgene_pllclk_init(np, PLL_TYPE_PCP);
	}

	/* IP Clock */
	struct xgene_dev_parameters {
	void __iomem csr_reg; / CSR for IP clock */
	u32 reg_clk_offset; /* Offset to clock enable CSR */
	u32 reg_clk_mask; /* Mask bit for clock enable */
	u32 reg_csr_offset; /* Offset to CSR reset */
	u32 reg_csr_mask; /* Mask bit for disable CSR reset */
	void __iomem divider_reg; / CSR for divider */
	u32 reg_divider_offset; /* Offset to divider register */
	u32 reg_divider_shift; /* Bit shift to divider field */
	u32 reg_divider_width; /* Width of the bit to divider field */
	};

	struct xgene_clk {
	struct clk_hw hw;
	spinlock_t *lock;
	struct xgene_dev_parameters param;
	};

	#define to_xgene_clk(_hw) container_of(_hw, struct xgene_clk, hw)

	static int xgene_clk_enable(struct clk_hw *hw)
	{
	struct xgene_clk *pclk = to_xgene_clk(hw);
	unsigned long flags = 0;
	u32 data;
	phys_addr_t reg;

	if (pclk->lock)
	spin_lock_irqsave(pclk->lock, flags);

	if (pclk->param.csr_reg != NULL) {
	pr_debug("%s clock enabled\n", __clk_get_name(hw->clk));
	reg = __pa(pclk->param.csr_reg);
	/* First enable the clock */
	data = xgene_clk_read(pclk->param.csr_reg +
	pclk->param.reg_clk_offset);
	data \|= pclk->param.reg_clk_mask;
	xgene_clk_write(data, pclk->param.csr_reg +
	pclk->param.reg_clk_offset);
	pr_debug("%s clock PADDR base %pa clk offset 0x%08X mask 0x%08X value 0x%08X\n",
	__clk_get_name(hw->clk), &reg,
	pclk->param.reg_clk_offset, pclk->param.reg_clk_mask,
	data);

	/* Second enable the CSR */
	data = xgene_clk_read(pclk->param.csr_reg +
	pclk->param.reg_csr_offset);
	data &= ~pclk->param.reg_csr_mask;
	xgene_clk_write(data, pclk->param.csr_reg +
	pclk->param.reg_csr_offset);
	pr_debug("%s CSR RESET PADDR base %pa csr offset 0x%08X mask 0x%08X value 0x%08X\n",
	__clk_get_name(hw->clk), &reg,
	pclk->param.reg_csr_offset, pclk->param.reg_csr_mask,
	data);
	}

	if (pclk->lock)
	spin_unlock_irqrestore(pclk->lock, flags);

	return 0;
	}

	static void xgene_clk_disable(struct clk_hw *hw)
	{
	struct xgene_clk *pclk = to_xgene_clk(hw);
	unsigned long flags = 0;
	u32 data;

	if (pclk->lock)
	spin_lock_irqsave(pclk->lock, flags);

	if (pclk->param.csr_reg != NULL) {
	pr_debug("%s clock disabled\n", __clk_get_name(hw->clk));
	/* First put the CSR in reset */
	data = xgene_clk_read(pclk->param.csr_reg +
	pclk->param.reg_csr_offset);
	data \|= pclk->param.reg_csr_mask;
	xgene_clk_write(data, pclk->param.csr_reg +
	pclk->param.reg_csr_offset);

	/* Second disable the clock */
	data = xgene_clk_read(pclk->param.csr_reg +
	pclk->param.reg_clk_offset);
	data &= ~pclk->param.reg_clk_mask;
	xgene_clk_write(data, pclk->param.csr_reg +
	pclk->param.reg_clk_offset);
	}

	if (pclk->lock)
	spin_unlock_irqrestore(pclk->lock, flags);
	}

	static int xgene_clk_is_enabled(struct clk_hw *hw)
	{
	struct xgene_clk *pclk = to_xgene_clk(hw);
	u32 data = 0;

	if (pclk->param.csr_reg != NULL) {
	pr_debug("%s clock checking\n", __clk_get_name(hw->clk));
	data = xgene_clk_read(pclk->param.csr_reg +
	pclk->param.reg_clk_offset);
	pr_debug("%s clock is %s\n", __clk_get_name(hw->clk),
	data & pclk->param.reg_clk_mask ? "enabled" :
	"disabled");
	}

	if (pclk->param.csr_reg == NULL)
	return 1;
	return data & pclk->param.reg_clk_mask ? 1 : 0;
	}

	static unsigned long xgene_clk_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	struct xgene_clk *pclk = to_xgene_clk(hw);
	u32 data;

	if (pclk->param.divider_reg) {
	data = xgene_clk_read(pclk->param.divider_reg +
	pclk->param.reg_divider_offset);
	data >>= pclk->param.reg_divider_shift;
	data &= (1 << pclk->param.reg_divider_width) - 1;

	pr_debug("%s clock recalc rate %ld parent %ld\n",
	__clk_get_name(hw->clk),
	parent_rate / data, parent_rate);

	return parent_rate / data;
	} else {
	pr_debug("%s clock recalc rate %ld parent %ld\n",
	__clk_get_name(hw->clk), parent_rate, parent_rate);
	return parent_rate;
	}
	}

	static int xgene_clk_set_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	struct xgene_clk *pclk = to_xgene_clk(hw);
	unsigned long flags = 0;
	u32 data;
	u32 divider;
	u32 divider_save;

	if (pclk->lock)
	spin_lock_irqsave(pclk->lock, flags);

	if (pclk->param.divider_reg) {
	/* Let's compute the divider */
	if (rate > parent_rate)
	rate = parent_rate;
	divider_save = divider = parent_rate / rate; /* Rounded down */
	divider &= (1 << pclk->param.reg_divider_width) - 1;
	divider <<= pclk->param.reg_divider_shift;

	/* Set new divider */
	data = xgene_clk_read(pclk->param.divider_reg +
	pclk->param.reg_divider_offset);
	data &= ~((1 << pclk->param.reg_divider_width) - 1);
	data \|= divider;
	xgene_clk_write(data, pclk->param.divider_reg +
	pclk->param.reg_divider_offset);
	pr_debug("%s clock set rate %ld\n", __clk_get_name(hw->clk),
	parent_rate / divider_save);
	} else {
	divider_save = 1;
	}

	if (pclk->lock)
	spin_unlock_irqrestore(pclk->lock, flags);

	return parent_rate / divider_save;
	}

	static long xgene_clk_round_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long *prate)
	{
	struct xgene_clk *pclk = to_xgene_clk(hw);
	unsigned long parent_rate = *prate;
	u32 divider;

	if (pclk->param.divider_reg) {
	/* Let's compute the divider */
	if (rate > parent_rate)
	rate = parent_rate;
	divider = parent_rate / rate; /* Rounded down */
	} else {
	divider = 1;
	}

	return parent_rate / divider;
	}

	static const struct clk_ops xgene_clk_ops = {
	.enable = xgene_clk_enable,
	.disable = xgene_clk_disable,
	.is_enabled = xgene_clk_is_enabled,
	.recalc_rate = xgene_clk_recalc_rate,
	.set_rate = xgene_clk_set_rate,
	.round_rate = xgene_clk_round_rate,
	};

	static struct clk xgene_register_clk(struct device dev,
	const char name, const char parent_name,
	struct xgene_dev_parameters parameters, spinlock_t lock)
	{
	struct xgene_clk *apmclk;
	struct clk *clk;
	struct clk_init_data init;
	int rc;

	/* allocate the APM clock structure */
	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
	if (!apmclk) {
	pr_err("%s: could not allocate APM clk\n", __func__);
	return ERR_PTR(-ENOMEM);
	}

	init.name = name;
	init.ops = &xgene_clk_ops;
	init.flags = 0;
	init.parent_names = parent_name ? &parent_name : NULL;
	init.num_parents = parent_name ? 1 : 0;

	apmclk->lock = lock;
	apmclk->hw.init = &init;
	apmclk->param = *parameters;

	/* Register the clock */
	clk = clk_register(dev, &apmclk->hw);
	if (IS_ERR(clk)) {
	pr_err("%s: could not register clk %s\n", __func__, name);
	kfree(apmclk);
	return clk;
	}

	/* Register the clock for lookup */
	rc = clk_register_clkdev(clk, name, NULL);
	if (rc != 0) {
	pr_err("%s: could not register lookup clk %s\n",
	__func__, name);
	}
	return clk;
	}

	static void __init xgene_devclk_init(struct device_node *np)
	{
	const char *clk_name = np->full_name;
	struct clk *clk;
	struct resource res;
	int rc;
	struct xgene_dev_parameters parameters;
	int i;

	/* Check if the entry is disabled */
	if (!of_device_is_available(np))
	return;

	/* Parse the DTS register for resource */
	parameters.csr_reg = NULL;
	parameters.divider_reg = NULL;
	for (i = 0; i < 2; i++) {
	void __iomem *map_res;
	rc = of_address_to_resource(np, i, &res);
	if (rc != 0) {
	if (i == 0) {
	pr_err("no DTS register for %s\n",
	np->full_name);
	return;
	}
	break;
	}
	map_res = of_iomap(np, i);
	if (map_res == NULL) {
	pr_err("Unable to map resource %d for %s\n",
	i, np->full_name);
	goto err;
	}
	if (strcmp(res.name, "div-reg") == 0)
	parameters.divider_reg = map_res;
	else /* if (strcmp(res->name, "csr-reg") == 0) */
	parameters.csr_reg = map_res;
	}
	if (of_property_read_u32(np, "csr-offset", &parameters.reg_csr_offset))
	parameters.reg_csr_offset = 0;
	if (of_property_read_u32(np, "csr-mask", &parameters.reg_csr_mask))
	parameters.reg_csr_mask = 0xF;
	if (of_property_read_u32(np, "enable-offset",
	&parameters.reg_clk_offset))
	parameters.reg_clk_offset = 0x8;
	if (of_property_read_u32(np, "enable-mask", &parameters.reg_clk_mask))
	parameters.reg_clk_mask = 0xF;
	if (of_property_read_u32(np, "divider-offset",
	&parameters.reg_divider_offset))
	parameters.reg_divider_offset = 0;
	if (of_property_read_u32(np, "divider-width",
	&parameters.reg_divider_width))
	parameters.reg_divider_width = 0;
	if (of_property_read_u32(np, "divider-shift",
	&parameters.reg_divider_shift))
	parameters.reg_divider_shift = 0;
	of_property_read_string(np, "clock-output-names", &clk_name);

	clk = xgene_register_clk(NULL, clk_name,
	of_clk_get_parent_name(np, 0), &parameters, &clk_lock);
	if (IS_ERR(clk))
	goto err;
	pr_debug("Add %s clock\n", clk_name);
	rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);
	if (rc != 0)
	pr_err("%s: could register provider clk %s\n", __func__,
	np->full_name);

	return;

	err:
	if (parameters.csr_reg)
	iounmap(parameters.csr_reg);
	if (parameters.divider_reg)
	iounmap(parameters.divider_reg);
	}

	CLK_OF_DECLARE(xgene_socpll_clock, "apm,xgene-socpll-clock", xgene_socpllclk_init);
	CLK_OF_DECLARE(xgene_pcppll_clock, "apm,xgene-pcppll-clock", xgene_pcppllclk_init);
	CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);