drivers/clk/socfpga/clk.c - kernel/common - Git at Google

 /*
  *  Copyright 2011-2012 Calxeda, Inc.
  *  Copyright (C) 2012-2013 Altera Corporation <www.altera.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.
  *
  * Based from clk-highbank.c
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <linux/clk.h>
 #include <linux/clkdev.h>
 #include <linux/clk-provider.h>
 #include <linux/io.h>
 #include <linux/of.h>

 /* Clock Manager offsets */
 #define CLKMGR_CTRL	0x0
 #define CLKMGR_BYPASS	0x4
 #define CLKMGR_L4SRC	0x70
 #define CLKMGR_PERPLL_SRC	0xAC

 /* Clock bypass bits */
 #define MAINPLL_BYPASS		(1<<0)
 #define SDRAMPLL_BYPASS		(1<<1)
 #define SDRAMPLL_SRC_BYPASS	(1<<2)
 #define PERPLL_BYPASS		(1<<3)
 #define PERPLL_SRC_BYPASS	(1<<4)

 #define SOCFPGA_PLL_BG_PWRDWN		0
 #define SOCFPGA_PLL_EXT_ENA		1
 #define SOCFPGA_PLL_PWR_DOWN		2
 #define SOCFPGA_PLL_DIVF_MASK		0x0000FFF8
 #define SOCFPGA_PLL_DIVF_SHIFT	3
 #define SOCFPGA_PLL_DIVQ_MASK		0x003F0000
 #define SOCFPGA_PLL_DIVQ_SHIFT	16
 #define SOCFGPA_MAX_PARENTS	3

 #define SOCFPGA_L4_MP_CLK		"l4_mp_clk"
 #define SOCFPGA_L4_SP_CLK		"l4_sp_clk"
 #define SOCFPGA_NAND_CLK		"nand_clk"
 #define SOCFPGA_NAND_X_CLK		"nand_x_clk"
 #define SOCFPGA_MMC_CLK			"mmc_clk"
 #define SOCFPGA_DB_CLK			"gpio_db_clk"

 #define div_mask(width)	((1 << (width)) - 1)
 #define streq(a, b) (strcmp((a), (b)) == 0)

 extern void __iomem *clk_mgr_base_addr;

 struct socfpga_clk {
 	struct clk_gate hw;
 	char *parent_name;
 	char *clk_name;
 	u32 fixed_div;
 	void __iomem *div_reg;
 	u32 width;	/* only valid if div_reg != 0 */
 	u32 shift;	/* only valid if div_reg != 0 */
 };
 #define to_socfpga_clk(p) container_of(p, struct socfpga_clk, hw.hw)

 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
 					 unsigned long parent_rate)
 {
 	struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk);
 	unsigned long divf, divq, vco_freq, reg;
 	unsigned long bypass;

 	reg = readl(socfpgaclk->hw.reg);
 	bypass = readl(clk_mgr_base_addr + CLKMGR_BYPASS);
 	if (bypass & MAINPLL_BYPASS)
 		return parent_rate;

 	divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
 	divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
 	vco_freq = parent_rate * (divf + 1);
 	return vco_freq / (1 + divq);
 }


 static struct clk_ops clk_pll_ops = {
 	.recalc_rate = clk_pll_recalc_rate,
 };

 static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
 					     unsigned long parent_rate)
 {
 	struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk);
 	u32 div;

 	if (socfpgaclk->fixed_div)
 		div = socfpgaclk->fixed_div;
 	else
 		div = ((readl(socfpgaclk->hw.reg) & 0x1ff) + 1);

 	return parent_rate / div;
 }

 static const struct clk_ops periclk_ops = {
 	.recalc_rate = clk_periclk_recalc_rate,
 };

 static __init struct clk *socfpga_clk_init(struct device_node *node,
 	const struct clk_ops *ops)
 {
 	u32 reg;
 	struct clk *clk;
 	struct socfpga_clk *socfpga_clk;
 	const char *clk_name = node->name;
 	const char *parent_name;
 	struct clk_init_data init;
 	int rc;
 	u32 fixed_div;

 	rc = of_property_read_u32(node, "reg", &reg);
 	if (WARN_ON(rc))
 		return NULL;

 	socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
 	if (WARN_ON(!socfpga_clk))
 		return NULL;

 	socfpga_clk->hw.reg = clk_mgr_base_addr + reg;

 	rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
 	if (rc)
 		socfpga_clk->fixed_div = 0;
 	else
 		socfpga_clk->fixed_div = fixed_div;

 	of_property_read_string(node, "clock-output-names", &clk_name);

 	init.name = clk_name;
 	init.ops = ops;
 	init.flags = 0;
 	parent_name = of_clk_get_parent_name(node, 0);
 	init.parent_names = &parent_name;
 	init.num_parents = 1;

 	socfpga_clk->hw.hw.init = &init;

 	if (streq(clk_name, "main_pll") ||
 		streq(clk_name, "periph_pll") ||
 		streq(clk_name, "sdram_pll")) {
 		socfpga_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA;
 		clk_pll_ops.enable = clk_gate_ops.enable;
 		clk_pll_ops.disable = clk_gate_ops.disable;
 	}

 	clk = clk_register(NULL, &socfpga_clk->hw.hw);
 	if (WARN_ON(IS_ERR(clk))) {
 		kfree(socfpga_clk);
 		return NULL;
 	}
 	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 	return clk;
 }

 static u8 socfpga_clk_get_parent(struct clk_hw *hwclk)
 {
 	u32 l4_src;
 	u32 perpll_src;

 	if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
 		l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
 		return l4_src &= 0x1;
 	}
 	if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
 		l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
 		return !!(l4_src & 2);
 	}

 	perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
 	if (streq(hwclk->init->name, SOCFPGA_MMC_CLK))
 		return perpll_src &= 0x3;
 	if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) ||
 			streq(hwclk->init->name, SOCFPGA_NAND_X_CLK))
 			return (perpll_src >> 2) & 3;

 	/* QSPI clock */
 	return (perpll_src >> 4) & 3;

 }

 static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent)
 {
 	u32 src_reg;

 	if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
 		src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
 		src_reg &= ~0x1;
 		src_reg |= parent;
 		writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
 	} else if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
 		src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
 		src_reg &= ~0x2;
 		src_reg |= (parent << 1);
 		writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
 	} else {
 		src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
 		if (streq(hwclk->init->name, SOCFPGA_MMC_CLK)) {
 			src_reg &= ~0x3;
 			src_reg |= parent;
 		} else if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) ||
 			streq(hwclk->init->name, SOCFPGA_NAND_X_CLK)) {
 			src_reg &= ~0xC;
 			src_reg |= (parent << 2);
 		} else {/* QSPI clock */
 			src_reg &= ~0x30;
 			src_reg |= (parent << 4);
 		}
 		writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
 	}

 	return 0;
 }

 static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
 	unsigned long parent_rate)
 {
 	struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk);
 	u32 div = 1, val;

 	if (socfpgaclk->fixed_div)
 		div = socfpgaclk->fixed_div;
 	else if (socfpgaclk->div_reg) {
 		val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
 		val &= div_mask(socfpgaclk->width);
 		if (streq(hwclk->init->name, SOCFPGA_DB_CLK))
 			div = val + 1;
 		else
 			div = (1 << val);
 	}

 	return parent_rate / div;
 }

 static struct clk_ops gateclk_ops = {
 	.recalc_rate = socfpga_clk_recalc_rate,
 	.get_parent = socfpga_clk_get_parent,
 	.set_parent = socfpga_clk_set_parent,
 };

 static void __init socfpga_gate_clk_init(struct device_node *node,
 	const struct clk_ops *ops)
 {
 	u32 clk_gate[2];
 	u32 div_reg[3];
 	u32 fixed_div;
 	struct clk *clk;
 	struct socfpga_clk *socfpga_clk;
 	const char *clk_name = node->name;
 	const char *parent_name[SOCFGPA_MAX_PARENTS];
 	struct clk_init_data init;
 	int rc;
 	int i = 0;

 	socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
 	if (WARN_ON(!socfpga_clk))
 		return;

 	rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
 	if (rc)
 		clk_gate[0] = 0;

 	if (clk_gate[0]) {
 		socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0];
 		socfpga_clk->hw.bit_idx = clk_gate[1];

 		gateclk_ops.enable = clk_gate_ops.enable;
 		gateclk_ops.disable = clk_gate_ops.disable;
 	}

 	rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
 	if (rc)
 		socfpga_clk->fixed_div = 0;
 	else
 		socfpga_clk->fixed_div = fixed_div;

 	rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
 	if (!rc) {
 		socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0];
 		socfpga_clk->shift = div_reg[1];
 		socfpga_clk->width = div_reg[2];
 	} else {
 		socfpga_clk->div_reg = 0;
 	}

 	of_property_read_string(node, "clock-output-names", &clk_name);

 	init.name = clk_name;
 	init.ops = ops;
 	init.flags = 0;
 	while (i < SOCFGPA_MAX_PARENTS && (parent_name[i] =
 			of_clk_get_parent_name(node, i)) != NULL)
 		i++;

 	init.parent_names = parent_name;
 	init.num_parents = i;
 	socfpga_clk->hw.hw.init = &init;

 	clk = clk_register(NULL, &socfpga_clk->hw.hw);
 	if (WARN_ON(IS_ERR(clk))) {
 		kfree(socfpga_clk);
 		return;
 	}
 	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
 	if (WARN_ON(rc))
 		return;
 }

 static void __init socfpga_pll_init(struct device_node *node)
 {
 	socfpga_clk_init(node, &clk_pll_ops);
 }
 CLK_OF_DECLARE(socfpga_pll, "altr,socfpga-pll-clock", socfpga_pll_init);

 static void __init socfpga_periph_init(struct device_node *node)
 {
 	socfpga_clk_init(node, &periclk_ops);
 }
 CLK_OF_DECLARE(socfpga_periph, "altr,socfpga-perip-clk", socfpga_periph_init);

 static void __init socfpga_gate_init(struct device_node *node)
 {
 	socfpga_gate_clk_init(node, &gateclk_ops);
 }
 CLK_OF_DECLARE(socfpga_gate, "altr,socfpga-gate-clk", socfpga_gate_init);

 void __init socfpga_init_clocks(void)
 {
 	struct clk *clk;
 	int ret;

 	clk = clk_register_fixed_factor(NULL, "smp_twd", "mpuclk", 0, 1, 4);
 	ret = clk_register_clkdev(clk, NULL, "smp_twd");
 	if (ret)
 		pr_err("smp_twd alias not registered\n");
 }
	/*
	* Copyright 2011-2012 Calxeda, Inc.
	* Copyright (C) 2012-2013 Altera Corporation <www.altera.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.
	*
	* Based from clk-highbank.c
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*/
	#include <linux/clk.h>
	#include <linux/clkdev.h>
	#include <linux/clk-provider.h>
	#include <linux/io.h>
	#include <linux/of.h>

	/* Clock Manager offsets */
	#define CLKMGR_CTRL 0x0
	#define CLKMGR_BYPASS 0x4
	#define CLKMGR_L4SRC 0x70
	#define CLKMGR_PERPLL_SRC 0xAC

	/* Clock bypass bits */
	#define MAINPLL_BYPASS (1<<0)
	#define SDRAMPLL_BYPASS (1<<1)
	#define SDRAMPLL_SRC_BYPASS (1<<2)
	#define PERPLL_BYPASS (1<<3)
	#define PERPLL_SRC_BYPASS (1<<4)

	#define SOCFPGA_PLL_BG_PWRDWN 0
	#define SOCFPGA_PLL_EXT_ENA 1
	#define SOCFPGA_PLL_PWR_DOWN 2
	#define SOCFPGA_PLL_DIVF_MASK 0x0000FFF8
	#define SOCFPGA_PLL_DIVF_SHIFT 3
	#define SOCFPGA_PLL_DIVQ_MASK 0x003F0000
	#define SOCFPGA_PLL_DIVQ_SHIFT 16
	#define SOCFGPA_MAX_PARENTS 3

	#define SOCFPGA_L4_MP_CLK "l4_mp_clk"
	#define SOCFPGA_L4_SP_CLK "l4_sp_clk"
	#define SOCFPGA_NAND_CLK "nand_clk"
	#define SOCFPGA_NAND_X_CLK "nand_x_clk"
	#define SOCFPGA_MMC_CLK "mmc_clk"
	#define SOCFPGA_DB_CLK "gpio_db_clk"

	#define div_mask(width) ((1 << (width)) - 1)
	#define streq(a, b) (strcmp((a), (b)) == 0)

	extern void __iomem *clk_mgr_base_addr;

	struct socfpga_clk {
	struct clk_gate hw;
	char *parent_name;
	char *clk_name;
	u32 fixed_div;
	void __iomem *div_reg;
	u32 width; /* only valid if div_reg != 0 */
	u32 shift; /* only valid if div_reg != 0 */
	};
	#define to_socfpga_clk(p) container_of(p, struct socfpga_clk, hw.hw)

	static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
	unsigned long parent_rate)
	{
	struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk);
	unsigned long divf, divq, vco_freq, reg;
	unsigned long bypass;

	reg = readl(socfpgaclk->hw.reg);
	bypass = readl(clk_mgr_base_addr + CLKMGR_BYPASS);
	if (bypass & MAINPLL_BYPASS)
	return parent_rate;

	divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
	divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
	vco_freq = parent_rate * (divf + 1);
	return vco_freq / (1 + divq);
	}


	static struct clk_ops clk_pll_ops = {
	.recalc_rate = clk_pll_recalc_rate,
	};

	static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
	unsigned long parent_rate)
	{
	struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk);
	u32 div;

	if (socfpgaclk->fixed_div)
	div = socfpgaclk->fixed_div;
	else
	div = ((readl(socfpgaclk->hw.reg) & 0x1ff) + 1);

	return parent_rate / div;
	}

	static const struct clk_ops periclk_ops = {
	.recalc_rate = clk_periclk_recalc_rate,
	};

	static __init struct clk socfpga_clk_init(struct device_node node,
	const struct clk_ops *ops)
	{
	u32 reg;
	struct clk *clk;
	struct socfpga_clk *socfpga_clk;
	const char *clk_name = node->name;
	const char *parent_name;
	struct clk_init_data init;
	int rc;
	u32 fixed_div;

	rc = of_property_read_u32(node, "reg", &reg);
	if (WARN_ON(rc))
	return NULL;

	socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
	if (WARN_ON(!socfpga_clk))
	return NULL;

	socfpga_clk->hw.reg = clk_mgr_base_addr + reg;

	rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
	if (rc)
	socfpga_clk->fixed_div = 0;
	else
	socfpga_clk->fixed_div = fixed_div;

	of_property_read_string(node, "clock-output-names", &clk_name);

	init.name = clk_name;
	init.ops = ops;
	init.flags = 0;
	parent_name = of_clk_get_parent_name(node, 0);
	init.parent_names = &parent_name;
	init.num_parents = 1;

	socfpga_clk->hw.hw.init = &init;

	if (streq(clk_name, "main_pll") \|\|
	streq(clk_name, "periph_pll") \|\|
	streq(clk_name, "sdram_pll")) {
	socfpga_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA;
	clk_pll_ops.enable = clk_gate_ops.enable;
	clk_pll_ops.disable = clk_gate_ops.disable;
	}

	clk = clk_register(NULL, &socfpga_clk->hw.hw);
	if (WARN_ON(IS_ERR(clk))) {
	kfree(socfpga_clk);
	return NULL;
	}
	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
	return clk;
	}

	static u8 socfpga_clk_get_parent(struct clk_hw *hwclk)
	{
	u32 l4_src;
	u32 perpll_src;

	if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
	l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
	return l4_src &= 0x1;
	}
	if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
	l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
	return !!(l4_src & 2);
	}

	perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
	if (streq(hwclk->init->name, SOCFPGA_MMC_CLK))
	return perpll_src &= 0x3;
	if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) \|\|
	streq(hwclk->init->name, SOCFPGA_NAND_X_CLK))
	return (perpll_src >> 2) & 3;

	/* QSPI clock */
	return (perpll_src >> 4) & 3;

	}

	static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent)
	{
	u32 src_reg;

	if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) {
	src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
	src_reg &= ~0x1;
	src_reg \|= parent;
	writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
	} else if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) {
	src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
	src_reg &= ~0x2;
	src_reg \|= (parent << 1);
	writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
	} else {
	src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
	if (streq(hwclk->init->name, SOCFPGA_MMC_CLK)) {
	src_reg &= ~0x3;
	src_reg \|= parent;
	} else if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) \|\|
	streq(hwclk->init->name, SOCFPGA_NAND_X_CLK)) {
	src_reg &= ~0xC;
	src_reg \|= (parent << 2);
	} else {/* QSPI clock */
	src_reg &= ~0x30;
	src_reg \|= (parent << 4);
	}
	writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
	}

	return 0;
	}

	static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
	unsigned long parent_rate)
	{
	struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk);
	u32 div = 1, val;

	if (socfpgaclk->fixed_div)
	div = socfpgaclk->fixed_div;
	else if (socfpgaclk->div_reg) {
	val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
	val &= div_mask(socfpgaclk->width);
	if (streq(hwclk->init->name, SOCFPGA_DB_CLK))
	div = val + 1;
	else
	div = (1 << val);
	}

	return parent_rate / div;
	}

	static struct clk_ops gateclk_ops = {
	.recalc_rate = socfpga_clk_recalc_rate,
	.get_parent = socfpga_clk_get_parent,
	.set_parent = socfpga_clk_set_parent,
	};

	static void __init socfpga_gate_clk_init(struct device_node *node,
	const struct clk_ops *ops)
	{
	u32 clk_gate[2];
	u32 div_reg[3];
	u32 fixed_div;
	struct clk *clk;
	struct socfpga_clk *socfpga_clk;
	const char *clk_name = node->name;
	const char *parent_name[SOCFGPA_MAX_PARENTS];
	struct clk_init_data init;
	int rc;
	int i = 0;

	socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
	if (WARN_ON(!socfpga_clk))
	return;

	rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
	if (rc)
	clk_gate[0] = 0;

	if (clk_gate[0]) {
	socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0];
	socfpga_clk->hw.bit_idx = clk_gate[1];

	gateclk_ops.enable = clk_gate_ops.enable;
	gateclk_ops.disable = clk_gate_ops.disable;
	}

	rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
	if (rc)
	socfpga_clk->fixed_div = 0;
	else
	socfpga_clk->fixed_div = fixed_div;

	rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
	if (!rc) {
	socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0];
	socfpga_clk->shift = div_reg[1];
	socfpga_clk->width = div_reg[2];
	} else {
	socfpga_clk->div_reg = 0;
	}

	of_property_read_string(node, "clock-output-names", &clk_name);

	init.name = clk_name;
	init.ops = ops;
	init.flags = 0;
	while (i < SOCFGPA_MAX_PARENTS && (parent_name[i] =
	of_clk_get_parent_name(node, i)) != NULL)
	i++;

	init.parent_names = parent_name;
	init.num_parents = i;
	socfpga_clk->hw.hw.init = &init;

	clk = clk_register(NULL, &socfpga_clk->hw.hw);
	if (WARN_ON(IS_ERR(clk))) {
	kfree(socfpga_clk);
	return;
	}
	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
	if (WARN_ON(rc))
	return;
	}

	static void __init socfpga_pll_init(struct device_node *node)
	{
	socfpga_clk_init(node, &clk_pll_ops);
	}
	CLK_OF_DECLARE(socfpga_pll, "altr,socfpga-pll-clock", socfpga_pll_init);

	static void __init socfpga_periph_init(struct device_node *node)
	{
	socfpga_clk_init(node, &periclk_ops);
	}
	CLK_OF_DECLARE(socfpga_periph, "altr,socfpga-perip-clk", socfpga_periph_init);

	static void __init socfpga_gate_init(struct device_node *node)
	{
	socfpga_gate_clk_init(node, &gateclk_ops);
	}
	CLK_OF_DECLARE(socfpga_gate, "altr,socfpga-gate-clk", socfpga_gate_init);

	void __init socfpga_init_clocks(void)
	{
	struct clk *clk;
	int ret;

	clk = clk_register_fixed_factor(NULL, "smp_twd", "mpuclk", 0, 1, 4);
	ret = clk_register_clkdev(clk, NULL, "smp_twd");
	if (ret)
	pr_err("smp_twd alias not registered\n");
	}