drivers/clk/at91/sckc.c - linux/torvalds/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * drivers/clk/at91/sckc.c
  *
  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
  */

 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
 #include <linux/delay.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/io.h>

 #define SLOW_CLOCK_FREQ		32768
 #define SLOWCK_SW_CYCLES	5
 #define SLOWCK_SW_TIME_USEC	((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
 				 SLOW_CLOCK_FREQ)

 #define	AT91_SCKC_CR			0x00
 #define		AT91_SCKC_RCEN		(1 << 0)
 #define		AT91_SCKC_OSC32EN	(1 << 1)
 #define		AT91_SCKC_OSC32BYP	(1 << 2)
 #define		AT91_SCKC_OSCSEL	(1 << 3)

 struct clk_slow_osc {
 	struct clk_hw hw;
 	void __iomem *sckcr;
 	unsigned long startup_usec;
 };

 #define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)

 struct clk_sama5d4_slow_osc {
 	struct clk_hw hw;
 	void __iomem *sckcr;
 	unsigned long startup_usec;
 	bool prepared;
 };

 #define to_clk_sama5d4_slow_osc(hw) container_of(hw, struct clk_sama5d4_slow_osc, hw)

 struct clk_slow_rc_osc {
 	struct clk_hw hw;
 	void __iomem *sckcr;
 	unsigned long frequency;
 	unsigned long accuracy;
 	unsigned long startup_usec;
 };

 #define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)

 struct clk_sam9x5_slow {
 	struct clk_hw hw;
 	void __iomem *sckcr;
 	u8 parent;
 };

 #define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)

 static int clk_slow_osc_prepare(struct clk_hw *hw)
 {
 	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
 	void __iomem *sckcr = osc->sckcr;
 	u32 tmp = readl(sckcr);

 	if (tmp & (AT91_SCKC_OSC32BYP | AT91_SCKC_OSC32EN))
 		return 0;

 	writel(tmp | AT91_SCKC_OSC32EN, sckcr);

 	usleep_range(osc->startup_usec, osc->startup_usec + 1);

 	return 0;
 }

 static void clk_slow_osc_unprepare(struct clk_hw *hw)
 {
 	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
 	void __iomem *sckcr = osc->sckcr;
 	u32 tmp = readl(sckcr);

 	if (tmp & AT91_SCKC_OSC32BYP)
 		return;

 	writel(tmp & ~AT91_SCKC_OSC32EN, sckcr);
 }

 static int clk_slow_osc_is_prepared(struct clk_hw *hw)
 {
 	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
 	void __iomem *sckcr = osc->sckcr;
 	u32 tmp = readl(sckcr);

 	if (tmp & AT91_SCKC_OSC32BYP)
 		return 1;

 	return !!(tmp & AT91_SCKC_OSC32EN);
 }

 static const struct clk_ops slow_osc_ops = {
 	.prepare = clk_slow_osc_prepare,
 	.unprepare = clk_slow_osc_unprepare,
 	.is_prepared = clk_slow_osc_is_prepared,
 };

 static struct clk_hw * __init
 at91_clk_register_slow_osc(void __iomem *sckcr,
 			   const char *name,
 			   const char *parent_name,
 			   unsigned long startup,
 			   bool bypass)
 {
 	struct clk_slow_osc *osc;
 	struct clk_hw *hw;
 	struct clk_init_data init;
 	int ret;

 	if (!sckcr || !name || !parent_name)
 		return ERR_PTR(-EINVAL);

 	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 	if (!osc)
 		return ERR_PTR(-ENOMEM);

 	init.name = name;
 	init.ops = &slow_osc_ops;
 	init.parent_names = &parent_name;
 	init.num_parents = 1;
 	init.flags = CLK_IGNORE_UNUSED;

 	osc->hw.init = &init;
 	osc->sckcr = sckcr;
 	osc->startup_usec = startup;

 	if (bypass)
 		writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) | AT91_SCKC_OSC32BYP,
 		       sckcr);

 	hw = &osc->hw;
 	ret = clk_hw_register(NULL, &osc->hw);
 	if (ret) {
 		kfree(osc);
 		hw = ERR_PTR(ret);
 	}

 	return hw;
 }

 static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
 						 unsigned long parent_rate)
 {
 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);

 	return osc->frequency;
 }

 static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
 						     unsigned long parent_acc)
 {
 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);

 	return osc->accuracy;
 }

 static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
 {
 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 	void __iomem *sckcr = osc->sckcr;

 	writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr);

 	usleep_range(osc->startup_usec, osc->startup_usec + 1);

 	return 0;
 }

 static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
 {
 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
 	void __iomem *sckcr = osc->sckcr;

 	writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr);
 }

 static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
 {
 	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);

 	return !!(readl(osc->sckcr) & AT91_SCKC_RCEN);
 }

 static const struct clk_ops slow_rc_osc_ops = {
 	.prepare = clk_slow_rc_osc_prepare,
 	.unprepare = clk_slow_rc_osc_unprepare,
 	.is_prepared = clk_slow_rc_osc_is_prepared,
 	.recalc_rate = clk_slow_rc_osc_recalc_rate,
 	.recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
 };

 static struct clk_hw * __init
 at91_clk_register_slow_rc_osc(void __iomem *sckcr,
 			      const char *name,
 			      unsigned long frequency,
 			      unsigned long accuracy,
 			      unsigned long startup)
 {
 	struct clk_slow_rc_osc *osc;
 	struct clk_hw *hw;
 	struct clk_init_data init;
 	int ret;

 	if (!sckcr || !name)
 		return ERR_PTR(-EINVAL);

 	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
 	if (!osc)
 		return ERR_PTR(-ENOMEM);

 	init.name = name;
 	init.ops = &slow_rc_osc_ops;
 	init.parent_names = NULL;
 	init.num_parents = 0;
 	init.flags = CLK_IGNORE_UNUSED;

 	osc->hw.init = &init;
 	osc->sckcr = sckcr;
 	osc->frequency = frequency;
 	osc->accuracy = accuracy;
 	osc->startup_usec = startup;

 	hw = &osc->hw;
 	ret = clk_hw_register(NULL, &osc->hw);
 	if (ret) {
 		kfree(osc);
 		hw = ERR_PTR(ret);
 	}

 	return hw;
 }

 static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
 {
 	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
 	void __iomem *sckcr = slowck->sckcr;
 	u32 tmp;

 	if (index > 1)
 		return -EINVAL;

 	tmp = readl(sckcr);

 	if ((!index && !(tmp & AT91_SCKC_OSCSEL)) ||
 	    (index && (tmp & AT91_SCKC_OSCSEL)))
 		return 0;

 	if (index)
 		tmp |= AT91_SCKC_OSCSEL;
 	else
 		tmp &= ~AT91_SCKC_OSCSEL;

 	writel(tmp, sckcr);

 	usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);

 	return 0;
 }

 static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
 {
 	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);

 	return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL);
 }

 static const struct clk_ops sam9x5_slow_ops = {
 	.set_parent = clk_sam9x5_slow_set_parent,
 	.get_parent = clk_sam9x5_slow_get_parent,
 };

 static struct clk_hw * __init
 at91_clk_register_sam9x5_slow(void __iomem *sckcr,
 			      const char *name,
 			      const char **parent_names,
 			      int num_parents)
 {
 	struct clk_sam9x5_slow *slowck;
 	struct clk_hw *hw;
 	struct clk_init_data init;
 	int ret;

 	if (!sckcr || !name || !parent_names || !num_parents)
 		return ERR_PTR(-EINVAL);

 	slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
 	if (!slowck)
 		return ERR_PTR(-ENOMEM);

 	init.name = name;
 	init.ops = &sam9x5_slow_ops;
 	init.parent_names = parent_names;
 	init.num_parents = num_parents;
 	init.flags = 0;

 	slowck->hw.init = &init;
 	slowck->sckcr = sckcr;
 	slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL);

 	hw = &slowck->hw;
 	ret = clk_hw_register(NULL, &slowck->hw);
 	if (ret) {
 		kfree(slowck);
 		hw = ERR_PTR(ret);
 	}

 	return hw;
 }

 static void __init at91sam9x5_sckc_register(struct device_node *np,
 					    unsigned int rc_osc_startup_us)
 {
 	const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
 	void __iomem *regbase = of_iomap(np, 0);
 	struct device_node *child = NULL;
 	const char *xtal_name;
 	struct clk_hw *hw;
 	bool bypass;

 	if (!regbase)
 		return;

 	hw = at91_clk_register_slow_rc_osc(regbase, parent_names[0], 32768,
 					   50000000, rc_osc_startup_us);
 	if (IS_ERR(hw))
 		return;

 	xtal_name = of_clk_get_parent_name(np, 0);
 	if (!xtal_name) {
 		/* DT backward compatibility */
 		child = of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow-osc");
 		if (!child)
 			return;

 		xtal_name = of_clk_get_parent_name(child, 0);
 		bypass = of_property_read_bool(child, "atmel,osc-bypass");

 		child =  of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow");
 	} else {
 		bypass = of_property_read_bool(np, "atmel,osc-bypass");
 	}

 	if (!xtal_name)
 		return;

 	hw = at91_clk_register_slow_osc(regbase, parent_names[1], xtal_name,
 					1200000, bypass);
 	if (IS_ERR(hw))
 		return;

 	hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
 	if (IS_ERR(hw))
 		return;

 	of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);

 	/* DT backward compatibility */
 	if (child)
 		of_clk_add_hw_provider(child, of_clk_hw_simple_get, hw);
 }

 static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
 {
 	at91sam9x5_sckc_register(np, 75);
 }
 CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
 	       of_at91sam9x5_sckc_setup);

 static void __init of_sama5d3_sckc_setup(struct device_node *np)
 {
 	at91sam9x5_sckc_register(np, 500);
 }
 CLK_OF_DECLARE(sama5d3_clk_sckc, "atmel,sama5d3-sckc",
 	       of_sama5d3_sckc_setup);

 static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
 {
 	struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);

 	if (osc->prepared)
 		return 0;

 	/*
 	 * Assume that if it has already been selected (for example by the
 	 * bootloader), enough time has aready passed.
 	 */
 	if ((readl(osc->sckcr) & AT91_SCKC_OSCSEL)) {
 		osc->prepared = true;
 		return 0;
 	}

 	usleep_range(osc->startup_usec, osc->startup_usec + 1);
 	osc->prepared = true;

 	return 0;
 }

 static int clk_sama5d4_slow_osc_is_prepared(struct clk_hw *hw)
 {
 	struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);

 	return osc->prepared;
 }

 static const struct clk_ops sama5d4_slow_osc_ops = {
 	.prepare = clk_sama5d4_slow_osc_prepare,
 	.is_prepared = clk_sama5d4_slow_osc_is_prepared,
 };

 static void __init of_sama5d4_sckc_setup(struct device_node *np)
 {
 	void __iomem *regbase = of_iomap(np, 0);
 	struct clk_hw *hw;
 	struct clk_sama5d4_slow_osc *osc;
 	struct clk_init_data init;
 	const char *xtal_name;
 	const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
 	bool bypass;
 	int ret;

 	if (!regbase)
 		return;

 	hw = clk_hw_register_fixed_rate_with_accuracy(NULL, parent_names[0],
 						      NULL, 0, 32768,
 						      250000000);
 	if (IS_ERR(hw))
 		return;

 	xtal_name = of_clk_get_parent_name(np, 0);

 	bypass = of_property_read_bool(np, "atmel,osc-bypass");

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

 	init.name = parent_names[1];
 	init.ops = &sama5d4_slow_osc_ops;
 	init.parent_names = &xtal_name;
 	init.num_parents = 1;
 	init.flags = CLK_IGNORE_UNUSED;

 	osc->hw.init = &init;
 	osc->sckcr = regbase;
 	osc->startup_usec = 1200000;

 	if (bypass)
 		writel((readl(regbase) | AT91_SCKC_OSC32BYP), regbase);

 	hw = &osc->hw;
 	ret = clk_hw_register(NULL, &osc->hw);
 	if (ret) {
 		kfree(osc);
 		return;
 	}

 	hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
 	if (IS_ERR(hw))
 		return;

 	of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
 }
 CLK_OF_DECLARE(sama5d4_clk_sckc, "atmel,sama5d4-sckc",
 	       of_sama5d4_sckc_setup);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* drivers/clk/at91/sckc.c
	*
	* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
	*/

	#include <linux/clk-provider.h>
	#include <linux/clkdev.h>
	#include <linux/delay.h>
	#include <linux/of.h>
	#include <linux/of_address.h>
	#include <linux/io.h>

	#define SLOW_CLOCK_FREQ 32768
	#define SLOWCK_SW_CYCLES 5
	#define SLOWCK_SW_TIME_USEC ((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
	SLOW_CLOCK_FREQ)

	#define AT91_SCKC_CR 0x00
	#define AT91_SCKC_RCEN (1 << 0)
	#define AT91_SCKC_OSC32EN (1 << 1)
	#define AT91_SCKC_OSC32BYP (1 << 2)
	#define AT91_SCKC_OSCSEL (1 << 3)

	struct clk_slow_osc {
	struct clk_hw hw;
	void __iomem *sckcr;
	unsigned long startup_usec;
	};

	#define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)

	struct clk_sama5d4_slow_osc {
	struct clk_hw hw;
	void __iomem *sckcr;
	unsigned long startup_usec;
	bool prepared;
	};

	#define to_clk_sama5d4_slow_osc(hw) container_of(hw, struct clk_sama5d4_slow_osc, hw)

	struct clk_slow_rc_osc {
	struct clk_hw hw;
	void __iomem *sckcr;
	unsigned long frequency;
	unsigned long accuracy;
	unsigned long startup_usec;
	};

	#define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)

	struct clk_sam9x5_slow {
	struct clk_hw hw;
	void __iomem *sckcr;
	u8 parent;
	};

	#define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)

	static int clk_slow_osc_prepare(struct clk_hw *hw)
	{
	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
	void __iomem *sckcr = osc->sckcr;
	u32 tmp = readl(sckcr);

	if (tmp & (AT91_SCKC_OSC32BYP \| AT91_SCKC_OSC32EN))
	return 0;

	writel(tmp \| AT91_SCKC_OSC32EN, sckcr);

	usleep_range(osc->startup_usec, osc->startup_usec + 1);

	return 0;
	}

	static void clk_slow_osc_unprepare(struct clk_hw *hw)
	{
	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
	void __iomem *sckcr = osc->sckcr;
	u32 tmp = readl(sckcr);

	if (tmp & AT91_SCKC_OSC32BYP)
	return;

	writel(tmp & ~AT91_SCKC_OSC32EN, sckcr);
	}

	static int clk_slow_osc_is_prepared(struct clk_hw *hw)
	{
	struct clk_slow_osc *osc = to_clk_slow_osc(hw);
	void __iomem *sckcr = osc->sckcr;
	u32 tmp = readl(sckcr);

	if (tmp & AT91_SCKC_OSC32BYP)
	return 1;

	return !!(tmp & AT91_SCKC_OSC32EN);
	}

	static const struct clk_ops slow_osc_ops = {
	.prepare = clk_slow_osc_prepare,
	.unprepare = clk_slow_osc_unprepare,
	.is_prepared = clk_slow_osc_is_prepared,
	};

	static struct clk_hw * __init
	at91_clk_register_slow_osc(void __iomem *sckcr,
	const char *name,
	const char *parent_name,
	unsigned long startup,
	bool bypass)
	{
	struct clk_slow_osc *osc;
	struct clk_hw *hw;
	struct clk_init_data init;
	int ret;

	if (!sckcr \|\| !name \|\| !parent_name)
	return ERR_PTR(-EINVAL);

	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
	if (!osc)
	return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &slow_osc_ops;
	init.parent_names = &parent_name;
	init.num_parents = 1;
	init.flags = CLK_IGNORE_UNUSED;

	osc->hw.init = &init;
	osc->sckcr = sckcr;
	osc->startup_usec = startup;

	if (bypass)
	writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) \| AT91_SCKC_OSC32BYP,
	sckcr);

	hw = &osc->hw;
	ret = clk_hw_register(NULL, &osc->hw);
	if (ret) {
	kfree(osc);
	hw = ERR_PTR(ret);
	}

	return hw;
	}

	static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);

	return osc->frequency;
	}

	static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
	unsigned long parent_acc)
	{
	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);

	return osc->accuracy;
	}

	static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
	{
	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
	void __iomem *sckcr = osc->sckcr;

	writel(readl(sckcr) \| AT91_SCKC_RCEN, sckcr);

	usleep_range(osc->startup_usec, osc->startup_usec + 1);

	return 0;
	}

	static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
	{
	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
	void __iomem *sckcr = osc->sckcr;

	writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr);
	}

	static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
	{
	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);

	return !!(readl(osc->sckcr) & AT91_SCKC_RCEN);
	}

	static const struct clk_ops slow_rc_osc_ops = {
	.prepare = clk_slow_rc_osc_prepare,
	.unprepare = clk_slow_rc_osc_unprepare,
	.is_prepared = clk_slow_rc_osc_is_prepared,
	.recalc_rate = clk_slow_rc_osc_recalc_rate,
	.recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
	};

	static struct clk_hw * __init
	at91_clk_register_slow_rc_osc(void __iomem *sckcr,
	const char *name,
	unsigned long frequency,
	unsigned long accuracy,
	unsigned long startup)
	{
	struct clk_slow_rc_osc *osc;
	struct clk_hw *hw;
	struct clk_init_data init;
	int ret;

	if (!sckcr \|\| !name)
	return ERR_PTR(-EINVAL);

	osc = kzalloc(sizeof(*osc), GFP_KERNEL);
	if (!osc)
	return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &slow_rc_osc_ops;
	init.parent_names = NULL;
	init.num_parents = 0;
	init.flags = CLK_IGNORE_UNUSED;

	osc->hw.init = &init;
	osc->sckcr = sckcr;
	osc->frequency = frequency;
	osc->accuracy = accuracy;
	osc->startup_usec = startup;

	hw = &osc->hw;
	ret = clk_hw_register(NULL, &osc->hw);
	if (ret) {
	kfree(osc);
	hw = ERR_PTR(ret);
	}

	return hw;
	}

	static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
	{
	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
	void __iomem *sckcr = slowck->sckcr;
	u32 tmp;

	if (index > 1)
	return -EINVAL;

	tmp = readl(sckcr);

	if ((!index && !(tmp & AT91_SCKC_OSCSEL)) \|\|
	(index && (tmp & AT91_SCKC_OSCSEL)))
	return 0;

	if (index)
	tmp \|= AT91_SCKC_OSCSEL;
	else
	tmp &= ~AT91_SCKC_OSCSEL;

	writel(tmp, sckcr);

	usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);

	return 0;
	}

	static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
	{
	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);

	return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL);
	}

	static const struct clk_ops sam9x5_slow_ops = {
	.set_parent = clk_sam9x5_slow_set_parent,
	.get_parent = clk_sam9x5_slow_get_parent,
	};

	static struct clk_hw * __init
	at91_clk_register_sam9x5_slow(void __iomem *sckcr,
	const char *name,
	const char **parent_names,
	int num_parents)
	{
	struct clk_sam9x5_slow *slowck;
	struct clk_hw *hw;
	struct clk_init_data init;
	int ret;

	if (!sckcr \|\| !name \|\| !parent_names \|\| !num_parents)
	return ERR_PTR(-EINVAL);

	slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
	if (!slowck)
	return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &sam9x5_slow_ops;
	init.parent_names = parent_names;
	init.num_parents = num_parents;
	init.flags = 0;

	slowck->hw.init = &init;
	slowck->sckcr = sckcr;
	slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL);

	hw = &slowck->hw;
	ret = clk_hw_register(NULL, &slowck->hw);
	if (ret) {
	kfree(slowck);
	hw = ERR_PTR(ret);
	}

	return hw;
	}

	static void __init at91sam9x5_sckc_register(struct device_node *np,
	unsigned int rc_osc_startup_us)
	{
	const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
	void __iomem *regbase = of_iomap(np, 0);
	struct device_node *child = NULL;
	const char *xtal_name;
	struct clk_hw *hw;
	bool bypass;

	if (!regbase)
	return;

	hw = at91_clk_register_slow_rc_osc(regbase, parent_names[0], 32768,
	50000000, rc_osc_startup_us);
	if (IS_ERR(hw))
	return;

	xtal_name = of_clk_get_parent_name(np, 0);
	if (!xtal_name) {
	/* DT backward compatibility */
	child = of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow-osc");
	if (!child)
	return;

	xtal_name = of_clk_get_parent_name(child, 0);
	bypass = of_property_read_bool(child, "atmel,osc-bypass");

	child = of_get_compatible_child(np, "atmel,at91sam9x5-clk-slow");
	} else {
	bypass = of_property_read_bool(np, "atmel,osc-bypass");
	}

	if (!xtal_name)
	return;

	hw = at91_clk_register_slow_osc(regbase, parent_names[1], xtal_name,
	1200000, bypass);
	if (IS_ERR(hw))
	return;

	hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
	if (IS_ERR(hw))
	return;

	of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);

	/* DT backward compatibility */
	if (child)
	of_clk_add_hw_provider(child, of_clk_hw_simple_get, hw);
	}

	static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
	{
	at91sam9x5_sckc_register(np, 75);
	}
	CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
	of_at91sam9x5_sckc_setup);

	static void __init of_sama5d3_sckc_setup(struct device_node *np)
	{
	at91sam9x5_sckc_register(np, 500);
	}
	CLK_OF_DECLARE(sama5d3_clk_sckc, "atmel,sama5d3-sckc",
	of_sama5d3_sckc_setup);

	static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
	{
	struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);

	if (osc->prepared)
	return 0;

	/*
	* Assume that if it has already been selected (for example by the
	* bootloader), enough time has aready passed.
	*/
	if ((readl(osc->sckcr) & AT91_SCKC_OSCSEL)) {
	osc->prepared = true;
	return 0;
	}

	usleep_range(osc->startup_usec, osc->startup_usec + 1);
	osc->prepared = true;

	return 0;
	}

	static int clk_sama5d4_slow_osc_is_prepared(struct clk_hw *hw)
	{
	struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);

	return osc->prepared;
	}

	static const struct clk_ops sama5d4_slow_osc_ops = {
	.prepare = clk_sama5d4_slow_osc_prepare,
	.is_prepared = clk_sama5d4_slow_osc_is_prepared,
	};

	static void __init of_sama5d4_sckc_setup(struct device_node *np)
	{
	void __iomem *regbase = of_iomap(np, 0);
	struct clk_hw *hw;
	struct clk_sama5d4_slow_osc *osc;
	struct clk_init_data init;
	const char *xtal_name;
	const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
	bool bypass;
	int ret;

	if (!regbase)
	return;

	hw = clk_hw_register_fixed_rate_with_accuracy(NULL, parent_names[0],
	NULL, 0, 32768,
	250000000);
	if (IS_ERR(hw))
	return;

	xtal_name = of_clk_get_parent_name(np, 0);

	bypass = of_property_read_bool(np, "atmel,osc-bypass");

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

	init.name = parent_names[1];
	init.ops = &sama5d4_slow_osc_ops;
	init.parent_names = &xtal_name;
	init.num_parents = 1;
	init.flags = CLK_IGNORE_UNUSED;

	osc->hw.init = &init;
	osc->sckcr = regbase;
	osc->startup_usec = 1200000;

	if (bypass)
	writel((readl(regbase) \| AT91_SCKC_OSC32BYP), regbase);

	hw = &osc->hw;
	ret = clk_hw_register(NULL, &osc->hw);
	if (ret) {
	kfree(osc);
	return;
	}

	hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
	if (IS_ERR(hw))
	return;

	of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
	}
	CLK_OF_DECLARE(sama5d4_clk_sckc, "atmel,sama5d4-sckc",
	of_sama5d4_sckc_setup);