drivers/clk/mvebu/clk-corediv.c - arm/linux - Git at Google

 /*
  * MVEBU Core divider clock
  *
  * Copyright (C) 2013 Marvell
  *
  * Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
  *
  * This file is licensed under the terms of the GNU General Public
  * License version 2.  This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
  */

 #include <linux/kernel.h>
 #include <linux/clk-provider.h>
 #include <linux/of_address.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include "common.h"

 #define CORE_CLK_DIV_RATIO_MASK		0xff

 /*
  * This structure describes the hardware details (bit offset and mask)
  * to configure one particular core divider clock. Those hardware
  * details may differ from one SoC to another. This structure is
  * therefore typically instantiated statically to describe the
  * hardware details.
  */
 struct clk_corediv_desc {
 	unsigned int mask;
 	unsigned int offset;
 	unsigned int fieldbit;
 };

 /*
  * This structure describes the hardware details to configure the core
  * divider clocks on a given SoC. Amongst others, it points to the
  * array of core divider clock descriptors for this SoC, as well as
  * the corresponding operations to manipulate them.
  */
 struct clk_corediv_soc_desc {
 	const struct clk_corediv_desc *descs;
 	unsigned int ndescs;
 	const struct clk_ops ops;
 	u32 ratio_reload;
 	u32 enable_bit_offset;
 	u32 ratio_offset;
 };

 /*
  * This structure represents one core divider clock for the clock
  * framework, and is dynamically allocated for each core divider clock
  * existing in the current SoC.
  */
 struct clk_corediv {
 	struct clk_hw hw;
 	void __iomem *reg;
 	const struct clk_corediv_desc *desc;
 	const struct clk_corediv_soc_desc *soc_desc;
 	spinlock_t lock;
 };

 static struct clk_onecell_data clk_data;

 /*
  * Description of the core divider clocks available. For now, we
  * support only NAND, and it is available at the same register
  * locations regardless of the SoC.
  */
 static const struct clk_corediv_desc mvebu_corediv_desc[] = {
 	{ .mask = 0x3f, .offset = 8, .fieldbit = 1 }, /* NAND clock */
 };

 static const struct clk_corediv_desc mv98dx3236_corediv_desc[] = {
 	{ .mask = 0x0f, .offset = 6, .fieldbit = 26 }, /* NAND clock */
 };

 #define to_corediv_clk(p) container_of(p, struct clk_corediv, hw)

 static int clk_corediv_is_enabled(struct clk_hw *hwclk)
 {
 	struct clk_corediv *corediv = to_corediv_clk(hwclk);
 	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
 	const struct clk_corediv_desc *desc = corediv->desc;
 	u32 enable_mask = BIT(desc->fieldbit) << soc_desc->enable_bit_offset;

 	return !!(readl(corediv->reg) & enable_mask);
 }

 static int clk_corediv_enable(struct clk_hw *hwclk)
 {
 	struct clk_corediv *corediv = to_corediv_clk(hwclk);
 	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
 	const struct clk_corediv_desc *desc = corediv->desc;
 	unsigned long flags = 0;
 	u32 reg;

 	spin_lock_irqsave(&corediv->lock, flags);

 	reg = readl(corediv->reg);
 	reg |= (BIT(desc->fieldbit) << soc_desc->enable_bit_offset);
 	writel(reg, corediv->reg);

 	spin_unlock_irqrestore(&corediv->lock, flags);

 	return 0;
 }

 static void clk_corediv_disable(struct clk_hw *hwclk)
 {
 	struct clk_corediv *corediv = to_corediv_clk(hwclk);
 	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
 	const struct clk_corediv_desc *desc = corediv->desc;
 	unsigned long flags = 0;
 	u32 reg;

 	spin_lock_irqsave(&corediv->lock, flags);

 	reg = readl(corediv->reg);
 	reg &= ~(BIT(desc->fieldbit) << soc_desc->enable_bit_offset);
 	writel(reg, corediv->reg);

 	spin_unlock_irqrestore(&corediv->lock, flags);
 }

 static unsigned long clk_corediv_recalc_rate(struct clk_hw *hwclk,
 					 unsigned long parent_rate)
 {
 	struct clk_corediv *corediv = to_corediv_clk(hwclk);
 	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
 	const struct clk_corediv_desc *desc = corediv->desc;
 	u32 reg, div;

 	reg = readl(corediv->reg + soc_desc->ratio_offset);
 	div = (reg >> desc->offset) & desc->mask;
 	return parent_rate / div;
 }

 static long clk_corediv_round_rate(struct clk_hw *hwclk, unsigned long rate,
 			       unsigned long *parent_rate)
 {
 	/* Valid ratio are 1:4, 1:5, 1:6 and 1:8 */
 	u32 div;

 	div = *parent_rate / rate;
 	if (div < 4)
 		div = 4;
 	else if (div > 6)
 		div = 8;

 	return *parent_rate / div;
 }

 static int clk_corediv_set_rate(struct clk_hw *hwclk, unsigned long rate,
 			    unsigned long parent_rate)
 {
 	struct clk_corediv *corediv = to_corediv_clk(hwclk);
 	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
 	const struct clk_corediv_desc *desc = corediv->desc;
 	unsigned long flags = 0;
 	u32 reg, div;

 	div = parent_rate / rate;

 	spin_lock_irqsave(&corediv->lock, flags);

 	/* Write new divider to the divider ratio register */
 	reg = readl(corediv->reg + soc_desc->ratio_offset);
 	reg &= ~(desc->mask << desc->offset);
 	reg |= (div & desc->mask) << desc->offset;
 	writel(reg, corediv->reg + soc_desc->ratio_offset);

 	/* Set reload-force for this clock */
 	reg = readl(corediv->reg) | BIT(desc->fieldbit);
 	writel(reg, corediv->reg);

 	/* Now trigger the clock update */
 	reg = readl(corediv->reg) | soc_desc->ratio_reload;
 	writel(reg, corediv->reg);

 	/*
 	 * Wait for clocks to settle down, and then clear all the
 	 * ratios request and the reload request.
 	 */
 	udelay(1000);
 	reg &= ~(CORE_CLK_DIV_RATIO_MASK | soc_desc->ratio_reload);
 	writel(reg, corediv->reg);
 	udelay(1000);

 	spin_unlock_irqrestore(&corediv->lock, flags);

 	return 0;
 }

 static const struct clk_corediv_soc_desc armada370_corediv_soc = {
 	.descs = mvebu_corediv_desc,
 	.ndescs = ARRAY_SIZE(mvebu_corediv_desc),
 	.ops = {
 		.enable = clk_corediv_enable,
 		.disable = clk_corediv_disable,
 		.is_enabled = clk_corediv_is_enabled,
 		.recalc_rate = clk_corediv_recalc_rate,
 		.round_rate = clk_corediv_round_rate,
 		.set_rate = clk_corediv_set_rate,
 	},
 	.ratio_reload = BIT(8),
 	.enable_bit_offset = 24,
 	.ratio_offset = 0x8,
 };

 static const struct clk_corediv_soc_desc armada380_corediv_soc = {
 	.descs = mvebu_corediv_desc,
 	.ndescs = ARRAY_SIZE(mvebu_corediv_desc),
 	.ops = {
 		.enable = clk_corediv_enable,
 		.disable = clk_corediv_disable,
 		.is_enabled = clk_corediv_is_enabled,
 		.recalc_rate = clk_corediv_recalc_rate,
 		.round_rate = clk_corediv_round_rate,
 		.set_rate = clk_corediv_set_rate,
 	},
 	.ratio_reload = BIT(8),
 	.enable_bit_offset = 16,
 	.ratio_offset = 0x4,
 };

 static const struct clk_corediv_soc_desc armada375_corediv_soc = {
 	.descs = mvebu_corediv_desc,
 	.ndescs = ARRAY_SIZE(mvebu_corediv_desc),
 	.ops = {
 		.recalc_rate = clk_corediv_recalc_rate,
 		.round_rate = clk_corediv_round_rate,
 		.set_rate = clk_corediv_set_rate,
 	},
 	.ratio_reload = BIT(8),
 	.ratio_offset = 0x4,
 };

 static const struct clk_corediv_soc_desc mv98dx3236_corediv_soc = {
 	.descs = mv98dx3236_corediv_desc,
 	.ndescs = ARRAY_SIZE(mv98dx3236_corediv_desc),
 	.ops = {
 		.recalc_rate = clk_corediv_recalc_rate,
 		.round_rate = clk_corediv_round_rate,
 		.set_rate = clk_corediv_set_rate,
 	},
 	.ratio_reload = BIT(10),
 	.ratio_offset = 0x8,
 };

 static void __init
 mvebu_corediv_clk_init(struct device_node *node,
 		       const struct clk_corediv_soc_desc *soc_desc)
 {
 	struct clk_init_data init;
 	struct clk_corediv *corediv;
 	struct clk **clks;
 	void __iomem *base;
 	const char *parent_name;
 	const char *clk_name;
 	int i;

 	base = of_iomap(node, 0);
 	if (WARN_ON(!base))
 		return;

 	parent_name = of_clk_get_parent_name(node, 0);

 	clk_data.clk_num = soc_desc->ndescs;

 	/* clks holds the clock array */
 	clks = kcalloc(clk_data.clk_num, sizeof(struct clk *),
 				GFP_KERNEL);
 	if (WARN_ON(!clks))
 		goto err_unmap;
 	/* corediv holds the clock specific array */
 	corediv = kcalloc(clk_data.clk_num, sizeof(struct clk_corediv),
 				GFP_KERNEL);
 	if (WARN_ON(!corediv))
 		goto err_free_clks;

 	spin_lock_init(&corediv->lock);

 	for (i = 0; i < clk_data.clk_num; i++) {
 		of_property_read_string_index(node, "clock-output-names",
 					      i, &clk_name);
 		init.num_parents = 1;
 		init.parent_names = &parent_name;
 		init.name = clk_name;
 		init.ops = &soc_desc->ops;
 		init.flags = 0;

 		corediv[i].soc_desc = soc_desc;
 		corediv[i].desc = soc_desc->descs + i;
 		corediv[i].reg = base;
 		corediv[i].hw.init = &init;

 		clks[i] = clk_register(NULL, &corediv[i].hw);
 		WARN_ON(IS_ERR(clks[i]));
 	}

 	clk_data.clks = clks;
 	of_clk_add_provider(node, of_clk_src_onecell_get, &clk_data);
 	return;

 err_free_clks:
 	kfree(clks);
 err_unmap:
 	iounmap(base);
 }

 static void __init armada370_corediv_clk_init(struct device_node *node)
 {
 	return mvebu_corediv_clk_init(node, &armada370_corediv_soc);
 }
 CLK_OF_DECLARE(armada370_corediv_clk, "marvell,armada-370-corediv-clock",
 	       armada370_corediv_clk_init);

 static void __init armada375_corediv_clk_init(struct device_node *node)
 {
 	return mvebu_corediv_clk_init(node, &armada375_corediv_soc);
 }
 CLK_OF_DECLARE(armada375_corediv_clk, "marvell,armada-375-corediv-clock",
 	       armada375_corediv_clk_init);

 static void __init armada380_corediv_clk_init(struct device_node *node)
 {
 	return mvebu_corediv_clk_init(node, &armada380_corediv_soc);
 }
 CLK_OF_DECLARE(armada380_corediv_clk, "marvell,armada-380-corediv-clock",
 	       armada380_corediv_clk_init);

 static void __init mv98dx3236_corediv_clk_init(struct device_node *node)
 {
 	return mvebu_corediv_clk_init(node, &mv98dx3236_corediv_soc);
 }
 CLK_OF_DECLARE(mv98dx3236_corediv_clk, "marvell,mv98dx3236-corediv-clock",
 	       mv98dx3236_corediv_clk_init);
	/*
	* MVEBU Core divider clock
	*
	* Copyright (C) 2013 Marvell
	*
	* Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
	*
	* This file is licensed under the terms of the GNU General Public
	* License version 2. This program is licensed "as is" without any
	* warranty of any kind, whether express or implied.
	*/

	#include <linux/kernel.h>
	#include <linux/clk-provider.h>
	#include <linux/of_address.h>
	#include <linux/slab.h>
	#include <linux/delay.h>
	#include "common.h"

	#define CORE_CLK_DIV_RATIO_MASK 0xff

	/*
	* This structure describes the hardware details (bit offset and mask)
	* to configure one particular core divider clock. Those hardware
	* details may differ from one SoC to another. This structure is
	* therefore typically instantiated statically to describe the
	* hardware details.
	*/
	struct clk_corediv_desc {
	unsigned int mask;
	unsigned int offset;
	unsigned int fieldbit;
	};

	/*
	* This structure describes the hardware details to configure the core
	* divider clocks on a given SoC. Amongst others, it points to the
	* array of core divider clock descriptors for this SoC, as well as
	* the corresponding operations to manipulate them.
	*/
	struct clk_corediv_soc_desc {
	const struct clk_corediv_desc *descs;
	unsigned int ndescs;
	const struct clk_ops ops;
	u32 ratio_reload;
	u32 enable_bit_offset;
	u32 ratio_offset;
	};

	/*
	* This structure represents one core divider clock for the clock
	* framework, and is dynamically allocated for each core divider clock
	* existing in the current SoC.
	*/
	struct clk_corediv {
	struct clk_hw hw;
	void __iomem *reg;
	const struct clk_corediv_desc *desc;
	const struct clk_corediv_soc_desc *soc_desc;
	spinlock_t lock;
	};

	static struct clk_onecell_data clk_data;

	/*
	* Description of the core divider clocks available. For now, we
	* support only NAND, and it is available at the same register
	* locations regardless of the SoC.
	*/
	static const struct clk_corediv_desc mvebu_corediv_desc[] = {
	{ .mask = 0x3f, .offset = 8, .fieldbit = 1 }, /* NAND clock */
	};

	static const struct clk_corediv_desc mv98dx3236_corediv_desc[] = {
	{ .mask = 0x0f, .offset = 6, .fieldbit = 26 }, /* NAND clock */
	};

	#define to_corediv_clk(p) container_of(p, struct clk_corediv, hw)

	static int clk_corediv_is_enabled(struct clk_hw *hwclk)
	{
	struct clk_corediv *corediv = to_corediv_clk(hwclk);
	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
	const struct clk_corediv_desc *desc = corediv->desc;
	u32 enable_mask = BIT(desc->fieldbit) << soc_desc->enable_bit_offset;

	return !!(readl(corediv->reg) & enable_mask);
	}

	static int clk_corediv_enable(struct clk_hw *hwclk)
	{
	struct clk_corediv *corediv = to_corediv_clk(hwclk);
	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
	const struct clk_corediv_desc *desc = corediv->desc;
	unsigned long flags = 0;
	u32 reg;

	spin_lock_irqsave(&corediv->lock, flags);

	reg = readl(corediv->reg);
	reg \|= (BIT(desc->fieldbit) << soc_desc->enable_bit_offset);
	writel(reg, corediv->reg);

	spin_unlock_irqrestore(&corediv->lock, flags);

	return 0;
	}

	static void clk_corediv_disable(struct clk_hw *hwclk)
	{
	struct clk_corediv *corediv = to_corediv_clk(hwclk);
	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
	const struct clk_corediv_desc *desc = corediv->desc;
	unsigned long flags = 0;
	u32 reg;

	spin_lock_irqsave(&corediv->lock, flags);

	reg = readl(corediv->reg);
	reg &= ~(BIT(desc->fieldbit) << soc_desc->enable_bit_offset);
	writel(reg, corediv->reg);

	spin_unlock_irqrestore(&corediv->lock, flags);
	}

	static unsigned long clk_corediv_recalc_rate(struct clk_hw *hwclk,
	unsigned long parent_rate)
	{
	struct clk_corediv *corediv = to_corediv_clk(hwclk);
	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
	const struct clk_corediv_desc *desc = corediv->desc;
	u32 reg, div;

	reg = readl(corediv->reg + soc_desc->ratio_offset);
	div = (reg >> desc->offset) & desc->mask;
	return parent_rate / div;
	}

	static long clk_corediv_round_rate(struct clk_hw *hwclk, unsigned long rate,
	unsigned long *parent_rate)
	{
	/* Valid ratio are 1:4, 1:5, 1:6 and 1:8 */
	u32 div;

	div = *parent_rate / rate;
	if (div < 4)
	div = 4;
	else if (div > 6)
	div = 8;

	return *parent_rate / div;
	}

	static int clk_corediv_set_rate(struct clk_hw *hwclk, unsigned long rate,
	unsigned long parent_rate)
	{
	struct clk_corediv *corediv = to_corediv_clk(hwclk);
	const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
	const struct clk_corediv_desc *desc = corediv->desc;
	unsigned long flags = 0;
	u32 reg, div;

	div = parent_rate / rate;

	spin_lock_irqsave(&corediv->lock, flags);

	/* Write new divider to the divider ratio register */
	reg = readl(corediv->reg + soc_desc->ratio_offset);
	reg &= ~(desc->mask << desc->offset);
	reg \|= (div & desc->mask) << desc->offset;
	writel(reg, corediv->reg + soc_desc->ratio_offset);

	/* Set reload-force for this clock */
	reg = readl(corediv->reg) \| BIT(desc->fieldbit);
	writel(reg, corediv->reg);

	/* Now trigger the clock update */
	reg = readl(corediv->reg) \| soc_desc->ratio_reload;
	writel(reg, corediv->reg);

	/*
	* Wait for clocks to settle down, and then clear all the
	* ratios request and the reload request.
	*/
	udelay(1000);
	reg &= ~(CORE_CLK_DIV_RATIO_MASK \| soc_desc->ratio_reload);
	writel(reg, corediv->reg);
	udelay(1000);

	spin_unlock_irqrestore(&corediv->lock, flags);

	return 0;
	}

	static const struct clk_corediv_soc_desc armada370_corediv_soc = {
	.descs = mvebu_corediv_desc,
	.ndescs = ARRAY_SIZE(mvebu_corediv_desc),
	.ops = {
	.enable = clk_corediv_enable,
	.disable = clk_corediv_disable,
	.is_enabled = clk_corediv_is_enabled,
	.recalc_rate = clk_corediv_recalc_rate,
	.round_rate = clk_corediv_round_rate,
	.set_rate = clk_corediv_set_rate,
	},
	.ratio_reload = BIT(8),
	.enable_bit_offset = 24,
	.ratio_offset = 0x8,
	};

	static const struct clk_corediv_soc_desc armada380_corediv_soc = {
	.descs = mvebu_corediv_desc,
	.ndescs = ARRAY_SIZE(mvebu_corediv_desc),
	.ops = {
	.enable = clk_corediv_enable,
	.disable = clk_corediv_disable,
	.is_enabled = clk_corediv_is_enabled,
	.recalc_rate = clk_corediv_recalc_rate,
	.round_rate = clk_corediv_round_rate,
	.set_rate = clk_corediv_set_rate,
	},
	.ratio_reload = BIT(8),
	.enable_bit_offset = 16,
	.ratio_offset = 0x4,
	};

	static const struct clk_corediv_soc_desc armada375_corediv_soc = {
	.descs = mvebu_corediv_desc,
	.ndescs = ARRAY_SIZE(mvebu_corediv_desc),
	.ops = {
	.recalc_rate = clk_corediv_recalc_rate,
	.round_rate = clk_corediv_round_rate,
	.set_rate = clk_corediv_set_rate,
	},
	.ratio_reload = BIT(8),
	.ratio_offset = 0x4,
	};

	static const struct clk_corediv_soc_desc mv98dx3236_corediv_soc = {
	.descs = mv98dx3236_corediv_desc,
	.ndescs = ARRAY_SIZE(mv98dx3236_corediv_desc),
	.ops = {
	.recalc_rate = clk_corediv_recalc_rate,
	.round_rate = clk_corediv_round_rate,
	.set_rate = clk_corediv_set_rate,
	},
	.ratio_reload = BIT(10),
	.ratio_offset = 0x8,
	};

	static void __init
	mvebu_corediv_clk_init(struct device_node *node,
	const struct clk_corediv_soc_desc *soc_desc)
	{
	struct clk_init_data init;
	struct clk_corediv *corediv;
	struct clk **clks;
	void __iomem *base;
	const char *parent_name;
	const char *clk_name;
	int i;

	base = of_iomap(node, 0);
	if (WARN_ON(!base))
	return;

	parent_name = of_clk_get_parent_name(node, 0);

	clk_data.clk_num = soc_desc->ndescs;

	/* clks holds the clock array */
	clks = kcalloc(clk_data.clk_num, sizeof(struct clk *),
	GFP_KERNEL);
	if (WARN_ON(!clks))
	goto err_unmap;
	/* corediv holds the clock specific array */
	corediv = kcalloc(clk_data.clk_num, sizeof(struct clk_corediv),
	GFP_KERNEL);
	if (WARN_ON(!corediv))
	goto err_free_clks;

	spin_lock_init(&corediv->lock);

	for (i = 0; i < clk_data.clk_num; i++) {
	of_property_read_string_index(node, "clock-output-names",
	i, &clk_name);
	init.num_parents = 1;
	init.parent_names = &parent_name;
	init.name = clk_name;
	init.ops = &soc_desc->ops;
	init.flags = 0;

	corediv[i].soc_desc = soc_desc;
	corediv[i].desc = soc_desc->descs + i;
	corediv[i].reg = base;
	corediv[i].hw.init = &init;

	clks[i] = clk_register(NULL, &corediv[i].hw);
	WARN_ON(IS_ERR(clks[i]));
	}

	clk_data.clks = clks;
	of_clk_add_provider(node, of_clk_src_onecell_get, &clk_data);
	return;

	err_free_clks:
	kfree(clks);
	err_unmap:
	iounmap(base);
	}

	static void __init armada370_corediv_clk_init(struct device_node *node)
	{
	return mvebu_corediv_clk_init(node, &armada370_corediv_soc);
	}
	CLK_OF_DECLARE(armada370_corediv_clk, "marvell,armada-370-corediv-clock",
	armada370_corediv_clk_init);

	static void __init armada375_corediv_clk_init(struct device_node *node)
	{
	return mvebu_corediv_clk_init(node, &armada375_corediv_soc);
	}
	CLK_OF_DECLARE(armada375_corediv_clk, "marvell,armada-375-corediv-clock",
	armada375_corediv_clk_init);

	static void __init armada380_corediv_clk_init(struct device_node *node)
	{
	return mvebu_corediv_clk_init(node, &armada380_corediv_soc);
	}
	CLK_OF_DECLARE(armada380_corediv_clk, "marvell,armada-380-corediv-clock",
	armada380_corediv_clk_init);

	static void __init mv98dx3236_corediv_clk_init(struct device_node *node)
	{
	return mvebu_corediv_clk_init(node, &mv98dx3236_corediv_soc);
	}
	CLK_OF_DECLARE(mv98dx3236_corediv_clk, "marvell,mv98dx3236-corediv-clock",
	mv98dx3236_corediv_clk_init);