| // SPDX-License-Identifier: GPL-2.0 | 
 | /* | 
 |  * MVEBU Core divider clock | 
 |  * | 
 |  * Copyright (C) 2013 Marvell | 
 |  * | 
 |  * Ezequiel Garcia <ezequiel.garcia@free-electrons.com> | 
 |  * | 
 |  */ | 
 |  | 
 | #include <linux/kernel.h> | 
 | #include <linux/clk-provider.h> | 
 | #include <linux/io.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 = 27 }, /* 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); |