drivers/clk/shmobile/clk-rcar-gen2.c - linux - Git at Google

 /*
  * rcar_gen2 Core CPG Clocks
  *
  * Copyright (C) 2013  Ideas On Board SPRL
  *
  * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.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; version 2 of the License.
  */

 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
 #include <linux/clk/shmobile.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/math64.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/spinlock.h>

 struct rcar_gen2_cpg {
 	struct clk_onecell_data data;
 	spinlock_t lock;
 	void __iomem *reg;
 };

 #define CPG_FRQCRB			0x00000004
 #define CPG_FRQCRB_KICK			BIT(31)
 #define CPG_SDCKCR			0x00000074
 #define CPG_PLL0CR			0x000000d8
 #define CPG_FRQCRC			0x000000e0
 #define CPG_FRQCRC_ZFC_MASK		(0x1f << 8)
 #define CPG_FRQCRC_ZFC_SHIFT		8

 /* -----------------------------------------------------------------------------
  * Z Clock
  *
  * Traits of this clock:
  * prepare - clk_prepare only ensures that parents are prepared
  * enable - clk_enable only ensures that parents are enabled
  * rate - rate is adjustable.  clk->rate = parent->rate * mult / 32
  * parent - fixed parent.  No clk_set_parent support
  */

 struct cpg_z_clk {
 	struct clk_hw hw;
 	void __iomem *reg;
 	void __iomem *kick_reg;
 };

 #define to_z_clk(_hw)	container_of(_hw, struct cpg_z_clk, hw)

 static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw,
 					   unsigned long parent_rate)
 {
 	struct cpg_z_clk *zclk = to_z_clk(hw);
 	unsigned int mult;
 	unsigned int val;

 	val = (clk_readl(zclk->reg) & CPG_FRQCRC_ZFC_MASK)
 	    >> CPG_FRQCRC_ZFC_SHIFT;
 	mult = 32 - val;

 	return div_u64((u64)parent_rate * mult, 32);
 }

 static long cpg_z_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 				 unsigned long *parent_rate)
 {
 	unsigned long prate  = *parent_rate;
 	unsigned int mult;

 	if (!prate)
 		prate = 1;

 	mult = div_u64((u64)rate * 32, prate);
 	mult = clamp(mult, 1U, 32U);

 	return *parent_rate / 32 * mult;
 }

 static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 			      unsigned long parent_rate)
 {
 	struct cpg_z_clk *zclk = to_z_clk(hw);
 	unsigned int mult;
 	u32 val, kick;
 	unsigned int i;

 	mult = div_u64((u64)rate * 32, parent_rate);
 	mult = clamp(mult, 1U, 32U);

 	if (clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK)
 		return -EBUSY;

 	val = clk_readl(zclk->reg);
 	val &= ~CPG_FRQCRC_ZFC_MASK;
 	val |= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT;
 	clk_writel(val, zclk->reg);

 	/*
 	 * Set KICK bit in FRQCRB to update hardware setting and wait for
 	 * clock change completion.
 	 */
 	kick = clk_readl(zclk->kick_reg);
 	kick |= CPG_FRQCRB_KICK;
 	clk_writel(kick, zclk->kick_reg);

 	/*
 	 * Note: There is no HW information about the worst case latency.
 	 *
 	 * Using experimental measurements, it seems that no more than
 	 * ~10 iterations are needed, independently of the CPU rate.
 	 * Since this value might be dependant of external xtal rate, pll1
 	 * rate or even the other emulation clocks rate, use 1000 as a
 	 * "super" safe value.
 	 */
 	for (i = 1000; i; i--) {
 		if (!(clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK))
 			return 0;

 		cpu_relax();
 	}

 	return -ETIMEDOUT;
 }

 static const struct clk_ops cpg_z_clk_ops = {
 	.recalc_rate = cpg_z_clk_recalc_rate,
 	.round_rate = cpg_z_clk_round_rate,
 	.set_rate = cpg_z_clk_set_rate,
 };

 static struct clk * __init cpg_z_clk_register(struct rcar_gen2_cpg *cpg)
 {
 	static const char *parent_name = "pll0";
 	struct clk_init_data init;
 	struct cpg_z_clk *zclk;
 	struct clk *clk;

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

 	init.name = "z";
 	init.ops = &cpg_z_clk_ops;
 	init.flags = 0;
 	init.parent_names = &parent_name;
 	init.num_parents = 1;

 	zclk->reg = cpg->reg + CPG_FRQCRC;
 	zclk->kick_reg = cpg->reg + CPG_FRQCRB;
 	zclk->hw.init = &init;

 	clk = clk_register(NULL, &zclk->hw);
 	if (IS_ERR(clk))
 		kfree(zclk);

 	return clk;
 }

 /* -----------------------------------------------------------------------------
  * CPG Clock Data
  */

 /*
  *   MD		EXTAL		PLL0	PLL1	PLL3
  * 14 13 19	(MHz)		*1	*1
  *---------------------------------------------------
  * 0  0  0	15 x 1		x172/2	x208/2	x106
  * 0  0  1	15 x 1		x172/2	x208/2	x88
  * 0  1  0	20 x 1		x130/2	x156/2	x80
  * 0  1  1	20 x 1		x130/2	x156/2	x66
  * 1  0  0	26 / 2		x200/2	x240/2	x122
  * 1  0  1	26 / 2		x200/2	x240/2	x102
  * 1  1  0	30 / 2		x172/2	x208/2	x106
  * 1  1  1	30 / 2		x172/2	x208/2	x88
  *
  * *1 :	Table 7.6 indicates VCO ouput (PLLx = VCO/2)
  */
 #define CPG_PLL_CONFIG_INDEX(md)	((((md) & BIT(14)) >> 12) | \
 					 (((md) & BIT(13)) >> 12) | \
 					 (((md) & BIT(19)) >> 19))
 struct cpg_pll_config {
 	unsigned int extal_div;
 	unsigned int pll1_mult;
 	unsigned int pll3_mult;
 };

 static const struct cpg_pll_config cpg_pll_configs[8] __initconst = {
 	{ 1, 208, 106 }, { 1, 208,  88 }, { 1, 156,  80 }, { 1, 156,  66 },
 	{ 2, 240, 122 }, { 2, 240, 102 }, { 2, 208, 106 }, { 2, 208,  88 },
 };

 /* SDHI divisors */
 static const struct clk_div_table cpg_sdh_div_table[] = {
 	{  0,  2 }, {  1,  3 }, {  2,  4 }, {  3,  6 },
 	{  4,  8 }, {  5, 12 }, {  6, 16 }, {  7, 18 },
 	{  8, 24 }, { 10, 36 }, { 11, 48 }, {  0,  0 },
 };

 static const struct clk_div_table cpg_sd01_div_table[] = {
 	{  4,  8 },
 	{  5, 12 }, {  6, 16 }, {  7, 18 }, {  8, 24 },
 	{ 10, 36 }, { 11, 48 }, { 12, 10 }, {  0,  0 },
 };

 /* -----------------------------------------------------------------------------
  * Initialization
  */

 static u32 cpg_mode __initdata;

 static struct clk * __init
 rcar_gen2_cpg_register_clock(struct device_node *np, struct rcar_gen2_cpg *cpg,
 			     const struct cpg_pll_config *config,
 			     const char *name)
 {
 	const struct clk_div_table *table = NULL;
 	const char *parent_name;
 	unsigned int shift;
 	unsigned int mult = 1;
 	unsigned int div = 1;

 	if (!strcmp(name, "main")) {
 		parent_name = of_clk_get_parent_name(np, 0);
 		div = config->extal_div;
 	} else if (!strcmp(name, "pll0")) {
 		/* PLL0 is a configurable multiplier clock. Register it as a
 		 * fixed factor clock for now as there's no generic multiplier
 		 * clock implementation and we currently have no need to change
 		 * the multiplier value.
 		 */
 		u32 value = clk_readl(cpg->reg + CPG_PLL0CR);
 		parent_name = "main";
 		mult = ((value >> 24) & ((1 << 7) - 1)) + 1;
 	} else if (!strcmp(name, "pll1")) {
 		parent_name = "main";
 		mult = config->pll1_mult / 2;
 	} else if (!strcmp(name, "pll3")) {
 		parent_name = "main";
 		mult = config->pll3_mult;
 	} else if (!strcmp(name, "lb")) {
 		parent_name = "pll1";
 		div = cpg_mode & BIT(18) ? 36 : 24;
 	} else if (!strcmp(name, "qspi")) {
 		parent_name = "pll1_div2";
 		div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2)
 		    ? 8 : 10;
 	} else if (!strcmp(name, "sdh")) {
 		parent_name = "pll1";
 		table = cpg_sdh_div_table;
 		shift = 8;
 	} else if (!strcmp(name, "sd0")) {
 		parent_name = "pll1";
 		table = cpg_sd01_div_table;
 		shift = 4;
 	} else if (!strcmp(name, "sd1")) {
 		parent_name = "pll1";
 		table = cpg_sd01_div_table;
 		shift = 0;
 	} else if (!strcmp(name, "z")) {
 		return cpg_z_clk_register(cpg);
 	} else {
 		return ERR_PTR(-EINVAL);
 	}

 	if (!table)
 		return clk_register_fixed_factor(NULL, name, parent_name, 0,
 						 mult, div);
 	else
 		return clk_register_divider_table(NULL, name, parent_name, 0,
 						 cpg->reg + CPG_SDCKCR, shift,
 						 4, 0, table, &cpg->lock);
 }

 static void __init rcar_gen2_cpg_clocks_init(struct device_node *np)
 {
 	const struct cpg_pll_config *config;
 	struct rcar_gen2_cpg *cpg;
 	struct clk **clks;
 	unsigned int i;
 	int num_clks;

 	num_clks = of_property_count_strings(np, "clock-output-names");
 	if (num_clks < 0) {
 		pr_err("%s: failed to count clocks\n", __func__);
 		return;
 	}

 	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
 	clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL);
 	if (cpg == NULL || clks == NULL) {
 		/* We're leaking memory on purpose, there's no point in cleaning
 		 * up as the system won't boot anyway.
 		 */
 		pr_err("%s: failed to allocate cpg\n", __func__);
 		return;
 	}

 	spin_lock_init(&cpg->lock);

 	cpg->data.clks = clks;
 	cpg->data.clk_num = num_clks;

 	cpg->reg = of_iomap(np, 0);
 	if (WARN_ON(cpg->reg == NULL))
 		return;

 	config = &cpg_pll_configs[CPG_PLL_CONFIG_INDEX(cpg_mode)];

 	for (i = 0; i < num_clks; ++i) {
 		const char *name;
 		struct clk *clk;

 		of_property_read_string_index(np, "clock-output-names", i,
 					      &name);

 		clk = rcar_gen2_cpg_register_clock(np, cpg, config, name);
 		if (IS_ERR(clk))
 			pr_err("%s: failed to register %s %s clock (%ld)\n",
 			       __func__, np->name, name, PTR_ERR(clk));
 		else
 			cpg->data.clks[i] = clk;
 	}

 	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
 }
 CLK_OF_DECLARE(rcar_gen2_cpg_clks, "renesas,rcar-gen2-cpg-clocks",
 	       rcar_gen2_cpg_clocks_init);

 void __init rcar_gen2_clocks_init(u32 mode)
 {
 	cpg_mode = mode;

 	of_clk_init(NULL);
 }
	/*
	* rcar_gen2 Core CPG Clocks
	*
	* Copyright (C) 2013 Ideas On Board SPRL
	*
	* Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.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; version 2 of the License.
	*/

	#include <linux/clk-provider.h>
	#include <linux/clkdev.h>
	#include <linux/clk/shmobile.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/math64.h>
	#include <linux/of.h>
	#include <linux/of_address.h>
	#include <linux/spinlock.h>

	struct rcar_gen2_cpg {
	struct clk_onecell_data data;
	spinlock_t lock;
	void __iomem *reg;
	};

	#define CPG_FRQCRB 0x00000004
	#define CPG_FRQCRB_KICK BIT(31)
	#define CPG_SDCKCR 0x00000074
	#define CPG_PLL0CR 0x000000d8
	#define CPG_FRQCRC 0x000000e0
	#define CPG_FRQCRC_ZFC_MASK (0x1f << 8)
	#define CPG_FRQCRC_ZFC_SHIFT 8

	/* -----------------------------------------------------------------------------
	* Z Clock
	*
	* Traits of this clock:
	* prepare - clk_prepare only ensures that parents are prepared
	* enable - clk_enable only ensures that parents are enabled
	* rate - rate is adjustable. clk->rate = parent->rate * mult / 32
	* parent - fixed parent. No clk_set_parent support
	*/

	struct cpg_z_clk {
	struct clk_hw hw;
	void __iomem *reg;
	void __iomem *kick_reg;
	};

	#define to_z_clk(_hw) container_of(_hw, struct cpg_z_clk, hw)

	static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	struct cpg_z_clk *zclk = to_z_clk(hw);
	unsigned int mult;
	unsigned int val;

	val = (clk_readl(zclk->reg) & CPG_FRQCRC_ZFC_MASK)
	>> CPG_FRQCRC_ZFC_SHIFT;
	mult = 32 - val;

	return div_u64((u64)parent_rate * mult, 32);
	}

	static long cpg_z_clk_round_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long *parent_rate)
	{
	unsigned long prate = *parent_rate;
	unsigned int mult;

	if (!prate)
	prate = 1;

	mult = div_u64((u64)rate * 32, prate);
	mult = clamp(mult, 1U, 32U);

	return parent_rate / 32 mult;
	}

	static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	struct cpg_z_clk *zclk = to_z_clk(hw);
	unsigned int mult;
	u32 val, kick;
	unsigned int i;

	mult = div_u64((u64)rate * 32, parent_rate);
	mult = clamp(mult, 1U, 32U);

	if (clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK)
	return -EBUSY;

	val = clk_readl(zclk->reg);
	val &= ~CPG_FRQCRC_ZFC_MASK;
	val \|= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT;
	clk_writel(val, zclk->reg);

	/*
	* Set KICK bit in FRQCRB to update hardware setting and wait for
	* clock change completion.
	*/
	kick = clk_readl(zclk->kick_reg);
	kick \|= CPG_FRQCRB_KICK;
	clk_writel(kick, zclk->kick_reg);

	/*
	* Note: There is no HW information about the worst case latency.
	*
	* Using experimental measurements, it seems that no more than
	* ~10 iterations are needed, independently of the CPU rate.
	* Since this value might be dependant of external xtal rate, pll1
	* rate or even the other emulation clocks rate, use 1000 as a
	* "super" safe value.
	*/
	for (i = 1000; i; i--) {
	if (!(clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK))
	return 0;

	cpu_relax();
	}

	return -ETIMEDOUT;
	}

	static const struct clk_ops cpg_z_clk_ops = {
	.recalc_rate = cpg_z_clk_recalc_rate,
	.round_rate = cpg_z_clk_round_rate,
	.set_rate = cpg_z_clk_set_rate,
	};

	static struct clk * __init cpg_z_clk_register(struct rcar_gen2_cpg *cpg)
	{
	static const char *parent_name = "pll0";
	struct clk_init_data init;
	struct cpg_z_clk *zclk;
	struct clk *clk;

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

	init.name = "z";
	init.ops = &cpg_z_clk_ops;
	init.flags = 0;
	init.parent_names = &parent_name;
	init.num_parents = 1;

	zclk->reg = cpg->reg + CPG_FRQCRC;
	zclk->kick_reg = cpg->reg + CPG_FRQCRB;
	zclk->hw.init = &init;

	clk = clk_register(NULL, &zclk->hw);
	if (IS_ERR(clk))
	kfree(zclk);

	return clk;
	}

	/* -----------------------------------------------------------------------------
	* CPG Clock Data
	*/

	/*
	* MD EXTAL PLL0 PLL1 PLL3
	* 14 13 19 (MHz) 1 1
	*---------------------------------------------------
	* 0 0 0 15 x 1 x172/2 x208/2 x106
	* 0 0 1 15 x 1 x172/2 x208/2 x88
	* 0 1 0 20 x 1 x130/2 x156/2 x80
	* 0 1 1 20 x 1 x130/2 x156/2 x66
	* 1 0 0 26 / 2 x200/2 x240/2 x122
	* 1 0 1 26 / 2 x200/2 x240/2 x102
	* 1 1 0 30 / 2 x172/2 x208/2 x106
	* 1 1 1 30 / 2 x172/2 x208/2 x88
	*
	* *1 : Table 7.6 indicates VCO ouput (PLLx = VCO/2)
	*/
	#define CPG_PLL_CONFIG_INDEX(md) ((((md) & BIT(14)) >> 12) \| \
	(((md) & BIT(13)) >> 12) \| \
	(((md) & BIT(19)) >> 19))
	struct cpg_pll_config {
	unsigned int extal_div;
	unsigned int pll1_mult;
	unsigned int pll3_mult;
	};

	static const struct cpg_pll_config cpg_pll_configs[8] __initconst = {
	{ 1, 208, 106 }, { 1, 208, 88 }, { 1, 156, 80 }, { 1, 156, 66 },
	{ 2, 240, 122 }, { 2, 240, 102 }, { 2, 208, 106 }, { 2, 208, 88 },
	};

	/* SDHI divisors */
	static const struct clk_div_table cpg_sdh_div_table[] = {
	{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 },
	{ 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 },
	{ 8, 24 }, { 10, 36 }, { 11, 48 }, { 0, 0 },
	};

	static const struct clk_div_table cpg_sd01_div_table[] = {
	{ 4, 8 },
	{ 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 },
	{ 10, 36 }, { 11, 48 }, { 12, 10 }, { 0, 0 },
	};

	/* -----------------------------------------------------------------------------
	* Initialization
	*/

	static u32 cpg_mode __initdata;

	static struct clk * __init
	rcar_gen2_cpg_register_clock(struct device_node np, struct rcar_gen2_cpg cpg,
	const struct cpg_pll_config *config,
	const char *name)
	{
	const struct clk_div_table *table = NULL;
	const char *parent_name;
	unsigned int shift;
	unsigned int mult = 1;
	unsigned int div = 1;

	if (!strcmp(name, "main")) {
	parent_name = of_clk_get_parent_name(np, 0);
	div = config->extal_div;
	} else if (!strcmp(name, "pll0")) {
	/* PLL0 is a configurable multiplier clock. Register it as a
	* fixed factor clock for now as there's no generic multiplier
	* clock implementation and we currently have no need to change
	* the multiplier value.
	*/
	u32 value = clk_readl(cpg->reg + CPG_PLL0CR);
	parent_name = "main";
	mult = ((value >> 24) & ((1 << 7) - 1)) + 1;
	} else if (!strcmp(name, "pll1")) {
	parent_name = "main";
	mult = config->pll1_mult / 2;
	} else if (!strcmp(name, "pll3")) {
	parent_name = "main";
	mult = config->pll3_mult;
	} else if (!strcmp(name, "lb")) {
	parent_name = "pll1";
	div = cpg_mode & BIT(18) ? 36 : 24;
	} else if (!strcmp(name, "qspi")) {
	parent_name = "pll1_div2";
	div = (cpg_mode & (BIT(3) \| BIT(2) \| BIT(1))) == BIT(2)
	? 8 : 10;
	} else if (!strcmp(name, "sdh")) {
	parent_name = "pll1";
	table = cpg_sdh_div_table;
	shift = 8;
	} else if (!strcmp(name, "sd0")) {
	parent_name = "pll1";
	table = cpg_sd01_div_table;
	shift = 4;
	} else if (!strcmp(name, "sd1")) {
	parent_name = "pll1";
	table = cpg_sd01_div_table;
	shift = 0;
	} else if (!strcmp(name, "z")) {
	return cpg_z_clk_register(cpg);
	} else {
	return ERR_PTR(-EINVAL);
	}

	if (!table)
	return clk_register_fixed_factor(NULL, name, parent_name, 0,
	mult, div);
	else
	return clk_register_divider_table(NULL, name, parent_name, 0,
	cpg->reg + CPG_SDCKCR, shift,
	4, 0, table, &cpg->lock);
	}

	static void __init rcar_gen2_cpg_clocks_init(struct device_node *np)
	{
	const struct cpg_pll_config *config;
	struct rcar_gen2_cpg *cpg;
	struct clk **clks;
	unsigned int i;
	int num_clks;

	num_clks = of_property_count_strings(np, "clock-output-names");
	if (num_clks < 0) {
	pr_err("%s: failed to count clocks\n", __func__);
	return;
	}

	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
	clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL);
	if (cpg == NULL \|\| clks == NULL) {
	/* We're leaking memory on purpose, there's no point in cleaning
	* up as the system won't boot anyway.
	*/
	pr_err("%s: failed to allocate cpg\n", __func__);
	return;
	}

	spin_lock_init(&cpg->lock);

	cpg->data.clks = clks;
	cpg->data.clk_num = num_clks;

	cpg->reg = of_iomap(np, 0);
	if (WARN_ON(cpg->reg == NULL))
	return;

	config = &cpg_pll_configs[CPG_PLL_CONFIG_INDEX(cpg_mode)];

	for (i = 0; i < num_clks; ++i) {
	const char *name;
	struct clk *clk;

	of_property_read_string_index(np, "clock-output-names", i,
	&name);

	clk = rcar_gen2_cpg_register_clock(np, cpg, config, name);
	if (IS_ERR(clk))
	pr_err("%s: failed to register %s %s clock (%ld)\n",
	__func__, np->name, name, PTR_ERR(clk));
	else
	cpg->data.clks[i] = clk;
	}

	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
	}
	CLK_OF_DECLARE(rcar_gen2_cpg_clks, "renesas,rcar-gen2-cpg-clocks",
	rcar_gen2_cpg_clocks_init);

	void __init rcar_gen2_clocks_init(u32 mode)
	{
	cpg_mode = mode;

	of_clk_init(NULL);
	}