clk: renesas: cpg-mssr: Add common R-Car Gen2 support

/*

 * R-Car Gen2 Clock Pulse Generator

 *

 * Copyright (C) 2016 Cogent Embedded Inc.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 as published

 * by the Free Software Foundation.

 */

#include <linux/bug.h>

#include <linux/clk.h>

#include <linux/clk-provider.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/init.h>

#include <linux/io.h>

#include <linux/slab.h>

#include "renesas-cpg-mssr.h"

#include "rcar-gen2-cpg.h"

#define CPG_FRQCRB		0x0004

#define CPG_FRQCRB_KICK		BIT(31)

#define CPG_SDCKCR		0x0074

#define CPG_PLL0CR		0x00d8

#define CPG_PLL0CR_STC_SHIFT	24

#define CPG_PLL0CR_STC_MASK	(0x7f << CPG_PLL0CR_STC_SHIFT)

#define CPG_FRQCRC		0x00e0

#define CPG_FRQCRC_ZFC_SHIFT	8

#define CPG_FRQCRC_ZFC_MASK	(0x1f << CPG_FRQCRC_ZFC_SHIFT)

#define CPG_ADSPCKCR		0x025c

#define CPG_RCANCKCR		0x0270

static spinlock_t cpg_lock;

/*

 * 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 = (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 (readl(zclk->kick_reg) & CPG_FRQCRB_KICK)

		return -EBUSY;

	val = readl(zclk->reg);

	val &= ~CPG_FRQCRC_ZFC_MASK;

	val |= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT;

	writel(val, zclk->reg);

	/*

	 * Set KICK bit in FRQCRB to update hardware setting and wait for

	 * clock change completion.

	 */

	kick = readl(zclk->kick_reg);

	kick |= CPG_FRQCRB_KICK;

	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 dependent on 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 (!(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(const char *name,

					      const char *parent_name,

					      void __iomem *base)

{

	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 = name;

	init.ops = &cpg_z_clk_ops;

	init.flags = 0;

	init.parent_names = &parent_name;

	init.num_parents = 1;

	zclk->reg = base + CPG_FRQCRC;

	zclk->kick_reg = base + CPG_FRQCRB;

	zclk->hw.init = &init;

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

	if (IS_ERR(clk))

		kfree(zclk);

	return clk;

}

static struct clk * __init cpg_rcan_clk_register(const char *name,

						 const char *parent_name,

						 void __iomem *base)

{

	struct clk_fixed_factor *fixed;

	struct clk_gate *gate;

	struct clk *clk;

	fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);

	if (!fixed)

		return ERR_PTR(-ENOMEM);

	fixed->mult = 1;

	fixed->div = 6;

	gate = kzalloc(sizeof(*gate), GFP_KERNEL);

	if (!gate) {

		kfree(fixed);

		return ERR_PTR(-ENOMEM);

	}

	gate->reg = base + CPG_RCANCKCR;

	gate->bit_idx = 8;

	gate->flags = CLK_GATE_SET_TO_DISABLE;

	gate->lock = &cpg_lock;

	clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,

				     &fixed->hw, &clk_fixed_factor_ops,

				     &gate->hw, &clk_gate_ops, 0);

	if (IS_ERR(clk)) {

		kfree(gate);

		kfree(fixed);

	}

	return clk;

}

/* ADSP divisors */

static const struct clk_div_table cpg_adsp_div_table[] = {

	{  1,  3 }, {  2,  4 }, {  3,  6 }, {  4,  8 },

	{  5, 12 }, {  6, 16 }, {  7, 18 }, {  8, 24 },

	{ 10, 36 }, { 11, 48 }, {  0,  0 },

};

static struct clk * __init cpg_adsp_clk_register(const char *name,

						 const char *parent_name,

						 void __iomem *base)

{

	struct clk_divider *div;

	struct clk_gate *gate;

	struct clk *clk;

	div = kzalloc(sizeof(*div), GFP_KERNEL);

	if (!div)

		return ERR_PTR(-ENOMEM);

	div->reg = base + CPG_ADSPCKCR;

	div->width = 4;

	div->table = cpg_adsp_div_table;

	div->lock = &cpg_lock;

	gate = kzalloc(sizeof(*gate), GFP_KERNEL);

	if (!gate) {

		kfree(div);

		return ERR_PTR(-ENOMEM);

	}

	gate->reg = base + CPG_ADSPCKCR;

	gate->bit_idx = 8;

	gate->flags = CLK_GATE_SET_TO_DISABLE;

	gate->lock = &cpg_lock;

	clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,

				     &div->hw, &clk_divider_ops,

				     &gate->hw, &clk_gate_ops, 0);

	if (IS_ERR(clk)) {

		kfree(gate);

		kfree(div);

	}

	return clk;

}

/* 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 },

};

static const struct rcar_gen2_cpg_pll_config *cpg_pll_config __initdata;

static unsigned int cpg_pll0_div __initdata;

static u32 cpg_mode __initdata;

struct clk * __init rcar_gen2_cpg_clk_register(struct device *dev,

					       const struct cpg_core_clk *core,

					       const struct cpg_mssr_info *info,

					       struct clk **clks,

					       void __iomem *base)

{

	const struct clk_div_table *table = NULL;

	const struct clk *parent;

	const char *parent_name;

	unsigned int mult = 1;

	unsigned int div = 1;

	unsigned int shift;

	parent = clks[core->parent];

	if (IS_ERR(parent))

		return ERR_CAST(parent);

	parent_name = __clk_get_name(parent);

	switch (core->type) {

	/* R-Car Gen2 */

	case CLK_TYPE_GEN2_MAIN:

		div = cpg_pll_config->extal_div;

		break;

	case CLK_TYPE_GEN2_PLL0:

		/*

		 * PLL0 is a  configurable multiplier clock except on R-Car

		 * V2H/E2. Register the PLL0 clock 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.

		 */

		mult = cpg_pll_config->pll0_mult;

		div  = cpg_pll0_div;

		if (!mult) {

			u32 pll0cr = readl(base + CPG_PLL0CR);

			mult = (((pll0cr & CPG_PLL0CR_STC_MASK) >>

				 CPG_PLL0CR_STC_SHIFT) + 1) * 2;

		}

		break;

	case CLK_TYPE_GEN2_PLL1:

		mult = cpg_pll_config->pll1_mult / 2;

		break;

	case CLK_TYPE_GEN2_PLL3:

		mult = cpg_pll_config->pll3_mult;

		break;

	case CLK_TYPE_GEN2_Z:

		return cpg_z_clk_register(core->name, parent_name, base);

	case CLK_TYPE_GEN2_LB:

		div = cpg_mode & BIT(18) ? 36 : 24;

		break;

	case CLK_TYPE_GEN2_ADSP:

		return cpg_adsp_clk_register(core->name, parent_name, base);

	case CLK_TYPE_GEN2_SDH:

		table = cpg_sdh_div_table;

		shift = 8;

		break;

	case CLK_TYPE_GEN2_SD0:

		table = cpg_sd01_div_table;

		shift = 4;

		break;

	case CLK_TYPE_GEN2_SD1:

		table = cpg_sd01_div_table;

		shift = 0;

		break;

	case CLK_TYPE_GEN2_QSPI:

		div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2) ?

		      8 : 10;

		break;

	case CLK_TYPE_GEN2_RCAN:

		return cpg_rcan_clk_register(core->name, parent_name, base);

	default:

		return ERR_PTR(-EINVAL);

	}

	if (!table)

		return clk_register_fixed_factor(NULL, core->name, parent_name,

						 0, mult, div);

	else

		return clk_register_divider_table(NULL, core->name,

						  parent_name, 0,

						  base + CPG_SDCKCR, shift, 4,

						  0, table, &cpg_lock);

}

int __init rcar_gen2_cpg_init(const struct rcar_gen2_cpg_pll_config *config,

			      unsigned int pll0_div, u32 mode)

{

	cpg_pll_config = config;

	cpg_pll0_div = pll0_div;

	cpg_mode = mode;

	spin_lock_init(&cpg_lock);

	return 0;

}

/*

 * R-Car Gen2 Clock Pulse Generator

 *

 * Copyright (C) 2016 Cogent Embedded Inc.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 as published

 * by the Free Software Foundation; version 2 of the License.

 */

#ifndef __CLK_RENESAS_RCAR_GEN2_CPG_H__

#define __CLK_RENESAS_RCAR_GEN2_CPG_H__

enum rcar_gen2_clk_types {

	CLK_TYPE_GEN2_MAIN = CLK_TYPE_CUSTOM,

	CLK_TYPE_GEN2_PLL0,

	CLK_TYPE_GEN2_PLL1,

	CLK_TYPE_GEN2_PLL3,

	CLK_TYPE_GEN2_Z,

	CLK_TYPE_GEN2_LB,

	CLK_TYPE_GEN2_ADSP,

	CLK_TYPE_GEN2_SDH,

	CLK_TYPE_GEN2_SD0,

	CLK_TYPE_GEN2_SD1,

	CLK_TYPE_GEN2_QSPI,

	CLK_TYPE_GEN2_RCAN,

};

struct rcar_gen2_cpg_pll_config {

	unsigned int extal_div;

	unsigned int pll1_mult;

	unsigned int pll3_mult;

	unsigned int pll0_mult;		/* leave as zero if PLL0CR exists */

};

struct clk *rcar_gen2_cpg_clk_register(struct device *dev,

				       const struct cpg_core_clk *core,

				       const struct cpg_mssr_info *info,

				       struct clk **clks, void __iomem *base);

int rcar_gen2_cpg_init(const struct rcar_gen2_cpg_pll_config *config,

		       unsigned int pll0_div, u32 mode);

#endif