drivers/clk/samsung/clk-pll.c

/*
 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
 * Copyright (c) 2013 Linaro Ltd.
 *
 * 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.
 *
 * This file contains the utility functions to register the pll clocks.
*/

#include <linux/errno.h>
#include "clk.h"
#include "clk-pll.h"

struct samsung_clk_pll {
	struct clk_hw		hw;
	void __iomem		*lock_reg;
	void __iomem		*con_reg;
	enum samsung_pll_type	type;
	unsigned int		rate_count;
	const struct samsung_pll_rate_table *rate_table;
};

#define to_clk_pll(_hw) container_of(_hw, struct samsung_clk_pll, hw)

static const struct samsung_pll_rate_table *samsung_get_pll_settings(
				struct samsung_clk_pll *pll, unsigned long rate)
{
	const struct samsung_pll_rate_table  *rate_table = pll->rate_table;
	int i;

	for (i = 0; i < pll->rate_count; i++) {
		if (rate == rate_table[i].rate)
			return &rate_table[i];
	}

	return NULL;
}

static long samsung_pll_round_rate(struct clk_hw *hw,
			unsigned long drate, unsigned long *prate)
{
	struct samsung_clk_pll *pll = to_clk_pll(hw);
	const struct samsung_pll_rate_table *rate_table = pll->rate_table;
	int i;

	/* Assumming rate_table is in descending order */
	for (i = 0; i < pll->rate_count; i++) {
		if (drate >= rate_table[i].rate)
			return rate_table[i].rate;
	}

	/* return minimum supported value */
	return rate_table[i - 1].rate;
}

/*
 * PLL35xx Clock Type
 */
/* Maximum lock time can be 270 * PDIV cycles */
#define PLL35XX_LOCK_FACTOR	(270)

#define PLL35XX_MDIV_MASK       (0x3FF)
#define PLL35XX_PDIV_MASK       (0x3F)
#define PLL35XX_SDIV_MASK       (0x7)
#define PLL35XX_LOCK_STAT_MASK	(0x1)
#define PLL35XX_MDIV_SHIFT      (16)
#define PLL35XX_PDIV_SHIFT      (8)
#define PLL35XX_SDIV_SHIFT      (0)
#define PLL35XX_LOCK_STAT_SHIFT	(29)

static unsigned long samsung_pll35xx_recalc_rate(struct clk_hw *hw,
				unsigned long parent_rate)
{
	struct samsung_clk_pll *pll = to_clk_pll(hw);
	u32 mdiv, pdiv, sdiv, pll_con;
	u64 fvco = parent_rate;

	pll_con = __raw_readl(pll->con_reg);
	mdiv = (pll_con >> PLL35XX_MDIV_SHIFT) & PLL35XX_MDIV_MASK;
	pdiv = (pll_con >> PLL35XX_PDIV_SHIFT) & PLL35XX_PDIV_MASK;
	sdiv = (pll_con >> PLL35XX_SDIV_SHIFT) & PLL35XX_SDIV_MASK;

	fvco *= mdiv;
	do_div(fvco, (pdiv << sdiv));

	return (unsigned long)fvco;
}

static inline bool samsung_pll35xx_mp_change(
		const struct samsung_pll_rate_table *rate, u32 pll_con)
{
	u32 old_mdiv, old_pdiv;

	old_mdiv = (pll_con >> PLL35XX_MDIV_SHIFT) & PLL35XX_MDIV_MASK;
	old_pdiv = (pll_con >> PLL35XX_PDIV_SHIFT) & PLL35XX_PDIV_MASK;

	return (rate->mdiv != old_mdiv || rate->pdiv != old_pdiv);
}

static int samsung_pll35xx_set_rate(struct clk_hw *hw, unsigned long drate,
					unsigned long prate)
{
	struct samsung_clk_pll *pll = to_clk_pll(hw);
	const struct samsung_pll_rate_table *rate;
	u32 tmp;

	/* Get required rate settings from table */
	rate = samsung_get_pll_settings(pll, drate);
	if (!rate) {
		pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
			drate, __clk_get_name(hw->clk));
		return -EINVAL;
	}

	tmp = __raw_readl(pll->con_reg);

	if (!(samsung_pll35xx_mp_change(rate, tmp))) {
		/* If only s change, change just s value only*/
		tmp &= ~(PLL35XX_SDIV_MASK << PLL35XX_SDIV_SHIFT);
		tmp |= rate->sdiv << PLL35XX_SDIV_SHIFT;
		__raw_writel(tmp, pll->con_reg);

		return 0;
	}

	/* Set PLL lock time. */
	__raw_writel(rate->pdiv * PLL35XX_LOCK_FACTOR,
			pll->lock_reg);

	/* Change PLL PMS values */
	tmp &= ~((PLL35XX_MDIV_MASK << PLL35XX_MDIV_SHIFT) |
			(PLL35XX_PDIV_MASK << PLL35XX_PDIV_SHIFT) |
			(PLL35XX_SDIV_MASK << PLL35XX_SDIV_SHIFT));
	tmp |= (rate->mdiv << PLL35XX_MDIV_SHIFT) |
			(rate->pdiv << PLL35XX_PDIV_SHIFT) |
			(rate->sdiv << PLL35XX_SDIV_SHIFT);
	__raw_writel(tmp, pll->con_reg);

	/* wait_lock_time */
	do {
		cpu_relax();
		tmp = __raw_readl(pll->con_reg);
	} while (!(tmp & (PLL35XX_LOCK_STAT_MASK
				<< PLL35XX_LOCK_STAT_SHIFT)));
	return 0;
}

static const struct clk_ops samsung_pll35xx_clk_ops = {
	.recalc_rate = samsung_pll35xx_recalc_rate,
	.round_rate = samsung_pll_round_rate,
	.set_rate = samsung_pll35xx_set_rate,
};

static const struct clk_ops samsung_pll35xx_clk_min_ops = {
	.recalc_rate = samsung_pll35xx_recalc_rate,
};

/*
 * PLL36xx Clock Type
 */

#define PLL36XX_KDIV_MASK	(0xFFFF)
#define PLL36XX_MDIV_MASK	(0x1FF)
#define PLL36XX_PDIV_MASK	(0x3F)
#define PLL36XX_SDIV_MASK	(0x7)
#define PLL36XX_MDIV_SHIFT	(16)
#define PLL36XX_PDIV_SHIFT	(8)
#define PLL36XX_SDIV_SHIFT	(0)

static unsigned long samsung_pll36xx_recalc_rate(struct clk_hw *hw,
				unsigned long parent_rate)
{
	struct samsung_clk_pll *pll = to_clk_pll(hw);
	u32 mdiv, pdiv, sdiv, pll_con0, pll_con1;
	s16 kdiv;
	u64 fvco = parent_rate;

	pll_con0 = __raw_readl(pll->con_reg);
	pll_con1 = __raw_readl(pll->con_reg + 4);
	mdiv = (pll_con0 >> PLL36XX_MDIV_SHIFT) & PLL36XX_MDIV_MASK;
	pdiv = (pll_con0 >> PLL36XX_PDIV_SHIFT) & PLL36XX_PDIV_MASK;
	sdiv = (pll_con0 >> PLL36XX_SDIV_SHIFT) & PLL36XX_SDIV_MASK;
	kdiv = (s16)(pll_con1 & PLL36XX_KDIV_MASK);

	fvco *= (mdiv << 16) + kdiv;
	do_div(fvco, (pdiv << sdiv));
	fvco >>= 16;

	return (unsigned long)fvco;
}

static const struct clk_ops samsung_pll36xx_clk_ops = {
	.recalc_rate = samsung_pll36xx_recalc_rate,
};

/*
 * PLL45xx Clock Type
 */

#define PLL45XX_MDIV_MASK	(0x3FF)
#define PLL45XX_PDIV_MASK	(0x3F)
#define PLL45XX_SDIV_MASK	(0x7)
#define PLL45XX_MDIV_SHIFT	(16)
#define PLL45XX_PDIV_SHIFT	(8)
#define PLL45XX_SDIV_SHIFT	(0)

struct samsung_clk_pll45xx {
	struct clk_hw		hw;
	enum pll45xx_type	type;
	const void __iomem	*con_reg;
};

#define to_clk_pll45xx(_hw) container_of(_hw, struct samsung_clk_pll45xx, hw)

static unsigned long samsung_pll45xx_recalc_rate(struct clk_hw *hw,
				unsigned long parent_rate)
{
	struct samsung_clk_pll45xx *pll = to_clk_pll45xx(hw);
	u32 mdiv, pdiv, sdiv, pll_con;
	u64 fvco = parent_rate;

	pll_con = __raw_readl(pll->con_reg);
	mdiv = (pll_con >> PLL45XX_MDIV_SHIFT) & PLL45XX_MDIV_MASK;
	pdiv = (pll_con >> PLL45XX_PDIV_SHIFT) & PLL45XX_PDIV_MASK;
	sdiv = (pll_con >> PLL45XX_SDIV_SHIFT) & PLL45XX_SDIV_MASK;

	if (pll->type == pll_4508)
		sdiv = sdiv - 1;

	fvco *= mdiv;
	do_div(fvco, (pdiv << sdiv));

	return (unsigned long)fvco;
}

static const struct clk_ops samsung_pll45xx_clk_ops = {
	.recalc_rate = samsung_pll45xx_recalc_rate,
};

struct clk * __init samsung_clk_register_pll45xx(const char *name,
			const char *pname, const void __iomem *con_reg,
			enum pll45xx_type type)
{
	struct samsung_clk_pll45xx *pll;
	struct clk *clk;
	struct clk_init_data init;

	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
	if (!pll) {
		pr_err("%s: could not allocate pll clk %s\n", __func__, name);
		return NULL;
	}

	init.name = name;
	init.ops = &samsung_pll45xx_clk_ops;
	init.flags = CLK_GET_RATE_NOCACHE;
	init.parent_names = &pname;
	init.num_parents = 1;

	pll->hw.init = &init;
	pll->con_reg = con_reg;
	pll->type = type;

	clk = clk_register(NULL, &pll->hw);
	if (IS_ERR(clk)) {
		pr_err("%s: failed to register pll clock %s\n", __func__,
				name);
		kfree(pll);
	}

	if (clk_register_clkdev(clk, name, NULL))
		pr_err("%s: failed to register lookup for %s", __func__, name);

	return clk;
}

/*
 * PLL46xx Clock Type
 */

#define PLL46XX_MDIV_MASK	(0x1FF)
#define PLL46XX_PDIV_MASK	(0x3F)
#define PLL46XX_SDIV_MASK	(0x7)
#define PLL46XX_MDIV_SHIFT	(16)
#define PLL46XX_PDIV_SHIFT	(8)
#define PLL46XX_SDIV_SHIFT	(0)

#define PLL46XX_KDIV_MASK	(0xFFFF)
#define PLL4650C_KDIV_MASK	(0xFFF)
#define PLL46XX_KDIV_SHIFT	(0)

struct samsung_clk_pll46xx {
	struct clk_hw		hw;
	enum pll46xx_type	type;
	const void __iomem	*con_reg;
};

#define to_clk_pll46xx(_hw) container_of(_hw, struct samsung_clk_pll46xx, hw)

static unsigned long samsung_pll46xx_recalc_rate(struct clk_hw *hw,
				unsigned long parent_rate)
{
	struct samsung_clk_pll46xx *pll = to_clk_pll46xx(hw);
	u32 mdiv, pdiv, sdiv, kdiv, pll_con0, pll_con1, shift;
	u64 fvco = parent_rate;

	pll_con0 = __raw_readl(pll->con_reg);
	pll_con1 = __raw_readl(pll->con_reg + 4);
	mdiv = (pll_con0 >> PLL46XX_MDIV_SHIFT) & PLL46XX_MDIV_MASK;
	pdiv = (pll_con0 >> PLL46XX_PDIV_SHIFT) & PLL46XX_PDIV_MASK;
	sdiv = (pll_con0 >> PLL46XX_SDIV_SHIFT) & PLL46XX_SDIV_MASK;
	kdiv = pll->type == pll_4650c ? pll_con1 & PLL4650C_KDIV_MASK :
					pll_con1 & PLL46XX_KDIV_MASK;

	shift = pll->type == pll_4600 ? 16 : 10;
	fvco *= (mdiv << shift) + kdiv;
	do_div(fvco, (pdiv << sdiv));
	fvco >>= shift;

	return (unsigned long)fvco;
}

static const struct clk_ops samsung_pll46xx_clk_ops = {
	.recalc_rate = samsung_pll46xx_recalc_rate,
};

struct clk * __init samsung_clk_register_pll46xx(const char *name,
			const char *pname, const void __iomem *con_reg,
			enum pll46xx_type type)
{
	struct samsung_clk_pll46xx *pll;
	struct clk *clk;
	struct clk_init_data init;

	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
	if (!pll) {
		pr_err("%s: could not allocate pll clk %s\n", __func__, name);
		return NULL;
	}

	init.name = name;
	init.ops = &samsung_pll46xx_clk_ops;
	init.flags = CLK_GET_RATE_NOCACHE;
	init.parent_names = &pname;
	init.num_parents = 1;

	pll->hw.init = &init;
	pll->con_reg = con_reg;
	pll->type = type;

	clk = clk_register(NULL, &pll->hw);
	if (IS_ERR(clk)) {
		pr_err("%s: failed to register pll clock %s\n", __func__,
				name);
		kfree(pll);
	}

	if (clk_register_clkdev(clk, name, NULL))
		pr_err("%s: failed to register lookup for %s", __func__, name);

	return clk;
}

/*
 * PLL2550x Clock Type
 */

#define PLL2550X_R_MASK       (0x1)
#define PLL2550X_P_MASK       (0x3F)
#define PLL2550X_M_MASK       (0x3FF)
#define PLL2550X_S_MASK       (0x7)
#define PLL2550X_R_SHIFT      (20)
#define PLL2550X_P_SHIFT      (14)
#define PLL2550X_M_SHIFT      (4)
#define PLL2550X_S_SHIFT      (0)

struct samsung_clk_pll2550x {
	struct clk_hw		hw;
	const void __iomem	*reg_base;
	unsigned long		offset;
};

#define to_clk_pll2550x(_hw) container_of(_hw, struct samsung_clk_pll2550x, hw)

static unsigned long samsung_pll2550x_recalc_rate(struct clk_hw *hw,
				unsigned long parent_rate)
{
	struct samsung_clk_pll2550x *pll = to_clk_pll2550x(hw);
	u32 r, p, m, s, pll_stat;
	u64 fvco = parent_rate;

	pll_stat = __raw_readl(pll->reg_base + pll->offset * 3);
	r = (pll_stat >> PLL2550X_R_SHIFT) & PLL2550X_R_MASK;
	if (!r)
		return 0;
	p = (pll_stat >> PLL2550X_P_SHIFT) & PLL2550X_P_MASK;
	m = (pll_stat >> PLL2550X_M_SHIFT) & PLL2550X_M_MASK;
	s = (pll_stat >> PLL2550X_S_SHIFT) & PLL2550X_S_MASK;

	fvco *= m;
	do_div(fvco, (p << s));

	return (unsigned long)fvco;
}

static const struct clk_ops samsung_pll2550x_clk_ops = {
	.recalc_rate = samsung_pll2550x_recalc_rate,
};

struct clk * __init samsung_clk_register_pll2550x(const char *name,
			const char *pname, const void __iomem *reg_base,
			const unsigned long offset)
{
	struct samsung_clk_pll2550x *pll;
	struct clk *clk;
	struct clk_init_data init;

	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
	if (!pll) {
		pr_err("%s: could not allocate pll clk %s\n", __func__, name);
		return NULL;
	}

	init.name = name;
	init.ops = &samsung_pll2550x_clk_ops;
	init.flags = CLK_GET_RATE_NOCACHE;
	init.parent_names = &pname;
	init.num_parents = 1;

	pll->hw.init = &init;
	pll->reg_base = reg_base;
	pll->offset = offset;

	clk = clk_register(NULL, &pll->hw);
	if (IS_ERR(clk)) {
		pr_err("%s: failed to register pll clock %s\n", __func__,
				name);
		kfree(pll);
	}

	if (clk_register_clkdev(clk, name, NULL))
		pr_err("%s: failed to register lookup for %s", __func__, name);

	return clk;
}

static void __init _samsung_clk_register_pll(struct samsung_pll_clock *pll_clk,
						void __iomem *base)
{
	struct samsung_clk_pll *pll;
	struct clk *clk;
	struct clk_init_data init;
	int ret, len;

	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
	if (!pll) {
		pr_err("%s: could not allocate pll clk %s\n",
			__func__, pll_clk->name);
		return;
	}

	init.name = pll_clk->name;
	init.flags = pll_clk->flags;
	init.parent_names = &pll_clk->parent_name;
	init.num_parents = 1;

	if (pll_clk->rate_table) {
		/* find count of rates in rate_table */
		for (len = 0; pll_clk->rate_table[len].rate != 0; )
			len++;

		pll->rate_count = len;
		pll->rate_table = kmemdup(pll_clk->rate_table,
					pll->rate_count *
					sizeof(struct samsung_pll_rate_table),
					GFP_KERNEL);
		WARN(!pll->rate_table,
			"%s: could not allocate rate table for %s\n",
			__func__, pll_clk->name);
	}

	switch (pll_clk->type) {
	/* clk_ops for 35xx and 2550 are similar */
	case pll_35xx:
	case pll_2550:
		if (!pll->rate_table)
			init.ops = &samsung_pll35xx_clk_min_ops;
		else
			init.ops = &samsung_pll35xx_clk_ops;
		break;
	/* clk_ops for 36xx and 2650 are similar */
	case pll_36xx:
	case pll_2650:
		init.ops = &samsung_pll36xx_clk_ops;
		break;
	default:
		pr_warn("%s: Unknown pll type for pll clk %s\n",
			__func__, pll_clk->name);
	}

	pll->hw.init = &init;
	pll->type = pll_clk->type;
	pll->lock_reg = base + pll_clk->lock_offset;
	pll->con_reg = base + pll_clk->con_offset;

	clk = clk_register(NULL, &pll->hw);
	if (IS_ERR(clk)) {
		pr_err("%s: failed to register pll clock %s : %ld\n",
			__func__, pll_clk->name, PTR_ERR(clk));
		kfree(pll);
		return;
	}

	samsung_clk_add_lookup(clk, pll_clk->id);

	if (!pll_clk->alias)
		return;

	ret = clk_register_clkdev(clk, pll_clk->alias, pll_clk->dev_name);
	if (ret)
		pr_err("%s: failed to register lookup for %s : %d",
			__func__, pll_clk->name, ret);
}

void __init samsung_clk_register_pll(struct samsung_pll_clock *pll_list,
				unsigned int nr_pll, void __iomem *base)
{
	int cnt;

	for (cnt = 0; cnt < nr_pll; cnt++)
		_samsung_clk_register_pll(&pll_list[cnt], base);
}