Commit 3e37b005 authored by Chunyan Zhang's avatar Chunyan Zhang Committed by Stephen Boyd
Browse files

clk: sprd: add adjustable pll support 



Introduced a common adjustable pll clock driver for Spreadtrum SoCs.

Signed-off-by: default avatarChunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 4fcba55c

drivers/clk/sprd/Makefile

+1 −0
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@@ -5,3 +5,4 @@ clk-sprd-y += gate.o 
clk-sprd-y	+= mux.o

clk-sprd-y	+= div.o

clk-sprd-y	+= composite.o

clk-sprd-y	+= pll.o

drivers/clk/sprd/pll.c

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// SPDX-License-Identifier: GPL-2.0

//

// Spreadtrum pll clock driver

//

// Copyright (C) 2015~2017 Spreadtrum, Inc.

// Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>



#include <linux/delay.h>

#include <linux/err.h>

#include <linux/regmap.h>

#include <linux/slab.h>



#include "pll.h"



#define CLK_PLL_1M	1000000

#define CLK_PLL_10M	(CLK_PLL_1M * 10)



#define pindex(pll, member)		\

	(pll->factors[member].shift / (8 * sizeof(pll->regs_num)))



#define pshift(pll, member)		\

	(pll->factors[member].shift % (8 * sizeof(pll->regs_num)))



#define pwidth(pll, member)		\

	pll->factors[member].width



#define pmask(pll, member)					\

	((pwidth(pll, member)) ?				\

	GENMASK(pwidth(pll, member) + pshift(pll, member) - 1,	\

	pshift(pll, member)) : 0)



#define pinternal(pll, cfg, member)	\

	(cfg[pindex(pll, member)] & pmask(pll, member))



#define pinternal_val(pll, cfg, member)	\

	(pinternal(pll, cfg, member) >> pshift(pll, member))



static inline unsigned int

sprd_pll_read(const struct sprd_pll *pll, u8 index)

{

	const struct sprd_clk_common *common = &pll->common;

	unsigned int val = 0;



	if (WARN_ON(index >= pll->regs_num))

		return 0;



	regmap_read(common->regmap, common->reg + index * 4, &val);



	return val;

}



static inline void

sprd_pll_write(const struct sprd_pll *pll, u8 index,

				  u32 msk, u32 val)

{

	const struct sprd_clk_common *common = &pll->common;

	unsigned int offset, reg;

	int ret = 0;



	if (WARN_ON(index >= pll->regs_num))

		return;



	offset = common->reg + index * 4;

	ret = regmap_read(common->regmap, offset, &reg);

	if (!ret)

		regmap_write(common->regmap, offset, (reg & ~msk) | val);

}



static unsigned long pll_get_refin(const struct sprd_pll *pll)

{

	u32 shift, mask, index, refin_id = 3;

	const unsigned long refin[4] = { 2, 4, 13, 26 };



	if (pwidth(pll, PLL_REFIN)) {

		index = pindex(pll, PLL_REFIN);

		shift = pshift(pll, PLL_REFIN);

		mask = pmask(pll, PLL_REFIN);

		refin_id = (sprd_pll_read(pll, index) & mask) >> shift;

		if (refin_id > 3)

			refin_id = 3;

	}



	return refin[refin_id];

}



static u32 pll_get_ibias(u64 rate, const u64 *table)

{

	u32 i, num = table[0];



	for (i = 1; i < num + 1; i++)

		if (rate <= table[i])

			break;



	return (i == num + 1) ? num : i;

}



static unsigned long _sprd_pll_recalc_rate(const struct sprd_pll *pll,

					   unsigned long parent_rate)

{

	u32 *cfg;

	u32 i, mask, regs_num = pll->regs_num;

	unsigned long rate, nint, kint = 0;

	u64 refin;

	u16 k1, k2;



	cfg = kcalloc(regs_num, sizeof(*cfg), GFP_KERNEL);

	if (!cfg)

		return -ENOMEM;



	for (i = 0; i < regs_num; i++)

		cfg[i] = sprd_pll_read(pll, i);



	refin = pll_get_refin(pll);



	if (pinternal(pll, cfg, PLL_PREDIV))

		refin = refin * 2;



	if (pwidth(pll, PLL_POSTDIV) &&

	    ((pll->fflag == 1 && pinternal(pll, cfg, PLL_POSTDIV)) ||

	     (!pll->fflag && !pinternal(pll, cfg, PLL_POSTDIV))))

		refin = refin / 2;



	if (!pinternal(pll, cfg, PLL_DIV_S)) {

		rate = refin * pinternal_val(pll, cfg, PLL_N) * CLK_PLL_10M;

	} else {

		nint = pinternal_val(pll, cfg, PLL_NINT);

		if (pinternal(pll, cfg, PLL_SDM_EN))

			kint = pinternal_val(pll, cfg, PLL_KINT);



		mask = pmask(pll, PLL_KINT);



		k1 = pll->k1;

		k2 = pll->k2;

		rate = DIV_ROUND_CLOSEST_ULL(refin * kint * k1,

					 ((mask >> __ffs(mask)) + 1)) *

					 k2 + refin * nint * CLK_PLL_1M;

	}



	return rate;

}



#define SPRD_PLL_WRITE_CHECK(pll, i, mask, val)		\

	(((sprd_pll_read(pll, i) & mask) == val) ? 0 : (-EFAULT))



static int _sprd_pll_set_rate(const struct sprd_pll *pll,

			      unsigned long rate,

			      unsigned long parent_rate)

{

	struct reg_cfg *cfg;

	int ret = 0;

	u32 mask, shift, width, ibias_val, index;

	u32 regs_num = pll->regs_num, i = 0;

	unsigned long kint, nint;

	u64 tmp, refin, fvco = rate;



	cfg = kcalloc(regs_num, sizeof(*cfg), GFP_KERNEL);

	if (!cfg)

		return -ENOMEM;



	refin = pll_get_refin(pll);



	mask = pmask(pll, PLL_PREDIV);

	index = pindex(pll, PLL_PREDIV);

	width = pwidth(pll, PLL_PREDIV);

	if (width && (sprd_pll_read(pll, index) & mask))

		refin = refin * 2;



	mask = pmask(pll, PLL_POSTDIV);

	index = pindex(pll, PLL_POSTDIV);

	width = pwidth(pll, PLL_POSTDIV);

	cfg[index].msk = mask;

	if (width && ((pll->fflag == 1 && fvco <= pll->fvco) ||

		      (pll->fflag == 0 && fvco > pll->fvco)))

		cfg[index].val |= mask;



	if (width && fvco <= pll->fvco)

		fvco = fvco * 2;



	mask = pmask(pll, PLL_DIV_S);

	index = pindex(pll, PLL_DIV_S);

	cfg[index].val |= mask;

	cfg[index].msk |= mask;



	mask = pmask(pll, PLL_SDM_EN);

	index = pindex(pll, PLL_SDM_EN);

	cfg[index].val |= mask;

	cfg[index].msk |= mask;



	nint = do_div(fvco, refin * CLK_PLL_1M);

	mask = pmask(pll, PLL_NINT);

	index = pindex(pll, PLL_NINT);

	shift = pshift(pll, PLL_NINT);

	cfg[index].val |= (nint << shift) & mask;

	cfg[index].msk |= mask;



	mask = pmask(pll, PLL_KINT);

	index = pindex(pll, PLL_KINT);

	width = pwidth(pll, PLL_KINT);

	shift = pshift(pll, PLL_KINT);

	tmp = fvco - refin * nint * CLK_PLL_1M;

	tmp = do_div(tmp, 10000) * ((mask >> shift) + 1);

	kint = DIV_ROUND_CLOSEST_ULL(tmp, refin * 100);

	cfg[index].val |= (kint << shift) & mask;

	cfg[index].msk |= mask;



	ibias_val = pll_get_ibias(fvco, pll->itable);



	mask = pmask(pll, PLL_IBIAS);

	index = pindex(pll, PLL_IBIAS);

	shift = pshift(pll, PLL_IBIAS);

	cfg[index].val |= ibias_val << shift & mask;

	cfg[index].msk |= mask;



	for (i = 0; i < regs_num; i++) {

		if (cfg[i].msk) {

			sprd_pll_write(pll, i, cfg[i].msk, cfg[i].val);

			ret |= SPRD_PLL_WRITE_CHECK(pll, i, cfg[i].msk,

						   cfg[i].val);

		}

	}



	if (!ret)

		udelay(pll->udelay);



	return ret;

}



static unsigned long sprd_pll_recalc_rate(struct clk_hw *hw,

					  unsigned long parent_rate)

{

	struct sprd_pll *pll = hw_to_sprd_pll(hw);



	return _sprd_pll_recalc_rate(pll, parent_rate);

}



static int sprd_pll_set_rate(struct clk_hw *hw,

			     unsigned long rate,

			     unsigned long parent_rate)

{

	struct sprd_pll *pll = hw_to_sprd_pll(hw);



	return _sprd_pll_set_rate(pll, rate, parent_rate);

}



static int sprd_pll_clk_prepare(struct clk_hw *hw)

{

	struct sprd_pll *pll = hw_to_sprd_pll(hw);



	udelay(pll->udelay);



	return 0;

}



static long sprd_pll_round_rate(struct clk_hw *hw, unsigned long rate,

				unsigned long *prate)

{

	return rate;

}



const struct clk_ops sprd_pll_ops = {

	.prepare = sprd_pll_clk_prepare,

	.recalc_rate = sprd_pll_recalc_rate,

	.round_rate = sprd_pll_round_rate,

	.set_rate = sprd_pll_set_rate,

};

EXPORT_SYMBOL_GPL(sprd_pll_ops);

drivers/clk/sprd/pll.h

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// SPDX-License-Identifier: GPL-2.0

//

// Spreadtrum pll clock driver

//

// Copyright (C) 2015~2017 Spreadtrum, Inc.

// Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>



#ifndef _SPRD_PLL_H_

#define _SPRD_PLL_H_



#include "common.h"



struct reg_cfg {

	u32 val;

	u32 msk;

};



struct clk_bit_field {

	u8 shift;

	u8 width;

};



enum {

	PLL_LOCK_DONE,

	PLL_DIV_S,

	PLL_MOD_EN,

	PLL_SDM_EN,

	PLL_REFIN,

	PLL_IBIAS,

	PLL_N,

	PLL_NINT,

	PLL_KINT,

	PLL_PREDIV,

	PLL_POSTDIV,



	PLL_FACT_MAX

};



/*

 * struct sprd_pll - definition of adjustable pll clock

 *

 * @reg:	registers used to set the configuration of pll clock,

 *		reg[0] shows how many registers this pll clock uses.

 * @itable:	pll ibias table, itable[0] means how many items this

 *		table includes

 * @udelay	delay time after setting rate

 * @factors	used to calculate the pll clock rate

 * @fvco:	fvco threshold rate

 * @fflag:	fvco flag

 */

struct sprd_pll {

	u32 regs_num;

	const u64 *itable;

	const struct clk_bit_field *factors;

	u16 udelay;

	u16 k1;

	u16 k2;

	u16 fflag;

	u64 fvco;



	struct sprd_clk_common	common;

};



#define SPRD_PLL_WITH_ITABLE_K_FVCO(_struct, _name, _parent, _reg,	\

				    _regs_num, _itable, _factors,	\

				    _udelay, _k1, _k2, _fflag, _fvco)	\

	struct sprd_pll _struct = {					\

		.regs_num	= _regs_num,				\

		.itable		= _itable,				\

		.factors	= _factors,				\

		.udelay		= _udelay,				\

		.k1		= _k1,					\

		.k2		= _k2,					\

		.fflag		= _fflag,				\

		.fvco		= _fvco,				\

		.common		= {					\

			.regmap		= NULL,				\

			.reg		= _reg,				\

			.hw.init	= CLK_HW_INIT(_name,		\

						      _parent,		\

						      &sprd_pll_ops,	\

						      0),		\

		},							\

	}



#define SPRD_PLL_WITH_ITABLE_K(_struct, _name, _parent, _reg,		\

			       _regs_num, _itable, _factors,		\

			       _udelay, _k1, _k2)			\

	SPRD_PLL_WITH_ITABLE_K_FVCO(_struct, _name, _parent, _reg,	\

				    _regs_num, _itable, _factors,	\

				    _udelay, _k1, _k2, 0, 0)



#define SPRD_PLL_WITH_ITABLE_1K(_struct, _name, _parent, _reg,		\

				_regs_num, _itable, _factors, _udelay)	\

	SPRD_PLL_WITH_ITABLE_K_FVCO(_struct, _name, _parent, _reg,	\

				    _regs_num, _itable, _factors,	\

				    _udelay, 1000, 1000, 0, 0)



static inline struct sprd_pll *hw_to_sprd_pll(struct clk_hw *hw)

{

	struct sprd_clk_common *common = hw_to_sprd_clk_common(hw);



	return container_of(common, struct sprd_pll, common);

}



extern const struct clk_ops sprd_pll_ops;



#endif /* _SPRD_PLL_H_ */