[deliverable/linux.git] / drivers / clk / at91 / clk-plldiv.c

/*
 *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.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; either version 2 of the License, or
 * (at your option) any later version.
 *
 */

#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/of.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>

#include "pmc.h"

#define to_clk_plldiv(hw) container_of(hw, struct clk_plldiv, hw)

struct clk_plldiv {
	struct clk_hw hw;
	struct regmap *regmap;
};

static unsigned long clk_plldiv_recalc_rate(struct clk_hw *hw,
					    unsigned long parent_rate)
{
	struct clk_plldiv *plldiv = to_clk_plldiv(hw);
	unsigned int mckr;

	regmap_read(plldiv->regmap, AT91_PMC_MCKR, &mckr);

	if (mckr & AT91_PMC_PLLADIV2)
		return parent_rate / 2;

	return parent_rate;
}

static long clk_plldiv_round_rate(struct clk_hw *hw, unsigned long rate,
					unsigned long *parent_rate)
{
	unsigned long div;

	if (rate > *parent_rate)
		return *parent_rate;
	div = *parent_rate / 2;
	if (rate < div)
		return div;

	if (rate - div < *parent_rate - rate)
		return div;

	return *parent_rate;
}

static int clk_plldiv_set_rate(struct clk_hw *hw, unsigned long rate,
			       unsigned long parent_rate)
{
	struct clk_plldiv *plldiv = to_clk_plldiv(hw);

	if ((parent_rate != rate) && (parent_rate / 2 != rate))
		return -EINVAL;

	regmap_update_bits(plldiv->regmap, AT91_PMC_MCKR, AT91_PMC_PLLADIV2,
			   parent_rate != rate ? AT91_PMC_PLLADIV2 : 0);

	return 0;
}

static const struct clk_ops plldiv_ops = {
	.recalc_rate = clk_plldiv_recalc_rate,
	.round_rate = clk_plldiv_round_rate,
	.set_rate = clk_plldiv_set_rate,
};

static struct clk * __init
at91_clk_register_plldiv(struct regmap *regmap, const char *name,
			 const char *parent_name)
{
	struct clk_plldiv *plldiv;
	struct clk *clk = NULL;
	struct clk_init_data init;

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

	init.name = name;
	init.ops = &plldiv_ops;
	init.parent_names = parent_name ? &parent_name : NULL;
	init.num_parents = parent_name ? 1 : 0;
	init.flags = CLK_SET_RATE_GATE;

	plldiv->hw.init = &init;
	plldiv->regmap = regmap;

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

	if (IS_ERR(clk))
		kfree(plldiv);

	return clk;
}

static void __init
of_at91sam9x5_clk_plldiv_setup(struct device_node *np)
{
	struct clk *clk;
	const char *parent_name;
	const char *name = np->name;
	struct regmap *regmap;

	parent_name = of_clk_get_parent_name(np, 0);

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

	regmap = syscon_node_to_regmap(of_get_parent(np));
	if (IS_ERR(regmap))
		return;

	clk = at91_clk_register_plldiv(regmap, name, parent_name);
	if (IS_ERR(clk))
		return;

	of_clk_add_provider(np, of_clk_src_simple_get, clk);
	return;
}
CLK_OF_DECLARE(at91sam9x5_clk_plldiv, "atmel,at91sam9x5-clk-plldiv",
	       of_at91sam9x5_clk_plldiv_setup);
Commit	Line	Data
1a748d2b BB	1	/*
	2	* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	*/
	10
	11	#include <linux/clk-provider.h>
	12	#include <linux/clkdev.h>
	13	#include <linux/clk/at91_pmc.h>
	14	#include <linux/of.h>
1bdf0232 BB	15	#include <linux/mfd/syscon.h>
1bdf0232 BB	16	#include <linux/regmap.h>
1a748d2b BB	17
	18	#include "pmc.h"
	19
	20	#define to_clk_plldiv(hw) container_of(hw, struct clk_plldiv, hw)
	21
	22	struct clk_plldiv {
	23	struct clk_hw hw;
1bdf0232	24	struct regmap *regmap;
1a748d2b BB	25	};
	26
	27	static unsigned long clk_plldiv_recalc_rate(struct clk_hw *hw,
	28	unsigned long parent_rate)
	29	{
	30	struct clk_plldiv *plldiv = to_clk_plldiv(hw);
1bdf0232	31	unsigned int mckr;
1a748d2b	32
1bdf0232 BB	33	regmap_read(plldiv->regmap, AT91_PMC_MCKR, &mckr);
	34
	35	if (mckr & AT91_PMC_PLLADIV2)
1a748d2b BB	36	return parent_rate / 2;
	37
	38	return parent_rate;
	39	}
	40
	41	static long clk_plldiv_round_rate(struct clk_hw *hw, unsigned long rate,
	42	unsigned long *parent_rate)
	43	{
	44	unsigned long div;
	45
	46	if (rate > *parent_rate)
	47	return *parent_rate;
	48	div = *parent_rate / 2;
	49	if (rate < div)
	50	return div;
	51
	52	if (rate - div < *parent_rate - rate)
	53	return div;
	54
	55	return *parent_rate;
	56	}
	57
	58	static int clk_plldiv_set_rate(struct clk_hw *hw, unsigned long rate,
	59	unsigned long parent_rate)
	60	{
	61	struct clk_plldiv *plldiv = to_clk_plldiv(hw);
1a748d2b	62
1bdf0232	63	if ((parent_rate != rate) && (parent_rate / 2 != rate))
1a748d2b BB	64	return -EINVAL;
1a748d2b BB	65
1bdf0232 BB	66	regmap_update_bits(plldiv->regmap, AT91_PMC_MCKR, AT91_PMC_PLLADIV2,
1bdf0232 BB	67	parent_rate != rate ? AT91_PMC_PLLADIV2 : 0);
1a748d2b BB	68
	69	return 0;
	70	}
	71
	72	static const struct clk_ops plldiv_ops = {
	73	.recalc_rate = clk_plldiv_recalc_rate,
	74	.round_rate = clk_plldiv_round_rate,
	75	.set_rate = clk_plldiv_set_rate,
	76	};
	77
	78	static struct clk * __init
1bdf0232	79	at91_clk_register_plldiv(struct regmap regmap, const char name,
1a748d2b BB	80	const char *parent_name)
	81	{
	82	struct clk_plldiv *plldiv;
	83	struct clk *clk = NULL;
	84	struct clk_init_data init;
	85
	86	plldiv = kzalloc(sizeof(*plldiv), GFP_KERNEL);
	87	if (!plldiv)
	88	return ERR_PTR(-ENOMEM);
	89
	90	init.name = name;
	91	init.ops = &plldiv_ops;
	92	init.parent_names = parent_name ? &parent_name : NULL;
	93	init.num_parents = parent_name ? 1 : 0;
	94	init.flags = CLK_SET_RATE_GATE;
	95
	96	plldiv->hw.init = &init;
1bdf0232	97	plldiv->regmap = regmap;
1a748d2b BB	98
	99	clk = clk_register(NULL, &plldiv->hw);
	100
	101	if (IS_ERR(clk))
	102	kfree(plldiv);
	103
	104	return clk;
	105	}
	106
	107	static void __init
1bdf0232	108	of_at91sam9x5_clk_plldiv_setup(struct device_node *np)
1a748d2b BB	109	{
	110	struct clk *clk;
	111	const char *parent_name;
	112	const char *name = np->name;
1bdf0232	113	struct regmap *regmap;
1a748d2b BB	114
	115	parent_name = of_clk_get_parent_name(np, 0);
	116
	117	of_property_read_string(np, "clock-output-names", &name);
	118
1bdf0232 BB	119	regmap = syscon_node_to_regmap(of_get_parent(np));
	120	if (IS_ERR(regmap))
	121	return;
1a748d2b	122
1bdf0232	123	clk = at91_clk_register_plldiv(regmap, name, parent_name);
1a748d2b BB	124	if (IS_ERR(clk))
	125	return;
	126
	127	of_clk_add_provider(np, of_clk_src_simple_get, clk);
	128	return;
	129	}
1bdf0232 BB	130	CLK_OF_DECLARE(at91sam9x5_clk_plldiv, "atmel,at91sam9x5-clk-plldiv",
1bdf0232 BB	131	of_at91sam9x5_clk_plldiv_setup);