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/*
* 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,
};
struct clk_hw * __init
at91_clk_register_plldiv(struct regmap *regmap, const char *name,
const char *parent_name)
{
struct clk_plldiv *plldiv;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
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;
hw = &plldiv->hw;
ret = clk_hw_register(NULL, &plldiv->hw);
if (ret) {
kfree(plldiv);
hw = ERR_PTR(ret);
}
return hw;
}
static void __init
of_at91sam9x5_clk_plldiv_setup(struct device_node *np)
{
struct clk_hw *hw;
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;
hw = at91_clk_register_plldiv(regmap, name, parent_name);
if (IS_ERR(hw))
return;
of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
}
CLK_OF_DECLARE(at91sam9x5_clk_plldiv, "atmel,at91sam9x5-clk-plldiv",
of_at91sam9x5_clk_plldiv_setup);
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