linux/drivers/clk/mxs/clk-div.c

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/*
* Copyright 2012 Freescale Semiconductor, Inc.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/slab.h>
#include "clk.h"
/**
* struct clk_div - mxs integer divider clock
* @divider: the parent class
* @ops: pointer to clk_ops of parent class
* @reg: register address
* @busy: busy bit shift
*
* The mxs divider clock is a subclass of basic clk_divider with an
* addtional busy bit.
*/
struct clk_div {
struct clk_divider divider;
const struct clk_ops *ops;
void __iomem *reg;
u8 busy;
};
static inline struct clk_div *to_clk_div(struct clk_hw *hw)
{
struct clk_divider *divider = container_of(hw, struct clk_divider, hw);
return container_of(divider, struct clk_div, divider);
}
static unsigned long clk_div_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_div *div = to_clk_div(hw);
return div->ops->recalc_rate(&div->divider.hw, parent_rate);
}
static long clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct clk_div *div = to_clk_div(hw);
return div->ops->round_rate(&div->divider.hw, rate, prate);
}
static int clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_div *div = to_clk_div(hw);
int ret;
ret = div->ops->set_rate(&div->divider.hw, rate, parent_rate);
if (!ret)
ret = mxs_clk_wait(div->reg, div->busy);
return ret;
}
static struct clk_ops clk_div_ops = {
.recalc_rate = clk_div_recalc_rate,
.round_rate = clk_div_round_rate,
.set_rate = clk_div_set_rate,
};
struct clk *mxs_clk_div(const char *name, const char *parent_name,
void __iomem *reg, u8 shift, u8 width, u8 busy)
{
struct clk_div *div;
struct clk *clk;
struct clk_init_data init;
div = kzalloc(sizeof(*div), GFP_KERNEL);
if (!div)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &clk_div_ops;
init.flags = CLK_SET_RATE_PARENT;
init.parent_names = (parent_name ? &parent_name: NULL);
init.num_parents = (parent_name ? 1 : 0);
div->reg = reg;
div->busy = busy;
div->divider.reg = reg;
div->divider.shift = shift;
div->divider.width = width;
div->divider.flags = CLK_DIVIDER_ONE_BASED;
div->divider.lock = &mxs_lock;
div->divider.hw.init = &init;
div->ops = &clk_divider_ops;
clk = clk_register(NULL, &div->divider.hw);
if (IS_ERR(clk))
kfree(div);
return clk;
}