clk-fixup-div.c
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/*
* Copyright (C) 2013 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-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "clk.h"
#define to_clk_div(_hw) container_of(_hw, struct clk_divider, hw)
#define div_mask(d) ((1 << (d->width)) - 1)
/**
* struct clk_fixup_div - imx integer fixup divider clock
* @divider: the parent class
* @ops: pointer to clk_ops of parent class
* @fixup: a hook to fixup the write value
*
* The imx fixup divider clock is a subclass of basic clk_divider
* with an addtional fixup hook.
*/
struct clk_fixup_div {
struct clk_divider divider;
const struct clk_ops *ops;
void (*fixup)(u32 *val);
};
static inline struct clk_fixup_div *to_clk_fixup_div(struct clk_hw *hw)
{
struct clk_divider *divider = to_clk_div(hw);
return container_of(divider, struct clk_fixup_div, divider);
}
static unsigned long clk_fixup_div_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_fixup_div *fixup_div = to_clk_fixup_div(hw);
return fixup_div->ops->recalc_rate(&fixup_div->divider.hw, parent_rate);
}
static long clk_fixup_div_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct clk_fixup_div *fixup_div = to_clk_fixup_div(hw);
return fixup_div->ops->round_rate(&fixup_div->divider.hw, rate, prate);
}
static int clk_fixup_div_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_fixup_div *fixup_div = to_clk_fixup_div(hw);
struct clk_divider *div = to_clk_div(hw);
unsigned int divider, value;
unsigned long flags = 0;
u32 val;
divider = parent_rate / rate;
/* Zero based divider */
value = divider - 1;
if (value > div_mask(div))
value = div_mask(div);
spin_lock_irqsave(div->lock, flags);
val = readl(div->reg);
val &= ~(div_mask(div) << div->shift);
val |= value << div->shift;
fixup_div->fixup(&val);
writel(val, div->reg);
spin_unlock_irqrestore(div->lock, flags);
return 0;
}
static const struct clk_ops clk_fixup_div_ops = {
.recalc_rate = clk_fixup_div_recalc_rate,
.round_rate = clk_fixup_div_round_rate,
.set_rate = clk_fixup_div_set_rate,
};
struct clk *imx_clk_fixup_divider(const char *name, const char *parent,
void __iomem *reg, u8 shift, u8 width,
void (*fixup)(u32 *val))
{
struct clk_fixup_div *fixup_div;
struct clk *clk;
struct clk_init_data init;
if (!fixup)
return ERR_PTR(-EINVAL);
fixup_div = kzalloc(sizeof(*fixup_div), GFP_KERNEL);
if (!fixup_div)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &clk_fixup_div_ops;
init.flags = CLK_SET_RATE_PARENT;
init.parent_names = parent ? &parent : NULL;
init.num_parents = parent ? 1 : 0;
fixup_div->divider.reg = reg;
fixup_div->divider.shift = shift;
fixup_div->divider.width = width;
fixup_div->divider.lock = &imx_ccm_lock;
fixup_div->divider.hw.init = &init;
fixup_div->ops = &clk_divider_ops;
fixup_div->fixup = fixup;
clk = clk_register(NULL, &fixup_div->divider.hw);
if (IS_ERR(clk))
kfree(fixup_div);
return clk;
}