96 lines
2.4 KiB
C
96 lines
2.4 KiB
C
|
/*
|
||
|
|
* Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License version 2 as
|
||
|
|
* published by the Free Software Foundation.
|
||
|
|
*
|
||
|
|
* Standard functionality for the common clock API.
|
||
|
|
*/
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/clk-provider.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
#include <linux/err.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* DOC: basic fixed multiplier and divider clock that cannot gate
|
||
|
|
*
|
||
|
|
* Traits of this clock:
|
||
|
|
* prepare - clk_prepare only ensures that parents are prepared
|
||
|
|
* enable - clk_enable only ensures that parents are enabled
|
||
|
|
* rate - rate is fixed. clk->rate = parent->rate / div * mult
|
||
|
|
* parent - fixed parent. No clk_set_parent support
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define to_clk_fixed_factor(_hw) container_of(_hw, struct clk_fixed_factor, hw)
|
||
|
|
|
||
|
|
static unsigned long clk_factor_recalc_rate(struct clk_hw *hw,
|
||
|
|
unsigned long parent_rate)
|
||
|
|
{
|
||
|
|
struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
|
||
|
|
|
||
|
|
return parent_rate * fix->mult / fix->div;
|
||
|
|
}
|
||
|
|
|
||
|
|
static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate,
|
||
|
|
unsigned long *prate)
|
||
|
|
{
|
||
|
|
struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
|
||
|
|
|
||
|
|
if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) {
|
||
|
|
unsigned long best_parent;
|
||
|
|
|
||
|
|
best_parent = (rate / fix->mult) * fix->div;
|
||
|
|
*prate = __clk_round_rate(__clk_get_parent(hw->clk),
|
||
|
|
best_parent);
|
||
|
|
}
|
||
|
|
|
||
|
|
return (*prate / fix->div) * fix->mult;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
|
||
|
|
unsigned long parent_rate)
|
||
|
|
{
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
struct clk_ops clk_fixed_factor_ops = {
|
||
|
|
.round_rate = clk_factor_round_rate,
|
||
|
|
.set_rate = clk_factor_set_rate,
|
||
|
|
.recalc_rate = clk_factor_recalc_rate,
|
||
|
|
};
|
||
|
|
EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
|
||
|
|
|
||
|
|
struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
|
||
|
|
const char *parent_name, unsigned long flags,
|
||
|
|
unsigned int mult, unsigned int div)
|
||
|
|
{
|
||
|
|
struct clk_fixed_factor *fix;
|
||
|
|
struct clk_init_data init;
|
||
|
|
struct clk *clk;
|
||
|
|
|
||
|
|
fix = kmalloc(sizeof(*fix), GFP_KERNEL);
|
||
|
|
if (!fix) {
|
||
|
|
pr_err("%s: could not allocate fixed factor clk\n", __func__);
|
||
|
|
return ERR_PTR(-ENOMEM);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* struct clk_fixed_factor assignments */
|
||
|
|
fix->mult = mult;
|
||
|
|
fix->div = div;
|
||
|
|
fix->hw.init = &init;
|
||
|
|
|
||
|
|
init.name = name;
|
||
|
|
init.ops = &clk_fixed_factor_ops;
|
||
|
|
init.flags = flags;
|
||
|
|
init.parent_names = &parent_name;
|
||
|
|
init.num_parents = 1;
|
||
|
|
|
||
|
|
clk = clk_register(dev, &fix->hw);
|
||
|
|
|
||
|
|
if (IS_ERR(clk))
|
||
|
|
kfree(fix);
|
||
|
|
|
||
|
|
return clk;
|
||
|
|
}
|