original development tree for Linux kernel GTP module; now long in mainline.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
linux-gtp/drivers/clk/clk-fixed-factor.c

95 lines
2.4 KiB

/*
* 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;
}