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/*
* clk-fixed-factor.c - generic barebox clock support. Based on Linux clk support
*
* Copyright (c) 2012 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <common.h>
#include <io.h>
#include <malloc.h>
#include <linux/clk.h>
#include <linux/err.h>
struct clk_fixed_factor {
struct clk clk;
int mult;
int div;
const char *parent;
};
static unsigned long clk_fixed_factor_recalc_rate(struct clk *clk,
unsigned long parent_rate)
{
struct clk_fixed_factor *f = container_of(clk, struct clk_fixed_factor, clk);
return (parent_rate / f->div) * f->mult;
}
static long clk_factor_round_rate(struct clk *clk, unsigned long rate,
unsigned long *prate)
{
struct clk_fixed_factor *fix = container_of(clk, struct clk_fixed_factor, clk);
if (clk->flags & CLK_SET_RATE_PARENT) {
unsigned long best_parent;
best_parent = (rate / fix->mult) * fix->div;
*prate = clk_round_rate(clk_get_parent(clk), best_parent);
}
return (*prate / fix->div) * fix->mult;
}
static int clk_factor_set_rate(struct clk *clk, unsigned long rate,
unsigned long parent_rate)
{
struct clk_fixed_factor *fix = container_of(clk, struct clk_fixed_factor, clk);
if (clk->flags & CLK_SET_RATE_PARENT) {
return clk_set_rate(clk_get_parent(clk), rate * fix->div / fix->mult);
}
return 0;
}
static struct clk_ops clk_fixed_factor_ops = {
.set_rate = clk_factor_set_rate,
.round_rate = clk_factor_round_rate,
.recalc_rate = clk_fixed_factor_recalc_rate,
};
struct clk *clk_fixed_factor(const char *name,
const char *parent, unsigned int mult, unsigned int div, unsigned flags)
{
struct clk_fixed_factor *f = xzalloc(sizeof(*f));
int ret;
f->mult = mult;
f->div = div;
f->parent = parent;
f->clk.ops = &clk_fixed_factor_ops;
f->clk.name = name;
f->clk.flags = flags;
f->clk.parent_names = &f->parent;
f->clk.num_parents = 1;
ret = clk_register(&f->clk);
if (ret) {
free(f);
return ERR_PTR(ret);
}
return &f->clk;
}
/**
* of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
*/
static int of_fixed_factor_clk_setup(struct device_node *node)
{
struct clk *clk;
const char *clk_name = node->name;
const char *parent_name;
u32 div, mult;
if (of_property_read_u32(node, "clock-div", &div)) {
pr_err("%s Fixed factor clock <%s> must have a clock-div property\n",
__func__, node->name);
return -EINVAL;
}
if (of_property_read_u32(node, "clock-mult", &mult)) {
pr_err("%s Fixed factor clock <%s> must have a clock-mult property\n",
__func__, node->name);
return -EINVAL;
}
of_property_read_string(node, "clock-output-names", &clk_name);
parent_name = of_clk_get_parent_name(node, 0);
clk = clk_fixed_factor(clk_name, parent_name, mult, div, 0);
if (IS_ERR(clk))
return IS_ERR(clk);
return of_clk_add_provider(node, of_clk_src_simple_get, clk);
}
CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
of_fixed_factor_clk_setup);
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