// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
*/
#include <linux/module.h>
#include <linux/clk-provider.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/platform_device.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
*/
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);
unsigned long long int rate;
rate = (unsigned long long int)parent_rate * fix->mult;
do_div(rate, fix->div);
return (unsigned long)rate;
}
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_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
unsigned long best_parent;
best_parent = (rate / fix->mult) * fix->div;
*prate = clk_hw_round_rate(clk_hw_get_parent(hw), 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)
{
/*
* We must report success but we can do so unconditionally because
* clk_factor_round_rate returns values that ensure this call is a
* nop.
*/
return 0;
}
const 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);
static struct clk_hw *
__clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
const char *name, const char *parent_name, int index,
unsigned long flags, unsigned int mult, unsigned int div)
{
struct clk_fixed_factor *fix;
struct clk_init_data init = { };
struct clk_parent_data pdata = { .index = index };
struct clk_hw *hw;
int ret;
fix = kmalloc(sizeof(*fix), GFP_KERNEL);
if (!fix)
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;
if (parent_name)
init.parent_names = &parent_name;
else
init.parent_data = &pdata;
init.num_parents = 1;
hw = &fix->hw;
if (dev)
ret = clk_hw_register(dev, hw);
else
ret = of_clk_hw_register(np, hw);
if (ret) {
kfree(fix);
hw = ERR_PTR(ret);
}
return hw;
}
struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
const char *name, const char *parent_name, unsigned long flags,
unsigned int mult, unsigned int div)
{
return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, -1,
flags, mult, div);
}
EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
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_hw *hw;
hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult,
div);
if (IS_ERR(hw))
return ERR_CAST(hw);
return hw->clk;
}
EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
void clk_unregister_fixed_factor(struct clk *clk)
{
struct clk_hw *hw;
hw = __clk_get_hw(clk);
if (!hw)
return;
clk_unregister(clk);
kfree(to_clk_fixed_factor(hw));
}
EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
{
struct clk_fixed_factor *fix;
fix = to_clk_fixed_factor(hw);
clk_hw_unregister(hw);
kfree(fix);
}
EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
#ifdef [31mCONFIG_OF[0m
static const struct of_device_id set_rate_parent_matches[] = {
{ .compatible = "allwinner,sun4i-a10-pll3-2x-clk" },
{ /* Sentinel */ },
};
static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
{
struct clk_hw *hw;
const char *clk_name = node->name;
unsigned long flags = 0;
u32 div, mult;
int ret;
if (of_property_read_u32(node, "clock-div", &div)) {
pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n",
__func__, node);
return ERR_PTR(-EIO);
}
if (of_property_read_u32(node, "clock-mult", &mult)) {
pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n",
__func__, node);
return ERR_PTR(-EIO);
}
of_property_read_string(node, "clock-output-names", &clk_name);
if (of_match_node(set_rate_parent_matches, node))
flags |= CLK_SET_RATE_PARENT;
hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, 0,
flags, mult, div);
if (IS_ERR(hw)) {
/*
* Clear OF_POPULATED flag so that clock registration can be
* attempted again from probe function.
*/
of_node_clear_flag(node, OF_POPULATED);
return ERR_CAST(hw);
}
ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
if (ret) {
clk_hw_unregister_fixed_factor(hw);
return ERR_PTR(ret);
}
return hw;
}
/**
* of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
*/
void __init of_fixed_factor_clk_setup(struct device_node *node)
{
_of_fixed_factor_clk_setup(node);
}
CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
of_fixed_factor_clk_setup);
static int of_fixed_factor_clk_remove(struct platform_device *pdev)
{
struct clk_hw *clk = platform_get_drvdata(pdev);
of_clk_del_provider(pdev->dev.of_node);
clk_hw_unregister_fixed_factor(clk);
return 0;
}
static int of_fixed_factor_clk_probe(struct platform_device *pdev)
{
struct clk_hw *clk;
/*
* This function is not executed when of_fixed_factor_clk_setup
* succeeded.
*/
clk = _of_fixed_factor_clk_setup(pdev->dev.of_node);
if (IS_ERR(clk))
return PTR_ERR(clk);
platform_set_drvdata(pdev, clk);
return 0;
}
static const struct of_device_id of_fixed_factor_clk_ids[] = {
{ .compatible = "fixed-factor-clock" },
{ }
};
MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
static struct platform_driver of_fixed_factor_clk_driver = {
.driver = {
.name = "of_fixed_factor_clk",
.of_match_table = of_fixed_factor_clk_ids,
},
.probe = of_fixed_factor_clk_probe,
.remove = of_fixed_factor_clk_remove,
};
builtin_platform_driver(of_fixed_factor_clk_driver);
#endif