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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
* Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
*
* Fixed rate clock implementation
*/
#include <linux/clk-provider.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/platform_device.h>
/*
* DOC: basic fixed-rate clock that cannot gate
*
* Traits of this clock:
* prepare - clk_(un)prepare only ensures parents are prepared
* enable - clk_enable only ensures parents are enabled
* rate - rate is always a fixed value. No clk_set_rate support
* parent - fixed parent. No clk_set_parent support
*/
#define to_clk_fixed_rate(_hw) container_of(_hw, struct clk_fixed_rate, hw)
static unsigned long clk_fixed_rate_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
return to_clk_fixed_rate(hw)->fixed_rate;
}
static unsigned long clk_fixed_rate_recalc_accuracy(struct clk_hw *hw,
unsigned long parent_accuracy)
{
struct clk_fixed_rate *fixed = to_clk_fixed_rate(hw);
if (fixed->flags & CLK_FIXED_RATE_PARENT_ACCURACY)
return parent_accuracy;
return fixed->fixed_accuracy;
}
const struct clk_ops clk_fixed_rate_ops = {
.recalc_rate = clk_fixed_rate_recalc_rate,
.recalc_accuracy = clk_fixed_rate_recalc_accuracy,
};
EXPORT_SYMBOL_GPL(clk_fixed_rate_ops);
struct clk_hw *__clk_hw_register_fixed_rate(struct device *dev,
struct device_node *np, const char *name,
const char *parent_name, const struct clk_hw *parent_hw,
const struct clk_parent_data *parent_data, unsigned long flags,
unsigned long fixed_rate, unsigned long fixed_accuracy,
unsigned long clk_fixed_flags)
{
struct clk_fixed_rate *fixed;
struct clk_hw *hw;
struct clk_init_data init = {};
int ret = -EINVAL;
/* allocate fixed-rate clock */
fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
if (!fixed)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &clk_fixed_rate_ops;
init.flags = flags;
init.parent_names = parent_name ? &parent_name : NULL;
init.parent_hws = parent_hw ? &parent_hw : NULL;
init.parent_data = parent_data;
if (parent_name || parent_hw || parent_data)
init.num_parents = 1;
else
init.num_parents = 0;
/* struct clk_fixed_rate assignments */
fixed->flags = clk_fixed_flags;
fixed->fixed_rate = fixed_rate;
fixed->fixed_accuracy = fixed_accuracy;
fixed->hw.init = &init;
/* register the clock */
hw = &fixed->hw;
if (dev || !np)
ret = clk_hw_register(dev, hw);
else if (np)
ret = of_clk_hw_register(np, hw);
if (ret) {
kfree(fixed);
hw = ERR_PTR(ret);
}
return hw;
}
EXPORT_SYMBOL_GPL(__clk_hw_register_fixed_rate);
struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
unsigned long fixed_rate)
{
struct clk_hw *hw;
hw = clk_hw_register_fixed_rate_with_accuracy(dev, name, parent_name,
flags, fixed_rate, 0);
if (IS_ERR(hw))
return ERR_CAST(hw);
return hw->clk;
}
EXPORT_SYMBOL_GPL(clk_register_fixed_rate);
void clk_unregister_fixed_rate(struct clk *clk)
{
struct clk_hw *hw;
hw = __clk_get_hw(clk);
if (!hw)
return;
clk_unregister(clk);
kfree(to_clk_fixed_rate(hw));
}
EXPORT_SYMBOL_GPL(clk_unregister_fixed_rate);
void clk_hw_unregister_fixed_rate(struct clk_hw *hw)
{
struct clk_fixed_rate *fixed;
fixed = to_clk_fixed_rate(hw);
clk_hw_unregister(hw);
kfree(fixed);
}
EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_rate);
#ifdef CONFIG_OF
static struct clk_hw *_of_fixed_clk_setup(struct device_node *node)
{
struct clk_hw *hw;
const char *clk_name = node->name;
u32 rate;
u32 accuracy = 0;
int ret;
if (of_property_read_u32(node, "clock-frequency", &rate))
return ERR_PTR(-EIO);
of_property_read_u32(node, "clock-accuracy", &accuracy);
of_property_read_string(node, "clock-output-names", &clk_name);
hw = clk_hw_register_fixed_rate_with_accuracy(NULL, clk_name, NULL,
0, rate, accuracy);
if (IS_ERR(hw))
return hw;
ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
if (ret) {
clk_hw_unregister_fixed_rate(hw);
return ERR_PTR(ret);
}
return hw;
}
/**
* of_fixed_clk_setup() - Setup function for simple fixed rate clock
* @node: device node for the clock
*/
void __init of_fixed_clk_setup(struct device_node *node)
{
_of_fixed_clk_setup(node);
}
CLK_OF_DECLARE(fixed_clk, "fixed-clock", of_fixed_clk_setup);
static int of_fixed_clk_remove(struct platform_device *pdev)
{
struct clk_hw *hw = platform_get_drvdata(pdev);
of_clk_del_provider(pdev->dev.of_node);
clk_hw_unregister_fixed_rate(hw);
return 0;
}
static int of_fixed_clk_probe(struct platform_device *pdev)
{
struct clk_hw *hw;
/*
* This function is not executed when of_fixed_clk_setup
* succeeded.
*/
hw = _of_fixed_clk_setup(pdev->dev.of_node);
if (IS_ERR(hw))
return PTR_ERR(hw);
platform_set_drvdata(pdev, hw);
return 0;
}
static const struct of_device_id of_fixed_clk_ids[] = {
{ .compatible = "fixed-clock" },
{ }
};
static struct platform_driver of_fixed_clk_driver = {
.driver = {
.name = "of_fixed_clk",
.of_match_table = of_fixed_clk_ids,
},
.probe = of_fixed_clk_probe,
.remove = of_fixed_clk_remove,
};
builtin_platform_driver(of_fixed_clk_driver);
#endif
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