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/*
* Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
* Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
*
* 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.
*
* 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
*/
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)
{
return to_clk_fixed_rate(hw)->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);
/**
* clk_hw_register_fixed_rate_with_accuracy - register fixed-rate clock with
* the clock framework
* @dev: device that is registering this clock
* @name: name of this clock
* @parent_name: name of clock's parent
* @flags: framework-specific flags
* @fixed_rate: non-adjustable clock rate
* @fixed_accuracy: non-adjustable clock rate
*/
struct clk_hw *clk_hw_register_fixed_rate_with_accuracy(struct device *dev,
const char *name, const char *parent_name, unsigned long flags,
unsigned long fixed_rate, unsigned long fixed_accuracy)
{
struct clk_fixed_rate *fixed;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
/* 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 | CLK_IS_BASIC;
init.parent_names = (parent_name ? &parent_name: NULL);
init.num_parents = (parent_name ? 1 : 0);
/* struct clk_fixed_rate assignments */
fixed->fixed_rate = fixed_rate;
fixed->fixed_accuracy = fixed_accuracy;
fixed->hw.init = &init;
/* register the clock */
hw = &fixed->hw;
ret = clk_hw_register(dev, hw);
if (ret) {
kfree(fixed);
hw = ERR_PTR(ret);
}
return hw;
}
EXPORT_SYMBOL_GPL(clk_hw_register_fixed_rate_with_accuracy);
struct clk *clk_register_fixed_rate_with_accuracy(struct device *dev,
const char *name, const char *parent_name, unsigned long flags,
unsigned long fixed_rate, unsigned long fixed_accuracy)
{
struct clk_hw *hw;
hw = clk_hw_register_fixed_rate_with_accuracy(dev, name, parent_name,
flags, fixed_rate, fixed_accuracy);
if (IS_ERR(hw))
return ERR_CAST(hw);
return hw->clk;
}
EXPORT_SYMBOL_GPL(clk_register_fixed_rate_with_accuracy);
/**
* clk_hw_register_fixed_rate - register fixed-rate clock with the clock
* framework
* @dev: device that is registering this clock
* @name: name of this clock
* @parent_name: name of clock's parent
* @flags: framework-specific flags
* @fixed_rate: non-adjustable clock rate
*/
struct clk_hw *clk_hw_register_fixed_rate(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
unsigned long fixed_rate)
{
return clk_hw_register_fixed_rate_with_accuracy(dev, name, parent_name,
flags, fixed_rate, 0);
}
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)
{
return clk_register_fixed_rate_with_accuracy(dev, name, parent_name,
flags, fixed_rate, 0);
}
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 *_of_fixed_clk_setup(struct device_node *node)
{
struct clk *clk;
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);
clk = clk_register_fixed_rate_with_accuracy(NULL, clk_name, NULL,
0, rate, accuracy);
if (IS_ERR(clk))
return clk;
ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
if (ret) {
clk_unregister(clk);
return ERR_PTR(ret);
}
return clk;
}
/**
* of_fixed_clk_setup() - Setup function for simple fixed rate 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 *clk = platform_get_drvdata(pdev);
clk_unregister_fixed_rate(clk);
return 0;
}
static int of_fixed_clk_probe(struct platform_device *pdev)
{
struct clk *clk;
/*
* This function is not executed when of_fixed_clk_setup
* succeeded.
*/
clk = _of_fixed_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_clk_ids[] = {
{ .compatible = "fixed-clock" },
{ }
};
MODULE_DEVICE_TABLE(of, of_fixed_clk_ids);
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