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// SPDX-License-Identifier: GPL-2.0
/*
* Memory Mapped IO Fixed clock driver
*
* Copyright (C) 2018 Cadence Design Systems, Inc.
*
* Authors:
* Jan Kotas <jank@cadence.com>
*/
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
static struct clk_hw *fixed_mmio_clk_setup(struct device_node *node)
{
struct clk_hw *clk;
const char *clk_name = node->name;
void __iomem *base;
u32 freq;
int ret;
base = of_iomap(node, 0);
if (!base) {
pr_err("%pOFn: failed to map address\n", node);
return ERR_PTR(-EIO);
}
freq = readl(base);
iounmap(base);
of_property_read_string(node, "clock-output-names", &clk_name);
clk = clk_hw_register_fixed_rate(NULL, clk_name, NULL, 0, freq);
if (IS_ERR(clk)) {
pr_err("%pOFn: failed to register fixed rate clock\n", node);
return clk;
}
ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, clk);
if (ret) {
pr_err("%pOFn: failed to add clock provider\n", node);
clk_hw_unregister(clk);
clk = ERR_PTR(ret);
}
return clk;
}
static void __init of_fixed_mmio_clk_setup(struct device_node *node)
{
fixed_mmio_clk_setup(node);
}
CLK_OF_DECLARE(fixed_mmio_clk, "fixed-mmio-clock", of_fixed_mmio_clk_setup);
/*
* This is not executed when of_fixed_mmio_clk_setup succeeded.
*/
static int of_fixed_mmio_clk_probe(struct platform_device *pdev)
{
struct clk_hw *clk;
clk = fixed_mmio_clk_setup(pdev->dev.of_node);
if (IS_ERR(clk))
return PTR_ERR(clk);
platform_set_drvdata(pdev, clk);
return 0;
}
static int of_fixed_mmio_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_rate(clk);
return 0;
}
static const struct of_device_id of_fixed_mmio_clk_ids[] = {
{ .compatible = "fixed-mmio-clock" },
{ }
};
MODULE_DEVICE_TABLE(of, of_fixed_mmio_clk_ids);
static struct platform_driver of_fixed_mmio_clk_driver = {
.driver = {
.name = "of_fixed_mmio_clk",
.of_match_table = of_fixed_mmio_clk_ids,
},
.probe = of_fixed_mmio_clk_probe,
.remove = of_fixed_mmio_clk_remove,
};
module_platform_driver(of_fixed_mmio_clk_driver);
MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
MODULE_DESCRIPTION("Memory Mapped IO Fixed clock driver");
MODULE_LICENSE("GPL v2");
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