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