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1// SPDX-License-Identifier: GPL-2.02 3/*4 * Memory Mapped IO Fixed clock driver5 *6 * Copyright (C) 2018 Cadence Design Systems, Inc.7 *8 * Authors:9 * Jan Kotas <jank@cadence.com>10 */11 12#include <linux/clk-provider.h>13#include <linux/io.h>14#include <linux/module.h>15#include <linux/of_address.h>16#include <linux/platform_device.h>17 18static struct clk_hw *fixed_mmio_clk_setup(struct device_node *node)19{20 struct clk_hw *clk;21 const char *clk_name = node->name;22 void __iomem *base;23 u32 freq;24 int ret;25 26 base = of_iomap(node, 0);27 if (!base) {28 pr_err("%pOFn: failed to map address\n", node);29 return ERR_PTR(-EIO);30 }31 32 freq = readl(base);33 iounmap(base);34 of_property_read_string(node, "clock-output-names", &clk_name);35 36 clk = clk_hw_register_fixed_rate(NULL, clk_name, NULL, 0, freq);37 if (IS_ERR(clk)) {38 pr_err("%pOFn: failed to register fixed rate clock\n", node);39 return clk;40 }41 42 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, clk);43 if (ret) {44 pr_err("%pOFn: failed to add clock provider\n", node);45 clk_hw_unregister(clk);46 clk = ERR_PTR(ret);47 }48 49 return clk;50}51 52static void __init of_fixed_mmio_clk_setup(struct device_node *node)53{54 fixed_mmio_clk_setup(node);55}56CLK_OF_DECLARE(fixed_mmio_clk, "fixed-mmio-clock", of_fixed_mmio_clk_setup);57 58/*59 * This is not executed when of_fixed_mmio_clk_setup succeeded.60 */61static int of_fixed_mmio_clk_probe(struct platform_device *pdev)62{63 struct clk_hw *clk;64 65 clk = fixed_mmio_clk_setup(pdev->dev.of_node);66 if (IS_ERR(clk))67 return PTR_ERR(clk);68 69 platform_set_drvdata(pdev, clk);70 71 return 0;72}73 74static void of_fixed_mmio_clk_remove(struct platform_device *pdev)75{76 struct clk_hw *clk = platform_get_drvdata(pdev);77 78 of_clk_del_provider(pdev->dev.of_node);79 clk_hw_unregister_fixed_rate(clk);80}81 82static const struct of_device_id of_fixed_mmio_clk_ids[] = {83 { .compatible = "fixed-mmio-clock" },84 { }85};86MODULE_DEVICE_TABLE(of, of_fixed_mmio_clk_ids);87 88static struct platform_driver of_fixed_mmio_clk_driver = {89 .driver = {90 .name = "of_fixed_mmio_clk",91 .of_match_table = of_fixed_mmio_clk_ids,92 },93 .probe = of_fixed_mmio_clk_probe,94 .remove = of_fixed_mmio_clk_remove,95};96module_platform_driver(of_fixed_mmio_clk_driver);97 98MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");99MODULE_DESCRIPTION("Memory Mapped IO Fixed clock driver");100