// 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");