clk: Add Fixed MMIO clock driver (50cc4caf) · Commits · 戴 / test

drivers/clk/Kconfig

+6 −0

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		@@ -290,6 +290,12 @@ config COMMON_CLK_BD718XX
		This driver supports ROHM BD71837 and ROHM BD71847
		PMICs clock gates.

		config COMMON_CLK_FIXED_MMIO
		bool "Clock driver for Memory Mapped Fixed values"
		depends on COMMON_CLK && OF
		help
		Support for Memory Mapped IO Fixed clocks

		source "drivers/clk/actions/Kconfig"
		source "drivers/clk/bcm/Kconfig"
		source "drivers/clk/hisilicon/Kconfig"

drivers/clk/Makefile

+1 −0

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		@@ -27,6 +27,7 @@ obj-$(CONFIG_COMMON_CLK_CDCE925) += clk-cdce925.o
		obj-$(CONFIG_ARCH_CLPS711X) += clk-clps711x.o
		obj-$(CONFIG_COMMON_CLK_CS2000_CP) += clk-cs2000-cp.o
		obj-$(CONFIG_ARCH_EFM32) += clk-efm32gg.o
		obj-$(CONFIG_COMMON_CLK_FIXED_MMIO) += clk-fixed-mmio.o
		obj-$(CONFIG_COMMON_CLK_GEMINI) += clk-gemini.o
		obj-$(CONFIG_COMMON_CLK_ASPEED) += clk-aspeed.o
		obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o

drivers/clk/clk-fixed-mmio.c

0 → 100644

+101 −0

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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/of_address.h>
		#include <linux/module.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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