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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2014 Chen-Yu Tsai4 * Author: Chen-Yu Tsai <wens@csie.org>5 *6 * Allwinner A23 APB0 clock driver7 *8 * Based on clk-sun6i-apb0.c9 * Allwinner A31 APB0 clock driver10 *11 * Copyright (C) 2014 Free Electrons12 * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>13 */14 15#include <linux/clk-provider.h>16#include <linux/init.h>17#include <linux/io.h>18#include <linux/of.h>19#include <linux/of_address.h>20#include <linux/platform_device.h>21 22static struct clk *sun8i_a23_apb0_register(struct device_node *node,23 void __iomem *reg)24{25 const char *clk_name = node->name;26 const char *clk_parent;27 struct clk *clk;28 int ret;29 30 clk_parent = of_clk_get_parent_name(node, 0);31 if (!clk_parent)32 return ERR_PTR(-EINVAL);33 34 of_property_read_string(node, "clock-output-names", &clk_name);35 36 /* The A23 APB0 clock is a standard 2 bit wide divider clock */37 clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,38 0, 2, 0, NULL);39 if (IS_ERR(clk))40 return clk;41 42 ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);43 if (ret)44 goto err_unregister;45 46 return clk;47 48err_unregister:49 clk_unregister_divider(clk);50 51 return ERR_PTR(ret);52}53 54static void sun8i_a23_apb0_setup(struct device_node *node)55{56 void __iomem *reg;57 struct resource res;58 struct clk *clk;59 60 reg = of_io_request_and_map(node, 0, of_node_full_name(node));61 if (IS_ERR(reg)) {62 /*63 * This happens with clk nodes instantiated through mfd,64 * as those do not have their resources assigned in the65 * device tree. Do not print an error in this case.66 */67 if (PTR_ERR(reg) != -EINVAL)68 pr_err("Could not get registers for a23-apb0-clk\n");69 70 return;71 }72 73 clk = sun8i_a23_apb0_register(node, reg);74 if (IS_ERR(clk))75 goto err_unmap;76 77 return;78 79err_unmap:80 iounmap(reg);81 of_address_to_resource(node, 0, &res);82 release_mem_region(res.start, resource_size(&res));83}84CLK_OF_DECLARE_DRIVER(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",85 sun8i_a23_apb0_setup);86 87static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)88{89 struct device_node *np = pdev->dev.of_node;90 void __iomem *reg;91 struct clk *clk;92 93 reg = devm_platform_ioremap_resource(pdev, 0);94 if (IS_ERR(reg))95 return PTR_ERR(reg);96 97 clk = sun8i_a23_apb0_register(np, reg);98 return PTR_ERR_OR_ZERO(clk);99}100 101static const struct of_device_id sun8i_a23_apb0_clk_dt_ids[] = {102 { .compatible = "allwinner,sun8i-a23-apb0-clk" },103 { /* sentinel */ }104};105 106static struct platform_driver sun8i_a23_apb0_clk_driver = {107 .driver = {108 .name = "sun8i-a23-apb0-clk",109 .of_match_table = sun8i_a23_apb0_clk_dt_ids,110 },111 .probe = sun8i_a23_apb0_clk_probe,112};113builtin_platform_driver(sun8i_a23_apb0_clk_driver);114