Jan Kotas | 50cc4ca | 2018-12-13 12:49:29 +0000 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| 3 | /* |
| 4 | * Memory Mapped IO Fixed clock driver |
| 5 | * |
| 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> |
Stephen Boyd | 62e59c4 | 2019-04-18 15:20:22 -0700 | [diff] [blame] | 13 | #include <linux/io.h> |
Jan Kotas | 50cc4ca | 2018-12-13 12:49:29 +0000 | [diff] [blame] | 14 | #include <linux/module.h> |
Stephen Boyd | 62e59c4 | 2019-04-18 15:20:22 -0700 | [diff] [blame] | 15 | #include <linux/of_address.h> |
Jan Kotas | 50cc4ca | 2018-12-13 12:49:29 +0000 | [diff] [blame] | 16 | #include <linux/platform_device.h> |
| 17 | |
| 18 | static 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 | |
| 52 | static void __init of_fixed_mmio_clk_setup(struct device_node *node) |
| 53 | { |
| 54 | fixed_mmio_clk_setup(node); |
| 55 | } |
| 56 | CLK_OF_DECLARE(fixed_mmio_clk, "fixed-mmio-clock", of_fixed_mmio_clk_setup); |
| 57 | |
Lee Jones | e28aa9b | 2021-01-26 12:45:33 +0000 | [diff] [blame] | 58 | /* |
Jan Kotas | 50cc4ca | 2018-12-13 12:49:29 +0000 | [diff] [blame] | 59 | * This is not executed when of_fixed_mmio_clk_setup succeeded. |
| 60 | */ |
| 61 | static 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 | |
Uwe Kleine-König | 6f149b6 | 2023-03-12 17:14:51 +0100 | [diff] [blame] | 74 | static void of_fixed_mmio_clk_remove(struct platform_device *pdev) |
Jan Kotas | 50cc4ca | 2018-12-13 12:49:29 +0000 | [diff] [blame] | 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); |
Jan Kotas | 50cc4ca | 2018-12-13 12:49:29 +0000 | [diff] [blame] | 80 | } |
| 81 | |
| 82 | static const struct of_device_id of_fixed_mmio_clk_ids[] = { |
| 83 | { .compatible = "fixed-mmio-clock" }, |
| 84 | { } |
| 85 | }; |
| 86 | MODULE_DEVICE_TABLE(of, of_fixed_mmio_clk_ids); |
| 87 | |
| 88 | static 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, |
Uwe Kleine-König | 6f149b6 | 2023-03-12 17:14:51 +0100 | [diff] [blame] | 94 | .remove_new = of_fixed_mmio_clk_remove, |
Jan Kotas | 50cc4ca | 2018-12-13 12:49:29 +0000 | [diff] [blame] | 95 | }; |
| 96 | module_platform_driver(of_fixed_mmio_clk_driver); |
| 97 | |
| 98 | MODULE_AUTHOR("Jan Kotas <jank@cadence.com>"); |
| 99 | MODULE_DESCRIPTION("Memory Mapped IO Fixed clock driver"); |