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50cc4caf JK |
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> | |
62e59c4e | 13 | #include <linux/io.h> |
50cc4caf | 14 | #include <linux/module.h> |
62e59c4e | 15 | #include <linux/of_address.h> |
50cc4caf JK |
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 | ||
e28aa9b0 | 58 | /* |
50cc4caf JK |
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 | ||
6f149b65 | 74 | static void of_fixed_mmio_clk_remove(struct platform_device *pdev) |
50cc4caf JK |
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); | |
50cc4caf JK |
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, | |
6f149b65 | 94 | .remove_new = of_fixed_mmio_clk_remove, |
50cc4caf JK |
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"); |