1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (C) 2014 Chen-Yu Tsai |
4 | * Author: Chen-Yu Tsai <wens@csie.org> |
5 | * |
6 | * Allwinner A23 APB0 clock driver |
7 | * |
8 | * Based on clk-sun6i-apb0.c |
9 | * Allwinner A31 APB0 clock driver |
10 | * |
11 | * Copyright (C) 2014 Free Electrons |
12 | * 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 | |
22 | static 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(np: node, index: 0); |
31 | if (!clk_parent) |
32 | return ERR_PTR(error: -EINVAL); |
33 | |
34 | of_property_read_string(np: node, propname: "clock-output-names" , out_string: &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(ptr: clk)) |
40 | return clk; |
41 | |
42 | ret = of_clk_add_provider(np: node, clk_src_get: of_clk_src_simple_get, data: clk); |
43 | if (ret) |
44 | goto err_unregister; |
45 | |
46 | return clk; |
47 | |
48 | err_unregister: |
49 | clk_unregister_divider(clk); |
50 | |
51 | return ERR_PTR(error: ret); |
52 | } |
53 | |
54 | static 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(device: node, index: 0, name: of_node_full_name(np: node)); |
61 | if (IS_ERR(ptr: reg)) { |
62 | /* |
63 | * This happens with clk nodes instantiated through mfd, |
64 | * as those do not have their resources assigned in the |
65 | * device tree. Do not print an error in this case. |
66 | */ |
67 | if (PTR_ERR(ptr: 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(ptr: clk)) |
75 | goto err_unmap; |
76 | |
77 | return; |
78 | |
79 | err_unmap: |
80 | iounmap(addr: reg); |
81 | of_address_to_resource(dev: node, index: 0, r: &res); |
82 | release_mem_region(res.start, resource_size(&res)); |
83 | } |
84 | CLK_OF_DECLARE_DRIVER(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk" , |
85 | sun8i_a23_apb0_setup); |
86 | |
87 | static 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, index: 0); |
94 | if (IS_ERR(ptr: reg)) |
95 | return PTR_ERR(ptr: reg); |
96 | |
97 | clk = sun8i_a23_apb0_register(node: np, reg); |
98 | return PTR_ERR_OR_ZERO(ptr: clk); |
99 | } |
100 | |
101 | static const struct of_device_id sun8i_a23_apb0_clk_dt_ids[] = { |
102 | { .compatible = "allwinner,sun8i-a23-apb0-clk" }, |
103 | { /* sentinel */ } |
104 | }; |
105 | |
106 | static 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 | }; |
113 | builtin_platform_driver(sun8i_a23_apb0_clk_driver); |
114 | |