1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (C) 2014 Free Electrons |
4 | * |
5 | * Author: Boris BREZILLON <boris.brezillon@free-electrons.com> |
6 | * |
7 | * Allwinner A31 APB0 clock driver |
8 | */ |
9 | |
10 | #include <linux/clk-provider.h> |
11 | #include <linux/init.h> |
12 | #include <linux/of.h> |
13 | #include <linux/platform_device.h> |
14 | |
15 | /* |
16 | * The APB0 clk has a configurable divisor. |
17 | * |
18 | * We must use a clk_div_table and not a regular power of 2 |
19 | * divisor here, because the first 2 values divide the clock |
20 | * by 2. |
21 | */ |
22 | static const struct clk_div_table sun6i_a31_apb0_divs[] = { |
23 | { .val = 0, .div = 2, }, |
24 | { .val = 1, .div = 2, }, |
25 | { .val = 2, .div = 4, }, |
26 | { .val = 3, .div = 8, }, |
27 | { /* sentinel */ }, |
28 | }; |
29 | |
30 | static int sun6i_a31_apb0_clk_probe(struct platform_device *pdev) |
31 | { |
32 | struct device_node *np = pdev->dev.of_node; |
33 | const char *clk_name = np->name; |
34 | const char *clk_parent; |
35 | void __iomem *reg; |
36 | struct clk *clk; |
37 | |
38 | reg = devm_platform_ioremap_resource(pdev, index: 0); |
39 | if (IS_ERR(ptr: reg)) |
40 | return PTR_ERR(ptr: reg); |
41 | |
42 | clk_parent = of_clk_get_parent_name(np, index: 0); |
43 | if (!clk_parent) |
44 | return -EINVAL; |
45 | |
46 | of_property_read_string(np, propname: "clock-output-names" , out_string: &clk_name); |
47 | |
48 | clk = clk_register_divider_table(dev: &pdev->dev, name: clk_name, parent_name: clk_parent, |
49 | flags: 0, reg, shift: 0, width: 2, clk_divider_flags: 0, table: sun6i_a31_apb0_divs, |
50 | NULL); |
51 | if (IS_ERR(ptr: clk)) |
52 | return PTR_ERR(ptr: clk); |
53 | |
54 | return of_clk_add_provider(np, clk_src_get: of_clk_src_simple_get, data: clk); |
55 | } |
56 | |
57 | static const struct of_device_id sun6i_a31_apb0_clk_dt_ids[] = { |
58 | { .compatible = "allwinner,sun6i-a31-apb0-clk" }, |
59 | { /* sentinel */ } |
60 | }; |
61 | |
62 | static struct platform_driver sun6i_a31_apb0_clk_driver = { |
63 | .driver = { |
64 | .name = "sun6i-a31-apb0-clk" , |
65 | .of_match_table = sun6i_a31_apb0_clk_dt_ids, |
66 | }, |
67 | .probe = sun6i_a31_apb0_clk_probe, |
68 | }; |
69 | builtin_platform_driver(sun6i_a31_apb0_clk_driver); |
70 | |