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 */
22static 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
30static 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	struct resource *r;
36	void __iomem *reg;
37	struct clk *clk;
38
39	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
40	reg = devm_ioremap_resource(&pdev->dev, r);
41	if (IS_ERR(reg))
42		return PTR_ERR(reg);
43
44	clk_parent = of_clk_get_parent_name(np, 0);
45	if (!clk_parent)
46		return -EINVAL;
47
48	of_property_read_string(np, "clock-output-names", &clk_name);
49
50	clk = clk_register_divider_table(&pdev->dev, clk_name, clk_parent,
51					 0, reg, 0, 2, 0, sun6i_a31_apb0_divs,
52					 NULL);
53	if (IS_ERR(clk))
54		return PTR_ERR(clk);
55
56	return of_clk_add_provider(np, of_clk_src_simple_get, clk);
57}
58
59static const struct of_device_id sun6i_a31_apb0_clk_dt_ids[] = {
60	{ .compatible = "allwinner,sun6i-a31-apb0-clk" },
61	{ /* sentinel */ }
62};
63
64static struct platform_driver sun6i_a31_apb0_clk_driver = {
65	.driver = {
66		.name = "sun6i-a31-apb0-clk",
67		.of_match_table = sun6i_a31_apb0_clk_dt_ids,
68	},
69	.probe = sun6i_a31_apb0_clk_probe,
70};
71builtin_platform_driver(sun6i_a31_apb0_clk_driver);