1/*
2 * Copyright (C) 2014 Free Electrons
3 *
4 * License Terms: GNU General Public License v2
5 * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
6 *
7 * Allwinner A31 APB0 clock driver
8 *
9 */
10
11#include <linux/clk-provider.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/platform_device.h>
15
16/*
17 * The APB0 clk has a configurable divisor.
18 *
19 * We must use a clk_div_table and not a regular power of 2
20 * divisor here, because the first 2 values divide the clock
21 * by 2.
22 */
23static const struct clk_div_table sun6i_a31_apb0_divs[] = {
24	{ .val = 0, .div = 2, },
25	{ .val = 1, .div = 2, },
26	{ .val = 2, .div = 4, },
27	{ .val = 3, .div = 8, },
28	{ /* sentinel */ },
29};
30
31static int sun6i_a31_apb0_clk_probe(struct platform_device *pdev)
32{
33	struct device_node *np = pdev->dev.of_node;
34	const char *clk_name = np->name;
35	const char *clk_parent;
36	struct resource *r;
37	void __iomem *reg;
38	struct clk *clk;
39
40	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
41	reg = devm_ioremap_resource(&pdev->dev, r);
42	if (IS_ERR(reg))
43		return PTR_ERR(reg);
44
45	clk_parent = of_clk_get_parent_name(np, 0);
46	if (!clk_parent)
47		return -EINVAL;
48
49	of_property_read_string(np, "clock-output-names", &clk_name);
50
51	clk = clk_register_divider_table(&pdev->dev, clk_name, clk_parent,
52					 0, reg, 0, 2, 0, sun6i_a31_apb0_divs,
53					 NULL);
54	if (IS_ERR(clk))
55		return PTR_ERR(clk);
56
57	return of_clk_add_provider(np, of_clk_src_simple_get, clk);
58}
59
60static const struct of_device_id sun6i_a31_apb0_clk_dt_ids[] = {
61	{ .compatible = "allwinner,sun6i-a31-apb0-clk" },
62	{ /* sentinel */ }
63};
64
65static struct platform_driver sun6i_a31_apb0_clk_driver = {
66	.driver = {
67		.name = "sun6i-a31-apb0-clk",
68		.of_match_table = sun6i_a31_apb0_clk_dt_ids,
69	},
70	.probe = sun6i_a31_apb0_clk_probe,
71};
72module_platform_driver(sun6i_a31_apb0_clk_driver);
73
74MODULE_AUTHOR("Boris BREZILLON <boris.brezillon@free-electrons.com>");
75MODULE_DESCRIPTION("Allwinner A31 APB0 clock Driver");
76MODULE_LICENSE("GPL v2");
77