1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Marvell Armada 37xx SoC xtal clocks
4 *
5 * Copyright (C) 2016 Marvell
6 *
7 * Gregory CLEMENT <gregory.clement@free-electrons.com>
8 *
9 */
10
11#include <linux/clk-provider.h>
12#include <linux/mfd/syscon.h>
13#include <linux/platform_device.h>
14#include <linux/regmap.h>
15
16#define NB_GPIO1_LATCH	0x8
17#define XTAL_MODE	    BIT(9)
18
19static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
20{
21	struct device_node *np = pdev->dev.of_node;
22	const char *xtal_name = "xtal";
23	struct device_node *parent;
24	struct regmap *regmap;
25	struct clk_hw *xtal_hw;
26	unsigned int rate;
27	u32 reg;
28	int ret;
29
30	xtal_hw = devm_kzalloc(&pdev->dev, sizeof(*xtal_hw), GFP_KERNEL);
31	if (!xtal_hw)
32		return -ENOMEM;
33
34	platform_set_drvdata(pdev, xtal_hw);
35
36	parent = np->parent;
37	if (!parent) {
38		dev_err(&pdev->dev, "no parent\n");
39		return -ENODEV;
40	}
41
42	regmap = syscon_node_to_regmap(parent);
43	if (IS_ERR(regmap)) {
44		dev_err(&pdev->dev, "cannot get regmap\n");
45		return PTR_ERR(regmap);
46	}
47
48	ret = regmap_read(regmap, NB_GPIO1_LATCH, &reg);
49	if (ret) {
50		dev_err(&pdev->dev, "cannot read from regmap\n");
51		return ret;
52	}
53
54	if (reg & XTAL_MODE)
55		rate = 40000000;
56	else
57		rate = 25000000;
58
59	of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
60	xtal_hw = clk_hw_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);
61	if (IS_ERR(xtal_hw))
62		return PTR_ERR(xtal_hw);
63	ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, xtal_hw);
64
65	return ret;
66}
67
68static int armada_3700_xtal_clock_remove(struct platform_device *pdev)
69{
70	of_clk_del_provider(pdev->dev.of_node);
71
72	return 0;
73}
74
75static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
76	{ .compatible = "marvell,armada-3700-xtal-clock", },
77	{ }
78};
79
80static struct platform_driver armada_3700_xtal_clock_driver = {
81	.probe = armada_3700_xtal_clock_probe,
82	.remove = armada_3700_xtal_clock_remove,
83	.driver		= {
84		.name	= "marvell-armada-3700-xtal-clock",
85		.of_match_table = armada_3700_xtal_clock_of_match,
86	},
87};
88
89builtin_platform_driver(armada_3700_xtal_clock_driver);
90