1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *
4 * Copyright (C) 2012 ARM Limited
5 */
6
7#include <linux/clkdev.h>
8#include <linux/clk-provider.h>
9#include <linux/err.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/slab.h>
14#include <linux/vexpress.h>
15
16struct vexpress_osc {
17	struct regmap *reg;
18	struct clk_hw hw;
19	unsigned long rate_min;
20	unsigned long rate_max;
21};
22
23#define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw)
24
25static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw,
26		unsigned long parent_rate)
27{
28	struct vexpress_osc *osc = to_vexpress_osc(hw);
29	u32 rate;
30
31	regmap_read(osc->reg, 0, &rate);
32
33	return rate;
34}
35
36static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate,
37		unsigned long *parent_rate)
38{
39	struct vexpress_osc *osc = to_vexpress_osc(hw);
40
41	if (osc->rate_min && rate < osc->rate_min)
42		rate = osc->rate_min;
43
44	if (osc->rate_max && rate > osc->rate_max)
45		rate = osc->rate_max;
46
47	return rate;
48}
49
50static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate,
51		unsigned long parent_rate)
52{
53	struct vexpress_osc *osc = to_vexpress_osc(hw);
54
55	return regmap_write(osc->reg, 0, rate);
56}
57
58static const struct clk_ops vexpress_osc_ops = {
59	.recalc_rate = vexpress_osc_recalc_rate,
60	.round_rate = vexpress_osc_round_rate,
61	.set_rate = vexpress_osc_set_rate,
62};
63
64
65static int vexpress_osc_probe(struct platform_device *pdev)
66{
67	struct clk_init_data init;
68	struct vexpress_osc *osc;
69	u32 range[2];
70	int ret;
71
72	osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL);
73	if (!osc)
74		return -ENOMEM;
75
76	osc->reg = devm_regmap_init_vexpress_config(&pdev->dev);
77	if (IS_ERR(osc->reg))
78		return PTR_ERR(osc->reg);
79
80	if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range,
81			ARRAY_SIZE(range)) == 0) {
82		osc->rate_min = range[0];
83		osc->rate_max = range[1];
84	}
85
86	if (of_property_read_string(pdev->dev.of_node, "clock-output-names",
87			&init.name) != 0)
88		init.name = dev_name(&pdev->dev);
89
90	init.ops = &vexpress_osc_ops;
91	init.flags = 0;
92	init.num_parents = 0;
93
94	osc->hw.init = &init;
95
96	ret = devm_clk_hw_register(&pdev->dev, &osc->hw);
97	if (ret < 0)
98		return ret;
99
100	devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get, &osc->hw);
101	clk_hw_set_rate_range(&osc->hw, osc->rate_min, osc->rate_max);
102
103	dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name);
104
105	return 0;
106}
107
108static const struct of_device_id vexpress_osc_of_match[] = {
109	{ .compatible = "arm,vexpress-osc", },
110	{}
111};
112MODULE_DEVICE_TABLE(of, vexpress_osc_of_match);
113
114static struct platform_driver vexpress_osc_driver = {
115	.driver	= {
116		.name = "vexpress-osc",
117		.of_match_table = vexpress_osc_of_match,
118	},
119	.probe = vexpress_osc_probe,
120};
121module_platform_driver(vexpress_osc_driver);
122MODULE_LICENSE("GPL v2");
123