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7#include <linux/clkdev.h>
8#include <linux/clk-provider.h>
9#include <linux/err.h>
10#include <linux/of.h>
11#include <linux/platform_device.h>
12#include <linux/slab.h>
13#include <linux/vexpress.h>
14
15struct vexpress_osc {
16 struct regmap *reg;
17 struct clk_hw hw;
18 unsigned long rate_min;
19 unsigned long rate_max;
20};
21
22#define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw)
23
24static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw,
25 unsigned long parent_rate)
26{
27 struct vexpress_osc *osc = to_vexpress_osc(hw);
28 u32 rate;
29
30 regmap_read(osc->reg, 0, &rate);
31
32 return rate;
33}
34
35static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate,
36 unsigned long *parent_rate)
37{
38 struct vexpress_osc *osc = to_vexpress_osc(hw);
39
40 if (osc->rate_min && rate < osc->rate_min)
41 rate = osc->rate_min;
42
43 if (osc->rate_max && rate > osc->rate_max)
44 rate = osc->rate_max;
45
46 return rate;
47}
48
49static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate,
50 unsigned long parent_rate)
51{
52 struct vexpress_osc *osc = to_vexpress_osc(hw);
53
54 return regmap_write(osc->reg, 0, rate);
55}
56
57static const struct clk_ops vexpress_osc_ops = {
58 .recalc_rate = vexpress_osc_recalc_rate,
59 .round_rate = vexpress_osc_round_rate,
60 .set_rate = vexpress_osc_set_rate,
61};
62
63
64static int vexpress_osc_probe(struct platform_device *pdev)
65{
66 struct clk_init_data init;
67 struct vexpress_osc *osc;
68 struct clk *clk;
69 u32 range[2];
70
71 osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL);
72 if (!osc)
73 return -ENOMEM;
74
75 osc->reg = devm_regmap_init_vexpress_config(&pdev->dev);
76 if (IS_ERR(osc->reg))
77 return PTR_ERR(osc->reg);
78
79 if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range,
80 ARRAY_SIZE(range)) == 0) {
81 osc->rate_min = range[0];
82 osc->rate_max = range[1];
83 }
84
85 if (of_property_read_string(pdev->dev.of_node, "clock-output-names",
86 &init.name) != 0)
87 init.name = dev_name(&pdev->dev);
88
89 init.ops = &vexpress_osc_ops;
90 init.flags = 0;
91 init.num_parents = 0;
92
93 osc->hw.init = &init;
94
95 clk = clk_register(NULL, &osc->hw);
96 if (IS_ERR(clk))
97 return PTR_ERR(clk);
98
99 of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, clk);
100 clk_hw_set_rate_range(&osc->hw, osc->rate_min, osc->rate_max);
101
102 dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name);
103
104 return 0;
105}
106
107static const struct of_device_id vexpress_osc_of_match[] = {
108 { .compatible = "arm,vexpress-osc", },
109 {}
110};
111
112static struct platform_driver vexpress_osc_driver = {
113 .driver = {
114 .name = "vexpress-osc",
115 .of_match_table = vexpress_osc_of_match,
116 },
117 .probe = vexpress_osc_probe,
118};
119
120static int __init vexpress_osc_init(void)
121{
122 return platform_driver_register(&vexpress_osc_driver);
123}
124core_initcall(vexpress_osc_init);
125
