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/of.h>
11 #include <linux/platform_device.h>
12 #include <linux/slab.h>
13 #include <linux/vexpress.h>
14
15 struct 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
vexpress_osc_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)24 static 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
vexpress_osc_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)35 static 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
vexpress_osc_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)49 static 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
57 static 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
vexpress_osc_probe(struct platform_device * pdev)64 static 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
107 static const struct of_device_id vexpress_osc_of_match[] = {
108 { .compatible = "arm,vexpress-osc", },
109 {}
110 };
111
112 static 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
vexpress_osc_init(void)120 static int __init vexpress_osc_init(void)
121 {
122 return platform_driver_register(&vexpress_osc_driver);
123 }
124 core_initcall(vexpress_osc_init);
125
