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ed27ff1d PM |
1 | /* |
2 | * This program is free software; you can redistribute it and/or modify | |
3 | * it under the terms of the GNU General Public License version 2 as | |
4 | * published by the Free Software Foundation. | |
5 | * | |
6 | * This program is distributed in the hope that it will be useful, | |
7 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
8 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
9 | * GNU General Public License for more details. | |
10 | * | |
11 | * Copyright (C) 2012 ARM Limited | |
12 | */ | |
13 | ||
ed27ff1d PM |
14 | #include <linux/clkdev.h> |
15 | #include <linux/clk-provider.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/of.h> | |
18 | #include <linux/platform_device.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/vexpress.h> | |
21 | ||
22 | struct vexpress_osc { | |
3b9334ac | 23 | struct regmap *reg; |
ed27ff1d PM |
24 | struct clk_hw hw; |
25 | unsigned long rate_min; | |
26 | unsigned long rate_max; | |
27 | }; | |
28 | ||
29 | #define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw) | |
30 | ||
31 | static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw, | |
32 | unsigned long parent_rate) | |
33 | { | |
34 | struct vexpress_osc *osc = to_vexpress_osc(hw); | |
35 | u32 rate; | |
36 | ||
3b9334ac | 37 | regmap_read(osc->reg, 0, &rate); |
ed27ff1d PM |
38 | |
39 | return rate; | |
40 | } | |
41 | ||
42 | static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate, | |
43 | unsigned long *parent_rate) | |
44 | { | |
45 | struct vexpress_osc *osc = to_vexpress_osc(hw); | |
46 | ||
47 | if (WARN_ON(osc->rate_min && rate < osc->rate_min)) | |
48 | rate = osc->rate_min; | |
49 | ||
50 | if (WARN_ON(osc->rate_max && rate > osc->rate_max)) | |
51 | rate = osc->rate_max; | |
52 | ||
53 | return rate; | |
54 | } | |
55 | ||
56 | static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate, | |
57 | unsigned long parent_rate) | |
58 | { | |
59 | struct vexpress_osc *osc = to_vexpress_osc(hw); | |
60 | ||
3b9334ac | 61 | return regmap_write(osc->reg, 0, rate); |
ed27ff1d PM |
62 | } |
63 | ||
64 | static struct clk_ops vexpress_osc_ops = { | |
65 | .recalc_rate = vexpress_osc_recalc_rate, | |
66 | .round_rate = vexpress_osc_round_rate, | |
67 | .set_rate = vexpress_osc_set_rate, | |
68 | }; | |
69 | ||
70 | ||
3b9334ac | 71 | static int vexpress_osc_probe(struct platform_device *pdev) |
ed27ff1d | 72 | { |
3b9334ac | 73 | struct clk_lookup *cl = pdev->dev.platform_data; /* Non-DT lookup */ |
ed27ff1d PM |
74 | struct clk_init_data init; |
75 | struct vexpress_osc *osc; | |
76 | struct clk *clk; | |
77 | u32 range[2]; | |
78 | ||
3b9334ac | 79 | osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL); |
ed27ff1d | 80 | if (!osc) |
3b9334ac | 81 | return -ENOMEM; |
ed27ff1d | 82 | |
3b9334ac PM |
83 | osc->reg = devm_regmap_init_vexpress_config(&pdev->dev); |
84 | if (IS_ERR(osc->reg)) | |
85 | return PTR_ERR(osc->reg); | |
ed27ff1d | 86 | |
3b9334ac | 87 | if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range, |
ed27ff1d PM |
88 | ARRAY_SIZE(range)) == 0) { |
89 | osc->rate_min = range[0]; | |
90 | osc->rate_max = range[1]; | |
91 | } | |
92 | ||
3b9334ac PM |
93 | if (of_property_read_string(pdev->dev.of_node, "clock-output-names", |
94 | &init.name) != 0) | |
95 | init.name = dev_name(&pdev->dev); | |
ed27ff1d PM |
96 | |
97 | init.ops = &vexpress_osc_ops; | |
98 | init.flags = CLK_IS_ROOT; | |
99 | init.num_parents = 0; | |
100 | ||
101 | osc->hw.init = &init; | |
102 | ||
103 | clk = clk_register(NULL, &osc->hw); | |
3b9334ac PM |
104 | if (IS_ERR(clk)) |
105 | return PTR_ERR(clk); | |
106 | ||
107 | of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, clk); | |
108 | ||
109 | /* Only happens for non-DT cases */ | |
110 | if (cl) { | |
111 | cl->clk = clk; | |
112 | clkdev_add(cl); | |
ed27ff1d PM |
113 | } |
114 | ||
3b9334ac PM |
115 | dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name); |
116 | ||
117 | return 0; | |
118 | } | |
ed27ff1d | 119 | |
3b9334ac PM |
120 | static struct of_device_id vexpress_osc_of_match[] = { |
121 | { .compatible = "arm,vexpress-osc", }, | |
122 | {} | |
123 | }; | |
ed27ff1d | 124 | |
3b9334ac PM |
125 | static struct platform_driver vexpress_osc_driver = { |
126 | .driver = { | |
127 | .name = "vexpress-osc", | |
128 | .of_match_table = vexpress_osc_of_match, | |
129 | }, | |
130 | .probe = vexpress_osc_probe, | |
131 | }; | |
ed27ff1d | 132 | |
3b9334ac PM |
133 | static int __init vexpress_osc_init(void) |
134 | { | |
135 | return platform_driver_register(&vexpress_osc_driver); | |
ed27ff1d | 136 | } |
3b9334ac | 137 | core_initcall(vexpress_osc_init); |