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f0948f59 SH |
1 | /* |
2 | * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * Standard functionality for the common clock API. | |
9 | */ | |
10 | #include <linux/module.h> | |
11 | #include <linux/clk-provider.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/err.h> | |
79b16641 | 14 | #include <linux/of.h> |
971451b3 | 15 | #include <linux/platform_device.h> |
f0948f59 SH |
16 | |
17 | /* | |
18 | * DOC: basic fixed multiplier and divider clock that cannot gate | |
19 | * | |
20 | * Traits of this clock: | |
21 | * prepare - clk_prepare only ensures that parents are prepared | |
22 | * enable - clk_enable only ensures that parents are enabled | |
23 | * rate - rate is fixed. clk->rate = parent->rate / div * mult | |
24 | * parent - fixed parent. No clk_set_parent support | |
25 | */ | |
26 | ||
f0948f59 SH |
27 | static unsigned long clk_factor_recalc_rate(struct clk_hw *hw, |
28 | unsigned long parent_rate) | |
29 | { | |
30 | struct clk_fixed_factor *fix = to_clk_fixed_factor(hw); | |
bab53301 | 31 | unsigned long long int rate; |
f0948f59 | 32 | |
bab53301 HZ |
33 | rate = (unsigned long long int)parent_rate * fix->mult; |
34 | do_div(rate, fix->div); | |
35 | return (unsigned long)rate; | |
f0948f59 SH |
36 | } |
37 | ||
38 | static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate, | |
39 | unsigned long *prate) | |
40 | { | |
41 | struct clk_fixed_factor *fix = to_clk_fixed_factor(hw); | |
42 | ||
98d8a60e | 43 | if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) { |
f0948f59 SH |
44 | unsigned long best_parent; |
45 | ||
46 | best_parent = (rate / fix->mult) * fix->div; | |
2f508a95 | 47 | *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent); |
f0948f59 SH |
48 | } |
49 | ||
50 | return (*prate / fix->div) * fix->mult; | |
51 | } | |
52 | ||
53 | static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate, | |
54 | unsigned long parent_rate) | |
55 | { | |
3037e9ea DT |
56 | /* |
57 | * We must report success but we can do so unconditionally because | |
58 | * clk_factor_round_rate returns values that ensure this call is a | |
59 | * nop. | |
60 | */ | |
61 | ||
f0948f59 SH |
62 | return 0; |
63 | } | |
64 | ||
3037e9ea | 65 | const struct clk_ops clk_fixed_factor_ops = { |
f0948f59 SH |
66 | .round_rate = clk_factor_round_rate, |
67 | .set_rate = clk_factor_set_rate, | |
68 | .recalc_rate = clk_factor_recalc_rate, | |
69 | }; | |
70 | EXPORT_SYMBOL_GPL(clk_fixed_factor_ops); | |
71 | ||
0759ac8a SB |
72 | struct clk_hw *clk_hw_register_fixed_factor(struct device *dev, |
73 | const char *name, const char *parent_name, unsigned long flags, | |
f0948f59 SH |
74 | unsigned int mult, unsigned int div) |
75 | { | |
76 | struct clk_fixed_factor *fix; | |
77 | struct clk_init_data init; | |
0759ac8a SB |
78 | struct clk_hw *hw; |
79 | int ret; | |
f0948f59 SH |
80 | |
81 | fix = kmalloc(sizeof(*fix), GFP_KERNEL); | |
d122db7e | 82 | if (!fix) |
f0948f59 | 83 | return ERR_PTR(-ENOMEM); |
f0948f59 SH |
84 | |
85 | /* struct clk_fixed_factor assignments */ | |
86 | fix->mult = mult; | |
87 | fix->div = div; | |
88 | fix->hw.init = &init; | |
89 | ||
90 | init.name = name; | |
91 | init.ops = &clk_fixed_factor_ops; | |
f7d8caad | 92 | init.flags = flags | CLK_IS_BASIC; |
f0948f59 SH |
93 | init.parent_names = &parent_name; |
94 | init.num_parents = 1; | |
95 | ||
0759ac8a SB |
96 | hw = &fix->hw; |
97 | ret = clk_hw_register(dev, hw); | |
98 | if (ret) { | |
f0948f59 | 99 | kfree(fix); |
0759ac8a SB |
100 | hw = ERR_PTR(ret); |
101 | } | |
f0948f59 | 102 | |
0759ac8a SB |
103 | return hw; |
104 | } | |
105 | EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor); | |
106 | ||
107 | struct clk *clk_register_fixed_factor(struct device *dev, const char *name, | |
108 | const char *parent_name, unsigned long flags, | |
109 | unsigned int mult, unsigned int div) | |
110 | { | |
111 | struct clk_hw *hw; | |
112 | ||
113 | hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult, | |
114 | div); | |
115 | if (IS_ERR(hw)) | |
116 | return ERR_CAST(hw); | |
117 | return hw->clk; | |
f0948f59 | 118 | } |
5cfe10bb | 119 | EXPORT_SYMBOL_GPL(clk_register_fixed_factor); |
cbf9591f MY |
120 | |
121 | void clk_unregister_fixed_factor(struct clk *clk) | |
122 | { | |
123 | struct clk_hw *hw; | |
124 | ||
125 | hw = __clk_get_hw(clk); | |
126 | if (!hw) | |
127 | return; | |
128 | ||
129 | clk_unregister(clk); | |
130 | kfree(to_clk_fixed_factor(hw)); | |
131 | } | |
132 | EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor); | |
0759ac8a SB |
133 | |
134 | void clk_hw_unregister_fixed_factor(struct clk_hw *hw) | |
135 | { | |
136 | struct clk_fixed_factor *fix; | |
137 | ||
138 | fix = to_clk_fixed_factor(hw); | |
139 | ||
140 | clk_hw_unregister(hw); | |
141 | kfree(fix); | |
142 | } | |
143 | EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor); | |
5cfe10bb | 144 | |
79b16641 | 145 | #ifdef CONFIG_OF |
e6cbf998 MR |
146 | static const struct of_device_id set_rate_parent_matches[] = { |
147 | { .compatible = "allwinner,sun4i-a10-pll3-2x-clk" }, | |
148 | { /* Sentinel */ }, | |
149 | }; | |
150 | ||
971451b3 | 151 | static struct clk *_of_fixed_factor_clk_setup(struct device_node *node) |
79b16641 GC |
152 | { |
153 | struct clk *clk; | |
154 | const char *clk_name = node->name; | |
155 | const char *parent_name; | |
e6cbf998 | 156 | unsigned long flags = 0; |
79b16641 | 157 | u32 div, mult; |
971451b3 | 158 | int ret; |
79b16641 GC |
159 | |
160 | if (of_property_read_u32(node, "clock-div", &div)) { | |
161 | pr_err("%s Fixed factor clock <%s> must have a clock-div property\n", | |
162 | __func__, node->name); | |
971451b3 | 163 | return ERR_PTR(-EIO); |
79b16641 GC |
164 | } |
165 | ||
166 | if (of_property_read_u32(node, "clock-mult", &mult)) { | |
fe2fd5cc | 167 | pr_err("%s Fixed factor clock <%s> must have a clock-mult property\n", |
79b16641 | 168 | __func__, node->name); |
971451b3 | 169 | return ERR_PTR(-EIO); |
79b16641 GC |
170 | } |
171 | ||
172 | of_property_read_string(node, "clock-output-names", &clk_name); | |
173 | parent_name = of_clk_get_parent_name(node, 0); | |
174 | ||
e6cbf998 MR |
175 | if (of_match_node(set_rate_parent_matches, node)) |
176 | flags |= CLK_SET_RATE_PARENT; | |
177 | ||
178 | clk = clk_register_fixed_factor(NULL, clk_name, parent_name, flags, | |
79b16641 | 179 | mult, div); |
971451b3 RRD |
180 | if (IS_ERR(clk)) |
181 | return clk; | |
182 | ||
183 | ret = of_clk_add_provider(node, of_clk_src_simple_get, clk); | |
184 | if (ret) { | |
185 | clk_unregister(clk); | |
186 | return ERR_PTR(ret); | |
187 | } | |
188 | ||
189 | return clk; | |
190 | } | |
191 | ||
192 | /** | |
193 | * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock | |
194 | */ | |
195 | void __init of_fixed_factor_clk_setup(struct device_node *node) | |
196 | { | |
197 | _of_fixed_factor_clk_setup(node); | |
79b16641 | 198 | } |
79b16641 GC |
199 | CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock", |
200 | of_fixed_factor_clk_setup); | |
971451b3 RRD |
201 | |
202 | static int of_fixed_factor_clk_remove(struct platform_device *pdev) | |
203 | { | |
204 | struct clk *clk = platform_get_drvdata(pdev); | |
205 | ||
206 | clk_unregister_fixed_factor(clk); | |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
211 | static int of_fixed_factor_clk_probe(struct platform_device *pdev) | |
212 | { | |
213 | struct clk *clk; | |
214 | ||
215 | /* | |
216 | * This function is not executed when of_fixed_factor_clk_setup | |
217 | * succeeded. | |
218 | */ | |
219 | clk = _of_fixed_factor_clk_setup(pdev->dev.of_node); | |
220 | if (IS_ERR(clk)) | |
221 | return PTR_ERR(clk); | |
222 | ||
223 | platform_set_drvdata(pdev, clk); | |
224 | ||
225 | return 0; | |
226 | } | |
227 | ||
228 | static const struct of_device_id of_fixed_factor_clk_ids[] = { | |
229 | { .compatible = "fixed-factor-clock" }, | |
230 | { } | |
231 | }; | |
232 | MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids); | |
233 | ||
234 | static struct platform_driver of_fixed_factor_clk_driver = { | |
235 | .driver = { | |
236 | .name = "of_fixed_factor_clk", | |
237 | .of_match_table = of_fixed_factor_clk_ids, | |
238 | }, | |
239 | .probe = of_fixed_factor_clk_probe, | |
240 | .remove = of_fixed_factor_clk_remove, | |
241 | }; | |
242 | builtin_platform_driver(of_fixed_factor_clk_driver); | |
79b16641 | 243 | #endif |