clk: Tag basic clk types with SPDX
[sfrench/cifs-2.6.git] / drivers / clk / clk-fixed-factor.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
4  */
5 #include <linux/module.h>
6 #include <linux/clk-provider.h>
7 #include <linux/slab.h>
8 #include <linux/err.h>
9 #include <linux/of.h>
10 #include <linux/platform_device.h>
11
12 /*
13  * DOC: basic fixed multiplier and divider clock that cannot gate
14  *
15  * Traits of this clock:
16  * prepare - clk_prepare only ensures that parents are prepared
17  * enable - clk_enable only ensures that parents are enabled
18  * rate - rate is fixed.  clk->rate = parent->rate / div * mult
19  * parent - fixed parent.  No clk_set_parent support
20  */
21
22 static unsigned long clk_factor_recalc_rate(struct clk_hw *hw,
23                 unsigned long parent_rate)
24 {
25         struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
26         unsigned long long int rate;
27
28         rate = (unsigned long long int)parent_rate * fix->mult;
29         do_div(rate, fix->div);
30         return (unsigned long)rate;
31 }
32
33 static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate,
34                                 unsigned long *prate)
35 {
36         struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
37
38         if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
39                 unsigned long best_parent;
40
41                 best_parent = (rate / fix->mult) * fix->div;
42                 *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
43         }
44
45         return (*prate / fix->div) * fix->mult;
46 }
47
48 static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
49                                 unsigned long parent_rate)
50 {
51         /*
52          * We must report success but we can do so unconditionally because
53          * clk_factor_round_rate returns values that ensure this call is a
54          * nop.
55          */
56
57         return 0;
58 }
59
60 const struct clk_ops clk_fixed_factor_ops = {
61         .round_rate = clk_factor_round_rate,
62         .set_rate = clk_factor_set_rate,
63         .recalc_rate = clk_factor_recalc_rate,
64 };
65 EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
66
67 struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
68                 const char *name, const char *parent_name, unsigned long flags,
69                 unsigned int mult, unsigned int div)
70 {
71         struct clk_fixed_factor *fix;
72         struct clk_init_data init;
73         struct clk_hw *hw;
74         int ret;
75
76         fix = kmalloc(sizeof(*fix), GFP_KERNEL);
77         if (!fix)
78                 return ERR_PTR(-ENOMEM);
79
80         /* struct clk_fixed_factor assignments */
81         fix->mult = mult;
82         fix->div = div;
83         fix->hw.init = &init;
84
85         init.name = name;
86         init.ops = &clk_fixed_factor_ops;
87         init.flags = flags | CLK_IS_BASIC;
88         init.parent_names = &parent_name;
89         init.num_parents = 1;
90
91         hw = &fix->hw;
92         ret = clk_hw_register(dev, hw);
93         if (ret) {
94                 kfree(fix);
95                 hw = ERR_PTR(ret);
96         }
97
98         return hw;
99 }
100 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
101
102 struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
103                 const char *parent_name, unsigned long flags,
104                 unsigned int mult, unsigned int div)
105 {
106         struct clk_hw *hw;
107
108         hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult,
109                                           div);
110         if (IS_ERR(hw))
111                 return ERR_CAST(hw);
112         return hw->clk;
113 }
114 EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
115
116 void clk_unregister_fixed_factor(struct clk *clk)
117 {
118         struct clk_hw *hw;
119
120         hw = __clk_get_hw(clk);
121         if (!hw)
122                 return;
123
124         clk_unregister(clk);
125         kfree(to_clk_fixed_factor(hw));
126 }
127 EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
128
129 void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
130 {
131         struct clk_fixed_factor *fix;
132
133         fix = to_clk_fixed_factor(hw);
134
135         clk_hw_unregister(hw);
136         kfree(fix);
137 }
138 EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
139
140 #ifdef CONFIG_OF
141 static const struct of_device_id set_rate_parent_matches[] = {
142         { .compatible = "allwinner,sun4i-a10-pll3-2x-clk" },
143         { /* Sentinel */ },
144 };
145
146 static struct clk *_of_fixed_factor_clk_setup(struct device_node *node)
147 {
148         struct clk *clk;
149         const char *clk_name = node->name;
150         const char *parent_name;
151         unsigned long flags = 0;
152         u32 div, mult;
153         int ret;
154
155         if (of_property_read_u32(node, "clock-div", &div)) {
156                 pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n",
157                         __func__, node);
158                 return ERR_PTR(-EIO);
159         }
160
161         if (of_property_read_u32(node, "clock-mult", &mult)) {
162                 pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n",
163                         __func__, node);
164                 return ERR_PTR(-EIO);
165         }
166
167         of_property_read_string(node, "clock-output-names", &clk_name);
168         parent_name = of_clk_get_parent_name(node, 0);
169
170         if (of_match_node(set_rate_parent_matches, node))
171                 flags |= CLK_SET_RATE_PARENT;
172
173         clk = clk_register_fixed_factor(NULL, clk_name, parent_name, flags,
174                                         mult, div);
175         if (IS_ERR(clk)) {
176                 /*
177                  * If parent clock is not registered, registration would fail.
178                  * Clear OF_POPULATED flag so that clock registration can be
179                  * attempted again from probe function.
180                  */
181                 of_node_clear_flag(node, OF_POPULATED);
182                 return clk;
183         }
184
185         ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
186         if (ret) {
187                 clk_unregister(clk);
188                 return ERR_PTR(ret);
189         }
190
191         return clk;
192 }
193
194 /**
195  * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
196  */
197 void __init of_fixed_factor_clk_setup(struct device_node *node)
198 {
199         _of_fixed_factor_clk_setup(node);
200 }
201 CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
202                 of_fixed_factor_clk_setup);
203
204 static int of_fixed_factor_clk_remove(struct platform_device *pdev)
205 {
206         struct clk *clk = platform_get_drvdata(pdev);
207
208         clk_unregister_fixed_factor(clk);
209
210         return 0;
211 }
212
213 static int of_fixed_factor_clk_probe(struct platform_device *pdev)
214 {
215         struct clk *clk;
216
217         /*
218          * This function is not executed when of_fixed_factor_clk_setup
219          * succeeded.
220          */
221         clk = _of_fixed_factor_clk_setup(pdev->dev.of_node);
222         if (IS_ERR(clk))
223                 return PTR_ERR(clk);
224
225         platform_set_drvdata(pdev, clk);
226
227         return 0;
228 }
229
230 static const struct of_device_id of_fixed_factor_clk_ids[] = {
231         { .compatible = "fixed-factor-clock" },
232         { }
233 };
234 MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
235
236 static struct platform_driver of_fixed_factor_clk_driver = {
237         .driver = {
238                 .name = "of_fixed_factor_clk",
239                 .of_match_table = of_fixed_factor_clk_ids,
240         },
241         .probe = of_fixed_factor_clk_probe,
242         .remove = of_fixed_factor_clk_remove,
243 };
244 builtin_platform_driver(of_fixed_factor_clk_driver);
245 #endif