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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>
14
15/*
16 * DOC: basic fixed multiplier and divider clock that cannot gate
17 *
18 * Traits of this clock:
19 * prepare - clk_prepare only ensures that parents are prepared
20 * enable - clk_enable only ensures that parents are enabled
21 * rate - rate is fixed. clk->rate = parent->rate / div * mult
22 * parent - fixed parent. No clk_set_parent support
23 */
24
25#define to_clk_fixed_factor(_hw) container_of(_hw, struct clk_fixed_factor, hw)
26
27static 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);
31
32 return parent_rate * fix->mult / fix->div;
33}
34
35static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate,
36 unsigned long *prate)
37{
38 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
39
40 if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) {
41 unsigned long best_parent;
42
43 best_parent = (rate / fix->mult) * fix->div;
44 *prate = __clk_round_rate(__clk_get_parent(hw->clk),
45 best_parent);
46 }
47
48 return (*prate / fix->div) * fix->mult;
49}
50
51static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
52 unsigned long parent_rate)
53{
54 return 0;
55}
56
57struct clk_ops clk_fixed_factor_ops = {
58 .round_rate = clk_factor_round_rate,
59 .set_rate = clk_factor_set_rate,
60 .recalc_rate = clk_factor_recalc_rate,
61};
62EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
63
64struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
65 const char *parent_name, unsigned long flags,
66 unsigned int mult, unsigned int div)
67{
68 struct clk_fixed_factor *fix;
69 struct clk_init_data init;
70 struct clk *clk;
71
72 fix = kmalloc(sizeof(*fix), GFP_KERNEL);
73 if (!fix) {
74 pr_err("%s: could not allocate fixed factor clk\n", __func__);
75 return ERR_PTR(-ENOMEM);
76 }
77
78 /* struct clk_fixed_factor assignments */
79 fix->mult = mult;
80 fix->div = div;
81 fix->hw.init = &init;
82
83 init.name = name;
84 init.ops = &clk_fixed_factor_ops;
85 init.flags = flags;
86 init.parent_names = &parent_name;
87 init.num_parents = 1;
88
89 clk = clk_register(dev, &fix->hw);
90
91 if (IS_ERR(clk))
92 kfree(fix);
93
94 return clk;
95}
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
22static 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
33static 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
48static 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
60const 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};
65EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
66
67static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res)
68{
69 struct clk_fixed_factor *fix = res;
70
71 /*
72 * We can not use clk_hw_unregister_fixed_factor, since it will kfree()
73 * the hw, resulting in double free. Just unregister the hw and let
74 * devres code kfree() it.
75 */
76 clk_hw_unregister(&fix->hw);
77}
78
79static struct clk_hw *
80__clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
81 const char *name, const char *parent_name, int index,
82 unsigned long flags, unsigned int mult, unsigned int div,
83 bool devm)
84{
85 struct clk_fixed_factor *fix;
86 struct clk_init_data init = { };
87 struct clk_parent_data pdata = { .index = index };
88 struct clk_hw *hw;
89 int ret;
90
91 /* You can't use devm without a dev */
92 if (devm && !dev)
93 return ERR_PTR(-EINVAL);
94
95 if (devm)
96 fix = devres_alloc(devm_clk_hw_register_fixed_factor_release,
97 sizeof(*fix), GFP_KERNEL);
98 else
99 fix = kmalloc(sizeof(*fix), GFP_KERNEL);
100 if (!fix)
101 return ERR_PTR(-ENOMEM);
102
103 /* struct clk_fixed_factor assignments */
104 fix->mult = mult;
105 fix->div = div;
106 fix->hw.init = &init;
107
108 init.name = name;
109 init.ops = &clk_fixed_factor_ops;
110 init.flags = flags;
111 if (parent_name)
112 init.parent_names = &parent_name;
113 else
114 init.parent_data = &pdata;
115 init.num_parents = 1;
116
117 hw = &fix->hw;
118 if (dev)
119 ret = clk_hw_register(dev, hw);
120 else
121 ret = of_clk_hw_register(np, hw);
122 if (ret) {
123 if (devm)
124 devres_free(fix);
125 else
126 kfree(fix);
127 hw = ERR_PTR(ret);
128 } else if (devm)
129 devres_add(dev, fix);
130
131 return hw;
132}
133
134struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
135 const char *name, const char *parent_name, unsigned long flags,
136 unsigned int mult, unsigned int div)
137{
138 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, -1,
139 flags, mult, div, false);
140}
141EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
142
143struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
144 const char *parent_name, unsigned long flags,
145 unsigned int mult, unsigned int div)
146{
147 struct clk_hw *hw;
148
149 hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult,
150 div);
151 if (IS_ERR(hw))
152 return ERR_CAST(hw);
153 return hw->clk;
154}
155EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
156
157void clk_unregister_fixed_factor(struct clk *clk)
158{
159 struct clk_hw *hw;
160
161 hw = __clk_get_hw(clk);
162 if (!hw)
163 return;
164
165 clk_unregister(clk);
166 kfree(to_clk_fixed_factor(hw));
167}
168EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
169
170void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
171{
172 struct clk_fixed_factor *fix;
173
174 fix = to_clk_fixed_factor(hw);
175
176 clk_hw_unregister(hw);
177 kfree(fix);
178}
179EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
180
181struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
182 const char *name, const char *parent_name, unsigned long flags,
183 unsigned int mult, unsigned int div)
184{
185 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, -1,
186 flags, mult, div, true);
187}
188EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);
189
190#ifdef CONFIG_OF
191static const struct of_device_id set_rate_parent_matches[] = {
192 { .compatible = "allwinner,sun4i-a10-pll3-2x-clk" },
193 { /* Sentinel */ },
194};
195
196static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
197{
198 struct clk_hw *hw;
199 const char *clk_name = node->name;
200 unsigned long flags = 0;
201 u32 div, mult;
202 int ret;
203
204 if (of_property_read_u32(node, "clock-div", &div)) {
205 pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n",
206 __func__, node);
207 return ERR_PTR(-EIO);
208 }
209
210 if (of_property_read_u32(node, "clock-mult", &mult)) {
211 pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n",
212 __func__, node);
213 return ERR_PTR(-EIO);
214 }
215
216 of_property_read_string(node, "clock-output-names", &clk_name);
217
218 if (of_match_node(set_rate_parent_matches, node))
219 flags |= CLK_SET_RATE_PARENT;
220
221 hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, 0,
222 flags, mult, div, false);
223 if (IS_ERR(hw)) {
224 /*
225 * Clear OF_POPULATED flag so that clock registration can be
226 * attempted again from probe function.
227 */
228 of_node_clear_flag(node, OF_POPULATED);
229 return ERR_CAST(hw);
230 }
231
232 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
233 if (ret) {
234 clk_hw_unregister_fixed_factor(hw);
235 return ERR_PTR(ret);
236 }
237
238 return hw;
239}
240
241/**
242 * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
243 * @node: device node for the clock
244 */
245void __init of_fixed_factor_clk_setup(struct device_node *node)
246{
247 _of_fixed_factor_clk_setup(node);
248}
249CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
250 of_fixed_factor_clk_setup);
251
252static int of_fixed_factor_clk_remove(struct platform_device *pdev)
253{
254 struct clk_hw *clk = platform_get_drvdata(pdev);
255
256 of_clk_del_provider(pdev->dev.of_node);
257 clk_hw_unregister_fixed_factor(clk);
258
259 return 0;
260}
261
262static int of_fixed_factor_clk_probe(struct platform_device *pdev)
263{
264 struct clk_hw *clk;
265
266 /*
267 * This function is not executed when of_fixed_factor_clk_setup
268 * succeeded.
269 */
270 clk = _of_fixed_factor_clk_setup(pdev->dev.of_node);
271 if (IS_ERR(clk))
272 return PTR_ERR(clk);
273
274 platform_set_drvdata(pdev, clk);
275
276 return 0;
277}
278
279static const struct of_device_id of_fixed_factor_clk_ids[] = {
280 { .compatible = "fixed-factor-clock" },
281 { }
282};
283MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
284
285static struct platform_driver of_fixed_factor_clk_driver = {
286 .driver = {
287 .name = "of_fixed_factor_clk",
288 .of_match_table = of_fixed_factor_clk_ids,
289 },
290 .probe = of_fixed_factor_clk_probe,
291 .remove = of_fixed_factor_clk_remove,
292};
293builtin_platform_driver(of_fixed_factor_clk_driver);
294#endif