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Sascha Hauerf0948f52012-05-03 15:36:14 +05301/*
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>
Gregory CLEMENT79b16642013-04-12 13:57:44 +020014#include <linux/of.h>
Ricardo Ribalda Delgado971451b2016-07-05 18:23:33 +020015#include <linux/platform_device.h>
Sascha Hauerf0948f52012-05-03 15:36:14 +053016
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
Sascha Hauerf0948f52012-05-03 15:36:14 +053027static 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);
Haojian Zhuangbab53302012-12-03 16:14:37 +080031 unsigned long long int rate;
Sascha Hauerf0948f52012-05-03 15:36:14 +053032
Haojian Zhuangbab53302012-12-03 16:14:37 +080033 rate = (unsigned long long int)parent_rate * fix->mult;
34 do_div(rate, fix->div);
35 return (unsigned long)rate;
Sascha Hauerf0948f52012-05-03 15:36:14 +053036}
37
38static 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
Stephen Boyd98d8a602015-06-29 16:56:30 -070043 if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
Sascha Hauerf0948f52012-05-03 15:36:14 +053044 unsigned long best_parent;
45
46 best_parent = (rate / fix->mult) * fix->div;
Stephen Boyd2f508a92015-07-30 17:20:57 -070047 *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
Sascha Hauerf0948f52012-05-03 15:36:14 +053048 }
49
50 return (*prate / fix->div) * fix->mult;
51}
52
53static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
54 unsigned long parent_rate)
55{
Daniel Thompson3037e9e2015-06-10 21:04:54 +010056 /*
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
Sascha Hauerf0948f52012-05-03 15:36:14 +053062 return 0;
63}
64
Daniel Thompson3037e9e2015-06-10 21:04:54 +010065const struct clk_ops clk_fixed_factor_ops = {
Sascha Hauerf0948f52012-05-03 15:36:14 +053066 .round_rate = clk_factor_round_rate,
67 .set_rate = clk_factor_set_rate,
68 .recalc_rate = clk_factor_recalc_rate,
69};
70EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
71
Stephen Boyd0759ac82016-02-07 00:11:06 -080072struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
73 const char *name, const char *parent_name, unsigned long flags,
Sascha Hauerf0948f52012-05-03 15:36:14 +053074 unsigned int mult, unsigned int div)
75{
76 struct clk_fixed_factor *fix;
77 struct clk_init_data init;
Stephen Boyd0759ac82016-02-07 00:11:06 -080078 struct clk_hw *hw;
79 int ret;
Sascha Hauerf0948f52012-05-03 15:36:14 +053080
81 fix = kmalloc(sizeof(*fix), GFP_KERNEL);
Stephen Boydd122db72015-05-14 16:47:10 -070082 if (!fix)
Sascha Hauerf0948f52012-05-03 15:36:14 +053083 return ERR_PTR(-ENOMEM);
Sascha Hauerf0948f52012-05-03 15:36:14 +053084
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;
Rajendra Nayakf7d8caa2012-06-01 14:02:47 +053092 init.flags = flags | CLK_IS_BASIC;
Sascha Hauerf0948f52012-05-03 15:36:14 +053093 init.parent_names = &parent_name;
94 init.num_parents = 1;
95
Stephen Boyd0759ac82016-02-07 00:11:06 -080096 hw = &fix->hw;
97 ret = clk_hw_register(dev, hw);
98 if (ret) {
Sascha Hauerf0948f52012-05-03 15:36:14 +053099 kfree(fix);
Stephen Boyd0759ac82016-02-07 00:11:06 -0800100 hw = ERR_PTR(ret);
101 }
Sascha Hauerf0948f52012-05-03 15:36:14 +0530102
Stephen Boyd0759ac82016-02-07 00:11:06 -0800103 return hw;
104}
105EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
106
107struct 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;
Sascha Hauerf0948f52012-05-03 15:36:14 +0530118}
Mike Turquette5cfe10b2013-08-15 19:06:29 -0700119EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
120
Masahiro Yamadacbf95912016-01-06 13:25:09 +0900121void 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}
132EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
133
Stephen Boyd0759ac82016-02-07 00:11:06 -0800134void 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}
143EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
144
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200145#ifdef CONFIG_OF
Maxime Riparde6cbf992016-06-22 11:15:54 +0200146static const struct of_device_id set_rate_parent_matches[] = {
147 { .compatible = "allwinner,sun4i-a10-pll3-2x-clk" },
148 { /* Sentinel */ },
149};
150
Ricardo Ribalda Delgado971451b2016-07-05 18:23:33 +0200151static struct clk *_of_fixed_factor_clk_setup(struct device_node *node)
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200152{
153 struct clk *clk;
154 const char *clk_name = node->name;
155 const char *parent_name;
Maxime Riparde6cbf992016-06-22 11:15:54 +0200156 unsigned long flags = 0;
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200157 u32 div, mult;
Ricardo Ribalda Delgado971451b2016-07-05 18:23:33 +0200158 int ret;
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200159
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);
Ricardo Ribalda Delgado971451b2016-07-05 18:23:33 +0200163 return ERR_PTR(-EIO);
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200164 }
165
166 if (of_property_read_u32(node, "clock-mult", &mult)) {
Ezequiel Garciafe2fd5c2013-09-25 16:08:46 -0300167 pr_err("%s Fixed factor clock <%s> must have a clock-mult property\n",
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200168 __func__, node->name);
Ricardo Ribalda Delgado971451b2016-07-05 18:23:33 +0200169 return ERR_PTR(-EIO);
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200170 }
171
172 of_property_read_string(node, "clock-output-names", &clk_name);
173 parent_name = of_clk_get_parent_name(node, 0);
174
Maxime Riparde6cbf992016-06-22 11:15:54 +0200175 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,
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200179 mult, div);
Ricardo Ribalda Delgado971451b2016-07-05 18:23:33 +0200180 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 */
195void __init of_fixed_factor_clk_setup(struct device_node *node)
196{
197 _of_fixed_factor_clk_setup(node);
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200198}
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200199CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
200 of_fixed_factor_clk_setup);
Ricardo Ribalda Delgado971451b2016-07-05 18:23:33 +0200201
202static 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
211static 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
228static const struct of_device_id of_fixed_factor_clk_ids[] = {
229 { .compatible = "fixed-factor-clock" },
230 { }
231};
232MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
233
234static 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};
242builtin_platform_driver(of_fixed_factor_clk_driver);
Gregory CLEMENT79b16642013-04-12 13:57:44 +0200243#endif