1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
5 #include <linux/module.h>
6 #include <linux/clk-provider.h>
7 #include <linux/slab.h>
10 #include <linux/platform_device.h>
13 * DOC: basic fixed multiplier and divider clock that cannot gate
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
22 static unsigned long clk_factor_recalc_rate(struct clk_hw *hw,
23 unsigned long parent_rate)
25 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
26 unsigned long long int rate;
28 rate = (unsigned long long int)parent_rate * fix->mult;
29 do_div(rate, fix->div);
30 return (unsigned long)rate;
33 static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate,
36 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
38 if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
39 unsigned long best_parent;
41 best_parent = (rate / fix->mult) * fix->div;
42 *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
45 return (*prate / fix->div) * fix->mult;
48 static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
49 unsigned long parent_rate)
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
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,
65 EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
67 static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res)
69 clk_hw_unregister_fixed_factor(&((struct clk_fixed_factor *)res)->hw);
72 static struct clk_hw *
73 __clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
74 const char *name, const char *parent_name, int index,
75 unsigned long flags, unsigned int mult, unsigned int div,
78 struct clk_fixed_factor *fix;
79 struct clk_init_data init = { };
80 struct clk_parent_data pdata = { .index = index };
84 /* You can't use devm without a dev */
86 return ERR_PTR(-EINVAL);
89 fix = devres_alloc(devm_clk_hw_register_fixed_factor_release,
90 sizeof(*fix), GFP_KERNEL);
92 fix = kmalloc(sizeof(*fix), GFP_KERNEL);
94 return ERR_PTR(-ENOMEM);
96 /* struct clk_fixed_factor assignments */
102 init.ops = &clk_fixed_factor_ops;
105 init.parent_names = &parent_name;
107 init.parent_data = &pdata;
108 init.num_parents = 1;
112 ret = clk_hw_register(dev, hw);
114 ret = of_clk_hw_register(np, hw);
122 devres_add(dev, fix);
127 struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
128 const char *name, const char *parent_name, unsigned long flags,
129 unsigned int mult, unsigned int div)
131 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, -1,
132 flags, mult, div, false);
134 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
136 struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
137 const char *parent_name, unsigned long flags,
138 unsigned int mult, unsigned int div)
142 hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult,
148 EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
150 void clk_unregister_fixed_factor(struct clk *clk)
154 hw = __clk_get_hw(clk);
159 kfree(to_clk_fixed_factor(hw));
161 EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
163 void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
165 struct clk_fixed_factor *fix;
167 fix = to_clk_fixed_factor(hw);
169 clk_hw_unregister(hw);
172 EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
174 struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
175 const char *name, const char *parent_name, unsigned long flags,
176 unsigned int mult, unsigned int div)
178 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, -1,
179 flags, mult, div, true);
181 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);
184 static const struct of_device_id set_rate_parent_matches[] = {
185 { .compatible = "allwinner,sun4i-a10-pll3-2x-clk" },
189 static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
192 const char *clk_name = node->name;
193 unsigned long flags = 0;
197 if (of_property_read_u32(node, "clock-div", &div)) {
198 pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n",
200 return ERR_PTR(-EIO);
203 if (of_property_read_u32(node, "clock-mult", &mult)) {
204 pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n",
206 return ERR_PTR(-EIO);
209 of_property_read_string(node, "clock-output-names", &clk_name);
211 if (of_match_node(set_rate_parent_matches, node))
212 flags |= CLK_SET_RATE_PARENT;
214 hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, 0,
215 flags, mult, div, false);
218 * Clear OF_POPULATED flag so that clock registration can be
219 * attempted again from probe function.
221 of_node_clear_flag(node, OF_POPULATED);
225 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
227 clk_hw_unregister_fixed_factor(hw);
235 * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
236 * @node: device node for the clock
238 void __init of_fixed_factor_clk_setup(struct device_node *node)
240 _of_fixed_factor_clk_setup(node);
242 CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
243 of_fixed_factor_clk_setup);
245 static int of_fixed_factor_clk_remove(struct platform_device *pdev)
247 struct clk_hw *clk = platform_get_drvdata(pdev);
249 of_clk_del_provider(pdev->dev.of_node);
250 clk_hw_unregister_fixed_factor(clk);
255 static int of_fixed_factor_clk_probe(struct platform_device *pdev)
260 * This function is not executed when of_fixed_factor_clk_setup
263 clk = _of_fixed_factor_clk_setup(pdev->dev.of_node);
267 platform_set_drvdata(pdev, clk);
272 static const struct of_device_id of_fixed_factor_clk_ids[] = {
273 { .compatible = "fixed-factor-clock" },
276 MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
278 static struct platform_driver of_fixed_factor_clk_driver = {
280 .name = "of_fixed_factor_clk",
281 .of_match_table = of_fixed_factor_clk_ids,
283 .probe = of_fixed_factor_clk_probe,
284 .remove = of_fixed_factor_clk_remove,
286 builtin_platform_driver(of_fixed_factor_clk_driver);