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(hw: clk_hw_get_parent(hw), rate: 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
60static unsigned long clk_factor_recalc_accuracy(struct clk_hw *hw,
61 unsigned long parent_accuracy)
62{
63 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
64
65 if (fix->flags & CLK_FIXED_FACTOR_FIXED_ACCURACY)
66 return fix->acc;
67
68 return parent_accuracy;
69}
70
71const struct clk_ops clk_fixed_factor_ops = {
72 .round_rate = clk_factor_round_rate,
73 .set_rate = clk_factor_set_rate,
74 .recalc_rate = clk_factor_recalc_rate,
75 .recalc_accuracy = clk_factor_recalc_accuracy,
76};
77EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
78
79static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res)
80{
81 struct clk_fixed_factor *fix = res;
82
83 /*
84 * We can not use clk_hw_unregister_fixed_factor, since it will kfree()
85 * the hw, resulting in double free. Just unregister the hw and let
86 * devres code kfree() it.
87 */
88 clk_hw_unregister(hw: &fix->hw);
89}
90
91static struct clk_hw *
92__clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
93 const char *name, const char *parent_name,
94 const struct clk_hw *parent_hw, const struct clk_parent_data *pdata,
95 unsigned long flags, unsigned int mult, unsigned int div,
96 unsigned long acc, unsigned int fixflags, bool devm)
97{
98 struct clk_fixed_factor *fix;
99 struct clk_init_data init = { };
100 struct clk_hw *hw;
101 int ret;
102
103 /* You can't use devm without a dev */
104 if (devm && !dev)
105 return ERR_PTR(error: -EINVAL);
106
107 if (devm)
108 fix = devres_alloc(devm_clk_hw_register_fixed_factor_release,
109 sizeof(*fix), GFP_KERNEL);
110 else
111 fix = kmalloc(size: sizeof(*fix), GFP_KERNEL);
112 if (!fix)
113 return ERR_PTR(error: -ENOMEM);
114
115 /* struct clk_fixed_factor assignments */
116 fix->mult = mult;
117 fix->div = div;
118 fix->hw.init = &init;
119 fix->acc = acc;
120 fix->flags = fixflags;
121
122 init.name = name;
123 init.ops = &clk_fixed_factor_ops;
124 init.flags = flags;
125 if (parent_name)
126 init.parent_names = &parent_name;
127 else if (parent_hw)
128 init.parent_hws = &parent_hw;
129 else
130 init.parent_data = pdata;
131 init.num_parents = 1;
132
133 hw = &fix->hw;
134 if (dev)
135 ret = clk_hw_register(dev, hw);
136 else
137 ret = of_clk_hw_register(node: np, hw);
138 if (ret) {
139 if (devm)
140 devres_free(res: fix);
141 else
142 kfree(objp: fix);
143 hw = ERR_PTR(error: ret);
144 } else if (devm)
145 devres_add(dev, res: fix);
146
147 return hw;
148}
149
150/**
151 * devm_clk_hw_register_fixed_factor_index - Register a fixed factor clock with
152 * parent from DT index
153 * @dev: device that is registering this clock
154 * @name: name of this clock
155 * @index: index of phandle in @dev 'clocks' property
156 * @flags: fixed factor flags
157 * @mult: multiplier
158 * @div: divider
159 *
160 * Return: Pointer to fixed factor clk_hw structure that was registered or
161 * an error pointer.
162 */
163struct clk_hw *devm_clk_hw_register_fixed_factor_index(struct device *dev,
164 const char *name, unsigned int index, unsigned long flags,
165 unsigned int mult, unsigned int div)
166{
167 const struct clk_parent_data pdata = { .index = index };
168
169 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, pdata: &pdata,
170 flags, mult, div, acc: 0, fixflags: 0, devm: true);
171}
172EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_index);
173
174/**
175 * devm_clk_hw_register_fixed_factor_parent_hw - Register a fixed factor clock with
176 * pointer to parent clock
177 * @dev: device that is registering this clock
178 * @name: name of this clock
179 * @parent_hw: pointer to parent clk
180 * @flags: fixed factor flags
181 * @mult: multiplier
182 * @div: divider
183 *
184 * Return: Pointer to fixed factor clk_hw structure that was registered or
185 * an error pointer.
186 */
187struct clk_hw *devm_clk_hw_register_fixed_factor_parent_hw(struct device *dev,
188 const char *name, const struct clk_hw *parent_hw,
189 unsigned long flags, unsigned int mult, unsigned int div)
190{
191 const struct clk_parent_data pdata = { .index = -1 };
192
193 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw,
194 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: true);
195}
196EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_parent_hw);
197
198struct clk_hw *clk_hw_register_fixed_factor_parent_hw(struct device *dev,
199 const char *name, const struct clk_hw *parent_hw,
200 unsigned long flags, unsigned int mult, unsigned int div)
201{
202 const struct clk_parent_data pdata = { .index = -1 };
203
204 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw,
205 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: false);
206}
207EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_parent_hw);
208
209struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
210 const char *name, const char *parent_name, unsigned long flags,
211 unsigned int mult, unsigned int div)
212{
213 const struct clk_parent_data pdata = { .index = -1 };
214
215 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL,
216 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: false);
217}
218EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
219
220struct clk_hw *clk_hw_register_fixed_factor_fwname(struct device *dev,
221 struct device_node *np, const char *name, const char *fw_name,
222 unsigned long flags, unsigned int mult, unsigned int div)
223{
224 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
225
226 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
227 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: false);
228}
229EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_fwname);
230
231struct clk_hw *clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev,
232 struct device_node *np, const char *name, const char *fw_name,
233 unsigned long flags, unsigned int mult, unsigned int div,
234 unsigned long acc)
235{
236 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
237
238 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
239 pdata: &pdata, flags, mult, div, acc,
240 CLK_FIXED_FACTOR_FIXED_ACCURACY, devm: false);
241}
242EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_with_accuracy_fwname);
243
244struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
245 const char *parent_name, unsigned long flags,
246 unsigned int mult, unsigned int div)
247{
248 struct clk_hw *hw;
249
250 hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult,
251 div);
252 if (IS_ERR(ptr: hw))
253 return ERR_CAST(ptr: hw);
254 return hw->clk;
255}
256EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
257
258void clk_unregister_fixed_factor(struct clk *clk)
259{
260 struct clk_hw *hw;
261
262 hw = __clk_get_hw(clk);
263 if (!hw)
264 return;
265
266 clk_unregister(clk);
267 kfree(to_clk_fixed_factor(hw));
268}
269EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
270
271void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
272{
273 struct clk_fixed_factor *fix;
274
275 fix = to_clk_fixed_factor(hw);
276
277 clk_hw_unregister(hw);
278 kfree(objp: fix);
279}
280EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
281
282struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
283 const char *name, const char *parent_name, unsigned long flags,
284 unsigned int mult, unsigned int div)
285{
286 const struct clk_parent_data pdata = { .index = -1 };
287
288 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL,
289 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: true);
290}
291EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);
292
293struct clk_hw *devm_clk_hw_register_fixed_factor_fwname(struct device *dev,
294 struct device_node *np, const char *name, const char *fw_name,
295 unsigned long flags, unsigned int mult, unsigned int div)
296{
297 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
298
299 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
300 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: true);
301}
302EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_fwname);
303
304struct clk_hw *devm_clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev,
305 struct device_node *np, const char *name, const char *fw_name,
306 unsigned long flags, unsigned int mult, unsigned int div,
307 unsigned long acc)
308{
309 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
310
311 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
312 pdata: &pdata, flags, mult, div, acc,
313 CLK_FIXED_FACTOR_FIXED_ACCURACY, devm: true);
314}
315EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_with_accuracy_fwname);
316
317#ifdef CONFIG_OF
318static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
319{
320 struct clk_hw *hw;
321 const char *clk_name = node->name;
322 const struct clk_parent_data pdata = { .index = 0 };
323 u32 div, mult;
324 int ret;
325
326 if (of_property_read_u32(np: node, propname: "clock-div", out_value: &div)) {
327 pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n",
328 __func__, node);
329 return ERR_PTR(error: -EIO);
330 }
331
332 if (of_property_read_u32(np: node, propname: "clock-mult", out_value: &mult)) {
333 pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n",
334 __func__, node);
335 return ERR_PTR(error: -EIO);
336 }
337
338 of_property_read_string(np: node, propname: "clock-output-names", out_string: &clk_name);
339
340 hw = __clk_hw_register_fixed_factor(NULL, np: node, name: clk_name, NULL, NULL,
341 pdata: &pdata, flags: 0, mult, div, acc: 0, fixflags: 0, devm: false);
342 if (IS_ERR(ptr: hw)) {
343 /*
344 * Clear OF_POPULATED flag so that clock registration can be
345 * attempted again from probe function.
346 */
347 of_node_clear_flag(n: node, OF_POPULATED);
348 return ERR_CAST(ptr: hw);
349 }
350
351 ret = of_clk_add_hw_provider(np: node, get: of_clk_hw_simple_get, data: hw);
352 if (ret) {
353 clk_hw_unregister_fixed_factor(hw);
354 return ERR_PTR(error: ret);
355 }
356
357 return hw;
358}
359
360/**
361 * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
362 * @node: device node for the clock
363 */
364void __init of_fixed_factor_clk_setup(struct device_node *node)
365{
366 _of_fixed_factor_clk_setup(node);
367}
368CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
369 of_fixed_factor_clk_setup);
370
371static void of_fixed_factor_clk_remove(struct platform_device *pdev)
372{
373 struct clk_hw *clk = platform_get_drvdata(pdev);
374
375 of_clk_del_provider(np: pdev->dev.of_node);
376 clk_hw_unregister_fixed_factor(clk);
377}
378
379static int of_fixed_factor_clk_probe(struct platform_device *pdev)
380{
381 struct clk_hw *clk;
382
383 /*
384 * This function is not executed when of_fixed_factor_clk_setup
385 * succeeded.
386 */
387 clk = _of_fixed_factor_clk_setup(node: pdev->dev.of_node);
388 if (IS_ERR(ptr: clk))
389 return PTR_ERR(ptr: clk);
390
391 platform_set_drvdata(pdev, data: clk);
392
393 return 0;
394}
395
396static const struct of_device_id of_fixed_factor_clk_ids[] = {
397 { .compatible = "fixed-factor-clock" },
398 { }
399};
400MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
401
402static struct platform_driver of_fixed_factor_clk_driver = {
403 .driver = {
404 .name = "of_fixed_factor_clk",
405 .of_match_table = of_fixed_factor_clk_ids,
406 },
407 .probe = of_fixed_factor_clk_probe,
408 .remove_new = of_fixed_factor_clk_remove,
409};
410builtin_platform_driver(of_fixed_factor_clk_driver);
411#endif
412

source code of linux/drivers/clk/clk-fixed-factor.c