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 int clk_factor_determine_rate(struct clk_hw *hw,
34 struct clk_rate_request *req)
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 = (req->rate / fix->mult) * fix->div;
42 req->best_parent_rate = clk_hw_round_rate(hw: clk_hw_get_parent(hw), rate: best_parent);
43 }
44
45 req->rate = (req->best_parent_rate / fix->div) * fix->mult;
46
47 return 0;
48}
49
50static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
51 unsigned long parent_rate)
52{
53 /*
54 * We must report success but we can do so unconditionally because
55 * clk_factor_determine_rate returns values that ensure this call is a
56 * nop.
57 */
58
59 return 0;
60}
61
62static unsigned long clk_factor_recalc_accuracy(struct clk_hw *hw,
63 unsigned long parent_accuracy)
64{
65 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
66
67 if (fix->flags & CLK_FIXED_FACTOR_FIXED_ACCURACY)
68 return fix->acc;
69
70 return parent_accuracy;
71}
72
73const struct clk_ops clk_fixed_factor_ops = {
74 .determine_rate = clk_factor_determine_rate,
75 .set_rate = clk_factor_set_rate,
76 .recalc_rate = clk_factor_recalc_rate,
77 .recalc_accuracy = clk_factor_recalc_accuracy,
78};
79EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
80
81static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res)
82{
83 struct clk_fixed_factor *fix = res;
84
85 /*
86 * We can not use clk_hw_unregister_fixed_factor, since it will kfree()
87 * the hw, resulting in double free. Just unregister the hw and let
88 * devres code kfree() it.
89 */
90 clk_hw_unregister(hw: &fix->hw);
91}
92
93static struct clk_hw *
94__clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
95 const char *name, const char *parent_name,
96 const struct clk_hw *parent_hw, const struct clk_parent_data *pdata,
97 unsigned long flags, unsigned int mult, unsigned int div,
98 unsigned long acc, unsigned int fixflags, bool devm)
99{
100 struct clk_fixed_factor *fix;
101 struct clk_init_data init = { };
102 struct clk_hw *hw;
103 int ret;
104
105 /* You can't use devm without a dev */
106 if (devm && !dev)
107 return ERR_PTR(error: -EINVAL);
108
109 if (devm)
110 fix = devres_alloc(devm_clk_hw_register_fixed_factor_release,
111 sizeof(*fix), GFP_KERNEL);
112 else
113 fix = kmalloc(sizeof(*fix), GFP_KERNEL);
114 if (!fix)
115 return ERR_PTR(error: -ENOMEM);
116
117 /* struct clk_fixed_factor assignments */
118 fix->mult = mult;
119 fix->div = div;
120 fix->hw.init = &init;
121 fix->acc = acc;
122 fix->flags = fixflags;
123
124 init.name = name;
125 init.ops = &clk_fixed_factor_ops;
126 init.flags = flags;
127 if (parent_name)
128 init.parent_names = &parent_name;
129 else if (parent_hw)
130 init.parent_hws = &parent_hw;
131 else
132 init.parent_data = pdata;
133 init.num_parents = 1;
134
135 hw = &fix->hw;
136 if (dev)
137 ret = clk_hw_register(dev, hw);
138 else
139 ret = of_clk_hw_register(node: np, hw);
140 if (ret) {
141 if (devm)
142 devres_free(res: fix);
143 else
144 kfree(objp: fix);
145 hw = ERR_PTR(error: ret);
146 } else if (devm)
147 devres_add(dev, res: fix);
148
149 return hw;
150}
151
152/**
153 * devm_clk_hw_register_fixed_factor_index - Register a fixed factor clock with
154 * parent from DT index
155 * @dev: device that is registering this clock
156 * @name: name of this clock
157 * @index: index of phandle in @dev 'clocks' property
158 * @flags: fixed factor flags
159 * @mult: multiplier
160 * @div: divider
161 *
162 * Return: Pointer to fixed factor clk_hw structure that was registered or
163 * an error pointer.
164 */
165struct clk_hw *devm_clk_hw_register_fixed_factor_index(struct device *dev,
166 const char *name, unsigned int index, unsigned long flags,
167 unsigned int mult, unsigned int div)
168{
169 const struct clk_parent_data pdata = { .index = index };
170
171 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, pdata: &pdata,
172 flags, mult, div, acc: 0, fixflags: 0, devm: true);
173}
174EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_index);
175
176/**
177 * devm_clk_hw_register_fixed_factor_parent_hw - Register a fixed factor clock with
178 * pointer to parent clock
179 * @dev: device that is registering this clock
180 * @name: name of this clock
181 * @parent_hw: pointer to parent clk
182 * @flags: fixed factor flags
183 * @mult: multiplier
184 * @div: divider
185 *
186 * Return: Pointer to fixed factor clk_hw structure that was registered or
187 * an error pointer.
188 */
189struct clk_hw *devm_clk_hw_register_fixed_factor_parent_hw(struct device *dev,
190 const char *name, const struct clk_hw *parent_hw,
191 unsigned long flags, unsigned int mult, unsigned int div)
192{
193 const struct clk_parent_data pdata = { .index = -1 };
194
195 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw,
196 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: true);
197}
198EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_parent_hw);
199
200struct clk_hw *clk_hw_register_fixed_factor_parent_hw(struct device *dev,
201 const char *name, const struct clk_hw *parent_hw,
202 unsigned long flags, unsigned int mult, unsigned int div)
203{
204 const struct clk_parent_data pdata = { .index = -1 };
205
206 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw,
207 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: false);
208}
209EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_parent_hw);
210
211struct clk_hw *clk_hw_register_fixed_factor(struct device *dev,
212 const char *name, const char *parent_name, unsigned long flags,
213 unsigned int mult, unsigned int div)
214{
215 const struct clk_parent_data pdata = { .index = -1 };
216
217 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL,
218 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: false);
219}
220EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);
221
222struct clk_hw *clk_hw_register_fixed_factor_fwname(struct device *dev,
223 struct device_node *np, const char *name, const char *fw_name,
224 unsigned long flags, unsigned int mult, unsigned int div)
225{
226 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
227
228 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
229 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: false);
230}
231EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_fwname);
232
233struct clk_hw *clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev,
234 struct device_node *np, const char *name, const char *fw_name,
235 unsigned long flags, unsigned int mult, unsigned int div,
236 unsigned long acc)
237{
238 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
239
240 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
241 pdata: &pdata, flags, mult, div, acc,
242 CLK_FIXED_FACTOR_FIXED_ACCURACY, devm: false);
243}
244EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_with_accuracy_fwname);
245
246struct clk_hw *clk_hw_register_fixed_factor_index(struct device *dev,
247 const char *name, unsigned int index, unsigned long flags,
248 unsigned int mult, unsigned int div)
249{
250 const struct clk_parent_data pdata = { .index = index };
251
252 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, pdata: &pdata,
253 flags, mult, div, acc: 0, fixflags: 0, devm: false);
254}
255EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_index);
256
257struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
258 const char *parent_name, unsigned long flags,
259 unsigned int mult, unsigned int div)
260{
261 struct clk_hw *hw;
262
263 hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult,
264 div);
265 if (IS_ERR(ptr: hw))
266 return ERR_CAST(ptr: hw);
267 return hw->clk;
268}
269EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
270
271void clk_unregister_fixed_factor(struct clk *clk)
272{
273 struct clk_hw *hw;
274
275 hw = __clk_get_hw(clk);
276 if (!hw)
277 return;
278
279 clk_unregister(clk);
280 kfree(to_clk_fixed_factor(hw));
281}
282EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
283
284void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
285{
286 struct clk_fixed_factor *fix;
287
288 fix = to_clk_fixed_factor(hw);
289
290 clk_hw_unregister(hw);
291 kfree(objp: fix);
292}
293EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
294
295struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
296 const char *name, const char *parent_name, unsigned long flags,
297 unsigned int mult, unsigned int div)
298{
299 const struct clk_parent_data pdata = { .index = -1 };
300
301 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL,
302 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: true);
303}
304EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);
305
306struct clk_hw *devm_clk_hw_register_fixed_factor_fwname(struct device *dev,
307 struct device_node *np, const char *name, const char *fw_name,
308 unsigned long flags, unsigned int mult, unsigned int div)
309{
310 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
311
312 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
313 pdata: &pdata, flags, mult, div, acc: 0, fixflags: 0, devm: true);
314}
315EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_fwname);
316
317struct clk_hw *devm_clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev,
318 struct device_node *np, const char *name, const char *fw_name,
319 unsigned long flags, unsigned int mult, unsigned int div,
320 unsigned long acc)
321{
322 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
323
324 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
325 pdata: &pdata, flags, mult, div, acc,
326 CLK_FIXED_FACTOR_FIXED_ACCURACY, devm: true);
327}
328EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_with_accuracy_fwname);
329
330#ifdef CONFIG_OF
331static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
332{
333 struct clk_hw *hw;
334 const char *clk_name = node->name;
335 const struct clk_parent_data pdata = { .index = 0 };
336 u32 div, mult;
337 int ret;
338
339 if (of_property_read_u32(np: node, propname: "clock-div", out_value: &div)) {
340 pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n",
341 __func__, node);
342 return ERR_PTR(error: -EIO);
343 }
344
345 if (of_property_read_u32(np: node, propname: "clock-mult", out_value: &mult)) {
346 pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n",
347 __func__, node);
348 return ERR_PTR(error: -EIO);
349 }
350
351 of_property_read_string(np: node, propname: "clock-output-names", out_string: &clk_name);
352
353 hw = __clk_hw_register_fixed_factor(NULL, np: node, name: clk_name, NULL, NULL,
354 pdata: &pdata, flags: 0, mult, div, acc: 0, fixflags: 0, devm: false);
355 if (IS_ERR(ptr: hw)) {
356 /*
357 * Clear OF_POPULATED flag so that clock registration can be
358 * attempted again from probe function.
359 */
360 of_node_clear_flag(n: node, OF_POPULATED);
361 return ERR_CAST(ptr: hw);
362 }
363
364 ret = of_clk_add_hw_provider(np: node, get: of_clk_hw_simple_get, data: hw);
365 if (ret) {
366 clk_hw_unregister_fixed_factor(hw);
367 return ERR_PTR(error: ret);
368 }
369
370 return hw;
371}
372
373/**
374 * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
375 * @node: device node for the clock
376 */
377void __init of_fixed_factor_clk_setup(struct device_node *node)
378{
379 _of_fixed_factor_clk_setup(node);
380}
381CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
382 of_fixed_factor_clk_setup);
383
384static void of_fixed_factor_clk_remove(struct platform_device *pdev)
385{
386 struct clk_hw *clk = platform_get_drvdata(pdev);
387
388 of_clk_del_provider(np: pdev->dev.of_node);
389 clk_hw_unregister_fixed_factor(clk);
390}
391
392static int of_fixed_factor_clk_probe(struct platform_device *pdev)
393{
394 struct clk_hw *clk;
395
396 /*
397 * This function is not executed when of_fixed_factor_clk_setup
398 * succeeded.
399 */
400 clk = _of_fixed_factor_clk_setup(node: pdev->dev.of_node);
401 if (IS_ERR(ptr: clk))
402 return PTR_ERR(ptr: clk);
403
404 platform_set_drvdata(pdev, data: clk);
405
406 return 0;
407}
408
409static const struct of_device_id of_fixed_factor_clk_ids[] = {
410 { .compatible = "fixed-factor-clock" },
411 { }
412};
413MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
414
415static struct platform_driver of_fixed_factor_clk_driver = {
416 .driver = {
417 .name = "of_fixed_factor_clk",
418 .of_match_table = of_fixed_factor_clk_ids,
419 },
420 .probe = of_fixed_factor_clk_probe,
421 .remove = of_fixed_factor_clk_remove,
422};
423builtin_platform_driver(of_fixed_factor_clk_driver);
424#endif
425

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