Loading...
Note: File does not exist in v3.1.
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
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(&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(-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(sizeof(*fix), GFP_KERNEL);
112 if (!fix)
113 return ERR_PTR(-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(np, hw);
138 if (ret) {
139 if (devm)
140 devres_free(fix);
141 else
142 kfree(fix);
143 hw = ERR_PTR(ret);
144 } else if (devm)
145 devres_add(dev, 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,
170 flags, mult, div, 0, 0, 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, flags, mult, div, 0, 0, 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, flags, mult, div, 0, 0, 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, flags, mult, div, 0, 0, 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, flags, mult, div, 0, 0, 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, flags, mult, div, acc,
240 CLK_FIXED_FACTOR_FIXED_ACCURACY, false);
241}
242EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_with_accuracy_fwname);
243
244struct clk_hw *clk_hw_register_fixed_factor_index(struct device *dev,
245 const char *name, unsigned int index, unsigned long flags,
246 unsigned int mult, unsigned int div)
247{
248 const struct clk_parent_data pdata = { .index = index };
249
250 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, &pdata,
251 flags, mult, div, 0, 0, false);
252}
253EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_index);
254
255struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
256 const char *parent_name, unsigned long flags,
257 unsigned int mult, unsigned int div)
258{
259 struct clk_hw *hw;
260
261 hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult,
262 div);
263 if (IS_ERR(hw))
264 return ERR_CAST(hw);
265 return hw->clk;
266}
267EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
268
269void clk_unregister_fixed_factor(struct clk *clk)
270{
271 struct clk_hw *hw;
272
273 hw = __clk_get_hw(clk);
274 if (!hw)
275 return;
276
277 clk_unregister(clk);
278 kfree(to_clk_fixed_factor(hw));
279}
280EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
281
282void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
283{
284 struct clk_fixed_factor *fix;
285
286 fix = to_clk_fixed_factor(hw);
287
288 clk_hw_unregister(hw);
289 kfree(fix);
290}
291EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
292
293struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev,
294 const char *name, const char *parent_name, unsigned long flags,
295 unsigned int mult, unsigned int div)
296{
297 const struct clk_parent_data pdata = { .index = -1 };
298
299 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL,
300 &pdata, flags, mult, div, 0, 0, true);
301}
302EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);
303
304struct clk_hw *devm_clk_hw_register_fixed_factor_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{
308 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
309
310 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
311 &pdata, flags, mult, div, 0, 0, true);
312}
313EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_fwname);
314
315struct clk_hw *devm_clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev,
316 struct device_node *np, const char *name, const char *fw_name,
317 unsigned long flags, unsigned int mult, unsigned int div,
318 unsigned long acc)
319{
320 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
321
322 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
323 &pdata, flags, mult, div, acc,
324 CLK_FIXED_FACTOR_FIXED_ACCURACY, true);
325}
326EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_with_accuracy_fwname);
327
328#ifdef CONFIG_OF
329static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
330{
331 struct clk_hw *hw;
332 const char *clk_name = node->name;
333 const struct clk_parent_data pdata = { .index = 0 };
334 u32 div, mult;
335 int ret;
336
337 if (of_property_read_u32(node, "clock-div", &div)) {
338 pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n",
339 __func__, node);
340 return ERR_PTR(-EIO);
341 }
342
343 if (of_property_read_u32(node, "clock-mult", &mult)) {
344 pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n",
345 __func__, node);
346 return ERR_PTR(-EIO);
347 }
348
349 of_property_read_string(node, "clock-output-names", &clk_name);
350
351 hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, NULL,
352 &pdata, 0, mult, div, 0, 0, false);
353 if (IS_ERR(hw)) {
354 /*
355 * Clear OF_POPULATED flag so that clock registration can be
356 * attempted again from probe function.
357 */
358 of_node_clear_flag(node, OF_POPULATED);
359 return ERR_CAST(hw);
360 }
361
362 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
363 if (ret) {
364 clk_hw_unregister_fixed_factor(hw);
365 return ERR_PTR(ret);
366 }
367
368 return hw;
369}
370
371/**
372 * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
373 * @node: device node for the clock
374 */
375void __init of_fixed_factor_clk_setup(struct device_node *node)
376{
377 _of_fixed_factor_clk_setup(node);
378}
379CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
380 of_fixed_factor_clk_setup);
381
382static void of_fixed_factor_clk_remove(struct platform_device *pdev)
383{
384 struct clk_hw *clk = platform_get_drvdata(pdev);
385
386 of_clk_del_provider(pdev->dev.of_node);
387 clk_hw_unregister_fixed_factor(clk);
388}
389
390static int of_fixed_factor_clk_probe(struct platform_device *pdev)
391{
392 struct clk_hw *clk;
393
394 /*
395 * This function is not executed when of_fixed_factor_clk_setup
396 * succeeded.
397 */
398 clk = _of_fixed_factor_clk_setup(pdev->dev.of_node);
399 if (IS_ERR(clk))
400 return PTR_ERR(clk);
401
402 platform_set_drvdata(pdev, clk);
403
404 return 0;
405}
406
407static const struct of_device_id of_fixed_factor_clk_ids[] = {
408 { .compatible = "fixed-factor-clock" },
409 { }
410};
411MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
412
413static struct platform_driver of_fixed_factor_clk_driver = {
414 .driver = {
415 .name = "of_fixed_factor_clk",
416 .of_match_table = of_fixed_factor_clk_ids,
417 },
418 .probe = of_fixed_factor_clk_probe,
419 .remove = of_fixed_factor_clk_remove,
420};
421builtin_platform_driver(of_fixed_factor_clk_driver);
422#endif