projects/linux·blob master · refs

372 lines · 10.2 KiB

1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2011 Sascha Hauer, Pengutronix <[email protected]>
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 struct clk_hw *parent_hw = clk_hw_get_parent(hw);
40 unsigned long best_parent;
41
42 if (!parent_hw)
43 return -EINVAL;
44
45 best_parent = (req->rate / fix->mult) * fix->div;
46 req->best_parent_rate = clk_hw_round_rate(parent_hw, best_parent);
47 }
48
49 req->rate = (req->best_parent_rate / fix->div) * fix->mult;
50
51 return 0;
52}
53
54static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
55 unsigned long parent_rate)
56{
57 /*
58 * We must report success but we can do so unconditionally because
59 * clk_factor_determine_rate returns values that ensure this call is a
60 * nop.
61 */
62
63 return 0;
64}
65
66static unsigned long clk_factor_recalc_accuracy(struct clk_hw *hw,
67 unsigned long parent_accuracy)
68{
69 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw);
70
71 if (fix->flags & CLK_FIXED_FACTOR_FIXED_ACCURACY)
72 return fix->acc;
73
74 return parent_accuracy;
75}
76
77const struct clk_ops clk_fixed_factor_ops = {
78 .determine_rate = clk_factor_determine_rate,
79 .set_rate = clk_factor_set_rate,
80 .recalc_rate = clk_factor_recalc_rate,
81 .recalc_accuracy = clk_factor_recalc_accuracy,
82};
83EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);
84
85static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res)
86{
87 struct clk_fixed_factor *fix = res;
88
89 /*
90 * We can not use clk_hw_unregister_fixed_factor, since it will kfree()
91 * the hw, resulting in double free. Just unregister the hw and let
92 * devres code kfree() it.
93 */
94 clk_hw_unregister(&fix->hw);
95}
96
97struct clk_hw *
98__clk_hw_register_fixed_factor(struct device *dev, struct device_node *np,
99 const char *name, const char *parent_name,
100 const struct clk_hw *parent_hw, const struct clk_parent_data *pdata,
101 unsigned long flags, unsigned int mult, unsigned int div,
102 unsigned long acc, unsigned int fixflags, bool devm)
103{
104 struct clk_fixed_factor *fix;
105 struct clk_init_data init = { };
106 struct clk_hw *hw;
107 int ret;
108
109 /* You can't use devm without a dev */
110 if (devm && !dev)
111 return ERR_PTR(-EINVAL);
112
113 if (devm)
114 fix = devres_alloc(devm_clk_hw_register_fixed_factor_release,
115 sizeof(*fix), GFP_KERNEL);
116 else
117 fix = kmalloc_obj(*fix);
118 if (!fix)
119 return ERR_PTR(-ENOMEM);
120
121 /* struct clk_fixed_factor assignments */
122 fix->mult = mult;
123 fix->div = div;
124 fix->hw.init = &init;
125 fix->acc = acc;
126 fix->flags = fixflags;
127
128 init.name = name;
129 init.ops = &clk_fixed_factor_ops;
130 init.flags = flags;
131 init.parent_names = parent_name ? &parent_name : NULL;
132 init.parent_hws = parent_hw ? &parent_hw : NULL;
133 init.parent_data = pdata;
134 if (parent_name || parent_hw || pdata)
135 init.num_parents = 1;
136 else
137 init.num_parents = 0;
138
139 hw = &fix->hw;
140 if (dev)
141 ret = clk_hw_register(dev, hw);
142 else
143 ret = of_clk_hw_register(np, hw);
144 if (ret) {
145 if (devm)
146 devres_free(fix);
147 else
148 kfree(fix);
149 hw = ERR_PTR(ret);
150 } else if (devm)
151 devres_add(dev, fix);
152
153 return hw;
154}
155EXPORT_SYMBOL_GPL(__clk_hw_register_fixed_factor);
156
157/**
158 * devm_clk_hw_register_fixed_factor_index - Register a fixed factor clock with
159 * parent from DT index
160 * @dev: device that is registering this clock
161 * @name: name of this clock
162 * @index: index of phandle in @dev 'clocks' property
163 * @flags: fixed factor flags
164 * @mult: multiplier
165 * @div: divider
166 *
167 * Return: Pointer to fixed factor clk_hw structure that was registered or
168 * an error pointer.
169 */
170struct clk_hw *devm_clk_hw_register_fixed_factor_index(struct device *dev,
171 const char *name, unsigned int index, unsigned long flags,
172 unsigned int mult, unsigned int div)
173{
174 const struct clk_parent_data pdata = { .index = index };
175
176 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, &pdata,
177 flags, mult, div, 0, 0, true);
178}
179EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_index);
180
181struct clk_hw *clk_hw_register_fixed_factor_fwname(struct device *dev,
182 struct device_node *np, const char *name, const char *fw_name,
183 unsigned long flags, unsigned int mult, unsigned int div)
184{
185 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
186
187 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
188 &pdata, flags, mult, div, 0, 0, false);
189}
190EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_fwname);
191
192struct clk_hw *clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev,
193 struct device_node *np, const char *name, const char *fw_name,
194 unsigned long flags, unsigned int mult, unsigned int div,
195 unsigned long acc)
196{
197 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
198
199 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
200 &pdata, flags, mult, div, acc,
201 CLK_FIXED_FACTOR_FIXED_ACCURACY, false);
202}
203EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_with_accuracy_fwname);
204
205struct clk_hw *clk_hw_register_fixed_factor_index(struct device *dev,
206 const char *name, unsigned int index, unsigned long flags,
207 unsigned int mult, unsigned int div)
208{
209 const struct clk_parent_data pdata = { .index = index };
210
211 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, &pdata,
212 flags, mult, div, 0, 0, false);
213}
214EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_index);
215
216struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
217 const char *parent_name, unsigned long flags,
218 unsigned int mult, unsigned int div)
219{
220 struct clk_hw *hw;
221
222 hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult,
223 div);
224 if (IS_ERR(hw))
225 return ERR_CAST(hw);
226 return hw->clk;
227}
228EXPORT_SYMBOL_GPL(clk_register_fixed_factor);
229
230void clk_unregister_fixed_factor(struct clk *clk)
231{
232 struct clk_hw *hw;
233
234 hw = __clk_get_hw(clk);
235 if (!hw)
236 return;
237
238 clk_unregister(clk);
239 kfree(to_clk_fixed_factor(hw));
240}
241EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);
242
243void clk_hw_unregister_fixed_factor(struct clk_hw *hw)
244{
245 struct clk_fixed_factor *fix;
246
247 fix = to_clk_fixed_factor(hw);
248
249 clk_hw_unregister(hw);
250 kfree(fix);
251}
252EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);
253
254struct clk_hw *devm_clk_hw_register_fixed_factor_fwname(struct device *dev,
255 struct device_node *np, const char *name, const char *fw_name,
256 unsigned long flags, unsigned int mult, unsigned int div)
257{
258 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
259
260 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
261 &pdata, flags, mult, div, 0, 0, true);
262}
263EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_fwname);
264
265struct clk_hw *devm_clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev,
266 struct device_node *np, const char *name, const char *fw_name,
267 unsigned long flags, unsigned int mult, unsigned int div,
268 unsigned long acc)
269{
270 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name };
271
272 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL,
273 &pdata, flags, mult, div, acc,
274 CLK_FIXED_FACTOR_FIXED_ACCURACY, true);
275}
276EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_with_accuracy_fwname);
277
278#ifdef CONFIG_OF
279static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node)
280{
281 struct clk_hw *hw;
282 const char *clk_name = node->name;
283 const struct clk_parent_data pdata = { .index = 0 };
284 u32 div, mult;
285 int ret;
286
287 if (of_property_read_u32(node, "clock-div", &div)) {
288 pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n",
289 __func__, node);
290 return ERR_PTR(-EIO);
291 }
292
293 if (of_property_read_u32(node, "clock-mult", &mult)) {
294 pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n",
295 __func__, node);
296 return ERR_PTR(-EIO);
297 }
298
299 of_property_read_string(node, "clock-output-names", &clk_name);
300
301 hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, NULL,
302 &pdata, 0, mult, div, 0, 0, false);
303 if (IS_ERR(hw)) {
304 /*
305 * Clear OF_POPULATED flag so that clock registration can be
306 * attempted again from probe function.
307 */
308 of_node_clear_flag(node, OF_POPULATED);
309 return ERR_CAST(hw);
310 }
311
312 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
313 if (ret) {
314 clk_hw_unregister_fixed_factor(hw);
315 return ERR_PTR(ret);
316 }
317
318 return hw;
319}
320
321/**
322 * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock
323 * @node: device node for the clock
324 */
325void __init of_fixed_factor_clk_setup(struct device_node *node)
326{
327 _of_fixed_factor_clk_setup(node);
328}
329CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",
330 of_fixed_factor_clk_setup);
331
332static void of_fixed_factor_clk_remove(struct platform_device *pdev)
333{
334 struct clk_hw *clk = platform_get_drvdata(pdev);
335
336 of_clk_del_provider(pdev->dev.of_node);
337 clk_hw_unregister_fixed_factor(clk);
338}
339
340static int of_fixed_factor_clk_probe(struct platform_device *pdev)
341{
342 struct clk_hw *clk;
343
344 /*
345 * This function is not executed when of_fixed_factor_clk_setup
346 * succeeded.
347 */
348 clk = _of_fixed_factor_clk_setup(pdev->dev.of_node);
349 if (IS_ERR(clk))
350 return PTR_ERR(clk);
351
352 platform_set_drvdata(pdev, clk);
353
354 return 0;
355}
356
357static const struct of_device_id of_fixed_factor_clk_ids[] = {
358 { .compatible = "fixed-factor-clock" },
359 { }
360};
361MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);
362
363static struct platform_driver of_fixed_factor_clk_driver = {
364 .driver = {
365 .name = "of_fixed_factor_clk",
366 .of_match_table = of_fixed_factor_clk_ids,
367 },
368 .probe = of_fixed_factor_clk_probe,
369 .remove = of_fixed_factor_clk_remove,
370};
371builtin_platform_driver(of_fixed_factor_clk_driver);
372#endif