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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
f262f28c CC |
2 | /* |
3 | * devfreq-event: a framework to provide raw data and events of devfreq devices | |
4 | * | |
5 | * Copyright (C) 2015 Samsung Electronics | |
6 | * Author: Chanwoo Choi <cw00.choi@samsung.com> | |
7 | * | |
f262f28c CC |
8 | * This driver is based on drivers/devfreq/devfreq.c. |
9 | */ | |
10 | ||
11 | #include <linux/devfreq-event.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/err.h> | |
14 | #include <linux/init.h> | |
e32363bc | 15 | #include <linux/export.h> |
f262f28c CC |
16 | #include <linux/slab.h> |
17 | #include <linux/list.h> | |
18 | #include <linux/of.h> | |
19 | ||
20 | static struct class *devfreq_event_class; | |
21 | ||
22 | /* The list of all devfreq event list */ | |
23 | static LIST_HEAD(devfreq_event_list); | |
24 | static DEFINE_MUTEX(devfreq_event_list_lock); | |
25 | ||
26 | #define to_devfreq_event(DEV) container_of(DEV, struct devfreq_event_dev, dev) | |
27 | ||
28 | /** | |
29 | * devfreq_event_enable_edev() - Enable the devfreq-event dev and increase | |
30 | * the enable_count of devfreq-event dev. | |
31 | * @edev : the devfreq-event device | |
32 | * | |
33 | * Note that this function increase the enable_count and enable the | |
34 | * devfreq-event device. The devfreq-event device should be enabled before | |
35 | * using it by devfreq device. | |
36 | */ | |
37 | int devfreq_event_enable_edev(struct devfreq_event_dev *edev) | |
38 | { | |
39 | int ret = 0; | |
40 | ||
41 | if (!edev || !edev->desc) | |
42 | return -EINVAL; | |
43 | ||
44 | mutex_lock(&edev->lock); | |
45 | if (edev->desc->ops && edev->desc->ops->enable | |
46 | && edev->enable_count == 0) { | |
47 | ret = edev->desc->ops->enable(edev); | |
48 | if (ret < 0) | |
49 | goto err; | |
50 | } | |
51 | edev->enable_count++; | |
52 | err: | |
53 | mutex_unlock(&edev->lock); | |
54 | ||
55 | return ret; | |
56 | } | |
57 | EXPORT_SYMBOL_GPL(devfreq_event_enable_edev); | |
58 | ||
59 | /** | |
60 | * devfreq_event_disable_edev() - Disable the devfreq-event dev and decrease | |
61 | * the enable_count of the devfreq-event dev. | |
62 | * @edev : the devfreq-event device | |
63 | * | |
64 | * Note that this function decrease the enable_count and disable the | |
65 | * devfreq-event device. After the devfreq-event device is disabled, | |
66 | * devfreq device can't use the devfreq-event device for get/set/reset | |
67 | * operations. | |
68 | */ | |
69 | int devfreq_event_disable_edev(struct devfreq_event_dev *edev) | |
70 | { | |
71 | int ret = 0; | |
72 | ||
73 | if (!edev || !edev->desc) | |
74 | return -EINVAL; | |
75 | ||
76 | mutex_lock(&edev->lock); | |
77 | if (edev->enable_count <= 0) { | |
78 | dev_warn(&edev->dev, "unbalanced enable_count\n"); | |
79 | ret = -EIO; | |
80 | goto err; | |
81 | } | |
82 | ||
83 | if (edev->desc->ops && edev->desc->ops->disable | |
84 | && edev->enable_count == 1) { | |
85 | ret = edev->desc->ops->disable(edev); | |
86 | if (ret < 0) | |
87 | goto err; | |
88 | } | |
89 | edev->enable_count--; | |
90 | err: | |
91 | mutex_unlock(&edev->lock); | |
92 | ||
93 | return ret; | |
94 | } | |
95 | EXPORT_SYMBOL_GPL(devfreq_event_disable_edev); | |
96 | ||
97 | /** | |
98 | * devfreq_event_is_enabled() - Check whether devfreq-event dev is enabled or | |
99 | * not. | |
100 | * @edev : the devfreq-event device | |
101 | * | |
102 | * Note that this function check whether devfreq-event dev is enabled or not. | |
103 | * If return true, the devfreq-event dev is enabeld. If return false, the | |
104 | * devfreq-event dev is disabled. | |
105 | */ | |
106 | bool devfreq_event_is_enabled(struct devfreq_event_dev *edev) | |
107 | { | |
108 | bool enabled = false; | |
109 | ||
110 | if (!edev || !edev->desc) | |
111 | return enabled; | |
112 | ||
113 | mutex_lock(&edev->lock); | |
114 | ||
115 | if (edev->enable_count > 0) | |
116 | enabled = true; | |
117 | ||
118 | mutex_unlock(&edev->lock); | |
119 | ||
120 | return enabled; | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(devfreq_event_is_enabled); | |
123 | ||
124 | /** | |
125 | * devfreq_event_set_event() - Set event to devfreq-event dev to start. | |
126 | * @edev : the devfreq-event device | |
127 | * | |
128 | * Note that this function set the event to the devfreq-event device to start | |
129 | * for getting the event data which could be various event type. | |
130 | */ | |
131 | int devfreq_event_set_event(struct devfreq_event_dev *edev) | |
132 | { | |
133 | int ret; | |
134 | ||
135 | if (!edev || !edev->desc) | |
136 | return -EINVAL; | |
137 | ||
138 | if (!edev->desc->ops || !edev->desc->ops->set_event) | |
139 | return -EINVAL; | |
140 | ||
141 | if (!devfreq_event_is_enabled(edev)) | |
142 | return -EPERM; | |
143 | ||
144 | mutex_lock(&edev->lock); | |
145 | ret = edev->desc->ops->set_event(edev); | |
146 | mutex_unlock(&edev->lock); | |
147 | ||
148 | return ret; | |
149 | } | |
150 | EXPORT_SYMBOL_GPL(devfreq_event_set_event); | |
151 | ||
152 | /** | |
153 | * devfreq_event_get_event() - Get {load|total}_count from devfreq-event dev. | |
154 | * @edev : the devfreq-event device | |
155 | * @edata : the calculated data of devfreq-event device | |
156 | * | |
157 | * Note that this function get the calculated event data from devfreq-event dev | |
158 | * after stoping the progress of whole sequence of devfreq-event dev. | |
159 | */ | |
160 | int devfreq_event_get_event(struct devfreq_event_dev *edev, | |
161 | struct devfreq_event_data *edata) | |
162 | { | |
163 | int ret; | |
164 | ||
165 | if (!edev || !edev->desc) | |
166 | return -EINVAL; | |
167 | ||
168 | if (!edev->desc->ops || !edev->desc->ops->get_event) | |
169 | return -EINVAL; | |
170 | ||
171 | if (!devfreq_event_is_enabled(edev)) | |
172 | return -EINVAL; | |
173 | ||
174 | edata->total_count = edata->load_count = 0; | |
175 | ||
176 | mutex_lock(&edev->lock); | |
177 | ret = edev->desc->ops->get_event(edev, edata); | |
178 | if (ret < 0) | |
179 | edata->total_count = edata->load_count = 0; | |
180 | mutex_unlock(&edev->lock); | |
181 | ||
182 | return ret; | |
183 | } | |
184 | EXPORT_SYMBOL_GPL(devfreq_event_get_event); | |
185 | ||
186 | /** | |
187 | * devfreq_event_reset_event() - Reset all opeations of devfreq-event dev. | |
188 | * @edev : the devfreq-event device | |
189 | * | |
190 | * Note that this function stop all operations of devfreq-event dev and reset | |
191 | * the current event data to make the devfreq-event device into initial state. | |
192 | */ | |
193 | int devfreq_event_reset_event(struct devfreq_event_dev *edev) | |
194 | { | |
195 | int ret = 0; | |
196 | ||
197 | if (!edev || !edev->desc) | |
198 | return -EINVAL; | |
199 | ||
200 | if (!devfreq_event_is_enabled(edev)) | |
201 | return -EPERM; | |
202 | ||
203 | mutex_lock(&edev->lock); | |
204 | if (edev->desc->ops && edev->desc->ops->reset) | |
205 | ret = edev->desc->ops->reset(edev); | |
206 | mutex_unlock(&edev->lock); | |
207 | ||
208 | return ret; | |
209 | } | |
210 | EXPORT_SYMBOL_GPL(devfreq_event_reset_event); | |
211 | ||
212 | /** | |
213 | * devfreq_event_get_edev_by_phandle() - Get the devfreq-event dev from | |
214 | * devicetree. | |
215 | * @dev : the pointer to the given device | |
216 | * @index : the index into list of devfreq-event device | |
217 | * | |
218 | * Note that this function return the pointer of devfreq-event device. | |
219 | */ | |
220 | struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(struct device *dev, | |
221 | int index) | |
222 | { | |
223 | struct device_node *node; | |
224 | struct devfreq_event_dev *edev; | |
225 | ||
df678ff7 | 226 | if (!dev->of_node) |
f262f28c | 227 | return ERR_PTR(-EINVAL); |
f262f28c CC |
228 | |
229 | node = of_parse_phandle(dev->of_node, "devfreq-events", index); | |
df678ff7 | 230 | if (!node) |
f262f28c | 231 | return ERR_PTR(-ENODEV); |
f262f28c CC |
232 | |
233 | mutex_lock(&devfreq_event_list_lock); | |
19cf91d0 CC |
234 | list_for_each_entry(edev, &devfreq_event_list, node) { |
235 | if (edev->dev.parent && edev->dev.parent->of_node == node) | |
236 | goto out; | |
237 | } | |
238 | ||
f262f28c | 239 | list_for_each_entry(edev, &devfreq_event_list, node) { |
0d00a239 | 240 | if (of_node_name_eq(node, edev->desc->name)) |
f262f28c CC |
241 | goto out; |
242 | } | |
243 | edev = NULL; | |
244 | out: | |
245 | mutex_unlock(&devfreq_event_list_lock); | |
246 | ||
247 | if (!edev) { | |
f262f28c CC |
248 | of_node_put(node); |
249 | return ERR_PTR(-ENODEV); | |
250 | } | |
251 | ||
252 | of_node_put(node); | |
253 | ||
254 | return edev; | |
255 | } | |
256 | EXPORT_SYMBOL_GPL(devfreq_event_get_edev_by_phandle); | |
257 | ||
258 | /** | |
259 | * devfreq_event_get_edev_count() - Get the count of devfreq-event dev | |
260 | * @dev : the pointer to the given device | |
261 | * | |
262 | * Note that this function return the count of devfreq-event devices. | |
263 | */ | |
264 | int devfreq_event_get_edev_count(struct device *dev) | |
265 | { | |
266 | int count; | |
267 | ||
268 | if (!dev->of_node) { | |
269 | dev_err(dev, "device does not have a device node entry\n"); | |
270 | return -EINVAL; | |
271 | } | |
272 | ||
273 | count = of_property_count_elems_of_size(dev->of_node, "devfreq-events", | |
274 | sizeof(u32)); | |
e54916c6 | 275 | if (count < 0) { |
f262f28c | 276 | dev_err(dev, |
e8305d40 RH |
277 | "failed to get the count of devfreq-event in %pOF node\n", |
278 | dev->of_node); | |
f262f28c CC |
279 | return count; |
280 | } | |
281 | ||
282 | return count; | |
283 | } | |
284 | EXPORT_SYMBOL_GPL(devfreq_event_get_edev_count); | |
285 | ||
286 | static void devfreq_event_release_edev(struct device *dev) | |
287 | { | |
288 | struct devfreq_event_dev *edev = to_devfreq_event(dev); | |
289 | ||
290 | kfree(edev); | |
291 | } | |
292 | ||
293 | /** | |
294 | * devfreq_event_add_edev() - Add new devfreq-event device. | |
295 | * @dev : the device owning the devfreq-event device being created | |
296 | * @desc : the devfreq-event device's decriptor which include essential | |
297 | * data for devfreq-event device. | |
298 | * | |
299 | * Note that this function add new devfreq-event device to devfreq-event class | |
300 | * list and register the device of the devfreq-event device. | |
301 | */ | |
302 | struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev, | |
303 | struct devfreq_event_desc *desc) | |
304 | { | |
305 | struct devfreq_event_dev *edev; | |
775fa8c3 | 306 | static atomic_t event_no = ATOMIC_INIT(-1); |
f262f28c CC |
307 | int ret; |
308 | ||
309 | if (!dev || !desc) | |
310 | return ERR_PTR(-EINVAL); | |
311 | ||
312 | if (!desc->name || !desc->ops) | |
313 | return ERR_PTR(-EINVAL); | |
314 | ||
315 | if (!desc->ops->set_event || !desc->ops->get_event) | |
316 | return ERR_PTR(-EINVAL); | |
317 | ||
318 | edev = kzalloc(sizeof(struct devfreq_event_dev), GFP_KERNEL); | |
319 | if (!edev) | |
320 | return ERR_PTR(-ENOMEM); | |
321 | ||
322 | mutex_init(&edev->lock); | |
323 | edev->desc = desc; | |
324 | edev->enable_count = 0; | |
325 | edev->dev.parent = dev; | |
326 | edev->dev.class = devfreq_event_class; | |
327 | edev->dev.release = devfreq_event_release_edev; | |
328 | ||
775fa8c3 | 329 | dev_set_name(&edev->dev, "event%d", atomic_inc_return(&event_no)); |
f262f28c CC |
330 | ret = device_register(&edev->dev); |
331 | if (ret < 0) { | |
332 | put_device(&edev->dev); | |
333 | return ERR_PTR(ret); | |
334 | } | |
335 | dev_set_drvdata(&edev->dev, edev); | |
336 | ||
337 | INIT_LIST_HEAD(&edev->node); | |
338 | ||
339 | mutex_lock(&devfreq_event_list_lock); | |
340 | list_add(&edev->node, &devfreq_event_list); | |
341 | mutex_unlock(&devfreq_event_list_lock); | |
342 | ||
343 | return edev; | |
344 | } | |
345 | EXPORT_SYMBOL_GPL(devfreq_event_add_edev); | |
346 | ||
347 | /** | |
348 | * devfreq_event_remove_edev() - Remove the devfreq-event device registered. | |
349 | * @dev : the devfreq-event device | |
350 | * | |
351 | * Note that this function remove the registered devfreq-event device. | |
352 | */ | |
353 | int devfreq_event_remove_edev(struct devfreq_event_dev *edev) | |
354 | { | |
355 | if (!edev) | |
356 | return -EINVAL; | |
357 | ||
358 | WARN_ON(edev->enable_count); | |
359 | ||
360 | mutex_lock(&devfreq_event_list_lock); | |
361 | list_del(&edev->node); | |
362 | mutex_unlock(&devfreq_event_list_lock); | |
363 | ||
364 | device_unregister(&edev->dev); | |
365 | ||
366 | return 0; | |
367 | } | |
368 | EXPORT_SYMBOL_GPL(devfreq_event_remove_edev); | |
369 | ||
370 | static int devm_devfreq_event_match(struct device *dev, void *res, void *data) | |
371 | { | |
372 | struct devfreq_event_dev **r = res; | |
373 | ||
374 | if (WARN_ON(!r || !*r)) | |
375 | return 0; | |
376 | ||
377 | return *r == data; | |
378 | } | |
379 | ||
380 | static void devm_devfreq_event_release(struct device *dev, void *res) | |
381 | { | |
382 | devfreq_event_remove_edev(*(struct devfreq_event_dev **)res); | |
383 | } | |
384 | ||
385 | /** | |
386 | * devm_devfreq_event_add_edev() - Resource-managed devfreq_event_add_edev() | |
387 | * @dev : the device owning the devfreq-event device being created | |
388 | * @desc : the devfreq-event device's decriptor which include essential | |
389 | * data for devfreq-event device. | |
390 | * | |
391 | * Note that this function manages automatically the memory of devfreq-event | |
392 | * device using device resource management and simplify the free operation | |
393 | * for memory of devfreq-event device. | |
394 | */ | |
395 | struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev, | |
396 | struct devfreq_event_desc *desc) | |
397 | { | |
398 | struct devfreq_event_dev **ptr, *edev; | |
399 | ||
e54916c6 CC |
400 | ptr = devres_alloc(devm_devfreq_event_release, sizeof(*ptr), |
401 | GFP_KERNEL); | |
f262f28c CC |
402 | if (!ptr) |
403 | return ERR_PTR(-ENOMEM); | |
404 | ||
405 | edev = devfreq_event_add_edev(dev, desc); | |
406 | if (IS_ERR(edev)) { | |
407 | devres_free(ptr); | |
408 | return ERR_PTR(-ENOMEM); | |
409 | } | |
410 | ||
411 | *ptr = edev; | |
412 | devres_add(dev, ptr); | |
413 | ||
414 | return edev; | |
415 | } | |
416 | EXPORT_SYMBOL_GPL(devm_devfreq_event_add_edev); | |
417 | ||
418 | /** | |
419 | * devm_devfreq_event_remove_edev()- Resource-managed devfreq_event_remove_edev() | |
420 | * @dev : the device owning the devfreq-event device being created | |
421 | * @edev : the devfreq-event device | |
422 | * | |
423 | * Note that this function manages automatically the memory of devfreq-event | |
424 | * device using device resource management. | |
425 | */ | |
426 | void devm_devfreq_event_remove_edev(struct device *dev, | |
427 | struct devfreq_event_dev *edev) | |
428 | { | |
429 | WARN_ON(devres_release(dev, devm_devfreq_event_release, | |
430 | devm_devfreq_event_match, edev)); | |
431 | } | |
432 | EXPORT_SYMBOL_GPL(devm_devfreq_event_remove_edev); | |
433 | ||
434 | /* | |
435 | * Device attributes for devfreq-event class. | |
436 | */ | |
437 | static ssize_t name_show(struct device *dev, struct device_attribute *attr, | |
438 | char *buf) | |
439 | { | |
440 | struct devfreq_event_dev *edev = to_devfreq_event(dev); | |
441 | ||
442 | if (!edev || !edev->desc) | |
443 | return -EINVAL; | |
444 | ||
445 | return sprintf(buf, "%s\n", edev->desc->name); | |
446 | } | |
447 | static DEVICE_ATTR_RO(name); | |
448 | ||
449 | static ssize_t enable_count_show(struct device *dev, | |
450 | struct device_attribute *attr, char *buf) | |
451 | { | |
452 | struct devfreq_event_dev *edev = to_devfreq_event(dev); | |
453 | ||
454 | if (!edev || !edev->desc) | |
455 | return -EINVAL; | |
456 | ||
457 | return sprintf(buf, "%d\n", edev->enable_count); | |
458 | } | |
459 | static DEVICE_ATTR_RO(enable_count); | |
460 | ||
461 | static struct attribute *devfreq_event_attrs[] = { | |
462 | &dev_attr_name.attr, | |
463 | &dev_attr_enable_count.attr, | |
464 | NULL, | |
465 | }; | |
466 | ATTRIBUTE_GROUPS(devfreq_event); | |
467 | ||
468 | static int __init devfreq_event_init(void) | |
469 | { | |
470 | devfreq_event_class = class_create(THIS_MODULE, "devfreq-event"); | |
471 | if (IS_ERR(devfreq_event_class)) { | |
472 | pr_err("%s: couldn't create class\n", __FILE__); | |
473 | return PTR_ERR(devfreq_event_class); | |
474 | } | |
475 | ||
476 | devfreq_event_class->dev_groups = devfreq_event_groups; | |
477 | ||
478 | return 0; | |
479 | } | |
480 | subsys_initcall(devfreq_event_init); |