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f262f28c CC |
1 | /* |
2 | * devfreq-event: a framework to provide raw data and events of devfreq devices | |
3 | * | |
4 | * Copyright (C) 2015 Samsung Electronics | |
5 | * Author: Chanwoo Choi <cw00.choi@samsung.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * This driver is based on drivers/devfreq/devfreq.c. | |
12 | */ | |
13 | ||
14 | #include <linux/devfreq-event.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/list.h> | |
21 | #include <linux/of.h> | |
22 | ||
23 | static struct class *devfreq_event_class; | |
24 | ||
25 | /* The list of all devfreq event list */ | |
26 | static LIST_HEAD(devfreq_event_list); | |
27 | static DEFINE_MUTEX(devfreq_event_list_lock); | |
28 | ||
29 | #define to_devfreq_event(DEV) container_of(DEV, struct devfreq_event_dev, dev) | |
30 | ||
31 | /** | |
32 | * devfreq_event_enable_edev() - Enable the devfreq-event dev and increase | |
33 | * the enable_count of devfreq-event dev. | |
34 | * @edev : the devfreq-event device | |
35 | * | |
36 | * Note that this function increase the enable_count and enable the | |
37 | * devfreq-event device. The devfreq-event device should be enabled before | |
38 | * using it by devfreq device. | |
39 | */ | |
40 | int devfreq_event_enable_edev(struct devfreq_event_dev *edev) | |
41 | { | |
42 | int ret = 0; | |
43 | ||
44 | if (!edev || !edev->desc) | |
45 | return -EINVAL; | |
46 | ||
47 | mutex_lock(&edev->lock); | |
48 | if (edev->desc->ops && edev->desc->ops->enable | |
49 | && edev->enable_count == 0) { | |
50 | ret = edev->desc->ops->enable(edev); | |
51 | if (ret < 0) | |
52 | goto err; | |
53 | } | |
54 | edev->enable_count++; | |
55 | err: | |
56 | mutex_unlock(&edev->lock); | |
57 | ||
58 | return ret; | |
59 | } | |
60 | EXPORT_SYMBOL_GPL(devfreq_event_enable_edev); | |
61 | ||
62 | /** | |
63 | * devfreq_event_disable_edev() - Disable the devfreq-event dev and decrease | |
64 | * the enable_count of the devfreq-event dev. | |
65 | * @edev : the devfreq-event device | |
66 | * | |
67 | * Note that this function decrease the enable_count and disable the | |
68 | * devfreq-event device. After the devfreq-event device is disabled, | |
69 | * devfreq device can't use the devfreq-event device for get/set/reset | |
70 | * operations. | |
71 | */ | |
72 | int devfreq_event_disable_edev(struct devfreq_event_dev *edev) | |
73 | { | |
74 | int ret = 0; | |
75 | ||
76 | if (!edev || !edev->desc) | |
77 | return -EINVAL; | |
78 | ||
79 | mutex_lock(&edev->lock); | |
80 | if (edev->enable_count <= 0) { | |
81 | dev_warn(&edev->dev, "unbalanced enable_count\n"); | |
82 | ret = -EIO; | |
83 | goto err; | |
84 | } | |
85 | ||
86 | if (edev->desc->ops && edev->desc->ops->disable | |
87 | && edev->enable_count == 1) { | |
88 | ret = edev->desc->ops->disable(edev); | |
89 | if (ret < 0) | |
90 | goto err; | |
91 | } | |
92 | edev->enable_count--; | |
93 | err: | |
94 | mutex_unlock(&edev->lock); | |
95 | ||
96 | return ret; | |
97 | } | |
98 | EXPORT_SYMBOL_GPL(devfreq_event_disable_edev); | |
99 | ||
100 | /** | |
101 | * devfreq_event_is_enabled() - Check whether devfreq-event dev is enabled or | |
102 | * not. | |
103 | * @edev : the devfreq-event device | |
104 | * | |
105 | * Note that this function check whether devfreq-event dev is enabled or not. | |
106 | * If return true, the devfreq-event dev is enabeld. If return false, the | |
107 | * devfreq-event dev is disabled. | |
108 | */ | |
109 | bool devfreq_event_is_enabled(struct devfreq_event_dev *edev) | |
110 | { | |
111 | bool enabled = false; | |
112 | ||
113 | if (!edev || !edev->desc) | |
114 | return enabled; | |
115 | ||
116 | mutex_lock(&edev->lock); | |
117 | ||
118 | if (edev->enable_count > 0) | |
119 | enabled = true; | |
120 | ||
121 | mutex_unlock(&edev->lock); | |
122 | ||
123 | return enabled; | |
124 | } | |
125 | EXPORT_SYMBOL_GPL(devfreq_event_is_enabled); | |
126 | ||
127 | /** | |
128 | * devfreq_event_set_event() - Set event to devfreq-event dev to start. | |
129 | * @edev : the devfreq-event device | |
130 | * | |
131 | * Note that this function set the event to the devfreq-event device to start | |
132 | * for getting the event data which could be various event type. | |
133 | */ | |
134 | int devfreq_event_set_event(struct devfreq_event_dev *edev) | |
135 | { | |
136 | int ret; | |
137 | ||
138 | if (!edev || !edev->desc) | |
139 | return -EINVAL; | |
140 | ||
141 | if (!edev->desc->ops || !edev->desc->ops->set_event) | |
142 | return -EINVAL; | |
143 | ||
144 | if (!devfreq_event_is_enabled(edev)) | |
145 | return -EPERM; | |
146 | ||
147 | mutex_lock(&edev->lock); | |
148 | ret = edev->desc->ops->set_event(edev); | |
149 | mutex_unlock(&edev->lock); | |
150 | ||
151 | return ret; | |
152 | } | |
153 | EXPORT_SYMBOL_GPL(devfreq_event_set_event); | |
154 | ||
155 | /** | |
156 | * devfreq_event_get_event() - Get {load|total}_count from devfreq-event dev. | |
157 | * @edev : the devfreq-event device | |
158 | * @edata : the calculated data of devfreq-event device | |
159 | * | |
160 | * Note that this function get the calculated event data from devfreq-event dev | |
161 | * after stoping the progress of whole sequence of devfreq-event dev. | |
162 | */ | |
163 | int devfreq_event_get_event(struct devfreq_event_dev *edev, | |
164 | struct devfreq_event_data *edata) | |
165 | { | |
166 | int ret; | |
167 | ||
168 | if (!edev || !edev->desc) | |
169 | return -EINVAL; | |
170 | ||
171 | if (!edev->desc->ops || !edev->desc->ops->get_event) | |
172 | return -EINVAL; | |
173 | ||
174 | if (!devfreq_event_is_enabled(edev)) | |
175 | return -EINVAL; | |
176 | ||
177 | edata->total_count = edata->load_count = 0; | |
178 | ||
179 | mutex_lock(&edev->lock); | |
180 | ret = edev->desc->ops->get_event(edev, edata); | |
181 | if (ret < 0) | |
182 | edata->total_count = edata->load_count = 0; | |
183 | mutex_unlock(&edev->lock); | |
184 | ||
185 | return ret; | |
186 | } | |
187 | EXPORT_SYMBOL_GPL(devfreq_event_get_event); | |
188 | ||
189 | /** | |
190 | * devfreq_event_reset_event() - Reset all opeations of devfreq-event dev. | |
191 | * @edev : the devfreq-event device | |
192 | * | |
193 | * Note that this function stop all operations of devfreq-event dev and reset | |
194 | * the current event data to make the devfreq-event device into initial state. | |
195 | */ | |
196 | int devfreq_event_reset_event(struct devfreq_event_dev *edev) | |
197 | { | |
198 | int ret = 0; | |
199 | ||
200 | if (!edev || !edev->desc) | |
201 | return -EINVAL; | |
202 | ||
203 | if (!devfreq_event_is_enabled(edev)) | |
204 | return -EPERM; | |
205 | ||
206 | mutex_lock(&edev->lock); | |
207 | if (edev->desc->ops && edev->desc->ops->reset) | |
208 | ret = edev->desc->ops->reset(edev); | |
209 | mutex_unlock(&edev->lock); | |
210 | ||
211 | return ret; | |
212 | } | |
213 | EXPORT_SYMBOL_GPL(devfreq_event_reset_event); | |
214 | ||
215 | /** | |
216 | * devfreq_event_get_edev_by_phandle() - Get the devfreq-event dev from | |
217 | * devicetree. | |
218 | * @dev : the pointer to the given device | |
219 | * @index : the index into list of devfreq-event device | |
220 | * | |
221 | * Note that this function return the pointer of devfreq-event device. | |
222 | */ | |
223 | struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(struct device *dev, | |
224 | int index) | |
225 | { | |
226 | struct device_node *node; | |
227 | struct devfreq_event_dev *edev; | |
228 | ||
229 | if (!dev->of_node) { | |
230 | dev_err(dev, "device does not have a device node entry\n"); | |
231 | return ERR_PTR(-EINVAL); | |
232 | } | |
233 | ||
234 | node = of_parse_phandle(dev->of_node, "devfreq-events", index); | |
235 | if (!node) { | |
236 | dev_err(dev, "failed to get phandle in %s node\n", | |
237 | dev->of_node->full_name); | |
238 | return ERR_PTR(-ENODEV); | |
239 | } | |
240 | ||
241 | mutex_lock(&devfreq_event_list_lock); | |
242 | list_for_each_entry(edev, &devfreq_event_list, node) { | |
243 | if (!strcmp(edev->desc->name, node->name)) | |
244 | goto out; | |
245 | } | |
246 | edev = NULL; | |
247 | out: | |
248 | mutex_unlock(&devfreq_event_list_lock); | |
249 | ||
250 | if (!edev) { | |
251 | dev_err(dev, "unable to get devfreq-event device : %s\n", | |
252 | node->name); | |
253 | of_node_put(node); | |
254 | return ERR_PTR(-ENODEV); | |
255 | } | |
256 | ||
257 | of_node_put(node); | |
258 | ||
259 | return edev; | |
260 | } | |
261 | EXPORT_SYMBOL_GPL(devfreq_event_get_edev_by_phandle); | |
262 | ||
263 | /** | |
264 | * devfreq_event_get_edev_count() - Get the count of devfreq-event dev | |
265 | * @dev : the pointer to the given device | |
266 | * | |
267 | * Note that this function return the count of devfreq-event devices. | |
268 | */ | |
269 | int devfreq_event_get_edev_count(struct device *dev) | |
270 | { | |
271 | int count; | |
272 | ||
273 | if (!dev->of_node) { | |
274 | dev_err(dev, "device does not have a device node entry\n"); | |
275 | return -EINVAL; | |
276 | } | |
277 | ||
278 | count = of_property_count_elems_of_size(dev->of_node, "devfreq-events", | |
279 | sizeof(u32)); | |
280 | if (count < 0 ) { | |
281 | dev_err(dev, | |
282 | "failed to get the count of devfreq-event in %s node\n", | |
283 | dev->of_node->full_name); | |
284 | return count; | |
285 | } | |
286 | ||
287 | return count; | |
288 | } | |
289 | EXPORT_SYMBOL_GPL(devfreq_event_get_edev_count); | |
290 | ||
291 | static void devfreq_event_release_edev(struct device *dev) | |
292 | { | |
293 | struct devfreq_event_dev *edev = to_devfreq_event(dev); | |
294 | ||
295 | kfree(edev); | |
296 | } | |
297 | ||
298 | /** | |
299 | * devfreq_event_add_edev() - Add new devfreq-event device. | |
300 | * @dev : the device owning the devfreq-event device being created | |
301 | * @desc : the devfreq-event device's decriptor which include essential | |
302 | * data for devfreq-event device. | |
303 | * | |
304 | * Note that this function add new devfreq-event device to devfreq-event class | |
305 | * list and register the device of the devfreq-event device. | |
306 | */ | |
307 | struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev, | |
308 | struct devfreq_event_desc *desc) | |
309 | { | |
310 | struct devfreq_event_dev *edev; | |
311 | static atomic_t event_no = ATOMIC_INIT(0); | |
312 | int ret; | |
313 | ||
314 | if (!dev || !desc) | |
315 | return ERR_PTR(-EINVAL); | |
316 | ||
317 | if (!desc->name || !desc->ops) | |
318 | return ERR_PTR(-EINVAL); | |
319 | ||
320 | if (!desc->ops->set_event || !desc->ops->get_event) | |
321 | return ERR_PTR(-EINVAL); | |
322 | ||
323 | edev = kzalloc(sizeof(struct devfreq_event_dev), GFP_KERNEL); | |
324 | if (!edev) | |
325 | return ERR_PTR(-ENOMEM); | |
326 | ||
327 | mutex_init(&edev->lock); | |
328 | edev->desc = desc; | |
329 | edev->enable_count = 0; | |
330 | edev->dev.parent = dev; | |
331 | edev->dev.class = devfreq_event_class; | |
332 | edev->dev.release = devfreq_event_release_edev; | |
333 | ||
334 | dev_set_name(&edev->dev, "event.%d", atomic_inc_return(&event_no) - 1); | |
335 | ret = device_register(&edev->dev); | |
336 | if (ret < 0) { | |
337 | put_device(&edev->dev); | |
338 | return ERR_PTR(ret); | |
339 | } | |
340 | dev_set_drvdata(&edev->dev, edev); | |
341 | ||
342 | INIT_LIST_HEAD(&edev->node); | |
343 | ||
344 | mutex_lock(&devfreq_event_list_lock); | |
345 | list_add(&edev->node, &devfreq_event_list); | |
346 | mutex_unlock(&devfreq_event_list_lock); | |
347 | ||
348 | return edev; | |
349 | } | |
350 | EXPORT_SYMBOL_GPL(devfreq_event_add_edev); | |
351 | ||
352 | /** | |
353 | * devfreq_event_remove_edev() - Remove the devfreq-event device registered. | |
354 | * @dev : the devfreq-event device | |
355 | * | |
356 | * Note that this function remove the registered devfreq-event device. | |
357 | */ | |
358 | int devfreq_event_remove_edev(struct devfreq_event_dev *edev) | |
359 | { | |
360 | if (!edev) | |
361 | return -EINVAL; | |
362 | ||
363 | WARN_ON(edev->enable_count); | |
364 | ||
365 | mutex_lock(&devfreq_event_list_lock); | |
366 | list_del(&edev->node); | |
367 | mutex_unlock(&devfreq_event_list_lock); | |
368 | ||
369 | device_unregister(&edev->dev); | |
370 | ||
371 | return 0; | |
372 | } | |
373 | EXPORT_SYMBOL_GPL(devfreq_event_remove_edev); | |
374 | ||
375 | static int devm_devfreq_event_match(struct device *dev, void *res, void *data) | |
376 | { | |
377 | struct devfreq_event_dev **r = res; | |
378 | ||
379 | if (WARN_ON(!r || !*r)) | |
380 | return 0; | |
381 | ||
382 | return *r == data; | |
383 | } | |
384 | ||
385 | static void devm_devfreq_event_release(struct device *dev, void *res) | |
386 | { | |
387 | devfreq_event_remove_edev(*(struct devfreq_event_dev **)res); | |
388 | } | |
389 | ||
390 | /** | |
391 | * devm_devfreq_event_add_edev() - Resource-managed devfreq_event_add_edev() | |
392 | * @dev : the device owning the devfreq-event device being created | |
393 | * @desc : the devfreq-event device's decriptor which include essential | |
394 | * data for devfreq-event device. | |
395 | * | |
396 | * Note that this function manages automatically the memory of devfreq-event | |
397 | * device using device resource management and simplify the free operation | |
398 | * for memory of devfreq-event device. | |
399 | */ | |
400 | struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev, | |
401 | struct devfreq_event_desc *desc) | |
402 | { | |
403 | struct devfreq_event_dev **ptr, *edev; | |
404 | ||
405 | ptr = devres_alloc(devm_devfreq_event_release, sizeof(*ptr), GFP_KERNEL); | |
406 | if (!ptr) | |
407 | return ERR_PTR(-ENOMEM); | |
408 | ||
409 | edev = devfreq_event_add_edev(dev, desc); | |
410 | if (IS_ERR(edev)) { | |
411 | devres_free(ptr); | |
412 | return ERR_PTR(-ENOMEM); | |
413 | } | |
414 | ||
415 | *ptr = edev; | |
416 | devres_add(dev, ptr); | |
417 | ||
418 | return edev; | |
419 | } | |
420 | EXPORT_SYMBOL_GPL(devm_devfreq_event_add_edev); | |
421 | ||
422 | /** | |
423 | * devm_devfreq_event_remove_edev()- Resource-managed devfreq_event_remove_edev() | |
424 | * @dev : the device owning the devfreq-event device being created | |
425 | * @edev : the devfreq-event device | |
426 | * | |
427 | * Note that this function manages automatically the memory of devfreq-event | |
428 | * device using device resource management. | |
429 | */ | |
430 | void devm_devfreq_event_remove_edev(struct device *dev, | |
431 | struct devfreq_event_dev *edev) | |
432 | { | |
433 | WARN_ON(devres_release(dev, devm_devfreq_event_release, | |
434 | devm_devfreq_event_match, edev)); | |
435 | } | |
436 | EXPORT_SYMBOL_GPL(devm_devfreq_event_remove_edev); | |
437 | ||
438 | /* | |
439 | * Device attributes for devfreq-event class. | |
440 | */ | |
441 | static ssize_t name_show(struct device *dev, struct device_attribute *attr, | |
442 | char *buf) | |
443 | { | |
444 | struct devfreq_event_dev *edev = to_devfreq_event(dev); | |
445 | ||
446 | if (!edev || !edev->desc) | |
447 | return -EINVAL; | |
448 | ||
449 | return sprintf(buf, "%s\n", edev->desc->name); | |
450 | } | |
451 | static DEVICE_ATTR_RO(name); | |
452 | ||
453 | static ssize_t enable_count_show(struct device *dev, | |
454 | struct device_attribute *attr, char *buf) | |
455 | { | |
456 | struct devfreq_event_dev *edev = to_devfreq_event(dev); | |
457 | ||
458 | if (!edev || !edev->desc) | |
459 | return -EINVAL; | |
460 | ||
461 | return sprintf(buf, "%d\n", edev->enable_count); | |
462 | } | |
463 | static DEVICE_ATTR_RO(enable_count); | |
464 | ||
465 | static struct attribute *devfreq_event_attrs[] = { | |
466 | &dev_attr_name.attr, | |
467 | &dev_attr_enable_count.attr, | |
468 | NULL, | |
469 | }; | |
470 | ATTRIBUTE_GROUPS(devfreq_event); | |
471 | ||
472 | static int __init devfreq_event_init(void) | |
473 | { | |
474 | devfreq_event_class = class_create(THIS_MODULE, "devfreq-event"); | |
475 | if (IS_ERR(devfreq_event_class)) { | |
476 | pr_err("%s: couldn't create class\n", __FILE__); | |
477 | return PTR_ERR(devfreq_event_class); | |
478 | } | |
479 | ||
480 | devfreq_event_class->dev_groups = devfreq_event_groups; | |
481 | ||
482 | return 0; | |
483 | } | |
484 | subsys_initcall(devfreq_event_init); | |
485 | ||
486 | static void __exit devfreq_event_exit(void) | |
487 | { | |
488 | class_destroy(devfreq_event_class); | |
489 | } | |
490 | module_exit(devfreq_event_exit); | |
491 | ||
492 | MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>"); | |
493 | MODULE_DESCRIPTION("DEVFREQ-Event class support"); | |
494 | MODULE_LICENSE("GPL"); |