1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * LED Flash class interface
4 *
5 * Copyright (C) 2015 Samsung Electronics Co., Ltd.
6 * Author: Jacek Anaszewski <j.anaszewski@samsung.com>
7 */
8
9 #include <linux/device.h>
10 #include <linux/init.h>
11 #include <linux/led-class-flash.h>
12 #include <linux/leds.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include "leds.h"
16
17 #define has_flash_op(fled_cdev, op) \
18 (fled_cdev && fled_cdev->ops->op)
19
20 #define call_flash_op(fled_cdev, op, args...) \
21 ((has_flash_op(fled_cdev, op)) ? \
22 (fled_cdev->ops->op(fled_cdev, args)) : \
23 -EINVAL)
24
25 static const char * const led_flash_fault_names[] = {
26 "led-over-voltage",
27 "flash-timeout-exceeded",
28 "controller-over-temperature",
29 "controller-short-circuit",
30 "led-power-supply-over-current",
31 "indicator-led-fault",
32 "led-under-voltage",
33 "controller-under-voltage",
34 "led-over-temperature",
35 };
36
flash_brightness_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)37 static ssize_t flash_brightness_store(struct device *dev,
38 struct device_attribute *attr, const char *buf, size_t size)
39 {
40 struct led_classdev *led_cdev = dev_get_drvdata(dev);
41 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
42 unsigned long state;
43 ssize_t ret;
44
45 mutex_lock(&led_cdev->led_access);
46
47 if (led_sysfs_is_disabled(led_cdev)) {
48 ret = -EBUSY;
49 goto unlock;
50 }
51
52 ret = kstrtoul(buf, 10, &state);
53 if (ret)
54 goto unlock;
55
56 ret = led_set_flash_brightness(fled_cdev, state);
57 if (ret < 0)
58 goto unlock;
59
60 ret = size;
61 unlock:
62 mutex_unlock(&led_cdev->led_access);
63 return ret;
64 }
65
flash_brightness_show(struct device * dev,struct device_attribute * attr,char * buf)66 static ssize_t flash_brightness_show(struct device *dev,
67 struct device_attribute *attr, char *buf)
68 {
69 struct led_classdev *led_cdev = dev_get_drvdata(dev);
70 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
71
72 /* no lock needed for this */
73 led_update_flash_brightness(fled_cdev);
74
75 return sprintf(buf, "%u\n", fled_cdev->brightness.val);
76 }
77 static DEVICE_ATTR_RW(flash_brightness);
78
max_flash_brightness_show(struct device * dev,struct device_attribute * attr,char * buf)79 static ssize_t max_flash_brightness_show(struct device *dev,
80 struct device_attribute *attr, char *buf)
81 {
82 struct led_classdev *led_cdev = dev_get_drvdata(dev);
83 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
84
85 return sprintf(buf, "%u\n", fled_cdev->brightness.max);
86 }
87 static DEVICE_ATTR_RO(max_flash_brightness);
88
flash_strobe_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)89 static ssize_t flash_strobe_store(struct device *dev,
90 struct device_attribute *attr, const char *buf, size_t size)
91 {
92 struct led_classdev *led_cdev = dev_get_drvdata(dev);
93 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
94 unsigned long state;
95 ssize_t ret = -EINVAL;
96
97 mutex_lock(&led_cdev->led_access);
98
99 if (led_sysfs_is_disabled(led_cdev)) {
100 ret = -EBUSY;
101 goto unlock;
102 }
103
104 ret = kstrtoul(buf, 10, &state);
105 if (ret)
106 goto unlock;
107
108 if (state > 1) {
109 ret = -EINVAL;
110 goto unlock;
111 }
112
113 ret = led_set_flash_strobe(fled_cdev, state);
114 if (ret < 0)
115 goto unlock;
116 ret = size;
117 unlock:
118 mutex_unlock(&led_cdev->led_access);
119 return ret;
120 }
121
flash_strobe_show(struct device * dev,struct device_attribute * attr,char * buf)122 static ssize_t flash_strobe_show(struct device *dev,
123 struct device_attribute *attr, char *buf)
124 {
125 struct led_classdev *led_cdev = dev_get_drvdata(dev);
126 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
127 bool state;
128 int ret;
129
130 /* no lock needed for this */
131 ret = led_get_flash_strobe(fled_cdev, &state);
132 if (ret < 0)
133 return ret;
134
135 return sprintf(buf, "%u\n", state);
136 }
137 static DEVICE_ATTR_RW(flash_strobe);
138
flash_timeout_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)139 static ssize_t flash_timeout_store(struct device *dev,
140 struct device_attribute *attr, const char *buf, size_t size)
141 {
142 struct led_classdev *led_cdev = dev_get_drvdata(dev);
143 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
144 unsigned long flash_timeout;
145 ssize_t ret;
146
147 mutex_lock(&led_cdev->led_access);
148
149 if (led_sysfs_is_disabled(led_cdev)) {
150 ret = -EBUSY;
151 goto unlock;
152 }
153
154 ret = kstrtoul(buf, 10, &flash_timeout);
155 if (ret)
156 goto unlock;
157
158 ret = led_set_flash_timeout(fled_cdev, flash_timeout);
159 if (ret < 0)
160 goto unlock;
161
162 ret = size;
163 unlock:
164 mutex_unlock(&led_cdev->led_access);
165 return ret;
166 }
167
flash_timeout_show(struct device * dev,struct device_attribute * attr,char * buf)168 static ssize_t flash_timeout_show(struct device *dev,
169 struct device_attribute *attr, char *buf)
170 {
171 struct led_classdev *led_cdev = dev_get_drvdata(dev);
172 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
173
174 return sprintf(buf, "%u\n", fled_cdev->timeout.val);
175 }
176 static DEVICE_ATTR_RW(flash_timeout);
177
max_flash_timeout_show(struct device * dev,struct device_attribute * attr,char * buf)178 static ssize_t max_flash_timeout_show(struct device *dev,
179 struct device_attribute *attr, char *buf)
180 {
181 struct led_classdev *led_cdev = dev_get_drvdata(dev);
182 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
183
184 return sprintf(buf, "%u\n", fled_cdev->timeout.max);
185 }
186 static DEVICE_ATTR_RO(max_flash_timeout);
187
flash_fault_show(struct device * dev,struct device_attribute * attr,char * buf)188 static ssize_t flash_fault_show(struct device *dev,
189 struct device_attribute *attr, char *buf)
190 {
191 struct led_classdev *led_cdev = dev_get_drvdata(dev);
192 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
193 u32 fault, mask = 0x1;
194 char *pbuf = buf;
195 int i, ret, buf_len;
196
197 ret = led_get_flash_fault(fled_cdev, &fault);
198 if (ret < 0)
199 return -EINVAL;
200
201 *buf = '\0';
202
203 for (i = 0; i < LED_NUM_FLASH_FAULTS; ++i) {
204 if (fault & mask) {
205 buf_len = sprintf(pbuf, "%s ",
206 led_flash_fault_names[i]);
207 pbuf += buf_len;
208 }
209 mask <<= 1;
210 }
211
212 return sprintf(buf, "%s\n", buf);
213 }
214 static DEVICE_ATTR_RO(flash_fault);
215
216 static struct attribute *led_flash_strobe_attrs[] = {
217 &dev_attr_flash_strobe.attr,
218 NULL,
219 };
220
221 static struct attribute *led_flash_timeout_attrs[] = {
222 &dev_attr_flash_timeout.attr,
223 &dev_attr_max_flash_timeout.attr,
224 NULL,
225 };
226
227 static struct attribute *led_flash_brightness_attrs[] = {
228 &dev_attr_flash_brightness.attr,
229 &dev_attr_max_flash_brightness.attr,
230 NULL,
231 };
232
233 static struct attribute *led_flash_fault_attrs[] = {
234 &dev_attr_flash_fault.attr,
235 NULL,
236 };
237
238 static const struct attribute_group led_flash_strobe_group = {
239 .attrs = led_flash_strobe_attrs,
240 };
241
242 static const struct attribute_group led_flash_timeout_group = {
243 .attrs = led_flash_timeout_attrs,
244 };
245
246 static const struct attribute_group led_flash_brightness_group = {
247 .attrs = led_flash_brightness_attrs,
248 };
249
250 static const struct attribute_group led_flash_fault_group = {
251 .attrs = led_flash_fault_attrs,
252 };
253
led_flash_resume(struct led_classdev * led_cdev)254 static void led_flash_resume(struct led_classdev *led_cdev)
255 {
256 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
257
258 call_flash_op(fled_cdev, flash_brightness_set,
259 fled_cdev->brightness.val);
260 call_flash_op(fled_cdev, timeout_set, fled_cdev->timeout.val);
261 }
262
led_flash_init_sysfs_groups(struct led_classdev_flash * fled_cdev)263 static void led_flash_init_sysfs_groups(struct led_classdev_flash *fled_cdev)
264 {
265 struct led_classdev *led_cdev = &fled_cdev->led_cdev;
266 const struct led_flash_ops *ops = fled_cdev->ops;
267 const struct attribute_group **flash_groups = fled_cdev->sysfs_groups;
268
269 int num_sysfs_groups = 0;
270
271 flash_groups[num_sysfs_groups++] = &led_flash_strobe_group;
272
273 if (ops->flash_brightness_set)
274 flash_groups[num_sysfs_groups++] = &led_flash_brightness_group;
275
276 if (ops->timeout_set)
277 flash_groups[num_sysfs_groups++] = &led_flash_timeout_group;
278
279 if (ops->fault_get)
280 flash_groups[num_sysfs_groups++] = &led_flash_fault_group;
281
282 led_cdev->groups = flash_groups;
283 }
284
led_classdev_flash_register_ext(struct device * parent,struct led_classdev_flash * fled_cdev,struct led_init_data * init_data)285 int led_classdev_flash_register_ext(struct device *parent,
286 struct led_classdev_flash *fled_cdev,
287 struct led_init_data *init_data)
288 {
289 struct led_classdev *led_cdev;
290 const struct led_flash_ops *ops;
291 int ret;
292
293 if (!fled_cdev)
294 return -EINVAL;
295
296 led_cdev = &fled_cdev->led_cdev;
297
298 if (led_cdev->flags & LED_DEV_CAP_FLASH) {
299 if (!led_cdev->brightness_set_blocking)
300 return -EINVAL;
301
302 ops = fled_cdev->ops;
303 if (!ops || !ops->strobe_set)
304 return -EINVAL;
305
306 led_cdev->flash_resume = led_flash_resume;
307
308 /* Select the sysfs attributes to be created for the device */
309 led_flash_init_sysfs_groups(fled_cdev);
310 }
311
312 /* Register led class device */
313 ret = led_classdev_register_ext(parent, led_cdev, init_data);
314 if (ret < 0)
315 return ret;
316
317 return 0;
318 }
319 EXPORT_SYMBOL_GPL(led_classdev_flash_register_ext);
320
led_classdev_flash_unregister(struct led_classdev_flash * fled_cdev)321 void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev)
322 {
323 if (!fled_cdev)
324 return;
325
326 led_classdev_unregister(&fled_cdev->led_cdev);
327 }
328 EXPORT_SYMBOL_GPL(led_classdev_flash_unregister);
329
devm_led_classdev_flash_release(struct device * dev,void * res)330 static void devm_led_classdev_flash_release(struct device *dev, void *res)
331 {
332 led_classdev_flash_unregister(*(struct led_classdev_flash **)res);
333 }
334
devm_led_classdev_flash_register_ext(struct device * parent,struct led_classdev_flash * fled_cdev,struct led_init_data * init_data)335 int devm_led_classdev_flash_register_ext(struct device *parent,
336 struct led_classdev_flash *fled_cdev,
337 struct led_init_data *init_data)
338 {
339 struct led_classdev_flash **dr;
340 int ret;
341
342 dr = devres_alloc(devm_led_classdev_flash_release, sizeof(*dr),
343 GFP_KERNEL);
344 if (!dr)
345 return -ENOMEM;
346
347 ret = led_classdev_flash_register_ext(parent, fled_cdev, init_data);
348 if (ret) {
349 devres_free(dr);
350 return ret;
351 }
352
353 *dr = fled_cdev;
354 devres_add(parent, dr);
355
356 return 0;
357 }
358 EXPORT_SYMBOL_GPL(devm_led_classdev_flash_register_ext);
359
devm_led_classdev_flash_match(struct device * dev,void * res,void * data)360 static int devm_led_classdev_flash_match(struct device *dev,
361 void *res, void *data)
362 {
363 struct led_classdev_flash **p = res;
364
365 if (WARN_ON(!p || !*p))
366 return 0;
367
368 return *p == data;
369 }
370
devm_led_classdev_flash_unregister(struct device * dev,struct led_classdev_flash * fled_cdev)371 void devm_led_classdev_flash_unregister(struct device *dev,
372 struct led_classdev_flash *fled_cdev)
373 {
374 WARN_ON(devres_release(dev,
375 devm_led_classdev_flash_release,
376 devm_led_classdev_flash_match, fled_cdev));
377 }
378 EXPORT_SYMBOL_GPL(devm_led_classdev_flash_unregister);
379
led_clamp_align(struct led_flash_setting * s)380 static void led_clamp_align(struct led_flash_setting *s)
381 {
382 u32 v, offset;
383
384 v = s->val + s->step / 2;
385 v = clamp(v, s->min, s->max);
386 offset = v - s->min;
387 offset = s->step * (offset / s->step);
388 s->val = s->min + offset;
389 }
390
led_set_flash_timeout(struct led_classdev_flash * fled_cdev,u32 timeout)391 int led_set_flash_timeout(struct led_classdev_flash *fled_cdev, u32 timeout)
392 {
393 struct led_classdev *led_cdev = &fled_cdev->led_cdev;
394 struct led_flash_setting *s = &fled_cdev->timeout;
395
396 s->val = timeout;
397 led_clamp_align(s);
398
399 if (!(led_cdev->flags & LED_SUSPENDED))
400 return call_flash_op(fled_cdev, timeout_set, s->val);
401
402 return 0;
403 }
404 EXPORT_SYMBOL_GPL(led_set_flash_timeout);
405
led_get_flash_fault(struct led_classdev_flash * fled_cdev,u32 * fault)406 int led_get_flash_fault(struct led_classdev_flash *fled_cdev, u32 *fault)
407 {
408 return call_flash_op(fled_cdev, fault_get, fault);
409 }
410 EXPORT_SYMBOL_GPL(led_get_flash_fault);
411
led_set_flash_brightness(struct led_classdev_flash * fled_cdev,u32 brightness)412 int led_set_flash_brightness(struct led_classdev_flash *fled_cdev,
413 u32 brightness)
414 {
415 struct led_classdev *led_cdev = &fled_cdev->led_cdev;
416 struct led_flash_setting *s = &fled_cdev->brightness;
417
418 s->val = brightness;
419 led_clamp_align(s);
420
421 if (!(led_cdev->flags & LED_SUSPENDED))
422 return call_flash_op(fled_cdev, flash_brightness_set, s->val);
423
424 return 0;
425 }
426 EXPORT_SYMBOL_GPL(led_set_flash_brightness);
427
led_update_flash_brightness(struct led_classdev_flash * fled_cdev)428 int led_update_flash_brightness(struct led_classdev_flash *fled_cdev)
429 {
430 struct led_flash_setting *s = &fled_cdev->brightness;
431 u32 brightness;
432
433 if (has_flash_op(fled_cdev, flash_brightness_get)) {
434 int ret = call_flash_op(fled_cdev, flash_brightness_get,
435 &brightness);
436 if (ret < 0)
437 return ret;
438
439 s->val = brightness;
440 }
441
442 return 0;
443 }
444 EXPORT_SYMBOL_GPL(led_update_flash_brightness);
445
446 MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
447 MODULE_DESCRIPTION("LED Flash class interface");
448 MODULE_LICENSE("GPL v2");
449