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 = -EBUSY;
96
97 mutex_lock(&led_cdev->led_access);
98
99 if (led_sysfs_is_disabled(led_cdev))
100 goto unlock;
101
102 ret = kstrtoul(buf, 10, &state);
103 if (ret)
104 goto unlock;
105
106 if (state > 1) {
107 ret = -EINVAL;
108 goto unlock;
109 }
110
111 ret = led_set_flash_strobe(fled_cdev, state);
112 if (ret < 0)
113 goto unlock;
114 ret = size;
115 unlock:
116 mutex_unlock(&led_cdev->led_access);
117 return ret;
118 }
119
flash_strobe_show(struct device * dev,struct device_attribute * attr,char * buf)120 static ssize_t flash_strobe_show(struct device *dev,
121 struct device_attribute *attr, char *buf)
122 {
123 struct led_classdev *led_cdev = dev_get_drvdata(dev);
124 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
125 bool state;
126 int ret;
127
128 /* no lock needed for this */
129 ret = led_get_flash_strobe(fled_cdev, &state);
130 if (ret < 0)
131 return ret;
132
133 return sprintf(buf, "%u\n", state);
134 }
135 static DEVICE_ATTR_RW(flash_strobe);
136
flash_timeout_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)137 static ssize_t flash_timeout_store(struct device *dev,
138 struct device_attribute *attr, const char *buf, size_t size)
139 {
140 struct led_classdev *led_cdev = dev_get_drvdata(dev);
141 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
142 unsigned long flash_timeout;
143 ssize_t ret;
144
145 mutex_lock(&led_cdev->led_access);
146
147 if (led_sysfs_is_disabled(led_cdev)) {
148 ret = -EBUSY;
149 goto unlock;
150 }
151
152 ret = kstrtoul(buf, 10, &flash_timeout);
153 if (ret)
154 goto unlock;
155
156 ret = led_set_flash_timeout(fled_cdev, flash_timeout);
157 if (ret < 0)
158 goto unlock;
159
160 ret = size;
161 unlock:
162 mutex_unlock(&led_cdev->led_access);
163 return ret;
164 }
165
flash_timeout_show(struct device * dev,struct device_attribute * attr,char * buf)166 static ssize_t flash_timeout_show(struct device *dev,
167 struct device_attribute *attr, char *buf)
168 {
169 struct led_classdev *led_cdev = dev_get_drvdata(dev);
170 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
171
172 return sprintf(buf, "%u\n", fled_cdev->timeout.val);
173 }
174 static DEVICE_ATTR_RW(flash_timeout);
175
max_flash_timeout_show(struct device * dev,struct device_attribute * attr,char * buf)176 static ssize_t max_flash_timeout_show(struct device *dev,
177 struct device_attribute *attr, char *buf)
178 {
179 struct led_classdev *led_cdev = dev_get_drvdata(dev);
180 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
181
182 return sprintf(buf, "%u\n", fled_cdev->timeout.max);
183 }
184 static DEVICE_ATTR_RO(max_flash_timeout);
185
flash_fault_show(struct device * dev,struct device_attribute * attr,char * buf)186 static ssize_t flash_fault_show(struct device *dev,
187 struct device_attribute *attr, char *buf)
188 {
189 struct led_classdev *led_cdev = dev_get_drvdata(dev);
190 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
191 u32 fault, mask = 0x1;
192 char *pbuf = buf;
193 int i, ret, buf_len;
194
195 ret = led_get_flash_fault(fled_cdev, &fault);
196 if (ret < 0)
197 return -EINVAL;
198
199 *buf = '\0';
200
201 for (i = 0; i < LED_NUM_FLASH_FAULTS; ++i) {
202 if (fault & mask) {
203 buf_len = sprintf(pbuf, "%s ",
204 led_flash_fault_names[i]);
205 pbuf += buf_len;
206 }
207 mask <<= 1;
208 }
209
210 return strlen(strcat(buf, "\n"));
211 }
212 static DEVICE_ATTR_RO(flash_fault);
213
214 static struct attribute *led_flash_strobe_attrs[] = {
215 &dev_attr_flash_strobe.attr,
216 NULL,
217 };
218
219 static struct attribute *led_flash_timeout_attrs[] = {
220 &dev_attr_flash_timeout.attr,
221 &dev_attr_max_flash_timeout.attr,
222 NULL,
223 };
224
225 static struct attribute *led_flash_brightness_attrs[] = {
226 &dev_attr_flash_brightness.attr,
227 &dev_attr_max_flash_brightness.attr,
228 NULL,
229 };
230
231 static struct attribute *led_flash_fault_attrs[] = {
232 &dev_attr_flash_fault.attr,
233 NULL,
234 };
235
236 static const struct attribute_group led_flash_strobe_group = {
237 .attrs = led_flash_strobe_attrs,
238 };
239
240 static const struct attribute_group led_flash_timeout_group = {
241 .attrs = led_flash_timeout_attrs,
242 };
243
244 static const struct attribute_group led_flash_brightness_group = {
245 .attrs = led_flash_brightness_attrs,
246 };
247
248 static const struct attribute_group led_flash_fault_group = {
249 .attrs = led_flash_fault_attrs,
250 };
251
led_flash_resume(struct led_classdev * led_cdev)252 static void led_flash_resume(struct led_classdev *led_cdev)
253 {
254 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
255
256 call_flash_op(fled_cdev, flash_brightness_set,
257 fled_cdev->brightness.val);
258 call_flash_op(fled_cdev, timeout_set, fled_cdev->timeout.val);
259 }
260
led_flash_init_sysfs_groups(struct led_classdev_flash * fled_cdev)261 static void led_flash_init_sysfs_groups(struct led_classdev_flash *fled_cdev)
262 {
263 struct led_classdev *led_cdev = &fled_cdev->led_cdev;
264 const struct led_flash_ops *ops = fled_cdev->ops;
265 const struct attribute_group **flash_groups = fled_cdev->sysfs_groups;
266
267 int num_sysfs_groups = 0;
268
269 flash_groups[num_sysfs_groups++] = &led_flash_strobe_group;
270
271 if (ops->flash_brightness_set)
272 flash_groups[num_sysfs_groups++] = &led_flash_brightness_group;
273
274 if (ops->timeout_set)
275 flash_groups[num_sysfs_groups++] = &led_flash_timeout_group;
276
277 if (ops->fault_get)
278 flash_groups[num_sysfs_groups++] = &led_flash_fault_group;
279
280 led_cdev->groups = flash_groups;
281 }
282
led_classdev_flash_register_ext(struct device * parent,struct led_classdev_flash * fled_cdev,struct led_init_data * init_data)283 int led_classdev_flash_register_ext(struct device *parent,
284 struct led_classdev_flash *fled_cdev,
285 struct led_init_data *init_data)
286 {
287 struct led_classdev *led_cdev;
288 const struct led_flash_ops *ops;
289 int ret;
290
291 if (!fled_cdev)
292 return -EINVAL;
293
294 led_cdev = &fled_cdev->led_cdev;
295
296 if (led_cdev->flags & LED_DEV_CAP_FLASH) {
297 if (!led_cdev->brightness_set_blocking)
298 return -EINVAL;
299
300 ops = fled_cdev->ops;
301 if (!ops || !ops->strobe_set)
302 return -EINVAL;
303
304 led_cdev->flash_resume = led_flash_resume;
305
306 /* Select the sysfs attributes to be created for the device */
307 led_flash_init_sysfs_groups(fled_cdev);
308 }
309
310 /* Register led class device */
311 ret = led_classdev_register_ext(parent, led_cdev, init_data);
312 if (ret < 0)
313 return ret;
314
315 return 0;
316 }
317 EXPORT_SYMBOL_GPL(led_classdev_flash_register_ext);
318
led_classdev_flash_unregister(struct led_classdev_flash * fled_cdev)319 void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev)
320 {
321 if (!fled_cdev)
322 return;
323
324 led_classdev_unregister(&fled_cdev->led_cdev);
325 }
326 EXPORT_SYMBOL_GPL(led_classdev_flash_unregister);
327
devm_led_classdev_flash_release(struct device * dev,void * res)328 static void devm_led_classdev_flash_release(struct device *dev, void *res)
329 {
330 led_classdev_flash_unregister(*(struct led_classdev_flash **)res);
331 }
332
devm_led_classdev_flash_register_ext(struct device * parent,struct led_classdev_flash * fled_cdev,struct led_init_data * init_data)333 int devm_led_classdev_flash_register_ext(struct device *parent,
334 struct led_classdev_flash *fled_cdev,
335 struct led_init_data *init_data)
336 {
337 struct led_classdev_flash **dr;
338 int ret;
339
340 dr = devres_alloc(devm_led_classdev_flash_release, sizeof(*dr),
341 GFP_KERNEL);
342 if (!dr)
343 return -ENOMEM;
344
345 ret = led_classdev_flash_register_ext(parent, fled_cdev, init_data);
346 if (ret) {
347 devres_free(dr);
348 return ret;
349 }
350
351 *dr = fled_cdev;
352 devres_add(parent, dr);
353
354 return 0;
355 }
356 EXPORT_SYMBOL_GPL(devm_led_classdev_flash_register_ext);
357
devm_led_classdev_flash_match(struct device * dev,void * res,void * data)358 static int devm_led_classdev_flash_match(struct device *dev,
359 void *res, void *data)
360 {
361 struct led_classdev_flash **p = res;
362
363 if (WARN_ON(!p || !*p))
364 return 0;
365
366 return *p == data;
367 }
368
devm_led_classdev_flash_unregister(struct device * dev,struct led_classdev_flash * fled_cdev)369 void devm_led_classdev_flash_unregister(struct device *dev,
370 struct led_classdev_flash *fled_cdev)
371 {
372 WARN_ON(devres_release(dev,
373 devm_led_classdev_flash_release,
374 devm_led_classdev_flash_match, fled_cdev));
375 }
376 EXPORT_SYMBOL_GPL(devm_led_classdev_flash_unregister);
377
led_clamp_align(struct led_flash_setting * s)378 static void led_clamp_align(struct led_flash_setting *s)
379 {
380 u32 v, offset;
381
382 v = s->val + s->step / 2;
383 v = clamp(v, s->min, s->max);
384 offset = v - s->min;
385 offset = s->step * (offset / s->step);
386 s->val = s->min + offset;
387 }
388
led_set_flash_timeout(struct led_classdev_flash * fled_cdev,u32 timeout)389 int led_set_flash_timeout(struct led_classdev_flash *fled_cdev, u32 timeout)
390 {
391 struct led_classdev *led_cdev = &fled_cdev->led_cdev;
392 struct led_flash_setting *s = &fled_cdev->timeout;
393
394 s->val = timeout;
395 led_clamp_align(s);
396
397 if (!(led_cdev->flags & LED_SUSPENDED))
398 return call_flash_op(fled_cdev, timeout_set, s->val);
399
400 return 0;
401 }
402 EXPORT_SYMBOL_GPL(led_set_flash_timeout);
403
led_get_flash_fault(struct led_classdev_flash * fled_cdev,u32 * fault)404 int led_get_flash_fault(struct led_classdev_flash *fled_cdev, u32 *fault)
405 {
406 return call_flash_op(fled_cdev, fault_get, fault);
407 }
408 EXPORT_SYMBOL_GPL(led_get_flash_fault);
409
led_set_flash_brightness(struct led_classdev_flash * fled_cdev,u32 brightness)410 int led_set_flash_brightness(struct led_classdev_flash *fled_cdev,
411 u32 brightness)
412 {
413 struct led_classdev *led_cdev = &fled_cdev->led_cdev;
414 struct led_flash_setting *s = &fled_cdev->brightness;
415
416 s->val = brightness;
417 led_clamp_align(s);
418
419 if (!(led_cdev->flags & LED_SUSPENDED))
420 return call_flash_op(fled_cdev, flash_brightness_set, s->val);
421
422 return 0;
423 }
424 EXPORT_SYMBOL_GPL(led_set_flash_brightness);
425
led_update_flash_brightness(struct led_classdev_flash * fled_cdev)426 int led_update_flash_brightness(struct led_classdev_flash *fled_cdev)
427 {
428 struct led_flash_setting *s = &fled_cdev->brightness;
429 u32 brightness;
430
431 if (has_flash_op(fled_cdev, flash_brightness_get)) {
432 int ret = call_flash_op(fled_cdev, flash_brightness_get,
433 &brightness);
434 if (ret < 0)
435 return ret;
436
437 s->val = brightness;
438 }
439
440 return 0;
441 }
442 EXPORT_SYMBOL_GPL(led_update_flash_brightness);
443
444 MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
445 MODULE_DESCRIPTION("LED Flash class interface");
446 MODULE_LICENSE("GPL v2");
447