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