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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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