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