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
28static 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
40static 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;
64unlock:
65	mutex_unlock(&led_cdev->led_access);
66	return ret;
67}
68
69static 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}
80static DEVICE_ATTR_RW(flash_brightness);
81
82static 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}
90static DEVICE_ATTR_RO(max_flash_brightness);
91
92static 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;
120unlock:
121	mutex_unlock(&led_cdev->led_access);
122	return ret;
123}
124
125static 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}
140static DEVICE_ATTR_RW(flash_strobe);
141
142static 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;
166unlock:
167	mutex_unlock(&led_cdev->led_access);
168	return ret;
169}
170
171static 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}
179static DEVICE_ATTR_RW(flash_timeout);
180
181static 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}
189static DEVICE_ATTR_RO(max_flash_timeout);
190
191static 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}
217static DEVICE_ATTR_RO(flash_fault);
218
219static struct attribute *led_flash_strobe_attrs[] = {
220	&dev_attr_flash_strobe.attr,
221	NULL,
222};
223
224static struct attribute *led_flash_timeout_attrs[] = {
225	&dev_attr_flash_timeout.attr,
226	&dev_attr_max_flash_timeout.attr,
227	NULL,
228};
229
230static struct attribute *led_flash_brightness_attrs[] = {
231	&dev_attr_flash_brightness.attr,
232	&dev_attr_max_flash_brightness.attr,
233	NULL,
234};
235
236static struct attribute *led_flash_fault_attrs[] = {
237	&dev_attr_flash_fault.attr,
238	NULL,
239};
240
241static const struct attribute_group led_flash_strobe_group = {
242	.attrs = led_flash_strobe_attrs,
243};
244
245static const struct attribute_group led_flash_timeout_group = {
246	.attrs = led_flash_timeout_attrs,
247};
248
249static const struct attribute_group led_flash_brightness_group = {
250	.attrs = led_flash_brightness_attrs,
251};
252
253static const struct attribute_group led_flash_fault_group = {
254	.attrs = led_flash_fault_attrs,
255};
256
257static 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
266static 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
288int 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}
325EXPORT_SYMBOL_GPL(led_classdev_flash_register);
326
327void 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}
334EXPORT_SYMBOL_GPL(led_classdev_flash_unregister);
335
336static 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
347int 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}
360EXPORT_SYMBOL_GPL(led_set_flash_timeout);
361
362int led_get_flash_fault(struct led_classdev_flash *fled_cdev, u32 *fault)
363{
364	return call_flash_op(fled_cdev, fault_get, fault);
365}
366EXPORT_SYMBOL_GPL(led_get_flash_fault);
367
368int 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}
382EXPORT_SYMBOL_GPL(led_set_flash_brightness);
383
384int 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}
400EXPORT_SYMBOL_GPL(led_update_flash_brightness);
401
402MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
403MODULE_DESCRIPTION("LED Flash class interface");
404MODULE_LICENSE("GPL v2");
405