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 > 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_blocking)
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 return 0;
320}
321EXPORT_SYMBOL_GPL(led_classdev_flash_register);
322
323void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev)
324{
325 if (!fled_cdev)
326 return;
327
328 led_classdev_unregister(&fled_cdev->led_cdev);
329}
330EXPORT_SYMBOL_GPL(led_classdev_flash_unregister);
331
332static void led_clamp_align(struct led_flash_setting *s)
333{
334 u32 v, offset;
335
336 v = s->val + s->step / 2;
337 v = clamp(v, s->min, s->max);
338 offset = v - s->min;
339 offset = s->step * (offset / s->step);
340 s->val = s->min + offset;
341}
342
343int led_set_flash_timeout(struct led_classdev_flash *fled_cdev, u32 timeout)
344{
345 struct led_classdev *led_cdev = &fled_cdev->led_cdev;
346 struct led_flash_setting *s = &fled_cdev->timeout;
347
348 s->val = timeout;
349 led_clamp_align(s);
350
351 if (!(led_cdev->flags & LED_SUSPENDED))
352 return call_flash_op(fled_cdev, timeout_set, s->val);
353
354 return 0;
355}
356EXPORT_SYMBOL_GPL(led_set_flash_timeout);
357
358int led_get_flash_fault(struct led_classdev_flash *fled_cdev, u32 *fault)
359{
360 return call_flash_op(fled_cdev, fault_get, fault);
361}
362EXPORT_SYMBOL_GPL(led_get_flash_fault);
363
364int led_set_flash_brightness(struct led_classdev_flash *fled_cdev,
365 u32 brightness)
366{
367 struct led_classdev *led_cdev = &fled_cdev->led_cdev;
368 struct led_flash_setting *s = &fled_cdev->brightness;
369
370 s->val = brightness;
371 led_clamp_align(s);
372
373 if (!(led_cdev->flags & LED_SUSPENDED))
374 return call_flash_op(fled_cdev, flash_brightness_set, s->val);
375
376 return 0;
377}
378EXPORT_SYMBOL_GPL(led_set_flash_brightness);
379
380int led_update_flash_brightness(struct led_classdev_flash *fled_cdev)
381{
382 struct led_flash_setting *s = &fled_cdev->brightness;
383 u32 brightness;
384
385 if (has_flash_op(fled_cdev, flash_brightness_get)) {
386 int ret = call_flash_op(fled_cdev, flash_brightness_get,
387 &brightness);
388 if (ret < 0)
389 return ret;
390
391 s->val = brightness;
392 }
393
394 return 0;
395}
396EXPORT_SYMBOL_GPL(led_update_flash_brightness);
397
398MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
399MODULE_DESCRIPTION("LED Flash class interface");
400MODULE_LICENSE("GPL v2");
401