1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* LED driver : leds-ktd2692.c
*
* Copyright (C) 2015 Samsung Electronics
* Ingi Kim <ingi2.kim@samsung.com>
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/led-class-flash.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
/* Value related the movie mode */
#define KTD2692_MOVIE_MODE_CURRENT_LEVELS 16
#define KTD2692_MM_TO_FL_RATIO(x) ((x) / 3)
#define KTD2692_MM_MIN_CURR_THRESHOLD_SCALE 8
/* Value related the flash mode */
#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS 8
#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE 0
#define KTD2692_FLASH_MODE_CURR_PERCENT(x) (((x) * 16) / 100)
/* Macro for getting offset of flash timeout */
#define GET_TIMEOUT_OFFSET(timeout, step) ((timeout) / (step))
/* Base register address */
#define KTD2692_REG_LVP_BASE 0x00
#define KTD2692_REG_FLASH_TIMEOUT_BASE 0x20
#define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE 0x40
#define KTD2692_REG_MOVIE_CURRENT_BASE 0x60
#define KTD2692_REG_FLASH_CURRENT_BASE 0x80
#define KTD2692_REG_MODE_BASE 0xA0
/* Set bit coding time for expresswire interface */
#define KTD2692_TIME_RESET_US 700
#define KTD2692_TIME_DATA_START_TIME_US 10
#define KTD2692_TIME_HIGH_END_OF_DATA_US 350
#define KTD2692_TIME_LOW_END_OF_DATA_US 10
#define KTD2692_TIME_SHORT_BITSET_US 4
#define KTD2692_TIME_LONG_BITSET_US 12
/* KTD2692 default length of name */
#define KTD2692_NAME_LENGTH 20
enum ktd2692_bitset {
KTD2692_LOW = 0,
KTD2692_HIGH,
};
/* Movie / Flash Mode Control */
enum ktd2692_led_mode {
KTD2692_MODE_DISABLE = 0, /* default */
KTD2692_MODE_MOVIE,
KTD2692_MODE_FLASH,
};
struct ktd2692_led_config_data {
/* maximum LED current in movie mode */
u32 movie_max_microamp;
/* maximum LED current in flash mode */
u32 flash_max_microamp;
/* maximum flash timeout */
u32 flash_max_timeout;
/* max LED brightness level */
enum led_brightness max_brightness;
};
struct ktd2692_context {
/* Related LED Flash class device */
struct led_classdev_flash fled_cdev;
/* secures access to the device */
struct mutex lock;
struct regulator *regulator;
struct gpio_desc *aux_gpio;
struct gpio_desc *ctrl_gpio;
enum ktd2692_led_mode mode;
enum led_brightness torch_brightness;
};
static struct ktd2692_context *fled_cdev_to_led(
struct led_classdev_flash *fled_cdev)
{
return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
}
static void ktd2692_expresswire_start(struct ktd2692_context *led)
{
gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
udelay(KTD2692_TIME_DATA_START_TIME_US);
}
static void ktd2692_expresswire_reset(struct ktd2692_context *led)
{
gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
udelay(KTD2692_TIME_RESET_US);
}
static void ktd2692_expresswire_end(struct ktd2692_context *led)
{
gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
}
static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
{
/*
* The Low Bit(0) and High Bit(1) is based on a time detection
* algorithm between time low and time high
* Time_(L_LB) : Low time of the Low Bit(0)
* Time_(H_LB) : High time of the LOW Bit(0)
* Time_(L_HB) : Low time of the High Bit(1)
* Time_(H_HB) : High time of the High Bit(1)
*
* It can be simplified to:
* Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
* High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
* HIGH ___ ____ _.. _________ ___
* |_________| |_.. |____| |__|
* LOW <L_LB> <H_LB> <L_HB> <H_HB>
* [ Low Bit (0) ] [ High Bit(1) ]
*/
if (bit) {
gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
udelay(KTD2692_TIME_SHORT_BITSET_US);
gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
udelay(KTD2692_TIME_LONG_BITSET_US);
} else {
gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
udelay(KTD2692_TIME_LONG_BITSET_US);
gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
udelay(KTD2692_TIME_SHORT_BITSET_US);
}
}
static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
{
int i;
ktd2692_expresswire_start(led);
for (i = 7; i >= 0; i--)
ktd2692_expresswire_set_bit(led, value & BIT(i));
ktd2692_expresswire_end(led);
}
static int ktd2692_led_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
mutex_lock(&led->lock);
if (brightness == LED_OFF) {
led->mode = KTD2692_MODE_DISABLE;
gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
} else {
ktd2692_expresswire_write(led, brightness |
KTD2692_REG_MOVIE_CURRENT_BASE);
led->mode = KTD2692_MODE_MOVIE;
}
ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
mutex_unlock(&led->lock);
return 0;
}
static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
bool state)
{
struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
struct led_flash_setting *timeout = &fled_cdev->timeout;
u32 flash_tm_reg;
mutex_lock(&led->lock);
if (state) {
flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
ktd2692_expresswire_write(led, flash_tm_reg
| KTD2692_REG_FLASH_TIMEOUT_BASE);
led->mode = KTD2692_MODE_FLASH;
gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
} else {
led->mode = KTD2692_MODE_DISABLE;
gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
}
ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
fled_cdev->led_cdev.brightness = LED_OFF;
led->mode = KTD2692_MODE_DISABLE;
mutex_unlock(&led->lock);
return 0;
}
static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
u32 timeout)
{
return 0;
}
static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
{
u32 offset, step;
u32 movie_current_microamp;
offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
/ KTD2692_MOVIE_MODE_CURRENT_LEVELS;
do {
movie_current_microamp = step * offset;
offset--;
} while ((movie_current_microamp > cfg->movie_max_microamp) &&
(offset > 0));
cfg->max_brightness = offset;
}
static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
struct ktd2692_led_config_data *cfg)
{
struct led_flash_setting *setting;
setting = &fled_cdev->timeout;
setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
setting->max = cfg->flash_max_timeout;
setting->step = cfg->flash_max_timeout
/ (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
setting->val = cfg->flash_max_timeout;
}
static void ktd2692_setup(struct ktd2692_context *led)
{
led->mode = KTD2692_MODE_DISABLE;
ktd2692_expresswire_reset(led);
gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
ktd2692_expresswire_write(led, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)
| KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
| KTD2692_REG_FLASH_CURRENT_BASE);
}
static void regulator_disable_action(void *_data)
{
struct device *dev = _data;
struct ktd2692_context *led = dev_get_drvdata(dev);
int ret;
ret = regulator_disable(led->regulator);
if (ret)
dev_err(dev, "Failed to disable supply: %d\n", ret);
}
static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
struct ktd2692_led_config_data *cfg)
{
struct device_node *np = dev_of_node(dev);
struct device_node *child_node;
int ret;
if (!np)
return -ENXIO;
led->ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS);
ret = PTR_ERR_OR_ZERO(led->ctrl_gpio);
if (ret)
return dev_err_probe(dev, ret, "cannot get ctrl-gpios\n");
led->aux_gpio = devm_gpiod_get_optional(dev, "aux", GPIOD_ASIS);
if (IS_ERR(led->aux_gpio))
return dev_err_probe(dev, PTR_ERR(led->aux_gpio), "cannot get aux-gpios\n");
led->regulator = devm_regulator_get(dev, "vin");
if (IS_ERR(led->regulator))
led->regulator = NULL;
if (led->regulator) {
ret = regulator_enable(led->regulator);
if (ret) {
dev_err(dev, "Failed to enable supply: %d\n", ret);
} else {
ret = devm_add_action_or_reset(dev,
regulator_disable_action, dev);
if (ret)
return ret;
}
}
child_node = of_get_next_available_child(np, NULL);
if (!child_node) {
dev_err(dev, "No DT child node found for connected LED.\n");
return -EINVAL;
}
led->fled_cdev.led_cdev.name =
of_get_property(child_node, "label", NULL) ? : child_node->name;
ret = of_property_read_u32(child_node, "led-max-microamp",
&cfg->movie_max_microamp);
if (ret) {
dev_err(dev, "failed to parse led-max-microamp\n");
goto err_parse_dt;
}
ret = of_property_read_u32(child_node, "flash-max-microamp",
&cfg->flash_max_microamp);
if (ret) {
dev_err(dev, "failed to parse flash-max-microamp\n");
goto err_parse_dt;
}
ret = of_property_read_u32(child_node, "flash-max-timeout-us",
&cfg->flash_max_timeout);
if (ret) {
dev_err(dev, "failed to parse flash-max-timeout-us\n");
goto err_parse_dt;
}
err_parse_dt:
of_node_put(child_node);
return ret;
}
static const struct led_flash_ops flash_ops = {
.strobe_set = ktd2692_led_flash_strobe_set,
.timeout_set = ktd2692_led_flash_timeout_set,
};
static int ktd2692_probe(struct platform_device *pdev)
{
struct ktd2692_context *led;
struct led_classdev *led_cdev;
struct led_classdev_flash *fled_cdev;
struct ktd2692_led_config_data led_cfg;
int ret;
led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
if (!led)
return -ENOMEM;
fled_cdev = &led->fled_cdev;
led_cdev = &fled_cdev->led_cdev;
ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
if (ret)
return ret;
ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
ktd2692_init_movie_current_max(&led_cfg);
fled_cdev->ops = &flash_ops;
led_cdev->max_brightness = led_cfg.max_brightness;
led_cdev->brightness_set_blocking = ktd2692_led_brightness_set;
led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
mutex_init(&led->lock);
platform_set_drvdata(pdev, led);
ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
if (ret) {
dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
mutex_destroy(&led->lock);
return ret;
}
ktd2692_setup(led);
return 0;
}
static void ktd2692_remove(struct platform_device *pdev)
{
struct ktd2692_context *led = platform_get_drvdata(pdev);
led_classdev_flash_unregister(&led->fled_cdev);
mutex_destroy(&led->lock);
}
static const struct of_device_id ktd2692_match[] = {
{ .compatible = "kinetic,ktd2692", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, ktd2692_match);
static struct platform_driver ktd2692_driver = {
.driver = {
.name = "ktd2692",
.of_match_table = ktd2692_match,
},
.probe = ktd2692_probe,
.remove_new = ktd2692_remove,
};
module_platform_driver(ktd2692_driver);
MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
MODULE_LICENSE("GPL v2");
|
