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9#include <linux/delay.h>
10#include <linux/err.h>
11#include <linux/gpio/consumer.h>
12#include <linux/led-class-flash.h>
13#include <linux/module.h>
14#include <linux/mutex.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/regulator/consumer.h>
18
19
20#define KTD2692_MOVIE_MODE_CURRENT_LEVELS 16
21#define KTD2692_MM_TO_FL_RATIO(x) ((x) / 3)
22#define KTD2692_MM_MIN_CURR_THRESHOLD_SCALE 8
23
24
25#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS 8
26#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE 0
27#define KTD2692_FLASH_MODE_CURR_PERCENT(x) (((x) * 16) / 100)
28
29
30#define GET_TIMEOUT_OFFSET(timeout, step) ((timeout) / (step))
31
32
33#define KTD2692_REG_LVP_BASE 0x00
34#define KTD2692_REG_FLASH_TIMEOUT_BASE 0x20
35#define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE 0x40
36#define KTD2692_REG_MOVIE_CURRENT_BASE 0x60
37#define KTD2692_REG_FLASH_CURRENT_BASE 0x80
38#define KTD2692_REG_MODE_BASE 0xA0
39
40
41#define KTD2692_TIME_RESET_US 700
42#define KTD2692_TIME_DATA_START_TIME_US 10
43#define KTD2692_TIME_HIGH_END_OF_DATA_US 350
44#define KTD2692_TIME_LOW_END_OF_DATA_US 10
45#define KTD2692_TIME_SHORT_BITSET_US 4
46#define KTD2692_TIME_LONG_BITSET_US 12
47
48
49#define KTD2692_NAME_LENGTH 20
50
51enum ktd2692_bitset {
52 KTD2692_LOW = 0,
53 KTD2692_HIGH,
54};
55
56
57enum ktd2692_led_mode {
58 KTD2692_MODE_DISABLE = 0,
59 KTD2692_MODE_MOVIE,
60 KTD2692_MODE_FLASH,
61};
62
63struct ktd2692_led_config_data {
64
65 u32 movie_max_microamp;
66
67 u32 flash_max_microamp;
68
69 u32 flash_max_timeout;
70
71 enum led_brightness max_brightness;
72};
73
74struct ktd2692_context {
75
76 struct led_classdev_flash fled_cdev;
77
78
79 struct mutex lock;
80 struct regulator *regulator;
81
82 struct gpio_desc *aux_gpio;
83 struct gpio_desc *ctrl_gpio;
84
85 enum ktd2692_led_mode mode;
86 enum led_brightness torch_brightness;
87};
88
89static struct ktd2692_context *fled_cdev_to_led(
90 struct led_classdev_flash *fled_cdev)
91{
92 return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
93}
94
95static void ktd2692_expresswire_start(struct ktd2692_context *led)
96{
97 gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
98 udelay(KTD2692_TIME_DATA_START_TIME_US);
99}
100
101static void ktd2692_expresswire_reset(struct ktd2692_context *led)
102{
103 gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
104 udelay(KTD2692_TIME_RESET_US);
105}
106
107static void ktd2692_expresswire_end(struct ktd2692_context *led)
108{
109 gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
110 udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
111 gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
112 udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
113}
114
115static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
116{
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132
133 if (bit) {
134 gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
135 udelay(KTD2692_TIME_SHORT_BITSET_US);
136 gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
137 udelay(KTD2692_TIME_LONG_BITSET_US);
138 } else {
139 gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
140 udelay(KTD2692_TIME_LONG_BITSET_US);
141 gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
142 udelay(KTD2692_TIME_SHORT_BITSET_US);
143 }
144}
145
146static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
147{
148 int i;
149
150 ktd2692_expresswire_start(led);
151 for (i = 7; i >= 0; i--)
152 ktd2692_expresswire_set_bit(led, value & BIT(i));
153 ktd2692_expresswire_end(led);
154}
155
156static int ktd2692_led_brightness_set(struct led_classdev *led_cdev,
157 enum led_brightness brightness)
158{
159 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
160 struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
161
162 mutex_lock(&led->lock);
163
164 if (brightness == LED_OFF) {
165 led->mode = KTD2692_MODE_DISABLE;
166 gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
167 } else {
168 ktd2692_expresswire_write(led, brightness |
169 KTD2692_REG_MOVIE_CURRENT_BASE);
170 led->mode = KTD2692_MODE_MOVIE;
171 }
172
173 ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
174 mutex_unlock(&led->lock);
175
176 return 0;
177}
178
179static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
180 bool state)
181{
182 struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
183 struct led_flash_setting *timeout = &fled_cdev->timeout;
184 u32 flash_tm_reg;
185
186 mutex_lock(&led->lock);
187
188 if (state) {
189 flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
190 ktd2692_expresswire_write(led, flash_tm_reg
191 | KTD2692_REG_FLASH_TIMEOUT_BASE);
192
193 led->mode = KTD2692_MODE_FLASH;
194 gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
195 } else {
196 led->mode = KTD2692_MODE_DISABLE;
197 gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
198 }
199
200 ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
201
202 fled_cdev->led_cdev.brightness = LED_OFF;
203 led->mode = KTD2692_MODE_DISABLE;
204
205 mutex_unlock(&led->lock);
206
207 return 0;
208}
209
210static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
211 u32 timeout)
212{
213 return 0;
214}
215
216static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
217{
218 u32 offset, step;
219 u32 movie_current_microamp;
220
221 offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
222 step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
223 / KTD2692_MOVIE_MODE_CURRENT_LEVELS;
224
225 do {
226 movie_current_microamp = step * offset;
227 offset--;
228 } while ((movie_current_microamp > cfg->movie_max_microamp) &&
229 (offset > 0));
230
231 cfg->max_brightness = offset;
232}
233
234static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
235 struct ktd2692_led_config_data *cfg)
236{
237 struct led_flash_setting *setting;
238
239 setting = &fled_cdev->timeout;
240 setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
241 setting->max = cfg->flash_max_timeout;
242 setting->step = cfg->flash_max_timeout
243 / (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
244 setting->val = cfg->flash_max_timeout;
245}
246
247static void ktd2692_setup(struct ktd2692_context *led)
248{
249 led->mode = KTD2692_MODE_DISABLE;
250 ktd2692_expresswire_reset(led);
251 gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
252
253 ktd2692_expresswire_write(led, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)
254 | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
255 ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
256 | KTD2692_REG_FLASH_CURRENT_BASE);
257}
258
259static void regulator_disable_action(void *_data)
260{
261 struct device *dev = _data;
262 struct ktd2692_context *led = dev_get_drvdata(dev);
263 int ret;
264
265 ret = regulator_disable(led->regulator);
266 if (ret)
267 dev_err(dev, "Failed to disable supply: %d\n", ret);
268}
269
270static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
271 struct ktd2692_led_config_data *cfg)
272{
273 struct device_node *np = dev_of_node(dev);
274 struct device_node *child_node;
275 int ret;
276
277 if (!dev_of_node(dev))
278 return -ENXIO;
279
280 led->ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS);
281 ret = PTR_ERR_OR_ZERO(led->ctrl_gpio);
282 if (ret) {
283 dev_err(dev, "cannot get ctrl-gpios %d\n", ret);
284 return ret;
285 }
286
287 led->aux_gpio = devm_gpiod_get(dev, "aux", GPIOD_ASIS);
288 ret = PTR_ERR_OR_ZERO(led->aux_gpio);
289 if (ret) {
290 dev_err(dev, "cannot get aux-gpios %d\n", ret);
291 return ret;
292 }
293
294 led->regulator = devm_regulator_get(dev, "vin");
295 if (IS_ERR(led->regulator))
296 led->regulator = NULL;
297
298 if (led->regulator) {
299 ret = regulator_enable(led->regulator);
300 if (ret) {
301 dev_err(dev, "Failed to enable supply: %d\n", ret);
302 } else {
303 ret = devm_add_action_or_reset(dev,
304 regulator_disable_action, dev);
305 if (ret)
306 return ret;
307 }
308 }
309
310 child_node = of_get_next_available_child(np, NULL);
311 if (!child_node) {
312 dev_err(dev, "No DT child node found for connected LED.\n");
313 return -EINVAL;
314 }
315
316 led->fled_cdev.led_cdev.name =
317 of_get_property(child_node, "label", NULL) ? : child_node->name;
318
319 ret = of_property_read_u32(child_node, "led-max-microamp",
320 &cfg->movie_max_microamp);
321 if (ret) {
322 dev_err(dev, "failed to parse led-max-microamp\n");
323 goto err_parse_dt;
324 }
325
326 ret = of_property_read_u32(child_node, "flash-max-microamp",
327 &cfg->flash_max_microamp);
328 if (ret) {
329 dev_err(dev, "failed to parse flash-max-microamp\n");
330 goto err_parse_dt;
331 }
332
333 ret = of_property_read_u32(child_node, "flash-max-timeout-us",
334 &cfg->flash_max_timeout);
335 if (ret) {
336 dev_err(dev, "failed to parse flash-max-timeout-us\n");
337 goto err_parse_dt;
338 }
339
340err_parse_dt:
341 of_node_put(child_node);
342 return ret;
343}
344
345static const struct led_flash_ops flash_ops = {
346 .strobe_set = ktd2692_led_flash_strobe_set,
347 .timeout_set = ktd2692_led_flash_timeout_set,
348};
349
350static int ktd2692_probe(struct platform_device *pdev)
351{
352 struct ktd2692_context *led;
353 struct led_classdev *led_cdev;
354 struct led_classdev_flash *fled_cdev;
355 struct ktd2692_led_config_data led_cfg;
356 int ret;
357
358 led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
359 if (!led)
360 return -ENOMEM;
361
362 fled_cdev = &led->fled_cdev;
363 led_cdev = &fled_cdev->led_cdev;
364
365 ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
366 if (ret)
367 return ret;
368
369 ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
370 ktd2692_init_movie_current_max(&led_cfg);
371
372 fled_cdev->ops = &flash_ops;
373
374 led_cdev->max_brightness = led_cfg.max_brightness;
375 led_cdev->brightness_set_blocking = ktd2692_led_brightness_set;
376 led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
377
378 mutex_init(&led->lock);
379
380 platform_set_drvdata(pdev, led);
381
382 ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
383 if (ret) {
384 dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
385 mutex_destroy(&led->lock);
386 return ret;
387 }
388
389 ktd2692_setup(led);
390
391 return 0;
392}
393
394static int ktd2692_remove(struct platform_device *pdev)
395{
396 struct ktd2692_context *led = platform_get_drvdata(pdev);
397
398 led_classdev_flash_unregister(&led->fled_cdev);
399
400 mutex_destroy(&led->lock);
401
402 return 0;
403}
404
405static const struct of_device_id ktd2692_match[] = {
406 { .compatible = "kinetic,ktd2692", },
407 { },
408};
409MODULE_DEVICE_TABLE(of, ktd2692_match);
410
411static struct platform_driver ktd2692_driver = {
412 .driver = {
413 .name = "ktd2692",
414 .of_match_table = ktd2692_match,
415 },
416 .probe = ktd2692_probe,
417 .remove = ktd2692_remove,
418};
419
420module_platform_driver(ktd2692_driver);
421
422MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
423MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
424MODULE_LICENSE("GPL v2");
425
