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b7da8c5c IK |
1 | /* |
2 | * LED driver : leds-ktd2692.c | |
3 | * | |
4 | * Copyright (C) 2015 Samsung Electronics | |
5 | * Ingi Kim <ingi2.kim@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/delay.h> | |
13 | #include <linux/err.h> | |
14 | #include <linux/gpio/consumer.h> | |
15 | #include <linux/led-class-flash.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/mutex.h> | |
18 | #include <linux/of.h> | |
19 | #include <linux/platform_device.h> | |
20 | #include <linux/regulator/consumer.h> | |
21 | #include <linux/workqueue.h> | |
22 | ||
23 | /* Value related the movie mode */ | |
24 | #define KTD2692_MOVIE_MODE_CURRENT_LEVELS 16 | |
25 | #define KTD2692_MM_TO_FL_RATIO(x) ((x) / 3) | |
26 | #define KTD2962_MM_MIN_CURR_THRESHOLD_SCALE 8 | |
27 | ||
28 | /* Value related the flash mode */ | |
29 | #define KTD2692_FLASH_MODE_TIMEOUT_LEVELS 8 | |
30 | #define KTD2692_FLASH_MODE_TIMEOUT_DISABLE 0 | |
31 | #define KTD2692_FLASH_MODE_CURR_PERCENT(x) (((x) * 16) / 100) | |
32 | ||
33 | /* Macro for getting offset of flash timeout */ | |
34 | #define GET_TIMEOUT_OFFSET(timeout, step) ((timeout) / (step)) | |
35 | ||
36 | /* Base register address */ | |
37 | #define KTD2692_REG_LVP_BASE 0x00 | |
38 | #define KTD2692_REG_FLASH_TIMEOUT_BASE 0x20 | |
39 | #define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE 0x40 | |
40 | #define KTD2692_REG_MOVIE_CURRENT_BASE 0x60 | |
41 | #define KTD2692_REG_FLASH_CURRENT_BASE 0x80 | |
42 | #define KTD2692_REG_MODE_BASE 0xA0 | |
43 | ||
44 | /* Set bit coding time for expresswire interface */ | |
45 | #define KTD2692_TIME_RESET_US 700 | |
46 | #define KTD2692_TIME_DATA_START_TIME_US 10 | |
47 | #define KTD2692_TIME_HIGH_END_OF_DATA_US 350 | |
48 | #define KTD2692_TIME_LOW_END_OF_DATA_US 10 | |
49 | #define KTD2692_TIME_SHORT_BITSET_US 4 | |
50 | #define KTD2692_TIME_LONG_BITSET_US 12 | |
51 | ||
52 | /* KTD2692 default length of name */ | |
53 | #define KTD2692_NAME_LENGTH 20 | |
54 | ||
55 | enum ktd2692_bitset { | |
56 | KTD2692_LOW = 0, | |
57 | KTD2692_HIGH, | |
58 | }; | |
59 | ||
60 | /* Movie / Flash Mode Control */ | |
61 | enum ktd2692_led_mode { | |
62 | KTD2692_MODE_DISABLE = 0, /* default */ | |
63 | KTD2692_MODE_MOVIE, | |
64 | KTD2692_MODE_FLASH, | |
65 | }; | |
66 | ||
67 | struct ktd2692_led_config_data { | |
68 | /* maximum LED current in movie mode */ | |
69 | u32 movie_max_microamp; | |
70 | /* maximum LED current in flash mode */ | |
71 | u32 flash_max_microamp; | |
72 | /* maximum flash timeout */ | |
73 | u32 flash_max_timeout; | |
74 | /* max LED brightness level */ | |
75 | enum led_brightness max_brightness; | |
76 | }; | |
77 | ||
78 | struct ktd2692_context { | |
79 | /* Related LED Flash class device */ | |
80 | struct led_classdev_flash fled_cdev; | |
81 | ||
82 | /* secures access to the device */ | |
83 | struct mutex lock; | |
84 | struct regulator *regulator; | |
85 | struct work_struct work_brightness_set; | |
86 | ||
87 | struct gpio_desc *aux_gpio; | |
88 | struct gpio_desc *ctrl_gpio; | |
89 | ||
90 | enum ktd2692_led_mode mode; | |
91 | enum led_brightness torch_brightness; | |
92 | }; | |
93 | ||
94 | static struct ktd2692_context *fled_cdev_to_led( | |
95 | struct led_classdev_flash *fled_cdev) | |
96 | { | |
97 | return container_of(fled_cdev, struct ktd2692_context, fled_cdev); | |
98 | } | |
99 | ||
100 | static void ktd2692_expresswire_start(struct ktd2692_context *led) | |
101 | { | |
102 | gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH); | |
103 | udelay(KTD2692_TIME_DATA_START_TIME_US); | |
104 | } | |
105 | ||
106 | static void ktd2692_expresswire_reset(struct ktd2692_context *led) | |
107 | { | |
108 | gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW); | |
109 | udelay(KTD2692_TIME_RESET_US); | |
110 | } | |
111 | ||
112 | static void ktd2692_expresswire_end(struct ktd2692_context *led) | |
113 | { | |
114 | gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW); | |
115 | udelay(KTD2692_TIME_LOW_END_OF_DATA_US); | |
116 | gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH); | |
117 | udelay(KTD2692_TIME_HIGH_END_OF_DATA_US); | |
118 | } | |
119 | ||
120 | static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit) | |
121 | { | |
122 | /* | |
123 | * The Low Bit(0) and High Bit(1) is based on a time detection | |
124 | * algorithm between time low and time high | |
125 | * Time_(L_LB) : Low time of the Low Bit(0) | |
126 | * Time_(H_LB) : High time of the LOW Bit(0) | |
127 | * Time_(L_HB) : Low time of the High Bit(1) | |
128 | * Time_(H_HB) : High time of the High Bit(1) | |
129 | * | |
130 | * It can be simplified to: | |
131 | * Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB) | |
132 | * High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB) | |
133 | * HIGH ___ ____ _.. _________ ___ | |
134 | * |_________| |_.. |____| |__| | |
135 | * LOW <L_LB> <H_LB> <L_HB> <H_HB> | |
136 | * [ Low Bit (0) ] [ High Bit(1) ] | |
137 | */ | |
138 | if (bit) { | |
139 | gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW); | |
140 | udelay(KTD2692_TIME_SHORT_BITSET_US); | |
141 | gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH); | |
142 | udelay(KTD2692_TIME_LONG_BITSET_US); | |
143 | } else { | |
144 | gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW); | |
145 | udelay(KTD2692_TIME_LONG_BITSET_US); | |
146 | gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH); | |
147 | udelay(KTD2692_TIME_SHORT_BITSET_US); | |
148 | } | |
149 | } | |
150 | ||
151 | static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value) | |
152 | { | |
153 | int i; | |
154 | ||
155 | ktd2692_expresswire_start(led); | |
156 | for (i = 7; i >= 0; i--) | |
157 | ktd2692_expresswire_set_bit(led, value & BIT(i)); | |
158 | ktd2692_expresswire_end(led); | |
159 | } | |
160 | ||
161 | static void ktd2692_brightness_set(struct ktd2692_context *led, | |
162 | enum led_brightness brightness) | |
163 | { | |
164 | mutex_lock(&led->lock); | |
165 | ||
166 | if (brightness == LED_OFF) { | |
167 | led->mode = KTD2692_MODE_DISABLE; | |
168 | gpiod_direction_output(led->aux_gpio, KTD2692_LOW); | |
169 | } else { | |
170 | ktd2692_expresswire_write(led, brightness | | |
171 | KTD2692_REG_MOVIE_CURRENT_BASE); | |
172 | led->mode = KTD2692_MODE_MOVIE; | |
173 | } | |
174 | ||
175 | ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE); | |
176 | mutex_unlock(&led->lock); | |
177 | } | |
178 | ||
179 | static void ktd2692_brightness_set_work(struct work_struct *work) | |
180 | { | |
181 | struct ktd2692_context *led = | |
182 | container_of(work, struct ktd2692_context, work_brightness_set); | |
183 | ||
184 | ktd2692_brightness_set(led, led->torch_brightness); | |
185 | } | |
186 | ||
187 | static void ktd2692_led_brightness_set(struct led_classdev *led_cdev, | |
188 | enum led_brightness brightness) | |
189 | { | |
190 | struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); | |
191 | struct ktd2692_context *led = fled_cdev_to_led(fled_cdev); | |
192 | ||
193 | led->torch_brightness = brightness; | |
194 | schedule_work(&led->work_brightness_set); | |
195 | } | |
196 | ||
197 | static int ktd2692_led_brightness_set_sync(struct led_classdev *led_cdev, | |
198 | enum led_brightness brightness) | |
199 | { | |
200 | struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); | |
201 | struct ktd2692_context *led = fled_cdev_to_led(fled_cdev); | |
202 | ||
203 | ktd2692_brightness_set(led, brightness); | |
204 | ||
205 | return 0; | |
206 | } | |
207 | ||
208 | static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev, | |
209 | bool state) | |
210 | { | |
211 | struct ktd2692_context *led = fled_cdev_to_led(fled_cdev); | |
212 | struct led_flash_setting *timeout = &fled_cdev->timeout; | |
213 | u32 flash_tm_reg; | |
214 | ||
215 | mutex_lock(&led->lock); | |
216 | ||
217 | if (state) { | |
218 | flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step); | |
219 | ktd2692_expresswire_write(led, flash_tm_reg | |
220 | | KTD2692_REG_FLASH_TIMEOUT_BASE); | |
221 | ||
222 | led->mode = KTD2692_MODE_FLASH; | |
223 | gpiod_direction_output(led->aux_gpio, KTD2692_HIGH); | |
224 | } else { | |
225 | led->mode = KTD2692_MODE_DISABLE; | |
226 | gpiod_direction_output(led->aux_gpio, KTD2692_LOW); | |
227 | } | |
228 | ||
229 | ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE); | |
230 | ||
231 | fled_cdev->led_cdev.brightness = LED_OFF; | |
232 | led->mode = KTD2692_MODE_DISABLE; | |
233 | ||
234 | mutex_unlock(&led->lock); | |
235 | ||
236 | return 0; | |
237 | } | |
238 | ||
239 | static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev, | |
240 | u32 timeout) | |
241 | { | |
242 | return 0; | |
243 | } | |
244 | ||
245 | static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg) | |
246 | { | |
247 | u32 offset, step; | |
248 | u32 movie_current_microamp; | |
249 | ||
250 | offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS; | |
251 | step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp) | |
252 | / KTD2692_MOVIE_MODE_CURRENT_LEVELS; | |
253 | ||
254 | do { | |
255 | movie_current_microamp = step * offset; | |
256 | offset--; | |
257 | } while ((movie_current_microamp > cfg->movie_max_microamp) && | |
258 | (offset > 0)); | |
259 | ||
260 | cfg->max_brightness = offset; | |
261 | } | |
262 | ||
263 | static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev, | |
264 | struct ktd2692_led_config_data *cfg) | |
265 | { | |
266 | struct led_flash_setting *setting; | |
267 | ||
268 | setting = &fled_cdev->timeout; | |
269 | setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE; | |
270 | setting->max = cfg->flash_max_timeout; | |
271 | setting->step = cfg->flash_max_timeout | |
272 | / (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1); | |
273 | setting->val = cfg->flash_max_timeout; | |
274 | } | |
275 | ||
276 | static void ktd2692_setup(struct ktd2692_context *led) | |
277 | { | |
278 | led->mode = KTD2692_MODE_DISABLE; | |
279 | ktd2692_expresswire_reset(led); | |
280 | gpiod_direction_output(led->aux_gpio, KTD2692_LOW); | |
281 | ||
282 | ktd2692_expresswire_write(led, (KTD2962_MM_MIN_CURR_THRESHOLD_SCALE - 1) | |
283 | | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE); | |
284 | ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45) | |
285 | | KTD2692_REG_FLASH_CURRENT_BASE); | |
286 | } | |
287 | ||
288 | static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev, | |
289 | struct ktd2692_led_config_data *cfg) | |
290 | { | |
291 | struct device_node *np = dev->of_node; | |
292 | struct device_node *child_node; | |
293 | int ret; | |
294 | ||
295 | if (!dev->of_node) | |
296 | return -ENXIO; | |
297 | ||
5e324ebf | 298 | led->ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS); |
b7da8c5c IK |
299 | if (IS_ERR(led->ctrl_gpio)) { |
300 | ret = PTR_ERR(led->ctrl_gpio); | |
301 | dev_err(dev, "cannot get ctrl-gpios %d\n", ret); | |
302 | return ret; | |
303 | } | |
304 | ||
5e324ebf | 305 | led->aux_gpio = devm_gpiod_get(dev, "aux", GPIOD_ASIS); |
b7da8c5c IK |
306 | if (IS_ERR(led->aux_gpio)) { |
307 | ret = PTR_ERR(led->aux_gpio); | |
308 | dev_err(dev, "cannot get aux-gpios %d\n", ret); | |
309 | return ret; | |
310 | } | |
311 | ||
312 | led->regulator = devm_regulator_get(dev, "vin"); | |
313 | if (IS_ERR(led->regulator)) | |
314 | led->regulator = NULL; | |
315 | ||
316 | if (led->regulator) { | |
317 | ret = regulator_enable(led->regulator); | |
318 | if (ret) | |
319 | dev_err(dev, "Failed to enable supply: %d\n", ret); | |
320 | } | |
321 | ||
322 | child_node = of_get_next_available_child(np, NULL); | |
323 | if (!child_node) { | |
324 | dev_err(dev, "No DT child node found for connected LED.\n"); | |
325 | return -EINVAL; | |
326 | } | |
327 | ||
328 | led->fled_cdev.led_cdev.name = | |
329 | of_get_property(child_node, "label", NULL) ? : child_node->name; | |
330 | ||
331 | ret = of_property_read_u32(child_node, "led-max-microamp", | |
332 | &cfg->movie_max_microamp); | |
333 | if (ret) { | |
334 | dev_err(dev, "failed to parse led-max-microamp\n"); | |
335 | return ret; | |
336 | } | |
337 | ||
338 | ret = of_property_read_u32(child_node, "flash-max-microamp", | |
339 | &cfg->flash_max_microamp); | |
340 | if (ret) { | |
341 | dev_err(dev, "failed to parse flash-max-microamp\n"); | |
342 | return ret; | |
343 | } | |
344 | ||
345 | ret = of_property_read_u32(child_node, "flash-max-timeout-us", | |
346 | &cfg->flash_max_timeout); | |
347 | if (ret) | |
348 | dev_err(dev, "failed to parse flash-max-timeout-us\n"); | |
349 | ||
350 | of_node_put(child_node); | |
351 | return ret; | |
352 | } | |
353 | ||
354 | static const struct led_flash_ops flash_ops = { | |
355 | .strobe_set = ktd2692_led_flash_strobe_set, | |
356 | .timeout_set = ktd2692_led_flash_timeout_set, | |
357 | }; | |
358 | ||
359 | static int ktd2692_probe(struct platform_device *pdev) | |
360 | { | |
361 | struct ktd2692_context *led; | |
362 | struct led_classdev *led_cdev; | |
363 | struct led_classdev_flash *fled_cdev; | |
364 | struct ktd2692_led_config_data led_cfg; | |
365 | int ret; | |
366 | ||
367 | led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL); | |
368 | if (!led) | |
369 | return -ENOMEM; | |
370 | ||
371 | fled_cdev = &led->fled_cdev; | |
372 | led_cdev = &fled_cdev->led_cdev; | |
373 | ||
374 | ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg); | |
375 | if (ret) | |
376 | return ret; | |
377 | ||
378 | ktd2692_init_flash_timeout(fled_cdev, &led_cfg); | |
379 | ktd2692_init_movie_current_max(&led_cfg); | |
380 | ||
381 | fled_cdev->ops = &flash_ops; | |
382 | ||
383 | led_cdev->max_brightness = led_cfg.max_brightness; | |
384 | led_cdev->brightness_set = ktd2692_led_brightness_set; | |
385 | led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync; | |
386 | led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH; | |
387 | ||
388 | mutex_init(&led->lock); | |
389 | INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work); | |
390 | ||
391 | platform_set_drvdata(pdev, led); | |
392 | ||
393 | ret = led_classdev_flash_register(&pdev->dev, fled_cdev); | |
394 | if (ret) { | |
395 | dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name); | |
396 | mutex_destroy(&led->lock); | |
397 | return ret; | |
398 | } | |
399 | ||
400 | ktd2692_setup(led); | |
401 | ||
402 | return 0; | |
403 | } | |
404 | ||
405 | static int ktd2692_remove(struct platform_device *pdev) | |
406 | { | |
407 | struct ktd2692_context *led = platform_get_drvdata(pdev); | |
408 | int ret; | |
409 | ||
410 | led_classdev_flash_unregister(&led->fled_cdev); | |
411 | cancel_work_sync(&led->work_brightness_set); | |
412 | ||
413 | if (led->regulator) { | |
414 | ret = regulator_disable(led->regulator); | |
415 | if (ret) | |
416 | dev_err(&pdev->dev, | |
417 | "Failed to disable supply: %d\n", ret); | |
418 | } | |
419 | ||
420 | mutex_destroy(&led->lock); | |
421 | ||
422 | return 0; | |
423 | } | |
424 | ||
425 | static const struct of_device_id ktd2692_match[] = { | |
426 | { .compatible = "kinetic,ktd2692", }, | |
427 | { /* sentinel */ }, | |
428 | }; | |
3682c7bd | 429 | MODULE_DEVICE_TABLE(of, ktd2692_match); |
b7da8c5c IK |
430 | |
431 | static struct platform_driver ktd2692_driver = { | |
432 | .driver = { | |
433 | .name = "ktd2692", | |
434 | .of_match_table = ktd2692_match, | |
435 | }, | |
436 | .probe = ktd2692_probe, | |
437 | .remove = ktd2692_remove, | |
438 | }; | |
439 | ||
440 | module_platform_driver(ktd2692_driver); | |
441 | ||
442 | MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>"); | |
443 | MODULE_DESCRIPTION("Kinetic KTD2692 LED driver"); | |
444 | MODULE_LICENSE("GPL v2"); |