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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
b7da8c5c IK |
2 | /* |
3 | * LED driver : leds-ktd2692.c | |
4 | * | |
5 | * Copyright (C) 2015 Samsung Electronics | |
6 | * Ingi Kim <ingi2.kim@samsung.com> | |
b7da8c5c IK |
7 | */ |
8 | ||
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> | |
b7da8c5c IK |
18 | |
19 | /* Value related the movie mode */ | |
20 | #define KTD2692_MOVIE_MODE_CURRENT_LEVELS 16 | |
21 | #define KTD2692_MM_TO_FL_RATIO(x) ((x) / 3) | |
967ea03c | 22 | #define KTD2692_MM_MIN_CURR_THRESHOLD_SCALE 8 |
b7da8c5c IK |
23 | |
24 | /* Value related the flash mode */ | |
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 | /* Macro for getting offset of flash timeout */ | |
30 | #define GET_TIMEOUT_OFFSET(timeout, step) ((timeout) / (step)) | |
31 | ||
32 | /* Base register address */ | |
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 | /* Set bit coding time for expresswire interface */ | |
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 | /* KTD2692 default length of name */ | |
49 | #define KTD2692_NAME_LENGTH 20 | |
50 | ||
51 | enum ktd2692_bitset { | |
52 | KTD2692_LOW = 0, | |
53 | KTD2692_HIGH, | |
54 | }; | |
55 | ||
56 | /* Movie / Flash Mode Control */ | |
57 | enum ktd2692_led_mode { | |
58 | KTD2692_MODE_DISABLE = 0, /* default */ | |
59 | KTD2692_MODE_MOVIE, | |
60 | KTD2692_MODE_FLASH, | |
61 | }; | |
62 | ||
63 | struct ktd2692_led_config_data { | |
64 | /* maximum LED current in movie mode */ | |
65 | u32 movie_max_microamp; | |
66 | /* maximum LED current in flash mode */ | |
67 | u32 flash_max_microamp; | |
68 | /* maximum flash timeout */ | |
69 | u32 flash_max_timeout; | |
70 | /* max LED brightness level */ | |
71 | enum led_brightness max_brightness; | |
72 | }; | |
73 | ||
74 | struct ktd2692_context { | |
75 | /* Related LED Flash class device */ | |
76 | struct led_classdev_flash fled_cdev; | |
77 | ||
78 | /* secures access to the device */ | |
79 | struct mutex lock; | |
80 | struct regulator *regulator; | |
b7da8c5c IK |
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 | ||
89 | static 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 | ||
95 | static 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 | ||
101 | static 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 | ||
107 | static 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 | ||
115 | static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit) | |
116 | { | |
117 | /* | |
118 | * The Low Bit(0) and High Bit(1) is based on a time detection | |
119 | * algorithm between time low and time high | |
120 | * Time_(L_LB) : Low time of the Low Bit(0) | |
121 | * Time_(H_LB) : High time of the LOW Bit(0) | |
122 | * Time_(L_HB) : Low time of the High Bit(1) | |
123 | * Time_(H_HB) : High time of the High Bit(1) | |
124 | * | |
125 | * It can be simplified to: | |
126 | * Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB) | |
127 | * High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB) | |
128 | * HIGH ___ ____ _.. _________ ___ | |
129 | * |_________| |_.. |____| |__| | |
130 | * LOW <L_LB> <H_LB> <L_HB> <H_HB> | |
131 | * [ Low Bit (0) ] [ High Bit(1) ] | |
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 | ||
146 | static 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 | ||
9d79a05e JA |
156 | static int ktd2692_led_brightness_set(struct led_classdev *led_cdev, |
157 | enum led_brightness brightness) | |
b7da8c5c | 158 | { |
9d79a05e JA |
159 | struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); |
160 | struct ktd2692_context *led = fled_cdev_to_led(fled_cdev); | |
161 | ||
b7da8c5c IK |
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); | |
b7da8c5c IK |
175 | |
176 | return 0; | |
177 | } | |
178 | ||
179 | static 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 | ||
210 | static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev, | |
211 | u32 timeout) | |
212 | { | |
213 | return 0; | |
214 | } | |
215 | ||
216 | static 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 | ||
234 | static 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 | ||
247 | static 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 | ||
967ea03c | 253 | ktd2692_expresswire_write(led, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1) |
b7da8c5c IK |
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 | ||
259 | static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev, | |
260 | struct ktd2692_led_config_data *cfg) | |
261 | { | |
8853c95e | 262 | struct device_node *np = dev_of_node(dev); |
b7da8c5c IK |
263 | struct device_node *child_node; |
264 | int ret; | |
265 | ||
8853c95e | 266 | if (!dev_of_node(dev)) |
b7da8c5c IK |
267 | return -ENXIO; |
268 | ||
5e324ebf | 269 | led->ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS); |
cbe99c53 AB |
270 | ret = PTR_ERR_OR_ZERO(led->ctrl_gpio); |
271 | if (ret) { | |
b7da8c5c IK |
272 | dev_err(dev, "cannot get ctrl-gpios %d\n", ret); |
273 | return ret; | |
274 | } | |
275 | ||
5e324ebf | 276 | led->aux_gpio = devm_gpiod_get(dev, "aux", GPIOD_ASIS); |
cbe99c53 AB |
277 | ret = PTR_ERR_OR_ZERO(led->aux_gpio); |
278 | if (ret) { | |
b7da8c5c IK |
279 | dev_err(dev, "cannot get aux-gpios %d\n", ret); |
280 | return ret; | |
281 | } | |
282 | ||
283 | led->regulator = devm_regulator_get(dev, "vin"); | |
284 | if (IS_ERR(led->regulator)) | |
285 | led->regulator = NULL; | |
286 | ||
287 | if (led->regulator) { | |
288 | ret = regulator_enable(led->regulator); | |
289 | if (ret) | |
290 | dev_err(dev, "Failed to enable supply: %d\n", ret); | |
291 | } | |
292 | ||
293 | child_node = of_get_next_available_child(np, NULL); | |
294 | if (!child_node) { | |
295 | dev_err(dev, "No DT child node found for connected LED.\n"); | |
296 | return -EINVAL; | |
297 | } | |
298 | ||
299 | led->fled_cdev.led_cdev.name = | |
300 | of_get_property(child_node, "label", NULL) ? : child_node->name; | |
301 | ||
302 | ret = of_property_read_u32(child_node, "led-max-microamp", | |
303 | &cfg->movie_max_microamp); | |
304 | if (ret) { | |
305 | dev_err(dev, "failed to parse led-max-microamp\n"); | |
77e7915b | 306 | goto err_parse_dt; |
b7da8c5c IK |
307 | } |
308 | ||
309 | ret = of_property_read_u32(child_node, "flash-max-microamp", | |
310 | &cfg->flash_max_microamp); | |
311 | if (ret) { | |
312 | dev_err(dev, "failed to parse flash-max-microamp\n"); | |
77e7915b | 313 | goto err_parse_dt; |
b7da8c5c IK |
314 | } |
315 | ||
316 | ret = of_property_read_u32(child_node, "flash-max-timeout-us", | |
317 | &cfg->flash_max_timeout); | |
77e7915b | 318 | if (ret) { |
b7da8c5c | 319 | dev_err(dev, "failed to parse flash-max-timeout-us\n"); |
77e7915b IK |
320 | goto err_parse_dt; |
321 | } | |
b7da8c5c | 322 | |
77e7915b | 323 | err_parse_dt: |
b7da8c5c IK |
324 | of_node_put(child_node); |
325 | return ret; | |
326 | } | |
327 | ||
328 | static const struct led_flash_ops flash_ops = { | |
329 | .strobe_set = ktd2692_led_flash_strobe_set, | |
330 | .timeout_set = ktd2692_led_flash_timeout_set, | |
331 | }; | |
332 | ||
333 | static int ktd2692_probe(struct platform_device *pdev) | |
334 | { | |
335 | struct ktd2692_context *led; | |
336 | struct led_classdev *led_cdev; | |
337 | struct led_classdev_flash *fled_cdev; | |
338 | struct ktd2692_led_config_data led_cfg; | |
339 | int ret; | |
340 | ||
341 | led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL); | |
342 | if (!led) | |
343 | return -ENOMEM; | |
344 | ||
345 | fled_cdev = &led->fled_cdev; | |
346 | led_cdev = &fled_cdev->led_cdev; | |
347 | ||
348 | ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg); | |
349 | if (ret) | |
350 | return ret; | |
351 | ||
352 | ktd2692_init_flash_timeout(fled_cdev, &led_cfg); | |
353 | ktd2692_init_movie_current_max(&led_cfg); | |
354 | ||
355 | fled_cdev->ops = &flash_ops; | |
356 | ||
357 | led_cdev->max_brightness = led_cfg.max_brightness; | |
9d79a05e | 358 | led_cdev->brightness_set_blocking = ktd2692_led_brightness_set; |
b7da8c5c IK |
359 | led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH; |
360 | ||
361 | mutex_init(&led->lock); | |
b7da8c5c IK |
362 | |
363 | platform_set_drvdata(pdev, led); | |
364 | ||
365 | ret = led_classdev_flash_register(&pdev->dev, fled_cdev); | |
366 | if (ret) { | |
367 | dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name); | |
368 | mutex_destroy(&led->lock); | |
369 | return ret; | |
370 | } | |
371 | ||
372 | ktd2692_setup(led); | |
373 | ||
374 | return 0; | |
375 | } | |
376 | ||
377 | static int ktd2692_remove(struct platform_device *pdev) | |
378 | { | |
379 | struct ktd2692_context *led = platform_get_drvdata(pdev); | |
380 | int ret; | |
381 | ||
382 | led_classdev_flash_unregister(&led->fled_cdev); | |
b7da8c5c IK |
383 | |
384 | if (led->regulator) { | |
385 | ret = regulator_disable(led->regulator); | |
386 | if (ret) | |
387 | dev_err(&pdev->dev, | |
388 | "Failed to disable supply: %d\n", ret); | |
389 | } | |
390 | ||
391 | mutex_destroy(&led->lock); | |
392 | ||
393 | return 0; | |
394 | } | |
395 | ||
396 | static const struct of_device_id ktd2692_match[] = { | |
397 | { .compatible = "kinetic,ktd2692", }, | |
398 | { /* sentinel */ }, | |
399 | }; | |
3682c7bd | 400 | MODULE_DEVICE_TABLE(of, ktd2692_match); |
b7da8c5c IK |
401 | |
402 | static struct platform_driver ktd2692_driver = { | |
403 | .driver = { | |
404 | .name = "ktd2692", | |
405 | .of_match_table = ktd2692_match, | |
406 | }, | |
407 | .probe = ktd2692_probe, | |
408 | .remove = ktd2692_remove, | |
409 | }; | |
410 | ||
411 | module_platform_driver(ktd2692_driver); | |
412 | ||
413 | MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>"); | |
414 | MODULE_DESCRIPTION("Kinetic KTD2692 LED driver"); | |
415 | MODULE_LICENSE("GPL v2"); |