1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * LED driver : leds-ktd2692.c 4 * 5 * Copyright (C) 2015 Samsung Electronics 6 * Ingi Kim <ingi2.kim@samsung.com> 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> 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) 22 #define KTD2692_MM_MIN_CURR_THRESHOLD_SCALE 8 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; 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 } 155 156 static 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 } 178 179 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); 252 253 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 } 258 259 static 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 } 269 270 static 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 (!np) 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 } 339 340 err_parse_dt: 341 of_node_put(child_node); 342 return ret; 343 } 344 345 static const struct led_flash_ops flash_ops = { 346 .strobe_set = ktd2692_led_flash_strobe_set, 347 .timeout_set = ktd2692_led_flash_timeout_set, 348 }; 349 350 static 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 } 393 394 static 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 } 404 405 static const struct of_device_id ktd2692_match[] = { 406 { .compatible = "kinetic,ktd2692", }, 407 { /* sentinel */ }, 408 }; 409 MODULE_DEVICE_TABLE(of, ktd2692_match); 410 411 static 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 }; 419 420 module_platform_driver(ktd2692_driver); 421 422 MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>"); 423 MODULE_DESCRIPTION("Kinetic KTD2692 LED driver"); 424 MODULE_LICENSE("GPL v2"); 425