root/drivers/leds/leds-mt6323.c

DEFINITIONS

1. mt6323_led_hw_brightness
2. mt6323_led_hw_off
3. mt6323_get_led_hw_brightness
4. mt6323_led_hw_on
5. mt6323_led_set_blink
6. mt6323_led_set_brightness
7. mt6323_led_set_dt_default
8. mt6323_led_probe
9. mt6323_led_remove

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * LED driver for Mediatek MT6323 PMIC
   4  *
   5  * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
   6  */
   7 #include <linux/kernel.h>
   8 #include <linux/leds.h>
   9 #include <linux/mfd/mt6323/registers.h>
  10 #include <linux/mfd/mt6397/core.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/regmap.h>
  15 
  16 /*
  17  * Register field for MT6323_TOP_CKPDN0 to enable
  18  * 32K clock common for LED device.
  19  */
  20 #define MT6323_RG_DRV_32K_CK_PDN        BIT(11)
  21 #define MT6323_RG_DRV_32K_CK_PDN_MASK   BIT(11)
  22 
  23 /*
  24  * Register field for MT6323_TOP_CKPDN2 to enable
  25  * individual clock for LED device.
  26  */
  27 #define MT6323_RG_ISINK_CK_PDN(i)       BIT(i)
  28 #define MT6323_RG_ISINK_CK_PDN_MASK(i)  BIT(i)
  29 
  30 /*
  31  * Register field for MT6323_TOP_CKCON1 to select
  32  * clock source.
  33  */
  34 #define MT6323_RG_ISINK_CK_SEL_MASK(i)  (BIT(10) << (i))
  35 
  36 /*
  37  * Register for MT6323_ISINK_CON0 to setup the
  38  * duty cycle of the blink.
  39  */
  40 #define MT6323_ISINK_CON0(i)            (MT6323_ISINK0_CON0 + 0x8 * (i))
  41 #define MT6323_ISINK_DIM_DUTY_MASK      (0x1f << 8)
  42 #define MT6323_ISINK_DIM_DUTY(i)        (((i) << 8) & \
  43                                         MT6323_ISINK_DIM_DUTY_MASK)
  44 
  45 /* Register to setup the period of the blink. */
  46 #define MT6323_ISINK_CON1(i)            (MT6323_ISINK0_CON1 + 0x8 * (i))
  47 #define MT6323_ISINK_DIM_FSEL_MASK      (0xffff)
  48 #define MT6323_ISINK_DIM_FSEL(i)        ((i) & MT6323_ISINK_DIM_FSEL_MASK)
  49 
  50 /* Register to control the brightness. */
  51 #define MT6323_ISINK_CON2(i)            (MT6323_ISINK0_CON2 + 0x8 * (i))
  52 #define MT6323_ISINK_CH_STEP_SHIFT      12
  53 #define MT6323_ISINK_CH_STEP_MASK       (0x7 << 12)
  54 #define MT6323_ISINK_CH_STEP(i)         (((i) << 12) & \
  55                                         MT6323_ISINK_CH_STEP_MASK)
  56 #define MT6323_ISINK_SFSTR0_TC_MASK     (0x3 << 1)
  57 #define MT6323_ISINK_SFSTR0_TC(i)       (((i) << 1) & \
  58                                         MT6323_ISINK_SFSTR0_TC_MASK)
  59 #define MT6323_ISINK_SFSTR0_EN_MASK     BIT(0)
  60 #define MT6323_ISINK_SFSTR0_EN          BIT(0)
  61 
  62 /* Register to LED channel enablement. */
  63 #define MT6323_ISINK_CH_EN_MASK(i)      BIT(i)
  64 #define MT6323_ISINK_CH_EN(i)           BIT(i)
  65 
  66 #define MT6323_MAX_PERIOD               10000
  67 #define MT6323_MAX_LEDS                 4
  68 #define MT6323_MAX_BRIGHTNESS           6
  69 #define MT6323_UNIT_DUTY                3125
  70 #define MT6323_CAL_HW_DUTY(o, p)        DIV_ROUND_CLOSEST((o) * 100000ul,\
  71                                         (p) * MT6323_UNIT_DUTY)
  72 
  73 struct mt6323_leds;
  74 
  75 /**
  76  * struct mt6323_led - state container for the LED device
  77  * @id:                 the identifier in MT6323 LED device
  78  * @parent:             the pointer to MT6323 LED controller
  79  * @cdev:               LED class device for this LED device
  80  * @current_brightness: current state of the LED device
  81  */
  82 struct mt6323_led {
  83         int                     id;
  84         struct mt6323_leds      *parent;
  85         struct led_classdev     cdev;
  86         enum led_brightness     current_brightness;
  87 };
  88 
  89 /**
  90  * struct mt6323_leds - state container for holding LED controller
  91  *                      of the driver
  92  * @dev:                the device pointer
  93  * @hw:                 the underlying hardware providing shared
  94  *                      bus for the register operations
  95  * @lock:               the lock among process context
  96  * @led:                the array that contains the state of individual
  97  *                      LED device
  98  */
  99 struct mt6323_leds {
 100         struct device           *dev;
 101         struct mt6397_chip      *hw;
 102         /* protect among process context */
 103         struct mutex            lock;
 104         struct mt6323_led       *led[MT6323_MAX_LEDS];
 105 };
 106 
 107 static int mt6323_led_hw_brightness(struct led_classdev *cdev,
 108                                     enum led_brightness brightness)
 109 {
 110         struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 111         struct mt6323_leds *leds = led->parent;
 112         struct regmap *regmap = leds->hw->regmap;
 113         u32 con2_mask = 0, con2_val = 0;
 114         int ret;
 115 
 116         /*
 117          * Setup current output for the corresponding
 118          * brightness level.
 119          */
 120         con2_mask |= MT6323_ISINK_CH_STEP_MASK |
 121                      MT6323_ISINK_SFSTR0_TC_MASK |
 122                      MT6323_ISINK_SFSTR0_EN_MASK;
 123         con2_val |=  MT6323_ISINK_CH_STEP(brightness - 1) |
 124                      MT6323_ISINK_SFSTR0_TC(2) |
 125                      MT6323_ISINK_SFSTR0_EN;
 126 
 127         ret = regmap_update_bits(regmap, MT6323_ISINK_CON2(led->id),
 128                                  con2_mask, con2_val);
 129         return ret;
 130 }
 131 
 132 static int mt6323_led_hw_off(struct led_classdev *cdev)
 133 {
 134         struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 135         struct mt6323_leds *leds = led->parent;
 136         struct regmap *regmap = leds->hw->regmap;
 137         unsigned int status;
 138         int ret;
 139 
 140         status = MT6323_ISINK_CH_EN(led->id);
 141         ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
 142                                  MT6323_ISINK_CH_EN_MASK(led->id), ~status);
 143         if (ret < 0)
 144                 return ret;
 145 
 146         usleep_range(100, 300);
 147         ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
 148                                  MT6323_RG_ISINK_CK_PDN_MASK(led->id),
 149                                  MT6323_RG_ISINK_CK_PDN(led->id));
 150         if (ret < 0)
 151                 return ret;
 152 
 153         return 0;
 154 }
 155 
 156 static enum led_brightness
 157 mt6323_get_led_hw_brightness(struct led_classdev *cdev)
 158 {
 159         struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 160         struct mt6323_leds *leds = led->parent;
 161         struct regmap *regmap = leds->hw->regmap;
 162         unsigned int status;
 163         int ret;
 164 
 165         ret = regmap_read(regmap, MT6323_TOP_CKPDN2, &status);
 166         if (ret < 0)
 167                 return ret;
 168 
 169         if (status & MT6323_RG_ISINK_CK_PDN_MASK(led->id))
 170                 return 0;
 171 
 172         ret = regmap_read(regmap, MT6323_ISINK_EN_CTRL, &status);
 173         if (ret < 0)
 174                 return ret;
 175 
 176         if (!(status & MT6323_ISINK_CH_EN(led->id)))
 177                 return 0;
 178 
 179         ret = regmap_read(regmap, MT6323_ISINK_CON2(led->id), &status);
 180         if (ret < 0)
 181                 return ret;
 182 
 183         return  ((status & MT6323_ISINK_CH_STEP_MASK)
 184                   >> MT6323_ISINK_CH_STEP_SHIFT) + 1;
 185 }
 186 
 187 static int mt6323_led_hw_on(struct led_classdev *cdev,
 188                             enum led_brightness brightness)
 189 {
 190         struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 191         struct mt6323_leds *leds = led->parent;
 192         struct regmap *regmap = leds->hw->regmap;
 193         unsigned int status;
 194         int ret;
 195 
 196         /*
 197          * Setup required clock source, enable the corresponding
 198          * clock and channel and let work with continuous blink as
 199          * the default.
 200          */
 201         ret = regmap_update_bits(regmap, MT6323_TOP_CKCON1,
 202                                  MT6323_RG_ISINK_CK_SEL_MASK(led->id), 0);
 203         if (ret < 0)
 204                 return ret;
 205 
 206         status = MT6323_RG_ISINK_CK_PDN(led->id);
 207         ret = regmap_update_bits(regmap, MT6323_TOP_CKPDN2,
 208                                  MT6323_RG_ISINK_CK_PDN_MASK(led->id),
 209                                  ~status);
 210         if (ret < 0)
 211                 return ret;
 212 
 213         usleep_range(100, 300);
 214 
 215         ret = regmap_update_bits(regmap, MT6323_ISINK_EN_CTRL,
 216                                  MT6323_ISINK_CH_EN_MASK(led->id),
 217                                  MT6323_ISINK_CH_EN(led->id));
 218         if (ret < 0)
 219                 return ret;
 220 
 221         ret = mt6323_led_hw_brightness(cdev, brightness);
 222         if (ret < 0)
 223                 return ret;
 224 
 225         ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
 226                                  MT6323_ISINK_DIM_DUTY_MASK,
 227                                  MT6323_ISINK_DIM_DUTY(31));
 228         if (ret < 0)
 229                 return ret;
 230 
 231         ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
 232                                  MT6323_ISINK_DIM_FSEL_MASK,
 233                                  MT6323_ISINK_DIM_FSEL(1000));
 234         if (ret < 0)
 235                 return ret;
 236 
 237         return 0;
 238 }
 239 
 240 static int mt6323_led_set_blink(struct led_classdev *cdev,
 241                                 unsigned long *delay_on,
 242                                 unsigned long *delay_off)
 243 {
 244         struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 245         struct mt6323_leds *leds = led->parent;
 246         struct regmap *regmap = leds->hw->regmap;
 247         unsigned long period;
 248         u8 duty_hw;
 249         int ret;
 250 
 251         /*
 252          * Units are in ms, if over the hardware able
 253          * to support, fallback into software blink
 254          */
 255         period = *delay_on + *delay_off;
 256 
 257         if (period > MT6323_MAX_PERIOD)
 258                 return -EINVAL;
 259 
 260         /*
 261          * LED subsystem requires a default user
 262          * friendly blink pattern for the LED so using
 263          * 1Hz duty cycle 50% here if without specific
 264          * value delay_on and delay off being assigned.
 265          */
 266         if (!*delay_on && !*delay_off) {
 267                 *delay_on = 500;
 268                 *delay_off = 500;
 269         }
 270 
 271         /*
 272          * Calculate duty_hw based on the percentage of period during
 273          * which the led is ON.
 274          */
 275         duty_hw = MT6323_CAL_HW_DUTY(*delay_on, period);
 276 
 277         /* hardware doesn't support zero duty cycle. */
 278         if (!duty_hw)
 279                 return -EINVAL;
 280 
 281         mutex_lock(&leds->lock);
 282         /*
 283          * Set max_brightness as the software blink behavior
 284          * when no blink brightness.
 285          */
 286         if (!led->current_brightness) {
 287                 ret = mt6323_led_hw_on(cdev, cdev->max_brightness);
 288                 if (ret < 0)
 289                         goto out;
 290                 led->current_brightness = cdev->max_brightness;
 291         }
 292 
 293         ret = regmap_update_bits(regmap, MT6323_ISINK_CON0(led->id),
 294                                  MT6323_ISINK_DIM_DUTY_MASK,
 295                                  MT6323_ISINK_DIM_DUTY(duty_hw - 1));
 296         if (ret < 0)
 297                 goto out;
 298 
 299         ret = regmap_update_bits(regmap, MT6323_ISINK_CON1(led->id),
 300                                  MT6323_ISINK_DIM_FSEL_MASK,
 301                                  MT6323_ISINK_DIM_FSEL(period - 1));
 302 out:
 303         mutex_unlock(&leds->lock);
 304 
 305         return ret;
 306 }
 307 
 308 static int mt6323_led_set_brightness(struct led_classdev *cdev,
 309                                      enum led_brightness brightness)
 310 {
 311         struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 312         struct mt6323_leds *leds = led->parent;
 313         int ret;
 314 
 315         mutex_lock(&leds->lock);
 316 
 317         if (!led->current_brightness && brightness) {
 318                 ret = mt6323_led_hw_on(cdev, brightness);
 319                 if (ret < 0)
 320                         goto out;
 321         } else if (brightness) {
 322                 ret = mt6323_led_hw_brightness(cdev, brightness);
 323                 if (ret < 0)
 324                         goto out;
 325         } else {
 326                 ret = mt6323_led_hw_off(cdev);
 327                 if (ret < 0)
 328                         goto out;
 329         }
 330 
 331         led->current_brightness = brightness;
 332 out:
 333         mutex_unlock(&leds->lock);
 334 
 335         return ret;
 336 }
 337 
 338 static int mt6323_led_set_dt_default(struct led_classdev *cdev,
 339                                      struct device_node *np)
 340 {
 341         struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
 342         const char *state;
 343         int ret = 0;
 344 
 345         led->cdev.name = of_get_property(np, "label", NULL) ? : np->name;
 346         led->cdev.default_trigger = of_get_property(np,
 347                                                     "linux,default-trigger",
 348                                                     NULL);
 349 
 350         state = of_get_property(np, "default-state", NULL);
 351         if (state) {
 352                 if (!strcmp(state, "keep")) {
 353                         ret = mt6323_get_led_hw_brightness(cdev);
 354                         if (ret < 0)
 355                                 return ret;
 356                         led->current_brightness = ret;
 357                         ret = 0;
 358                 } else if (!strcmp(state, "on")) {
 359                         ret =
 360                         mt6323_led_set_brightness(cdev, cdev->max_brightness);
 361                 } else  {
 362                         ret = mt6323_led_set_brightness(cdev, LED_OFF);
 363                 }
 364         }
 365 
 366         return ret;
 367 }
 368 
 369 static int mt6323_led_probe(struct platform_device *pdev)
 370 {
 371         struct device *dev = &pdev->dev;
 372         struct device_node *np = pdev->dev.of_node;
 373         struct device_node *child;
 374         struct mt6397_chip *hw = dev_get_drvdata(pdev->dev.parent);
 375         struct mt6323_leds *leds;
 376         struct mt6323_led *led;
 377         int ret;
 378         unsigned int status;
 379         u32 reg;
 380 
 381         leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);
 382         if (!leds)
 383                 return -ENOMEM;
 384 
 385         platform_set_drvdata(pdev, leds);
 386         leds->dev = dev;
 387 
 388         /*
 389          * leds->hw points to the underlying bus for the register
 390          * controlled.
 391          */
 392         leds->hw = hw;
 393         mutex_init(&leds->lock);
 394 
 395         status = MT6323_RG_DRV_32K_CK_PDN;
 396         ret = regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
 397                                  MT6323_RG_DRV_32K_CK_PDN_MASK, ~status);
 398         if (ret < 0) {
 399                 dev_err(leds->dev,
 400                         "Failed to update MT6323_TOP_CKPDN0 Register\n");
 401                 return ret;
 402         }
 403 
 404         for_each_available_child_of_node(np, child) {
 405                 ret = of_property_read_u32(child, "reg", &reg);
 406                 if (ret) {
 407                         dev_err(dev, "Failed to read led 'reg' property\n");
 408                         goto put_child_node;
 409                 }
 410 
 411                 if (reg >= MT6323_MAX_LEDS || leds->led[reg]) {
 412                         dev_err(dev, "Invalid led reg %u\n", reg);
 413                         ret = -EINVAL;
 414                         goto put_child_node;
 415                 }
 416 
 417                 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
 418                 if (!led) {
 419                         ret = -ENOMEM;
 420                         goto put_child_node;
 421                 }
 422 
 423                 leds->led[reg] = led;
 424                 leds->led[reg]->id = reg;
 425                 leds->led[reg]->cdev.max_brightness = MT6323_MAX_BRIGHTNESS;
 426                 leds->led[reg]->cdev.brightness_set_blocking =
 427                                         mt6323_led_set_brightness;
 428                 leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
 429                 leds->led[reg]->cdev.brightness_get =
 430                                         mt6323_get_led_hw_brightness;
 431                 leds->led[reg]->parent = leds;
 432 
 433                 ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
 434                 if (ret < 0) {
 435                         dev_err(leds->dev,
 436                                 "Failed to LED set default from devicetree\n");
 437                         goto put_child_node;
 438                 }
 439 
 440                 ret = devm_led_classdev_register(dev, &leds->led[reg]->cdev);
 441                 if (ret) {
 442                         dev_err(&pdev->dev, "Failed to register LED: %d\n",
 443                                 ret);
 444                         goto put_child_node;
 445                 }
 446                 leds->led[reg]->cdev.dev->of_node = child;
 447         }
 448 
 449         return 0;
 450 
 451 put_child_node:
 452         of_node_put(child);
 453         return ret;
 454 }
 455 
 456 static int mt6323_led_remove(struct platform_device *pdev)
 457 {
 458         struct mt6323_leds *leds = platform_get_drvdata(pdev);
 459         int i;
 460 
 461         /* Turn the LEDs off on driver removal. */
 462         for (i = 0 ; leds->led[i] ; i++)
 463                 mt6323_led_hw_off(&leds->led[i]->cdev);
 464 
 465         regmap_update_bits(leds->hw->regmap, MT6323_TOP_CKPDN0,
 466                            MT6323_RG_DRV_32K_CK_PDN_MASK,
 467                            MT6323_RG_DRV_32K_CK_PDN);
 468 
 469         mutex_destroy(&leds->lock);
 470 
 471         return 0;
 472 }
 473 
 474 static const struct of_device_id mt6323_led_dt_match[] = {
 475         { .compatible = "mediatek,mt6323-led" },
 476         {},
 477 };
 478 MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);
 479 
 480 static struct platform_driver mt6323_led_driver = {
 481         .probe          = mt6323_led_probe,
 482         .remove         = mt6323_led_remove,
 483         .driver         = {
 484                 .name   = "mt6323-led",
 485                 .of_match_table = mt6323_led_dt_match,
 486         },
 487 };
 488 
 489 module_platform_driver(mt6323_led_driver);
 490 
 491 MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC");
 492 MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
 493 MODULE_LICENSE("GPL");