drivers/leds/leds-cht-wcove.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for LEDs connected to the Intel Cherry Trail Whiskey Cove PMIC
   4  *
   5  * Copyright 2019 Yauhen Kharuzhy <jekhor@gmail.com>
   6  * Copyright 2023 Hans de Goede <hansg@kernel.org>
   7  *
   8  * Register info comes from the Lenovo Yoga Book Android opensource code
   9  * available from Lenovo. File lenovo_yb1_x90f_l_osc_201803.7z path in the 7z:
  10  * YB1_source_code/kernel/cht/drivers/misc/charger_gp_led.c
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/leds.h>
  15 #include <linux/mfd/intel_soc_pmic.h>
  16 #include <linux/module.h>
  17 #include <linux/mod_devicetable.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/regmap.h>
  20 #include <linux/suspend.h>
  21
  22 #define CHT_WC_LED1_CTRL                0x5e1f
  23 #define CHT_WC_LED1_FSM                 0x5e20
  24 #define CHT_WC_LED1_PWM                 0x5e21
  25
  26 #define CHT_WC_LED2_CTRL                0x4fdf
  27 #define CHT_WC_LED2_FSM                 0x4fe0
  28 #define CHT_WC_LED2_PWM                 0x4fe1
  29
  30 #define CHT_WC_LED1_SWCTL               BIT(0)          /* HW or SW control of charging led */
  31 #define CHT_WC_LED1_ON                  BIT(1)
  32
  33 #define CHT_WC_LED2_ON                  BIT(0)
  34 #define CHT_WC_LED_I_MA2_5              (2 << 2)        /* LED current limit */
  35 #define CHT_WC_LED_I_MASK               GENMASK(3, 2)   /* LED current limit mask */
  36
  37 #define CHT_WC_LED_F_1_4_HZ             (0 << 4)
  38 #define CHT_WC_LED_F_1_2_HZ             (1 << 4)
  39 #define CHT_WC_LED_F_1_HZ               (2 << 4)
  40 #define CHT_WC_LED_F_2_HZ               (3 << 4)
  41 #define CHT_WC_LED_F_MASK               GENMASK(5, 4)
  42
  43 #define CHT_WC_LED_EFF_OFF              (0 << 1)
  44 #define CHT_WC_LED_EFF_ON               (1 << 1)
  45 #define CHT_WC_LED_EFF_BLINKING         (2 << 1)
  46 #define CHT_WC_LED_EFF_BREATHING        (3 << 1)
  47 #define CHT_WC_LED_EFF_MASK             GENMASK(2, 1)
  48
  49 #define CHT_WC_LED_COUNT                2
  50
  51 struct cht_wc_led_regs {
  52         /* Register addresses */
  53         u16 ctrl;
  54         u16 fsm;
  55         u16 pwm;
  56         /* Mask + values for turning the LED on/off */
  57         u8 on_off_mask;
  58         u8 on_val;
  59         u8 off_val;
  60 };
  61
  62 struct cht_wc_led_saved_regs {
  63         unsigned int ctrl;
  64         unsigned int fsm;
  65         unsigned int pwm;
  66 };
  67
  68 struct cht_wc_led {
  69         struct led_classdev cdev;
  70         const struct cht_wc_led_regs *regs;
  71         struct regmap *regmap;
  72         struct mutex mutex;
  73         struct cht_wc_led_saved_regs saved_regs;
  74 };
  75
  76 struct cht_wc_leds {
  77         struct cht_wc_led leds[CHT_WC_LED_COUNT];
  78         /* Saved LED1 initial register values */
  79         struct cht_wc_led_saved_regs led1_initial_regs;
  80 };
  81
  82 static const struct cht_wc_led_regs cht_wc_led_regs[CHT_WC_LED_COUNT] = {
  83         {
  84                 .ctrl           = CHT_WC_LED1_CTRL,
  85                 .fsm            = CHT_WC_LED1_FSM,
  86                 .pwm            = CHT_WC_LED1_PWM,
  87                 .on_off_mask    = CHT_WC_LED1_SWCTL | CHT_WC_LED1_ON,
  88                 .on_val         = CHT_WC_LED1_SWCTL | CHT_WC_LED1_ON,
  89                 .off_val        = CHT_WC_LED1_SWCTL,
  90         },
  91         {
  92                 .ctrl           = CHT_WC_LED2_CTRL,
  93                 .fsm            = CHT_WC_LED2_FSM,
  94                 .pwm            = CHT_WC_LED2_PWM,
  95                 .on_off_mask    = CHT_WC_LED2_ON,
  96                 .on_val         = CHT_WC_LED2_ON,
  97                 .off_val        = 0,
  98         },
  99 };
 100
 101 static const char * const cht_wc_leds_names[CHT_WC_LED_COUNT] = {
 102         "platform::" LED_FUNCTION_CHARGING,
 103         "platform::" LED_FUNCTION_INDICATOR,
 104 };
 105
 106 static int cht_wc_leds_brightness_set(struct led_classdev *cdev,
 107                                       enum led_brightness value)
 108 {
 109         struct cht_wc_led *led = container_of(cdev, struct cht_wc_led, cdev);
 110         int ret;
 111
 112         mutex_lock(&led->mutex);
 113
 114         if (!value) {
 115                 ret = regmap_update_bits(led->regmap, led->regs->ctrl,
 116                                          led->regs->on_off_mask, led->regs->off_val);
 117                 if (ret < 0) {
 118                         dev_err(cdev->dev, "Failed to turn off: %d\n", ret);
 119                         goto out;
 120                 }
 121
 122                 /* Disable HW blinking */
 123                 ret = regmap_update_bits(led->regmap, led->regs->fsm,
 124                                          CHT_WC_LED_EFF_MASK, CHT_WC_LED_EFF_ON);
 125                 if (ret < 0)
 126                         dev_err(cdev->dev, "Failed to update LED FSM reg: %d\n", ret);
 127         } else {
 128                 ret = regmap_write(led->regmap, led->regs->pwm, value);
 129                 if (ret < 0) {
 130                         dev_err(cdev->dev, "Failed to set brightness: %d\n", ret);
 131                         goto out;
 132                 }
 133
 134                 ret = regmap_update_bits(led->regmap, led->regs->ctrl,
 135                                          led->regs->on_off_mask, led->regs->on_val);
 136                 if (ret < 0)
 137                         dev_err(cdev->dev, "Failed to turn on: %d\n", ret);
 138         }
 139 out:
 140         mutex_unlock(&led->mutex);
 141         return ret;
 142 }
 143
 144 static enum led_brightness cht_wc_leds_brightness_get(struct led_classdev *cdev)
 145 {
 146         struct cht_wc_led *led = container_of(cdev, struct cht_wc_led, cdev);
 147         unsigned int val;
 148         int ret;
 149
 150         mutex_lock(&led->mutex);
 151
 152         ret = regmap_read(led->regmap, led->regs->ctrl, &val);
 153         if (ret < 0) {
 154                 dev_err(cdev->dev, "Failed to read LED CTRL reg: %d\n", ret);
 155                 ret = 0;
 156                 goto done;
 157         }
 158
 159         val &= led->regs->on_off_mask;
 160         if (val != led->regs->on_val) {
 161                 ret = 0;
 162                 goto done;
 163         }
 164
 165         ret = regmap_read(led->regmap, led->regs->pwm, &val);
 166         if (ret < 0) {
 167                 dev_err(cdev->dev, "Failed to read LED PWM reg: %d\n", ret);
 168                 ret = 0;
 169                 goto done;
 170         }
 171
 172         ret = val;
 173 done:
 174         mutex_unlock(&led->mutex);
 175
 176         return ret;
 177 }
 178
 179 /* Return blinking period for given CTRL reg value */
 180 static unsigned long cht_wc_leds_get_period(int ctrl)
 181 {
 182         ctrl &= CHT_WC_LED_F_MASK;
 183
 184         switch (ctrl) {
 185         case CHT_WC_LED_F_1_4_HZ:
 186                 return 1000 * 4;
 187         case CHT_WC_LED_F_1_2_HZ:
 188                 return 1000 * 2;
 189         case CHT_WC_LED_F_1_HZ:
 190                 return 1000;
 191         case CHT_WC_LED_F_2_HZ:
 192                 return 1000 / 2;
 193         }
 194
 195         return 0;
 196 }
 197
 198 /*
 199  * Find suitable hardware blink mode for given period.
 200  * period < 750 ms - select 2 HZ
 201  * 750 ms <= period < 1500 ms - select 1 HZ
 202  * 1500 ms <= period < 3000 ms - select 1/2 HZ
 203  * 3000 ms <= period < 5000 ms - select 1/4 HZ
 204  * 5000 ms <= period - return -1
 205  */
 206 static int cht_wc_leds_find_freq(unsigned long period)
 207 {
 208         if (period < 750)
 209                 return CHT_WC_LED_F_2_HZ;
 210         else if (period < 1500)
 211                 return CHT_WC_LED_F_1_HZ;
 212         else if (period < 3000)
 213                 return CHT_WC_LED_F_1_2_HZ;
 214         else if (period < 5000)
 215                 return CHT_WC_LED_F_1_4_HZ;
 216         else
 217                 return -1;
 218 }
 219
 220 static int cht_wc_leds_set_effect(struct led_classdev *cdev,
 221                                   unsigned long *delay_on,
 222                                   unsigned long *delay_off,
 223                                   u8 effect)
 224 {
 225         struct cht_wc_led *led = container_of(cdev, struct cht_wc_led, cdev);
 226         int ctrl, ret;
 227
 228         mutex_lock(&led->mutex);
 229
 230         /* Blink with 1 Hz as default if nothing specified */
 231         if (!*delay_on && !*delay_off)
 232                 *delay_on = *delay_off = 500;
 233
 234         ctrl = cht_wc_leds_find_freq(*delay_on + *delay_off);
 235         if (ctrl < 0) {
 236                 /* Disable HW blinking */
 237                 ret = regmap_update_bits(led->regmap, led->regs->fsm,
 238                                          CHT_WC_LED_EFF_MASK, CHT_WC_LED_EFF_ON);
 239                 if (ret < 0)
 240                         dev_err(cdev->dev, "Failed to update LED FSM reg: %d\n", ret);
 241
 242                 /* Fallback to software timer */
 243                 *delay_on = *delay_off = 0;
 244                 ret = -EINVAL;
 245                 goto done;
 246         }
 247
 248         ret = regmap_update_bits(led->regmap, led->regs->fsm,
 249                                  CHT_WC_LED_EFF_MASK, effect);
 250         if (ret < 0)
 251                 dev_err(cdev->dev, "Failed to update LED FSM reg: %d\n", ret);
 252
 253         /* Set the frequency and make sure the LED is on */
 254         ret = regmap_update_bits(led->regmap, led->regs->ctrl,
 255                                  CHT_WC_LED_F_MASK | led->regs->on_off_mask,
 256                                  ctrl | led->regs->on_val);
 257         if (ret < 0)
 258                 dev_err(cdev->dev, "Failed to update LED CTRL reg: %d\n", ret);
 259
 260         *delay_off = *delay_on = cht_wc_leds_get_period(ctrl) / 2;
 261
 262 done:
 263         mutex_unlock(&led->mutex);
 264
 265         return ret;
 266 }
 267
 268 static int cht_wc_leds_blink_set(struct led_classdev *cdev,
 269                                  unsigned long *delay_on,
 270                                  unsigned long *delay_off)
 271 {
 272         u8 effect = CHT_WC_LED_EFF_BLINKING;
 273
 274         /*
 275          * The desired default behavior of LED1 / the charge LED is breathing
 276          * while charging and on/solid when full. Since triggers cannot select
 277          * breathing, blink_set() gets called when charging. Use slow breathing
 278          * when the default "charging-blink-full-solid" trigger is used to
 279          * achieve the desired default behavior.
 280          */
 281         if (cdev->flags & LED_INIT_DEFAULT_TRIGGER) {
 282                 *delay_on = *delay_off = 1000;
 283                 effect = CHT_WC_LED_EFF_BREATHING;
 284         }
 285
 286         return cht_wc_leds_set_effect(cdev, delay_on, delay_off, effect);
 287 }
 288
 289 static int cht_wc_leds_pattern_set(struct led_classdev *cdev,
 290                                    struct led_pattern *pattern,
 291                                    u32 len, int repeat)
 292 {
 293         unsigned long delay_off, delay_on;
 294
 295         if (repeat > 0 || len != 2 ||
 296             pattern[0].brightness != 0 || pattern[1].brightness != 1 ||
 297             pattern[0].delta_t != pattern[1].delta_t ||
 298             (pattern[0].delta_t != 250 && pattern[0].delta_t != 500 &&
 299              pattern[0].delta_t != 1000 && pattern[0].delta_t != 2000))
 300                 return -EINVAL;
 301
 302         delay_off = pattern[0].delta_t;
 303         delay_on  = pattern[1].delta_t;
 304
 305         return cht_wc_leds_set_effect(cdev, &delay_on, &delay_off, CHT_WC_LED_EFF_BREATHING);
 306 }
 307
 308 static int cht_wc_leds_pattern_clear(struct led_classdev *cdev)
 309 {
 310         return cht_wc_leds_brightness_set(cdev, 0);
 311 }
 312
 313 static int cht_wc_led_save_regs(struct cht_wc_led *led,
 314                                 struct cht_wc_led_saved_regs *saved_regs)
 315 {
 316         int ret;
 317
 318         ret = regmap_read(led->regmap, led->regs->ctrl, &saved_regs->ctrl);
 319         if (ret < 0)
 320                 return ret;
 321
 322         ret = regmap_read(led->regmap, led->regs->fsm, &saved_regs->fsm);
 323         if (ret < 0)
 324                 return ret;
 325
 326         return regmap_read(led->regmap, led->regs->pwm, &saved_regs->pwm);
 327 }
 328
 329 static void cht_wc_led_restore_regs(struct cht_wc_led *led,
 330                                     const struct cht_wc_led_saved_regs *saved_regs)
 331 {
 332         regmap_write(led->regmap, led->regs->ctrl, saved_regs->ctrl);
 333         regmap_write(led->regmap, led->regs->fsm, saved_regs->fsm);
 334         regmap_write(led->regmap, led->regs->pwm, saved_regs->pwm);
 335 }
 336
 337 static int cht_wc_leds_probe(struct platform_device *pdev)
 338 {
 339         struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
 340         struct cht_wc_leds *leds;
 341         int ret;
 342         int i;
 343
 344         /*
 345          * On the Lenovo Yoga Tab 3 the LED1 driver output is actually
 346          * connected to a haptic feedback motor rather then a LED.
 347          * So do not register a LED classdev there (LED2 is unused).
 348          */
 349         if (pmic->cht_wc_model == INTEL_CHT_WC_LENOVO_YT3_X90)
 350                 return -ENODEV;
 351
 352         leds = devm_kzalloc(&pdev->dev, sizeof(*leds), GFP_KERNEL);
 353         if (!leds)
 354                 return -ENOMEM;
 355
 356         /*
 357          * LED1 might be in hw-controlled mode when this driver gets loaded; and
 358          * since the PMIC is always powered by the battery any changes made are
 359          * permanent. Save LED1 regs to restore them on remove() or shutdown().
 360          */
 361         leds->leds[0].regs = &cht_wc_led_regs[0];
 362         leds->leds[0].regmap = pmic->regmap;
 363         ret = cht_wc_led_save_regs(&leds->leds[0], &leds->led1_initial_regs);
 364         if (ret < 0)
 365                 return ret;
 366
 367         /* Set LED1 default trigger based on machine model */
 368         switch (pmic->cht_wc_model) {
 369         case INTEL_CHT_WC_GPD_WIN_POCKET:
 370                 leds->leds[0].cdev.default_trigger = "max170xx_battery-charging-blink-full-solid";
 371                 break;
 372         case INTEL_CHT_WC_XIAOMI_MIPAD2:
 373                 leds->leds[0].cdev.default_trigger = "bq27520-0-charging-blink-full-solid";
 374                 break;
 375         case INTEL_CHT_WC_LENOVO_YOGABOOK1:
 376                 leds->leds[0].cdev.default_trigger = "bq27542-0-charging-blink-full-solid";
 377                 break;
 378         default:
 379                 dev_warn(&pdev->dev, "Unknown model, no default charging trigger\n");
 380                 break;
 381         }
 382
 383         for (i = 0; i < CHT_WC_LED_COUNT; i++) {
 384                 struct cht_wc_led *led = &leds->leds[i];
 385
 386                 led->regs = &cht_wc_led_regs[i];
 387                 led->regmap = pmic->regmap;
 388                 mutex_init(&led->mutex);
 389                 led->cdev.name = cht_wc_leds_names[i];
 390                 led->cdev.brightness_set_blocking = cht_wc_leds_brightness_set;
 391                 led->cdev.brightness_get = cht_wc_leds_brightness_get;
 392                 led->cdev.blink_set = cht_wc_leds_blink_set;
 393                 led->cdev.pattern_set = cht_wc_leds_pattern_set;
 394                 led->cdev.pattern_clear = cht_wc_leds_pattern_clear;
 395                 led->cdev.max_brightness = 255;
 396
 397                 ret = led_classdev_register(&pdev->dev, &led->cdev);
 398                 if (ret < 0)
 399                         return ret;
 400         }
 401
 402         platform_set_drvdata(pdev, leds);
 403         return 0;
 404 }
 405
 406 static void cht_wc_leds_remove(struct platform_device *pdev)
 407 {
 408         struct cht_wc_leds *leds = platform_get_drvdata(pdev);
 409         int i;
 410
 411         for (i = 0; i < CHT_WC_LED_COUNT; i++)
 412                 led_classdev_unregister(&leds->leds[i].cdev);
 413
 414         /* Restore LED1 regs if hw-control was active else leave LED1 off */
 415         if (!(leds->led1_initial_regs.ctrl & CHT_WC_LED1_SWCTL))
 416                 cht_wc_led_restore_regs(&leds->leds[0], &leds->led1_initial_regs);
 417 }
 418
 419 static void cht_wc_leds_disable(struct platform_device *pdev)
 420 {
 421         struct cht_wc_leds *leds = platform_get_drvdata(pdev);
 422         int i;
 423
 424         for (i = 0; i < CHT_WC_LED_COUNT; i++)
 425                 cht_wc_leds_brightness_set(&leds->leds[i].cdev, 0);
 426
 427         /* Restore LED1 regs if hw-control was active else leave LED1 off */
 428         if (!(leds->led1_initial_regs.ctrl & CHT_WC_LED1_SWCTL))
 429                 cht_wc_led_restore_regs(&leds->leds[0], &leds->led1_initial_regs);
 430 }
 431
 432 /* On suspend save current settings and turn LEDs off */
 433 static int cht_wc_leds_suspend(struct device *dev)
 434 {
 435         struct cht_wc_leds *leds = dev_get_drvdata(dev);
 436         int i, ret;
 437
 438         for (i = 0; i < CHT_WC_LED_COUNT; i++) {
 439                 ret = cht_wc_led_save_regs(&leds->leds[i], &leds->leds[i].saved_regs);
 440                 if (ret < 0)
 441                         return ret;
 442         }
 443
 444         cht_wc_leds_disable(to_platform_device(dev));
 445         return 0;
 446 }
 447
 448 /* On resume restore the saved settings */
 449 static int cht_wc_leds_resume(struct device *dev)
 450 {
 451         struct cht_wc_leds *leds = dev_get_drvdata(dev);
 452         int i;
 453
 454         for (i = 0; i < CHT_WC_LED_COUNT; i++)
 455                 cht_wc_led_restore_regs(&leds->leds[i], &leds->leds[i].saved_regs);
 456
 457         return 0;
 458 }
 459
 460 static DEFINE_SIMPLE_DEV_PM_OPS(cht_wc_leds_pm, cht_wc_leds_suspend, cht_wc_leds_resume);
 461
 462 static struct platform_driver cht_wc_leds_driver = {
 463         .probe = cht_wc_leds_probe,
 464         .remove = cht_wc_leds_remove,
 465         .shutdown = cht_wc_leds_disable,
 466         .driver = {
 467                 .name = "cht_wcove_leds",
 468                 .pm = pm_sleep_ptr(&cht_wc_leds_pm),
 469         },
 470 };
 471 module_platform_driver(cht_wc_leds_driver);
 472
 473 MODULE_ALIAS("platform:cht_wcove_leds");
 474 MODULE_DESCRIPTION("Intel Cherry Trail Whiskey Cove PMIC LEDs driver");
 475 MODULE_AUTHOR("Yauhen Kharuzhy <jekhor@gmail.com>");
 476 MODULE_LICENSE("GPL");