drivers/leds/leds-pca963x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2011 bct electronic GmbH
   4  * Copyright 2013 Qtechnology/AS
   5  *
   6  * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
   7  * Author: Ricardo Ribalda <ribalda@kernel.org>
   8  *
   9  * Based on leds-pca955x.c
  10  *
  11  * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
  12  * LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.)
  13  *
  14  * Note that hardware blinking violates the leds infrastructure driver
  15  * interface since the hardware only supports blinking all LEDs with the
  16  * same delay_on/delay_off rates.  That is, only the LEDs that are set to
  17  * blink will actually blink but all LEDs that are set to blink will blink
  18  * in identical fashion.  The delay_on/delay_off values of the last LED
  19  * that is set to blink will be used for all of the blinking LEDs.
  20  * Hardware blinking is disabled by default but can be enabled by setting
  21  * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
  22  * or by adding the 'nxp,hw-blink' property to the DTS.
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/delay.h>
  27 #include <linux/string.h>
  28 #include <linux/ctype.h>
  29 #include <linux/leds.h>
  30 #include <linux/err.h>
  31 #include <linux/i2c.h>
  32 #include <linux/property.h>
  33 #include <linux/slab.h>
  34 #include <linux/of.h>
  35
  36 /* LED select registers determine the source that drives LED outputs */
  37 #define PCA963X_LED_OFF         0x0     /* LED driver off */
  38 #define PCA963X_LED_ON          0x1     /* LED driver on */
  39 #define PCA963X_LED_PWM         0x2     /* Controlled through PWM */
  40 #define PCA963X_LED_GRP_PWM     0x3     /* Controlled through PWM/GRPPWM */
  41
  42 #define PCA963X_MODE1_SLEEP     0x04    /* Normal mode or Low Power mode, oscillator off */
  43 #define PCA963X_MODE2_OUTDRV    0x04    /* Open-drain or totem pole */
  44 #define PCA963X_MODE2_INVRT     0x10    /* Normal or inverted direction */
  45 #define PCA963X_MODE2_DMBLNK    0x20    /* Enable blinking */
  46
  47 #define PCA963X_MODE1           0x00
  48 #define PCA963X_MODE2           0x01
  49 #define PCA963X_PWM_BASE        0x02
  50
  51 enum pca963x_type {
  52         pca9633,
  53         pca9634,
  54         pca9635,
  55 };
  56
  57 struct pca963x_chipdef {
  58         u8                      grppwm;
  59         u8                      grpfreq;
  60         u8                      ledout_base;
  61         int                     n_leds;
  62         unsigned int            scaling;
  63 };
  64
  65 static struct pca963x_chipdef pca963x_chipdefs[] = {
  66         [pca9633] = {
  67                 .grppwm         = 0x6,
  68                 .grpfreq        = 0x7,
  69                 .ledout_base    = 0x8,
  70                 .n_leds         = 4,
  71         },
  72         [pca9634] = {
  73                 .grppwm         = 0xa,
  74                 .grpfreq        = 0xb,
  75                 .ledout_base    = 0xc,
  76                 .n_leds         = 8,
  77         },
  78         [pca9635] = {
  79                 .grppwm         = 0x12,
  80                 .grpfreq        = 0x13,
  81                 .ledout_base    = 0x14,
  82                 .n_leds         = 16,
  83         },
  84 };
  85
  86 /* Total blink period in milliseconds */
  87 #define PCA963X_BLINK_PERIOD_MIN        42
  88 #define PCA963X_BLINK_PERIOD_MAX        10667
  89
  90 static const struct i2c_device_id pca963x_id[] = {
  91         { "pca9632", pca9633 },
  92         { "pca9633", pca9633 },
  93         { "pca9634", pca9634 },
  94         { "pca9635", pca9635 },
  95         { }
  96 };
  97 MODULE_DEVICE_TABLE(i2c, pca963x_id);
  98
  99 struct pca963x;
 100
 101 struct pca963x_led {
 102         struct pca963x *chip;
 103         struct led_classdev led_cdev;
 104         int led_num; /* 0 .. 15 potentially */
 105         bool blinking;
 106         u8 gdc;
 107         u8 gfrq;
 108 };
 109
 110 struct pca963x {
 111         struct pca963x_chipdef *chipdef;
 112         struct mutex mutex;
 113         struct i2c_client *client;
 114         unsigned long leds_on;
 115         struct pca963x_led leds[];
 116 };
 117
 118 static int pca963x_brightness(struct pca963x_led *led,
 119                               enum led_brightness brightness)
 120 {
 121         struct i2c_client *client = led->chip->client;
 122         struct pca963x_chipdef *chipdef = led->chip->chipdef;
 123         u8 ledout_addr, ledout, mask, val;
 124         int shift;
 125         int ret;
 126
 127         ledout_addr = chipdef->ledout_base + (led->led_num / 4);
 128         shift = 2 * (led->led_num % 4);
 129         mask = 0x3 << shift;
 130         ledout = i2c_smbus_read_byte_data(client, ledout_addr);
 131
 132         switch (brightness) {
 133         case LED_FULL:
 134                 if (led->blinking) {
 135                         val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
 136                         ret = i2c_smbus_write_byte_data(client,
 137                                                 PCA963X_PWM_BASE +
 138                                                 led->led_num,
 139                                                 LED_FULL);
 140                 } else {
 141                         val = (ledout & ~mask) | (PCA963X_LED_ON << shift);
 142                 }
 143                 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
 144                 break;
 145         case LED_OFF:
 146                 val = ledout & ~mask;
 147                 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
 148                 led->blinking = false;
 149                 break;
 150         default:
 151                 ret = i2c_smbus_write_byte_data(client,
 152                                                 PCA963X_PWM_BASE +
 153                                                 led->led_num,
 154                                                 brightness);
 155                 if (ret < 0)
 156                         return ret;
 157
 158                 if (led->blinking)
 159                         val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
 160                 else
 161                         val = (ledout & ~mask) | (PCA963X_LED_PWM << shift);
 162
 163                 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
 164                 break;
 165         }
 166
 167         return ret;
 168 }
 169
 170 static void pca963x_blink(struct pca963x_led *led)
 171 {
 172         struct i2c_client *client = led->chip->client;
 173         struct pca963x_chipdef *chipdef = led->chip->chipdef;
 174         u8 ledout_addr, ledout, mask, val, mode2;
 175         int shift;
 176
 177         ledout_addr = chipdef->ledout_base + (led->led_num / 4);
 178         shift = 2 * (led->led_num % 4);
 179         mask = 0x3 << shift;
 180         mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
 181
 182         i2c_smbus_write_byte_data(client, chipdef->grppwm, led->gdc);
 183
 184         i2c_smbus_write_byte_data(client, chipdef->grpfreq, led->gfrq);
 185
 186         if (!(mode2 & PCA963X_MODE2_DMBLNK))
 187                 i2c_smbus_write_byte_data(client, PCA963X_MODE2,
 188                                           mode2 | PCA963X_MODE2_DMBLNK);
 189
 190         mutex_lock(&led->chip->mutex);
 191
 192         ledout = i2c_smbus_read_byte_data(client, ledout_addr);
 193         if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift)) {
 194                 val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
 195                 i2c_smbus_write_byte_data(client, ledout_addr, val);
 196         }
 197
 198         mutex_unlock(&led->chip->mutex);
 199         led->blinking = true;
 200 }
 201
 202 static int pca963x_power_state(struct pca963x_led *led)
 203 {
 204         struct i2c_client *client = led->chip->client;
 205         unsigned long *leds_on = &led->chip->leds_on;
 206         unsigned long cached_leds = *leds_on;
 207
 208         if (led->led_cdev.brightness)
 209                 set_bit(led->led_num, leds_on);
 210         else
 211                 clear_bit(led->led_num, leds_on);
 212
 213         if (!(*leds_on) != !cached_leds)
 214                 return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
 215                                                  *leds_on ? 0 : BIT(4));
 216
 217         return 0;
 218 }
 219
 220 static int pca963x_led_set(struct led_classdev *led_cdev,
 221                            enum led_brightness value)
 222 {
 223         struct pca963x_led *led;
 224         int ret;
 225
 226         led = container_of(led_cdev, struct pca963x_led, led_cdev);
 227
 228         mutex_lock(&led->chip->mutex);
 229
 230         ret = pca963x_brightness(led, value);
 231         if (ret < 0)
 232                 goto unlock;
 233         ret = pca963x_power_state(led);
 234
 235 unlock:
 236         mutex_unlock(&led->chip->mutex);
 237         return ret;
 238 }
 239
 240 static unsigned int pca963x_period_scale(struct pca963x_led *led,
 241                                          unsigned int val)
 242 {
 243         unsigned int scaling = led->chip->chipdef->scaling;
 244
 245         return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
 246 }
 247
 248 static int pca963x_blink_set(struct led_classdev *led_cdev,
 249                              unsigned long *delay_on, unsigned long *delay_off)
 250 {
 251         unsigned long time_on, time_off, period;
 252         struct pca963x_led *led;
 253         u8 gdc, gfrq;
 254
 255         led = container_of(led_cdev, struct pca963x_led, led_cdev);
 256
 257         time_on = *delay_on;
 258         time_off = *delay_off;
 259
 260         /* If both zero, pick reasonable defaults of 500ms each */
 261         if (!time_on && !time_off) {
 262                 time_on = 500;
 263                 time_off = 500;
 264         }
 265
 266         period = pca963x_period_scale(led, time_on + time_off);
 267
 268         /* If period not supported by hardware, default to someting sane. */
 269         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 270             (period > PCA963X_BLINK_PERIOD_MAX)) {
 271                 time_on = 500;
 272                 time_off = 500;
 273                 period = pca963x_period_scale(led, 1000);
 274         }
 275
 276         /*
 277          * From manual: duty cycle = (GDC / 256) ->
 278          *      (time_on / period) = (GDC / 256) ->
 279          *              GDC = ((time_on * 256) / period)
 280          */
 281         gdc = (pca963x_period_scale(led, time_on) * 256) / period;
 282
 283         /*
 284          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 285          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 286          *              GFRQ = ((period * 24 / 1000) - 1)
 287          */
 288         gfrq = (period * 24 / 1000) - 1;
 289
 290         led->gdc = gdc;
 291         led->gfrq = gfrq;
 292
 293         pca963x_blink(led);
 294         led->led_cdev.brightness = LED_FULL;
 295         pca963x_led_set(led_cdev, LED_FULL);
 296
 297         *delay_on = time_on;
 298         *delay_off = time_off;
 299
 300         return 0;
 301 }
 302
 303 static int pca963x_register_leds(struct i2c_client *client,
 304                                  struct pca963x *chip)
 305 {
 306         struct pca963x_chipdef *chipdef = chip->chipdef;
 307         struct pca963x_led *led = chip->leds;
 308         struct device *dev = &client->dev;
 309         bool hw_blink;
 310         s32 mode2;
 311         u32 reg;
 312         int ret;
 313
 314         if (device_property_read_u32(dev, "nxp,period-scale",
 315                                      &chipdef->scaling))
 316                 chipdef->scaling = 1000;
 317
 318         hw_blink = device_property_read_bool(dev, "nxp,hw-blink");
 319
 320         mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
 321         if (mode2 < 0)
 322                 return mode2;
 323
 324         /* default to open-drain unless totem pole (push-pull) is specified */
 325         if (device_property_read_bool(dev, "nxp,totem-pole"))
 326                 mode2 |= PCA963X_MODE2_OUTDRV;
 327         else
 328                 mode2 &= ~PCA963X_MODE2_OUTDRV;
 329
 330         /* default to non-inverted output, unless inverted is specified */
 331         if (device_property_read_bool(dev, "nxp,inverted-out"))
 332                 mode2 |= PCA963X_MODE2_INVRT;
 333         else
 334                 mode2 &= ~PCA963X_MODE2_INVRT;
 335
 336         ret = i2c_smbus_write_byte_data(client, PCA963X_MODE2, mode2);
 337         if (ret < 0)
 338                 return ret;
 339
 340         device_for_each_child_node_scoped(dev, child) {
 341                 struct led_init_data init_data = {};
 342                 char default_label[32];
 343
 344                 ret = fwnode_property_read_u32(child, "reg", &reg);
 345                 if (ret || reg >= chipdef->n_leds) {
 346                         dev_err(dev, "Invalid 'reg' property for node %pfw\n",
 347                                 child);
 348                         return -EINVAL;
 349                 }
 350
 351                 led->led_num = reg;
 352                 led->chip = chip;
 353                 led->led_cdev.brightness_set_blocking = pca963x_led_set;
 354                 if (hw_blink)
 355                         led->led_cdev.blink_set = pca963x_blink_set;
 356                 led->blinking = false;
 357
 358                 init_data.fwnode = child;
 359                 /* for backwards compatibility */
 360                 init_data.devicename = "pca963x";
 361                 snprintf(default_label, sizeof(default_label), "%d:%.2x:%u",
 362                          client->adapter->nr, client->addr, reg);
 363                 init_data.default_label = default_label;
 364
 365                 ret = devm_led_classdev_register_ext(dev, &led->led_cdev,
 366                                                      &init_data);
 367                 if (ret) {
 368                         dev_err(dev, "Failed to register LED for node %pfw\n",
 369                                 child);
 370                         return ret;
 371                 }
 372
 373                 ++led;
 374         }
 375
 376         return 0;
 377 }
 378
 379 static int pca963x_suspend(struct device *dev)
 380 {
 381         struct pca963x *chip = dev_get_drvdata(dev);
 382         u8 reg;
 383
 384         reg = i2c_smbus_read_byte_data(chip->client, PCA963X_MODE1);
 385         reg = reg | BIT(PCA963X_MODE1_SLEEP);
 386         i2c_smbus_write_byte_data(chip->client, PCA963X_MODE1, reg);
 387
 388         return 0;
 389 }
 390
 391 static int pca963x_resume(struct device *dev)
 392 {
 393         struct pca963x *chip = dev_get_drvdata(dev);
 394         u8 reg;
 395
 396         reg = i2c_smbus_read_byte_data(chip->client, PCA963X_MODE1);
 397         reg = reg & ~BIT(PCA963X_MODE1_SLEEP);
 398         i2c_smbus_write_byte_data(chip->client, PCA963X_MODE1, reg);
 399
 400         return 0;
 401 }
 402
 403 static DEFINE_SIMPLE_DEV_PM_OPS(pca963x_pm, pca963x_suspend, pca963x_resume);
 404
 405 static const struct of_device_id of_pca963x_match[] = {
 406         { .compatible = "nxp,pca9632", },
 407         { .compatible = "nxp,pca9633", },
 408         { .compatible = "nxp,pca9634", },
 409         { .compatible = "nxp,pca9635", },
 410         {},
 411 };
 412 MODULE_DEVICE_TABLE(of, of_pca963x_match);
 413
 414 static int pca963x_probe(struct i2c_client *client)
 415 {
 416         const struct i2c_device_id *id = i2c_client_get_device_id(client);
 417         struct device *dev = &client->dev;
 418         struct pca963x_chipdef *chipdef;
 419         struct pca963x *chip;
 420         int i, count;
 421
 422         chipdef = &pca963x_chipdefs[id->driver_data];
 423
 424         count = device_get_child_node_count(dev);
 425         if (!count || count > chipdef->n_leds) {
 426                 dev_err(dev, "Node %pfw must define between 1 and %d LEDs\n",
 427                         dev_fwnode(dev), chipdef->n_leds);
 428                 return -EINVAL;
 429         }
 430
 431         chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
 432         if (!chip)
 433                 return -ENOMEM;
 434
 435         i2c_set_clientdata(client, chip);
 436
 437         mutex_init(&chip->mutex);
 438         chip->chipdef = chipdef;
 439         chip->client = client;
 440
 441         /* Turn off LEDs by default*/
 442         for (i = 0; i < chipdef->n_leds / 4; i++)
 443                 i2c_smbus_write_byte_data(client, chipdef->ledout_base + i, 0x00);
 444
 445         /* Disable LED all-call address, and power down initially */
 446         i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
 447
 448         return pca963x_register_leds(client, chip);
 449 }
 450
 451 static struct i2c_driver pca963x_driver = {
 452         .driver = {
 453                 .name   = "leds-pca963x",
 454                 .of_match_table = of_pca963x_match,
 455                 .pm = pm_sleep_ptr(&pca963x_pm)
 456         },
 457         .probe = pca963x_probe,
 458         .id_table = pca963x_id,
 459 };
 460
 461 module_i2c_driver(pca963x_driver);
 462
 463 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 464 MODULE_DESCRIPTION("PCA963X LED driver");
 465 MODULE_LICENSE("GPL v2");