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_MODE2_OUTDRV    0x04    /* Open-drain or totem pole */
  43 #define PCA963X_MODE2_INVRT     0x10    /* Normal or inverted direction */
  44 #define PCA963X_MODE2_DMBLNK    0x20    /* Enable blinking */
  45
  46 #define PCA963X_MODE1           0x00
  47 #define PCA963X_MODE2           0x01
  48 #define PCA963X_PWM_BASE        0x02
  49
  50 enum pca963x_type {
  51         pca9633,
  52         pca9634,
  53         pca9635,
  54 };
  55
  56 struct pca963x_chipdef {
  57         u8                      grppwm;
  58         u8                      grpfreq;
  59         u8                      ledout_base;
  60         int                     n_leds;
  61         unsigned int            scaling;
  62 };
  63
  64 static struct pca963x_chipdef pca963x_chipdefs[] = {
  65         [pca9633] = {
  66                 .grppwm         = 0x6,
  67                 .grpfreq        = 0x7,
  68                 .ledout_base    = 0x8,
  69                 .n_leds         = 4,
  70         },
  71         [pca9634] = {
  72                 .grppwm         = 0xa,
  73                 .grpfreq        = 0xb,
  74                 .ledout_base    = 0xc,
  75                 .n_leds         = 8,
  76         },
  77         [pca9635] = {
  78                 .grppwm         = 0x12,
  79                 .grpfreq        = 0x13,
  80                 .ledout_base    = 0x14,
  81                 .n_leds         = 16,
  82         },
  83 };
  84
  85 /* Total blink period in milliseconds */
  86 #define PCA963X_BLINK_PERIOD_MIN        42
  87 #define PCA963X_BLINK_PERIOD_MAX        10667
  88
  89 static const struct i2c_device_id pca963x_id[] = {
  90         { "pca9632", pca9633 },
  91         { "pca9633", pca9633 },
  92         { "pca9634", pca9634 },
  93         { "pca9635", pca9635 },
  94         { }
  95 };
  96 MODULE_DEVICE_TABLE(i2c, pca963x_id);
  97
  98 struct pca963x;
  99
 100 struct pca963x_led {
 101         struct pca963x *chip;
 102         struct led_classdev led_cdev;
 103         int led_num; /* 0 .. 15 potentially */
 104         bool blinking;
 105         u8 gdc;
 106         u8 gfrq;
 107 };
 108
 109 struct pca963x {
 110         struct pca963x_chipdef *chipdef;
 111         struct mutex mutex;
 112         struct i2c_client *client;
 113         unsigned long leds_on;
 114         struct pca963x_led leds[];
 115 };
 116
 117 static int pca963x_brightness(struct pca963x_led *led,
 118                               enum led_brightness brightness)
 119 {
 120         struct i2c_client *client = led->chip->client;
 121         struct pca963x_chipdef *chipdef = led->chip->chipdef;
 122         u8 ledout_addr, ledout, mask, val;
 123         int shift;
 124         int ret;
 125
 126         ledout_addr = chipdef->ledout_base + (led->led_num / 4);
 127         shift = 2 * (led->led_num % 4);
 128         mask = 0x3 << shift;
 129         ledout = i2c_smbus_read_byte_data(client, ledout_addr);
 130
 131         switch (brightness) {
 132         case LED_FULL:
 133                 if (led->blinking) {
 134                         val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
 135                         ret = i2c_smbus_write_byte_data(client,
 136                                                 PCA963X_PWM_BASE +
 137                                                 led->led_num,
 138                                                 LED_FULL);
 139                 } else {
 140                         val = (ledout & ~mask) | (PCA963X_LED_ON << shift);
 141                 }
 142                 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
 143                 break;
 144         case LED_OFF:
 145                 val = ledout & ~mask;
 146                 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
 147                 led->blinking = false;
 148                 break;
 149         default:
 150                 ret = i2c_smbus_write_byte_data(client,
 151                                                 PCA963X_PWM_BASE +
 152                                                 led->led_num,
 153                                                 brightness);
 154                 if (ret < 0)
 155                         return ret;
 156
 157                 if (led->blinking)
 158                         val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
 159                 else
 160                         val = (ledout & ~mask) | (PCA963X_LED_PWM << shift);
 161
 162                 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
 163                 break;
 164         }
 165
 166         return ret;
 167 }
 168
 169 static void pca963x_blink(struct pca963x_led *led)
 170 {
 171         struct i2c_client *client = led->chip->client;
 172         struct pca963x_chipdef *chipdef = led->chip->chipdef;
 173         u8 ledout_addr, ledout, mask, val, mode2;
 174         int shift;
 175
 176         ledout_addr = chipdef->ledout_base + (led->led_num / 4);
 177         shift = 2 * (led->led_num % 4);
 178         mask = 0x3 << shift;
 179         mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
 180
 181         i2c_smbus_write_byte_data(client, chipdef->grppwm, led->gdc);
 182
 183         i2c_smbus_write_byte_data(client, chipdef->grpfreq, led->gfrq);
 184
 185         if (!(mode2 & PCA963X_MODE2_DMBLNK))
 186                 i2c_smbus_write_byte_data(client, PCA963X_MODE2,
 187                                           mode2 | PCA963X_MODE2_DMBLNK);
 188
 189         mutex_lock(&led->chip->mutex);
 190
 191         ledout = i2c_smbus_read_byte_data(client, ledout_addr);
 192         if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift)) {
 193                 val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
 194                 i2c_smbus_write_byte_data(client, ledout_addr, val);
 195         }
 196
 197         mutex_unlock(&led->chip->mutex);
 198         led->blinking = true;
 199 }
 200
 201 static int pca963x_power_state(struct pca963x_led *led)
 202 {
 203         struct i2c_client *client = led->chip->client;
 204         unsigned long *leds_on = &led->chip->leds_on;
 205         unsigned long cached_leds = *leds_on;
 206
 207         if (led->led_cdev.brightness)
 208                 set_bit(led->led_num, leds_on);
 209         else
 210                 clear_bit(led->led_num, leds_on);
 211
 212         if (!(*leds_on) != !cached_leds)
 213                 return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
 214                                                  *leds_on ? 0 : BIT(4));
 215
 216         return 0;
 217 }
 218
 219 static int pca963x_led_set(struct led_classdev *led_cdev,
 220                            enum led_brightness value)
 221 {
 222         struct pca963x_led *led;
 223         int ret;
 224
 225         led = container_of(led_cdev, struct pca963x_led, led_cdev);
 226
 227         mutex_lock(&led->chip->mutex);
 228
 229         ret = pca963x_brightness(led, value);
 230         if (ret < 0)
 231                 goto unlock;
 232         ret = pca963x_power_state(led);
 233
 234 unlock:
 235         mutex_unlock(&led->chip->mutex);
 236         return ret;
 237 }
 238
 239 static unsigned int pca963x_period_scale(struct pca963x_led *led,
 240                                          unsigned int val)
 241 {
 242         unsigned int scaling = led->chip->chipdef->scaling;
 243
 244         return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
 245 }
 246
 247 static int pca963x_blink_set(struct led_classdev *led_cdev,
 248                              unsigned long *delay_on, unsigned long *delay_off)
 249 {
 250         unsigned long time_on, time_off, period;
 251         struct pca963x_led *led;
 252         u8 gdc, gfrq;
 253
 254         led = container_of(led_cdev, struct pca963x_led, led_cdev);
 255
 256         time_on = *delay_on;
 257         time_off = *delay_off;
 258
 259         /* If both zero, pick reasonable defaults of 500ms each */
 260         if (!time_on && !time_off) {
 261                 time_on = 500;
 262                 time_off = 500;
 263         }
 264
 265         period = pca963x_period_scale(led, time_on + time_off);
 266
 267         /* If period not supported by hardware, default to someting sane. */
 268         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 269             (period > PCA963X_BLINK_PERIOD_MAX)) {
 270                 time_on = 500;
 271                 time_off = 500;
 272                 period = pca963x_period_scale(led, 1000);
 273         }
 274
 275         /*
 276          * From manual: duty cycle = (GDC / 256) ->
 277          *      (time_on / period) = (GDC / 256) ->
 278          *              GDC = ((time_on * 256) / period)
 279          */
 280         gdc = (pca963x_period_scale(led, time_on) * 256) / period;
 281
 282         /*
 283          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 284          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 285          *              GFRQ = ((period * 24 / 1000) - 1)
 286          */
 287         gfrq = (period * 24 / 1000) - 1;
 288
 289         led->gdc = gdc;
 290         led->gfrq = gfrq;
 291
 292         pca963x_blink(led);
 293         led->led_cdev.brightness = LED_FULL;
 294         pca963x_led_set(led_cdev, LED_FULL);
 295
 296         *delay_on = time_on;
 297         *delay_off = time_off;
 298
 299         return 0;
 300 }
 301
 302 static int pca963x_register_leds(struct i2c_client *client,
 303                                  struct pca963x *chip)
 304 {
 305         struct pca963x_chipdef *chipdef = chip->chipdef;
 306         struct pca963x_led *led = chip->leds;
 307         struct device *dev = &client->dev;
 308         struct fwnode_handle *child;
 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(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                         ret = -EINVAL;
 349                         goto err;
 350                 }
 351
 352                 led->led_num = reg;
 353                 led->chip = chip;
 354                 led->led_cdev.brightness_set_blocking = pca963x_led_set;
 355                 if (hw_blink)
 356                         led->led_cdev.blink_set = pca963x_blink_set;
 357                 led->blinking = false;
 358
 359                 init_data.fwnode = child;
 360                 /* for backwards compatibility */
 361                 init_data.devicename = "pca963x";
 362                 snprintf(default_label, sizeof(default_label), "%d:%.2x:%u",
 363                          client->adapter->nr, client->addr, reg);
 364                 init_data.default_label = default_label;
 365
 366                 ret = devm_led_classdev_register_ext(dev, &led->led_cdev,
 367                                                      &init_data);
 368                 if (ret) {
 369                         dev_err(dev, "Failed to register LED for node %pfw\n",
 370                                 child);
 371                         goto err;
 372                 }
 373
 374                 ++led;
 375         }
 376
 377         return 0;
 378 err:
 379         fwnode_handle_put(child);
 380         return ret;
 381 }
 382
 383 static const struct of_device_id of_pca963x_match[] = {
 384         { .compatible = "nxp,pca9632", },
 385         { .compatible = "nxp,pca9633", },
 386         { .compatible = "nxp,pca9634", },
 387         { .compatible = "nxp,pca9635", },
 388         {},
 389 };
 390 MODULE_DEVICE_TABLE(of, of_pca963x_match);
 391
 392 static int pca963x_probe(struct i2c_client *client)
 393 {
 394         const struct i2c_device_id *id = i2c_client_get_device_id(client);
 395         struct device *dev = &client->dev;
 396         struct pca963x_chipdef *chipdef;
 397         struct pca963x *chip;
 398         int i, count;
 399
 400         chipdef = &pca963x_chipdefs[id->driver_data];
 401
 402         count = device_get_child_node_count(dev);
 403         if (!count || count > chipdef->n_leds) {
 404                 dev_err(dev, "Node %pfw must define between 1 and %d LEDs\n",
 405                         dev_fwnode(dev), chipdef->n_leds);
 406                 return -EINVAL;
 407         }
 408
 409         chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
 410         if (!chip)
 411                 return -ENOMEM;
 412
 413         i2c_set_clientdata(client, chip);
 414
 415         mutex_init(&chip->mutex);
 416         chip->chipdef = chipdef;
 417         chip->client = client;
 418
 419         /* Turn off LEDs by default*/
 420         for (i = 0; i < chipdef->n_leds / 4; i++)
 421                 i2c_smbus_write_byte_data(client, chipdef->ledout_base + i, 0x00);
 422
 423         /* Disable LED all-call address, and power down initially */
 424         i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
 425
 426         return pca963x_register_leds(client, chip);
 427 }
 428
 429 static struct i2c_driver pca963x_driver = {
 430         .driver = {
 431                 .name   = "leds-pca963x",
 432                 .of_match_table = of_pca963x_match,
 433         },
 434         .probe = pca963x_probe,
 435         .id_table = pca963x_id,
 436 };
 437
 438 module_i2c_driver(pca963x_driver);
 439
 440 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 441 MODULE_DESCRIPTION("PCA963X LED driver");
 442 MODULE_LICENSE("GPL v2");