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         u8 gdc;
 105         u8 gfrq;
 106 };
 107
 108 struct pca963x {
 109         struct pca963x_chipdef *chipdef;
 110         struct mutex mutex;
 111         struct i2c_client *client;
 112         unsigned long leds_on;
 113         struct pca963x_led leds[];
 114 };
 115
 116 static int pca963x_brightness(struct pca963x_led *led,
 117                               enum led_brightness brightness)
 118 {
 119         struct i2c_client *client = led->chip->client;
 120         struct pca963x_chipdef *chipdef = led->chip->chipdef;
 121         u8 ledout_addr, ledout, mask, val;
 122         int shift;
 123         int ret;
 124
 125         ledout_addr = chipdef->ledout_base + (led->led_num / 4);
 126         shift = 2 * (led->led_num % 4);
 127         mask = 0x3 << shift;
 128         ledout = i2c_smbus_read_byte_data(client, ledout_addr);
 129
 130         switch (brightness) {
 131         case LED_FULL:
 132                 val = (ledout & ~mask) | (PCA963X_LED_ON << shift);
 133                 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
 134                 break;
 135         case LED_OFF:
 136                 val = ledout & ~mask;
 137                 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
 138                 break;
 139         default:
 140                 ret = i2c_smbus_write_byte_data(client,
 141                                                 PCA963X_PWM_BASE +
 142                                                 led->led_num,
 143                                                 brightness);
 144                 if (ret < 0)
 145                         return ret;
 146
 147                 val = (ledout & ~mask) | (PCA963X_LED_PWM << shift);
 148                 ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
 149                 break;
 150         }
 151
 152         return ret;
 153 }
 154
 155 static void pca963x_blink(struct pca963x_led *led)
 156 {
 157         struct i2c_client *client = led->chip->client;
 158         struct pca963x_chipdef *chipdef = led->chip->chipdef;
 159         u8 ledout_addr, ledout, mask, val, mode2;
 160         int shift;
 161
 162         ledout_addr = chipdef->ledout_base + (led->led_num / 4);
 163         shift = 2 * (led->led_num % 4);
 164         mask = 0x3 << shift;
 165         mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
 166
 167         i2c_smbus_write_byte_data(client, chipdef->grppwm, led->gdc);
 168
 169         i2c_smbus_write_byte_data(client, chipdef->grpfreq, led->gfrq);
 170
 171         if (!(mode2 & PCA963X_MODE2_DMBLNK))
 172                 i2c_smbus_write_byte_data(client, PCA963X_MODE2,
 173                                           mode2 | PCA963X_MODE2_DMBLNK);
 174
 175         mutex_lock(&led->chip->mutex);
 176
 177         ledout = i2c_smbus_read_byte_data(client, ledout_addr);
 178         if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift)) {
 179                 val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
 180                 i2c_smbus_write_byte_data(client, ledout_addr, val);
 181         }
 182
 183         mutex_unlock(&led->chip->mutex);
 184 }
 185
 186 static int pca963x_power_state(struct pca963x_led *led)
 187 {
 188         struct i2c_client *client = led->chip->client;
 189         unsigned long *leds_on = &led->chip->leds_on;
 190         unsigned long cached_leds = *leds_on;
 191
 192         if (led->led_cdev.brightness)
 193                 set_bit(led->led_num, leds_on);
 194         else
 195                 clear_bit(led->led_num, leds_on);
 196
 197         if (!(*leds_on) != !cached_leds)
 198                 return i2c_smbus_write_byte_data(client, PCA963X_MODE1,
 199                                                  *leds_on ? 0 : BIT(4));
 200
 201         return 0;
 202 }
 203
 204 static int pca963x_led_set(struct led_classdev *led_cdev,
 205                            enum led_brightness value)
 206 {
 207         struct pca963x_led *led;
 208         int ret;
 209
 210         led = container_of(led_cdev, struct pca963x_led, led_cdev);
 211
 212         mutex_lock(&led->chip->mutex);
 213
 214         ret = pca963x_brightness(led, value);
 215         if (ret < 0)
 216                 goto unlock;
 217         ret = pca963x_power_state(led);
 218
 219 unlock:
 220         mutex_unlock(&led->chip->mutex);
 221         return ret;
 222 }
 223
 224 static unsigned int pca963x_period_scale(struct pca963x_led *led,
 225                                          unsigned int val)
 226 {
 227         unsigned int scaling = led->chip->chipdef->scaling;
 228
 229         return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
 230 }
 231
 232 static int pca963x_blink_set(struct led_classdev *led_cdev,
 233                              unsigned long *delay_on, unsigned long *delay_off)
 234 {
 235         unsigned long time_on, time_off, period;
 236         struct pca963x_led *led;
 237         u8 gdc, gfrq;
 238
 239         led = container_of(led_cdev, struct pca963x_led, led_cdev);
 240
 241         time_on = *delay_on;
 242         time_off = *delay_off;
 243
 244         /* If both zero, pick reasonable defaults of 500ms each */
 245         if (!time_on && !time_off) {
 246                 time_on = 500;
 247                 time_off = 500;
 248         }
 249
 250         period = pca963x_period_scale(led, time_on + time_off);
 251
 252         /* If period not supported by hardware, default to someting sane. */
 253         if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 254             (period > PCA963X_BLINK_PERIOD_MAX)) {
 255                 time_on = 500;
 256                 time_off = 500;
 257                 period = pca963x_period_scale(led, 1000);
 258         }
 259
 260         /*
 261          * From manual: duty cycle = (GDC / 256) ->
 262          *      (time_on / period) = (GDC / 256) ->
 263          *              GDC = ((time_on * 256) / period)
 264          */
 265         gdc = (pca963x_period_scale(led, time_on) * 256) / period;
 266
 267         /*
 268          * From manual: period = ((GFRQ + 1) / 24) in seconds.
 269          * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 270          *              GFRQ = ((period * 24 / 1000) - 1)
 271          */
 272         gfrq = (period * 24 / 1000) - 1;
 273
 274         led->gdc = gdc;
 275         led->gfrq = gfrq;
 276
 277         pca963x_blink(led);
 278
 279         *delay_on = time_on;
 280         *delay_off = time_off;
 281
 282         return 0;
 283 }
 284
 285 static int pca963x_register_leds(struct i2c_client *client,
 286                                  struct pca963x *chip)
 287 {
 288         struct pca963x_chipdef *chipdef = chip->chipdef;
 289         struct pca963x_led *led = chip->leds;
 290         struct device *dev = &client->dev;
 291         struct fwnode_handle *child;
 292         bool hw_blink;
 293         s32 mode2;
 294         u32 reg;
 295         int ret;
 296
 297         if (device_property_read_u32(dev, "nxp,period-scale",
 298                                      &chipdef->scaling))
 299                 chipdef->scaling = 1000;
 300
 301         hw_blink = device_property_read_bool(dev, "nxp,hw-blink");
 302
 303         mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
 304         if (mode2 < 0)
 305                 return mode2;
 306
 307         /* default to open-drain unless totem pole (push-pull) is specified */
 308         if (device_property_read_bool(dev, "nxp,totem-pole"))
 309                 mode2 |= PCA963X_MODE2_OUTDRV;
 310         else
 311                 mode2 &= ~PCA963X_MODE2_OUTDRV;
 312
 313         /* default to non-inverted output, unless inverted is specified */
 314         if (device_property_read_bool(dev, "nxp,inverted-out"))
 315                 mode2 |= PCA963X_MODE2_INVRT;
 316         else
 317                 mode2 &= ~PCA963X_MODE2_INVRT;
 318
 319         ret = i2c_smbus_write_byte_data(client, PCA963X_MODE2, mode2);
 320         if (ret < 0)
 321                 return ret;
 322
 323         device_for_each_child_node(dev, child) {
 324                 struct led_init_data init_data = {};
 325                 char default_label[32];
 326
 327                 ret = fwnode_property_read_u32(child, "reg", &reg);
 328                 if (ret || reg >= chipdef->n_leds) {
 329                         dev_err(dev, "Invalid 'reg' property for node %pfw\n",
 330                                 child);
 331                         ret = -EINVAL;
 332                         goto err;
 333                 }
 334
 335                 led->led_num = reg;
 336                 led->chip = chip;
 337                 led->led_cdev.brightness_set_blocking = pca963x_led_set;
 338                 if (hw_blink)
 339                         led->led_cdev.blink_set = pca963x_blink_set;
 340
 341                 init_data.fwnode = child;
 342                 /* for backwards compatibility */
 343                 init_data.devicename = "pca963x";
 344                 snprintf(default_label, sizeof(default_label), "%d:%.2x:%u",
 345                          client->adapter->nr, client->addr, reg);
 346                 init_data.default_label = default_label;
 347
 348                 ret = devm_led_classdev_register_ext(dev, &led->led_cdev,
 349                                                      &init_data);
 350                 if (ret) {
 351                         dev_err(dev, "Failed to register LED for node %pfw\n",
 352                                 child);
 353                         goto err;
 354                 }
 355
 356                 ++led;
 357         }
 358
 359         return 0;
 360 err:
 361         fwnode_handle_put(child);
 362         return ret;
 363 }
 364
 365 static const struct of_device_id of_pca963x_match[] = {
 366         { .compatible = "nxp,pca9632", },
 367         { .compatible = "nxp,pca9633", },
 368         { .compatible = "nxp,pca9634", },
 369         { .compatible = "nxp,pca9635", },
 370         {},
 371 };
 372 MODULE_DEVICE_TABLE(of, of_pca963x_match);
 373
 374 static int pca963x_probe(struct i2c_client *client,
 375                          const struct i2c_device_id *id)
 376 {
 377         struct device *dev = &client->dev;
 378         struct pca963x_chipdef *chipdef;
 379         struct pca963x *chip;
 380         int i, count;
 381
 382         chipdef = &pca963x_chipdefs[id->driver_data];
 383
 384         count = device_get_child_node_count(dev);
 385         if (!count || count > chipdef->n_leds) {
 386                 dev_err(dev, "Node %pfw must define between 1 and %d LEDs\n",
 387                         dev_fwnode(dev), chipdef->n_leds);
 388                 return -EINVAL;
 389         }
 390
 391         chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
 392         if (!chip)
 393                 return -ENOMEM;
 394
 395         i2c_set_clientdata(client, chip);
 396
 397         mutex_init(&chip->mutex);
 398         chip->chipdef = chipdef;
 399         chip->client = client;
 400
 401         /* Turn off LEDs by default*/
 402         for (i = 0; i < chipdef->n_leds / 4; i++)
 403                 i2c_smbus_write_byte_data(client, chipdef->ledout_base + i, 0x00);
 404
 405         /* Disable LED all-call address, and power down initially */
 406         i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));
 407
 408         return pca963x_register_leds(client, chip);
 409 }
 410
 411 static struct i2c_driver pca963x_driver = {
 412         .driver = {
 413                 .name   = "leds-pca963x",
 414                 .of_match_table = of_pca963x_match,
 415         },
 416         .probe  = pca963x_probe,
 417         .id_table = pca963x_id,
 418 };
 419
 420 module_i2c_driver(pca963x_driver);
 421
 422 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 423 MODULE_DESCRIPTION("PCA963X LED driver");
 424 MODULE_LICENSE("GPL v2");