kernel/drivers/leds/leds-pca9532.c

   1 /*
   2  * pca9532.c - 16-bit Led dimmer
   3  *
   4  * Copyright (C) 2011 Jan Weitzel
   5  * Copyright (C) 2008 Riku Voipio
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; version 2 of the License.
  10  *
  11  * Datasheet: http://www.nxp.com/documents/data_sheet/PCA9532.pdf
  12  *
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/i2c.h>
  17 #include <linux/slab.h>
  18 #include <linux/leds.h>
  19 #include <linux/input.h>
  20 #include <linux/mutex.h>
  21 #include <linux/workqueue.h>
  22 #include <linux/leds-pca9532.h>
  23 #include <linux/gpio.h>
  24
  25 /* m =  num_leds*/
  26 #define PCA9532_REG_INPUT(i)    ((i) >> 3)
  27 #define PCA9532_REG_OFFSET(m)   ((m) >> 4)
  28 #define PCA9532_REG_PSC(m, i)   (PCA9532_REG_OFFSET(m) + 0x1 + (i) * 2)
  29 #define PCA9532_REG_PWM(m, i)   (PCA9532_REG_OFFSET(m) + 0x2 + (i) * 2)
  30 #define LED_REG(m, led)         (PCA9532_REG_OFFSET(m) + 0x5 + (led >> 2))
  31 #define LED_NUM(led)            (led & 0x3)
  32
  33 #define ldev_to_led(c)       container_of(c, struct pca9532_led, ldev)
  34
  35 struct pca9532_chip_info {
  36         u8      num_leds;
  37 };
  38
  39 struct pca9532_data {
  40         struct i2c_client *client;
  41         struct pca9532_led leds[16];
  42         struct mutex update_lock;
  43         struct input_dev *idev;
  44         struct work_struct work;
  45 #ifdef CONFIG_LEDS_PCA9532_GPIO
  46         struct gpio_chip gpio;
  47 #endif
  48         const struct pca9532_chip_info *chip_info;
  49         u8 pwm[2];
  50         u8 psc[2];
  51 };
  52
  53 static int pca9532_probe(struct i2c_client *client,
  54         const struct i2c_device_id *id);
  55 static int pca9532_remove(struct i2c_client *client);
  56
  57 enum {
  58         pca9530,
  59         pca9531,
  60         pca9532,
  61         pca9533,
  62 };
  63
  64 static const struct i2c_device_id pca9532_id[] = {
  65         { "pca9530", pca9530 },
  66         { "pca9531", pca9531 },
  67         { "pca9532", pca9532 },
  68         { "pca9533", pca9533 },
  69         { }
  70 };
  71
  72 MODULE_DEVICE_TABLE(i2c, pca9532_id);
  73
  74 static const struct pca9532_chip_info pca9532_chip_info_tbl[] = {
  75         [pca9530] = {
  76                 .num_leds = 2,
  77         },
  78         [pca9531] = {
  79                 .num_leds = 8,
  80         },
  81         [pca9532] = {
  82                 .num_leds = 16,
  83         },
  84         [pca9533] = {
  85                 .num_leds = 4,
  86         },
  87 };
  88
  89 static struct i2c_driver pca9532_driver = {
  90         .driver = {
  91                 .name = "leds-pca953x",
  92         },
  93         .probe = pca9532_probe,
  94         .remove = pca9532_remove,
  95         .id_table = pca9532_id,
  96 };
  97
  98 /* We have two pwm/blinkers, but 16 possible leds to drive. Additionally,
  99  * the clever Thecus people are using one pwm to drive the beeper. So,
 100  * as a compromise we average one pwm to the values requested by all
 101  * leds that are not ON/OFF.
 102  * */
 103 static int pca9532_calcpwm(struct i2c_client *client, int pwm, int blink,
 104         enum led_brightness value)
 105 {
 106         int a = 0, b = 0, i = 0;
 107         struct pca9532_data *data = i2c_get_clientdata(client);
 108         for (i = 0; i < data->chip_info->num_leds; i++) {
 109                 if (data->leds[i].type == PCA9532_TYPE_LED &&
 110                         data->leds[i].state == PCA9532_PWM0+pwm) {
 111                                 a++;
 112                                 b += data->leds[i].ldev.brightness;
 113                 }
 114         }
 115         if (a == 0) {
 116                 dev_err(&client->dev,
 117                 "fear of division by zero %d/%d, wanted %d\n",
 118                         b, a, value);
 119                 return -EINVAL;
 120         }
 121         b = b/a;
 122         if (b > 0xFF)
 123                 return -EINVAL;
 124         data->pwm[pwm] = b;
 125         data->psc[pwm] = blink;
 126         return 0;
 127 }
 128
 129 static int pca9532_setpwm(struct i2c_client *client, int pwm)
 130 {
 131         struct pca9532_data *data = i2c_get_clientdata(client);
 132         u8 maxleds = data->chip_info->num_leds;
 133
 134         mutex_lock(&data->update_lock);
 135         i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, pwm),
 136                 data->pwm[pwm]);
 137         i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, pwm),
 138                 data->psc[pwm]);
 139         mutex_unlock(&data->update_lock);
 140         return 0;
 141 }
 142
 143 /* Set LED routing */
 144 static void pca9532_setled(struct pca9532_led *led)
 145 {
 146         struct i2c_client *client = led->client;
 147         struct pca9532_data *data = i2c_get_clientdata(client);
 148         u8 maxleds = data->chip_info->num_leds;
 149         char reg;
 150
 151         mutex_lock(&data->update_lock);
 152         reg = i2c_smbus_read_byte_data(client, LED_REG(maxleds, led->id));
 153         /* zero led bits */
 154         reg = reg & ~(0x3<<LED_NUM(led->id)*2);
 155         /* set the new value */
 156         reg = reg | (led->state << LED_NUM(led->id)*2);
 157         i2c_smbus_write_byte_data(client, LED_REG(maxleds, led->id), reg);
 158         mutex_unlock(&data->update_lock);
 159 }
 160
 161 static void pca9532_set_brightness(struct led_classdev *led_cdev,
 162         enum led_brightness value)
 163 {
 164         int err = 0;
 165         struct pca9532_led *led = ldev_to_led(led_cdev);
 166
 167         if (value == LED_OFF)
 168                 led->state = PCA9532_OFF;
 169         else if (value == LED_FULL)
 170                 led->state = PCA9532_ON;
 171         else {
 172                 led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */
 173                 err = pca9532_calcpwm(led->client, 0, 0, value);
 174                 if (err)
 175                         return; /* XXX: led api doesn't allow error code? */
 176         }
 177         schedule_work(&led->work);
 178 }
 179
 180 static int pca9532_set_blink(struct led_classdev *led_cdev,
 181         unsigned long *delay_on, unsigned long *delay_off)
 182 {
 183         struct pca9532_led *led = ldev_to_led(led_cdev);
 184         struct i2c_client *client = led->client;
 185         int psc;
 186         int err = 0;
 187
 188         if (*delay_on == 0 && *delay_off == 0) {
 189                 /* led subsystem ask us for a blink rate */
 190                 *delay_on = 1000;
 191                 *delay_off = 1000;
 192         }
 193         if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
 194                 return -EINVAL;
 195
 196         /* Thecus specific: only use PSC/PWM 0 */
 197         psc = (*delay_on * 152-1)/1000;
 198         err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
 199         if (err)
 200                 return err;
 201         schedule_work(&led->work);
 202         return 0;
 203 }
 204
 205 static int pca9532_event(struct input_dev *dev, unsigned int type,
 206         unsigned int code, int value)
 207 {
 208         struct pca9532_data *data = input_get_drvdata(dev);
 209
 210         if (!(type == EV_SND && (code == SND_BELL || code == SND_TONE)))
 211                 return -1;
 212
 213         /* XXX: allow different kind of beeps with psc/pwm modifications */
 214         if (value > 1 && value < 32767)
 215                 data->pwm[1] = 127;
 216         else
 217                 data->pwm[1] = 0;
 218
 219         schedule_work(&data->work);
 220
 221         return 0;
 222 }
 223
 224 static void pca9532_input_work(struct work_struct *work)
 225 {
 226         struct pca9532_data *data =
 227                 container_of(work, struct pca9532_data, work);
 228         u8 maxleds = data->chip_info->num_leds;
 229
 230         mutex_lock(&data->update_lock);
 231         i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(maxleds, 1),
 232                 data->pwm[1]);
 233         mutex_unlock(&data->update_lock);
 234 }
 235
 236 static void pca9532_led_work(struct work_struct *work)
 237 {
 238         struct pca9532_led *led;
 239         led = container_of(work, struct pca9532_led, work);
 240         if (led->state == PCA9532_PWM0)
 241                 pca9532_setpwm(led->client, 0);
 242         pca9532_setled(led);
 243 }
 244
 245 #ifdef CONFIG_LEDS_PCA9532_GPIO
 246 static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned offset)
 247 {
 248         struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
 249         struct pca9532_led *led = &data->leds[offset];
 250
 251         if (led->type == PCA9532_TYPE_GPIO)
 252                 return 0;
 253
 254         return -EBUSY;
 255 }
 256
 257 static void pca9532_gpio_set_value(struct gpio_chip *gc, unsigned offset, int val)
 258 {
 259         struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
 260         struct pca9532_led *led = &data->leds[offset];
 261
 262         if (val)
 263                 led->state = PCA9532_ON;
 264         else
 265                 led->state = PCA9532_OFF;
 266
 267         pca9532_setled(led);
 268 }
 269
 270 static int pca9532_gpio_get_value(struct gpio_chip *gc, unsigned offset)
 271 {
 272         struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
 273         unsigned char reg;
 274
 275         reg = i2c_smbus_read_byte_data(data->client, PCA9532_REG_INPUT(offset));
 276
 277         return !!(reg & (1 << (offset % 8)));
 278 }
 279
 280 static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
 281 {
 282         /* To use as input ensure pin is not driven */
 283         pca9532_gpio_set_value(gc, offset, 0);
 284
 285         return 0;
 286 }
 287
 288 static int pca9532_gpio_direction_output(struct gpio_chip *gc, unsigned offset, int val)
 289 {
 290         pca9532_gpio_set_value(gc, offset, val);
 291
 292         return 0;
 293 }
 294 #endif /* CONFIG_LEDS_PCA9532_GPIO */
 295
 296 static int pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
 297 {
 298         int i = n_devs;
 299
 300         if (!data)
 301                 return -EINVAL;
 302
 303         while (--i >= 0) {
 304                 switch (data->leds[i].type) {
 305                 case PCA9532_TYPE_NONE:
 306                 case PCA9532_TYPE_GPIO:
 307                         break;
 308                 case PCA9532_TYPE_LED:
 309                         led_classdev_unregister(&data->leds[i].ldev);
 310                         cancel_work_sync(&data->leds[i].work);
 311                         break;
 312                 case PCA9532_TYPE_N2100_BEEP:
 313                         if (data->idev != NULL) {
 314                                 cancel_work_sync(&data->work);
 315                                 data->idev = NULL;
 316                         }
 317                         break;
 318                 }
 319         }
 320
 321 #ifdef CONFIG_LEDS_PCA9532_GPIO
 322         if (data->gpio.dev)
 323                 gpiochip_remove(&data->gpio);
 324 #endif
 325
 326         return 0;
 327 }
 328
 329 static int pca9532_configure(struct i2c_client *client,
 330         struct pca9532_data *data, struct pca9532_platform_data *pdata)
 331 {
 332         int i, err = 0;
 333         int gpios = 0;
 334         u8 maxleds = data->chip_info->num_leds;
 335
 336         for (i = 0; i < 2; i++) {
 337                 data->pwm[i] = pdata->pwm[i];
 338                 data->psc[i] = pdata->psc[i];
 339                 i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i),
 340                         data->pwm[i]);
 341                 i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i),
 342                         data->psc[i]);
 343         }
 344
 345         for (i = 0; i < data->chip_info->num_leds; i++) {
 346                 struct pca9532_led *led = &data->leds[i];
 347                 struct pca9532_led *pled = &pdata->leds[i];
 348                 led->client = client;
 349                 led->id = i;
 350                 led->type = pled->type;
 351                 switch (led->type) {
 352                 case PCA9532_TYPE_NONE:
 353                         break;
 354                 case PCA9532_TYPE_GPIO:
 355                         gpios++;
 356                         break;
 357                 case PCA9532_TYPE_LED:
 358                         led->state = pled->state;
 359                         led->name = pled->name;
 360                         led->ldev.name = led->name;
 361                         led->ldev.brightness = LED_OFF;
 362                         led->ldev.brightness_set = pca9532_set_brightness;
 363                         led->ldev.blink_set = pca9532_set_blink;
 364                         INIT_WORK(&led->work, pca9532_led_work);
 365                         err = led_classdev_register(&client->dev, &led->ldev);
 366                         if (err < 0) {
 367                                 dev_err(&client->dev,
 368                                         "couldn't register LED %s\n",
 369                                         led->name);
 370                                 goto exit;
 371                         }
 372                         pca9532_setled(led);
 373                         break;
 374                 case PCA9532_TYPE_N2100_BEEP:
 375                         BUG_ON(data->idev);
 376                         led->state = PCA9532_PWM1;
 377                         pca9532_setled(led);
 378                         data->idev = devm_input_allocate_device(&client->dev);
 379                         if (data->idev == NULL) {
 380                                 err = -ENOMEM;
 381                                 goto exit;
 382                         }
 383                         data->idev->name = pled->name;
 384                         data->idev->phys = "i2c/pca9532";
 385                         data->idev->id.bustype = BUS_HOST;
 386                         data->idev->id.vendor = 0x001f;
 387                         data->idev->id.product = 0x0001;
 388                         data->idev->id.version = 0x0100;
 389                         data->idev->evbit[0] = BIT_MASK(EV_SND);
 390                         data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
 391                                                 BIT_MASK(SND_TONE);
 392                         data->idev->event = pca9532_event;
 393                         input_set_drvdata(data->idev, data);
 394                         INIT_WORK(&data->work, pca9532_input_work);
 395                         err = input_register_device(data->idev);
 396                         if (err) {
 397                                 cancel_work_sync(&data->work);
 398                                 data->idev = NULL;
 399                                 goto exit;
 400                         }
 401                         break;
 402                 }
 403         }
 404
 405 #ifdef CONFIG_LEDS_PCA9532_GPIO
 406         if (gpios) {
 407                 data->gpio.label = "gpio-pca9532";
 408                 data->gpio.direction_input = pca9532_gpio_direction_input;
 409                 data->gpio.direction_output = pca9532_gpio_direction_output;
 410                 data->gpio.set = pca9532_gpio_set_value;
 411                 data->gpio.get = pca9532_gpio_get_value;
 412                 data->gpio.request = pca9532_gpio_request_pin;
 413                 data->gpio.can_sleep = 1;
 414                 data->gpio.base = pdata->gpio_base;
 415                 data->gpio.ngpio = data->chip_info->num_leds;
 416                 data->gpio.dev = &client->dev;
 417                 data->gpio.owner = THIS_MODULE;
 418
 419                 err = gpiochip_add(&data->gpio);
 420                 if (err) {
 421                         /* Use data->gpio.dev as a flag for freeing gpiochip */
 422                         data->gpio.dev = NULL;
 423                         dev_warn(&client->dev, "could not add gpiochip\n");
 424                 } else {
 425                         dev_info(&client->dev, "gpios %i...%i\n",
 426                                 data->gpio.base, data->gpio.base +
 427                                 data->gpio.ngpio - 1);
 428                 }
 429         }
 430 #endif
 431
 432         return 0;
 433
 434 exit:
 435         pca9532_destroy_devices(data, i);
 436         return err;
 437 }
 438
 439 static int pca9532_probe(struct i2c_client *client,
 440         const struct i2c_device_id *id)
 441 {
 442         struct pca9532_data *data = i2c_get_clientdata(client);
 443         struct pca9532_platform_data *pca9532_pdata =
 444                         dev_get_platdata(&client->dev);
 445
 446         if (!pca9532_pdata)
 447                 return -EIO;
 448
 449         if (!i2c_check_functionality(client->adapter,
 450                 I2C_FUNC_SMBUS_BYTE_DATA))
 451                 return -EIO;
 452
 453         data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
 454         if (!data)
 455                 return -ENOMEM;
 456
 457         data->chip_info = &pca9532_chip_info_tbl[id->driver_data];
 458
 459         dev_info(&client->dev, "setting platform data\n");
 460         i2c_set_clientdata(client, data);
 461         data->client = client;
 462         mutex_init(&data->update_lock);
 463
 464         return pca9532_configure(client, data, pca9532_pdata);
 465 }
 466
 467 static int pca9532_remove(struct i2c_client *client)
 468 {
 469         struct pca9532_data *data = i2c_get_clientdata(client);
 470         int err;
 471
 472         err = pca9532_destroy_devices(data, data->chip_info->num_leds);
 473         if (err)
 474                 return err;
 475
 476         return 0;
 477 }
 478
 479 module_i2c_driver(pca9532_driver);
 480
 481 MODULE_AUTHOR("Riku Voipio");
 482 MODULE_LICENSE("GPL");
 483 MODULE_DESCRIPTION("PCA 9532 LED dimmer");