linux/drivers/leds/leds-pca9532.c
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   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
  35struct pca9532_chip_info {
  36        u8      num_leds;
  37};
  38
  39struct 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
  53static int pca9532_probe(struct i2c_client *client,
  54        const struct i2c_device_id *id);
  55static int pca9532_remove(struct i2c_client *client);
  56
  57enum {
  58        pca9530,
  59        pca9531,
  60        pca9532,
  61        pca9533,
  62};
  63
  64static const struct i2c_device_id pca9532_id[] = {
  65        { "pca9530", pca9530 },
  66        { "pca9531", pca9531 },
  67        { "pca9532", pca9532 },
  68        { "pca9533", pca9533 },
  69        { }
  70};
  71
  72MODULE_DEVICE_TABLE(i2c, pca9532_id);
  73
  74static 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
  89static 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 * */
 103static 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
 129static 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 */
 144static 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
 161static 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
 180static 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
 205static 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
 224static 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
 236static 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
 246static 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
 257static 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
 270static 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
 280static 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
 288static 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
 296static 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                                input_unregister_device(data->idev);
 315                                cancel_work_sync(&data->work);
 316                                data->idev = NULL;
 317                        }
 318                        break;
 319                }
 320        }
 321
 322#ifdef CONFIG_LEDS_PCA9532_GPIO
 323        if (data->gpio.dev) {
 324                int err = gpiochip_remove(&data->gpio);
 325                if (err) {
 326                        dev_err(&data->client->dev, "%s failed, %d\n",
 327                                                "gpiochip_remove()", err);
 328                        return err;
 329                }
 330        }
 331#endif
 332
 333        return 0;
 334}
 335
 336static int pca9532_configure(struct i2c_client *client,
 337        struct pca9532_data *data, struct pca9532_platform_data *pdata)
 338{
 339        int i, err = 0;
 340        int gpios = 0;
 341        u8 maxleds = data->chip_info->num_leds;
 342
 343        for (i = 0; i < 2; i++) {
 344                data->pwm[i] = pdata->pwm[i];
 345                data->psc[i] = pdata->psc[i];
 346                i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i),
 347                        data->pwm[i]);
 348                i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i),
 349                        data->psc[i]);
 350        }
 351
 352        for (i = 0; i < data->chip_info->num_leds; i++) {
 353                struct pca9532_led *led = &data->leds[i];
 354                struct pca9532_led *pled = &pdata->leds[i];
 355                led->client = client;
 356                led->id = i;
 357                led->type = pled->type;
 358                switch (led->type) {
 359                case PCA9532_TYPE_NONE:
 360                        break;
 361                case PCA9532_TYPE_GPIO:
 362                        gpios++;
 363                        break;
 364                case PCA9532_TYPE_LED:
 365                        led->state = pled->state;
 366                        led->name = pled->name;
 367                        led->ldev.name = led->name;
 368                        led->ldev.brightness = LED_OFF;
 369                        led->ldev.brightness_set = pca9532_set_brightness;
 370                        led->ldev.blink_set = pca9532_set_blink;
 371                        INIT_WORK(&led->work, pca9532_led_work);
 372                        err = led_classdev_register(&client->dev, &led->ldev);
 373                        if (err < 0) {
 374                                dev_err(&client->dev,
 375                                        "couldn't register LED %s\n",
 376                                        led->name);
 377                                goto exit;
 378                        }
 379                        pca9532_setled(led);
 380                        break;
 381                case PCA9532_TYPE_N2100_BEEP:
 382                        BUG_ON(data->idev);
 383                        led->state = PCA9532_PWM1;
 384                        pca9532_setled(led);
 385                        data->idev = input_allocate_device();
 386                        if (data->idev == NULL) {
 387                                err = -ENOMEM;
 388                                goto exit;
 389                        }
 390                        data->idev->name = pled->name;
 391                        data->idev->phys = "i2c/pca9532";
 392                        data->idev->id.bustype = BUS_HOST;
 393                        data->idev->id.vendor = 0x001f;
 394                        data->idev->id.product = 0x0001;
 395                        data->idev->id.version = 0x0100;
 396                        data->idev->evbit[0] = BIT_MASK(EV_SND);
 397                        data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
 398                                                BIT_MASK(SND_TONE);
 399                        data->idev->event = pca9532_event;
 400                        input_set_drvdata(data->idev, data);
 401                        INIT_WORK(&data->work, pca9532_input_work);
 402                        err = input_register_device(data->idev);
 403                        if (err) {
 404                                input_free_device(data->idev);
 405                                cancel_work_sync(&data->work);
 406                                data->idev = NULL;
 407                                goto exit;
 408                        }
 409                        break;
 410                }
 411        }
 412
 413#ifdef CONFIG_LEDS_PCA9532_GPIO
 414        if (gpios) {
 415                data->gpio.label = "gpio-pca9532";
 416                data->gpio.direction_input = pca9532_gpio_direction_input;
 417                data->gpio.direction_output = pca9532_gpio_direction_output;
 418                data->gpio.set = pca9532_gpio_set_value;
 419                data->gpio.get = pca9532_gpio_get_value;
 420                data->gpio.request = pca9532_gpio_request_pin;
 421                data->gpio.can_sleep = 1;
 422                data->gpio.base = pdata->gpio_base;
 423                data->gpio.ngpio = data->chip_info->num_leds;
 424                data->gpio.dev = &client->dev;
 425                data->gpio.owner = THIS_MODULE;
 426
 427                err = gpiochip_add(&data->gpio);
 428                if (err) {
 429                        /* Use data->gpio.dev as a flag for freeing gpiochip */
 430                        data->gpio.dev = NULL;
 431                        dev_warn(&client->dev, "could not add gpiochip\n");
 432                } else {
 433                        dev_info(&client->dev, "gpios %i...%i\n",
 434                                data->gpio.base, data->gpio.base +
 435                                data->gpio.ngpio - 1);
 436                }
 437        }
 438#endif
 439
 440        return 0;
 441
 442exit:
 443        pca9532_destroy_devices(data, i);
 444        return err;
 445}
 446
 447static int pca9532_probe(struct i2c_client *client,
 448        const struct i2c_device_id *id)
 449{
 450        struct pca9532_data *data = i2c_get_clientdata(client);
 451        struct pca9532_platform_data *pca9532_pdata = client->dev.platform_data;
 452
 453        if (!pca9532_pdata)
 454                return -EIO;
 455
 456        if (!i2c_check_functionality(client->adapter,
 457                I2C_FUNC_SMBUS_BYTE_DATA))
 458                return -EIO;
 459
 460        data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
 461        if (!data)
 462                return -ENOMEM;
 463
 464        data->chip_info = &pca9532_chip_info_tbl[id->driver_data];
 465
 466        dev_info(&client->dev, "setting platform data\n");
 467        i2c_set_clientdata(client, data);
 468        data->client = client;
 469        mutex_init(&data->update_lock);
 470
 471        return pca9532_configure(client, data, pca9532_pdata);
 472}
 473
 474static int pca9532_remove(struct i2c_client *client)
 475{
 476        struct pca9532_data *data = i2c_get_clientdata(client);
 477        int err;
 478
 479        err = pca9532_destroy_devices(data, data->chip_info->num_leds);
 480        if (err)
 481                return err;
 482
 483        return 0;
 484}
 485
 486module_i2c_driver(pca9532_driver);
 487
 488MODULE_AUTHOR("Riku Voipio");
 489MODULE_LICENSE("GPL");
 490MODULE_DESCRIPTION("PCA 9532 LED dimmer");
 491
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