linux/drivers/leds/leds-pca9532.c
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   1/*
   2 * pca9532.c - 16-bit Led dimmer
   3 *
   4 * Copyright (C) 2008 Riku Voipio
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; version 2 of the License.
   9 *
  10 * Datasheet: http://www.nxp.com/acrobat/datasheets/PCA9532_3.pdf
  11 *
  12 */
  13
  14#include <linux/module.h>
  15#include <linux/i2c.h>
  16#include <linux/leds.h>
  17#include <linux/input.h>
  18#include <linux/mutex.h>
  19#include <linux/workqueue.h>
  20#include <linux/leds-pca9532.h>
  21
  22static const unsigned short normal_i2c[] = { /*0x60,*/ I2C_CLIENT_END};
  23I2C_CLIENT_INSMOD_1(pca9532);
  24
  25#define PCA9532_REG_PSC(i) (0x2+(i)*2)
  26#define PCA9532_REG_PWM(i) (0x3+(i)*2)
  27#define PCA9532_REG_LS0  0x6
  28#define LED_REG(led) ((led>>2)+PCA9532_REG_LS0)
  29#define LED_NUM(led) (led & 0x3)
  30
  31#define ldev_to_led(c)       container_of(c, struct pca9532_led, ldev)
  32
  33struct pca9532_data {
  34        struct i2c_client *client;
  35        struct pca9532_led leds[16];
  36        struct mutex update_lock;
  37        struct input_dev    *idev;
  38       struct work_struct work;
  39        u8 pwm[2];
  40        u8 psc[2];
  41};
  42
  43static int pca9532_probe(struct i2c_client *client,
  44        const struct i2c_device_id *id);
  45static int pca9532_remove(struct i2c_client *client);
  46
  47static const struct i2c_device_id pca9532_id[] = {
  48        { "pca9532", 0 },
  49        { }
  50};
  51
  52MODULE_DEVICE_TABLE(i2c, pca9532_id);
  53
  54static struct i2c_driver pca9532_driver = {
  55        .driver = {
  56                .name   = "pca9532",
  57        },
  58        .probe  = pca9532_probe,
  59        .remove = pca9532_remove,
  60        .id_table = pca9532_id,
  61};
  62
  63/* We have two pwm/blinkers, but 16 possible leds to drive. Additionaly,
  64 * the clever Thecus people are using one pwm to drive the beeper. So,
  65 * as a compromise we average one pwm to the values requested by all
  66 * leds that are not ON/OFF.
  67 * */
  68static int pca9532_calcpwm(struct i2c_client *client, int pwm, int blink,
  69        enum led_brightness value)
  70{
  71        int a = 0, b = 0, i = 0;
  72        struct pca9532_data *data = i2c_get_clientdata(client);
  73        for (i = 0; i < 16; i++) {
  74                if (data->leds[i].type == PCA9532_TYPE_LED &&
  75                        data->leds[i].state == PCA9532_PWM0+pwm) {
  76                                a++;
  77                                b += data->leds[i].ldev.brightness;
  78                }
  79        }
  80        if (a == 0) {
  81                dev_err(&client->dev,
  82                "fear of division by zero %d/%d, wanted %d\n",
  83                        b, a, value);
  84                return -EINVAL;
  85        }
  86        b = b/a;
  87        if (b > 0xFF)
  88                return -EINVAL;
  89        data->pwm[pwm] = b;
  90       data->psc[pwm] = blink;
  91       return 0;
  92}
  93
  94static int pca9532_setpwm(struct i2c_client *client, int pwm)
  95{
  96       struct pca9532_data *data = i2c_get_clientdata(client);
  97       mutex_lock(&data->update_lock);
  98        i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(pwm),
  99                data->pwm[pwm]);
 100        i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(pwm),
 101                data->psc[pwm]);
 102        mutex_unlock(&data->update_lock);
 103        return 0;
 104}
 105
 106/* Set LED routing */
 107static void pca9532_setled(struct pca9532_led *led)
 108{
 109        struct i2c_client *client = led->client;
 110        struct pca9532_data *data = i2c_get_clientdata(client);
 111        char reg;
 112
 113        mutex_lock(&data->update_lock);
 114        reg = i2c_smbus_read_byte_data(client, LED_REG(led->id));
 115        /* zero led bits */
 116        reg = reg & ~(0x3<<LED_NUM(led->id)*2);
 117        /* set the new value */
 118        reg = reg | (led->state << LED_NUM(led->id)*2);
 119        i2c_smbus_write_byte_data(client, LED_REG(led->id), reg);
 120        mutex_unlock(&data->update_lock);
 121}
 122
 123static void pca9532_set_brightness(struct led_classdev *led_cdev,
 124        enum led_brightness value)
 125{
 126        int err = 0;
 127        struct pca9532_led *led = ldev_to_led(led_cdev);
 128
 129        if (value == LED_OFF)
 130                led->state = PCA9532_OFF;
 131        else if (value == LED_FULL)
 132                led->state = PCA9532_ON;
 133        else {
 134                led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */
 135               err = pca9532_calcpwm(led->client, 0, 0, value);
 136                if (err)
 137                        return; /* XXX: led api doesn't allow error code? */
 138        }
 139       schedule_work(&led->work);
 140}
 141
 142static int pca9532_set_blink(struct led_classdev *led_cdev,
 143        unsigned long *delay_on, unsigned long *delay_off)
 144{
 145        struct pca9532_led *led = ldev_to_led(led_cdev);
 146        struct i2c_client *client = led->client;
 147        int psc;
 148       int err = 0;
 149
 150        if (*delay_on == 0 && *delay_off == 0) {
 151        /* led subsystem ask us for a blink rate */
 152                *delay_on  = 1000;
 153                *delay_off = 1000;
 154        }
 155        if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
 156                return -EINVAL;
 157
 158        /* Thecus specific: only use PSC/PWM 0 */
 159        psc = (*delay_on * 152-1)/1000;
 160       err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
 161       if (err)
 162               return err;
 163       schedule_work(&led->work);
 164       return 0;
 165}
 166
 167static int pca9532_event(struct input_dev *dev, unsigned int type,
 168        unsigned int code, int value)
 169{
 170        struct pca9532_data *data = input_get_drvdata(dev);
 171
 172        if (!(type == EV_SND && (code == SND_BELL || code == SND_TONE)))
 173                return -1;
 174
 175        /* XXX: allow different kind of beeps with psc/pwm modifications */
 176        if (value > 1 && value < 32767)
 177                data->pwm[1] = 127;
 178        else
 179                data->pwm[1] = 0;
 180
 181       schedule_work(&data->work);
 182
 183       return 0;
 184}
 185
 186static void pca9532_input_work(struct work_struct *work)
 187{
 188       struct pca9532_data *data;
 189       data = container_of(work, struct pca9532_data, work);
 190        mutex_lock(&data->update_lock);
 191        i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(1),
 192                data->pwm[1]);
 193        mutex_unlock(&data->update_lock);
 194}
 195
 196static void pca9532_led_work(struct work_struct *work)
 197{
 198       struct pca9532_led *led;
 199       led = container_of(work, struct pca9532_led, work);
 200       if (led->state == PCA9532_PWM0)
 201               pca9532_setpwm(led->client, 0);
 202       pca9532_setled(led);
 203}
 204
 205static int pca9532_configure(struct i2c_client *client,
 206        struct pca9532_data *data, struct pca9532_platform_data *pdata)
 207{
 208        int i, err = 0;
 209
 210        for (i = 0; i < 2; i++) {
 211                data->pwm[i] = pdata->pwm[i];
 212                data->psc[i] = pdata->psc[i];
 213                i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(i),
 214                        data->pwm[i]);
 215                i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(i),
 216                        data->psc[i]);
 217        }
 218
 219        for (i = 0; i < 16; i++) {
 220                struct pca9532_led *led = &data->leds[i];
 221                struct pca9532_led *pled = &pdata->leds[i];
 222                led->client = client;
 223                led->id = i;
 224                led->type = pled->type;
 225                switch (led->type) {
 226                case PCA9532_TYPE_NONE:
 227                        break;
 228                case PCA9532_TYPE_LED:
 229                        led->state = pled->state;
 230                        led->name =  pled->name;
 231                        led->ldev.name = led->name;
 232                        led->ldev.brightness = LED_OFF;
 233                        led->ldev.brightness_set = pca9532_set_brightness;
 234                        led->ldev.blink_set = pca9532_set_blink;
 235                       INIT_WORK(&led->work, pca9532_led_work);
 236                        err = led_classdev_register(&client->dev, &led->ldev);
 237                        if (err < 0) {
 238                                dev_err(&client->dev,
 239                                        "couldn't register LED %s\n",
 240                                        led->name);
 241                                goto exit;
 242                        }
 243                        pca9532_setled(led);
 244                        break;
 245                case PCA9532_TYPE_N2100_BEEP:
 246                        BUG_ON(data->idev);
 247                        led->state = PCA9532_PWM1;
 248                        pca9532_setled(led);
 249                        data->idev = input_allocate_device();
 250                        if (data->idev == NULL) {
 251                                err = -ENOMEM;
 252                                goto exit;
 253                        }
 254                        data->idev->name = pled->name;
 255                        data->idev->phys = "i2c/pca9532";
 256                        data->idev->id.bustype = BUS_HOST;
 257                        data->idev->id.vendor  = 0x001f;
 258                        data->idev->id.product = 0x0001;
 259                        data->idev->id.version = 0x0100;
 260                        data->idev->evbit[0] = BIT_MASK(EV_SND);
 261                        data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
 262                                                BIT_MASK(SND_TONE);
 263                        data->idev->event = pca9532_event;
 264                        input_set_drvdata(data->idev, data);
 265                       INIT_WORK(&data->work, pca9532_input_work);
 266                        err = input_register_device(data->idev);
 267                        if (err) {
 268                                input_free_device(data->idev);
 269                               cancel_work_sync(&data->work);
 270                                data->idev = NULL;
 271                                goto exit;
 272                        }
 273                        break;
 274                }
 275        }
 276        return 0;
 277
 278exit:
 279        if (i > 0)
 280                for (i = i - 1; i >= 0; i--)
 281                        switch (data->leds[i].type) {
 282                        case PCA9532_TYPE_NONE:
 283                                break;
 284                        case PCA9532_TYPE_LED:
 285                                led_classdev_unregister(&data->leds[i].ldev);
 286                               cancel_work_sync(&data->leds[i].work);
 287                                break;
 288                        case PCA9532_TYPE_N2100_BEEP:
 289                                if (data->idev != NULL) {
 290                                        input_unregister_device(data->idev);
 291                                        input_free_device(data->idev);
 292                                       cancel_work_sync(&data->work);
 293                                        data->idev = NULL;
 294                                }
 295                                break;
 296                        }
 297
 298        return err;
 299}
 300
 301static int pca9532_probe(struct i2c_client *client,
 302        const struct i2c_device_id *id)
 303{
 304        struct pca9532_data *data = i2c_get_clientdata(client);
 305        struct pca9532_platform_data *pca9532_pdata = client->dev.platform_data;
 306        int err;
 307
 308        if (!pca9532_pdata)
 309                return -EIO;
 310
 311        if (!i2c_check_functionality(client->adapter,
 312                I2C_FUNC_SMBUS_BYTE_DATA))
 313                return -EIO;
 314
 315        data = kzalloc(sizeof(*data), GFP_KERNEL);
 316        if (!data)
 317                return -ENOMEM;
 318
 319        dev_info(&client->dev, "setting platform data\n");
 320        i2c_set_clientdata(client, data);
 321        data->client = client;
 322        mutex_init(&data->update_lock);
 323
 324        err = pca9532_configure(client, data, pca9532_pdata);
 325        if (err) {
 326                kfree(data);
 327                i2c_set_clientdata(client, NULL);
 328        }
 329
 330        return err;
 331}
 332
 333static int pca9532_remove(struct i2c_client *client)
 334{
 335        struct pca9532_data *data = i2c_get_clientdata(client);
 336        int i;
 337        for (i = 0; i < 16; i++)
 338                switch (data->leds[i].type) {
 339                case PCA9532_TYPE_NONE:
 340                        break;
 341                case PCA9532_TYPE_LED:
 342                        led_classdev_unregister(&data->leds[i].ldev);
 343                       cancel_work_sync(&data->leds[i].work);
 344                        break;
 345                case PCA9532_TYPE_N2100_BEEP:
 346                        if (data->idev != NULL) {
 347                                input_unregister_device(data->idev);
 348                                input_free_device(data->idev);
 349                               cancel_work_sync(&data->work);
 350                                data->idev = NULL;
 351                        }
 352                        break;
 353                }
 354
 355        kfree(data);
 356        i2c_set_clientdata(client, NULL);
 357        return 0;
 358}
 359
 360static int __init pca9532_init(void)
 361{
 362        return i2c_add_driver(&pca9532_driver);
 363}
 364
 365static void __exit pca9532_exit(void)
 366{
 367        i2c_del_driver(&pca9532_driver);
 368}
 369
 370MODULE_AUTHOR("Riku Voipio");
 371MODULE_LICENSE("GPL");
 372MODULE_DESCRIPTION("PCA 9532 LED dimmer");
 373
 374module_init(pca9532_init);
 375module_exit(pca9532_exit);
 376
 377