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