drivers/leds/leds-pca9532.c

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