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 static const unsigned short normal_i2c[] = { /*0x60,*/ I2C_CLIENT_END};
  23 I2C_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
  33 struct 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
  43 static int pca9532_probe(struct i2c_client *client,
  44         const struct i2c_device_id *id);
  45 static int pca9532_remove(struct i2c_client *client);
  46
  47 static const struct i2c_device_id pca9532_id[] = {
  48         { "pca9532", 0 },
  49         { }
  50 };
  51
  52 MODULE_DEVICE_TABLE(i2c, pca9532_id);
  53
  54 static 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  * */
  68 static 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
  94 static 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 */
 107 static 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
 123 static 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
 142 static 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
 167 static 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
 186 static 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
 196 static 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
 205 static 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
 278 exit:
 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
 301 static 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
 333 static 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
 360 static int __init pca9532_init(void)
 361 {
 362         return i2c_add_driver(&pca9532_driver);
 363 }
 364
 365 static void __exit pca9532_exit(void)
 366 {
 367         i2c_del_driver(&pca9532_driver);
 368 }
 369
 370 MODULE_AUTHOR("Riku Voipio");
 371 MODULE_LICENSE("GPL");
 372 MODULE_DESCRIPTION("PCA 9532 LED dimmer");
 373
 374 module_init(pca9532_init);
 375 module_exit(pca9532_exit);
 376