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/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
  31 struct 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
  41 static int pca9532_probe(struct i2c_client *client,
  42         const struct i2c_device_id *id);
  43 static int pca9532_remove(struct i2c_client *client);
  44
  45 static const struct i2c_device_id pca9532_id[] = {
  46         { "pca9532", 0 },
  47         { }
  48 };
  49
  50 MODULE_DEVICE_TABLE(i2c, pca9532_id);
  51
  52 static 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  * */
  66 static 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
  92 static 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 */
 105 static 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
 121 static 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
 140 static 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
 165 static 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
 184 static 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
 194 static 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
 203 static void pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
 204 {
 205         int i = n_devs;
 206
 207         if (!data)
 208                 return;
 209
 210         while (--i >= 0) {
 211                 switch (data->leds[i].type) {
 212                 case PCA9532_TYPE_NONE:
 213                         break;
 214                 case PCA9532_TYPE_LED:
 215                         led_classdev_unregister(&data->leds[i].ldev);
 216                         cancel_work_sync(&data->leds[i].work);
 217                         break;
 218                 case PCA9532_TYPE_N2100_BEEP:
 219                         if (data->idev != NULL) {
 220                                 input_unregister_device(data->idev);
 221                                 cancel_work_sync(&data->work);
 222                                 data->idev = NULL;
 223                         }
 224                         break;
 225                 }
 226         }
 227 }
 228
 229 static int pca9532_configure(struct i2c_client *client,
 230         struct pca9532_data *data, struct pca9532_platform_data *pdata)
 231 {
 232         int i, err = 0;
 233
 234         for (i = 0; i < 2; i++) {
 235                 data->pwm[i] = pdata->pwm[i];
 236                 data->psc[i] = pdata->psc[i];
 237                 i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(i),
 238                         data->pwm[i]);
 239                 i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(i),
 240                         data->psc[i]);
 241         }
 242
 243         for (i = 0; i < 16; i++) {
 244                 struct pca9532_led *led = &data->leds[i];
 245                 struct pca9532_led *pled = &pdata->leds[i];
 246                 led->client = client;
 247                 led->id = i;
 248                 led->type = pled->type;
 249                 switch (led->type) {
 250                 case PCA9532_TYPE_NONE:
 251                         break;
 252                 case PCA9532_TYPE_LED:
 253                         led->state = pled->state;
 254                         led->name = pled->name;
 255                         led->ldev.name = led->name;
 256                         led->ldev.brightness = LED_OFF;
 257                         led->ldev.brightness_set = pca9532_set_brightness;
 258                         led->ldev.blink_set = pca9532_set_blink;
 259                         INIT_WORK(&led->work, pca9532_led_work);
 260                         err = led_classdev_register(&client->dev, &led->ldev);
 261                         if (err < 0) {
 262                                 dev_err(&client->dev,
 263                                         "couldn't register LED %s\n",
 264                                         led->name);
 265                                 goto exit;
 266                         }
 267                         pca9532_setled(led);
 268                         break;
 269                 case PCA9532_TYPE_N2100_BEEP:
 270                         BUG_ON(data->idev);
 271                         led->state = PCA9532_PWM1;
 272                         pca9532_setled(led);
 273                         data->idev = input_allocate_device();
 274                         if (data->idev == NULL) {
 275                                 err = -ENOMEM;
 276                                 goto exit;
 277                         }
 278                         data->idev->name = pled->name;
 279                         data->idev->phys = "i2c/pca9532";
 280                         data->idev->id.bustype = BUS_HOST;
 281                         data->idev->id.vendor = 0x001f;
 282                         data->idev->id.product = 0x0001;
 283                         data->idev->id.version = 0x0100;
 284                         data->idev->evbit[0] = BIT_MASK(EV_SND);
 285                         data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
 286                                                 BIT_MASK(SND_TONE);
 287                         data->idev->event = pca9532_event;
 288                         input_set_drvdata(data->idev, data);
 289                         INIT_WORK(&data->work, pca9532_input_work);
 290                         err = input_register_device(data->idev);
 291                         if (err) {
 292                                 input_free_device(data->idev);
 293                                 cancel_work_sync(&data->work);
 294                                 data->idev = NULL;
 295                                 goto exit;
 296                         }
 297                         break;
 298                 }
 299         }
 300         return 0;
 301
 302 exit:
 303         pca9532_destroy_devices(data, i);
 304         return err;
 305 }
 306
 307 static int pca9532_probe(struct i2c_client *client,
 308         const struct i2c_device_id *id)
 309 {
 310         struct pca9532_data *data = i2c_get_clientdata(client);
 311         struct pca9532_platform_data *pca9532_pdata = client->dev.platform_data;
 312         int err;
 313
 314         if (!pca9532_pdata)
 315                 return -EIO;
 316
 317         if (!i2c_check_functionality(client->adapter,
 318                 I2C_FUNC_SMBUS_BYTE_DATA))
 319                 return -EIO;
 320
 321         data = kzalloc(sizeof(*data), GFP_KERNEL);
 322         if (!data)
 323                 return -ENOMEM;
 324
 325         dev_info(&client->dev, "setting platform data\n");
 326         i2c_set_clientdata(client, data);
 327         data->client = client;
 328         mutex_init(&data->update_lock);
 329
 330         err = pca9532_configure(client, data, pca9532_pdata);
 331         if (err)
 332                 kfree(data);
 333
 334         return err;
 335 }
 336
 337 static int pca9532_remove(struct i2c_client *client)
 338 {
 339         struct pca9532_data *data = i2c_get_clientdata(client);
 340         pca9532_destroy_devices(data, 16);
 341         kfree(data);
 342         return 0;
 343 }
 344
 345 static int __init pca9532_init(void)
 346 {
 347         return i2c_add_driver(&pca9532_driver);
 348 }
 349
 350 static void __exit pca9532_exit(void)
 351 {
 352         i2c_del_driver(&pca9532_driver);
 353 }
 354
 355 MODULE_AUTHOR("Riku Voipio");
 356 MODULE_LICENSE("GPL");
 357 MODULE_DESCRIPTION("PCA 9532 LED dimmer");
 358
 359 module_init(pca9532_init);
 360 module_exit(pca9532_exit);
 361