drivers/leds/leds-wm831x-status.c

   1 /*
   2  * LED driver for WM831x status LEDs
   3  *
   4  * Copyright(C) 2009 Wolfson Microelectronics PLC.
   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 version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/slab.h>
  16 #include <linux/leds.h>
  17 #include <linux/err.h>
  18 #include <linux/mfd/wm831x/core.h>
  19 #include <linux/mfd/wm831x/pdata.h>
  20 #include <linux/mfd/wm831x/status.h>
  21
  22 struct light_state_t {
  23         unsigned int color;
  24
  25         int mode;
  26         int onms;
  27         int offms;
  28
  29         int brightness;
  30 };
  31
  32 struct wm831x_status {
  33         struct led_classdev cdev;
  34         struct wm831x *wm831x;
  35         struct work_struct work;
  36         struct mutex mutex;
  37
  38         spinlock_t value_lock;
  39         int reg;     /* Control register */
  40         int reg_val; /* Control register value */
  41
  42         int blink;
  43         int blink_time;
  44         int blink_cyc;
  45         int src;
  46         enum led_brightness brightness;
  47 };
  48
  49 #define to_wm831x_status(led_cdev) \
  50         container_of(led_cdev, struct wm831x_status, cdev)
  51
  52 static void wm831x_status_work(struct work_struct *work)
  53 {
  54         struct wm831x_status *led = container_of(work, struct wm831x_status,
  55                                                  work);
  56         unsigned long flags;
  57
  58         mutex_lock(&led->mutex);
  59
  60         led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
  61                           WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
  62
  63         spin_lock_irqsave(&led->value_lock, flags);
  64
  65         led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
  66         if (led->blink) {
  67                 led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;
  68                 led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;
  69                 led->reg_val |= led->blink_cyc;
  70         } else {
  71                 if (led->brightness != LED_OFF)
  72                         led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
  73         }
  74
  75         spin_unlock_irqrestore(&led->value_lock, flags);
  76
  77         wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
  78
  79         mutex_unlock(&led->mutex);
  80 }
  81
  82 static void wm831x_status_set(struct led_classdev *led_cdev,
  83                            enum led_brightness value)
  84 {
  85         struct wm831x_status *led = to_wm831x_status(led_cdev);
  86         unsigned long flags;
  87
  88         spin_lock_irqsave(&led->value_lock, flags);
  89         led->brightness = value;
  90         if (value == LED_OFF)
  91                 led->blink = 0;
  92         schedule_work(&led->work);
  93         spin_unlock_irqrestore(&led->value_lock, flags);
  94 }
  95
  96 static int wm831x_status_blink_set(struct led_classdev *led_cdev,
  97                                    unsigned long *delay_on,
  98                                    unsigned long *delay_off)
  99 {
 100         struct wm831x_status *led = to_wm831x_status(led_cdev);
 101         unsigned long flags;
 102         int ret = 0;
 103
 104         /* Pick some defaults if we've not been given times */
 105         if (*delay_on == 0 && *delay_off == 0) {
 106                 *delay_on = 250;
 107                 *delay_off = 250;
 108         }
 109
 110         spin_lock_irqsave(&led->value_lock, flags);
 111
 112         /* We only have a limited selection of settings, see if we can
 113          * support the configuration we're being given */
 114         switch (*delay_on) {
 115         case 1000:
 116                 led->blink_time = 0;
 117                 break;
 118         case 250:
 119                 led->blink_time = 1;
 120                 break;
 121         case 125:
 122                 led->blink_time = 2;
 123                 break;
 124         case 62:
 125         case 63:
 126                 /* Actually 62.5ms */
 127                 led->blink_time = 3;
 128                 break;
 129         default:
 130                 ret = -EINVAL;
 131                 break;
 132         }
 133
 134         if (ret == 0) {
 135                 switch (*delay_off / *delay_on) {
 136                 case 1:
 137                         led->blink_cyc = 0;
 138                         break;
 139                 case 3:
 140                         led->blink_cyc = 1;
 141                         break;
 142                 case 4:
 143                         led->blink_cyc = 2;
 144                         break;
 145                 case 8:
 146                         led->blink_cyc = 3;
 147                         break;
 148                 default:
 149                         ret = -EINVAL;
 150                         break;
 151                 }
 152         }
 153
 154         if (ret == 0)
 155                 led->blink = 1;
 156         else
 157                 led->blink = 0;
 158
 159         /* Always update; if we fail turn off blinking since we expect
 160          * a software fallback. */
 161         schedule_work(&led->work);
 162
 163         spin_unlock_irqrestore(&led->value_lock, flags);
 164
 165         return ret;
 166 }
 167
 168 static ssize_t wm831x_status_blink_store(struct device *dev,
 169                                        struct device_attribute *attr,
 170                                        const char *buf, size_t size)
 171 {
 172         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 173         struct wm831x_status *led = to_wm831x_status(led_cdev);
 174         struct light_state_t *light_state = NULL;
 175         unsigned long flags;
 176         int ret = 0;
 177     enum led_brightness value;
 178         unsigned int delay_on, delay_off, mode, color;
 179
 180         if (size != sizeof (struct light_state_t)) {
 181                 printk("%s: set led blink err\n", __func__);
 182                 return -1;
 183         }
 184
 185         light_state = (struct light_state_t *)buf;
 186         if (light_state) {
 187                 led->src = 3;
 188
 189                 value = light_state->brightness;
 190                 delay_on = light_state->onms;
 191                 delay_off = light_state->offms;
 192                 mode = light_state->mode;
 193                 color = light_state->color;
 194
 195                 //printk("%s: color = %#x delay_on = %d delya_off = %d brightness = %d mode = %d\n",
 196                 //              __func__, color, delay_on, delay_off, value, mode);
 197                 if (delay_on == 0 && delay_off == 0) {
 198                         delay_on = 250;
 199                         delay_off = 250;
 200                 }
 201
 202                 spin_lock_irqsave(&led->value_lock, flags);
 203
 204                 switch (delay_on) {
 205                 case 1000:
 206                         led->blink_time = 0;
 207                         break;
 208                 case 500:
 209                 case 250:
 210                         led->blink_time = 1;
 211                         break;
 212                 case 125:
 213                         led->blink_time = 2;
 214                         break;
 215                 case 62:
 216                 case 63:
 217                         /* Actually 62.5ms */
 218                         led->blink_time = 3;
 219                         break;
 220                 default:
 221                         ret = -EINVAL;
 222                         break;
 223                 }
 224
 225                 if (ret == 0) {
 226                         switch (delay_off / delay_on) {
 227                         case 1:
 228                                 led->blink_cyc = 0;
 229                                 break;
 230                         case 3:
 231                                 led->blink_cyc = 1;
 232                                 break;
 233                         case 4:
 234                                 led->blink_cyc = 2;
 235                                 break;
 236                         case 8:
 237                                 led->blink_cyc = 3;
 238                                 break;
 239                         default:
 240                                 ret = -EINVAL;
 241                                 break;
 242                         }
 243                 }
 244
 245                 if (ret == 0)
 246                         led->blink = 1;
 247                 else
 248                         led->blink = 0;
 249
 250                 //set led brightness
 251                 led->brightness = mode;
 252                 if (led->brightness == LED_OFF)
 253                         led->blink = 0;
 254
 255                 schedule_work(&led->work);
 256
 257                 spin_unlock_irqrestore(&led->value_lock, flags);
 258         }
 259
 260         return size;
 261 }
 262 static DEVICE_ATTR(blink, 0777, NULL, wm831x_status_blink_store);
 263
 264 static const char *led_src_texts[] = {
 265         "otp",
 266         "power",
 267         "charger",
 268         "soft",
 269 };
 270
 271 static ssize_t wm831x_status_src_show(struct device *dev,
 272                                       struct device_attribute *attr, char *buf)
 273 {
 274         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 275         struct wm831x_status *led = to_wm831x_status(led_cdev);
 276         int i;
 277         ssize_t ret = 0;
 278
 279         mutex_lock(&led->mutex);
 280
 281         for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
 282                 if (i == led->src)
 283                         ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
 284                 else
 285                         ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
 286
 287         mutex_unlock(&led->mutex);
 288
 289         ret += sprintf(&buf[ret], "\n");
 290
 291         return ret;
 292 }
 293
 294 static ssize_t wm831x_status_src_store(struct device *dev,
 295                                        struct device_attribute *attr,
 296                                        const char *buf, size_t size)
 297 {
 298         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 299         struct wm831x_status *led = to_wm831x_status(led_cdev);
 300         char name[20];
 301         int i;
 302         size_t len;
 303
 304         name[sizeof(name) - 1] = '\0';
 305         strncpy(name, buf, sizeof(name) - 1);
 306         len = strlen(name);
 307
 308         if (len && name[len - 1] == '\n')
 309                 name[len - 1] = '\0';
 310
 311         for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
 312                 if (!strcmp(name, led_src_texts[i])) {
 313                         mutex_lock(&led->mutex);
 314
 315                         led->src = i;
 316                         schedule_work(&led->work);
 317
 318                         mutex_unlock(&led->mutex);
 319                 }
 320         }
 321
 322         return size;
 323 }
 324
 325 static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);
 326
 327 static int wm831x_status_probe(struct platform_device *pdev)
 328 {
 329         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 330         struct wm831x_pdata *chip_pdata;
 331         struct wm831x_status_pdata pdata;
 332         struct wm831x_status *drvdata;
 333         struct resource *res;
 334         int id = pdev->id % ARRAY_SIZE(chip_pdata->status);
 335         int ret;
 336
 337         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 338         if (res == NULL) {
 339                 dev_err(&pdev->dev, "No I/O resource\n");
 340                 ret = -EINVAL;
 341                 goto err;
 342         }
 343
 344         drvdata = kzalloc(sizeof(struct wm831x_status), GFP_KERNEL);
 345         if (!drvdata)
 346                 return -ENOMEM;
 347         dev_set_drvdata(&pdev->dev, drvdata);
 348
 349         drvdata->wm831x = wm831x;
 350         drvdata->reg = res->start;
 351
 352         if (wm831x->dev->platform_data)
 353                 chip_pdata = wm831x->dev->platform_data;
 354         else
 355                 chip_pdata = NULL;
 356
 357         memset(&pdata, 0, sizeof(pdata));
 358         if (chip_pdata && chip_pdata->status[id])
 359                 memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
 360         else
 361                 pdata.name = dev_name(&pdev->dev);
 362
 363         mutex_init(&drvdata->mutex);
 364         INIT_WORK(&drvdata->work, wm831x_status_work);
 365         spin_lock_init(&drvdata->value_lock);
 366
 367         /* We cache the configuration register and read startup values
 368          * from it. */
 369         drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
 370         if (drvdata->reg == WM831X_STATUS_LED_2)
 371                 wm831x_reg_write(wm831x, drvdata->reg, 0xc027);
 372
 373         if (drvdata->reg_val & WM831X_LED_MODE_MASK)
 374                 drvdata->brightness = LED_FULL;
 375         else
 376                 drvdata->brightness = LED_OFF;
 377
 378         /* Set a default source if configured, otherwise leave the
 379          * current hardware setting.
 380          */
 381         if (pdata.default_src == WM831X_STATUS_PRESERVE) {
 382                 drvdata->src = drvdata->reg_val;
 383                 drvdata->src &= WM831X_LED_SRC_MASK;
 384                 drvdata->src >>= WM831X_LED_SRC_SHIFT;
 385         } else {
 386                 drvdata->src = pdata.default_src - 1;
 387         }
 388
 389         drvdata->cdev.name = pdata.name;
 390         drvdata->cdev.default_trigger = pdata.default_trigger;
 391         drvdata->cdev.brightness_set = wm831x_status_set;
 392         drvdata->cdev.blink_set = wm831x_status_blink_set;
 393
 394         ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
 395         if (ret < 0) {
 396                 dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
 397                 goto err_led;
 398         }
 399
 400         ret = device_create_file(drvdata->cdev.dev, &dev_attr_blink);
 401         if (ret != 0)
 402                 dev_err(&pdev->dev,
 403                         "LED no blink function: %d\n", ret);
 404
 405         ret = device_create_file(drvdata->cdev.dev, &dev_attr_src);
 406         if (ret != 0)
 407                 dev_err(&pdev->dev,
 408                         "No source control for LED: %d\n", ret);
 409
 410         return 0;
 411
 412 err_led:
 413         led_classdev_unregister(&drvdata->cdev);
 414         kfree(drvdata);
 415 err:
 416         return ret;
 417 }
 418
 419 static int wm831x_status_remove(struct platform_device *pdev)
 420 {
 421         struct wm831x_status *drvdata = platform_get_drvdata(pdev);
 422
 423         device_remove_file(drvdata->cdev.dev, &dev_attr_src);
 424         led_classdev_unregister(&drvdata->cdev);
 425         kfree(drvdata);
 426
 427         return 0;
 428 }
 429
 430 static struct platform_driver wm831x_status_driver = {
 431         .driver = {
 432                    .name = "wm831x-status",
 433                    .owner = THIS_MODULE,
 434                    },
 435         .probe = wm831x_status_probe,
 436         .remove = wm831x_status_remove,
 437 };
 438
 439 static int __devinit wm831x_status_init(void)
 440 {
 441         return platform_driver_register(&wm831x_status_driver);
 442 }
 443 module_init(wm831x_status_init);
 444
 445 static void wm831x_status_exit(void)
 446 {
 447         platform_driver_unregister(&wm831x_status_driver);
 448 }
 449 module_exit(wm831x_status_exit);
 450
 451 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 452 MODULE_DESCRIPTION("WM831x status LED driver");
 453 MODULE_LICENSE("GPL");
 454 MODULE_ALIAS("platform:wm831x-status");