drivers/leds/leds-netxbig.c

   1 /*
   2  * leds-netxbig.c - Driver for the 2Big and 5Big Network series LEDs
   3  *
   4  * Copyright (C) 2010 LaCie
   5  *
   6  * Author: Simon Guinot <sguinot@lacie.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/irq.h>
  26 #include <linux/slab.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/gpio.h>
  30 #include <linux/leds.h>
  31 #include <mach/leds-netxbig.h>
  32
  33 /*
  34  * GPIO extension bus.
  35  */
  36
  37 static DEFINE_SPINLOCK(gpio_ext_lock);
  38
  39 static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
  40 {
  41         int pin;
  42
  43         for (pin = 0; pin < gpio_ext->num_addr; pin++)
  44                 gpio_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
  45 }
  46
  47 static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
  48 {
  49         int pin;
  50
  51         for (pin = 0; pin < gpio_ext->num_data; pin++)
  52                 gpio_set_value(gpio_ext->data[pin], (data >> pin) & 1);
  53 }
  54
  55 static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
  56 {
  57         /* Enable select is done on the raising edge. */
  58         gpio_set_value(gpio_ext->enable, 0);
  59         gpio_set_value(gpio_ext->enable, 1);
  60 }
  61
  62 static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
  63                                int addr, int value)
  64 {
  65         unsigned long flags;
  66
  67         spin_lock_irqsave(&gpio_ext_lock, flags);
  68         gpio_ext_set_addr(gpio_ext, addr);
  69         gpio_ext_set_data(gpio_ext, value);
  70         gpio_ext_enable_select(gpio_ext);
  71         spin_unlock_irqrestore(&gpio_ext_lock, flags);
  72 }
  73
  74 static int __devinit gpio_ext_init(struct netxbig_gpio_ext *gpio_ext)
  75 {
  76         int err;
  77         int i;
  78
  79         if (unlikely(!gpio_ext))
  80                 return -EINVAL;
  81
  82         /* Configure address GPIOs. */
  83         for (i = 0; i < gpio_ext->num_addr; i++) {
  84                 err = gpio_request(gpio_ext->addr[i], "GPIO extension addr");
  85                 if (err)
  86                         goto err_free_addr;
  87                 err = gpio_direction_output(gpio_ext->addr[i], 0);
  88                 if (err) {
  89                         gpio_free(gpio_ext->addr[i]);
  90                         goto err_free_addr;
  91                 }
  92         }
  93         /* Configure data GPIOs. */
  94         for (i = 0; i < gpio_ext->num_data; i++) {
  95                 err = gpio_request(gpio_ext->data[i], "GPIO extension data");
  96                 if (err)
  97                         goto err_free_data;
  98                 err = gpio_direction_output(gpio_ext->data[i], 0);
  99                 if (err) {
 100                         gpio_free(gpio_ext->data[i]);
 101                         goto err_free_data;
 102                 }
 103         }
 104         /* Configure "enable select" GPIO. */
 105         err = gpio_request(gpio_ext->enable, "GPIO extension enable");
 106         if (err)
 107                 goto err_free_data;
 108         err = gpio_direction_output(gpio_ext->enable, 0);
 109         if (err) {
 110                 gpio_free(gpio_ext->enable);
 111                 goto err_free_data;
 112         }
 113
 114         return 0;
 115
 116 err_free_data:
 117         for (i = i - 1; i >= 0; i--)
 118                 gpio_free(gpio_ext->data[i]);
 119         i = gpio_ext->num_addr;
 120 err_free_addr:
 121         for (i = i - 1; i >= 0; i--)
 122                 gpio_free(gpio_ext->addr[i]);
 123
 124         return err;
 125 }
 126
 127 static void __devexit gpio_ext_free(struct netxbig_gpio_ext *gpio_ext)
 128 {
 129         int i;
 130
 131         gpio_free(gpio_ext->enable);
 132         for (i = gpio_ext->num_addr - 1; i >= 0; i--)
 133                 gpio_free(gpio_ext->addr[i]);
 134         for (i = gpio_ext->num_data - 1; i >= 0; i--)
 135                 gpio_free(gpio_ext->data[i]);
 136 }
 137
 138 /*
 139  * Class LED driver.
 140  */
 141
 142 struct netxbig_led_data {
 143         struct netxbig_gpio_ext *gpio_ext;
 144         struct led_classdev     cdev;
 145         int                     mode_addr;
 146         int                     *mode_val;
 147         int                     bright_addr;
 148         int                     bright_max;
 149         struct                  netxbig_led_timer *timer;
 150         int                     num_timer;
 151         enum netxbig_led_mode   mode;
 152         int                     sata;
 153         spinlock_t              lock;
 154 };
 155
 156 static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
 157                                       unsigned long delay_on,
 158                                       unsigned long delay_off,
 159                                       struct netxbig_led_timer *timer,
 160                                       int num_timer)
 161 {
 162         int i;
 163
 164         for (i = 0; i < num_timer; i++) {
 165                 if (timer[i].delay_on == delay_on &&
 166                     timer[i].delay_off == delay_off) {
 167                         *mode = timer[i].mode;
 168                         return 0;
 169                 }
 170         }
 171         return -EINVAL;
 172 }
 173
 174 static int netxbig_led_blink_set(struct led_classdev *led_cdev,
 175                                  unsigned long *delay_on,
 176                                  unsigned long *delay_off)
 177 {
 178         struct netxbig_led_data *led_dat =
 179                 container_of(led_cdev, struct netxbig_led_data, cdev);
 180         enum netxbig_led_mode mode;
 181         int mode_val;
 182         int ret;
 183
 184         /* Look for a LED mode with the requested timer frequency. */
 185         ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
 186                                          led_dat->timer, led_dat->num_timer);
 187         if (ret < 0)
 188                 return ret;
 189
 190         mode_val = led_dat->mode_val[mode];
 191         if (mode_val == NETXBIG_LED_INVALID_MODE)
 192                 return -EINVAL;
 193
 194         spin_lock_irq(&led_dat->lock);
 195
 196         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 197         led_dat->mode = mode;
 198
 199         spin_unlock_irq(&led_dat->lock);
 200
 201         return 0;
 202 }
 203
 204 static void netxbig_led_set(struct led_classdev *led_cdev,
 205                             enum led_brightness value)
 206 {
 207         struct netxbig_led_data *led_dat =
 208                 container_of(led_cdev, struct netxbig_led_data, cdev);
 209         enum netxbig_led_mode mode;
 210         int mode_val, bright_val;
 211         int set_brightness = 1;
 212         unsigned long flags;
 213
 214         spin_lock_irqsave(&led_dat->lock, flags);
 215
 216         if (value == LED_OFF) {
 217                 mode = NETXBIG_LED_OFF;
 218                 set_brightness = 0;
 219         } else {
 220                 if (led_dat->sata)
 221                         mode = NETXBIG_LED_SATA;
 222                 else if (led_dat->mode == NETXBIG_LED_OFF)
 223                         mode = NETXBIG_LED_ON;
 224                 else /* Keep 'timer' mode. */
 225                         mode = led_dat->mode;
 226         }
 227         mode_val = led_dat->mode_val[mode];
 228
 229         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 230         led_dat->mode = mode;
 231         /*
 232          * Note that the brightness register is shared between all the
 233          * SATA LEDs. So, change the brightness setting for a single
 234          * SATA LED will affect all the others.
 235          */
 236         if (set_brightness) {
 237                 bright_val = DIV_ROUND_UP(value * led_dat->bright_max,
 238                                           LED_FULL);
 239                 gpio_ext_set_value(led_dat->gpio_ext,
 240                                    led_dat->bright_addr, bright_val);
 241         }
 242
 243         spin_unlock_irqrestore(&led_dat->lock, flags);
 244 }
 245
 246 static ssize_t netxbig_led_sata_store(struct device *dev,
 247                                       struct device_attribute *attr,
 248                                       const char *buff, size_t count)
 249 {
 250         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 251         struct netxbig_led_data *led_dat =
 252                 container_of(led_cdev, struct netxbig_led_data, cdev);
 253         unsigned long enable;
 254         enum netxbig_led_mode mode;
 255         int mode_val;
 256         int ret;
 257
 258         ret = strict_strtoul(buff, 10, &enable);
 259         if (ret < 0)
 260                 return ret;
 261
 262         enable = !!enable;
 263
 264         spin_lock_irq(&led_dat->lock);
 265
 266         if (led_dat->sata == enable) {
 267                 ret = count;
 268                 goto exit_unlock;
 269         }
 270
 271         if (led_dat->mode != NETXBIG_LED_ON &&
 272             led_dat->mode != NETXBIG_LED_SATA)
 273                 mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
 274         else if (enable)
 275                 mode = NETXBIG_LED_SATA;
 276         else
 277                 mode = NETXBIG_LED_ON;
 278
 279         mode_val = led_dat->mode_val[mode];
 280         if (mode_val == NETXBIG_LED_INVALID_MODE) {
 281                 ret = -EINVAL;
 282                 goto exit_unlock;
 283         }
 284
 285         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 286         led_dat->mode = mode;
 287         led_dat->sata = enable;
 288
 289         ret = count;
 290
 291 exit_unlock:
 292         spin_unlock_irq(&led_dat->lock);
 293
 294         return ret;
 295 }
 296
 297 static ssize_t netxbig_led_sata_show(struct device *dev,
 298                                      struct device_attribute *attr, char *buf)
 299 {
 300         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 301         struct netxbig_led_data *led_dat =
 302                 container_of(led_cdev, struct netxbig_led_data, cdev);
 303
 304         return sprintf(buf, "%d\n", led_dat->sata);
 305 }
 306
 307 static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
 308
 309 static void __devexit delete_netxbig_led(struct netxbig_led_data *led_dat)
 310 {
 311         if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
 312                 device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
 313         led_classdev_unregister(&led_dat->cdev);
 314 }
 315
 316 static int __devinit
 317 create_netxbig_led(struct platform_device *pdev,
 318                    struct netxbig_led_data *led_dat,
 319                    const struct netxbig_led *template)
 320 {
 321         struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
 322         int ret;
 323
 324         spin_lock_init(&led_dat->lock);
 325         led_dat->gpio_ext = pdata->gpio_ext;
 326         led_dat->cdev.name = template->name;
 327         led_dat->cdev.default_trigger = template->default_trigger;
 328         led_dat->cdev.blink_set = netxbig_led_blink_set;
 329         led_dat->cdev.brightness_set = netxbig_led_set;
 330         /*
 331          * Because the GPIO extension bus don't allow to read registers
 332          * value, there is no way to probe the LED initial state.
 333          * So, the initial sysfs LED value for the "brightness" and "sata"
 334          * attributes are inconsistent.
 335          *
 336          * Note that the initial LED state can't be reconfigured.
 337          * The reason is that the LED behaviour must stay uniform during
 338          * the whole boot process (bootloader+linux).
 339          */
 340         led_dat->sata = 0;
 341         led_dat->cdev.brightness = LED_OFF;
 342         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 343         led_dat->mode_addr = template->mode_addr;
 344         led_dat->mode_val = template->mode_val;
 345         led_dat->bright_addr = template->bright_addr;
 346         led_dat->bright_max = (1 << pdata->gpio_ext->num_data) - 1;
 347         led_dat->timer = pdata->timer;
 348         led_dat->num_timer = pdata->num_timer;
 349
 350         ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 351         if (ret < 0)
 352                 return ret;
 353
 354         /*
 355          * If available, expose the SATA activity blink capability through
 356          * a "sata" sysfs attribute.
 357          */
 358         if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE) {
 359                 ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
 360                 if (ret)
 361                         led_classdev_unregister(&led_dat->cdev);
 362         }
 363
 364         return ret;
 365 }
 366
 367 static int __devinit netxbig_led_probe(struct platform_device *pdev)
 368 {
 369         struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
 370         struct netxbig_led_data *leds_data;
 371         int i;
 372         int ret;
 373
 374         if (!pdata)
 375                 return -EINVAL;
 376
 377         leds_data = kzalloc(sizeof(struct netxbig_led_data) * pdata->num_leds,
 378                             GFP_KERNEL);
 379         if (!leds_data)
 380                 return -ENOMEM;
 381
 382         ret = gpio_ext_init(pdata->gpio_ext);
 383         if (ret < 0)
 384                 goto err_free_data;
 385
 386         for (i = 0; i < pdata->num_leds; i++) {
 387                 ret = create_netxbig_led(pdev, &leds_data[i], &pdata->leds[i]);
 388                 if (ret < 0)
 389                         goto err_free_leds;
 390         }
 391
 392         platform_set_drvdata(pdev, leds_data);
 393
 394         return 0;
 395
 396 err_free_leds:
 397         for (i = i - 1; i >= 0; i--)
 398                 delete_netxbig_led(&leds_data[i]);
 399
 400         gpio_ext_free(pdata->gpio_ext);
 401 err_free_data:
 402         kfree(leds_data);
 403
 404         return ret;
 405 }
 406
 407 static int __devexit netxbig_led_remove(struct platform_device *pdev)
 408 {
 409         struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
 410         struct netxbig_led_data *leds_data;
 411         int i;
 412
 413         leds_data = platform_get_drvdata(pdev);
 414
 415         for (i = 0; i < pdata->num_leds; i++)
 416                 delete_netxbig_led(&leds_data[i]);
 417
 418         gpio_ext_free(pdata->gpio_ext);
 419         kfree(leds_data);
 420
 421         return 0;
 422 }
 423
 424 static struct platform_driver netxbig_led_driver = {
 425         .probe          = netxbig_led_probe,
 426         .remove         = __devexit_p(netxbig_led_remove),
 427         .driver         = {
 428                 .name   = "leds-netxbig",
 429                 .owner  = THIS_MODULE,
 430         },
 431 };
 432 MODULE_ALIAS("platform:leds-netxbig");
 433
 434 static int __init netxbig_led_init(void)
 435 {
 436         return platform_driver_register(&netxbig_led_driver);
 437 }
 438
 439 static void __exit netxbig_led_exit(void)
 440 {
 441         platform_driver_unregister(&netxbig_led_driver);
 442 }
 443
 444 module_init(netxbig_led_init);
 445 module_exit(netxbig_led_exit);
 446
 447 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 448 MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
 449 MODULE_LICENSE("GPL");