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/irq.h>
  25 #include <linux/slab.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/gpio.h>
  29 #include <linux/leds.h>
  30 #include <linux/platform_data/leds-kirkwood-netxbig.h>
  31
  32 /*
  33  * GPIO extension bus.
  34  */
  35
  36 static DEFINE_SPINLOCK(gpio_ext_lock);
  37
  38 static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
  39 {
  40         int pin;
  41
  42         for (pin = 0; pin < gpio_ext->num_addr; pin++)
  43                 gpio_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
  44 }
  45
  46 static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
  47 {
  48         int pin;
  49
  50         for (pin = 0; pin < gpio_ext->num_data; pin++)
  51                 gpio_set_value(gpio_ext->data[pin], (data >> pin) & 1);
  52 }
  53
  54 static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
  55 {
  56         /* Enable select is done on the raising edge. */
  57         gpio_set_value(gpio_ext->enable, 0);
  58         gpio_set_value(gpio_ext->enable, 1);
  59 }
  60
  61 static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
  62                                int addr, int value)
  63 {
  64         unsigned long flags;
  65
  66         spin_lock_irqsave(&gpio_ext_lock, flags);
  67         gpio_ext_set_addr(gpio_ext, addr);
  68         gpio_ext_set_data(gpio_ext, value);
  69         gpio_ext_enable_select(gpio_ext);
  70         spin_unlock_irqrestore(&gpio_ext_lock, flags);
  71 }
  72
  73 static int gpio_ext_init(struct netxbig_gpio_ext *gpio_ext)
  74 {
  75         int err;
  76         int i;
  77
  78         if (unlikely(!gpio_ext))
  79                 return -EINVAL;
  80
  81         /* Configure address GPIOs. */
  82         for (i = 0; i < gpio_ext->num_addr; i++) {
  83                 err = gpio_request_one(gpio_ext->addr[i], GPIOF_OUT_INIT_LOW,
  84                                        "GPIO extension addr");
  85                 if (err)
  86                         goto err_free_addr;
  87         }
  88         /* Configure data GPIOs. */
  89         for (i = 0; i < gpio_ext->num_data; i++) {
  90                 err = gpio_request_one(gpio_ext->data[i], GPIOF_OUT_INIT_LOW,
  91                                    "GPIO extension data");
  92                 if (err)
  93                         goto err_free_data;
  94         }
  95         /* Configure "enable select" GPIO. */
  96         err = gpio_request_one(gpio_ext->enable, GPIOF_OUT_INIT_LOW,
  97                                "GPIO extension enable");
  98         if (err)
  99                 goto err_free_data;
 100
 101         return 0;
 102
 103 err_free_data:
 104         for (i = i - 1; i >= 0; i--)
 105                 gpio_free(gpio_ext->data[i]);
 106         i = gpio_ext->num_addr;
 107 err_free_addr:
 108         for (i = i - 1; i >= 0; i--)
 109                 gpio_free(gpio_ext->addr[i]);
 110
 111         return err;
 112 }
 113
 114 static void gpio_ext_free(struct netxbig_gpio_ext *gpio_ext)
 115 {
 116         int i;
 117
 118         gpio_free(gpio_ext->enable);
 119         for (i = gpio_ext->num_addr - 1; i >= 0; i--)
 120                 gpio_free(gpio_ext->addr[i]);
 121         for (i = gpio_ext->num_data - 1; i >= 0; i--)
 122                 gpio_free(gpio_ext->data[i]);
 123 }
 124
 125 /*
 126  * Class LED driver.
 127  */
 128
 129 struct netxbig_led_data {
 130         struct netxbig_gpio_ext *gpio_ext;
 131         struct led_classdev     cdev;
 132         int                     mode_addr;
 133         int                     *mode_val;
 134         int                     bright_addr;
 135         int                     bright_max;
 136         struct                  netxbig_led_timer *timer;
 137         int                     num_timer;
 138         enum netxbig_led_mode   mode;
 139         int                     sata;
 140         spinlock_t              lock;
 141 };
 142
 143 static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
 144                                       unsigned long delay_on,
 145                                       unsigned long delay_off,
 146                                       struct netxbig_led_timer *timer,
 147                                       int num_timer)
 148 {
 149         int i;
 150
 151         for (i = 0; i < num_timer; i++) {
 152                 if (timer[i].delay_on == delay_on &&
 153                     timer[i].delay_off == delay_off) {
 154                         *mode = timer[i].mode;
 155                         return 0;
 156                 }
 157         }
 158         return -EINVAL;
 159 }
 160
 161 static int netxbig_led_blink_set(struct led_classdev *led_cdev,
 162                                  unsigned long *delay_on,
 163                                  unsigned long *delay_off)
 164 {
 165         struct netxbig_led_data *led_dat =
 166                 container_of(led_cdev, struct netxbig_led_data, cdev);
 167         enum netxbig_led_mode mode;
 168         int mode_val;
 169         int ret;
 170
 171         /* Look for a LED mode with the requested timer frequency. */
 172         ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
 173                                          led_dat->timer, led_dat->num_timer);
 174         if (ret < 0)
 175                 return ret;
 176
 177         mode_val = led_dat->mode_val[mode];
 178         if (mode_val == NETXBIG_LED_INVALID_MODE)
 179                 return -EINVAL;
 180
 181         spin_lock_irq(&led_dat->lock);
 182
 183         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 184         led_dat->mode = mode;
 185
 186         spin_unlock_irq(&led_dat->lock);
 187
 188         return 0;
 189 }
 190
 191 static void netxbig_led_set(struct led_classdev *led_cdev,
 192                             enum led_brightness value)
 193 {
 194         struct netxbig_led_data *led_dat =
 195                 container_of(led_cdev, struct netxbig_led_data, cdev);
 196         enum netxbig_led_mode mode;
 197         int mode_val, bright_val;
 198         int set_brightness = 1;
 199         unsigned long flags;
 200
 201         spin_lock_irqsave(&led_dat->lock, flags);
 202
 203         if (value == LED_OFF) {
 204                 mode = NETXBIG_LED_OFF;
 205                 set_brightness = 0;
 206         } else {
 207                 if (led_dat->sata)
 208                         mode = NETXBIG_LED_SATA;
 209                 else if (led_dat->mode == NETXBIG_LED_OFF)
 210                         mode = NETXBIG_LED_ON;
 211                 else /* Keep 'timer' mode. */
 212                         mode = led_dat->mode;
 213         }
 214         mode_val = led_dat->mode_val[mode];
 215
 216         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 217         led_dat->mode = mode;
 218         /*
 219          * Note that the brightness register is shared between all the
 220          * SATA LEDs. So, change the brightness setting for a single
 221          * SATA LED will affect all the others.
 222          */
 223         if (set_brightness) {
 224                 bright_val = DIV_ROUND_UP(value * led_dat->bright_max,
 225                                           LED_FULL);
 226                 gpio_ext_set_value(led_dat->gpio_ext,
 227                                    led_dat->bright_addr, bright_val);
 228         }
 229
 230         spin_unlock_irqrestore(&led_dat->lock, flags);
 231 }
 232
 233 static ssize_t netxbig_led_sata_store(struct device *dev,
 234                                       struct device_attribute *attr,
 235                                       const char *buff, size_t count)
 236 {
 237         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 238         struct netxbig_led_data *led_dat =
 239                 container_of(led_cdev, struct netxbig_led_data, cdev);
 240         unsigned long enable;
 241         enum netxbig_led_mode mode;
 242         int mode_val;
 243         int ret;
 244
 245         ret = kstrtoul(buff, 10, &enable);
 246         if (ret < 0)
 247                 return ret;
 248
 249         enable = !!enable;
 250
 251         spin_lock_irq(&led_dat->lock);
 252
 253         if (led_dat->sata == enable) {
 254                 ret = count;
 255                 goto exit_unlock;
 256         }
 257
 258         if (led_dat->mode != NETXBIG_LED_ON &&
 259             led_dat->mode != NETXBIG_LED_SATA)
 260                 mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
 261         else if (enable)
 262                 mode = NETXBIG_LED_SATA;
 263         else
 264                 mode = NETXBIG_LED_ON;
 265
 266         mode_val = led_dat->mode_val[mode];
 267         if (mode_val == NETXBIG_LED_INVALID_MODE) {
 268                 ret = -EINVAL;
 269                 goto exit_unlock;
 270         }
 271
 272         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 273         led_dat->mode = mode;
 274         led_dat->sata = enable;
 275
 276         ret = count;
 277
 278 exit_unlock:
 279         spin_unlock_irq(&led_dat->lock);
 280
 281         return ret;
 282 }
 283
 284 static ssize_t netxbig_led_sata_show(struct device *dev,
 285                                      struct device_attribute *attr, char *buf)
 286 {
 287         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 288         struct netxbig_led_data *led_dat =
 289                 container_of(led_cdev, struct netxbig_led_data, cdev);
 290
 291         return sprintf(buf, "%d\n", led_dat->sata);
 292 }
 293
 294 static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
 295
 296 static struct attribute *netxbig_led_attrs[] = {
 297         &dev_attr_sata.attr,
 298         NULL
 299 };
 300 ATTRIBUTE_GROUPS(netxbig_led);
 301
 302 static void delete_netxbig_led(struct netxbig_led_data *led_dat)
 303 {
 304         led_classdev_unregister(&led_dat->cdev);
 305 }
 306
 307 static int
 308 create_netxbig_led(struct platform_device *pdev,
 309                    struct netxbig_led_data *led_dat,
 310                    const struct netxbig_led *template)
 311 {
 312         struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 313
 314         spin_lock_init(&led_dat->lock);
 315         led_dat->gpio_ext = pdata->gpio_ext;
 316         led_dat->cdev.name = template->name;
 317         led_dat->cdev.default_trigger = template->default_trigger;
 318         led_dat->cdev.blink_set = netxbig_led_blink_set;
 319         led_dat->cdev.brightness_set = netxbig_led_set;
 320         /*
 321          * Because the GPIO extension bus don't allow to read registers
 322          * value, there is no way to probe the LED initial state.
 323          * So, the initial sysfs LED value for the "brightness" and "sata"
 324          * attributes are inconsistent.
 325          *
 326          * Note that the initial LED state can't be reconfigured.
 327          * The reason is that the LED behaviour must stay uniform during
 328          * the whole boot process (bootloader+linux).
 329          */
 330         led_dat->sata = 0;
 331         led_dat->cdev.brightness = LED_OFF;
 332         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 333         led_dat->mode_addr = template->mode_addr;
 334         led_dat->mode_val = template->mode_val;
 335         led_dat->bright_addr = template->bright_addr;
 336         led_dat->bright_max = (1 << pdata->gpio_ext->num_data) - 1;
 337         led_dat->timer = pdata->timer;
 338         led_dat->num_timer = pdata->num_timer;
 339         /*
 340          * If available, expose the SATA activity blink capability through
 341          * a "sata" sysfs attribute.
 342          */
 343         if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
 344                 led_dat->cdev.groups = netxbig_led_groups;
 345
 346         return led_classdev_register(&pdev->dev, &led_dat->cdev);
 347 }
 348
 349 static int netxbig_led_probe(struct platform_device *pdev)
 350 {
 351         struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 352         struct netxbig_led_data *leds_data;
 353         int i;
 354         int ret;
 355
 356         if (!pdata)
 357                 return -EINVAL;
 358
 359         leds_data = devm_kzalloc(&pdev->dev,
 360                 sizeof(struct netxbig_led_data) * pdata->num_leds, GFP_KERNEL);
 361         if (!leds_data)
 362                 return -ENOMEM;
 363
 364         ret = gpio_ext_init(pdata->gpio_ext);
 365         if (ret < 0)
 366                 return ret;
 367
 368         for (i = 0; i < pdata->num_leds; i++) {
 369                 ret = create_netxbig_led(pdev, &leds_data[i], &pdata->leds[i]);
 370                 if (ret < 0)
 371                         goto err_free_leds;
 372         }
 373
 374         platform_set_drvdata(pdev, leds_data);
 375
 376         return 0;
 377
 378 err_free_leds:
 379         for (i = i - 1; i >= 0; i--)
 380                 delete_netxbig_led(&leds_data[i]);
 381
 382         gpio_ext_free(pdata->gpio_ext);
 383         return ret;
 384 }
 385
 386 static int netxbig_led_remove(struct platform_device *pdev)
 387 {
 388         struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 389         struct netxbig_led_data *leds_data;
 390         int i;
 391
 392         leds_data = platform_get_drvdata(pdev);
 393
 394         for (i = 0; i < pdata->num_leds; i++)
 395                 delete_netxbig_led(&leds_data[i]);
 396
 397         gpio_ext_free(pdata->gpio_ext);
 398
 399         return 0;
 400 }
 401
 402 static struct platform_driver netxbig_led_driver = {
 403         .probe          = netxbig_led_probe,
 404         .remove         = netxbig_led_remove,
 405         .driver         = {
 406                 .name   = "leds-netxbig",
 407         },
 408 };
 409
 410 module_platform_driver(netxbig_led_driver);
 411
 412 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 413 MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
 414 MODULE_LICENSE("GPL");
 415 MODULE_ALIAS("platform:leds-netxbig");