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 <linux/platform_data/leds-kirkwood-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 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_one(gpio_ext->addr[i], GPIOF_OUT_INIT_LOW,
  85                                        "GPIO extension addr");
  86                 if (err)
  87                         goto err_free_addr;
  88         }
  89         /* Configure data GPIOs. */
  90         for (i = 0; i < gpio_ext->num_data; i++) {
  91                 err = gpio_request_one(gpio_ext->data[i], GPIOF_OUT_INIT_LOW,
  92                                    "GPIO extension data");
  93                 if (err)
  94                         goto err_free_data;
  95         }
  96         /* Configure "enable select" GPIO. */
  97         err = gpio_request_one(gpio_ext->enable, GPIOF_OUT_INIT_LOW,
  98                                "GPIO extension enable");
  99         if (err)
 100                 goto err_free_data;
 101
 102         return 0;
 103
 104 err_free_data:
 105         for (i = i - 1; i >= 0; i--)
 106                 gpio_free(gpio_ext->data[i]);
 107         i = gpio_ext->num_addr;
 108 err_free_addr:
 109         for (i = i - 1; i >= 0; i--)
 110                 gpio_free(gpio_ext->addr[i]);
 111
 112         return err;
 113 }
 114
 115 static void gpio_ext_free(struct netxbig_gpio_ext *gpio_ext)
 116 {
 117         int i;
 118
 119         gpio_free(gpio_ext->enable);
 120         for (i = gpio_ext->num_addr - 1; i >= 0; i--)
 121                 gpio_free(gpio_ext->addr[i]);
 122         for (i = gpio_ext->num_data - 1; i >= 0; i--)
 123                 gpio_free(gpio_ext->data[i]);
 124 }
 125
 126 /*
 127  * Class LED driver.
 128  */
 129
 130 struct netxbig_led_data {
 131         struct netxbig_gpio_ext *gpio_ext;
 132         struct led_classdev     cdev;
 133         int                     mode_addr;
 134         int                     *mode_val;
 135         int                     bright_addr;
 136         int                     bright_max;
 137         struct                  netxbig_led_timer *timer;
 138         int                     num_timer;
 139         enum netxbig_led_mode   mode;
 140         int                     sata;
 141         spinlock_t              lock;
 142 };
 143
 144 static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
 145                                       unsigned long delay_on,
 146                                       unsigned long delay_off,
 147                                       struct netxbig_led_timer *timer,
 148                                       int num_timer)
 149 {
 150         int i;
 151
 152         for (i = 0; i < num_timer; i++) {
 153                 if (timer[i].delay_on == delay_on &&
 154                     timer[i].delay_off == delay_off) {
 155                         *mode = timer[i].mode;
 156                         return 0;
 157                 }
 158         }
 159         return -EINVAL;
 160 }
 161
 162 static int netxbig_led_blink_set(struct led_classdev *led_cdev,
 163                                  unsigned long *delay_on,
 164                                  unsigned long *delay_off)
 165 {
 166         struct netxbig_led_data *led_dat =
 167                 container_of(led_cdev, struct netxbig_led_data, cdev);
 168         enum netxbig_led_mode mode;
 169         int mode_val;
 170         int ret;
 171
 172         /* Look for a LED mode with the requested timer frequency. */
 173         ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
 174                                          led_dat->timer, led_dat->num_timer);
 175         if (ret < 0)
 176                 return ret;
 177
 178         mode_val = led_dat->mode_val[mode];
 179         if (mode_val == NETXBIG_LED_INVALID_MODE)
 180                 return -EINVAL;
 181
 182         spin_lock_irq(&led_dat->lock);
 183
 184         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 185         led_dat->mode = mode;
 186
 187         spin_unlock_irq(&led_dat->lock);
 188
 189         return 0;
 190 }
 191
 192 static void netxbig_led_set(struct led_classdev *led_cdev,
 193                             enum led_brightness value)
 194 {
 195         struct netxbig_led_data *led_dat =
 196                 container_of(led_cdev, struct netxbig_led_data, cdev);
 197         enum netxbig_led_mode mode;
 198         int mode_val, bright_val;
 199         int set_brightness = 1;
 200         unsigned long flags;
 201
 202         spin_lock_irqsave(&led_dat->lock, flags);
 203
 204         if (value == LED_OFF) {
 205                 mode = NETXBIG_LED_OFF;
 206                 set_brightness = 0;
 207         } else {
 208                 if (led_dat->sata)
 209                         mode = NETXBIG_LED_SATA;
 210                 else if (led_dat->mode == NETXBIG_LED_OFF)
 211                         mode = NETXBIG_LED_ON;
 212                 else /* Keep 'timer' mode. */
 213                         mode = led_dat->mode;
 214         }
 215         mode_val = led_dat->mode_val[mode];
 216
 217         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 218         led_dat->mode = mode;
 219         /*
 220          * Note that the brightness register is shared between all the
 221          * SATA LEDs. So, change the brightness setting for a single
 222          * SATA LED will affect all the others.
 223          */
 224         if (set_brightness) {
 225                 bright_val = DIV_ROUND_UP(value * led_dat->bright_max,
 226                                           LED_FULL);
 227                 gpio_ext_set_value(led_dat->gpio_ext,
 228                                    led_dat->bright_addr, bright_val);
 229         }
 230
 231         spin_unlock_irqrestore(&led_dat->lock, flags);
 232 }
 233
 234 static ssize_t netxbig_led_sata_store(struct device *dev,
 235                                       struct device_attribute *attr,
 236                                       const char *buff, size_t count)
 237 {
 238         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 239         struct netxbig_led_data *led_dat =
 240                 container_of(led_cdev, struct netxbig_led_data, cdev);
 241         unsigned long enable;
 242         enum netxbig_led_mode mode;
 243         int mode_val;
 244         int ret;
 245
 246         ret = kstrtoul(buff, 10, &enable);
 247         if (ret < 0)
 248                 return ret;
 249
 250         enable = !!enable;
 251
 252         spin_lock_irq(&led_dat->lock);
 253
 254         if (led_dat->sata == enable) {
 255                 ret = count;
 256                 goto exit_unlock;
 257         }
 258
 259         if (led_dat->mode != NETXBIG_LED_ON &&
 260             led_dat->mode != NETXBIG_LED_SATA)
 261                 mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
 262         else if (enable)
 263                 mode = NETXBIG_LED_SATA;
 264         else
 265                 mode = NETXBIG_LED_ON;
 266
 267         mode_val = led_dat->mode_val[mode];
 268         if (mode_val == NETXBIG_LED_INVALID_MODE) {
 269                 ret = -EINVAL;
 270                 goto exit_unlock;
 271         }
 272
 273         gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
 274         led_dat->mode = mode;
 275         led_dat->sata = enable;
 276
 277         ret = count;
 278
 279 exit_unlock:
 280         spin_unlock_irq(&led_dat->lock);
 281
 282         return ret;
 283 }
 284
 285 static ssize_t netxbig_led_sata_show(struct device *dev,
 286                                      struct device_attribute *attr, char *buf)
 287 {
 288         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 289         struct netxbig_led_data *led_dat =
 290                 container_of(led_cdev, struct netxbig_led_data, cdev);
 291
 292         return sprintf(buf, "%d\n", led_dat->sata);
 293 }
 294
 295 static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
 296
 297 static void delete_netxbig_led(struct netxbig_led_data *led_dat)
 298 {
 299         if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
 300                 device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
 301         led_classdev_unregister(&led_dat->cdev);
 302 }
 303
 304 static int
 305 create_netxbig_led(struct platform_device *pdev,
 306                    struct netxbig_led_data *led_dat,
 307                    const struct netxbig_led *template)
 308 {
 309         struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
 310         int ret;
 311
 312         spin_lock_init(&led_dat->lock);
 313         led_dat->gpio_ext = pdata->gpio_ext;
 314         led_dat->cdev.name = template->name;
 315         led_dat->cdev.default_trigger = template->default_trigger;
 316         led_dat->cdev.blink_set = netxbig_led_blink_set;
 317         led_dat->cdev.brightness_set = netxbig_led_set;
 318         /*
 319          * Because the GPIO extension bus don't allow to read registers
 320          * value, there is no way to probe the LED initial state.
 321          * So, the initial sysfs LED value for the "brightness" and "sata"
 322          * attributes are inconsistent.
 323          *
 324          * Note that the initial LED state can't be reconfigured.
 325          * The reason is that the LED behaviour must stay uniform during
 326          * the whole boot process (bootloader+linux).
 327          */
 328         led_dat->sata = 0;
 329         led_dat->cdev.brightness = LED_OFF;
 330         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 331         led_dat->mode_addr = template->mode_addr;
 332         led_dat->mode_val = template->mode_val;
 333         led_dat->bright_addr = template->bright_addr;
 334         led_dat->bright_max = (1 << pdata->gpio_ext->num_data) - 1;
 335         led_dat->timer = pdata->timer;
 336         led_dat->num_timer = pdata->num_timer;
 337
 338         ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 339         if (ret < 0)
 340                 return ret;
 341
 342         /*
 343          * If available, expose the SATA activity blink capability through
 344          * a "sata" sysfs attribute.
 345          */
 346         if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE) {
 347                 ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
 348                 if (ret)
 349                         led_classdev_unregister(&led_dat->cdev);
 350         }
 351
 352         return ret;
 353 }
 354
 355 static int netxbig_led_probe(struct platform_device *pdev)
 356 {
 357         struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
 358         struct netxbig_led_data *leds_data;
 359         int i;
 360         int ret;
 361
 362         if (!pdata)
 363                 return -EINVAL;
 364
 365         leds_data = devm_kzalloc(&pdev->dev,
 366                 sizeof(struct netxbig_led_data) * pdata->num_leds, GFP_KERNEL);
 367         if (!leds_data)
 368                 return -ENOMEM;
 369
 370         ret = gpio_ext_init(pdata->gpio_ext);
 371         if (ret < 0)
 372                 return ret;
 373
 374         for (i = 0; i < pdata->num_leds; i++) {
 375                 ret = create_netxbig_led(pdev, &leds_data[i], &pdata->leds[i]);
 376                 if (ret < 0)
 377                         goto err_free_leds;
 378         }
 379
 380         platform_set_drvdata(pdev, leds_data);
 381
 382         return 0;
 383
 384 err_free_leds:
 385         for (i = i - 1; i >= 0; i--)
 386                 delete_netxbig_led(&leds_data[i]);
 387
 388         gpio_ext_free(pdata->gpio_ext);
 389         return ret;
 390 }
 391
 392 static int netxbig_led_remove(struct platform_device *pdev)
 393 {
 394         struct netxbig_led_platform_data *pdata = pdev->dev.platform_data;
 395         struct netxbig_led_data *leds_data;
 396         int i;
 397
 398         leds_data = platform_get_drvdata(pdev);
 399
 400         for (i = 0; i < pdata->num_leds; i++)
 401                 delete_netxbig_led(&leds_data[i]);
 402
 403         gpio_ext_free(pdata->gpio_ext);
 404
 405         return 0;
 406 }
 407
 408 static struct platform_driver netxbig_led_driver = {
 409         .probe          = netxbig_led_probe,
 410         .remove         = netxbig_led_remove,
 411         .driver         = {
 412                 .name   = "leds-netxbig",
 413                 .owner  = THIS_MODULE,
 414         },
 415 };
 416
 417 module_platform_driver(netxbig_led_driver);
 418
 419 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 420 MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
 421 MODULE_LICENSE("GPL");
 422 MODULE_ALIAS("platform:leds-netxbig");