drivers/leds/leds-ns2.c

   1 /*
   2  * leds-ns2.c - Driver for the Network Space v2 (and parents) dual-GPIO LED
   3  *
   4  * Copyright (C) 2010 LaCie
   5  *
   6  * Author: Simon Guinot <sguinot@lacie.com>
   7  *
   8  * Based on leds-gpio.c by Raphael Assenat <raph@8d.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/slab.h>
  28 #include <linux/gpio.h>
  29 #include <linux/leds.h>
  30 #include <linux/module.h>
  31 #include <linux/platform_data/leds-kirkwood-ns2.h>
  32 #include <linux/of.h>
  33 #include <linux/of_gpio.h>
  34 #include "leds.h"
  35
  36 /*
  37  * The Network Space v2 dual-GPIO LED is wired to a CPLD. Three different LED
  38  * modes are available: off, on and SATA activity blinking. The LED modes are
  39  * controlled through two GPIOs (command and slow): each combination of values
  40  * for the command/slow GPIOs corresponds to a LED mode.
  41  */
  42
  43 struct ns2_led_data {
  44         struct led_classdev     cdev;
  45         unsigned                cmd;
  46         unsigned                slow;
  47         bool                    can_sleep;
  48         unsigned char           sata; /* True when SATA mode active. */
  49         rwlock_t                rw_lock; /* Lock GPIOs. */
  50         int                     num_modes;
  51         struct ns2_led_modval   *modval;
  52 };
  53
  54 static int ns2_led_get_mode(struct ns2_led_data *led_dat,
  55                             enum ns2_led_modes *mode)
  56 {
  57         int i;
  58         int ret = -EINVAL;
  59         int cmd_level;
  60         int slow_level;
  61
  62         cmd_level = gpio_get_value_cansleep(led_dat->cmd);
  63         slow_level = gpio_get_value_cansleep(led_dat->slow);
  64
  65         for (i = 0; i < led_dat->num_modes; i++) {
  66                 if (cmd_level == led_dat->modval[i].cmd_level &&
  67                     slow_level == led_dat->modval[i].slow_level) {
  68                         *mode = led_dat->modval[i].mode;
  69                         ret = 0;
  70                         break;
  71                 }
  72         }
  73
  74         return ret;
  75 }
  76
  77 static void ns2_led_set_mode(struct ns2_led_data *led_dat,
  78                              enum ns2_led_modes mode)
  79 {
  80         int i;
  81         bool found = false;
  82         unsigned long flags;
  83
  84         for (i = 0; i < led_dat->num_modes; i++)
  85                 if (mode == led_dat->modval[i].mode) {
  86                         found = true;
  87                         break;
  88                 }
  89
  90         if (!found)
  91                 return;
  92
  93         write_lock_irqsave(&led_dat->rw_lock, flags);
  94
  95         if (!led_dat->can_sleep) {
  96                 gpio_set_value(led_dat->cmd,
  97                                led_dat->modval[i].cmd_level);
  98                 gpio_set_value(led_dat->slow,
  99                                led_dat->modval[i].slow_level);
 100                 goto exit_unlock;
 101         }
 102
 103         gpio_set_value_cansleep(led_dat->cmd, led_dat->modval[i].cmd_level);
 104         gpio_set_value_cansleep(led_dat->slow, led_dat->modval[i].slow_level);
 105
 106 exit_unlock:
 107         write_unlock_irqrestore(&led_dat->rw_lock, flags);
 108 }
 109
 110 static void ns2_led_set(struct led_classdev *led_cdev,
 111                         enum led_brightness value)
 112 {
 113         struct ns2_led_data *led_dat =
 114                 container_of(led_cdev, struct ns2_led_data, cdev);
 115         enum ns2_led_modes mode;
 116
 117         if (value == LED_OFF)
 118                 mode = NS_V2_LED_OFF;
 119         else if (led_dat->sata)
 120                 mode = NS_V2_LED_SATA;
 121         else
 122                 mode = NS_V2_LED_ON;
 123
 124         ns2_led_set_mode(led_dat, mode);
 125 }
 126
 127 static int ns2_led_set_blocking(struct led_classdev *led_cdev,
 128                         enum led_brightness value)
 129 {
 130         ns2_led_set(led_cdev, value);
 131         return 0;
 132 }
 133
 134 static ssize_t ns2_led_sata_store(struct device *dev,
 135                                   struct device_attribute *attr,
 136                                   const char *buff, size_t count)
 137 {
 138         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 139         struct ns2_led_data *led_dat =
 140                 container_of(led_cdev, struct ns2_led_data, cdev);
 141         int ret;
 142         unsigned long enable;
 143
 144         ret = kstrtoul(buff, 10, &enable);
 145         if (ret < 0)
 146                 return ret;
 147
 148         enable = !!enable;
 149
 150         if (led_dat->sata == enable)
 151                 goto exit;
 152
 153         led_dat->sata = enable;
 154
 155         if (!led_get_brightness(led_cdev))
 156                 goto exit;
 157
 158         if (enable)
 159                 ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
 160         else
 161                 ns2_led_set_mode(led_dat, NS_V2_LED_ON);
 162
 163 exit:
 164         return count;
 165 }
 166
 167 static ssize_t ns2_led_sata_show(struct device *dev,
 168                                  struct device_attribute *attr, char *buf)
 169 {
 170         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 171         struct ns2_led_data *led_dat =
 172                 container_of(led_cdev, struct ns2_led_data, cdev);
 173
 174         return sprintf(buf, "%d\n", led_dat->sata);
 175 }
 176
 177 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
 178
 179 static struct attribute *ns2_led_attrs[] = {
 180         &dev_attr_sata.attr,
 181         NULL
 182 };
 183 ATTRIBUTE_GROUPS(ns2_led);
 184
 185 static int
 186 create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
 187                const struct ns2_led *template)
 188 {
 189         int ret;
 190         enum ns2_led_modes mode;
 191
 192         ret = devm_gpio_request_one(&pdev->dev, template->cmd,
 193                         gpio_get_value_cansleep(template->cmd) ?
 194                         GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
 195                         template->name);
 196         if (ret) {
 197                 dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
 198                         template->name);
 199                 return ret;
 200         }
 201
 202         ret = devm_gpio_request_one(&pdev->dev, template->slow,
 203                         gpio_get_value_cansleep(template->slow) ?
 204                         GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
 205                         template->name);
 206         if (ret) {
 207                 dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
 208                         template->name);
 209                 return ret;
 210         }
 211
 212         rwlock_init(&led_dat->rw_lock);
 213
 214         led_dat->cdev.name = template->name;
 215         led_dat->cdev.default_trigger = template->default_trigger;
 216         led_dat->cdev.blink_set = NULL;
 217         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 218         led_dat->cdev.groups = ns2_led_groups;
 219         led_dat->cmd = template->cmd;
 220         led_dat->slow = template->slow;
 221         led_dat->can_sleep = gpio_cansleep(led_dat->cmd) |
 222                                 gpio_cansleep(led_dat->slow);
 223         if (led_dat->can_sleep)
 224                 led_dat->cdev.brightness_set_blocking = ns2_led_set_blocking;
 225         else
 226                 led_dat->cdev.brightness_set = ns2_led_set;
 227         led_dat->modval = template->modval;
 228         led_dat->num_modes = template->num_modes;
 229
 230         ret = ns2_led_get_mode(led_dat, &mode);
 231         if (ret < 0)
 232                 return ret;
 233
 234         /* Set LED initial state. */
 235         led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
 236         led_dat->cdev.brightness =
 237                 (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
 238
 239         ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 240         if (ret < 0)
 241                 return ret;
 242
 243         return 0;
 244 }
 245
 246 static void delete_ns2_led(struct ns2_led_data *led_dat)
 247 {
 248         led_classdev_unregister(&led_dat->cdev);
 249 }
 250
 251 #ifdef CONFIG_OF_GPIO
 252 /*
 253  * Translate OpenFirmware node properties into platform_data.
 254  */
 255 static int
 256 ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
 257 {
 258         struct device_node *np = dev->of_node;
 259         struct device_node *child;
 260         struct ns2_led *led, *leds;
 261         int num_leds = 0;
 262
 263         num_leds = of_get_child_count(np);
 264         if (!num_leds)
 265                 return -ENODEV;
 266
 267         leds = devm_kzalloc(dev, num_leds * sizeof(struct ns2_led),
 268                             GFP_KERNEL);
 269         if (!leds)
 270                 return -ENOMEM;
 271
 272         led = leds;
 273         for_each_child_of_node(np, child) {
 274                 const char *string;
 275                 int ret, i, num_modes;
 276                 struct ns2_led_modval *modval;
 277
 278                 ret = of_get_named_gpio(child, "cmd-gpio", 0);
 279                 if (ret < 0)
 280                         return ret;
 281                 led->cmd = ret;
 282                 ret = of_get_named_gpio(child, "slow-gpio", 0);
 283                 if (ret < 0)
 284                         return ret;
 285                 led->slow = ret;
 286                 ret = of_property_read_string(child, "label", &string);
 287                 led->name = (ret == 0) ? string : child->name;
 288                 ret = of_property_read_string(child, "linux,default-trigger",
 289                                               &string);
 290                 if (ret == 0)
 291                         led->default_trigger = string;
 292
 293                 ret = of_property_count_u32_elems(child, "modes-map");
 294                 if (ret < 0 || ret % 3) {
 295                         dev_err(dev,
 296                                 "Missing or malformed modes-map property\n");
 297                         return -EINVAL;
 298                 }
 299
 300                 num_modes = ret / 3;
 301                 modval = devm_kzalloc(dev,
 302                                       num_modes * sizeof(struct ns2_led_modval),
 303                                       GFP_KERNEL);
 304                 if (!modval)
 305                         return -ENOMEM;
 306
 307                 for (i = 0; i < num_modes; i++) {
 308                         of_property_read_u32_index(child,
 309                                                 "modes-map", 3 * i,
 310                                                 (u32 *) &modval[i].mode);
 311                         of_property_read_u32_index(child,
 312                                                 "modes-map", 3 * i + 1,
 313                                                 (u32 *) &modval[i].cmd_level);
 314                         of_property_read_u32_index(child,
 315                                                 "modes-map", 3 * i + 2,
 316                                                 (u32 *) &modval[i].slow_level);
 317                 }
 318
 319                 led->num_modes = num_modes;
 320                 led->modval = modval;
 321
 322                 led++;
 323         }
 324
 325         pdata->leds = leds;
 326         pdata->num_leds = num_leds;
 327
 328         return 0;
 329 }
 330
 331 static const struct of_device_id of_ns2_leds_match[] = {
 332         { .compatible = "lacie,ns2-leds", },
 333         {},
 334 };
 335 MODULE_DEVICE_TABLE(of, of_ns2_leds_match);
 336 #endif /* CONFIG_OF_GPIO */
 337
 338 struct ns2_led_priv {
 339         int num_leds;
 340         struct ns2_led_data leds_data[];
 341 };
 342
 343 static inline int sizeof_ns2_led_priv(int num_leds)
 344 {
 345         return sizeof(struct ns2_led_priv) +
 346                       (sizeof(struct ns2_led_data) * num_leds);
 347 }
 348
 349 static int ns2_led_probe(struct platform_device *pdev)
 350 {
 351         struct ns2_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
 352         struct ns2_led_priv *priv;
 353         int i;
 354         int ret;
 355
 356 #ifdef CONFIG_OF_GPIO
 357         if (!pdata) {
 358                 pdata = devm_kzalloc(&pdev->dev,
 359                                      sizeof(struct ns2_led_platform_data),
 360                                      GFP_KERNEL);
 361                 if (!pdata)
 362                         return -ENOMEM;
 363
 364                 ret = ns2_leds_get_of_pdata(&pdev->dev, pdata);
 365                 if (ret)
 366                         return ret;
 367         }
 368 #else
 369         if (!pdata)
 370                 return -EINVAL;
 371 #endif /* CONFIG_OF_GPIO */
 372
 373         priv = devm_kzalloc(&pdev->dev,
 374                             sizeof_ns2_led_priv(pdata->num_leds), GFP_KERNEL);
 375         if (!priv)
 376                 return -ENOMEM;
 377         priv->num_leds = pdata->num_leds;
 378
 379         for (i = 0; i < priv->num_leds; i++) {
 380                 ret = create_ns2_led(pdev, &priv->leds_data[i],
 381                                      &pdata->leds[i]);
 382                 if (ret < 0) {
 383                         for (i = i - 1; i >= 0; i--)
 384                                 delete_ns2_led(&priv->leds_data[i]);
 385                         return ret;
 386                 }
 387         }
 388
 389         platform_set_drvdata(pdev, priv);
 390
 391         return 0;
 392 }
 393
 394 static int ns2_led_remove(struct platform_device *pdev)
 395 {
 396         int i;
 397         struct ns2_led_priv *priv;
 398
 399         priv = platform_get_drvdata(pdev);
 400
 401         for (i = 0; i < priv->num_leds; i++)
 402                 delete_ns2_led(&priv->leds_data[i]);
 403
 404         return 0;
 405 }
 406
 407 static struct platform_driver ns2_led_driver = {
 408         .probe          = ns2_led_probe,
 409         .remove         = ns2_led_remove,
 410         .driver         = {
 411                 .name           = "leds-ns2",
 412                 .of_match_table = of_match_ptr(of_ns2_leds_match),
 413         },
 414 };
 415
 416 module_platform_driver(ns2_led_driver);
 417
 418 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 419 MODULE_DESCRIPTION("Network Space v2 LED driver");
 420 MODULE_LICENSE("GPL");
 421 MODULE_ALIAS("platform:leds-ns2");