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/init.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/slab.h>
  29 #include <linux/gpio.h>
  30 #include <linux/leds.h>
  31 #include <linux/module.h>
  32 #include <linux/platform_data/leds-kirkwood-ns2.h>
  33 #include <linux/of_gpio.h>
  34
  35 /*
  36  * The Network Space v2 dual-GPIO LED is wired to a CPLD and can blink in
  37  * relation with the SATA activity. This capability is exposed through the
  38  * "sata" sysfs attribute.
  39  *
  40  * The following array detail the different LED registers and the combination
  41  * of their possible values:
  42  *
  43  *  cmd_led   |  slow_led  | /SATA active | LED state
  44  *            |            |              |
  45  *     1      |     0      |      x       |  off
  46  *     -      |     1      |      x       |  on
  47  *     0      |     0      |      1       |  on
  48  *     0      |     0      |      0       |  blink (rate 300ms)
  49  */
  50
  51 enum ns2_led_modes {
  52         NS_V2_LED_OFF,
  53         NS_V2_LED_ON,
  54         NS_V2_LED_SATA,
  55 };
  56
  57 struct ns2_led_mode_value {
  58         enum ns2_led_modes      mode;
  59         int                     cmd_level;
  60         int                     slow_level;
  61 };
  62
  63 static struct ns2_led_mode_value ns2_led_modval[] = {
  64         { NS_V2_LED_OFF , 1, 0 },
  65         { NS_V2_LED_ON  , 0, 1 },
  66         { NS_V2_LED_ON  , 1, 1 },
  67         { NS_V2_LED_SATA, 0, 0 },
  68 };
  69
  70 struct ns2_led_data {
  71         struct led_classdev     cdev;
  72         unsigned                cmd;
  73         unsigned                slow;
  74         unsigned char           sata; /* True when SATA mode active. */
  75         rwlock_t                rw_lock; /* Lock GPIOs. */
  76 };
  77
  78 static int ns2_led_get_mode(struct ns2_led_data *led_dat,
  79                             enum ns2_led_modes *mode)
  80 {
  81         int i;
  82         int ret = -EINVAL;
  83         int cmd_level;
  84         int slow_level;
  85
  86         read_lock_irq(&led_dat->rw_lock);
  87
  88         cmd_level = gpio_get_value(led_dat->cmd);
  89         slow_level = gpio_get_value(led_dat->slow);
  90
  91         for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
  92                 if (cmd_level == ns2_led_modval[i].cmd_level &&
  93                     slow_level == ns2_led_modval[i].slow_level) {
  94                         *mode = ns2_led_modval[i].mode;
  95                         ret = 0;
  96                         break;
  97                 }
  98         }
  99
 100         read_unlock_irq(&led_dat->rw_lock);
 101
 102         return ret;
 103 }
 104
 105 static void ns2_led_set_mode(struct ns2_led_data *led_dat,
 106                              enum ns2_led_modes mode)
 107 {
 108         int i;
 109         unsigned long flags;
 110
 111         write_lock_irqsave(&led_dat->rw_lock, flags);
 112
 113         for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
 114                 if (mode == ns2_led_modval[i].mode) {
 115                         gpio_set_value(led_dat->cmd,
 116                                        ns2_led_modval[i].cmd_level);
 117                         gpio_set_value(led_dat->slow,
 118                                        ns2_led_modval[i].slow_level);
 119                 }
 120         }
 121
 122         write_unlock_irqrestore(&led_dat->rw_lock, flags);
 123 }
 124
 125 static void ns2_led_set(struct led_classdev *led_cdev,
 126                         enum led_brightness value)
 127 {
 128         struct ns2_led_data *led_dat =
 129                 container_of(led_cdev, struct ns2_led_data, cdev);
 130         enum ns2_led_modes mode;
 131
 132         if (value == LED_OFF)
 133                 mode = NS_V2_LED_OFF;
 134         else if (led_dat->sata)
 135                 mode = NS_V2_LED_SATA;
 136         else
 137                 mode = NS_V2_LED_ON;
 138
 139         ns2_led_set_mode(led_dat, mode);
 140 }
 141
 142 static ssize_t ns2_led_sata_store(struct device *dev,
 143                                   struct device_attribute *attr,
 144                                   const char *buff, size_t count)
 145 {
 146         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 147         struct ns2_led_data *led_dat =
 148                 container_of(led_cdev, struct ns2_led_data, cdev);
 149         int ret;
 150         unsigned long enable;
 151         enum ns2_led_modes mode;
 152
 153         ret = kstrtoul(buff, 10, &enable);
 154         if (ret < 0)
 155                 return ret;
 156
 157         enable = !!enable;
 158
 159         if (led_dat->sata == enable)
 160                 return count;
 161
 162         ret = ns2_led_get_mode(led_dat, &mode);
 163         if (ret < 0)
 164                 return ret;
 165
 166         if (enable && mode == NS_V2_LED_ON)
 167                 ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
 168         if (!enable && mode == NS_V2_LED_SATA)
 169                 ns2_led_set_mode(led_dat, NS_V2_LED_ON);
 170
 171         led_dat->sata = enable;
 172
 173         return count;
 174 }
 175
 176 static ssize_t ns2_led_sata_show(struct device *dev,
 177                                  struct device_attribute *attr, char *buf)
 178 {
 179         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 180         struct ns2_led_data *led_dat =
 181                 container_of(led_cdev, struct ns2_led_data, cdev);
 182
 183         return sprintf(buf, "%d\n", led_dat->sata);
 184 }
 185
 186 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
 187
 188 static int
 189 create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
 190                const struct ns2_led *template)
 191 {
 192         int ret;
 193         enum ns2_led_modes mode;
 194
 195         ret = devm_gpio_request_one(&pdev->dev, template->cmd,
 196                         gpio_get_value(template->cmd) ?
 197                         GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
 198                         template->name);
 199         if (ret) {
 200                 dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
 201                         template->name);
 202                 return ret;
 203         }
 204
 205         ret = devm_gpio_request_one(&pdev->dev, template->slow,
 206                         gpio_get_value(template->slow) ?
 207                         GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
 208                         template->name);
 209         if (ret) {
 210                 dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
 211                         template->name);
 212                 return ret;
 213         }
 214
 215         rwlock_init(&led_dat->rw_lock);
 216
 217         led_dat->cdev.name = template->name;
 218         led_dat->cdev.default_trigger = template->default_trigger;
 219         led_dat->cdev.blink_set = NULL;
 220         led_dat->cdev.brightness_set = ns2_led_set;
 221         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 222         led_dat->cmd = template->cmd;
 223         led_dat->slow = template->slow;
 224
 225         ret = ns2_led_get_mode(led_dat, &mode);
 226         if (ret < 0)
 227                 return ret;
 228
 229         /* Set LED initial state. */
 230         led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
 231         led_dat->cdev.brightness =
 232                 (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
 233
 234         ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 235         if (ret < 0)
 236                 return ret;
 237
 238         ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
 239         if (ret < 0)
 240                 goto err_free_cdev;
 241
 242         return 0;
 243
 244 err_free_cdev:
 245         led_classdev_unregister(&led_dat->cdev);
 246         return ret;
 247 }
 248
 249 static void delete_ns2_led(struct ns2_led_data *led_dat)
 250 {
 251         device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
 252         led_classdev_unregister(&led_dat->cdev);
 253 }
 254
 255 #ifdef CONFIG_OF_GPIO
 256 /*
 257  * Translate OpenFirmware node properties into platform_data.
 258  */
 259 static int
 260 ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
 261 {
 262         struct device_node *np = dev->of_node;
 263         struct device_node *child;
 264         struct ns2_led *leds;
 265         int num_leds = 0;
 266         int i = 0;
 267
 268         num_leds = of_get_child_count(np);
 269         if (!num_leds)
 270                 return -ENODEV;
 271
 272         leds = devm_kzalloc(dev, num_leds * sizeof(struct ns2_led),
 273                             GFP_KERNEL);
 274         if (!leds)
 275                 return -ENOMEM;
 276
 277         for_each_child_of_node(np, child) {
 278                 const char *string;
 279                 int ret;
 280
 281                 ret = of_get_named_gpio(child, "cmd-gpio", 0);
 282                 if (ret < 0)
 283                         return ret;
 284                 leds[i].cmd = ret;
 285                 ret = of_get_named_gpio(child, "slow-gpio", 0);
 286                 if (ret < 0)
 287                         return ret;
 288                 leds[i].slow = ret;
 289                 ret = of_property_read_string(child, "label", &string);
 290                 leds[i].name = (ret == 0) ? string : child->name;
 291                 ret = of_property_read_string(child, "linux,default-trigger",
 292                                               &string);
 293                 if (ret == 0)
 294                         leds[i].default_trigger = string;
 295
 296                 i++;
 297         }
 298
 299         pdata->leds = leds;
 300         pdata->num_leds = num_leds;
 301
 302         return 0;
 303 }
 304
 305 static const struct of_device_id of_ns2_leds_match[] = {
 306         { .compatible = "lacie,ns2-leds", },
 307         {},
 308 };
 309 #endif /* CONFIG_OF_GPIO */
 310
 311 struct ns2_led_priv {
 312         int num_leds;
 313         struct ns2_led_data leds_data[];
 314 };
 315
 316 static inline int sizeof_ns2_led_priv(int num_leds)
 317 {
 318         return sizeof(struct ns2_led_priv) +
 319                       (sizeof(struct ns2_led_data) * num_leds);
 320 }
 321
 322 static int ns2_led_probe(struct platform_device *pdev)
 323 {
 324         struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
 325         struct ns2_led_priv *priv;
 326         int i;
 327         int ret;
 328
 329 #ifdef CONFIG_OF_GPIO
 330         if (!pdata) {
 331                 pdata = devm_kzalloc(&pdev->dev,
 332                                      sizeof(struct ns2_led_platform_data),
 333                                      GFP_KERNEL);
 334                 if (!pdata)
 335                         return -ENOMEM;
 336
 337                 ret = ns2_leds_get_of_pdata(&pdev->dev, pdata);
 338                 if (ret)
 339                         return ret;
 340         }
 341 #else
 342         if (!pdata)
 343                 return -EINVAL;
 344 #endif /* CONFIG_OF_GPIO */
 345
 346         priv = devm_kzalloc(&pdev->dev,
 347                             sizeof_ns2_led_priv(pdata->num_leds), GFP_KERNEL);
 348         if (!priv)
 349                 return -ENOMEM;
 350         priv->num_leds = pdata->num_leds;
 351
 352         for (i = 0; i < priv->num_leds; i++) {
 353                 ret = create_ns2_led(pdev, &priv->leds_data[i],
 354                                      &pdata->leds[i]);
 355                 if (ret < 0) {
 356                         for (i = i - 1; i >= 0; i--)
 357                                 delete_ns2_led(&priv->leds_data[i]);
 358                         return ret;
 359                 }
 360         }
 361
 362         platform_set_drvdata(pdev, priv);
 363
 364         return 0;
 365 }
 366
 367 static int ns2_led_remove(struct platform_device *pdev)
 368 {
 369         int i;
 370         struct ns2_led_priv *priv;
 371
 372         priv = platform_get_drvdata(pdev);
 373
 374         for (i = 0; i < priv->num_leds; i++)
 375                 delete_ns2_led(&priv->leds_data[i]);
 376
 377         platform_set_drvdata(pdev, NULL);
 378
 379         return 0;
 380 }
 381
 382 static struct platform_driver ns2_led_driver = {
 383         .probe          = ns2_led_probe,
 384         .remove         = ns2_led_remove,
 385         .driver         = {
 386                 .name           = "leds-ns2",
 387                 .owner          = THIS_MODULE,
 388                 .of_match_table = of_match_ptr(of_ns2_leds_match),
 389         },
 390 };
 391
 392 module_platform_driver(ns2_led_driver);
 393
 394 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 395 MODULE_DESCRIPTION("Network Space v2 LED driver");
 396 MODULE_LICENSE("GPL");
 397 MODULE_ALIAS("platform:leds-ns2");