release/src-rt-6.x.4708/linux/linux-2.6.36/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 <mach/leds-ns2.h>
  32
  33 /*
  34  * The Network Space v2 dual-GPIO LED is wired to a CPLD and can blink in
  35  * relation with the SATA activity. This capability is exposed through the
  36  * "sata" sysfs attribute.
  37  *
  38  * The following array detail the different LED registers and the combination
  39  * of their possible values:
  40  *
  41  *  cmd_led   |  slow_led  | /SATA active | LED state
  42  *            |            |              |
  43  *     1      |     0      |      x       |  off
  44  *     -      |     1      |      x       |  on
  45  *     0      |     0      |      1       |  on
  46  *     0      |     0      |      0       |  blink (rate 300ms)
  47  */
  48
  49 enum ns2_led_modes {
  50         NS_V2_LED_OFF,
  51         NS_V2_LED_ON,
  52         NS_V2_LED_SATA,
  53 };
  54
  55 struct ns2_led_mode_value {
  56         enum ns2_led_modes      mode;
  57         int                     cmd_level;
  58         int                     slow_level;
  59 };
  60
  61 static struct ns2_led_mode_value ns2_led_modval[] = {
  62         { NS_V2_LED_OFF , 1, 0 },
  63         { NS_V2_LED_ON  , 0, 1 },
  64         { NS_V2_LED_ON  , 1, 1 },
  65         { NS_V2_LED_SATA, 0, 0 },
  66 };
  67
  68 struct ns2_led_data {
  69         struct led_classdev     cdev;
  70         unsigned                cmd;
  71         unsigned                slow;
  72         unsigned char           sata; /* True when SATA mode active. */
  73         rwlock_t                rw_lock; /* Lock GPIOs. */
  74 };
  75
  76 static int ns2_led_get_mode(struct ns2_led_data *led_dat,
  77                             enum ns2_led_modes *mode)
  78 {
  79         int i;
  80         int ret = -EINVAL;
  81         int cmd_level;
  82         int slow_level;
  83
  84         read_lock_irq(&led_dat->rw_lock);
  85
  86         cmd_level = gpio_get_value(led_dat->cmd);
  87         slow_level = gpio_get_value(led_dat->slow);
  88
  89         for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
  90                 if (cmd_level == ns2_led_modval[i].cmd_level &&
  91                     slow_level == ns2_led_modval[i].slow_level) {
  92                         *mode = ns2_led_modval[i].mode;
  93                         ret = 0;
  94                         break;
  95                 }
  96         }
  97
  98         read_unlock_irq(&led_dat->rw_lock);
  99
 100         return ret;
 101 }
 102
 103 static void ns2_led_set_mode(struct ns2_led_data *led_dat,
 104                              enum ns2_led_modes mode)
 105 {
 106         int i;
 107         unsigned long flags;
 108
 109         write_lock_irqsave(&led_dat->rw_lock, flags);
 110
 111         for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
 112                 if (mode == ns2_led_modval[i].mode) {
 113                         gpio_set_value(led_dat->cmd,
 114                                        ns2_led_modval[i].cmd_level);
 115                         gpio_set_value(led_dat->slow,
 116                                        ns2_led_modval[i].slow_level);
 117                 }
 118         }
 119
 120         write_unlock_irqrestore(&led_dat->rw_lock, flags);
 121 }
 122
 123 static void ns2_led_set(struct led_classdev *led_cdev,
 124                         enum led_brightness value)
 125 {
 126         struct ns2_led_data *led_dat =
 127                 container_of(led_cdev, struct ns2_led_data, cdev);
 128         enum ns2_led_modes mode;
 129
 130         if (value == LED_OFF)
 131                 mode = NS_V2_LED_OFF;
 132         else if (led_dat->sata)
 133                 mode = NS_V2_LED_SATA;
 134         else
 135                 mode = NS_V2_LED_ON;
 136
 137         ns2_led_set_mode(led_dat, mode);
 138 }
 139
 140 static ssize_t ns2_led_sata_store(struct device *dev,
 141                                   struct device_attribute *attr,
 142                                   const char *buff, size_t count)
 143 {
 144         int ret;
 145         unsigned long enable;
 146         enum ns2_led_modes mode;
 147         struct ns2_led_data *led_dat = dev_get_drvdata(dev);
 148
 149         ret = strict_strtoul(buff, 10, &enable);
 150         if (ret < 0)
 151                 return ret;
 152
 153         enable = !!enable;
 154
 155         if (led_dat->sata == enable)
 156                 return count;
 157
 158         ret = ns2_led_get_mode(led_dat, &mode);
 159         if (ret < 0)
 160                 return ret;
 161
 162         if (enable && mode == NS_V2_LED_ON)
 163                 ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
 164         if (!enable && mode == NS_V2_LED_SATA)
 165                 ns2_led_set_mode(led_dat, NS_V2_LED_ON);
 166
 167         led_dat->sata = enable;
 168
 169         return count;
 170 }
 171
 172 static ssize_t ns2_led_sata_show(struct device *dev,
 173                                  struct device_attribute *attr, char *buf)
 174 {
 175         struct ns2_led_data *led_dat = dev_get_drvdata(dev);
 176
 177         return sprintf(buf, "%d\n", led_dat->sata);
 178 }
 179
 180 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
 181
 182 static int __devinit
 183 create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
 184                const struct ns2_led *template)
 185 {
 186         int ret;
 187         enum ns2_led_modes mode;
 188
 189         ret = gpio_request(template->cmd, template->name);
 190         if (ret == 0) {
 191                 ret = gpio_direction_output(template->cmd,
 192                                             gpio_get_value(template->cmd));
 193                 if (ret)
 194                         gpio_free(template->cmd);
 195         }
 196         if (ret) {
 197                 dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
 198                         template->name);
 199         }
 200
 201         ret = gpio_request(template->slow, template->name);
 202         if (ret == 0) {
 203                 ret = gpio_direction_output(template->slow,
 204                                             gpio_get_value(template->slow));
 205                 if (ret)
 206                         gpio_free(template->slow);
 207         }
 208         if (ret) {
 209                 dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
 210                         template->name);
 211                 goto err_free_cmd;
 212         }
 213
 214         rwlock_init(&led_dat->rw_lock);
 215
 216         led_dat->cdev.name = template->name;
 217         led_dat->cdev.default_trigger = template->default_trigger;
 218         led_dat->cdev.blink_set = NULL;
 219         led_dat->cdev.brightness_set = ns2_led_set;
 220         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 221         led_dat->cmd = template->cmd;
 222         led_dat->slow = template->slow;
 223
 224         ret = ns2_led_get_mode(led_dat, &mode);
 225         if (ret < 0)
 226                 goto err_free_slow;
 227
 228         /* Set LED initial state. */
 229         led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
 230         led_dat->cdev.brightness =
 231                 (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
 232
 233         ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 234         if (ret < 0)
 235                 goto err_free_slow;
 236
 237         dev_set_drvdata(led_dat->cdev.dev, led_dat);
 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 err_free_slow:
 247         gpio_free(led_dat->slow);
 248 err_free_cmd:
 249         gpio_free(led_dat->cmd);
 250
 251         return ret;
 252 }
 253
 254 static void __devexit delete_ns2_led(struct ns2_led_data *led_dat)
 255 {
 256         device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
 257         led_classdev_unregister(&led_dat->cdev);
 258         gpio_free(led_dat->cmd);
 259         gpio_free(led_dat->slow);
 260 }
 261
 262 static int __devinit ns2_led_probe(struct platform_device *pdev)
 263 {
 264         struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
 265         struct ns2_led_data *leds_data;
 266         int i;
 267         int ret;
 268
 269         if (!pdata)
 270                 return -EINVAL;
 271
 272         leds_data = kzalloc(sizeof(struct ns2_led_data) *
 273                             pdata->num_leds, GFP_KERNEL);
 274         if (!leds_data)
 275                 return -ENOMEM;
 276
 277         for (i = 0; i < pdata->num_leds; i++) {
 278                 ret = create_ns2_led(pdev, &leds_data[i], &pdata->leds[i]);
 279                 if (ret < 0)
 280                         goto err;
 281
 282         }
 283
 284         platform_set_drvdata(pdev, leds_data);
 285
 286         return 0;
 287
 288 err:
 289         for (i = i - 1; i >= 0; i--)
 290                 delete_ns2_led(&leds_data[i]);
 291
 292         kfree(leds_data);
 293
 294         return ret;
 295 }
 296
 297 static int __devexit ns2_led_remove(struct platform_device *pdev)
 298 {
 299         int i;
 300         struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
 301         struct ns2_led_data *leds_data;
 302
 303         leds_data = platform_get_drvdata(pdev);
 304
 305         for (i = 0; i < pdata->num_leds; i++)
 306                 delete_ns2_led(&leds_data[i]);
 307
 308         kfree(leds_data);
 309         platform_set_drvdata(pdev, NULL);
 310
 311         return 0;
 312 }
 313
 314 static struct platform_driver ns2_led_driver = {
 315         .probe          = ns2_led_probe,
 316         .remove         = __devexit_p(ns2_led_remove),
 317         .driver         = {
 318                 .name   = "leds-ns2",
 319                 .owner  = THIS_MODULE,
 320         },
 321 };
 322 MODULE_ALIAS("platform:leds-ns2");
 323
 324 static int __init ns2_led_init(void)
 325 {
 326         return platform_driver_register(&ns2_led_driver);
 327 }
 328
 329 static void __exit ns2_led_exit(void)
 330 {
 331         platform_driver_unregister(&ns2_led_driver);
 332 }
 333
 334 module_init(ns2_led_init);
 335 module_exit(ns2_led_exit);
 336
 337 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 338 MODULE_DESCRIPTION("Network Space v2 LED driver");
 339 MODULE_LICENSE("GPL");