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         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 145         struct ns2_led_data *led_dat =
 146                 container_of(led_cdev, struct ns2_led_data, cdev);
 147         int ret;
 148         unsigned long enable;
 149         enum ns2_led_modes mode;
 150
 151         ret = strict_strtoul(buff, 10, &enable);
 152         if (ret < 0)
 153                 return ret;
 154
 155         enable = !!enable;
 156
 157         if (led_dat->sata == enable)
 158                 return count;
 159
 160         ret = ns2_led_get_mode(led_dat, &mode);
 161         if (ret < 0)
 162                 return ret;
 163
 164         if (enable && mode == NS_V2_LED_ON)
 165                 ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
 166         if (!enable && mode == NS_V2_LED_SATA)
 167                 ns2_led_set_mode(led_dat, NS_V2_LED_ON);
 168
 169         led_dat->sata = enable;
 170
 171         return count;
 172 }
 173
 174 static ssize_t ns2_led_sata_show(struct device *dev,
 175                                  struct device_attribute *attr, char *buf)
 176 {
 177         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 178         struct ns2_led_data *led_dat =
 179                 container_of(led_cdev, struct ns2_led_data, cdev);
 180
 181         return sprintf(buf, "%d\n", led_dat->sata);
 182 }
 183
 184 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
 185
 186 static int __devinit
 187 create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
 188                const struct ns2_led *template)
 189 {
 190         int ret;
 191         enum ns2_led_modes mode;
 192
 193         ret = gpio_request(template->cmd, template->name);
 194         if (ret == 0) {
 195                 ret = gpio_direction_output(template->cmd,
 196                                             gpio_get_value(template->cmd));
 197                 if (ret)
 198                         gpio_free(template->cmd);
 199         }
 200         if (ret) {
 201                 dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
 202                         template->name);
 203         }
 204
 205         ret = gpio_request(template->slow, template->name);
 206         if (ret == 0) {
 207                 ret = gpio_direction_output(template->slow,
 208                                             gpio_get_value(template->slow));
 209                 if (ret)
 210                         gpio_free(template->slow);
 211         }
 212         if (ret) {
 213                 dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
 214                         template->name);
 215                 goto err_free_cmd;
 216         }
 217
 218         rwlock_init(&led_dat->rw_lock);
 219
 220         led_dat->cdev.name = template->name;
 221         led_dat->cdev.default_trigger = template->default_trigger;
 222         led_dat->cdev.blink_set = NULL;
 223         led_dat->cdev.brightness_set = ns2_led_set;
 224         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 225         led_dat->cmd = template->cmd;
 226         led_dat->slow = template->slow;
 227
 228         ret = ns2_led_get_mode(led_dat, &mode);
 229         if (ret < 0)
 230                 goto err_free_slow;
 231
 232         /* Set LED initial state. */
 233         led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
 234         led_dat->cdev.brightness =
 235                 (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
 236
 237         ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 238         if (ret < 0)
 239                 goto err_free_slow;
 240
 241         ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
 242         if (ret < 0)
 243                 goto err_free_cdev;
 244
 245         return 0;
 246
 247 err_free_cdev:
 248         led_classdev_unregister(&led_dat->cdev);
 249 err_free_slow:
 250         gpio_free(led_dat->slow);
 251 err_free_cmd:
 252         gpio_free(led_dat->cmd);
 253
 254         return ret;
 255 }
 256
 257 static void __devexit delete_ns2_led(struct ns2_led_data *led_dat)
 258 {
 259         device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
 260         led_classdev_unregister(&led_dat->cdev);
 261         gpio_free(led_dat->cmd);
 262         gpio_free(led_dat->slow);
 263 }
 264
 265 static int __devinit ns2_led_probe(struct platform_device *pdev)
 266 {
 267         struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
 268         struct ns2_led_data *leds_data;
 269         int i;
 270         int ret;
 271
 272         if (!pdata)
 273                 return -EINVAL;
 274
 275         leds_data = kzalloc(sizeof(struct ns2_led_data) *
 276                             pdata->num_leds, GFP_KERNEL);
 277         if (!leds_data)
 278                 return -ENOMEM;
 279
 280         for (i = 0; i < pdata->num_leds; i++) {
 281                 ret = create_ns2_led(pdev, &leds_data[i], &pdata->leds[i]);
 282                 if (ret < 0)
 283                         goto err;
 284
 285         }
 286
 287         platform_set_drvdata(pdev, leds_data);
 288
 289         return 0;
 290
 291 err:
 292         for (i = i - 1; i >= 0; i--)
 293                 delete_ns2_led(&leds_data[i]);
 294
 295         kfree(leds_data);
 296
 297         return ret;
 298 }
 299
 300 static int __devexit ns2_led_remove(struct platform_device *pdev)
 301 {
 302         int i;
 303         struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
 304         struct ns2_led_data *leds_data;
 305
 306         leds_data = platform_get_drvdata(pdev);
 307
 308         for (i = 0; i < pdata->num_leds; i++)
 309                 delete_ns2_led(&leds_data[i]);
 310
 311         kfree(leds_data);
 312         platform_set_drvdata(pdev, NULL);
 313
 314         return 0;
 315 }
 316
 317 static struct platform_driver ns2_led_driver = {
 318         .probe          = ns2_led_probe,
 319         .remove         = __devexit_p(ns2_led_remove),
 320         .driver         = {
 321                 .name   = "leds-ns2",
 322                 .owner  = THIS_MODULE,
 323         },
 324 };
 325 MODULE_ALIAS("platform:leds-ns2");
 326
 327 static int __init ns2_led_init(void)
 328 {
 329         return platform_driver_register(&ns2_led_driver);
 330 }
 331
 332 static void __exit ns2_led_exit(void)
 333 {
 334         platform_driver_unregister(&ns2_led_driver);
 335 }
 336
 337 module_init(ns2_led_init);
 338 module_exit(ns2_led_exit);
 339
 340 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 341 MODULE_DESCRIPTION("Network Space v2 LED driver");
 342 MODULE_LICENSE("GPL");