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 <mach/leds-ns2.h>
  33
  34 /*
  35  * The Network Space v2 dual-GPIO LED is wired to a CPLD and can blink in
  36  * relation with the SATA activity. This capability is exposed through the
  37  * "sata" sysfs attribute.
  38  *
  39  * The following array detail the different LED registers and the combination
  40  * of their possible values:
  41  *
  42  *  cmd_led   |  slow_led  | /SATA active | LED state
  43  *            |            |              |
  44  *     1      |     0      |      x       |  off
  45  *     -      |     1      |      x       |  on
  46  *     0      |     0      |      1       |  on
  47  *     0      |     0      |      0       |  blink (rate 300ms)
  48  */
  49
  50 enum ns2_led_modes {
  51         NS_V2_LED_OFF,
  52         NS_V2_LED_ON,
  53         NS_V2_LED_SATA,
  54 };
  55
  56 struct ns2_led_mode_value {
  57         enum ns2_led_modes      mode;
  58         int                     cmd_level;
  59         int                     slow_level;
  60 };
  61
  62 static struct ns2_led_mode_value ns2_led_modval[] = {
  63         { NS_V2_LED_OFF , 1, 0 },
  64         { NS_V2_LED_ON  , 0, 1 },
  65         { NS_V2_LED_ON  , 1, 1 },
  66         { NS_V2_LED_SATA, 0, 0 },
  67 };
  68
  69 struct ns2_led_data {
  70         struct led_classdev     cdev;
  71         unsigned                cmd;
  72         unsigned                slow;
  73         unsigned char           sata; /* True when SATA mode active. */
  74         rwlock_t                rw_lock; /* Lock GPIOs. */
  75 };
  76
  77 static int ns2_led_get_mode(struct ns2_led_data *led_dat,
  78                             enum ns2_led_modes *mode)
  79 {
  80         int i;
  81         int ret = -EINVAL;
  82         int cmd_level;
  83         int slow_level;
  84
  85         read_lock_irq(&led_dat->rw_lock);
  86
  87         cmd_level = gpio_get_value(led_dat->cmd);
  88         slow_level = gpio_get_value(led_dat->slow);
  89
  90         for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
  91                 if (cmd_level == ns2_led_modval[i].cmd_level &&
  92                     slow_level == ns2_led_modval[i].slow_level) {
  93                         *mode = ns2_led_modval[i].mode;
  94                         ret = 0;
  95                         break;
  96                 }
  97         }
  98
  99         read_unlock_irq(&led_dat->rw_lock);
 100
 101         return ret;
 102 }
 103
 104 static void ns2_led_set_mode(struct ns2_led_data *led_dat,
 105                              enum ns2_led_modes mode)
 106 {
 107         int i;
 108         unsigned long flags;
 109
 110         write_lock_irqsave(&led_dat->rw_lock, flags);
 111
 112         for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
 113                 if (mode == ns2_led_modval[i].mode) {
 114                         gpio_set_value(led_dat->cmd,
 115                                        ns2_led_modval[i].cmd_level);
 116                         gpio_set_value(led_dat->slow,
 117                                        ns2_led_modval[i].slow_level);
 118                 }
 119         }
 120
 121         write_unlock_irqrestore(&led_dat->rw_lock, flags);
 122 }
 123
 124 static void ns2_led_set(struct led_classdev *led_cdev,
 125                         enum led_brightness value)
 126 {
 127         struct ns2_led_data *led_dat =
 128                 container_of(led_cdev, struct ns2_led_data, cdev);
 129         enum ns2_led_modes mode;
 130
 131         if (value == LED_OFF)
 132                 mode = NS_V2_LED_OFF;
 133         else if (led_dat->sata)
 134                 mode = NS_V2_LED_SATA;
 135         else
 136                 mode = NS_V2_LED_ON;
 137
 138         ns2_led_set_mode(led_dat, mode);
 139 }
 140
 141 static ssize_t ns2_led_sata_store(struct device *dev,
 142                                   struct device_attribute *attr,
 143                                   const char *buff, size_t count)
 144 {
 145         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 146         struct ns2_led_data *led_dat =
 147                 container_of(led_cdev, struct ns2_led_data, cdev);
 148         int ret;
 149         unsigned long enable;
 150         enum ns2_led_modes mode;
 151
 152         ret = strict_strtoul(buff, 10, &enable);
 153         if (ret < 0)
 154                 return ret;
 155
 156         enable = !!enable;
 157
 158         if (led_dat->sata == enable)
 159                 return count;
 160
 161         ret = ns2_led_get_mode(led_dat, &mode);
 162         if (ret < 0)
 163                 return ret;
 164
 165         if (enable && mode == NS_V2_LED_ON)
 166                 ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
 167         if (!enable && mode == NS_V2_LED_SATA)
 168                 ns2_led_set_mode(led_dat, NS_V2_LED_ON);
 169
 170         led_dat->sata = enable;
 171
 172         return count;
 173 }
 174
 175 static ssize_t ns2_led_sata_show(struct device *dev,
 176                                  struct device_attribute *attr, char *buf)
 177 {
 178         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 179         struct ns2_led_data *led_dat =
 180                 container_of(led_cdev, struct ns2_led_data, cdev);
 181
 182         return sprintf(buf, "%d\n", led_dat->sata);
 183 }
 184
 185 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
 186
 187 static int __devinit
 188 create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
 189                const struct ns2_led *template)
 190 {
 191         int ret;
 192         enum ns2_led_modes mode;
 193
 194         ret = gpio_request(template->cmd, template->name);
 195         if (ret == 0) {
 196                 ret = gpio_direction_output(template->cmd,
 197                                             gpio_get_value(template->cmd));
 198                 if (ret)
 199                         gpio_free(template->cmd);
 200         }
 201         if (ret) {
 202                 dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
 203                         template->name);
 204         }
 205
 206         ret = gpio_request(template->slow, template->name);
 207         if (ret == 0) {
 208                 ret = gpio_direction_output(template->slow,
 209                                             gpio_get_value(template->slow));
 210                 if (ret)
 211                         gpio_free(template->slow);
 212         }
 213         if (ret) {
 214                 dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
 215                         template->name);
 216                 goto err_free_cmd;
 217         }
 218
 219         rwlock_init(&led_dat->rw_lock);
 220
 221         led_dat->cdev.name = template->name;
 222         led_dat->cdev.default_trigger = template->default_trigger;
 223         led_dat->cdev.blink_set = NULL;
 224         led_dat->cdev.brightness_set = ns2_led_set;
 225         led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 226         led_dat->cmd = template->cmd;
 227         led_dat->slow = template->slow;
 228
 229         ret = ns2_led_get_mode(led_dat, &mode);
 230         if (ret < 0)
 231                 goto err_free_slow;
 232
 233         /* Set LED initial state. */
 234         led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
 235         led_dat->cdev.brightness =
 236                 (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
 237
 238         ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 239         if (ret < 0)
 240                 goto err_free_slow;
 241
 242         ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
 243         if (ret < 0)
 244                 goto err_free_cdev;
 245
 246         return 0;
 247
 248 err_free_cdev:
 249         led_classdev_unregister(&led_dat->cdev);
 250 err_free_slow:
 251         gpio_free(led_dat->slow);
 252 err_free_cmd:
 253         gpio_free(led_dat->cmd);
 254
 255         return ret;
 256 }
 257
 258 static void __devexit delete_ns2_led(struct ns2_led_data *led_dat)
 259 {
 260         device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
 261         led_classdev_unregister(&led_dat->cdev);
 262         gpio_free(led_dat->cmd);
 263         gpio_free(led_dat->slow);
 264 }
 265
 266 static int __devinit ns2_led_probe(struct platform_device *pdev)
 267 {
 268         struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
 269         struct ns2_led_data *leds_data;
 270         int i;
 271         int ret;
 272
 273         if (!pdata)
 274                 return -EINVAL;
 275
 276         leds_data = kzalloc(sizeof(struct ns2_led_data) *
 277                             pdata->num_leds, GFP_KERNEL);
 278         if (!leds_data)
 279                 return -ENOMEM;
 280
 281         for (i = 0; i < pdata->num_leds; i++) {
 282                 ret = create_ns2_led(pdev, &leds_data[i], &pdata->leds[i]);
 283                 if (ret < 0)
 284                         goto err;
 285
 286         }
 287
 288         platform_set_drvdata(pdev, leds_data);
 289
 290         return 0;
 291
 292 err:
 293         for (i = i - 1; i >= 0; i--)
 294                 delete_ns2_led(&leds_data[i]);
 295
 296         kfree(leds_data);
 297
 298         return ret;
 299 }
 300
 301 static int __devexit ns2_led_remove(struct platform_device *pdev)
 302 {
 303         int i;
 304         struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
 305         struct ns2_led_data *leds_data;
 306
 307         leds_data = platform_get_drvdata(pdev);
 308
 309         for (i = 0; i < pdata->num_leds; i++)
 310                 delete_ns2_led(&leds_data[i]);
 311
 312         kfree(leds_data);
 313         platform_set_drvdata(pdev, NULL);
 314
 315         return 0;
 316 }
 317
 318 static struct platform_driver ns2_led_driver = {
 319         .probe          = ns2_led_probe,
 320         .remove         = __devexit_p(ns2_led_remove),
 321         .driver         = {
 322                 .name   = "leds-ns2",
 323                 .owner  = THIS_MODULE,
 324         },
 325 };
 326
 327 module_platform_driver(ns2_led_driver);
 328
 329 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
 330 MODULE_DESCRIPTION("Network Space v2 LED driver");
 331 MODULE_LICENSE("GPL");
 332 MODULE_ALIAS("platform:leds-ns2");