package/button-hotplug/src/button-hotplug.c

   1 /*
   2  *  Button Hotplug driver
   3  *
   4  *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
   5  *
   6  *  Based on the diag.c - GPIO interface driver for Broadcom boards
   7  *    Copyright (C) 2006 Mike Baker <mbm@openwrt.org>,
   8  *    Copyright (C) 2006-2007 Felix Fietkau <nbd@openwrt.org>
   9  *    Copyright (C) 2008 Andy Boyett <agb@openwrt.org>
  10  *
  11  *  This program is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License version 2 as published
  13  *  by the Free Software Foundation.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/version.h>
  18 #include <linux/kmod.h>
  19 #include <linux/input.h>
  20
  21 #include <linux/workqueue.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/netlink.h>
  24 #include <net/sock.h>
  25
  26 #define DRV_NAME        "button-hotplug"
  27 #define DRV_VERSION     "0.4.0"
  28 #define DRV_DESC        "Button Hotplug driver"
  29
  30 #define BH_SKB_SIZE     2048
  31
  32 #define PFX     DRV_NAME ": "
  33
  34 #undef BH_DEBUG
  35
  36 #ifdef BH_DEBUG
  37 #define BH_DBG(fmt, args...) printk(KERN_DEBUG "%s: " fmt, DRV_NAME, ##args )
  38 #else
  39 #define BH_DBG(fmt, args...) do {} while (0)
  40 #endif
  41
  42 #define BH_ERR(fmt, args...) printk(KERN_ERR "%s: " fmt, DRV_NAME, ##args )
  43
  44 #ifndef BIT_MASK
  45 #define BIT_MASK(nr)            (1UL << ((nr) % BITS_PER_LONG))
  46 #endif
  47
  48 struct bh_priv {
  49         unsigned long           *seen;
  50         struct input_handle     handle;
  51 };
  52
  53 struct bh_event {
  54         const char              *name;
  55         char                    *action;
  56         unsigned long           seen;
  57
  58         struct sk_buff          *skb;
  59         struct work_struct      work;
  60 };
  61
  62 struct bh_map {
  63         unsigned int    code;
  64         const char      *name;
  65 };
  66
  67 extern struct sock *uevent_sock;
  68 extern u64 uevent_next_seqnum(void);
  69
  70 #define BH_MAP(_code, _name)            \
  71         {                               \
  72                 .code = (_code),        \
  73                 .name = (_name),        \
  74         }
  75
  76 static struct bh_map button_map[] = {
  77         BH_MAP(BTN_0,           "BTN_0"),
  78         BH_MAP(BTN_1,           "BTN_1"),
  79         BH_MAP(BTN_2,           "BTN_2"),
  80         BH_MAP(BTN_3,           "BTN_3"),
  81         BH_MAP(BTN_4,           "BTN_4"),
  82         BH_MAP(BTN_5,           "BTN_5"),
  83         BH_MAP(BTN_6,           "BTN_6"),
  84         BH_MAP(BTN_7,           "BTN_7"),
  85         BH_MAP(BTN_8,           "BTN_8"),
  86         BH_MAP(BTN_9,           "BTN_9"),
  87         BH_MAP(KEY_RESTART,     "reset"),
  88 #ifdef KEY_WPS_BUTTON
  89         BH_MAP(KEY_WPS_BUTTON,  "wps"),
  90 #endif /* KEY_WPS_BUTTON */
  91 };
  92
  93 /* -------------------------------------------------------------------------*/
  94
  95 static int bh_event_add_var(struct bh_event *event, int argv,
  96                 const char *format, ...)
  97 {
  98         static char buf[128];
  99         char *s;
 100         va_list args;
 101         int len;
 102
 103         if (argv)
 104                 return 0;
 105
 106         va_start(args, format);
 107         len = vsnprintf(buf, sizeof(buf), format, args);
 108         va_end(args);
 109
 110         if (len >= sizeof(buf)) {
 111                 BH_ERR("buffer size too small\n");
 112                 WARN_ON(1);
 113                 return -ENOMEM;
 114         }
 115
 116         s = skb_put(event->skb, len + 1);
 117         strcpy(s, buf);
 118
 119         BH_DBG("added variable '%s'\n", s);
 120
 121         return 0;
 122 }
 123
 124 static int button_hotplug_fill_event(struct bh_event *event)
 125 {
 126         int ret;
 127
 128         ret = bh_event_add_var(event, 0, "HOME=%s", "/");
 129         if (ret)
 130                 return ret;
 131
 132         ret = bh_event_add_var(event, 0, "PATH=%s",
 133                                         "/sbin:/bin:/usr/sbin:/usr/bin");
 134         if (ret)
 135                 return ret;
 136
 137         ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button");
 138         if (ret)
 139                 return ret;
 140
 141         ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
 142         if (ret)
 143                 return ret;
 144
 145         ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
 146         if (ret)
 147                 return ret;
 148
 149         ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
 150         if (ret)
 151                 return ret;
 152
 153         ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
 154
 155         return ret;
 156 }
 157
 158 static void button_hotplug_work(struct work_struct *work)
 159 {
 160         struct bh_event *event = container_of(work, struct bh_event, work);
 161         int ret = 0;
 162
 163         if (!uevent_sock)
 164                 goto out_free_event;
 165
 166         event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
 167         if (!event->skb)
 168                 goto out_free_event;
 169
 170         ret = bh_event_add_var(event, 0, "%s@", event->action);
 171         if (ret)
 172                 goto out_free_skb;
 173
 174         ret = button_hotplug_fill_event(event);
 175         if (ret)
 176                 goto out_free_skb;
 177
 178         NETLINK_CB(event->skb).dst_group = 1;
 179         netlink_broadcast(uevent_sock, event->skb, 0, 1, GFP_KERNEL);
 180
 181  out_free_skb:
 182         if (ret) {
 183                 BH_ERR("work error %d\n", ret);
 184                 kfree_skb(event->skb);
 185         }
 186  out_free_event:
 187         kfree(event);
 188 }
 189
 190 static int button_hotplug_create_event(const char *name, unsigned long seen,
 191                 int pressed)
 192 {
 193         struct bh_event *event;
 194
 195         BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
 196                 name, seen, pressed);
 197
 198         event = kzalloc(sizeof(*event), GFP_KERNEL);
 199         if (!event)
 200                 return -ENOMEM;
 201
 202         event->name = name;
 203         event->seen = seen;
 204         event->action = pressed ? "pressed" : "released";
 205
 206         INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
 207         schedule_work(&event->work);
 208
 209         return 0;
 210 }
 211
 212 /* -------------------------------------------------------------------------*/
 213
 214 #ifdef  CONFIG_HOTPLUG
 215 static int button_get_index(unsigned int code)
 216 {
 217         int i;
 218
 219         for (i = 0; i < ARRAY_SIZE(button_map); i++)
 220                 if (button_map[i].code == code)
 221                         return i;
 222
 223         return -1;
 224 }
 225 static void button_hotplug_event(struct input_handle *handle,
 226                            unsigned int type, unsigned int code, int value)
 227 {
 228         struct bh_priv *priv = handle->private;
 229         unsigned long seen = jiffies;
 230         int btn;
 231
 232         BH_DBG("event type=%u, code=%u, value=%d\n", type, code, value);
 233
 234         if (type != EV_KEY)
 235                 return;
 236
 237         btn = button_get_index(code);
 238         if (btn < 0)
 239                 return;
 240
 241         button_hotplug_create_event(button_map[btn].name,
 242                         (seen - priv->seen[btn]) / HZ, value);
 243         priv->seen[btn] = seen;
 244 }
 245 #else
 246 static void button_hotplug_event(struct input_handle *handle,
 247                            unsigned int type, unsigned int code, int value)
 248 {
 249 }
 250 #endif  /* CONFIG_HOTPLUG */
 251
 252 static int button_hotplug_connect(struct input_handler *handler,
 253                 struct input_dev *dev, const struct input_device_id *id)
 254 {
 255         struct bh_priv *priv;
 256         int ret;
 257         int i;
 258
 259         for (i = 0; i < ARRAY_SIZE(button_map); i++)
 260                 if (test_bit(button_map[i].code, dev->keybit))
 261                         break;
 262
 263         if (i == ARRAY_SIZE(button_map))
 264                 return -ENODEV;
 265
 266         priv = kzalloc(sizeof(*priv) +
 267                        (sizeof(unsigned long) * ARRAY_SIZE(button_map)),
 268                        GFP_KERNEL);
 269         if (!priv)
 270                 return -ENOMEM;
 271
 272         priv->seen = (unsigned long *) &priv[1];
 273         priv->handle.private = priv;
 274         priv->handle.dev = dev;
 275         priv->handle.handler = handler;
 276         priv->handle.name = DRV_NAME;
 277
 278         ret = input_register_handle(&priv->handle);
 279         if (ret)
 280                 goto err_free_priv;
 281
 282         ret = input_open_device(&priv->handle);
 283         if (ret)
 284                 goto err_unregister_handle;
 285
 286         BH_DBG("connected to %s\n", dev->name);
 287
 288         return 0;
 289
 290  err_unregister_handle:
 291         input_unregister_handle(&priv->handle);
 292
 293  err_free_priv:
 294         kfree(priv);
 295         return ret;
 296 }
 297
 298 static void button_hotplug_disconnect(struct input_handle *handle)
 299 {
 300         struct bh_priv *priv = handle->private;
 301
 302         input_close_device(handle);
 303         input_unregister_handle(handle);
 304
 305         kfree(priv);
 306 }
 307
 308 static const struct input_device_id button_hotplug_ids[] = {
 309         {
 310                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
 311                 .evbit = { BIT_MASK(EV_KEY) },
 312         },
 313         {
 314                 /* Terminating entry */
 315         },
 316 };
 317
 318 MODULE_DEVICE_TABLE(input, button_hotplug_ids);
 319
 320 static struct input_handler button_hotplug_handler = {
 321         .event =        button_hotplug_event,
 322         .connect =      button_hotplug_connect,
 323         .disconnect =   button_hotplug_disconnect,
 324         .name =         DRV_NAME,
 325         .id_table =     button_hotplug_ids,
 326 };
 327
 328 /* -------------------------------------------------------------------------*/
 329
 330 static int __init button_hotplug_init(void)
 331 {
 332         int ret;
 333
 334         printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
 335         ret = input_register_handler(&button_hotplug_handler);
 336         if (ret)
 337                 BH_ERR("unable to register input handler\n");
 338
 339         return ret;
 340 }
 341 module_init(button_hotplug_init);
 342
 343 static void __exit button_hotplug_exit(void)
 344 {
 345         input_unregister_handler(&button_hotplug_handler);
 346 }
 347 module_exit(button_hotplug_exit);
 348
 349 MODULE_DESCRIPTION(DRV_DESC);
 350 MODULE_VERSION(DRV_VERSION);
 351 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
 352 MODULE_LICENSE("GPL v2");
 353