package/kernel/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@nbd.name>
   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 <linux/kobject.h>
  25
  26 #define DRV_NAME        "button-hotplug"
  27 #define DRV_VERSION     "0.4.1"
  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 u64 uevent_next_seqnum(void);
  68
  69 #define BH_MAP(_code, _name)            \
  70         {                               \
  71                 .code = (_code),        \
  72                 .name = (_name),        \
  73         }
  74
  75 static struct bh_map button_map[] = {
  76         BH_MAP(BTN_0,           "BTN_0"),
  77         BH_MAP(BTN_1,           "BTN_1"),
  78         BH_MAP(BTN_2,           "BTN_2"),
  79         BH_MAP(BTN_3,           "BTN_3"),
  80         BH_MAP(BTN_4,           "BTN_4"),
  81         BH_MAP(BTN_5,           "BTN_5"),
  82         BH_MAP(BTN_6,           "BTN_6"),
  83         BH_MAP(BTN_7,           "BTN_7"),
  84         BH_MAP(BTN_8,           "BTN_8"),
  85         BH_MAP(BTN_9,           "BTN_9"),
  86         BH_MAP(KEY_RESTART,     "reset"),
  87         BH_MAP(KEY_POWER,       "power"),
  88         BH_MAP(KEY_POWER2,      "reboot"),
  89         BH_MAP(KEY_RFKILL,      "rfkill"),
  90         BH_MAP(KEY_WPS_BUTTON,  "wps"),
  91         BH_MAP(KEY_WIMAX,       "wwan"),
  92 };
  93
  94 /* -------------------------------------------------------------------------*/
  95
  96 static int bh_event_add_var(struct bh_event *event, int argv,
  97                 const char *format, ...)
  98 {
  99         static char buf[128];
 100         char *s;
 101         va_list args;
 102         int len;
 103
 104         if (argv)
 105                 return 0;
 106
 107         va_start(args, format);
 108         len = vsnprintf(buf, sizeof(buf), format, args);
 109         va_end(args);
 110
 111         if (len >= sizeof(buf)) {
 112                 BH_ERR("buffer size too small\n");
 113                 WARN_ON(1);
 114                 return -ENOMEM;
 115         }
 116
 117         s = skb_put(event->skb, len + 1);
 118         strcpy(s, buf);
 119
 120         BH_DBG("added variable '%s'\n", s);
 121
 122         return 0;
 123 }
 124
 125 static int button_hotplug_fill_event(struct bh_event *event)
 126 {
 127         int ret;
 128
 129         ret = bh_event_add_var(event, 0, "HOME=%s", "/");
 130         if (ret)
 131                 return ret;
 132
 133         ret = bh_event_add_var(event, 0, "PATH=%s",
 134                                         "/sbin:/bin:/usr/sbin:/usr/bin");
 135         if (ret)
 136                 return ret;
 137
 138         ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button");
 139         if (ret)
 140                 return ret;
 141
 142         ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
 143         if (ret)
 144                 return ret;
 145
 146         ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
 147         if (ret)
 148                 return ret;
 149
 150         ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
 151         if (ret)
 152                 return ret;
 153
 154         ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
 155
 156         return ret;
 157 }
 158
 159 static void button_hotplug_work(struct work_struct *work)
 160 {
 161         struct bh_event *event = container_of(work, struct bh_event, work);
 162         int ret = 0;
 163
 164         event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
 165         if (!event->skb)
 166                 goto out_free_event;
 167
 168         ret = bh_event_add_var(event, 0, "%s@", event->action);
 169         if (ret)
 170                 goto out_free_skb;
 171
 172         ret = button_hotplug_fill_event(event);
 173         if (ret)
 174                 goto out_free_skb;
 175
 176         NETLINK_CB(event->skb).dst_group = 1;
 177         broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
 178
 179  out_free_skb:
 180         if (ret) {
 181                 BH_ERR("work error %d\n", ret);
 182                 kfree_skb(event->skb);
 183         }
 184  out_free_event:
 185         kfree(event);
 186 }
 187
 188 static int button_hotplug_create_event(const char *name, unsigned long seen,
 189                 int pressed)
 190 {
 191         struct bh_event *event;
 192
 193         BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
 194                 name, seen, pressed);
 195
 196         event = kzalloc(sizeof(*event), GFP_KERNEL);
 197         if (!event)
 198                 return -ENOMEM;
 199
 200         event->name = name;
 201         event->seen = seen;
 202         event->action = pressed ? "pressed" : "released";
 203
 204         INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
 205         schedule_work(&event->work);
 206
 207         return 0;
 208 }
 209
 210 /* -------------------------------------------------------------------------*/
 211
 212 static int button_get_index(unsigned int code)
 213 {
 214         int i;
 215
 216         for (i = 0; i < ARRAY_SIZE(button_map); i++)
 217                 if (button_map[i].code == code)
 218                         return i;
 219
 220         return -1;
 221 }
 222 static void button_hotplug_event(struct input_handle *handle,
 223                            unsigned int type, unsigned int code, int value)
 224 {
 225         struct bh_priv *priv = handle->private;
 226         unsigned long seen = jiffies;
 227         int btn;
 228
 229         BH_DBG("event type=%u, code=%u, value=%d\n", type, code, value);
 230
 231         if (type != EV_KEY)
 232                 return;
 233
 234         btn = button_get_index(code);
 235         if (btn < 0)
 236                 return;
 237
 238         button_hotplug_create_event(button_map[btn].name,
 239                         (seen - priv->seen[btn]) / HZ, value);
 240         priv->seen[btn] = seen;
 241 }
 242
 243 static int button_hotplug_connect(struct input_handler *handler,
 244                 struct input_dev *dev, const struct input_device_id *id)
 245 {
 246         struct bh_priv *priv;
 247         int ret;
 248         int i;
 249
 250         for (i = 0; i < ARRAY_SIZE(button_map); i++)
 251                 if (test_bit(button_map[i].code, dev->keybit))
 252                         break;
 253
 254         if (i == ARRAY_SIZE(button_map))
 255                 return -ENODEV;
 256
 257         priv = kzalloc(sizeof(*priv) +
 258                        (sizeof(unsigned long) * ARRAY_SIZE(button_map)),
 259                        GFP_KERNEL);
 260         if (!priv)
 261                 return -ENOMEM;
 262
 263         priv->seen = (unsigned long *) &priv[1];
 264         priv->handle.private = priv;
 265         priv->handle.dev = dev;
 266         priv->handle.handler = handler;
 267         priv->handle.name = DRV_NAME;
 268
 269         ret = input_register_handle(&priv->handle);
 270         if (ret)
 271                 goto err_free_priv;
 272
 273         ret = input_open_device(&priv->handle);
 274         if (ret)
 275                 goto err_unregister_handle;
 276
 277         BH_DBG("connected to %s\n", dev->name);
 278
 279         return 0;
 280
 281  err_unregister_handle:
 282         input_unregister_handle(&priv->handle);
 283
 284  err_free_priv:
 285         kfree(priv);
 286         return ret;
 287 }
 288
 289 static void button_hotplug_disconnect(struct input_handle *handle)
 290 {
 291         struct bh_priv *priv = handle->private;
 292
 293         input_close_device(handle);
 294         input_unregister_handle(handle);
 295
 296         kfree(priv);
 297 }
 298
 299 static const struct input_device_id button_hotplug_ids[] = {
 300         {
 301                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
 302                 .evbit = { BIT_MASK(EV_KEY) },
 303         },
 304         {
 305                 /* Terminating entry */
 306         },
 307 };
 308
 309 MODULE_DEVICE_TABLE(input, button_hotplug_ids);
 310
 311 static struct input_handler button_hotplug_handler = {
 312         .event =        button_hotplug_event,
 313         .connect =      button_hotplug_connect,
 314         .disconnect =   button_hotplug_disconnect,
 315         .name =         DRV_NAME,
 316         .id_table =     button_hotplug_ids,
 317 };
 318
 319 /* -------------------------------------------------------------------------*/
 320
 321 static int __init button_hotplug_init(void)
 322 {
 323         int ret;
 324
 325         printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
 326         ret = input_register_handler(&button_hotplug_handler);
 327         if (ret)
 328                 BH_ERR("unable to register input handler\n");
 329
 330         return ret;
 331 }
 332 module_init(button_hotplug_init);
 333
 334 static void __exit button_hotplug_exit(void)
 335 {
 336         input_unregister_handler(&button_hotplug_handler);
 337 }
 338 module_exit(button_hotplug_exit);
 339
 340 MODULE_DESCRIPTION(DRV_DESC);
 341 MODULE_VERSION(DRV_VERSION);
 342 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
 343 MODULE_LICENSE("GPL v2");
 344