Root/package/system/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 <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
48struct bh_priv {
49    unsigned long *seen;
50    struct input_handle handle;
51};
52
53struct 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
62struct bh_map {
63    unsigned int code;
64    const char *name;
65};
66
67extern u64 uevent_next_seqnum(void);
68
69#define BH_MAP(_code, _name) \
70    { \
71        .code = (_code), \
72        .name = (_name), \
73    }
74
75static 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#ifdef KEY_WPS_BUTTON
88    BH_MAP(KEY_WPS_BUTTON, "wps"),
89#endif /* KEY_WPS_BUTTON */
90};
91
92/* -------------------------------------------------------------------------*/
93
94static int bh_event_add_var(struct bh_event *event, int argv,
95        const char *format, ...)
96{
97    static char buf[128];
98    char *s;
99    va_list args;
100    int len;
101
102    if (argv)
103        return 0;
104
105    va_start(args, format);
106    len = vsnprintf(buf, sizeof(buf), format, args);
107    va_end(args);
108
109    if (len >= sizeof(buf)) {
110        BH_ERR("buffer size too small\n");
111        WARN_ON(1);
112        return -ENOMEM;
113    }
114
115    s = skb_put(event->skb, len + 1);
116    strcpy(s, buf);
117
118    BH_DBG("added variable '%s'\n", s);
119
120    return 0;
121}
122
123static int button_hotplug_fill_event(struct bh_event *event)
124{
125    int ret;
126
127    ret = bh_event_add_var(event, 0, "HOME=%s", "/");
128    if (ret)
129        return ret;
130
131    ret = bh_event_add_var(event, 0, "PATH=%s",
132                    "/sbin:/bin:/usr/sbin:/usr/bin");
133    if (ret)
134        return ret;
135
136    ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button");
137    if (ret)
138        return ret;
139
140    ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
141    if (ret)
142        return ret;
143
144    ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
145    if (ret)
146        return ret;
147
148    ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
149    if (ret)
150        return ret;
151
152    ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
153
154    return ret;
155}
156
157static void button_hotplug_work(struct work_struct *work)
158{
159    struct bh_event *event = container_of(work, struct bh_event, work);
160    int ret = 0;
161
162    event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
163    if (!event->skb)
164        goto out_free_event;
165
166    ret = bh_event_add_var(event, 0, "%s@", event->action);
167    if (ret)
168        goto out_free_skb;
169
170    ret = button_hotplug_fill_event(event);
171    if (ret)
172        goto out_free_skb;
173
174    NETLINK_CB(event->skb).dst_group = 1;
175    broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
176
177 out_free_skb:
178    if (ret) {
179        BH_ERR("work error %d\n", ret);
180        kfree_skb(event->skb);
181    }
182 out_free_event:
183    kfree(event);
184}
185
186static int button_hotplug_create_event(const char *name, unsigned long seen,
187        int pressed)
188{
189    struct bh_event *event;
190
191    BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
192        name, seen, pressed);
193
194    event = kzalloc(sizeof(*event), GFP_KERNEL);
195    if (!event)
196        return -ENOMEM;
197
198    event->name = name;
199    event->seen = seen;
200    event->action = pressed ? "pressed" : "released";
201
202    INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
203    schedule_work(&event->work);
204
205    return 0;
206}
207
208/* -------------------------------------------------------------------------*/
209
210#ifdef CONFIG_HOTPLUG
211static int button_get_index(unsigned int code)
212{
213    int i;
214
215    for (i = 0; i < ARRAY_SIZE(button_map); i++)
216        if (button_map[i].code == code)
217            return i;
218
219    return -1;
220}
221static void button_hotplug_event(struct input_handle *handle,
222               unsigned int type, unsigned int code, int value)
223{
224    struct bh_priv *priv = handle->private;
225    unsigned long seen = jiffies;
226    int btn;
227
228    BH_DBG("event type=%u, code=%u, value=%d\n", type, code, value);
229
230    if (type != EV_KEY)
231        return;
232
233    btn = button_get_index(code);
234    if (btn < 0)
235        return;
236
237    button_hotplug_create_event(button_map[btn].name,
238            (seen - priv->seen[btn]) / HZ, value);
239    priv->seen[btn] = seen;
240}
241#else
242static void button_hotplug_event(struct input_handle *handle,
243               unsigned int type, unsigned int code, int value)
244{
245}
246#endif /* CONFIG_HOTPLUG */
247
248static int button_hotplug_connect(struct input_handler *handler,
249        struct input_dev *dev, const struct input_device_id *id)
250{
251    struct bh_priv *priv;
252    int ret;
253    int i;
254
255    for (i = 0; i < ARRAY_SIZE(button_map); i++)
256        if (test_bit(button_map[i].code, dev->keybit))
257            break;
258
259    if (i == ARRAY_SIZE(button_map))
260        return -ENODEV;
261
262    priv = kzalloc(sizeof(*priv) +
263               (sizeof(unsigned long) * ARRAY_SIZE(button_map)),
264               GFP_KERNEL);
265    if (!priv)
266        return -ENOMEM;
267
268    priv->seen = (unsigned long *) &priv[1];
269    priv->handle.private = priv;
270    priv->handle.dev = dev;
271    priv->handle.handler = handler;
272    priv->handle.name = DRV_NAME;
273
274    ret = input_register_handle(&priv->handle);
275    if (ret)
276        goto err_free_priv;
277
278    ret = input_open_device(&priv->handle);
279    if (ret)
280        goto err_unregister_handle;
281
282    BH_DBG("connected to %s\n", dev->name);
283
284    return 0;
285
286 err_unregister_handle:
287    input_unregister_handle(&priv->handle);
288
289 err_free_priv:
290    kfree(priv);
291    return ret;
292}
293
294static void button_hotplug_disconnect(struct input_handle *handle)
295{
296    struct bh_priv *priv = handle->private;
297
298    input_close_device(handle);
299    input_unregister_handle(handle);
300
301    kfree(priv);
302}
303
304static const struct input_device_id button_hotplug_ids[] = {
305    {
306                .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
307                .evbit = { BIT_MASK(EV_KEY) },
308        },
309    {
310        /* Terminating entry */
311    },
312};
313
314MODULE_DEVICE_TABLE(input, button_hotplug_ids);
315
316static struct input_handler button_hotplug_handler = {
317    .event = button_hotplug_event,
318    .connect = button_hotplug_connect,
319    .disconnect = button_hotplug_disconnect,
320    .name = DRV_NAME,
321    .id_table = button_hotplug_ids,
322};
323
324/* -------------------------------------------------------------------------*/
325
326static int __init button_hotplug_init(void)
327{
328    int ret;
329
330    printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
331    ret = input_register_handler(&button_hotplug_handler);
332    if (ret)
333        BH_ERR("unable to register input handler\n");
334
335    return ret;
336}
337module_init(button_hotplug_init);
338
339static void __exit button_hotplug_exit(void)
340{
341    input_unregister_handler(&button_hotplug_handler);
342}
343module_exit(button_hotplug_exit);
344
345MODULE_DESCRIPTION(DRV_DESC);
346MODULE_VERSION(DRV_VERSION);
347MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
348MODULE_LICENSE("GPL v2");
349
350

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