xref: /linux/net/rfkill/input.c (revision fc8e1ead9314cf0e0f1922e661428b93d3a50d88)
1 /*
2  * Input layer to RF Kill interface connector
3  *
4  * Copyright (c) 2007 Dmitry Torokhov
5  * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License version 2 as published
9  * by the Free Software Foundation.
10  *
11  * If you ever run into a situation in which you have a SW_ type rfkill
12  * input device, then you can revive code that was removed in the patch
13  * "rfkill-input: remove unused code".
14  */
15 
16 #include <linux/input.h>
17 #include <linux/slab.h>
18 #include <linux/workqueue.h>
19 #include <linux/init.h>
20 #include <linux/rfkill.h>
21 #include <linux/sched.h>
22 
23 #include "rfkill.h"
24 
25 enum rfkill_input_master_mode {
26 	RFKILL_INPUT_MASTER_UNLOCK = 0,
27 	RFKILL_INPUT_MASTER_RESTORE = 1,
28 	RFKILL_INPUT_MASTER_UNBLOCKALL = 2,
29 	NUM_RFKILL_INPUT_MASTER_MODES
30 };
31 
32 /* Delay (in ms) between consecutive switch ops */
33 #define RFKILL_OPS_DELAY 200
34 
35 static enum rfkill_input_master_mode rfkill_master_switch_mode =
36 					RFKILL_INPUT_MASTER_UNBLOCKALL;
37 module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
38 MODULE_PARM_DESC(master_switch_mode,
39 	"SW_RFKILL_ALL ON should: 0=do nothing (only unlock); 1=restore; 2=unblock all");
40 
41 static spinlock_t rfkill_op_lock;
42 static bool rfkill_op_pending;
43 static unsigned long rfkill_sw_pending[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
44 static unsigned long rfkill_sw_state[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
45 
46 enum rfkill_sched_op {
47 	RFKILL_GLOBAL_OP_EPO = 0,
48 	RFKILL_GLOBAL_OP_RESTORE,
49 	RFKILL_GLOBAL_OP_UNLOCK,
50 	RFKILL_GLOBAL_OP_UNBLOCK,
51 };
52 
53 static enum rfkill_sched_op rfkill_master_switch_op;
54 static enum rfkill_sched_op rfkill_op;
55 
56 static void __rfkill_handle_global_op(enum rfkill_sched_op op)
57 {
58 	unsigned int i;
59 
60 	switch (op) {
61 	case RFKILL_GLOBAL_OP_EPO:
62 		rfkill_epo();
63 		break;
64 	case RFKILL_GLOBAL_OP_RESTORE:
65 		rfkill_restore_states();
66 		break;
67 	case RFKILL_GLOBAL_OP_UNLOCK:
68 		rfkill_remove_epo_lock();
69 		break;
70 	case RFKILL_GLOBAL_OP_UNBLOCK:
71 		rfkill_remove_epo_lock();
72 		for (i = 0; i < NUM_RFKILL_TYPES; i++)
73 			rfkill_switch_all(i, false);
74 		break;
75 	default:
76 		/* memory corruption or bug, fail safely */
77 		rfkill_epo();
78 		WARN(1, "Unknown requested operation %d! "
79 			"rfkill Emergency Power Off activated\n",
80 			op);
81 	}
82 }
83 
84 static void __rfkill_handle_normal_op(const enum rfkill_type type,
85 				      const bool complement)
86 {
87 	bool blocked;
88 
89 	blocked = rfkill_get_global_sw_state(type);
90 	if (complement)
91 		blocked = !blocked;
92 
93 	rfkill_switch_all(type, blocked);
94 }
95 
96 static void rfkill_op_handler(struct work_struct *work)
97 {
98 	unsigned int i;
99 	bool c;
100 
101 	spin_lock_irq(&rfkill_op_lock);
102 	do {
103 		if (rfkill_op_pending) {
104 			enum rfkill_sched_op op = rfkill_op;
105 			rfkill_op_pending = false;
106 			memset(rfkill_sw_pending, 0,
107 				sizeof(rfkill_sw_pending));
108 			spin_unlock_irq(&rfkill_op_lock);
109 
110 			__rfkill_handle_global_op(op);
111 
112 			spin_lock_irq(&rfkill_op_lock);
113 
114 			/*
115 			 * handle global ops first -- during unlocked period
116 			 * we might have gotten a new global op.
117 			 */
118 			if (rfkill_op_pending)
119 				continue;
120 		}
121 
122 		if (rfkill_is_epo_lock_active())
123 			continue;
124 
125 		for (i = 0; i < NUM_RFKILL_TYPES; i++) {
126 			if (__test_and_clear_bit(i, rfkill_sw_pending)) {
127 				c = __test_and_clear_bit(i, rfkill_sw_state);
128 				spin_unlock_irq(&rfkill_op_lock);
129 
130 				__rfkill_handle_normal_op(i, c);
131 
132 				spin_lock_irq(&rfkill_op_lock);
133 			}
134 		}
135 	} while (rfkill_op_pending);
136 	spin_unlock_irq(&rfkill_op_lock);
137 }
138 
139 static DECLARE_DELAYED_WORK(rfkill_op_work, rfkill_op_handler);
140 static unsigned long rfkill_last_scheduled;
141 
142 static unsigned long rfkill_ratelimit(const unsigned long last)
143 {
144 	const unsigned long delay = msecs_to_jiffies(RFKILL_OPS_DELAY);
145 	return (time_after(jiffies, last + delay)) ? 0 : delay;
146 }
147 
148 static void rfkill_schedule_ratelimited(void)
149 {
150 	if (delayed_work_pending(&rfkill_op_work))
151 		return;
152 	schedule_delayed_work(&rfkill_op_work,
153 			      rfkill_ratelimit(rfkill_last_scheduled));
154 	rfkill_last_scheduled = jiffies;
155 }
156 
157 static void rfkill_schedule_global_op(enum rfkill_sched_op op)
158 {
159 	unsigned long flags;
160 
161 	spin_lock_irqsave(&rfkill_op_lock, flags);
162 	rfkill_op = op;
163 	rfkill_op_pending = true;
164 	if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
165 		/* bypass the limiter for EPO */
166 		cancel_delayed_work(&rfkill_op_work);
167 		schedule_delayed_work(&rfkill_op_work, 0);
168 		rfkill_last_scheduled = jiffies;
169 	} else
170 		rfkill_schedule_ratelimited();
171 	spin_unlock_irqrestore(&rfkill_op_lock, flags);
172 }
173 
174 static void rfkill_schedule_toggle(enum rfkill_type type)
175 {
176 	unsigned long flags;
177 
178 	if (rfkill_is_epo_lock_active())
179 		return;
180 
181 	spin_lock_irqsave(&rfkill_op_lock, flags);
182 	if (!rfkill_op_pending) {
183 		__set_bit(type, rfkill_sw_pending);
184 		__change_bit(type, rfkill_sw_state);
185 		rfkill_schedule_ratelimited();
186 	}
187 	spin_unlock_irqrestore(&rfkill_op_lock, flags);
188 }
189 
190 static void rfkill_schedule_evsw_rfkillall(int state)
191 {
192 	if (state)
193 		rfkill_schedule_global_op(rfkill_master_switch_op);
194 	else
195 		rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
196 }
197 
198 static void rfkill_event(struct input_handle *handle, unsigned int type,
199 			unsigned int code, int data)
200 {
201 	if (type == EV_KEY && data == 1) {
202 		switch (code) {
203 		case KEY_WLAN:
204 			rfkill_schedule_toggle(RFKILL_TYPE_WLAN);
205 			break;
206 		case KEY_BLUETOOTH:
207 			rfkill_schedule_toggle(RFKILL_TYPE_BLUETOOTH);
208 			break;
209 		case KEY_UWB:
210 			rfkill_schedule_toggle(RFKILL_TYPE_UWB);
211 			break;
212 		case KEY_WIMAX:
213 			rfkill_schedule_toggle(RFKILL_TYPE_WIMAX);
214 			break;
215 		}
216 	} else if (type == EV_SW && code == SW_RFKILL_ALL)
217 		rfkill_schedule_evsw_rfkillall(data);
218 }
219 
220 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
221 			  const struct input_device_id *id)
222 {
223 	struct input_handle *handle;
224 	int error;
225 
226 	handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
227 	if (!handle)
228 		return -ENOMEM;
229 
230 	handle->dev = dev;
231 	handle->handler = handler;
232 	handle->name = "rfkill";
233 
234 	/* causes rfkill_start() to be called */
235 	error = input_register_handle(handle);
236 	if (error)
237 		goto err_free_handle;
238 
239 	error = input_open_device(handle);
240 	if (error)
241 		goto err_unregister_handle;
242 
243 	return 0;
244 
245  err_unregister_handle:
246 	input_unregister_handle(handle);
247  err_free_handle:
248 	kfree(handle);
249 	return error;
250 }
251 
252 static void rfkill_start(struct input_handle *handle)
253 {
254 	/*
255 	 * Take event_lock to guard against configuration changes, we
256 	 * should be able to deal with concurrency with rfkill_event()
257 	 * just fine (which event_lock will also avoid).
258 	 */
259 	spin_lock_irq(&handle->dev->event_lock);
260 
261 	if (test_bit(EV_SW, handle->dev->evbit) &&
262 	    test_bit(SW_RFKILL_ALL, handle->dev->swbit))
263 		rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
264 							handle->dev->sw));
265 
266 	spin_unlock_irq(&handle->dev->event_lock);
267 }
268 
269 static void rfkill_disconnect(struct input_handle *handle)
270 {
271 	input_close_device(handle);
272 	input_unregister_handle(handle);
273 	kfree(handle);
274 }
275 
276 static const struct input_device_id rfkill_ids[] = {
277 	{
278 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
279 		.evbit = { BIT_MASK(EV_KEY) },
280 		.keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
281 	},
282 	{
283 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
284 		.evbit = { BIT_MASK(EV_KEY) },
285 		.keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
286 	},
287 	{
288 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
289 		.evbit = { BIT_MASK(EV_KEY) },
290 		.keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
291 	},
292 	{
293 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
294 		.evbit = { BIT_MASK(EV_KEY) },
295 		.keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
296 	},
297 	{
298 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
299 		.evbit = { BIT(EV_SW) },
300 		.swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
301 	},
302 	{ }
303 };
304 
305 static struct input_handler rfkill_handler = {
306 	.name =	"rfkill",
307 	.event = rfkill_event,
308 	.connect = rfkill_connect,
309 	.start = rfkill_start,
310 	.disconnect = rfkill_disconnect,
311 	.id_table = rfkill_ids,
312 };
313 
314 int __init rfkill_handler_init(void)
315 {
316 	switch (rfkill_master_switch_mode) {
317 	case RFKILL_INPUT_MASTER_UNBLOCKALL:
318 		rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNBLOCK;
319 		break;
320 	case RFKILL_INPUT_MASTER_RESTORE:
321 		rfkill_master_switch_op = RFKILL_GLOBAL_OP_RESTORE;
322 		break;
323 	case RFKILL_INPUT_MASTER_UNLOCK:
324 		rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNLOCK;
325 		break;
326 	default:
327 		return -EINVAL;
328 	}
329 
330 	spin_lock_init(&rfkill_op_lock);
331 
332 	/* Avoid delay at first schedule */
333 	rfkill_last_scheduled =
334 			jiffies - msecs_to_jiffies(RFKILL_OPS_DELAY) - 1;
335 	return input_register_handler(&rfkill_handler);
336 }
337 
338 void __exit rfkill_handler_exit(void)
339 {
340 	input_unregister_handler(&rfkill_handler);
341 	cancel_delayed_work_sync(&rfkill_op_work);
342 }
343