xref: /openbmc/linux/net/rfkill/input.c (revision ae213c44)
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/moduleparam.h>
19 #include <linux/workqueue.h>
20 #include <linux/init.h>
21 #include <linux/rfkill.h>
22 #include <linux/sched.h>
23 
24 #include "rfkill.h"
25 
26 enum rfkill_input_master_mode {
27 	RFKILL_INPUT_MASTER_UNLOCK = 0,
28 	RFKILL_INPUT_MASTER_RESTORE = 1,
29 	RFKILL_INPUT_MASTER_UNBLOCKALL = 2,
30 	NUM_RFKILL_INPUT_MASTER_MODES
31 };
32 
33 /* Delay (in ms) between consecutive switch ops */
34 #define RFKILL_OPS_DELAY 200
35 
36 static enum rfkill_input_master_mode rfkill_master_switch_mode =
37 					RFKILL_INPUT_MASTER_UNBLOCKALL;
38 module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
39 MODULE_PARM_DESC(master_switch_mode,
40 	"SW_RFKILL_ALL ON should: 0=do nothing (only unlock); 1=restore; 2=unblock all");
41 
42 static spinlock_t rfkill_op_lock;
43 static bool rfkill_op_pending;
44 static unsigned long rfkill_sw_pending[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
45 static unsigned long rfkill_sw_state[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
46 
47 enum rfkill_sched_op {
48 	RFKILL_GLOBAL_OP_EPO = 0,
49 	RFKILL_GLOBAL_OP_RESTORE,
50 	RFKILL_GLOBAL_OP_UNLOCK,
51 	RFKILL_GLOBAL_OP_UNBLOCK,
52 };
53 
54 static enum rfkill_sched_op rfkill_master_switch_op;
55 static enum rfkill_sched_op rfkill_op;
56 
57 static void __rfkill_handle_global_op(enum rfkill_sched_op op)
58 {
59 	unsigned int i;
60 
61 	switch (op) {
62 	case RFKILL_GLOBAL_OP_EPO:
63 		rfkill_epo();
64 		break;
65 	case RFKILL_GLOBAL_OP_RESTORE:
66 		rfkill_restore_states();
67 		break;
68 	case RFKILL_GLOBAL_OP_UNLOCK:
69 		rfkill_remove_epo_lock();
70 		break;
71 	case RFKILL_GLOBAL_OP_UNBLOCK:
72 		rfkill_remove_epo_lock();
73 		for (i = 0; i < NUM_RFKILL_TYPES; i++)
74 			rfkill_switch_all(i, false);
75 		break;
76 	default:
77 		/* memory corruption or bug, fail safely */
78 		rfkill_epo();
79 		WARN(1, "Unknown requested operation %d! "
80 			"rfkill Emergency Power Off activated\n",
81 			op);
82 	}
83 }
84 
85 static void __rfkill_handle_normal_op(const enum rfkill_type type,
86 				      const bool complement)
87 {
88 	bool blocked;
89 
90 	blocked = rfkill_get_global_sw_state(type);
91 	if (complement)
92 		blocked = !blocked;
93 
94 	rfkill_switch_all(type, blocked);
95 }
96 
97 static void rfkill_op_handler(struct work_struct *work)
98 {
99 	unsigned int i;
100 	bool c;
101 
102 	spin_lock_irq(&rfkill_op_lock);
103 	do {
104 		if (rfkill_op_pending) {
105 			enum rfkill_sched_op op = rfkill_op;
106 			rfkill_op_pending = false;
107 			memset(rfkill_sw_pending, 0,
108 				sizeof(rfkill_sw_pending));
109 			spin_unlock_irq(&rfkill_op_lock);
110 
111 			__rfkill_handle_global_op(op);
112 
113 			spin_lock_irq(&rfkill_op_lock);
114 
115 			/*
116 			 * handle global ops first -- during unlocked period
117 			 * we might have gotten a new global op.
118 			 */
119 			if (rfkill_op_pending)
120 				continue;
121 		}
122 
123 		if (rfkill_is_epo_lock_active())
124 			continue;
125 
126 		for (i = 0; i < NUM_RFKILL_TYPES; i++) {
127 			if (__test_and_clear_bit(i, rfkill_sw_pending)) {
128 				c = __test_and_clear_bit(i, rfkill_sw_state);
129 				spin_unlock_irq(&rfkill_op_lock);
130 
131 				__rfkill_handle_normal_op(i, c);
132 
133 				spin_lock_irq(&rfkill_op_lock);
134 			}
135 		}
136 	} while (rfkill_op_pending);
137 	spin_unlock_irq(&rfkill_op_lock);
138 }
139 
140 static DECLARE_DELAYED_WORK(rfkill_op_work, rfkill_op_handler);
141 static unsigned long rfkill_last_scheduled;
142 
143 static unsigned long rfkill_ratelimit(const unsigned long last)
144 {
145 	const unsigned long delay = msecs_to_jiffies(RFKILL_OPS_DELAY);
146 	return time_after(jiffies, last + delay) ? 0 : delay;
147 }
148 
149 static void rfkill_schedule_ratelimited(void)
150 {
151 	if (schedule_delayed_work(&rfkill_op_work,
152 				  rfkill_ratelimit(rfkill_last_scheduled)))
153 		rfkill_last_scheduled = jiffies;
154 }
155 
156 static void rfkill_schedule_global_op(enum rfkill_sched_op op)
157 {
158 	unsigned long flags;
159 
160 	spin_lock_irqsave(&rfkill_op_lock, flags);
161 	rfkill_op = op;
162 	rfkill_op_pending = true;
163 	if (op == RFKILL_GLOBAL_OP_EPO && !rfkill_is_epo_lock_active()) {
164 		/* bypass the limiter for EPO */
165 		mod_delayed_work(system_wq, &rfkill_op_work, 0);
166 		rfkill_last_scheduled = jiffies;
167 	} else
168 		rfkill_schedule_ratelimited();
169 	spin_unlock_irqrestore(&rfkill_op_lock, flags);
170 }
171 
172 static void rfkill_schedule_toggle(enum rfkill_type type)
173 {
174 	unsigned long flags;
175 
176 	if (rfkill_is_epo_lock_active())
177 		return;
178 
179 	spin_lock_irqsave(&rfkill_op_lock, flags);
180 	if (!rfkill_op_pending) {
181 		__set_bit(type, rfkill_sw_pending);
182 		__change_bit(type, rfkill_sw_state);
183 		rfkill_schedule_ratelimited();
184 	}
185 	spin_unlock_irqrestore(&rfkill_op_lock, flags);
186 }
187 
188 static void rfkill_schedule_evsw_rfkillall(int state)
189 {
190 	if (state)
191 		rfkill_schedule_global_op(rfkill_master_switch_op);
192 	else
193 		rfkill_schedule_global_op(RFKILL_GLOBAL_OP_EPO);
194 }
195 
196 static void rfkill_event(struct input_handle *handle, unsigned int type,
197 			unsigned int code, int data)
198 {
199 	if (type == EV_KEY && data == 1) {
200 		switch (code) {
201 		case KEY_WLAN:
202 			rfkill_schedule_toggle(RFKILL_TYPE_WLAN);
203 			break;
204 		case KEY_BLUETOOTH:
205 			rfkill_schedule_toggle(RFKILL_TYPE_BLUETOOTH);
206 			break;
207 		case KEY_UWB:
208 			rfkill_schedule_toggle(RFKILL_TYPE_UWB);
209 			break;
210 		case KEY_WIMAX:
211 			rfkill_schedule_toggle(RFKILL_TYPE_WIMAX);
212 			break;
213 		case KEY_RFKILL:
214 			rfkill_schedule_toggle(RFKILL_TYPE_ALL);
215 			break;
216 		}
217 	} else if (type == EV_SW && code == SW_RFKILL_ALL)
218 		rfkill_schedule_evsw_rfkillall(data);
219 }
220 
221 static int rfkill_connect(struct input_handler *handler, struct input_dev *dev,
222 			  const struct input_device_id *id)
223 {
224 	struct input_handle *handle;
225 	int error;
226 
227 	handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
228 	if (!handle)
229 		return -ENOMEM;
230 
231 	handle->dev = dev;
232 	handle->handler = handler;
233 	handle->name = "rfkill";
234 
235 	/* causes rfkill_start() to be called */
236 	error = input_register_handle(handle);
237 	if (error)
238 		goto err_free_handle;
239 
240 	error = input_open_device(handle);
241 	if (error)
242 		goto err_unregister_handle;
243 
244 	return 0;
245 
246  err_unregister_handle:
247 	input_unregister_handle(handle);
248  err_free_handle:
249 	kfree(handle);
250 	return error;
251 }
252 
253 static void rfkill_start(struct input_handle *handle)
254 {
255 	/*
256 	 * Take event_lock to guard against configuration changes, we
257 	 * should be able to deal with concurrency with rfkill_event()
258 	 * just fine (which event_lock will also avoid).
259 	 */
260 	spin_lock_irq(&handle->dev->event_lock);
261 
262 	if (test_bit(EV_SW, handle->dev->evbit) &&
263 	    test_bit(SW_RFKILL_ALL, handle->dev->swbit))
264 		rfkill_schedule_evsw_rfkillall(test_bit(SW_RFKILL_ALL,
265 							handle->dev->sw));
266 
267 	spin_unlock_irq(&handle->dev->event_lock);
268 }
269 
270 static void rfkill_disconnect(struct input_handle *handle)
271 {
272 	input_close_device(handle);
273 	input_unregister_handle(handle);
274 	kfree(handle);
275 }
276 
277 static const struct input_device_id rfkill_ids[] = {
278 	{
279 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
280 		.evbit = { BIT_MASK(EV_KEY) },
281 		.keybit = { [BIT_WORD(KEY_WLAN)] = BIT_MASK(KEY_WLAN) },
282 	},
283 	{
284 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
285 		.evbit = { BIT_MASK(EV_KEY) },
286 		.keybit = { [BIT_WORD(KEY_BLUETOOTH)] = BIT_MASK(KEY_BLUETOOTH) },
287 	},
288 	{
289 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
290 		.evbit = { BIT_MASK(EV_KEY) },
291 		.keybit = { [BIT_WORD(KEY_UWB)] = BIT_MASK(KEY_UWB) },
292 	},
293 	{
294 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
295 		.evbit = { BIT_MASK(EV_KEY) },
296 		.keybit = { [BIT_WORD(KEY_WIMAX)] = BIT_MASK(KEY_WIMAX) },
297 	},
298 	{
299 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT,
300 		.evbit = { BIT_MASK(EV_KEY) },
301 		.keybit = { [BIT_WORD(KEY_RFKILL)] = BIT_MASK(KEY_RFKILL) },
302 	},
303 	{
304 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_SWBIT,
305 		.evbit = { BIT(EV_SW) },
306 		.swbit = { [BIT_WORD(SW_RFKILL_ALL)] = BIT_MASK(SW_RFKILL_ALL) },
307 	},
308 	{ }
309 };
310 
311 static struct input_handler rfkill_handler = {
312 	.name =	"rfkill",
313 	.event = rfkill_event,
314 	.connect = rfkill_connect,
315 	.start = rfkill_start,
316 	.disconnect = rfkill_disconnect,
317 	.id_table = rfkill_ids,
318 };
319 
320 int __init rfkill_handler_init(void)
321 {
322 	switch (rfkill_master_switch_mode) {
323 	case RFKILL_INPUT_MASTER_UNBLOCKALL:
324 		rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNBLOCK;
325 		break;
326 	case RFKILL_INPUT_MASTER_RESTORE:
327 		rfkill_master_switch_op = RFKILL_GLOBAL_OP_RESTORE;
328 		break;
329 	case RFKILL_INPUT_MASTER_UNLOCK:
330 		rfkill_master_switch_op = RFKILL_GLOBAL_OP_UNLOCK;
331 		break;
332 	default:
333 		return -EINVAL;
334 	}
335 
336 	spin_lock_init(&rfkill_op_lock);
337 
338 	/* Avoid delay at first schedule */
339 	rfkill_last_scheduled =
340 			jiffies - msecs_to_jiffies(RFKILL_OPS_DELAY) - 1;
341 	return input_register_handler(&rfkill_handler);
342 }
343 
344 void __exit rfkill_handler_exit(void)
345 {
346 	input_unregister_handler(&rfkill_handler);
347 	cancel_delayed_work_sync(&rfkill_op_work);
348 }
349