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
26enum 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
36static enum rfkill_input_master_mode rfkill_master_switch_mode =
37					RFKILL_INPUT_MASTER_UNBLOCKALL;
38module_param_named(master_switch_mode, rfkill_master_switch_mode, uint, 0);
39MODULE_PARM_DESC(master_switch_mode,
40	"SW_RFKILL_ALL ON should: 0=do nothing (only unlock); 1=restore; 2=unblock all");
41
42static spinlock_t rfkill_op_lock;
43static bool rfkill_op_pending;
44static unsigned long rfkill_sw_pending[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
45static unsigned long rfkill_sw_state[BITS_TO_LONGS(NUM_RFKILL_TYPES)];
46
47enum 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
54static enum rfkill_sched_op rfkill_master_switch_op;
55static enum rfkill_sched_op rfkill_op;
56
57static 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
85static 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
97static 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
140static DECLARE_DELAYED_WORK(rfkill_op_work, rfkill_op_handler);
141static unsigned long rfkill_last_scheduled;
142
143static 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
149static 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
156static 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
172static 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
188static 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
196static 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
221static 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
253static 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
270static void rfkill_disconnect(struct input_handle *handle)
271{
272	input_close_device(handle);
273	input_unregister_handle(handle);
274	kfree(handle);
275}
276
277static 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
311static 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
320int __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
344void __exit rfkill_handler_exit(void)
345{
346	input_unregister_handler(&rfkill_handler);
347	cancel_delayed_work_sync(&rfkill_op_work);
348}
349