summaryrefslogtreecommitdiff
path: root/drivers/media/common/ir-functions.c
blob: 397cff8b345b2afc2b77b53d61f7d94c0658476f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
/*
 *
 * some common structs and functions to handle infrared remotes via
 * input layer ...
 *
 * (c) 2003 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/string.h>
#include <media/ir-common.h>

/* -------------------------------------------------------------------------- */

MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
MODULE_LICENSE("GPL");

static int repeat = 1;
module_param(repeat, int, 0444);
MODULE_PARM_DESC(repeat,"auto-repeat for IR keys (default: on)");

static int debug = 0;    /* debug level (0,1,2) */
module_param(debug, int, 0644);

#define dprintk(level, fmt, arg...)	if (debug >= level) \
	printk(KERN_DEBUG fmt , ## arg)

/* -------------------------------------------------------------------------- */

static void ir_input_key_event(struct input_dev *dev, struct ir_input_state *ir)
{
	if (KEY_RESERVED == ir->keycode) {
		printk(KERN_INFO "%s: unknown key: key=0x%02x raw=0x%02x down=%d\n",
		       dev->name,ir->ir_key,ir->ir_raw,ir->keypressed);
		return;
	}
	dprintk(1,"%s: key event code=%d down=%d\n",
		dev->name,ir->keycode,ir->keypressed);
	input_report_key(dev,ir->keycode,ir->keypressed);
	input_sync(dev);
}

/* -------------------------------------------------------------------------- */

void ir_input_init(struct input_dev *dev, struct ir_input_state *ir,
		   int ir_type, IR_KEYTAB_TYPE *ir_codes)
{
	int i;

	ir->ir_type = ir_type;
	if (ir_codes)
		memcpy(ir->ir_codes, ir_codes, sizeof(ir->ir_codes));


	dev->keycode     = ir->ir_codes;
	dev->keycodesize = sizeof(IR_KEYTAB_TYPE);
	dev->keycodemax  = IR_KEYTAB_SIZE;
	for (i = 0; i < IR_KEYTAB_SIZE; i++)
		set_bit(ir->ir_codes[i], dev->keybit);
	clear_bit(0, dev->keybit);

	set_bit(EV_KEY, dev->evbit);
	if (repeat)
		set_bit(EV_REP, dev->evbit);
}

void ir_input_nokey(struct input_dev *dev, struct ir_input_state *ir)
{
	if (ir->keypressed) {
		ir->keypressed = 0;
		ir_input_key_event(dev,ir);
	}
}

void ir_input_keydown(struct input_dev *dev, struct ir_input_state *ir,
		      u32 ir_key, u32 ir_raw)
{
	u32 keycode = IR_KEYCODE(ir->ir_codes, ir_key);

	if (ir->keypressed && ir->keycode != keycode) {
		ir->keypressed = 0;
		ir_input_key_event(dev,ir);
	}
	if (!ir->keypressed) {
		ir->ir_key  = ir_key;
		ir->ir_raw  = ir_raw;
		ir->keycode = keycode;
		ir->keypressed = 1;
		ir_input_key_event(dev,ir);
	}
}

/* -------------------------------------------------------------------------- */

u32 ir_extract_bits(u32 data, u32 mask)
{
	int mbit, vbit;
	u32 value;

	value = 0;
	vbit  = 0;
	for (mbit = 0; mbit < 32; mbit++) {
		if (!(mask & ((u32)1 << mbit)))
			continue;
		if (data & ((u32)1 << mbit))
			value |= (1 << vbit);
		vbit++;
	}
	return value;
}

static int inline getbit(u32 *samples, int bit)
{
	return (samples[bit/32] & (1 << (31-(bit%32)))) ? 1 : 0;
}

/* sump raw samples for visual debugging ;) */
int ir_dump_samples(u32 *samples, int count)
{
	int i, bit, start;

	printk(KERN_DEBUG "ir samples: ");
	start = 0;
	for (i = 0; i < count * 32; i++) {
		bit = getbit(samples,i);
		if (bit)
			start = 1;
		if (0 == start)
			continue;
		printk("%s", bit ? "#" : "_");
	}
	printk("\n");
	return 0;
}

/* decode raw samples, pulse distance coding used by NEC remotes */
int ir_decode_pulsedistance(u32 *samples, int count, int low, int high)
{
	int i,last,bit,len;
	u32 curBit;
	u32 value;

	/* find start burst */
	for (i = len = 0; i < count * 32; i++) {
		bit = getbit(samples,i);
		if (bit) {
			len++;
		} else {
			if (len >= 29)
				break;
			len = 0;
		}
	}

	/* start burst to short */
	if (len < 29)
		return 0xffffffff;

	/* find start silence */
	for (len = 0; i < count * 32; i++) {
		bit = getbit(samples,i);
		if (bit) {
			break;
		} else {
			len++;
		}
	}

	/* silence to short */
	if (len < 7)
		return 0xffffffff;

	/* go decoding */
	len   = 0;
	last = 1;
	value = 0; curBit = 1;
	for (; i < count * 32; i++) {
		bit  = getbit(samples,i);
		if (last) {
			if(bit) {
				continue;
			} else {
				len = 1;
			}
		} else {
			if (bit) {
				if (len > (low + high) /2)
					value |= curBit;
				curBit <<= 1;
				if (curBit == 1)
					break;
			} else {
				len++;
			}
		}
		last = bit;
	}

	return value;
}

/* decode raw samples, biphase coding, used by rc5 for example */
int ir_decode_biphase(u32 *samples, int count, int low, int high)
{
	int i,last,bit,len,flips;
	u32 value;

	/* find start bit (1) */
	for (i = 0; i < 32; i++) {
		bit = getbit(samples,i);
		if (bit)
			break;
	}

	/* go decoding */
	len   = 0;
	flips = 0;
	value = 1;
	for (; i < count * 32; i++) {
		if (len > high)
			break;
		if (flips > 1)
			break;
		last = bit;
		bit  = getbit(samples,i);
		if (last == bit) {
			len++;
			continue;
		}
		if (len < low) {
			len++;
			flips++;
			continue;
		}
		value <<= 1;
		value |= bit;
		flips = 0;
		len   = 1;
	}
	return value;
}

EXPORT_SYMBOL_GPL(ir_input_init);
EXPORT_SYMBOL_GPL(ir_input_nokey);
EXPORT_SYMBOL_GPL(ir_input_keydown);

EXPORT_SYMBOL_GPL(ir_extract_bits);
EXPORT_SYMBOL_GPL(ir_dump_samples);
EXPORT_SYMBOL_GPL(ir_decode_biphase);
EXPORT_SYMBOL_GPL(ir_decode_pulsedistance);

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */