1 // SPDX-License-Identifier: GPL-2.0
2 // ir-rc5-decoder.c - decoder for RC5(x) and StreamZap protocols
4 // Copyright (C) 2010 by Mauro Carvalho Chehab
5 // Copyright (C) 2010 by Jarod Wilson <jarod@redhat.com>
12 #include "rc-core-priv.h"
15 #define RC5_NBITS		14
16 #define RC5_SZ_NBITS		15
17 #define RC5X_NBITS		20
18 #define CHECK_RC5X_NBITS	8
19 #define RC5_UNIT		889 /* us */
20 #define RC5_BIT_START		(1 * RC5_UNIT)
21 #define RC5_BIT_END		(1 * RC5_UNIT)
22 #define RC5X_SPACE		(4 * RC5_UNIT)
23 #define RC5_TRAILER		(6 * RC5_UNIT) /* In reality, approx 100 */
34  * ir_rc5_decode() - Decode one RC-5 pulse or space
38  * This function returns -EINVAL if the pulse violates the state machine
42 	struct rc5_dec *data = &dev->raw->rc5;  in ir_rc5_decode()
49 			data->state = STATE_INACTIVE;  in ir_rc5_decode()
57 	dev_dbg(&dev->dev, "RC5(x/sz) decode started at state %i (%uus %s)\n",  in ir_rc5_decode()
58 		data->state, ev.duration, TO_STR(ev.pulse));  in ir_rc5_decode()
63 	switch (data->state) {  in ir_rc5_decode()
69 		data->state = STATE_BIT_START;  in ir_rc5_decode()
70 		data->count = 1;  in ir_rc5_decode()
76 			data->state = STATE_FINISHED;  in ir_rc5_decode()
83 		data->bits <<= 1;  in ir_rc5_decode()
85 			data->bits |= 1;  in ir_rc5_decode()
86 		data->count++;  in ir_rc5_decode()
87 		data->state = STATE_BIT_END;  in ir_rc5_decode()
91 		if (data->count == CHECK_RC5X_NBITS)  in ir_rc5_decode()
92 			data->state = STATE_CHECK_RC5X;  in ir_rc5_decode()
94 			data->state = STATE_BIT_START;  in ir_rc5_decode()
101 			data->is_rc5x = true;  in ir_rc5_decode()
104 			data->is_rc5x = false;  in ir_rc5_decode()
105 		data->state = STATE_BIT_START;  in ir_rc5_decode()
112 		if (data->is_rc5x && data->count == RC5X_NBITS) {  in ir_rc5_decode()
115 			if (!(dev->enabled_protocols & RC_PROTO_BIT_RC5X_20)) {  in ir_rc5_decode()
116 				data->state = STATE_INACTIVE;  in ir_rc5_decode()
119 			xdata    = (data->bits & 0x0003F) >> 0;  in ir_rc5_decode()
120 			command  = (data->bits & 0x00FC0) >> 6;  in ir_rc5_decode()
121 			system   = (data->bits & 0x1F000) >> 12;  in ir_rc5_decode()
122 			toggle   = (data->bits & 0x20000) ? 1 : 0;  in ir_rc5_decode()
123 			command += (data->bits & 0x40000) ? 0 : 0x40;  in ir_rc5_decode()
127 		} else if (!data->is_rc5x && data->count == RC5_NBITS) {  in ir_rc5_decode()
130 			if (!(dev->enabled_protocols & RC_PROTO_BIT_RC5)) {  in ir_rc5_decode()
131 				data->state = STATE_INACTIVE;  in ir_rc5_decode()
134 			command  = (data->bits & 0x0003F) >> 0;  in ir_rc5_decode()
135 			system   = (data->bits & 0x007C0) >> 6;  in ir_rc5_decode()
136 			toggle   = (data->bits & 0x00800) ? 1 : 0;  in ir_rc5_decode()
137 			command += (data->bits & 0x01000) ? 0 : 0x40;  in ir_rc5_decode()
141 		} else if (!data->is_rc5x && data->count == RC5_SZ_NBITS) {  in ir_rc5_decode()
144 			if (!(dev->enabled_protocols & RC_PROTO_BIT_RC5_SZ)) {  in ir_rc5_decode()
145 				data->state = STATE_INACTIVE;  in ir_rc5_decode()
148 			command  = (data->bits & 0x0003F) >> 0;  in ir_rc5_decode()
149 			system   = (data->bits & 0x02FC0) >> 6;  in ir_rc5_decode()
150 			toggle   = (data->bits & 0x01000) ? 1 : 0;  in ir_rc5_decode()
157 		dev_dbg(&dev->dev, "RC5(x/sz) scancode 0x%06x (p: %u, t: %u)\n",  in ir_rc5_decode()
161 		data->state = STATE_INACTIVE;  in ir_rc5_decode()
166 	dev_dbg(&dev->dev, "RC5(x/sz) decode failed at state %i count %d (%uus %s)\n",  in ir_rc5_decode()
167 		data->state, data->count, ev.duration, TO_STR(ev.pulse));  in ir_rc5_decode()
168 	data->state = STATE_INACTIVE;  in ir_rc5_decode()
169 	return -EINVAL;  in ir_rc5_decode()
197  * ir_rc5_encode() - Encode a scancode as a stream of raw events
202  * @max:	maximum size of @events
205  *		-ENOBUFS if there isn't enough space in the array to fit the
206  *		encoding. In this case all @max events will have been written.
207  *		-EINVAL if the scancode is ambiguous or invalid.
210 			 struct ir_raw_event *events, unsigned int max)  in ir_rc5_encode()  argument
225 		/* First bit is encoded by leader_pulse */  in ir_rc5_encode()
226 		ret = ir_raw_gen_manchester(&e, max, &ir_rc5_timings,  in ir_rc5_encode()
227 					    RC5_NBITS - 1, data);  in ir_rc5_encode()
240 		/* First bit is encoded by leader_pulse */  in ir_rc5_encode()
241 		pre_space_data = data >> (RC5X_NBITS - CHECK_RC5X_NBITS);  in ir_rc5_encode()
242 		ret = ir_raw_gen_manchester(&e, max, &ir_rc5x_timings[0],  in ir_rc5_encode()
243 					    CHECK_RC5X_NBITS - 1,  in ir_rc5_encode()
247 		ret = ir_raw_gen_manchester(&e, max - (e - events),  in ir_rc5_encode()
249 					    RC5X_NBITS - CHECK_RC5X_NBITS,  in ir_rc5_encode()
254 		/* RC5-SZ scancode is raw enough for Manchester as it is */  in ir_rc5_encode()
255 		/* First bit is encoded by leader_pulse */  in ir_rc5_encode()
256 		ret = ir_raw_gen_manchester(&e, max, &ir_rc5_sz_timings,  in ir_rc5_encode()
257 					    RC5_SZ_NBITS - 1,  in ir_rc5_encode()
262 		return -EINVAL;  in ir_rc5_encode()
265 	return e - events;  in ir_rc5_encode()