1 // SPDX-License-Identifier: GPL-2.0
2 // ir-nec-decoder.c - handle NEC IR Pulse/Space protocol
8 #include "rc-core-priv.h"
33  * ir_nec_decode() - Decode one NEC pulse or space
37  * This function returns -EINVAL if the pulse violates the state machine
41 	struct nec_dec *data = &dev->raw->nec;  in ir_nec_decode()
48 			data->state = STATE_INACTIVE;  in ir_nec_decode()
52 	dev_dbg(&dev->dev, "NEC decode started at state %d (%uus %s)\n",  in ir_nec_decode()
53 		data->state, ev.duration, TO_STR(ev.pulse));  in ir_nec_decode()
55 	switch (data->state) {  in ir_nec_decode()
62 			data->is_nec_x = false;  in ir_nec_decode()
63 			data->necx_repeat = false;  in ir_nec_decode()
65 			data->is_nec_x = true;  in ir_nec_decode()
69 		data->count = 0;  in ir_nec_decode()
70 		data->state = STATE_HEADER_SPACE;  in ir_nec_decode()
78 			data->state = STATE_BIT_PULSE;  in ir_nec_decode()
81 			data->state = STATE_TRAILER_PULSE;  in ir_nec_decode()
94 		data->state = STATE_BIT_SPACE;  in ir_nec_decode()
101 		if (data->necx_repeat && data->count == NECX_REPEAT_BITS &&  in ir_nec_decode()
103 			dev_dbg(&dev->dev, "Repeat last key\n");  in ir_nec_decode()
105 			data->state = STATE_INACTIVE;  in ir_nec_decode()
107 		} else if (data->count > NECX_REPEAT_BITS)  in ir_nec_decode()
108 			data->necx_repeat = false;  in ir_nec_decode()
110 		data->bits <<= 1;  in ir_nec_decode()
112 			data->bits |= 1;  in ir_nec_decode()
115 		data->count++;  in ir_nec_decode()
117 		if (data->count == NEC_NBITS)  in ir_nec_decode()
118 			data->state = STATE_TRAILER_PULSE;  in ir_nec_decode()
120 			data->state = STATE_BIT_PULSE;  in ir_nec_decode()
131 		data->state = STATE_TRAILER_SPACE;  in ir_nec_decode()
141 		if (data->count == NEC_NBITS) {  in ir_nec_decode()
142 			address     = bitrev8((data->bits >> 24) & 0xff);  in ir_nec_decode()
143 			not_address = bitrev8((data->bits >> 16) & 0xff);  in ir_nec_decode()
144 			command	    = bitrev8((data->bits >>  8) & 0xff);  in ir_nec_decode()
145 			not_command = bitrev8((data->bits >>  0) & 0xff);  in ir_nec_decode()
153 			if (data->is_nec_x)  in ir_nec_decode()
154 				data->necx_repeat = true;  in ir_nec_decode()
161 		data->state = STATE_INACTIVE;  in ir_nec_decode()
165 	dev_dbg(&dev->dev, "NEC decode failed at count %d state %d (%uus %s)\n",  in ir_nec_decode()
166 		data->count, data->state, ev.duration, TO_STR(ev.pulse));  in ir_nec_decode()
167 	data->state = STATE_INACTIVE;  in ir_nec_decode()
168 	return -EINVAL;  in ir_nec_decode()
172  * ir_nec_scancode_to_raw() - encode an NEC scancode ready for modulation.
183 		/* 32-bit NEC (used by Apple and TiVo remotes) */  in ir_nec_scancode_to_raw()
184 		/* scan encoding: aaAAddDD */  in ir_nec_scancode_to_raw()
190 		/* scan encoding AAaaDD */  in ir_nec_scancode_to_raw()
196 		/* scan encoding: AADD */  in ir_nec_scancode_to_raw()
221  * ir_nec_encode() - Encode a scancode as a stream of raw events
229  *		-ENOBUFS if there isn't enough space in the array to fit the
247 	return e - events;  in ir_nec_encode()