1 /* ir-sharp-decoder.c - handle Sharp IR Pulse/Space protocol
3  * Copyright (C) 2013-2014 Imagination Technologies Ltd.
20 #include "rc-core-priv.h"
24 #define SHARP_BIT_PULSE		(8    * SHARP_UNIT) /* 320us */
25 #define SHARP_BIT_0_PERIOD	(25   * SHARP_UNIT) /* 1ms (680us space) */
40  * ir_sharp_decode() - Decode one Sharp pulse or space
44  * This function returns -EINVAL if the pulse violates the state machine
48 	struct sharp_dec *data = &dev->raw->sharp;  in ir_sharp_decode()
53 			data->state = STATE_INACTIVE;  in ir_sharp_decode()
57 	dev_dbg(&dev->dev, "Sharp decode started at state %d (%uus %s)\n",  in ir_sharp_decode()
58 		data->state, TO_US(ev.duration), TO_STR(ev.pulse));  in ir_sharp_decode()
60 	switch (data->state) {  in ir_sharp_decode()
66 		if (!eq_margin(ev.duration, SHARP_BIT_PULSE,  in ir_sharp_decode()
70 		data->count = 0;  in ir_sharp_decode()
71 		data->pulse_len = ev.duration;  in ir_sharp_decode()
72 		data->state = STATE_BIT_SPACE;  in ir_sharp_decode()
79 		if (!eq_margin(ev.duration, SHARP_BIT_PULSE,  in ir_sharp_decode()
83 		data->pulse_len = ev.duration;  in ir_sharp_decode()
84 		data->state = STATE_BIT_SPACE;  in ir_sharp_decode()
91 		data->bits <<= 1;  in ir_sharp_decode()
92 		if (eq_margin(data->pulse_len + ev.duration, SHARP_BIT_1_PERIOD,  in ir_sharp_decode()
94 			data->bits |= 1;  in ir_sharp_decode()
95 		else if (!eq_margin(data->pulse_len + ev.duration,  in ir_sharp_decode()
98 		data->count++;  in ir_sharp_decode()
100 		if (data->count == SHARP_NBITS ||  in ir_sharp_decode()
101 		    data->count == SHARP_NBITS * 2)  in ir_sharp_decode()
102 			data->state = STATE_TRAILER_PULSE;  in ir_sharp_decode()
104 			data->state = STATE_BIT_PULSE;  in ir_sharp_decode()
112 		if (!eq_margin(ev.duration, SHARP_BIT_PULSE,  in ir_sharp_decode()
116 		if (data->count == SHARP_NBITS) {  in ir_sharp_decode()
118 			if ((data->bits & 0x3) != 0x2 &&  in ir_sharp_decode()
120 			    (data->bits & 0x3) != 0x0)  in ir_sharp_decode()
122 			data->state = STATE_ECHO_SPACE;  in ir_sharp_decode()
124 			data->state = STATE_TRAILER_SPACE;  in ir_sharp_decode()
132 		if (!eq_margin(ev.duration, SHARP_ECHO_SPACE,  in ir_sharp_decode()
136 		data->state = STATE_BIT_PULSE;  in ir_sharp_decode()
144 		if (!geq_margin(ev.duration, SHARP_TRAILER_SPACE,  in ir_sharp_decode()
148 		/* Validate - command, ext, chk should be inverted in 2nd */  in ir_sharp_decode()
149 		msg = (data->bits >> 15) & 0x7fff;  in ir_sharp_decode()
150 		echo = data->bits & 0x7fff;  in ir_sharp_decode()
152 			dev_dbg(&dev->dev,  in ir_sharp_decode()
162 		dev_dbg(&dev->dev, "Sharp scancode 0x%04x\n", scancode);  in ir_sharp_decode()
165 		data->state = STATE_INACTIVE;  in ir_sharp_decode()
169 	dev_dbg(&dev->dev, "Sharp decode failed at count %d state %d (%uus %s)\n",  in ir_sharp_decode()
170 		data->count, data->state, TO_US(ev.duration), TO_STR(ev.pulse));  in ir_sharp_decode()
171 	data->state = STATE_INACTIVE;  in ir_sharp_decode()
172 	return -EINVAL;  in ir_sharp_decode()
187  * ir_sharp_encode() - Encode a scancode as a stream of raw events
195  *		-ENOBUFS if there isn't enough space in the array to fit the
212 	max -= ret;  in ir_sharp_encode()
221 	return e - events;  in ir_sharp_encode()