1 // SPDX-License-Identifier: GPL-2.0-only
2 /* ir-xmp-decoder.c - handle XMP IR Pulse/Space protocol
6  * - Based on info from http://www.hifi-remote.com
7  * - Ignore Toggle=9 frames
8  * - Ignore XMP-1 XMP-2 difference, always store 16 bit OBC
13 #include "rc-core-priv.h"
15 #define XMP_UNIT		  136 /* us */
16 #define XMP_LEADER		  210 /* us */
17 #define XMP_NIBBLE_PREFIX	  760 /* us */
18 #define	XMP_HALFFRAME_SPACE	13800 /* us */
19 /* should be 80ms but not all duration supliers can go that high */
29  * ir_xmp_decode() - Decode one XMP pulse or space
33  * This function returns -EINVAL if the pulse violates the state machine
37 	struct xmp_dec *data = &dev->raw->xmp;  in ir_xmp_decode()
41 			data->state = STATE_INACTIVE;  in ir_xmp_decode()
45 	dev_dbg(&dev->dev, "XMP decode started at state %d %d (%uus %s)\n",  in ir_xmp_decode()
46 		data->state, data->count, ev.duration, TO_STR(ev.pulse));  in ir_xmp_decode()
48 	switch (data->state) {  in ir_xmp_decode()
54 		if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2)) {  in ir_xmp_decode()
55 			data->count = 0;  in ir_xmp_decode()
56 			data->state = STATE_NIBBLE_SPACE;  in ir_xmp_decode()
65 		if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2))  in ir_xmp_decode()
66 			data->state = STATE_NIBBLE_SPACE;  in ir_xmp_decode()
74 		if (geq_margin(ev.duration, XMP_TRAILER_SPACE, XMP_NIBBLE_PREFIX)) {  in ir_xmp_decode()
80 			if (data->count != 16) {  in ir_xmp_decode()
81 				dev_dbg(&dev->dev, "received TRAILER period at index %d: %u\n",  in ir_xmp_decode()
82 					data->count, ev.duration);  in ir_xmp_decode()
83 				data->state = STATE_INACTIVE;  in ir_xmp_decode()
84 				return -EINVAL;  in ir_xmp_decode()
87 			n = data->durations;  in ir_xmp_decode()
93 			divider = (n[3] - XMP_NIBBLE_PREFIX) / 15 - 2000;  in ir_xmp_decode()
95 				dev_dbg(&dev->dev, "divider to small %d.\n",  in ir_xmp_decode()
97 				data->state = STATE_INACTIVE;  in ir_xmp_decode()
98 				return -EINVAL;  in ir_xmp_decode()
103 				n[i] = (n[i] - XMP_NIBBLE_PREFIX) / divider;  in ir_xmp_decode()
110 				dev_dbg(&dev->dev, "checksum errors sum1=0x%X sum2=0x%X\n",  in ir_xmp_decode()
112 				data->state = STATE_INACTIVE;  in ir_xmp_decode()
113 				return -EINVAL;  in ir_xmp_decode()
124 				dev_dbg(&dev->dev, "subaddress nibbles mismatch 0x%02X != 0x%02X\n",  in ir_xmp_decode()
126 				data->state = STATE_INACTIVE;  in ir_xmp_decode()
127 				return -EINVAL;  in ir_xmp_decode()
130 				dev_dbg(&dev->dev, "Warning: OEM nibbles 0x%02X. Expected 0x44\n",  in ir_xmp_decode()
135 			dev_dbg(&dev->dev, "XMP scancode 0x%06x\n", scancode);  in ir_xmp_decode()
141 				dev_dbg(&dev->dev, "Repeat last key\n");  in ir_xmp_decode()
143 			data->state = STATE_INACTIVE;  in ir_xmp_decode()
147 		} else if (geq_margin(ev.duration, XMP_HALFFRAME_SPACE, XMP_NIBBLE_PREFIX)) {  in ir_xmp_decode()
149 			if (data->count == 16) {  in ir_xmp_decode()
150 …dev_dbg(&dev->dev, "received half frame pulse at index %d. Probably a final frame key-up event: %u…  in ir_xmp_decode()
151 					data->count, ev.duration);  in ir_xmp_decode()
157 				data->count = 8;  in ir_xmp_decode()
160 			else if (data->count != 8)  in ir_xmp_decode()
161 				dev_dbg(&dev->dev, "received half frame pulse at index %d: %u\n",  in ir_xmp_decode()
162 					data->count, ev.duration);  in ir_xmp_decode()
163 			data->state = STATE_LEADER_PULSE;  in ir_xmp_decode()
167 		} else if (geq_margin(ev.duration, XMP_NIBBLE_PREFIX, XMP_UNIT)) {  in ir_xmp_decode()
169 			if (data->count == 16) {  in ir_xmp_decode()
170 				dev_dbg(&dev->dev, "too many pulses (%d) ignoring: %u\n",  in ir_xmp_decode()
171 					data->count, ev.duration);  in ir_xmp_decode()
172 				data->state = STATE_INACTIVE;  in ir_xmp_decode()
173 				return -EINVAL;  in ir_xmp_decode()
175 			data->durations[data->count] = ev.duration;  in ir_xmp_decode()
176 			data->count++;  in ir_xmp_decode()
177 			data->state = STATE_LEADER_PULSE;  in ir_xmp_decode()
186 	dev_dbg(&dev->dev, "XMP decode failed at count %d state %d (%uus %s)\n",  in ir_xmp_decode()
187 		data->count, data->state, ev.duration, TO_STR(ev.pulse));  in ir_xmp_decode()
188 	data->state = STATE_INACTIVE;  in ir_xmp_decode()
189 	return -EINVAL;  in ir_xmp_decode()