blob: 74a1d30fae6ec0d26cd31e4e8e4d34ddcc7aee91 [file] [log] [blame]
Thomas Gleixner8e8e69d2019-05-29 07:17:59 -07001// SPDX-License-Identifier: GPL-2.0-only
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -03002/* ir-xmp-decoder.c - handle XMP IR Pulse/Space protocol
3 *
4 * Copyright (C) 2014 by Marcel Mol
5 *
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -03006 * - 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
9 */
10
11#include <linux/bitrev.h>
12#include <linux/module.h>
13#include "rc-core-priv.h"
14
15#define XMP_UNIT 136000 /* ns */
16#define XMP_LEADER 210000 /* ns */
17#define XMP_NIBBLE_PREFIX 760000 /* ns */
18#define XMP_HALFFRAME_SPACE 13800000 /* ns */
19#define XMP_TRAILER_SPACE 20000000 /* should be 80ms but not all dureation supliers can go that high */
20
21enum xmp_state {
22 STATE_INACTIVE,
23 STATE_LEADER_PULSE,
24 STATE_NIBBLE_SPACE,
25};
26
27/**
28 * ir_xmp_decode() - Decode one XMP pulse or space
29 * @dev: the struct rc_dev descriptor of the device
Mauro Carvalho Chehab1855e982017-11-29 03:46:30 -050030 * @ev: the struct ir_raw_event descriptor of the pulse/space
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -030031 *
32 * This function returns -EINVAL if the pulse violates the state machine
33 */
34static int ir_xmp_decode(struct rc_dev *dev, struct ir_raw_event ev)
35{
36 struct xmp_dec *data = &dev->raw->xmp;
37
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -030038 if (!is_timing_event(ev)) {
39 if (ev.reset)
40 data->state = STATE_INACTIVE;
41 return 0;
42 }
43
Sean Young50078a92018-02-12 07:20:52 -050044 dev_dbg(&dev->dev, "XMP decode started at state %d %d (%uus %s)\n",
45 data->state, data->count, TO_US(ev.duration), TO_STR(ev.pulse));
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -030046
47 switch (data->state) {
48
49 case STATE_INACTIVE:
50 if (!ev.pulse)
51 break;
52
53 if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2)) {
54 data->count = 0;
55 data->state = STATE_NIBBLE_SPACE;
56 }
57
58 return 0;
59
60 case STATE_LEADER_PULSE:
61 if (!ev.pulse)
62 break;
63
64 if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2))
65 data->state = STATE_NIBBLE_SPACE;
66
67 return 0;
68
69 case STATE_NIBBLE_SPACE:
70 if (ev.pulse)
71 break;
72
73 if (geq_margin(ev.duration, XMP_TRAILER_SPACE, XMP_NIBBLE_PREFIX)) {
74 int divider, i;
75 u8 addr, subaddr, subaddr2, toggle, oem, obc1, obc2, sum1, sum2;
76 u32 *n;
77 u32 scancode;
78
79 if (data->count != 16) {
Sean Young50078a92018-02-12 07:20:52 -050080 dev_dbg(&dev->dev, "received TRAILER period at index %d: %u\n",
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -030081 data->count, ev.duration);
82 data->state = STATE_INACTIVE;
83 return -EINVAL;
84 }
85
86 n = data->durations;
87 /*
88 * the 4th nibble should be 15 so base the divider on this
Mauro Carvalho Chehab04ad3012019-02-18 14:29:01 -050089 * to transform durations into nibbles. Subtract 2000 from
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -030090 * the divider to compensate for fluctuations in the signal
91 */
92 divider = (n[3] - XMP_NIBBLE_PREFIX) / 15 - 2000;
93 if (divider < 50) {
Sean Young50078a92018-02-12 07:20:52 -050094 dev_dbg(&dev->dev, "divider to small %d.\n",
95 divider);
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -030096 data->state = STATE_INACTIVE;
97 return -EINVAL;
98 }
99
100 /* convert to nibbles and do some sanity checks */
101 for (i = 0; i < 16; i++)
102 n[i] = (n[i] - XMP_NIBBLE_PREFIX) / divider;
103 sum1 = (15 + n[0] + n[1] + n[2] + n[3] +
104 n[4] + n[5] + n[6] + n[7]) % 16;
105 sum2 = (15 + n[8] + n[9] + n[10] + n[11] +
106 n[12] + n[13] + n[14] + n[15]) % 16;
107
108 if (sum1 != 15 || sum2 != 15) {
Sean Young50078a92018-02-12 07:20:52 -0500109 dev_dbg(&dev->dev, "checksum errors sum1=0x%X sum2=0x%X\n",
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300110 sum1, sum2);
111 data->state = STATE_INACTIVE;
112 return -EINVAL;
113 }
114
115 subaddr = n[0] << 4 | n[2];
116 subaddr2 = n[8] << 4 | n[11];
117 oem = n[4] << 4 | n[5];
118 addr = n[6] << 4 | n[7];
119 toggle = n[10];
120 obc1 = n[12] << 4 | n[13];
121 obc2 = n[14] << 4 | n[15];
122 if (subaddr != subaddr2) {
Sean Young50078a92018-02-12 07:20:52 -0500123 dev_dbg(&dev->dev, "subaddress nibbles mismatch 0x%02X != 0x%02X\n",
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300124 subaddr, subaddr2);
125 data->state = STATE_INACTIVE;
126 return -EINVAL;
127 }
128 if (oem != 0x44)
Sean Young50078a92018-02-12 07:20:52 -0500129 dev_dbg(&dev->dev, "Warning: OEM nibbles 0x%02X. Expected 0x44\n",
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300130 oem);
131
132 scancode = addr << 24 | subaddr << 16 |
133 obc1 << 8 | obc2;
Sean Young50078a92018-02-12 07:20:52 -0500134 dev_dbg(&dev->dev, "XMP scancode 0x%06x\n", scancode);
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300135
136 if (toggle == 0) {
Sean Young6d741bf2017-08-07 16:20:58 -0400137 rc_keydown(dev, RC_PROTO_XMP, scancode, 0);
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300138 } else {
139 rc_repeat(dev);
Sean Young50078a92018-02-12 07:20:52 -0500140 dev_dbg(&dev->dev, "Repeat last key\n");
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300141 }
142 data->state = STATE_INACTIVE;
143
144 return 0;
145
146 } else if (geq_margin(ev.duration, XMP_HALFFRAME_SPACE, XMP_NIBBLE_PREFIX)) {
147 /* Expect 8 or 16 nibble pulses. 16 in case of 'final' frame */
148 if (data->count == 16) {
Sean Young50078a92018-02-12 07:20:52 -0500149 dev_dbg(&dev->dev, "received half frame pulse at index %d. Probably a final frame key-up event: %u\n",
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300150 data->count, ev.duration);
151 /*
152 * TODO: for now go back to half frame position
153 * so trailer can be found and key press
154 * can be handled.
155 */
156 data->count = 8;
157 }
158
159 else if (data->count != 8)
Sean Young50078a92018-02-12 07:20:52 -0500160 dev_dbg(&dev->dev, "received half frame pulse at index %d: %u\n",
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300161 data->count, ev.duration);
162 data->state = STATE_LEADER_PULSE;
163
164 return 0;
165
166 } else if (geq_margin(ev.duration, XMP_NIBBLE_PREFIX, XMP_UNIT)) {
167 /* store nibble raw data, decode after trailer */
168 if (data->count == 16) {
Sean Young50078a92018-02-12 07:20:52 -0500169 dev_dbg(&dev->dev, "to many pulses (%d) ignoring: %u\n",
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300170 data->count, ev.duration);
171 data->state = STATE_INACTIVE;
172 return -EINVAL;
173 }
174 data->durations[data->count] = ev.duration;
175 data->count++;
176 data->state = STATE_LEADER_PULSE;
177
178 return 0;
179
180 }
181
182 break;
183 }
184
Sean Young50078a92018-02-12 07:20:52 -0500185 dev_dbg(&dev->dev, "XMP decode failed at count %d state %d (%uus %s)\n",
186 data->count, data->state, TO_US(ev.duration), TO_STR(ev.pulse));
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300187 data->state = STATE_INACTIVE;
188 return -EINVAL;
189}
190
191static struct ir_raw_handler xmp_handler = {
Sean Young6d741bf2017-08-07 16:20:58 -0400192 .protocols = RC_PROTO_BIT_XMP,
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300193 .decode = ir_xmp_decode,
Sean Younga86d6df2018-03-23 16:47:37 -0400194 .min_timeout = XMP_TRAILER_SPACE,
Marcel J.E. Mol1dee9b52014-07-26 17:28:26 -0300195};
196
197static int __init ir_xmp_decode_init(void)
198{
199 ir_raw_handler_register(&xmp_handler);
200
201 printk(KERN_INFO "IR XMP protocol handler initialized\n");
202 return 0;
203}
204
205static void __exit ir_xmp_decode_exit(void)
206{
207 ir_raw_handler_unregister(&xmp_handler);
208}
209
210module_init(ir_xmp_decode_init);
211module_exit(ir_xmp_decode_exit);
212
213MODULE_LICENSE("GPL");
214MODULE_AUTHOR("Marcel Mol <marcel@mesa.nl>");
215MODULE_AUTHOR("MESA Consulting (http://www.mesa.nl)");
216MODULE_DESCRIPTION("XMP IR protocol decoder");